Merge branch 'master' of /home/tglx/work/mtd/git/linux-2.6.git/

22 files changed, 5081 insertions, 1598 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 9709fac6531d..50a7749cfca1 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -1,18 +1,15 @@
 ToDo/Notes:
 	- Find and fix bugs.
-	- In between ntfs_prepare/commit_write, need exclusion between
-	  simultaneous file extensions.  This is given to us by holding i_sem
-	  on the inode.  The only places in the kernel when a file is resized
-	  are prepare/commit write and truncate for both of which i_sem is
-	  held.  Just have to be careful in readpage/writepage and all other
-	  helpers not running under i_sem that we play nice...
-	  Also need to be careful with initialized_size extention in
-	  ntfs_prepare_write. Basically, just be _very_ careful in this code...
-	  UPDATE: The only things that need to be checked are read/writepage
-	  which do not hold i_sem.  Note writepage cannot change i_size but it
-	  needs to cope with a concurrent i_size change, just like readpage.
-	  Also both need to cope with concurrent changes to the other sizes,
-	  i.e. initialized/allocated/compressed size, as well.
+	- The only places in the kernel where a file is resized are
+	  ntfs_file_write*() and ntfs_truncate() for both of which i_sem is
+	  held.  Just have to be careful in read-/writepage and other helpers
+	  not running under i_sem that we play nice...  Also need to be careful
+	  with initialized_size extension in ntfs_file_write*() and writepage.
+	  UPDATE: The only things that need to be checked are the compressed
+	  write and the other attribute resize/write cases like index
+	  attributes, etc.  For now none of these are implemented so are safe.
+	- Implement filling in of holes in aops.c::ntfs_writepage() and its
+	  helpers.
 	- Implement mft.c::sync_mft_mirror_umount().  We currently will just
 	  leave the volume dirty on umount if the final iput(vol->mft_ino)
 	  causes a write of any mirrored mft records due to the mft mirror
@@ -22,6 +19,152 @@ ToDo/Notes:
 	- Enable the code for setting the NT4 compatibility flag when we start
 	  making NTFS 1.2 specific modifications.
 
+2.1.25 - (Almost) fully implement write(2) and truncate(2).
+
+	- Change ntfs_map_runlist_nolock(), ntfs_attr_find_vcn_nolock() and
+	  {__,}ntfs_cluster_free() to also take an optional attribute search
+	  context as argument.  This allows calling these functions with the
+	  mft record mapped.  Update all callers.
+	- Fix potential deadlock in ntfs_mft_data_extend_allocation_nolock()
+	  error handling by passing in the active search context when calling
+	  ntfs_cluster_free().
+	- Change ntfs_cluster_alloc() to take an extra boolean parameter
+	  specifying whether the cluster are being allocated to extend an
+	  attribute or to fill a hole.
+	- Change ntfs_attr_make_non_resident() to call ntfs_cluster_alloc()
+	  with @is_extension set to TRUE and remove the runlist terminator
+	  fixup code as this is now done by ntfs_cluster_alloc().
+	- Change ntfs_attr_make_non_resident to take the attribute value size
+	  as an extra parameter.  This is needed since we need to know the size
+	  before we can map the mft record and our callers always know it.  The
+	  reason we cannot simply read the size from the vfs inode i_size is
+	  that this is not necessarily uptodate.  This happens when
+	  ntfs_attr_make_non_resident() is called in the ->truncate call path.
+	- Fix ntfs_attr_make_non_resident() to update the vfs inode i_blocks
+	  which is zero for a resident attribute but should no longer be zero
+	  once the attribute is non-resident as it then has real clusters
+	  allocated.
+	- Add fs/ntfs/attrib.[hc]::ntfs_attr_extend_allocation(), a function to
+	  extend the allocation of an attributes.  Optionally, the data size,
+	  but not the initialized size can be extended, too.
+	- Implement fs/ntfs/inode.[hc]::ntfs_truncate().  It only supports
+	  uncompressed and unencrypted files and it never creates sparse files
+	  at least for the moment (making a file sparse requires us to modify
+	  its directory entries and we do not support directory operations at
+	  the moment).  Also, support for highly fragmented files, i.e. ones
+	  whose data attribute is split across multiple extents, is severly
+	  limited.  When such a case is encountered, EOPNOTSUPP is returned.
+	- Enable ATTR_SIZE attribute changes in ntfs_setattr().  This completes
+	  the initial implementation of file truncation.  Now both open(2)ing
+	  a file with the O_TRUNC flag and the {,f}truncate(2) system calls
+	  will resize a file appropriately.  The limitations are that only
+	  uncompressed and unencrypted files are supported.  Also, there is
+	  only very limited support for highly fragmented files (the ones whose
+	  $DATA attribute is split into multiple attribute extents).
+	- In attrib.c::ntfs_attr_set() call balance_dirty_pages_ratelimited()
+	  and cond_resched() in the main loop as we could be dirtying a lot of
+	  pages and this ensures we play nice with the VM and the system as a
+	  whole.
+	- Implement file operations ->write, ->aio_write, ->writev for regular
+	  files.  This replaces the old use of generic_file_write(), et al and
+	  the address space operations ->prepare_write and ->commit_write.
+	  This means that both sparse and non-sparse (unencrypted and
+	  uncompressed) files can now be extended using the normal write(2)
+	  code path.  There are two limitations at present and these are that
+	  we never create sparse files and that we only have limited support
+	  for highly fragmented files, i.e. ones whose data attribute is split
+	  across multiple extents.   When such a case is encountered,
+	  EOPNOTSUPP is returned.
+	- $EA attributes can be both resident and non-resident.
+	- Use %z for size_t to fix compilation warnings.  (Andrew Morton)
+	- Fix compilation warnings with gcc-4.0.2 on SUSE 10.0.
+	- Document extended attribute ($EA) NEED_EA flag.  (Based on libntfs
+	  patch by Yura Pakhuchiy.)
+
+2.1.24 - Lots of bug fixes and support more clean journal states.
+
+	- Support journals ($LogFile) which have been modified by chkdsk.  This
+	  means users can boot into Windows after we marked the volume dirty.
+	  The Windows boot will run chkdsk and then reboot.  The user can then
+	  immediately boot into Linux rather than having to do a full Windows
+	  boot first before rebooting into Linux and we will recognize such a
+	  journal and empty it as it is clean by definition.  Note, this only
+	  works if chkdsk left the journal in an obviously clean state.
+	- Support journals ($LogFile) with only one restart page as well as
+	  journals with two different restart pages.  We sanity check both and
+	  either use the only sane one or the more recent one of the two in the
+	  case that both are valid.
+	- Add fs/ntfs/malloc.h::ntfs_malloc_nofs_nofail() which is analogous to
+	  ntfs_malloc_nofs() but it performs allocations with __GFP_NOFAIL and
+	  hence cannot fail.
+	- Use ntfs_malloc_nofs_nofail() in the two critical regions in
+	  fs/ntfs/runlist.c::ntfs_runlists_merge().  This means we no longer
+	  need to panic() if the allocation fails as it now cannot fail.
+	- Fix two nasty runlist merging bugs that had gone unnoticed so far.
+	  Thanks to Stefano Picerno for the bug report.
+	- Remove two bogus BUG_ON()s from fs/ntfs/mft.c.
+	- Fix handling of valid but empty mapping pairs array in
+	  fs/ntfs/runlist.c::ntfs_mapping_pairs_decompress().
+	- Report unrepresentable inodes during ntfs_readdir() as KERN_WARNING
+	  messages and include the inode number.  Thanks to Yura Pakhuchiy for
+	  pointing this out.
+	- Change ntfs_rl_truncate_nolock() to throw away the runlist if the new
+	  length is zero.
+	- Add runlist.[hc]::ntfs_rl_punch_nolock() which punches a caller
+	  specified hole into a runlist.
+	- Fix a bug in fs/ntfs/index.c::ntfs_index_lookup().  When the returned
+	  index entry is in the index root, we forgot to set the @ir pointer in
+	  the index context.  Thanks to Yura Pakhuchiy for finding this bug.
+	- Remove bogus setting of PageError in ntfs_read_compressed_block().
+	- Add fs/ntfs/attrib.[hc]::ntfs_resident_attr_value_resize().
+	- Fix a bug in ntfs_map_runlist_nolock() where we forgot to protect
+	  access to the allocated size in the ntfs inode with the size lock.
+	- Fix ntfs_attr_vcn_to_lcn_nolock() and ntfs_attr_find_vcn_nolock() to
+	  return LCN_ENOENT when there is no runlist and the allocated size is
+	  zero.
+	- Fix load_attribute_list() to handle the case of a NULL runlist.
+	- Fix handling of sparse attributes in ntfs_attr_make_non_resident().
+	- Add BUG() checks to ntfs_attr_make_non_resident() and ntfs_attr_set()
+	  to ensure that these functions are never called for compressed or
+	  encrypted attributes.
+	- Fix cluster (de)allocators to work when the runlist is NULL and more
+	  importantly to take a locked runlist rather than them locking it
+	  which leads to lock reversal.
+	- Truncate {a,c,m}time to the ntfs supported time granularity when
+	  updating the times in the inode in ntfs_setattr().
+	- Fixup handling of sparse, compressed, and encrypted attributes in
+	  fs/ntfs/inode.c::ntfs_read_locked_{,attr_,index_}inode(),
+	  fs/ntfs/aops.c::ntfs_{read,write}page().
+	- Make ntfs_write_block() not instantiate sparse blocks if they contain
+	  only zeroes.
+	- Optimize fs/ntfs/aops.c::ntfs_write_block() by extending the page
+	  lock protection over the buffer submission for i/o which allows the
+	  removal of the get_bh()/put_bh() pairs for each buffer.
+	- Fix fs/ntfs/aops.c::ntfs_{read,write}_block() to handle the case
+	  where a concurrent truncate has truncated the runlist under our feet.
+	- Fix page_has_buffers()/page_buffers() handling in fs/ntfs/aops.c.
+	- In fs/ntfs/aops.c::ntfs_end_buffer_async_read(), use a bit spin lock
+	  in the first buffer head instead of a driver global spin lock to
+	  improve scalability.
+	- Minor fix to error handling and error message display in
+	  fs/ntfs/aops.c::ntfs_prepare_nonresident_write().
+	- Change the mount options {u,f,d}mask to always parse the number as
+	  an octal number to conform to how chmod(1) works, too.  Thanks to
+	  Giuseppe Bilotta and Horst von Brand for pointing out the errors of
+	  my ways.
+	- Fix various bugs in the runlist merging code.  (Based on libntfs
+	  changes by Richard Russon.)
+	- Fix sparse warnings that have crept in over time.
+	- Change ntfs_cluster_free() to require a write locked runlist on entry
+	  since we otherwise get into a lock reversal deadlock if a read locked
+	  runlist is passed in. In the process also change it to take an ntfs
+	  inode instead of a vfs inode as parameter.
+	- Fix the definition of the CHKD ntfs record magic.  It had an off by
+	  two error causing it to be CHKB instead of CHKD.
+	- Fix a stupid bug in __ntfs_bitmap_set_bits_in_run() which caused the
+	  count to become negative and hence we had a wild memset() scribbling
+	  all over the system's ram.
+
 2.1.23 - Implement extension of resident files and make writing safe as well as
 	 many bug fixes, cleanups, and enhancements...
 
@@ -174,6 +317,9 @@ ToDo/Notes:
 	  fact that the vfs and ntfs inodes are one struct in memory to find
 	  the ntfs inode in memory if present.  Also, the ntfs inode has its
 	  own locking so it does not matter if the vfs inode is locked.
+	- Fix bug in mft record writing where we forgot to set the device in
+	  the buffers when mapping them after the VM had discarded them.
+	  Thanks to Martin MOKREJŠ for the bug report.
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 
diff --git a/fs/ntfs/Makefile b/fs/ntfs/Makefile
index f083f27d8b69..d0d45d1c853a 100644
--- a/fs/ntfs/Makefile
+++ b/fs/ntfs/Makefile
@@ -6,7 +6,7 @@ ntfs-objs := aops.o attrib.o collate.o compress.o debug.o dir.o file.o \
 	     index.o inode.o mft.o mst.o namei.o runlist.o super.o sysctl.o \
 	     unistr.o upcase.o
 
-EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.23\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.25\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 3f43bfe6184e..1c0a4315876a 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -27,6 +27,7 @@
 #include <linux/swap.h>
 #include <linux/buffer_head.h>
 #include <linux/writeback.h>
+#include <linux/bit_spinlock.h>
 
 #include "aops.h"
 #include "attrib.h"
@@ -55,45 +56,56 @@
  */
 static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 {
-	static DEFINE_SPINLOCK(page_uptodate_lock);
 	unsigned long flags;
-	struct buffer_head *tmp;
+	struct buffer_head *first, *tmp;
 	struct page *page;
+	struct inode *vi;
 	ntfs_inode *ni;
 	int page_uptodate = 1;
 
 	page = bh->b_page;
-	ni = NTFS_I(page->mapping->host);
+	vi = page->mapping->host;
+	ni = NTFS_I(vi);
 
 	if (likely(uptodate)) {
-		s64 file_ofs, initialized_size;
+		loff_t i_size;
+		s64 file_ofs, init_size;
 
 		set_buffer_uptodate(bh);
 
 		file_ofs = ((s64)page->index << PAGE_CACHE_SHIFT) +
 				bh_offset(bh);
 		read_lock_irqsave(&ni->size_lock, flags);
-		initialized_size = ni->initialized_size;
+		init_size = ni->initialized_size;
+		i_size = i_size_read(vi);
 		read_unlock_irqrestore(&ni->size_lock, flags);
+		if (unlikely(init_size > i_size)) {
+			/* Race with shrinking truncate. */
+			init_size = i_size;
+		}
 		/* Check for the current buffer head overflowing. */
-		if (file_ofs + bh->b_size > initialized_size) {
-			char *addr;
-			int ofs = 0;
-
-			if (file_ofs < initialized_size)
-				ofs = initialized_size - file_ofs;
-			addr = kmap_atomic(page, KM_BIO_SRC_IRQ);
-			memset(addr + bh_offset(bh) + ofs, 0, bh->b_size - ofs);
+		if (unlikely(file_ofs + bh->b_size > init_size)) {
+			u8 *kaddr;
+			int ofs;
+
+			ofs = 0;
+			if (file_ofs < init_size)
+				ofs = init_size - file_ofs;
+			kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
+			memset(kaddr + bh_offset(bh) + ofs, 0,
+					bh->b_size - ofs);
+			kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
 			flush_dcache_page(page);
-			kunmap_atomic(addr, KM_BIO_SRC_IRQ);
 		}
 	} else {
 		clear_buffer_uptodate(bh);
-		ntfs_error(ni->vol->sb, "Buffer I/O error, logical block %llu.",
-				(unsigned long long)bh->b_blocknr);
 		SetPageError(page);
+		ntfs_error(ni->vol->sb, "Buffer I/O error, logical block "
+				"0x%llx.", (unsigned long long)bh->b_blocknr);
 	}
-	spin_lock_irqsave(&page_uptodate_lock, flags);
+	first = page_buffers(page);
+	local_irq_save(flags);
+	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
 	clear_buffer_async_read(bh);
 	unlock_buffer(bh);
 	tmp = bh;
@@ -108,7 +120,8 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 		}
 		tmp = tmp->b_this_page;
 	} while (tmp != bh);
-	spin_unlock_irqrestore(&page_uptodate_lock, flags);
+	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+	local_irq_restore(flags);
 	/*
 	 * If none of the buffers had errors then we can set the page uptodate,
 	 * but we first have to perform the post read mst fixups, if the
@@ -121,7 +134,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 		if (likely(page_uptodate && !PageError(page)))
 			SetPageUptodate(page);
 	} else {
-		char *addr;
+		u8 *kaddr;
 		unsigned int i, recs;
 		u32 rec_size;
 
@@ -129,19 +142,20 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 		recs = PAGE_CACHE_SIZE / rec_size;
 		/* Should have been verified before we got here... */
 		BUG_ON(!recs);
-		addr = kmap_atomic(page, KM_BIO_SRC_IRQ);
+		kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
 		for (i = 0; i < recs; i++)
-			post_read_mst_fixup((NTFS_RECORD*)(addr +
+			post_read_mst_fixup((NTFS_RECORD*)(kaddr +
 					i * rec_size), rec_size);
+		kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
 		flush_dcache_page(page);
-		kunmap_atomic(addr, KM_BIO_SRC_IRQ);
 		if (likely(page_uptodate && !PageError(page)))
 			SetPageUptodate(page);
 	}
 	unlock_page(page);
 	return;
 still_busy:
-	spin_unlock_irqrestore(&page_uptodate_lock, flags);
+	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+	local_irq_restore(flags);
 	return;
 }
 
@@ -164,8 +178,11 @@ still_busy:
  */
 static int ntfs_read_block(struct page *page)
 {
+	loff_t i_size;
 	VCN vcn;
 	LCN lcn;
+	s64 init_size;
+	struct inode *vi;
 	ntfs_inode *ni;
 	ntfs_volume *vol;
 	runlist_element *rl;
@@ -176,7 +193,8 @@ static int ntfs_read_block(struct page *page)
 	int i, nr;
 	unsigned char blocksize_bits;
 
-	ni = NTFS_I(page->mapping->host);
+	vi = page->mapping->host;
+	ni = NTFS_I(vi);
 	vol = ni->vol;
 
 	/* $MFT/$DATA must have its complete runlist in memory at all times. */
@@ -185,25 +203,45 @@ static int ntfs_read_block(struct page *page)
 	blocksize_bits = VFS_I(ni)->i_blkbits;
 	blocksize = 1 << blocksize_bits;
 
-	if (!page_has_buffers(page))
+	if (!page_has_buffers(page)) {
 		create_empty_buffers(page, blocksize, 0);
-	bh = head = page_buffers(page);
-	if (unlikely(!bh)) {
-		unlock_page(page);
-		return -ENOMEM;
+		if (unlikely(!page_has_buffers(page))) {
+			unlock_page(page);
+			return -ENOMEM;
+		}
 	}
+	bh = head = page_buffers(page);
+	BUG_ON(!bh);
 
+	/*
+	 * We may be racing with truncate.  To avoid some of the problems we
+	 * now take a snapshot of the various sizes and use those for the whole
+	 * of the function.  In case of an extending truncate it just means we
+	 * may leave some buffers unmapped which are now allocated.  This is
+	 * not a problem since these buffers will just get mapped when a write
+	 * occurs.  In case of a shrinking truncate, we will detect this later
+	 * on due to the runlist being incomplete and if the page is being
+	 * fully truncated, truncate will throw it away as soon as we unlock
+	 * it so no need to worry what we do with it.
+	 */
 	iblock = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
 	read_lock_irqsave(&ni->size_lock, flags);
 	lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits;
-	zblock = (ni->initialized_size + blocksize - 1) >> blocksize_bits;
+	init_size = ni->initialized_size;
+	i_size = i_size_read(vi);
 	read_unlock_irqrestore(&ni->size_lock, flags);
+	if (unlikely(init_size > i_size)) {
+		/* Race with shrinking truncate. */
+		init_size = i_size;
+	}
+	zblock = (init_size + blocksize - 1) >> blocksize_bits;
 
 	/* Loop through all the buffers in the page. */
 	rl = NULL;
 	nr = i = 0;
 	do {
 		u8 *kaddr;
+		int err;
 
 		if (unlikely(buffer_uptodate(bh)))
 			continue;
@@ -211,6 +249,7 @@ static int ntfs_read_block(struct page *page)
 			arr[nr++] = bh;
 			continue;
 		}
+		err = 0;
 		bh->b_bdev = vol->sb->s_bdev;
 		/* Is the block within the allowed limits? */
 		if (iblock < lblock) {
@@ -252,7 +291,6 @@ lock_retry_remap:
 				goto handle_hole;
 			/* If first try and runlist unmapped, map and retry. */
 			if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
-				int err;
 				is_retry = TRUE;
 				/*
 				 * Attempt to map runlist, dropping lock for
@@ -263,20 +301,30 @@ lock_retry_remap:
 				if (likely(!err))
 					goto lock_retry_remap;
 				rl = NULL;
-				lcn = err;
 			} else if (!rl)
 				up_read(&ni->runlist.lock);
+			/*
+			 * If buffer is outside the runlist, treat it as a
+			 * hole.  This can happen due to concurrent truncate
+			 * for example.
+			 */
+			if (err == -ENOENT || lcn == LCN_ENOENT) {
+				err = 0;
+				goto handle_hole;
+			}
 			/* Hard error, zero out region. */
+			if (!err)
+				err = -EIO;
 			bh->b_blocknr = -1;
 			SetPageError(page);
 			ntfs_error(vol->sb, "Failed to read from inode 0x%lx, "
 					"attribute type 0x%x, vcn 0x%llx, "
 					"offset 0x%x because its location on "
 					"disk could not be determined%s "
-					"(error code %lli).", ni->mft_no,
+					"(error code %i).", ni->mft_no,
 					ni->type, (unsigned long long)vcn,
 					vcn_ofs, is_retry ? " even after "
-					"retrying" : "", (long long)lcn);
+					"retrying" : "", err);
 		}
 		/*
 		 * Either iblock was outside lblock limits or
@@ -289,9 +337,10 @@ handle_hole:
 handle_zblock:
 		kaddr = kmap_atomic(page, KM_USER0);
 		memset(kaddr + i * blocksize, 0, blocksize);
-		flush_dcache_page(page);
 		kunmap_atomic(kaddr, KM_USER0);
-		set_buffer_uptodate(bh);
+		flush_dcache_page(page);
+		if (likely(!err))
+			set_buffer_uptodate(bh);
 	} while (i++, iblock++, (bh = bh->b_this_page) != head);
 
 	/* Release the lock if we took it. */
@@ -348,6 +397,8 @@ handle_zblock:
  */
 static int ntfs_readpage(struct file *file, struct page *page)
 {
+	loff_t i_size;
+	struct inode *vi;
 	ntfs_inode *ni, *base_ni;
 	u8 *kaddr;
 	ntfs_attr_search_ctx *ctx;
@@ -366,32 +417,42 @@ retry_readpage:
 		unlock_page(page);
 		return 0;
 	}
-	ni = NTFS_I(page->mapping->host);
-
+	vi = page->mapping->host;
+	ni = NTFS_I(vi);
+	/*
+	 * Only $DATA attributes can be encrypted and only unnamed $DATA
+	 * attributes can be compressed.  Index root can have the flags set but
+	 * this means to create compressed/encrypted files, not that the
+	 * attribute is compressed/encrypted.  Note we need to check for
+	 * AT_INDEX_ALLOCATION since this is the type of both directory and
+	 * index inodes.
+	 */
+	if (ni->type != AT_INDEX_ALLOCATION) {
+		/* If attribute is encrypted, deny access, just like NT4. */
+		if (NInoEncrypted(ni)) {
+			BUG_ON(ni->type != AT_DATA);
+			err = -EACCES;
+			goto err_out;
+		}
+		/* Compressed data streams are handled in compress.c. */
+		if (NInoNonResident(ni) && NInoCompressed(ni)) {
+			BUG_ON(ni->type != AT_DATA);
+			BUG_ON(ni->name_len);
+			return ntfs_read_compressed_block(page);
+		}
+	}
 	/* NInoNonResident() == NInoIndexAllocPresent() */
 	if (NInoNonResident(ni)) {
-		/*
-		 * Only unnamed $DATA attributes can be compressed or
-		 * encrypted.
-		 */
-		if (ni->type == AT_DATA && !ni->name_len) {
-			/* If file is encrypted, deny access, just like NT4. */
-			if (NInoEncrypted(ni)) {
-				err = -EACCES;
-				goto err_out;
-			}
-			/* Compressed data streams are handled in compress.c. */
-			if (NInoCompressed(ni))
-				return ntfs_read_compressed_block(page);
-		}
-		/* Normal data stream. */
+		/* Normal, non-resident data stream. */
 		return ntfs_read_block(page);
 	}
 	/*
 	 * Attribute is resident, implying it is not compressed or encrypted.
 	 * This also means the attribute is smaller than an mft record and
 	 * hence smaller than a page, so can simply zero out any pages with
-	 * index above 0.
+	 * index above 0.  Note the attribute can actually be marked compressed
+	 * but if it is resident the actual data is not compressed so we are
+	 * ok to ignore the compressed flag here.
 	 */
 	if (unlikely(page->index > 0)) {
 		kaddr = kmap_atomic(page, KM_USER0);
@@ -431,7 +492,12 @@ retry_readpage:
 	read_lock_irqsave(&ni->size_lock, flags);
 	if (unlikely(attr_len > ni->initialized_size))
 		attr_len = ni->initialized_size;
+	i_size = i_size_read(vi);
 	read_unlock_irqrestore(&ni->size_lock, flags);
+	if (unlikely(attr_len > i_size)) {
+		/* Race with shrinking truncate. */
+		attr_len = i_size;
+	}
 	kaddr = kmap_atomic(page, KM_USER0);
 	/* Copy the data to the page. */
 	memcpy(kaddr, (u8*)ctx->attr +
@@ -511,19 +577,21 @@ static int ntfs_write_block(struct page *page, struct writeback_control *wbc)
 		BUG_ON(!PageUptodate(page));
 		create_empty_buffers(page, blocksize,
 				(1 << BH_Uptodate) | (1 << BH_Dirty));
+		if (unlikely(!page_has_buffers(page))) {
+			ntfs_warning(vol->sb, "Error allocating page "
+					"buffers.  Redirtying page so we try "
+					"again later.");
+			/*
+			 * Put the page back on mapping->dirty_pages, but leave
+			 * its buffers' dirty state as-is.
+			 */
+			redirty_page_for_writepage(wbc, page);
+			unlock_page(page);
+			return 0;
+		}
 	}
 	bh = head = page_buffers(page);
-	if (unlikely(!bh)) {
-		ntfs_warning(vol->sb, "Error allocating page buffers. "
-				"Redirtying page so we try again later.");
-		/*
-		 * Put the page back on mapping->dirty_pages, but leave its
-		 * buffer's dirty state as-is.
-		 */
-		redirty_page_for_writepage(wbc, page);
-		unlock_page(page);
-		return 0;
-	}
+	BUG_ON(!bh);
 
 	/* NOTE: Different naming scheme to ntfs_read_block()! */
 
@@ -670,6 +738,27 @@ lock_retry_remap:
 		}
 		/* It is a hole, need to instantiate it. */
 		if (lcn == LCN_HOLE) {
+			u8 *kaddr;
+			unsigned long *bpos, *bend;
+
+			/* Check if the buffer is zero. */
+			kaddr = kmap_atomic(page, KM_USER0);
+			bpos = (unsigned long *)(kaddr + bh_offset(bh));
+			bend = (unsigned long *)((u8*)bpos + blocksize);
+			do {
+				if (unlikely(*bpos))
+					break;
+			} while (likely(++bpos < bend));
+			kunmap_atomic(kaddr, KM_USER0);
+			if (bpos == bend) {
+				/*
+				 * Buffer is zero and sparse, no need to write
+				 * it.
+				 */
+				bh->b_blocknr = -1;
+				clear_buffer_dirty(bh);
+				continue;
+			}
 			// TODO: Instantiate the hole.
 			// clear_buffer_new(bh);
 			// unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
@@ -690,20 +779,37 @@ lock_retry_remap:
 			if (likely(!err))
 				goto lock_retry_remap;
 			rl = NULL;
-			lcn = err;
 		} else if (!rl)
 			up_read(&ni->runlist.lock);
+		/*
+		 * If buffer is outside the runlist, truncate has cut it out
+		 * of the runlist.  Just clean and clear the buffer and set it
+		 * uptodate so it can get discarded by the VM.
+		 */
+		if (err == -ENOENT || lcn == LCN_ENOENT) {
+			u8 *kaddr;
+
+			bh->b_blocknr = -1;
+			clear_buffer_dirty(bh);
+			kaddr = kmap_atomic(page, KM_USER0);
+			memset(kaddr + bh_offset(bh), 0, blocksize);
+			kunmap_atomic(kaddr, KM_USER0);
+			flush_dcache_page(page);
+			set_buffer_uptodate(bh);
+			err = 0;
+			continue;
+		}
 		/* Failed to map the buffer, even after retrying. */
+		if (!err)
+			err = -EIO;
 		bh->b_blocknr = -1;
 		ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
 				"attribute type 0x%x, vcn 0x%llx, offset 0x%x "
 				"because its location on disk could not be "
-				"determined%s (error code %lli).", ni->mft_no,
+				"determined%s (error code %i).", ni->mft_no,
 				ni->type, (unsigned long long)vcn,
 				vcn_ofs, is_retry ? " even after "
-				"retrying" : "", (long long)lcn);
-		if (!err)
-			err = -EIO;
+				"retrying" : "", err);
 		break;
 	} while (block++, (bh = bh->b_this_page) != head);
 
@@ -714,7 +820,7 @@ lock_retry_remap:
 	/* For the error case, need to reset bh to the beginning. */
 	bh = head;
 
-	/* Just an optimization, so ->readpage() isn't called later. */
+	/* Just an optimization, so ->readpage() is not called later. */
 	if (unlikely(!PageUptodate(page))) {
 		int uptodate = 1;
 		do {
@@ -730,7 +836,6 @@ lock_retry_remap:
 
 	/* Setup all mapped, dirty buffers for async write i/o. */
 	do {
-		get_bh(bh);
 		if (buffer_mapped(bh) && buffer_dirty(bh)) {
 			lock_buffer(bh);
 			if (test_clear_buffer_dirty(bh)) {
@@ -768,14 +873,8 @@ lock_retry_remap:
 
 	BUG_ON(PageWriteback(page));
 	set_page_writeback(page);	/* Keeps try_to_free_buffers() away. */
-	unlock_page(page);
 
-	/*
-	 * Submit the prepared buffers for i/o. Note the page is unlocked,
-	 * and the async write i/o completion handler can end_page_writeback()
-	 * at any time after the *first* submit_bh(). So the buffers can then
-	 * disappear...
-	 */
+	/* Submit the prepared buffers for i/o. */
 	need_end_writeback = TRUE;
 	do {
 		struct buffer_head *next = bh->b_this_page;
@@ -783,9 +882,9 @@ lock_retry_remap:
 			submit_bh(WRITE, bh);
 			need_end_writeback = FALSE;
 		}
-		put_bh(bh);
 		bh = next;
 	} while (bh != head);
+	unlock_page(page);
 
 	/* If no i/o was started, need to end_page_writeback(). */
 	if (unlikely(need_end_writeback))
@@ -860,7 +959,6 @@ static int ntfs_write_mst_block(struct page *page,
 	sync = (wbc->sync_mode == WB_SYNC_ALL);
 
 	/* Make sure we have mapped buffers. */
-	BUG_ON(!page_has_buffers(page));
 	bh = head = page_buffers(page);
 	BUG_ON(!bh);
 
@@ -924,6 +1022,7 @@ static int ntfs_write_mst_block(struct page *page,
 			LCN lcn;
 			unsigned int vcn_ofs;
 
+			bh->b_bdev = vol->sb->s_bdev;
 			/* Obtain the vcn and offset of the current block. */
 			vcn = (VCN)block << bh_size_bits;
 			vcn_ofs = vcn & vol->cluster_size_mask;
@@ -1279,58 +1378,65 @@ retry_writepage:
 		ntfs_debug("Write outside i_size - truncated?");
 		return 0;
 	}
+	/*
+	 * Only $DATA attributes can be encrypted and only unnamed $DATA
+	 * attributes can be compressed.  Index root can have the flags set but
+	 * this means to create compressed/encrypted files, not that the
+	 * attribute is compressed/encrypted.  Note we need to check for
+	 * AT_INDEX_ALLOCATION since this is the type of both directory and
+	 * index inodes.
+	 */
+	if (ni->type != AT_INDEX_ALLOCATION) {
+		/* If file is encrypted, deny access, just like NT4. */
+		if (NInoEncrypted(ni)) {
+			unlock_page(page);
+			BUG_ON(ni->type != AT_DATA);
+			ntfs_debug("Denying write access to encrypted file.");
+			return -EACCES;
+		}
+		/* Compressed data streams are handled in compress.c. */
+		if (NInoNonResident(ni) && NInoCompressed(ni)) {
+			BUG_ON(ni->type != AT_DATA);
+			BUG_ON(ni->name_len);
+			// TODO: Implement and replace this with
+			// return ntfs_write_compressed_block(page);
+			unlock_page(page);
+			ntfs_error(vi->i_sb, "Writing to compressed files is "
+					"not supported yet.  Sorry.");
+			return -EOPNOTSUPP;
+		}
+		// TODO: Implement and remove this check.
+		if (NInoNonResident(ni) && NInoSparse(ni)) {
+			unlock_page(page);
+			ntfs_error(vi->i_sb, "Writing to sparse files is not "
+					"supported yet.  Sorry.");
+			return -EOPNOTSUPP;
+		}
+	}
 	/* NInoNonResident() == NInoIndexAllocPresent() */
 	if (NInoNonResident(ni)) {
-		/*
-		 * Only unnamed $DATA attributes can be compressed, encrypted,
-		 * and/or sparse.
-		 */
-		if (ni->type == AT_DATA && !ni->name_len) {
-			/* If file is encrypted, deny access, just like NT4. */
-			if (NInoEncrypted(ni)) {
-				unlock_page(page);
-				ntfs_debug("Denying write access to encrypted "
-						"file.");
-				return -EACCES;
-			}
-			/* Compressed data streams are handled in compress.c. */
-			if (NInoCompressed(ni)) {
-				// TODO: Implement and replace this check with
-				// return ntfs_write_compressed_block(page);
-				unlock_page(page);
-				ntfs_error(vi->i_sb, "Writing to compressed "
-						"files is not supported yet. "
-						"Sorry.");
-				return -EOPNOTSUPP;
-			}
-			// TODO: Implement and remove this check.
-			if (NInoSparse(ni)) {
-				unlock_page(page);
-				ntfs_error(vi->i_sb, "Writing to sparse files "
-						"is not supported yet. Sorry.");
-				return -EOPNOTSUPP;
-			}
-		}
 		/* We have to zero every time due to mmap-at-end-of-file. */
 		if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) {
 			/* The page straddles i_size. */
 			unsigned int ofs = i_size & ~PAGE_CACHE_MASK;
 			kaddr = kmap_atomic(page, KM_USER0);
 			memset(kaddr + ofs, 0, PAGE_CACHE_SIZE - ofs);
-			flush_dcache_page(page);
 			kunmap_atomic(kaddr, KM_USER0);
+			flush_dcache_page(page);
 		}
 		/* Handle mst protected attributes. */
 		if (NInoMstProtected(ni))
 			return ntfs_write_mst_block(page, wbc);
-		/* Normal data stream. */
+		/* Normal, non-resident data stream. */
 		return ntfs_write_block(page, wbc);
 	}
 	/*
-	 * Attribute is resident, implying it is not compressed, encrypted,
-	 * sparse, or mst protected.  This also means the attribute is smaller
-	 * than an mft record and hence smaller than a page, so can simply
-	 * return error on any pages with index above 0.
+	 * Attribute is resident, implying it is not compressed, encrypted, or
+	 * mst protected.  This also means the attribute is smaller than an mft
+	 * record and hence smaller than a page, so can simply return error on
+	 * any pages with index above 0.  Note the attribute can actually be
+	 * marked compressed but if it is resident the actual data is not
+	 * compressed so we are ok to ignore the compressed flag here.
 	 */
 	BUG_ON(page_has_buffers(page));
 	BUG_ON(!PageUptodate(page));
@@ -1379,50 +1485,33 @@ retry_writepage:
 	BUG_ON(PageWriteback(page));
 	set_page_writeback(page);
 	unlock_page(page);
-
-	/*
-	 * Here, we don't need to zero the out of bounds area everytime because
-	 * the below memcpy() already takes care of the mmap-at-end-of-file
-	 * requirements. If the file is converted to a non-resident one, then
-	 * the code path use is switched to the non-resident one where the
-	 * zeroing happens on each ntfs_writepage() invocation.
-	 *
-	 * The above also applies nicely when i_size is decreased.
-	 *
-	 * When i_size is increased, the memory between the old and new i_size
-	 * _must_ be zeroed (or overwritten with new data). Otherwise we will
-	 * expose data to userspace/disk which should never have been exposed.
-	 *
-	 * FIXME: Ensure that i_size increases do the zeroing/overwriting and
-	 * if we cannot guarantee that, then enable the zeroing below.  If the
-	 * zeroing below is enabled, we MUST move the unlock_page() from above
-	 * to after the kunmap_atomic(), i.e. just before the
-	 * end_page_writeback().
-	 * UPDATE: ntfs_prepare/commit_write() do the zeroing on i_size
-	 * increases for resident attributes so those are ok.
-	 * TODO: ntfs_truncate(), others?
-	 */
-
 	attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
 	i_size = i_size_read(vi);
 	if (unlikely(attr_len > i_size)) {
+		/* Race with shrinking truncate or a failed truncate. */
 		attr_len = i_size;
-		ctx->attr->data.resident.value_length = cpu_to_le32(attr_len);
+		/*
+		 * If the truncate failed, fix it up now.  If a concurrent
+		 * truncate, we do its job, so it does not have to do anything.
+		 */
+		err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr,
+				attr_len);
+		/* Shrinking cannot fail. */
+		BUG_ON(err);
 	}
 	kaddr = kmap_atomic(page, KM_USER0);
 	/* Copy the data from the page to the mft record. */
 	memcpy((u8*)ctx->attr +
 			le16_to_cpu(ctx->attr->data.resident.value_offset),
 			kaddr, attr_len);
-	flush_dcache_mft_record_page(ctx->ntfs_ino);
 	/* Zero out of bounds area in the page cache page. */
 	memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
-	flush_dcache_page(page);
 	kunmap_atomic(kaddr, KM_USER0);
-
+	flush_dcache_page(page);
+	flush_dcache_mft_record_page(ctx->ntfs_ino);
+	/* We are done with the page. */
 	end_page_writeback(page);
-
-	/* Mark the mft record dirty, so it gets written back. */
+	/* Finally, mark the mft record dirty, so it gets written back. */
 	mark_mft_record_dirty(ctx->ntfs_ino);
 	ntfs_attr_put_search_ctx(ctx);
 	unmap_mft_record(base_ni);
@@ -1452,832 +1541,6 @@ err_out:
 	return err;
 }
 
-/**
- * ntfs_prepare_nonresident_write -
- *
- */
-static int ntfs_prepare_nonresident_write(struct page *page,
-		unsigned from, unsigned to)
-{
-	VCN vcn;
-	LCN lcn;
-	s64 initialized_size;
-	loff_t i_size;
-	sector_t block, ablock, iblock;
-	struct inode *vi;
-	ntfs_inode *ni;
-	ntfs_volume *vol;
-	runlist_element *rl;
-	struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
-	unsigned long flags;
-	unsigned int vcn_ofs, block_start, block_end, blocksize;
-	int err;
-	BOOL is_retry;
-	unsigned char blocksize_bits;
-
-	vi = page->mapping->host;
-	ni = NTFS_I(vi);
-	vol = ni->vol;
-
-	ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
-			"0x%lx, from = %u, to = %u.", ni->mft_no, ni->type,
-			page->index, from, to);
-
-	BUG_ON(!NInoNonResident(ni));
-
-	blocksize_bits = vi->i_blkbits;
-	blocksize = 1 << blocksize_bits;
-
-	/*
-	 * create_empty_buffers() will create uptodate/dirty buffers if the
-	 * page is uptodate/dirty.
-	 */
-	if (!page_has_buffers(page))
-		create_empty_buffers(page, blocksize, 0);
-	bh = head = page_buffers(page);
-	if (unlikely(!bh))
-		return -ENOMEM;
-
-	/* The first block in the page. */
-	block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
-
-	read_lock_irqsave(&ni->size_lock, flags);
-	/*
-	 * The first out of bounds block for the allocated size.  No need to
-	 * round up as allocated_size is in multiples of cluster size and the
-	 * minimum cluster size is 512 bytes, which is equal to the smallest
-	 * blocksize.
-	 */
-	ablock = ni->allocated_size >> blocksize_bits;
-	i_size = i_size_read(vi);
-	initialized_size = ni->initialized_size;
-	read_unlock_irqrestore(&ni->size_lock, flags);
-
-	/* The last (fully or partially) initialized block. */
-	iblock = initialized_size >> blocksize_bits;
-
-	/* Loop through all the buffers in the page. */
-	block_start = 0;
-	rl = NULL;
-	err = 0;
-	do {
-		block_end = block_start + blocksize;
-		/*
-		 * If buffer @bh is outside the write, just mark it uptodate
-		 * if the page is uptodate and continue with the next buffer.
-		 */
-		if (block_end <= from || block_start >= to) {
-			if (PageUptodate(page)) {
-				if (!buffer_uptodate(bh))
-					set_buffer_uptodate(bh);
-			}
-			continue;
-		}
-		/*
-		 * @bh is at least partially being written to.
-		 * Make sure it is not marked as new.
-		 */
-		//if (buffer_new(bh))
-		//	clear_buffer_new(bh);
-
-		if (block >= ablock) {
-			// TODO: block is above allocated_size, need to
-			// allocate it. Best done in one go to accommodate not
-			// only block but all above blocks up to and including:
-			// ((page->index << PAGE_CACHE_SHIFT) + to + blocksize
-			// - 1) >> blobksize_bits. Obviously will need to round
-			// up to next cluster boundary, too. This should be
-			// done with a helper function, so it can be reused.
-			ntfs_error(vol->sb, "Writing beyond allocated size "
-					"is not supported yet. Sorry.");
-			err = -EOPNOTSUPP;
-			goto err_out;
-			// Need to update ablock.
-			// Need to set_buffer_new() on all block bhs that are
-			// newly allocated.
-		}
-		/*
-		 * Now we have enough allocated size to fulfill the whole
-		 * request, i.e. block < ablock is true.
-		 */
-		if (unlikely((block >= iblock) &&
-				(initialized_size < i_size))) {
-			/*
-			 * If this page is fully outside initialized size, zero
-			 * out all pages between the current initialized size
-			 * and the current page. Just use ntfs_readpage() to do
-			 * the zeroing transparently.
-			 */
-			if (block > iblock) {
-				// TODO:
-				// For each page do:
-				// - read_cache_page()
-				// Again for each page do:
-				// - wait_on_page_locked()
-				// - Check (PageUptodate(page) &&
-				//			!PageError(page))
-				// Update initialized size in the attribute and
-				// in the inode.
-				// Again, for each page do:
-				//	__set_page_dirty_buffers();
-				// page_cache_release()
-				// We don't need to wait on the writes.
-				// Update iblock.
-			}
-			/*
-			 * The current page straddles initialized size. Zero
-			 * all non-uptodate buffers and set them uptodate (and
-			 * dirty?). Note, there aren't any non-uptodate buffers
-			 * if the page is uptodate.
-			 * FIXME: For an uptodate page, the buffers may need to
-			 * be written out because they were not initialized on
-			 * disk before.
-			 */
-			if (!PageUptodate(page)) {
-				// TODO:
-				// Zero any non-uptodate buffers up to i_size.
-				// Set them uptodate and dirty.
-			}
-			// TODO:
-			// Update initialized size in the attribute and in the
-			// inode (up to i_size).
-			// Update iblock.
-			// FIXME: This is inefficient. Try to batch the two
-			// size changes to happen in one go.
-			ntfs_error(vol->sb, "Writing beyond initialized size "
-					"is not supported yet. Sorry.");
-			err = -EOPNOTSUPP;
-			goto err_out;
-			// Do NOT set_buffer_new() BUT DO clear buffer range
-			// outside write request range.
-			// set_buffer_uptodate() on complete buffers as well as
-			// set_buffer_dirty().
-		}
-
-		/* Need to map unmapped buffers. */
-		if (!buffer_mapped(bh)) {
-			/* Unmapped buffer. Need to map it. */
-			bh->b_bdev = vol->sb->s_bdev;
-
-			/* Convert block into corresponding vcn and offset. */
-			vcn = (VCN)block << blocksize_bits >>
-					vol->cluster_size_bits;
-			vcn_ofs = ((VCN)block << blocksize_bits) &
-					vol->cluster_size_mask;
-
-			is_retry = FALSE;
-			if (!rl) {
-lock_retry_remap:
-				down_read(&ni->runlist.lock);
-				rl = ni->runlist.rl;
-			}
-			if (likely(rl != NULL)) {
-				/* Seek to element containing target vcn. */
-				while (rl->length && rl[1].vcn <= vcn)
-					rl++;
-				lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
-			} else
-				lcn = LCN_RL_NOT_MAPPED;
-			if (unlikely(lcn < 0)) {
-				/*
-				 * We extended the attribute allocation above.
-				 * If we hit an ENOENT here it means that the
-				 * allocation was insufficient which is a bug.
-				 */
-				BUG_ON(lcn == LCN_ENOENT);
-
-				/* It is a hole, need to instantiate it. */
-				if (lcn == LCN_HOLE) {
-					// TODO: Instantiate the hole.
-					// clear_buffer_new(bh);
-					// unmap_underlying_metadata(bh->b_bdev,
-					//		bh->b_blocknr);
-					// For non-uptodate buffers, need to
-					// zero out the region outside the
-					// request in this bh or all bhs,
-					// depending on what we implemented
-					// above.
-					// Need to flush_dcache_page().
-					// Or could use set_buffer_new()
-					// instead?
-					ntfs_error(vol->sb, "Writing into "
-							"sparse regions is "
-							"not supported yet. "
-							"Sorry.");
-					err = -EOPNOTSUPP;
-					if (!rl)
-						up_read(&ni->runlist.lock);
-					goto err_out;
-				} else if (!is_retry &&
-						lcn == LCN_RL_NOT_MAPPED) {
-					is_retry = TRUE;
-					/*
-					 * Attempt to map runlist, dropping
-					 * lock for the duration.
-					 */
-					up_read(&ni->runlist.lock);
-					err = ntfs_map_runlist(ni, vcn);
-					if (likely(!err))
-						goto lock_retry_remap;
-					rl = NULL;
-					lcn = err;
-				} else if (!rl)
-					up_read(&ni->runlist.lock);
-				/*
-				 * Failed to map the buffer, even after
-				 * retrying.
-				 */
-				bh->b_blocknr = -1;
-				ntfs_error(vol->sb, "Failed to write to inode "
-						"0x%lx, attribute type 0x%x, "
-						"vcn 0x%llx, offset 0x%x "
-						"because its location on disk "
-						"could not be determined%s "
-						"(error code %lli).",
-						ni->mft_no, ni->type,
-						(unsigned long long)vcn,
-						vcn_ofs, is_retry ? " even "
-						"after retrying" : "",
-						(long long)lcn);
-				if (!err)
-					err = -EIO;
-				goto err_out;
-			}
-			/* We now have a successful remap, i.e. lcn >= 0. */
-
-			/* Setup buffer head to correct block. */
-			bh->b_blocknr = ((lcn << vol->cluster_size_bits)
-					+ vcn_ofs) >> blocksize_bits;
-			set_buffer_mapped(bh);
-
-			// FIXME: Something analogous to this is needed for
-			// each newly allocated block, i.e. BH_New.
-			// FIXME: Might need to take this out of the
-			// if (!buffer_mapped(bh)) {}, depending on how we
-			// implement things during the allocated_size and
-			// initialized_size extension code above.
-			if (buffer_new(bh)) {
-				clear_buffer_new(bh);
-				unmap_underlying_metadata(bh->b_bdev,
-						bh->b_blocknr);
-				if (PageUptodate(page)) {
-					set_buffer_uptodate(bh);
-					continue;
-				}
-				/*
-				 * Page is _not_ uptodate, zero surrounding
-				 * region. NOTE: This is how we decide if to
-				 * zero or not!
-				 */
-				if (block_end > to || block_start < from) {
-					void *kaddr;
-
-					kaddr = kmap_atomic(page, KM_USER0);
-					if (block_end > to)
-						memset(kaddr + to, 0,
-								block_end - to);
-					if (block_start < from)
-						memset(kaddr + block_start, 0,
-								from -
-								block_start);
-					flush_dcache_page(page);
-					kunmap_atomic(kaddr, KM_USER0);
-				}
-				continue;
-			}
-		}
-		/* @bh is mapped, set it uptodate if the page is uptodate. */
-		if (PageUptodate(page)) {
-			if (!buffer_uptodate(bh))
-				set_buffer_uptodate(bh);
-			continue;
-		}
-		/*
-		 * The page is not uptodate. The buffer is mapped. If it is not
-		 * uptodate, and it is only partially being written to, we need
-		 * to read the buffer in before the write, i.e. right now.
-		 */
-		if (!buffer_uptodate(bh) &&
-				(block_start < from || block_end > to)) {
-			ll_rw_block(READ, 1, &bh);
-			*wait_bh++ = bh;
-		}
-	} while (block++, block_start = block_end,
-			(bh = bh->b_this_page) != head);
-
-	/* Release the lock if we took it. */
-	if (rl) {
-		up_read(&ni->runlist.lock);
-		rl = NULL;
-	}
-
-	/* If we issued read requests, let them complete. */
-	while (wait_bh > wait) {
-		wait_on_buffer(*--wait_bh);
-		if (!buffer_uptodate(*wait_bh))
-			return -EIO;
-	}
-
-	ntfs_debug("Done.");
-	return 0;
-err_out:
-	/*
-	 * Zero out any newly allocated blocks to avoid exposing stale data.
-	 * If BH_New is set, we know that the block was newly allocated in the
-	 * above loop.
-	 * FIXME: What about initialized_size increments? Have we done all the
-	 * required zeroing above? If not this error handling is broken, and
-	 * in particular the if (block_end <= from) check is completely bogus.
-	 */
-	bh = head;
-	block_start = 0;
-	is_retry = FALSE;
-	do {
-		block_end = block_start + blocksize;
-		if (block_end <= from)
-			continue;
-		if (block_start >= to)
-			break;
-		if (buffer_new(bh)) {
-			void *kaddr;
-
-			clear_buffer_new(bh);
-			kaddr = kmap_atomic(page, KM_USER0);
-			memset(kaddr + block_start, 0, bh->b_size);
-			kunmap_atomic(kaddr, KM_USER0);
-			set_buffer_uptodate(bh);
-			mark_buffer_dirty(bh);
-			is_retry = TRUE;
-		}
-	} while (block_start = block_end, (bh = bh->b_this_page) != head);
-	if (is_retry)
-		flush_dcache_page(page);
-	if (rl)
-		up_read(&ni->runlist.lock);
-	return err;
-}
-
-/**
- * ntfs_prepare_write - prepare a page for receiving data
- *
- * This is called from generic_file_write() with i_sem held on the inode
- * (@page->mapping->host).  The @page is locked but not kmap()ped.  The source
- * data has not yet been copied into the @page.
- *
- * Need to extend the attribute/fill in holes if necessary, create blocks and
- * make partially overwritten blocks uptodate,
- *
- * i_size is not to be modified yet.
- *
- * Return 0 on success or -errno on error.
- *
- * Should be using block_prepare_write() [support for sparse files] or
- * cont_prepare_write() [no support for sparse files].  Cannot do that due to
- * ntfs specifics but can look at them for implementation guidance.
- *
- * Note: In the range, @from is inclusive and @to is exclusive, i.e. @from is
- * the first byte in the page that will be written to and @to is the first byte
- * after the last byte that will be written to.
- */
-static int ntfs_prepare_write(struct file *file, struct page *page,
-		unsigned from, unsigned to)
-{
-	s64 new_size;
-	loff_t i_size;
-	struct inode *vi = page->mapping->host;
-	ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
-	ntfs_volume *vol = ni->vol;
-	ntfs_attr_search_ctx *ctx = NULL;
-	MFT_RECORD *m = NULL;
-	ATTR_RECORD *a;
-	u8 *kaddr;
-	u32 attr_len;
-	int err;
-
-	ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
-			"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
-			page->index, from, to);
-	BUG_ON(!PageLocked(page));
-	BUG_ON(from > PAGE_CACHE_SIZE);
-	BUG_ON(to > PAGE_CACHE_SIZE);
-	BUG_ON(from > to);
-	BUG_ON(NInoMstProtected(ni));
-	/*
-	 * If a previous ntfs_truncate() failed, repeat it and abort if it
-	 * fails again.
-	 */
-	if (unlikely(NInoTruncateFailed(ni))) {
-		down_write(&vi->i_alloc_sem);
-		err = ntfs_truncate(vi);
-		up_write(&vi->i_alloc_sem);
-		if (err || NInoTruncateFailed(ni)) {
-			if (!err)
-				err = -EIO;
-			goto err_out;
-		}
-	}
-	/* If the attribute is not resident, deal with it elsewhere. */
-	if (NInoNonResident(ni)) {
-		/*
-		 * Only unnamed $DATA attributes can be compressed, encrypted,
-		 * and/or sparse.
-		 */
-		if (ni->type == AT_DATA && !ni->name_len) {
-			/* If file is encrypted, deny access, just like NT4. */
-			if (NInoEncrypted(ni)) {
-				ntfs_debug("Denying write access to encrypted "
-						"file.");
-				return -EACCES;
-			}
-			/* Compressed data streams are handled in compress.c. */
-			if (NInoCompressed(ni)) {
-				// TODO: Implement and replace this check with
-				// return ntfs_write_compressed_block(page);
-				ntfs_error(vi->i_sb, "Writing to compressed "
-						"files is not supported yet. "
-						"Sorry.");
-				return -EOPNOTSUPP;
-			}
-			// TODO: Implement and remove this check.
-			if (NInoSparse(ni)) {
-				ntfs_error(vi->i_sb, "Writing to sparse files "
-						"is not supported yet. Sorry.");
-				return -EOPNOTSUPP;
-			}
-		}
-		/* Normal data stream. */
-		return ntfs_prepare_nonresident_write(page, from, to);
-	}
-	/*
-	 * Attribute is resident, implying it is not compressed, encrypted, or
-	 * sparse.
-	 */
-	BUG_ON(page_has_buffers(page));
-	new_size = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
-	/* If we do not need to resize the attribute allocation we are done. */
-	if (new_size <= i_size_read(vi))
-		goto done;
-	/* Map, pin, and lock the (base) mft record. */
-	if (!NInoAttr(ni))
-		base_ni = ni;
-	else
-		base_ni = ni->ext.base_ntfs_ino;
-	m = map_mft_record(base_ni);
-	if (IS_ERR(m)) {
-		err = PTR_ERR(m);
-		m = NULL;
-		ctx = NULL;
-		goto err_out;
-	}
-	ctx = ntfs_attr_get_search_ctx(base_ni, m);
-	if (unlikely(!ctx)) {
-		err = -ENOMEM;
-		goto err_out;
-	}
-	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
-			CASE_SENSITIVE, 0, NULL, 0, ctx);
-	if (unlikely(err)) {
-		if (err == -ENOENT)
-			err = -EIO;
-		goto err_out;
-	}
-	m = ctx->mrec;
-	a = ctx->attr;
-	/* The total length of the attribute value. */
-	attr_len = le32_to_cpu(a->data.resident.value_length);
-	/* Fix an eventual previous failure of ntfs_commit_write(). */
-	i_size = i_size_read(vi);
-	if (unlikely(attr_len > i_size)) {
-		attr_len = i_size;
-		a->data.resident.value_length = cpu_to_le32(attr_len);
-	}
-	/* If we do not need to resize the attribute allocation we are done. */
-	if (new_size <= attr_len)
-		goto done_unm;
-	/* Check if new size is allowed in $AttrDef. */
-	err = ntfs_attr_size_bounds_check(vol, ni->type, new_size);
-	if (unlikely(err)) {
-		if (err == -ERANGE) {
-			ntfs_error(vol->sb, "Write would cause the inode "
-					"0x%lx to exceed the maximum size for "
-					"its attribute type (0x%x).  Aborting "
-					"write.", vi->i_ino,
-					le32_to_cpu(ni->type));
-		} else {
-			ntfs_error(vol->sb, "Inode 0x%lx has unknown "
-					"attribute type 0x%x.  Aborting "
-					"write.", vi->i_ino,
-					le32_to_cpu(ni->type));
-			err = -EIO;
-		}
-		goto err_out2;
-	}
-	/*
-	 * Extend the attribute record to be able to store the new attribute
-	 * size.
-	 */
-	if (new_size >= vol->mft_record_size || ntfs_attr_record_resize(m, a,
-			le16_to_cpu(a->data.resident.value_offset) +
-			new_size)) {
-		/* Not enough space in the mft record. */
-		ntfs_error(vol->sb, "Not enough space in the mft record for "
-				"the resized attribute value.  This is not "
-				"supported yet.  Aborting write.");
-		err = -EOPNOTSUPP;
-		goto err_out2;
-	}
-	/*
-	 * We have enough space in the mft record to fit the write.  This
-	 * implies the attribute is smaller than the mft record and hence the
-	 * attribute must be in a single page and hence page->index must be 0.
-	 */
-	BUG_ON(page->index);
-	/*
-	 * If the beginning of the write is past the old size, enlarge the
-	 * attribute value up to the beginning of the write and fill it with
-	 * zeroes.
-	 */
-	if (from > attr_len) {
-		memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
-				attr_len, 0, from - attr_len);
-		a->data.resident.value_length = cpu_to_le32(from);
-		/* Zero the corresponding area in the page as well. */
-		if (PageUptodate(page)) {
-			kaddr = kmap_atomic(page, KM_USER0);
-			memset(kaddr + attr_len, 0, from - attr_len);
-			kunmap_atomic(kaddr, KM_USER0);
-			flush_dcache_page(page);
-		}
-	}
-	flush_dcache_mft_record_page(ctx->ntfs_ino);
-	mark_mft_record_dirty(ctx->ntfs_ino);
-done_unm:
-	ntfs_attr_put_search_ctx(ctx);
-	unmap_mft_record(base_ni);
-	/*
-	 * Because resident attributes are handled by memcpy() to/from the
-	 * corresponding MFT record, and because this form of i/o is byte
-	 * aligned rather than block aligned, there is no need to bring the
-	 * page uptodate here as in the non-resident case where we need to
-	 * bring the buffers straddled by the write uptodate before
-	 * generic_file_write() does the copying from userspace.
-	 *
-	 * We thus defer the uptodate bringing of the page region outside the
-	 * region written to to ntfs_commit_write(), which makes the code
-	 * simpler and saves one atomic kmap which is good.
-	 */
-done:
-	ntfs_debug("Done.");
-	return 0;
-err_out:
-	if (err == -ENOMEM)
-		ntfs_warning(vi->i_sb, "Error allocating memory required to "
-				"prepare the write.");
-	else {
-		ntfs_error(vi->i_sb, "Resident attribute prepare write failed "
-				"with error %i.", err);
-		NVolSetErrors(vol);
-		make_bad_inode(vi);
-	}
-err_out2:
-	if (ctx)
-		ntfs_attr_put_search_ctx(ctx);
-	if (m)
-		unmap_mft_record(base_ni);
-	return err;
-}
-
-/**
- * ntfs_commit_nonresident_write -
- *
- */
-static int ntfs_commit_nonresident_write(struct page *page,
-		unsigned from, unsigned to)
-{
-	s64 pos = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
-	struct inode *vi = page->mapping->host;
-	struct buffer_head *bh, *head;
-	unsigned int block_start, block_end, blocksize;
-	BOOL partial;
-
-	ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
-			"0x%lx, from = %u, to = %u.", vi->i_ino,
-			NTFS_I(vi)->type, page->index, from, to);
-	blocksize = 1 << vi->i_blkbits;
-
-	// FIXME: We need a whole slew of special cases in here for compressed
-	// files for example...
-	// For now, we know ntfs_prepare_write() would have failed so we can't
-	// get here in any of the cases which we have to special case, so we
-	// are just a ripped off, unrolled generic_commit_write().
-
-	bh = head = page_buffers(page);
-	block_start = 0;
-	partial = FALSE;
-	do {
-		block_end = block_start + blocksize;
-		if (block_end <= from || block_start >= to) {
-			if (!buffer_uptodate(bh))
-				partial = TRUE;
-		} else {
-			set_buffer_uptodate(bh);
-			mark_buffer_dirty(bh);
-		}
-	} while (block_start = block_end, (bh = bh->b_this_page) != head);
-	/*
-	 * If this is a partial write which happened to make all buffers
-	 * uptodate then we can optimize away a bogus ->readpage() for the next
-	 * read().  Here we 'discover' whether the page went uptodate as a
-	 * result of this (potentially partial) write.
-	 */
-	if (!partial)
-		SetPageUptodate(page);
-	/*
-	 * Not convinced about this at all.  See disparity comment above.  For
-	 * now we know ntfs_prepare_write() would have failed in the write
-	 * exceeds i_size case, so this will never trigger which is fine.
-	 */
-	if (pos > i_size_read(vi)) {
-		ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
-				"not supported yet.  Sorry.");
-		return -EOPNOTSUPP;
-		// vi->i_size = pos;
-		// mark_inode_dirty(vi);
-	}
-	ntfs_debug("Done.");
-	return 0;
-}
-
-/**
- * ntfs_commit_write - commit the received data
- *
- * This is called from generic_file_write() with i_sem held on the inode
- * (@page->mapping->host).  The @page is locked but not kmap()ped.  The source
- * data has already been copied into the @page.  ntfs_prepare_write() has been
- * called before the data copied and it returned success so we can take the
- * results of various BUG checks and some error handling for granted.
- *
- * Need to mark modified blocks dirty so they get written out later when
- * ntfs_writepage() is invoked by the VM.
- *
- * Return 0 on success or -errno on error.
- *
- * Should be using generic_commit_write().  This marks buffers uptodate and
- * dirty, sets the page uptodate if all buffers in the page are uptodate, and
- * updates i_size if the end of io is beyond i_size.  In that case, it also
- * marks the inode dirty.
- *
- * Cannot use generic_commit_write() due to ntfs specialities but can look at
- * it for implementation guidance.
- *
- * If things have gone as outlined in ntfs_prepare_write(), then we do not
- * need to do any page content modifications here at all, except in the write
- * to resident attribute case, where we need to do the uptodate bringing here
- * which we combine with the copying into the mft record which means we save
- * one atomic kmap.
- */
-static int ntfs_commit_write(struct file *file, struct page *page,
-		unsigned from, unsigned to)
-{
-	struct inode *vi = page->mapping->host;
-	ntfs_inode *base_ni, *ni = NTFS_I(vi);
-	char *kaddr, *kattr;
-	ntfs_attr_search_ctx *ctx;
-	MFT_RECORD *m;
-	ATTR_RECORD *a;
-	u32 attr_len;
-	int err;
-
-	ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
-			"0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
-			page->index, from, to);
-	/* If the attribute is not resident, deal with it elsewhere. */
-	if (NInoNonResident(ni)) {
-		/* Only unnamed $DATA attributes can be compressed/encrypted. */
-		if (ni->type == AT_DATA && !ni->name_len) {
-			/* Encrypted files need separate handling. */
-			if (NInoEncrypted(ni)) {
-				// We never get here at present!
-				BUG();
-			}
-			/* Compressed data streams are handled in compress.c. */
-			if (NInoCompressed(ni)) {
-				// TODO: Implement this!
-				// return ntfs_write_compressed_block(page);
-				// We never get here at present!
-				BUG();
-			}
-		}
-		/* Normal data stream. */
-		return ntfs_commit_nonresident_write(page, from, to);
-	}
-	/*
-	 * Attribute is resident, implying it is not compressed, encrypted, or
-	 * sparse.
-	 */
-	if (!NInoAttr(ni))
-		base_ni = ni;
-	else
-		base_ni = ni->ext.base_ntfs_ino;
-	/* Map, pin, and lock the mft record. */
-	m = map_mft_record(base_ni);
-	if (IS_ERR(m)) {
-		err = PTR_ERR(m);
-		m = NULL;
-		ctx = NULL;
-		goto err_out;
-	}
-	ctx = ntfs_attr_get_search_ctx(base_ni, m);
-	if (unlikely(!ctx)) {
-		err = -ENOMEM;
-		goto err_out;
-	}
-	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
-			CASE_SENSITIVE, 0, NULL, 0, ctx);
-	if (unlikely(err)) {
-		if (err == -ENOENT)
-			err = -EIO;
-		goto err_out;
-	}
-	a = ctx->attr;
-	/* The total length of the attribute value. */
-	attr_len = le32_to_cpu(a->data.resident.value_length);
-	BUG_ON(from > attr_len);
-	kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
-	kaddr = kmap_atomic(page, KM_USER0);
-	/* Copy the received data from the page to the mft record. */
-	memcpy(kattr + from, kaddr + from, to - from);
-	/* Update the attribute length if necessary. */
-	if (to > attr_len) {
-		attr_len = to;
-		a->data.resident.value_length = cpu_to_le32(attr_len);
-	}
-	/*
-	 * If the page is not uptodate, bring the out of bounds area(s)
-	 * uptodate by copying data from the mft record to the page.
-	 */
-	if (!PageUptodate(page)) {
-		if (from > 0)
-			memcpy(kaddr, kattr, from);
-		if (to < attr_len)
-			memcpy(kaddr + to, kattr + to, attr_len - to);
-		/* Zero the region outside the end of the attribute value. */
-		if (attr_len < PAGE_CACHE_SIZE)
-			memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
-		/*
-		 * The probability of not having done any of the above is
-		 * extremely small, so we just flush unconditionally.
-		 */
-		flush_dcache_page(page);
-		SetPageUptodate(page);
-	}
-	kunmap_atomic(kaddr, KM_USER0);
-	/* Update i_size if necessary. */
-	if (i_size_read(vi) < attr_len) {
-		unsigned long flags;
-
-		write_lock_irqsave(&ni->size_lock, flags);
-		ni->allocated_size = ni->initialized_size = attr_len;
-		i_size_write(vi, attr_len);
-		write_unlock_irqrestore(&ni->size_lock, flags);
-	}
-	/* Mark the mft record dirty, so it gets written back. */
-	flush_dcache_mft_record_page(ctx->ntfs_ino);
-	mark_mft_record_dirty(ctx->ntfs_ino);
-	ntfs_attr_put_search_ctx(ctx);
-	unmap_mft_record(base_ni);
-	ntfs_debug("Done.");
-	return 0;
-err_out:
-	if (err == -ENOMEM) {
-		ntfs_warning(vi->i_sb, "Error allocating memory required to "
-				"commit the write.");
-		if (PageUptodate(page)) {
-			ntfs_warning(vi->i_sb, "Page is uptodate, setting "
-					"dirty so the write will be retried "
-					"later on by the VM.");
-			/*
-			 * Put the page on mapping->dirty_pages, but leave its
-			 * buffers' dirty state as-is.
-			 */
-			__set_page_dirty_nobuffers(page);
-			err = 0;
-		} else
-			ntfs_error(vi->i_sb, "Page is not uptodate.  Written "
-					"data has been lost.");
-	} else {
-		ntfs_error(vi->i_sb, "Resident attribute commit write failed "
-				"with error %i.", err);
-		NVolSetErrors(ni->vol);
-		make_bad_inode(vi);
-	}
-	if (ctx)
-		ntfs_attr_put_search_ctx(ctx);
-	if (m)
-		unmap_mft_record(base_ni);
-	return err;
-}
-
 #endif	/* NTFS_RW */
 
 /**
@@ -2289,9 +1552,6 @@ struct address_space_operations ntfs_aops = {
 						   disk request queue. */
 #ifdef NTFS_RW
 	.writepage	= ntfs_writepage,	/* Write dirty page to disk. */
-	.prepare_write	= ntfs_prepare_write,	/* Prepare page and buffers
-						   ready to receive data. */
-	.commit_write	= ntfs_commit_write,	/* Commit received data. */
 #endif /* NTFS_RW */
 };
 
@@ -2356,6 +1616,7 @@ void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) {
 			buffers_to_free = bh;
 	}
 	bh = head = page_buffers(page);
+	BUG_ON(!bh);
 	do {
 		bh_ofs = bh_offset(bh);
 		if (bh_ofs + bh_size <= ofs)
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index cd0f9e740b14..eda056bac256 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -21,7 +21,9 @@
  */
 
 #include <linux/buffer_head.h>
+#include <linux/sched.h>
 #include <linux/swap.h>
+#include <linux/writeback.h>
 
 #include "attrib.h"
 #include "debug.h"
@@ -36,25 +38,60 @@
  * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode
  * @ni:		ntfs inode for which to map (part of) a runlist
  * @vcn:	map runlist part containing this vcn
+ * @ctx:	active attribute search context if present or NULL if not
  *
  * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
  *
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record.  This is needed when ntfs_map_runlist_nolock() encounters unmapped
+ * runlist fragments and allows their mapping.  If you do not have the mft
+ * record mapped, you can specify @ctx as NULL and ntfs_map_runlist_nolock()
+ * will perform the necessary mapping and unmapping.
+ *
+ * Note, ntfs_map_runlist_nolock() saves the state of @ctx on entry and
+ * restores it before returning.  Thus, @ctx will be left pointing to the same
+ * attribute on return as on entry.  However, the actual pointers in @ctx may
+ * point to different memory locations on return, so you must remember to reset
+ * any cached pointers from the @ctx, i.e. after the call to
+ * ntfs_map_runlist_nolock(), you will probably want to do:
+ *	m = ctx->mrec;
+ *	a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ *
  * Return 0 on success and -errno on error.  There is one special error code
  * which is not an error as such.  This is -ENOENT.  It means that @vcn is out
  * of bounds of the runlist.
  *
- * Locking: - The runlist must be locked for writing.
- *	    - This function modifies the runlist.
+ * Note the runlist can be NULL after this function returns if @vcn is zero and
+ * the attribute has zero allocated size, i.e. there simply is no runlist.
+ *
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ *	    returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx
+ *	    is no longer valid, i.e. you need to either call
+ *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ *	    why the mapping of the old inode failed.
+ *
+ * Locking: - The runlist described by @ni must be locked for writing on entry
+ *	      and is locked on return.  Note the runlist will be modified.
+ *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ *	      entry and it will be left unmapped on return.
+ *	    - If @ctx is not NULL, the base mft record must be mapped on entry
+ *	      and it will be left mapped on return.
  */
-int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
+int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx)
 {
 	VCN end_vcn;
+	unsigned long flags;
 	ntfs_inode *base_ni;
 	MFT_RECORD *m;
 	ATTR_RECORD *a;
-	ntfs_attr_search_ctx *ctx;
 	runlist_element *rl;
+	struct page *put_this_page = NULL;
 	int err = 0;
+	BOOL ctx_is_temporary, ctx_needs_reset;
+	ntfs_attr_search_ctx old_ctx = { NULL, };
 
 	ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
 			(unsigned long long)vcn);
@@ -62,20 +99,77 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
 		base_ni = ni;
 	else
 		base_ni = ni->ext.base_ntfs_ino;
-	m = map_mft_record(base_ni);
-	if (IS_ERR(m))
-		return PTR_ERR(m);
-	ctx = ntfs_attr_get_search_ctx(base_ni, m);
-	if (unlikely(!ctx)) {
-		err = -ENOMEM;
-		goto err_out;
+	if (!ctx) {
+		ctx_is_temporary = ctx_needs_reset = TRUE;
+		m = map_mft_record(base_ni);
+		if (IS_ERR(m))
+			return PTR_ERR(m);
+		ctx = ntfs_attr_get_search_ctx(base_ni, m);
+		if (unlikely(!ctx)) {
+			err = -ENOMEM;
+			goto err_out;
+		}
+	} else {
+		VCN allocated_size_vcn;
+
+		BUG_ON(IS_ERR(ctx->mrec));
+		a = ctx->attr;
+		BUG_ON(!a->non_resident);
+		ctx_is_temporary = FALSE;
+		end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
+		read_lock_irqsave(&ni->size_lock, flags);
+		allocated_size_vcn = ni->allocated_size >>
+				ni->vol->cluster_size_bits;
+		read_unlock_irqrestore(&ni->size_lock, flags);
+		if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
+			end_vcn = allocated_size_vcn - 1;
+		/*
+		 * If we already have the attribute extent containing @vcn in
+		 * @ctx, no need to look it up again.  We slightly cheat in
+		 * that if vcn exceeds the allocated size, we will refuse to
+		 * map the runlist below, so there is definitely no need to get
+		 * the right attribute extent.
+		 */
+		if (vcn >= allocated_size_vcn || (a->type == ni->type &&
+				a->name_length == ni->name_len &&
+				!memcmp((u8*)a + le16_to_cpu(a->name_offset),
+				ni->name, ni->name_len) &&
+				sle64_to_cpu(a->data.non_resident.lowest_vcn)
+				<= vcn && end_vcn >= vcn))
+			ctx_needs_reset = FALSE;
+		else {
+			/* Save the old search context. */
+			old_ctx = *ctx;
+			/*
+			 * If the currently mapped (extent) inode is not the
+			 * base inode we will unmap it when we reinitialize the
+			 * search context which means we need to get a
+			 * reference to the page containing the mapped mft
+			 * record so we do not accidentally drop changes to the
+			 * mft record when it has not been marked dirty yet.
+			 */
+			if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
+					old_ctx.base_ntfs_ino) {
+				put_this_page = old_ctx.ntfs_ino->page;
+				page_cache_get(put_this_page);
+			}
+			/*
+			 * Reinitialize the search context so we can lookup the
+			 * needed attribute extent.
+			 */
+			ntfs_attr_reinit_search_ctx(ctx);
+			ctx_needs_reset = TRUE;
+		}
 	}
-	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
-			CASE_SENSITIVE, vcn, NULL, 0, ctx);
-	if (unlikely(err)) {
-		if (err == -ENOENT)
-			err = -EIO;
-		goto err_out;
+	if (ctx_needs_reset) {
+		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+				CASE_SENSITIVE, vcn, NULL, 0, ctx);
+		if (unlikely(err)) {
+			if (err == -ENOENT)
+				err = -EIO;
+			goto err_out;
+		}
+		BUG_ON(!ctx->attr->non_resident);
 	}
 	a = ctx->attr;
 	/*
@@ -85,8 +179,9 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
 	 * ntfs_mapping_pairs_decompress() fails.
 	 */
 	end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
-	if (unlikely(!a->data.non_resident.lowest_vcn && end_vcn <= 1))
-		end_vcn = ni->allocated_size >> ni->vol->cluster_size_bits;
+	if (!a->data.non_resident.lowest_vcn && end_vcn == 1)
+		end_vcn = sle64_to_cpu(a->data.non_resident.allocated_size) >>
+				ni->vol->cluster_size_bits;
 	if (unlikely(vcn >= end_vcn)) {
 		err = -ENOENT;
 		goto err_out;
@@ -97,9 +192,93 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
 	else
 		ni->runlist.rl = rl;
 err_out:
-	if (likely(ctx))
-		ntfs_attr_put_search_ctx(ctx);
-	unmap_mft_record(base_ni);
+	if (ctx_is_temporary) {
+		if (likely(ctx))
+			ntfs_attr_put_search_ctx(ctx);
+		unmap_mft_record(base_ni);
+	} else if (ctx_needs_reset) {
+		/*
+		 * If there is no attribute list, restoring the search context
+		 * is acomplished simply by copying the saved context back over
+		 * the caller supplied context.  If there is an attribute list,
+		 * things are more complicated as we need to deal with mapping
+		 * of mft records and resulting potential changes in pointers.
+		 */
+		if (NInoAttrList(base_ni)) {
+			/*
+			 * If the currently mapped (extent) inode is not the
+			 * one we had before, we need to unmap it and map the
+			 * old one.
+			 */
+			if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
+				/*
+				 * If the currently mapped inode is not the
+				 * base inode, unmap it.
+				 */
+				if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
+						ctx->base_ntfs_ino) {
+					unmap_extent_mft_record(ctx->ntfs_ino);
+					ctx->mrec = ctx->base_mrec;
+					BUG_ON(!ctx->mrec);
+				}
+				/*
+				 * If the old mapped inode is not the base
+				 * inode, map it.
+				 */
+				if (old_ctx.base_ntfs_ino &&
+						old_ctx.ntfs_ino !=
+						old_ctx.base_ntfs_ino) {
+retry_map:
+					ctx->mrec = map_mft_record(
+							old_ctx.ntfs_ino);
+					/*
+					 * Something bad has happened.  If out
+					 * of memory retry till it succeeds.
+					 * Any other errors are fatal and we
+					 * return the error code in ctx->mrec.
+					 * Let the caller deal with it...  We
+					 * just need to fudge things so the
+					 * caller can reinit and/or put the
+					 * search context safely.
+					 */
+					if (IS_ERR(ctx->mrec)) {
+						if (PTR_ERR(ctx->mrec) ==
+								-ENOMEM) {
+							schedule();
+							goto retry_map;
+						} else
+							old_ctx.ntfs_ino =
+								old_ctx.
+								base_ntfs_ino;
+					}
+				}
+			}
+			/* Update the changed pointers in the saved context. */
+			if (ctx->mrec != old_ctx.mrec) {
+				if (!IS_ERR(ctx->mrec))
+					old_ctx.attr = (ATTR_RECORD*)(
+							(u8*)ctx->mrec +
+							((u8*)old_ctx.attr -
+							(u8*)old_ctx.mrec));
+				old_ctx.mrec = ctx->mrec;
+			}
+		}
+		/* Restore the search context to the saved one. */
+		*ctx = old_ctx;
+		/*
+		 * We drop the reference on the page we took earlier.  In the
+		 * case that IS_ERR(ctx->mrec) is true this means we might lose
+		 * some changes to the mft record that had been made between
+		 * the last time it was marked dirty/written out and now.  This
+		 * at this stage is not a problem as the mapping error is fatal
+		 * enough that the mft record cannot be written out anyway and
+		 * the caller is very likely to shutdown the whole inode
+		 * immediately and mark the volume dirty for chkdsk to pick up
+		 * the pieces anyway.
+		 */
+		if (put_this_page)
+			page_cache_release(put_this_page);
+	}
 	return err;
 }
 
@@ -115,8 +294,8 @@ err_out:
  * of bounds of the runlist.
  *
  * Locking: - The runlist must be unlocked on entry and is unlocked on return.
- *	    - This function takes the runlist lock for writing and modifies the
- *	      runlist.
+ *	    - This function takes the runlist lock for writing and may modify
+ *	      the runlist.
  */
 int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
 {
@@ -126,7 +305,7 @@ int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
 	/* Make sure someone else didn't do the work while we were sleeping. */
 	if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <=
 			LCN_RL_NOT_MAPPED))
-		err = ntfs_map_runlist_nolock(ni, vcn);
+		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
 	up_write(&ni->runlist.lock);
 	return err;
 }
@@ -165,6 +344,7 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
 		const BOOL write_locked)
 {
 	LCN lcn;
+	unsigned long flags;
 	BOOL is_retry = FALSE;
 
 	ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.",
@@ -173,6 +353,14 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
 	BUG_ON(!ni);
 	BUG_ON(!NInoNonResident(ni));
 	BUG_ON(vcn < 0);
+	if (!ni->runlist.rl) {
+		read_lock_irqsave(&ni->size_lock, flags);
+		if (!ni->allocated_size) {
+			read_unlock_irqrestore(&ni->size_lock, flags);
+			return LCN_ENOENT;
+		}
+		read_unlock_irqrestore(&ni->size_lock, flags);
+	}
 retry_remap:
 	/* Convert vcn to lcn.  If that fails map the runlist and retry once. */
 	lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn);
@@ -196,7 +384,7 @@ retry_remap:
 				goto retry_remap;
 			}
 		}
-		err = ntfs_map_runlist_nolock(ni, vcn);
+		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
 		if (!write_locked) {
 			up_write(&ni->runlist.lock);
 			down_read(&ni->runlist.lock);
@@ -220,9 +408,9 @@ retry_remap:
 
 /**
  * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode
- * @ni:			ntfs inode describing the runlist to search
- * @vcn:		vcn to find
- * @write_locked:	true if the runlist is locked for writing
+ * @ni:		ntfs inode describing the runlist to search
+ * @vcn:	vcn to find
+ * @ctx:	active attribute search context if present or NULL if not
  *
  * Find the virtual cluster number @vcn in the runlist described by the ntfs
  * inode @ni and return the address of the runlist element containing the @vcn.
@@ -230,9 +418,22 @@ retry_remap:
  * If the @vcn is not mapped yet, the attempt is made to map the attribute
  * extent containing the @vcn and the vcn to lcn conversion is retried.
  *
- * If @write_locked is true the caller has locked the runlist for writing and
- * if false for reading.
- *
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record.  This is needed when ntfs_attr_find_vcn_nolock() encounters unmapped
+ * runlist fragments and allows their mapping.  If you do not have the mft
+ * record mapped, you can specify @ctx as NULL and ntfs_attr_find_vcn_nolock()
+ * will perform the necessary mapping and unmapping.
+ *
+ * Note, ntfs_attr_find_vcn_nolock() saves the state of @ctx on entry and
+ * restores it before returning.  Thus, @ctx will be left pointing to the same
+ * attribute on return as on entry.  However, the actual pointers in @ctx may
+ * point to different memory locations on return, so you must remember to reset
+ * any cached pointers from the @ctx, i.e. after the call to
+ * ntfs_attr_find_vcn_nolock(), you will probably want to do:
+ *	m = ctx->mrec;
+ *	a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
  * Note you need to distinguish between the lcn of the returned runlist element
  * being >= 0 and LCN_HOLE.  In the later case you have to return zeroes on
  * read and allocate clusters on write.
@@ -247,24 +448,42 @@ retry_remap:
  *	-ENOMEM - Not enough memory to map runlist.
  *	-EIO	- Critical error (runlist/file is corrupt, i/o error, etc).
  *
- * Locking: - The runlist must be locked on entry and is left locked on return.
- *	    - If @write_locked is FALSE, i.e. the runlist is locked for reading,
- *	      the lock may be dropped inside the function so you cannot rely on
- *	      the runlist still being the same when this function returns.
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ *	    returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx
+ *	    is no longer valid, i.e. you need to either call
+ *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ *	    why the mapping of the old inode failed.
+ *
+ * Locking: - The runlist described by @ni must be locked for writing on entry
+ *	      and is locked on return.  Note the runlist may be modified when
+ *	      needed runlist fragments need to be mapped.
+ *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ *	      entry and it will be left unmapped on return.
+ *	    - If @ctx is not NULL, the base mft record must be mapped on entry
+ *	      and it will be left mapped on return.
  */
 runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
-		const BOOL write_locked)
+		ntfs_attr_search_ctx *ctx)
 {
+	unsigned long flags;
 	runlist_element *rl;
 	int err = 0;
 	BOOL is_retry = FALSE;
 
-	ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.",
-			ni->mft_no, (unsigned long long)vcn,
-			write_locked ? "write" : "read");
+	ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, with%s ctx.",
+			ni->mft_no, (unsigned long long)vcn, ctx ? "" : "out");
 	BUG_ON(!ni);
 	BUG_ON(!NInoNonResident(ni));
 	BUG_ON(vcn < 0);
+	if (!ni->runlist.rl) {
+		read_lock_irqsave(&ni->size_lock, flags);
+		if (!ni->allocated_size) {
+			read_unlock_irqrestore(&ni->size_lock, flags);
+			return ERR_PTR(-ENOENT);
+		}
+		read_unlock_irqrestore(&ni->size_lock, flags);
+	}
 retry_remap:
 	rl = ni->runlist.rl;
 	if (likely(rl && vcn >= rl[0].vcn)) {
@@ -287,33 +506,22 @@ retry_remap:
 	}
 	if (!err && !is_retry) {
 		/*
-		 * The @vcn is in an unmapped region, map the runlist and
-		 * retry.
+		 * If the search context is invalid we cannot map the unmapped
+		 * region.
 		 */
-		if (!write_locked) {
-			up_read(&ni->runlist.lock);
-			down_write(&ni->runlist.lock);
-			if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) !=
-					LCN_RL_NOT_MAPPED)) {
-				up_write(&ni->runlist.lock);
-				down_read(&ni->runlist.lock);
+		if (IS_ERR(ctx->mrec))
+			err = PTR_ERR(ctx->mrec);
+		else {
+			/*
+			 * The @vcn is in an unmapped region, map the runlist
+			 * and retry.
+			 */
+			err = ntfs_map_runlist_nolock(ni, vcn, ctx);
+			if (likely(!err)) {
+				is_retry = TRUE;
 				goto retry_remap;
 			}
 		}
-		err = ntfs_map_runlist_nolock(ni, vcn);
-		if (!write_locked) {
-			up_write(&ni->runlist.lock);
-			down_read(&ni->runlist.lock);
-		}
-		if (likely(!err)) {
-			is_retry = TRUE;
-			goto retry_remap;
-		}
-		/*
-		 * -EINVAL coming from a failed mapping attempt is equivalent
-		 * to i/o error for us as it should not happen in our code
-		 * paths.
-		 */
 		if (err == -EINVAL)
 			err = -EIO;
 	} else if (!err)
@@ -528,6 +736,11 @@ int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start,
 	block_size_bits = sb->s_blocksize_bits;
 	down_read(&runlist->lock);
 	rl = runlist->rl;
+	if (!rl) {
+		ntfs_error(sb, "Cannot read attribute list since runlist is "
+				"missing.");
+		goto err_out;	
+	}
 	/* Read all clusters specified by the runlist one run at a time. */
 	while (rl->length) {
 		lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn);
@@ -981,6 +1194,7 @@ int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
 	ntfs_inode *base_ni;
 
 	ntfs_debug("Entering.");
+	BUG_ON(IS_ERR(ctx->mrec));
 	if (ctx->base_ntfs_ino)
 		base_ni = ctx->base_ntfs_ino;
 	else
@@ -1197,7 +1411,7 @@ int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type)
  */
 int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type)
 {
-	if (type == AT_INDEX_ALLOCATION || type == AT_EA)
+	if (type == AT_INDEX_ALLOCATION)
 		return -EPERM;
 	return 0;
 }
@@ -1247,12 +1461,59 @@ int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
 }
 
 /**
+ * ntfs_resident_attr_value_resize - resize the value of a resident attribute
+ * @m:		mft record containing attribute record
+ * @a:		attribute record whose value to resize
+ * @new_size:	new size in bytes to which to resize the attribute value of @a
+ *
+ * Resize the value of the attribute @a in the mft record @m to @new_size bytes.
+ * If the value is made bigger, the newly allocated space is cleared.
+ *
+ * Return 0 on success and -errno on error.  The following error codes are
+ * defined:
+ *	-ENOSPC	- Not enough space in the mft record @m to perform the resize.
+ *
+ * Note: On error, no modifications have been performed whatsoever.
+ *
+ * Warning: If you make a record smaller without having copied all the data you
+ *	    are interested in the data may be overwritten.
+ */
+int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
+		const u32 new_size)
+{
+	u32 old_size;
+
+	/* Resize the resident part of the attribute record. */
+	if (ntfs_attr_record_resize(m, a,
+			le16_to_cpu(a->data.resident.value_offset) + new_size))
+		return -ENOSPC;
+	/*
+	 * The resize succeeded!  If we made the attribute value bigger, clear
+	 * the area between the old size and @new_size.
+	 */
+	old_size = le32_to_cpu(a->data.resident.value_length);
+	if (new_size > old_size)
+		memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
+				old_size, 0, new_size - old_size);
+	/* Finally update the length of the attribute value. */
+	a->data.resident.value_length = cpu_to_le32(new_size);
+	return 0;
+}
+
+/**
  * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
  * @ni:		ntfs inode describing the attribute to convert
+ * @data_size:	size of the resident data to copy to the non-resident attribute
  *
  * Convert the resident ntfs attribute described by the ntfs inode @ni to a
  * non-resident one.
  *
+ * @data_size must be equal to the attribute value size.  This is needed since
+ * we need to know the size before we can map the mft record and our callers
+ * always know it.  The reason we cannot simply read the size from the vfs
+ * inode i_size is that this is not necessarily uptodate.  This happens when
+ * ntfs_attr_make_non_resident() is called in the ->truncate call path(s).
+ *
  * Return 0 on success and -errno on error.  The following error return codes
  * are defined:
  *	-EPERM	- The attribute is not allowed to be non-resident.
@@ -1273,7 +1534,7 @@ int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
  *
  * Locking: - The caller must hold i_sem on the inode.
  */
-int ntfs_attr_make_non_resident(ntfs_inode *ni)
+int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
 {
 	s64 new_size;
 	struct inode *vi = VFS_I(ni);
@@ -1302,14 +1563,18 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 		return err;
 	}
 	/*
+	 * FIXME: Compressed and encrypted attributes are not supported when
+	 * writing and we should never have gotten here for them.
+	 */
+	BUG_ON(NInoCompressed(ni));
+	BUG_ON(NInoEncrypted(ni));
+	/*
 	 * The size needs to be aligned to a cluster boundary for allocation
 	 * purposes.
 	 */
-	new_size = (i_size_read(vi) + vol->cluster_size - 1) &
+	new_size = (data_size + vol->cluster_size - 1) &
 			~(vol->cluster_size - 1);
 	if (new_size > 0) {
-		runlist_element *rl2;
-
 		/*
 		 * Will need the page later and since the page lock nests
 		 * outside all ntfs locks, we need to get the page now.
@@ -1320,7 +1585,7 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 			return -ENOMEM;
 		/* Start by allocating clusters to hold the attribute value. */
 		rl = ntfs_cluster_alloc(vol, 0, new_size >>
-				vol->cluster_size_bits, -1, DATA_ZONE);
+				vol->cluster_size_bits, -1, DATA_ZONE, TRUE);
 		if (IS_ERR(rl)) {
 			err = PTR_ERR(rl);
 			ntfs_debug("Failed to allocate cluster%s, error code "
@@ -1329,12 +1594,6 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 					err);
 			goto page_err_out;
 		}
-		/* Change the runlist terminator to LCN_ENOENT. */
-		rl2 = rl;
-		while (rl2->length)
-			rl2++;
-		BUG_ON(rl2->lcn != LCN_RL_NOT_MAPPED);
-		rl2->lcn = LCN_ENOENT;
 	} else {
 		rl = NULL;
 		page = NULL;
@@ -1377,10 +1636,15 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 	BUG_ON(a->non_resident);
 	/*
 	 * Calculate new offsets for the name and the mapping pairs array.
-	 * We assume the attribute is not compressed or sparse.
 	 */
-	name_ofs = (offsetof(ATTR_REC,
-			data.non_resident.compressed_size) + 7) & ~7;
+	if (NInoSparse(ni) || NInoCompressed(ni))
+		name_ofs = (offsetof(ATTR_REC,
+				data.non_resident.compressed_size) +
+				sizeof(a->data.non_resident.compressed_size) +
+				7) & ~7;
+	else
+		name_ofs = (offsetof(ATTR_REC,
+				data.non_resident.compressed_size) + 7) & ~7;
 	mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
 	/*
 	 * Determine the size of the resident part of the now non-resident
@@ -1392,7 +1656,7 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 	 * attribute value.
 	 */
 	attr_size = le32_to_cpu(a->data.resident.value_length);
-	BUG_ON(attr_size != i_size_read(vi));
+	BUG_ON(attr_size != data_size);
 	if (page && !PageUptodate(page)) {
 		kaddr = kmap_atomic(page, KM_USER0);
 		memcpy(kaddr, (u8*)a +
@@ -1419,24 +1683,23 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 		memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
 				a->name_length * sizeof(ntfschar));
 	a->name_offset = cpu_to_le16(name_ofs);
-	/*
-	 * FIXME: For now just clear all of these as we do not support them
-	 * when writing.
-	 */
-	a->flags &= cpu_to_le16(0xffff & ~le16_to_cpu(ATTR_IS_SPARSE |
-			ATTR_IS_ENCRYPTED | ATTR_COMPRESSION_MASK));
 	/* Setup the fields specific to non-resident attributes. */
 	a->data.non_resident.lowest_vcn = 0;
 	a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >>
 			vol->cluster_size_bits);
 	a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
-	a->data.non_resident.compression_unit = 0;
 	memset(&a->data.non_resident.reserved, 0,
 			sizeof(a->data.non_resident.reserved));
 	a->data.non_resident.allocated_size = cpu_to_sle64(new_size);
 	a->data.non_resident.data_size =
 			a->data.non_resident.initialized_size =
 			cpu_to_sle64(attr_size);
+	if (NInoSparse(ni) || NInoCompressed(ni)) {
+		a->data.non_resident.compression_unit = 4;
+		a->data.non_resident.compressed_size =
+				a->data.non_resident.allocated_size;
+	} else
+		a->data.non_resident.compression_unit = 0;
 	/* Generate the mapping pairs array into the attribute record. */
 	err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
 			arec_size - mp_ofs, rl, 0, -1, NULL);
@@ -1446,16 +1709,21 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni)
 		goto undo_err_out;
 	}
 	/* Setup the in-memory attribute structure to be non-resident. */
-	/*
-	 * FIXME: For now just clear all of these as we do not support them
-	 * when writing.
-	 */
-	NInoClearSparse(ni);
-	NInoClearEncrypted(ni);
-	NInoClearCompressed(ni);
 	ni->runlist.rl = rl;
 	write_lock_irqsave(&ni->size_lock, flags);
 	ni->allocated_size = new_size;
+	if (NInoSparse(ni) || NInoCompressed(ni)) {
+		ni->itype.compressed.size = ni->allocated_size;
+		ni->itype.compressed.block_size = 1U <<
+				(a->data.non_resident.compression_unit +
+				vol->cluster_size_bits);
+		ni->itype.compressed.block_size_bits =
+				ffs(ni->itype.compressed.block_size) - 1;
+		ni->itype.compressed.block_clusters = 1U <<
+				a->data.non_resident.compression_unit;
+		vi->i_blocks = ni->itype.compressed.size >> 9;
+	} else
+		vi->i_blocks = ni->allocated_size >> 9;
 	write_unlock_irqrestore(&ni->size_lock, flags);
 	/*
 	 * This needs to be last since the address space operations ->readpage
@@ -1569,6 +1837,640 @@ page_err_out:
 }
 
 /**
+ * ntfs_attr_extend_allocation - extend the allocated space of an attribute
+ * @ni:			ntfs inode of the attribute whose allocation to extend
+ * @new_alloc_size:	new size in bytes to which to extend the allocation to
+ * @new_data_size:	new size in bytes to which to extend the data to
+ * @data_start:		beginning of region which is required to be non-sparse
+ *
+ * Extend the allocated space of an attribute described by the ntfs inode @ni
+ * to @new_alloc_size bytes.  If @data_start is -1, the whole extension may be
+ * implemented as a hole in the file (as long as both the volume and the ntfs
+ * inode @ni have sparse support enabled).  If @data_start is >= 0, then the
+ * region between the old allocated size and @data_start - 1 may be made sparse
+ * but the regions between @data_start and @new_alloc_size must be backed by
+ * actual clusters.
+ *
+ * If @new_data_size is -1, it is ignored.  If it is >= 0, then the data size
+ * of the attribute is extended to @new_data_size.  Note that the i_size of the
+ * vfs inode is not updated.  Only the data size in the base attribute record
+ * is updated.  The caller has to update i_size separately if this is required.
+ * WARNING: It is a BUG() for @new_data_size to be smaller than the old data
+ * size as well as for @new_data_size to be greater than @new_alloc_size.
+ *
+ * For resident attributes this involves resizing the attribute record and if
+ * necessary moving it and/or other attributes into extent mft records and/or
+ * converting the attribute to a non-resident attribute which in turn involves
+ * extending the allocation of a non-resident attribute as described below.
+ *
+ * For non-resident attributes this involves allocating clusters in the data
+ * zone on the volume (except for regions that are being made sparse) and
+ * extending the run list to describe the allocated clusters as well as
+ * updating the mapping pairs array of the attribute.  This in turn involves
+ * resizing the attribute record and if necessary moving it and/or other
+ * attributes into extent mft records and/or splitting the attribute record
+ * into multiple extent attribute records.
+ *
+ * Also, the attribute list attribute is updated if present and in some of the
+ * above cases (the ones where extent mft records/attributes come into play),
+ * an attribute list attribute is created if not already present.
+ *
+ * Return the new allocated size on success and -errno on error.  In the case
+ * that an error is encountered but a partial extension at least up to
+ * @data_start (if present) is possible, the allocation is partially extended
+ * and this is returned.  This means the caller must check the returned size to
+ * determine if the extension was partial.  If @data_start is -1 then partial
+ * allocations are not performed.
+ *
+ * WARNING: Do not call ntfs_attr_extend_allocation() for $MFT/$DATA.
+ *
+ * Locking: This function takes the runlist lock of @ni for writing as well as
+ * locking the mft record of the base ntfs inode.  These locks are maintained
+ * throughout execution of the function.  These locks are required so that the
+ * attribute can be resized safely and so that it can for example be converted
+ * from resident to non-resident safely.
+ *
+ * TODO: At present attribute list attribute handling is not implemented.
+ *
+ * TODO: At present it is not safe to call this function for anything other
+ * than the $DATA attribute(s) of an uncompressed and unencrypted file.
+ */
+s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
+		const s64 new_data_size, const s64 data_start)
+{
+	VCN vcn;
+	s64 ll, allocated_size, start = data_start;
+	struct inode *vi = VFS_I(ni);
+	ntfs_volume *vol = ni->vol;
+	ntfs_inode *base_ni;
+	MFT_RECORD *m;
+	ATTR_RECORD *a;
+	ntfs_attr_search_ctx *ctx;
+	runlist_element *rl, *rl2;
+	unsigned long flags;
+	int err, mp_size;
+	u32 attr_len = 0; /* Silence stupid gcc warning. */
+	BOOL mp_rebuilt;
+
+#ifdef NTFS_DEBUG
+	read_lock_irqsave(&ni->size_lock, flags);
+	allocated_size = ni->allocated_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
+			"old_allocated_size 0x%llx, "
+			"new_allocated_size 0x%llx, new_data_size 0x%llx, "
+			"data_start 0x%llx.", vi->i_ino,
+			(unsigned)le32_to_cpu(ni->type),
+			(unsigned long long)allocated_size,
+			(unsigned long long)new_alloc_size,
+			(unsigned long long)new_data_size,
+			(unsigned long long)start);
+#endif
+retry_extend:
+	/*
+	 * For non-resident attributes, @start and @new_size need to be aligned
+	 * to cluster boundaries for allocation purposes.
+	 */
+	if (NInoNonResident(ni)) {
+		if (start > 0)
+			start &= ~(s64)vol->cluster_size_mask;
+		new_alloc_size = (new_alloc_size + vol->cluster_size - 1) &
+				~(s64)vol->cluster_size_mask;
+	}
+	BUG_ON(new_data_size >= 0 && new_data_size > new_alloc_size);
+	/* Check if new size is allowed in $AttrDef. */
+	err = ntfs_attr_size_bounds_check(vol, ni->type, new_alloc_size);
+	if (unlikely(err)) {
+		/* Only emit errors when the write will fail completely. */
+		read_lock_irqsave(&ni->size_lock, flags);
+		allocated_size = ni->allocated_size;
+		read_unlock_irqrestore(&ni->size_lock, flags);
+		if (start < 0 || start >= allocated_size) {
+			if (err == -ERANGE) {
+				ntfs_error(vol->sb, "Cannot extend allocation "
+						"of inode 0x%lx, attribute "
+						"type 0x%x, because the new "
+						"allocation would exceed the "
+						"maximum allowed size for "
+						"this attribute type.",
+						vi->i_ino, (unsigned)
+						le32_to_cpu(ni->type));
+			} else {
+				ntfs_error(vol->sb, "Cannot extend allocation "
+						"of inode 0x%lx, attribute "
+						"type 0x%x, because this "
+						"attribute type is not "
+						"defined on the NTFS volume.  "
+						"Possible corruption!  You "
+						"should run chkdsk!",
+						vi->i_ino, (unsigned)
+						le32_to_cpu(ni->type));
+			}
+		}
+		/* Translate error code to be POSIX conformant for write(2). */
+		if (err == -ERANGE)
+			err = -EFBIG;
+		else
+			err = -EIO;
+		return err;
+	}
+	if (!NInoAttr(ni))
+		base_ni = ni;
+	else
+		base_ni = ni->ext.base_ntfs_ino;
+	/*
+	 * We will be modifying both the runlist (if non-resident) and the mft
+	 * record so lock them both down.
+	 */
+	down_write(&ni->runlist.lock);
+	m = map_mft_record(base_ni);
+	if (IS_ERR(m)) {
+		err = PTR_ERR(m);
+		m = NULL;
+		ctx = NULL;
+		goto err_out;
+	}
+	ctx = ntfs_attr_get_search_ctx(base_ni, m);
+	if (unlikely(!ctx)) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+	read_lock_irqsave(&ni->size_lock, flags);
+	allocated_size = ni->allocated_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	/*
+	 * If non-resident, seek to the last extent.  If resident, there is
+	 * only one extent, so seek to that.
+	 */
+	vcn = NInoNonResident(ni) ? allocated_size >> vol->cluster_size_bits :
+			0;
+	/*
+	 * Abort if someone did the work whilst we waited for the locks.  If we
+	 * just converted the attribute from resident to non-resident it is
+	 * likely that exactly this has happened already.  We cannot quite
+	 * abort if we need to update the data size.
+	 */
+	if (unlikely(new_alloc_size <= allocated_size)) {
+		ntfs_debug("Allocated size already exceeds requested size.");
+		new_alloc_size = allocated_size;
+		if (new_data_size < 0)
+			goto done;
+		/*
+		 * We want the first attribute extent so that we can update the
+		 * data size.
+		 */
+		vcn = 0;
+	}
+	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+			CASE_SENSITIVE, vcn, NULL, 0, ctx);
+	if (unlikely(err)) {
+		if (err == -ENOENT)
+			err = -EIO;
+		goto err_out;
+	}
+	m = ctx->mrec;
+	a = ctx->attr;
+	/* Use goto to reduce indentation. */
+	if (a->non_resident)
+		goto do_non_resident_extend;
+	BUG_ON(NInoNonResident(ni));
+	/* The total length of the attribute value. */
+	attr_len = le32_to_cpu(a->data.resident.value_length);
+	/*
+	 * Extend the attribute record to be able to store the new attribute
+	 * size.  ntfs_attr_record_resize() will not do anything if the size is
+	 * not changing.
+	 */
+	if (new_alloc_size < vol->mft_record_size &&
+			!ntfs_attr_record_resize(m, a,
+			le16_to_cpu(a->data.resident.value_offset) +
+			new_alloc_size)) {
+		/* The resize succeeded! */
+		write_lock_irqsave(&ni->size_lock, flags);
+		ni->allocated_size = le32_to_cpu(a->length) -
+				le16_to_cpu(a->data.resident.value_offset);
+		write_unlock_irqrestore(&ni->size_lock, flags);
+		if (new_data_size >= 0) {
+			BUG_ON(new_data_size < attr_len);
+			a->data.resident.value_length =
+					cpu_to_le32((u32)new_data_size);
+		}
+		goto flush_done;
+	}
+	/*
+	 * We have to drop all the locks so we can call
+	 * ntfs_attr_make_non_resident().  This could be optimised by try-
+	 * locking the first page cache page and only if that fails dropping
+	 * the locks, locking the page, and redoing all the locking and
+	 * lookups.  While this would be a huge optimisation, it is not worth
+	 * it as this is definitely a slow code path.
+	 */
+	ntfs_attr_put_search_ctx(ctx);
+	unmap_mft_record(base_ni);
+	up_write(&ni->runlist.lock);
+	/*
+	 * Not enough space in the mft record, try to make the attribute
+	 * non-resident and if successful restart the extension process.
+	 */
+	err = ntfs_attr_make_non_resident(ni, attr_len);
+	if (likely(!err))
+		goto retry_extend;
+	/*
+	 * Could not make non-resident.  If this is due to this not being
+	 * permitted for this attribute type or there not being enough space,
+	 * try to make other attributes non-resident.  Otherwise fail.
+	 */
+	if (unlikely(err != -EPERM && err != -ENOSPC)) {
+		/* Only emit errors when the write will fail completely. */
+		read_lock_irqsave(&ni->size_lock, flags);
+		allocated_size = ni->allocated_size;
+		read_unlock_irqrestore(&ni->size_lock, flags);
+		if (start < 0 || start >= allocated_size)
+			ntfs_error(vol->sb, "Cannot extend allocation of "
+					"inode 0x%lx, attribute type 0x%x, "
+					"because the conversion from resident "
+					"to non-resident attribute failed "
+					"with error code %i.", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+		if (err != -ENOMEM)
+			err = -EIO;
+		goto conv_err_out;
+	}
+	/* TODO: Not implemented from here, abort. */
+	read_lock_irqsave(&ni->size_lock, flags);
+	allocated_size = ni->allocated_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	if (start < 0 || start >= allocated_size) {
+		if (err == -ENOSPC)
+			ntfs_error(vol->sb, "Not enough space in the mft "
+					"record/on disk for the non-resident "
+					"attribute value.  This case is not "
+					"implemented yet.");
+		else /* if (err == -EPERM) */
+			ntfs_error(vol->sb, "This attribute type may not be "
+					"non-resident.  This case is not "
+					"implemented yet.");
+	}
+	err = -EOPNOTSUPP;
+	goto conv_err_out;
+#if 0
+	// TODO: Attempt to make other attributes non-resident.
+	if (!err)
+		goto do_resident_extend;
+	/*
+	 * Both the attribute list attribute and the standard information
+	 * attribute must remain in the base inode.  Thus, if this is one of
+	 * these attributes, we have to try to move other attributes out into
+	 * extent mft records instead.
+	 */
+	if (ni->type == AT_ATTRIBUTE_LIST ||
+			ni->type == AT_STANDARD_INFORMATION) {
+		// TODO: Attempt to move other attributes into extent mft
+		// records.
+		err = -EOPNOTSUPP;
+		if (!err)
+			goto do_resident_extend;
+		goto err_out;
+	}
+	// TODO: Attempt to move this attribute to an extent mft record, but
+	// only if it is not already the only attribute in an mft record in
+	// which case there would be nothing to gain.
+	err = -EOPNOTSUPP;
+	if (!err)
+		goto do_resident_extend;
+	/* There is nothing we can do to make enough space. )-: */
+	goto err_out;
+#endif
+do_non_resident_extend:
+	BUG_ON(!NInoNonResident(ni));
+	if (new_alloc_size == allocated_size) {
+		BUG_ON(vcn);
+		goto alloc_done;
+	}
+	/*
+	 * If the data starts after the end of the old allocation, this is a
+	 * $DATA attribute and sparse attributes are enabled on the volume and
+	 * for this inode, then create a sparse region between the old
+	 * allocated size and the start of the data.  Otherwise simply proceed
+	 * with filling the whole space between the old allocated size and the
+	 * new allocated size with clusters.
+	 */
+	if ((start >= 0 && start <= allocated_size) || ni->type != AT_DATA ||
+			!NVolSparseEnabled(vol) || NInoSparseDisabled(ni))
+		goto skip_sparse;
+	// TODO: This is not implemented yet.  We just fill in with real
+	// clusters for now...
+	ntfs_debug("Inserting holes is not-implemented yet.  Falling back to "
+			"allocating real clusters instead.");
+skip_sparse:
+	rl = ni->runlist.rl;
+	if (likely(rl)) {
+		/* Seek to the end of the runlist. */
+		while (rl->length)
+			rl++;
+	}
+	/* If this attribute extent is not mapped, map it now. */
+	if (unlikely(!rl || rl->lcn == LCN_RL_NOT_MAPPED ||
+			(rl->lcn == LCN_ENOENT && rl > ni->runlist.rl &&
+			(rl-1)->lcn == LCN_RL_NOT_MAPPED))) {
+		if (!rl && !allocated_size)
+			goto first_alloc;
+		rl = ntfs_mapping_pairs_decompress(vol, a, ni->runlist.rl);
+		if (IS_ERR(rl)) {
+			err = PTR_ERR(rl);
+			if (start < 0 || start >= allocated_size)
+				ntfs_error(vol->sb, "Cannot extend allocation "
+						"of inode 0x%lx, attribute "
+						"type 0x%x, because the "
+						"mapping of a runlist "
+						"fragment failed with error "
+						"code %i.", vi->i_ino,
+						(unsigned)le32_to_cpu(ni->type),
+						err);
+			if (err != -ENOMEM)
+				err = -EIO;
+			goto err_out;
+		}
+		ni->runlist.rl = rl;
+		/* Seek to the end of the runlist. */
+		while (rl->length)
+			rl++;
+	}
+	/*
+	 * We now know the runlist of the last extent is mapped and @rl is at
+	 * the end of the runlist.  We want to begin allocating clusters
+	 * starting at the last allocated cluster to reduce fragmentation.  If
+	 * there are no valid LCNs in the attribute we let the cluster
+	 * allocator choose the starting cluster.
+	 */
+	/* If the last LCN is a hole or simillar seek back to last real LCN. */
+	while (rl->lcn < 0 && rl > ni->runlist.rl)
+		rl--;
+first_alloc:
+	// FIXME: Need to implement partial allocations so at least part of the
+	// write can be performed when start >= 0.  (Needed for POSIX write(2)
+	// conformance.)
+	rl2 = ntfs_cluster_alloc(vol, allocated_size >> vol->cluster_size_bits,
+			(new_alloc_size - allocated_size) >>
+			vol->cluster_size_bits, (rl && (rl->lcn >= 0)) ?
+			rl->lcn + rl->length : -1, DATA_ZONE, TRUE);
+	if (IS_ERR(rl2)) {
+		err = PTR_ERR(rl2);
+		if (start < 0 || start >= allocated_size)
+			ntfs_error(vol->sb, "Cannot extend allocation of "
+					"inode 0x%lx, attribute type 0x%x, "
+					"because the allocation of clusters "
+					"failed with error code %i.", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+		if (err != -ENOMEM && err != -ENOSPC)
+			err = -EIO;
+		goto err_out;
+	}
+	rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
+	if (IS_ERR(rl)) {
+		err = PTR_ERR(rl);
+		if (start < 0 || start >= allocated_size)
+			ntfs_error(vol->sb, "Cannot extend allocation of "
+					"inode 0x%lx, attribute type 0x%x, "
+					"because the runlist merge failed "
+					"with error code %i.", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+		if (err != -ENOMEM)
+			err = -EIO;
+		if (ntfs_cluster_free_from_rl(vol, rl2)) {
+			ntfs_error(vol->sb, "Failed to release allocated "
+					"cluster(s) in error code path.  Run "
+					"chkdsk to recover the lost "
+					"cluster(s).");
+			NVolSetErrors(vol);
+		}
+		ntfs_free(rl2);
+		goto err_out;
+	}
+	ni->runlist.rl = rl;
+	ntfs_debug("Allocated 0x%llx clusters.", (long long)(new_alloc_size -
+			allocated_size) >> vol->cluster_size_bits);
+	/* Find the runlist element with which the attribute extent starts. */
+	ll = sle64_to_cpu(a->data.non_resident.lowest_vcn);
+	rl2 = ntfs_rl_find_vcn_nolock(rl, ll);
+	BUG_ON(!rl2);
+	BUG_ON(!rl2->length);
+	BUG_ON(rl2->lcn < LCN_HOLE);
+	mp_rebuilt = FALSE;
+	/* Get the size for the new mapping pairs array for this extent. */
+	mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
+	if (unlikely(mp_size <= 0)) {
+		err = mp_size;
+		if (start < 0 || start >= allocated_size)
+			ntfs_error(vol->sb, "Cannot extend allocation of "
+					"inode 0x%lx, attribute type 0x%x, "
+					"because determining the size for the "
+					"mapping pairs failed with error code "
+					"%i.", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+		err = -EIO;
+		goto undo_alloc;
+	}
+	/* Extend the attribute record to fit the bigger mapping pairs array. */
+	attr_len = le32_to_cpu(a->length);
+	err = ntfs_attr_record_resize(m, a, mp_size +
+			le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
+	if (unlikely(err)) {
+		BUG_ON(err != -ENOSPC);
+		// TODO: Deal with this by moving this extent to a new mft
+		// record or by starting a new extent in a new mft record,
+		// possibly by extending this extent partially and filling it
+		// and creating a new extent for the remainder, or by making
+		// other attributes non-resident and/or by moving other
+		// attributes out of this mft record.
+		if (start < 0 || start >= allocated_size)
+			ntfs_error(vol->sb, "Not enough space in the mft "
+					"record for the extended attribute "
+					"record.  This case is not "
+					"implemented yet.");
+		err = -EOPNOTSUPP;
+		goto undo_alloc;
+	}
+	mp_rebuilt = TRUE;
+	/* Generate the mapping pairs array directly into the attr record. */
+	err = ntfs_mapping_pairs_build(vol, (u8*)a +
+			le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
+			mp_size, rl2, ll, -1, NULL);
+	if (unlikely(err)) {
+		if (start < 0 || start >= allocated_size)
+			ntfs_error(vol->sb, "Cannot extend allocation of "
+					"inode 0x%lx, attribute type 0x%x, "
+					"because building the mapping pairs "
+					"failed with error code %i.", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+		err = -EIO;
+		goto undo_alloc;
+	}
+	/* Update the highest_vcn. */
+	a->data.non_resident.highest_vcn = cpu_to_sle64((new_alloc_size >>
+			vol->cluster_size_bits) - 1);
+	/*
+	 * We now have extended the allocated size of the attribute.  Reflect
+	 * this in the ntfs_inode structure and the attribute record.
+	 */
+	if (a->data.non_resident.lowest_vcn) {
+		/*
+		 * We are not in the first attribute extent, switch to it, but
+		 * first ensure the changes will make it to disk later.
+		 */
+		flush_dcache_mft_record_page(ctx->ntfs_ino);
+		mark_mft_record_dirty(ctx->ntfs_ino);
+		ntfs_attr_reinit_search_ctx(ctx);
+		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+				CASE_SENSITIVE, 0, NULL, 0, ctx);
+		if (unlikely(err))
+			goto restore_undo_alloc;
+		/* @m is not used any more so no need to set it. */
+		a = ctx->attr;
+	}
+	write_lock_irqsave(&ni->size_lock, flags);
+	ni->allocated_size = new_alloc_size;
+	a->data.non_resident.allocated_size = cpu_to_sle64(new_alloc_size);
+	/*
+	 * FIXME: This would fail if @ni is a directory, $MFT, or an index,
+	 * since those can have sparse/compressed set.  For example can be
+	 * set compressed even though it is not compressed itself and in that
+	 * case the bit means that files are to be created compressed in the
+	 * directory...  At present this is ok as this code is only called for
+	 * regular files, and only for their $DATA attribute(s).
+	 * FIXME: The calculation is wrong if we created a hole above.  For now
+	 * it does not matter as we never create holes.
+	 */
+	if (NInoSparse(ni) || NInoCompressed(ni)) {
+		ni->itype.compressed.size += new_alloc_size - allocated_size;
+		a->data.non_resident.compressed_size =
+				cpu_to_sle64(ni->itype.compressed.size);
+		vi->i_blocks = ni->itype.compressed.size >> 9;
+	} else
+		vi->i_blocks = new_alloc_size >> 9;
+	write_unlock_irqrestore(&ni->size_lock, flags);
+alloc_done:
+	if (new_data_size >= 0) {
+		BUG_ON(new_data_size <
+				sle64_to_cpu(a->data.non_resident.data_size));
+		a->data.non_resident.data_size = cpu_to_sle64(new_data_size);
+	}
+flush_done:
+	/* Ensure the changes make it to disk. */
+	flush_dcache_mft_record_page(ctx->ntfs_ino);
+	mark_mft_record_dirty(ctx->ntfs_ino);
+done:
+	ntfs_attr_put_search_ctx(ctx);
+	unmap_mft_record(base_ni);
+	up_write(&ni->runlist.lock);
+	ntfs_debug("Done, new_allocated_size 0x%llx.",
+			(unsigned long long)new_alloc_size);
+	return new_alloc_size;
+restore_undo_alloc:
+	if (start < 0 || start >= allocated_size)
+		ntfs_error(vol->sb, "Cannot complete extension of allocation "
+				"of inode 0x%lx, attribute type 0x%x, because "
+				"lookup of first attribute extent failed with "
+				"error code %i.", vi->i_ino,
+				(unsigned)le32_to_cpu(ni->type), err);
+	if (err == -ENOENT)
+		err = -EIO;
+	ntfs_attr_reinit_search_ctx(ctx);
+	if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
+			allocated_size >> vol->cluster_size_bits, NULL, 0,
+			ctx)) {
+		ntfs_error(vol->sb, "Failed to find last attribute extent of "
+				"attribute in error code path.  Run chkdsk to "
+				"recover.");
+		write_lock_irqsave(&ni->size_lock, flags);
+		ni->allocated_size = new_alloc_size;
+		/*
+		 * FIXME: This would fail if @ni is a directory...  See above.
+		 * FIXME: The calculation is wrong if we created a hole above.
+		 * For now it does not matter as we never create holes.
+		 */
+		if (NInoSparse(ni) || NInoCompressed(ni)) {
+			ni->itype.compressed.size += new_alloc_size -
+					allocated_size;
+			vi->i_blocks = ni->itype.compressed.size >> 9;
+		} else
+			vi->i_blocks = new_alloc_size >> 9;
+		write_unlock_irqrestore(&ni->size_lock, flags);
+		ntfs_attr_put_search_ctx(ctx);
+		unmap_mft_record(base_ni);
+		up_write(&ni->runlist.lock);
+		/*
+		 * The only thing that is now wrong is the allocated size of the
+		 * base attribute extent which chkdsk should be able to fix.
+		 */
+		NVolSetErrors(vol);
+		return err;
+	}
+	ctx->attr->data.non_resident.highest_vcn = cpu_to_sle64(
+			(allocated_size >> vol->cluster_size_bits) - 1);
+undo_alloc:
+	ll = allocated_size >> vol->cluster_size_bits;
+	if (ntfs_cluster_free(ni, ll, -1, ctx) < 0) {
+		ntfs_error(vol->sb, "Failed to release allocated cluster(s) "
+				"in error code path.  Run chkdsk to recover "
+				"the lost cluster(s).");
+		NVolSetErrors(vol);
+	}
+	m = ctx->mrec;
+	a = ctx->attr;
+	/*
+	 * If the runlist truncation fails and/or the search context is no
+	 * longer valid, we cannot resize the attribute record or build the
+	 * mapping pairs array thus we mark the inode bad so that no access to
+	 * the freed clusters can happen.
+	 */
+	if (ntfs_rl_truncate_nolock(vol, &ni->runlist, ll) || IS_ERR(m)) {
+		ntfs_error(vol->sb, "Failed to %s in error code path.  Run "
+				"chkdsk to recover.", IS_ERR(m) ?
+				"restore attribute search context" :
+				"truncate attribute runlist");
+		make_bad_inode(vi);
+		make_bad_inode(VFS_I(base_ni));
+		NVolSetErrors(vol);
+	} else if (mp_rebuilt) {
+		if (ntfs_attr_record_resize(m, a, attr_len)) {
+			ntfs_error(vol->sb, "Failed to restore attribute "
+					"record in error code path.  Run "
+					"chkdsk to recover.");
+			make_bad_inode(vi);
+			make_bad_inode(VFS_I(base_ni));
+			NVolSetErrors(vol);
+		} else /* if (success) */ {
+			if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
+					a->data.non_resident.
+					mapping_pairs_offset), attr_len -
+					le16_to_cpu(a->data.non_resident.
+					mapping_pairs_offset), rl2, ll, -1,
+					NULL)) {
+				ntfs_error(vol->sb, "Failed to restore "
+						"mapping pairs array in error "
+						"code path.  Run chkdsk to "
+						"recover.");
+				make_bad_inode(vi);
+				make_bad_inode(VFS_I(base_ni));
+				NVolSetErrors(vol);
+			}
+			flush_dcache_mft_record_page(ctx->ntfs_ino);
+			mark_mft_record_dirty(ctx->ntfs_ino);
+		}
+	}
+err_out:
+	if (ctx)
+		ntfs_attr_put_search_ctx(ctx);
+	if (m)
+		unmap_mft_record(base_ni);
+	up_write(&ni->runlist.lock);
+conv_err_out:
+	ntfs_debug("Failed.  Returning error code %i.", err);
+	return err;
+}
+
+/**
  * ntfs_attr_set - fill (a part of) an attribute with a byte
  * @ni:		ntfs inode describing the attribute to fill
  * @ofs:	offset inside the attribute at which to start to fill
@@ -1603,6 +2505,12 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
 	BUG_ON(cnt < 0);
 	if (!cnt)
 		goto done;
+	/*
+	 * FIXME: Compressed and encrypted attributes are not supported when
+	 * writing and we should never have gotten here for them.
+	 */
+	BUG_ON(NInoCompressed(ni));
+	BUG_ON(NInoEncrypted(ni));
 	mapping = VFS_I(ni)->i_mapping;
 	/* Work out the starting index and page offset. */
 	idx = ofs >> PAGE_CACHE_SHIFT;
@@ -1684,6 +2592,8 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
 		/* Finally unlock and release the page. */
 		unlock_page(page);
 		page_cache_release(page);
+		balance_dirty_pages_ratelimited(mapping);
+		cond_resched();
 	}
 	/* If there is a last partial page, need to do it the slow way. */
 	if (end_ofs) {
diff --git a/fs/ntfs/attrib.h b/fs/ntfs/attrib.h
index 0e4ac6d3c0e7..9074886b44ba 100644
--- a/fs/ntfs/attrib.h
+++ b/fs/ntfs/attrib.h
@@ -60,14 +60,15 @@ typedef struct {
 	ATTR_RECORD *base_attr;
 } ntfs_attr_search_ctx;
 
-extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn);
+extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn,
+		ntfs_attr_search_ctx *ctx);
 extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn);
 
 extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
 		const BOOL write_locked);
 
 extern runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni,
-		const VCN vcn, const BOOL write_locked);
+		const VCN vcn, ntfs_attr_search_ctx *ctx);
 
 int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
 		const u32 name_len, const IGNORE_CASE_BOOL ic,
@@ -99,8 +100,13 @@ extern int ntfs_attr_can_be_resident(const ntfs_volume *vol,
 		const ATTR_TYPE type);
 
 extern int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size);
+extern int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
+		const u32 new_size);
+
+extern int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size);
 
-extern int ntfs_attr_make_non_resident(ntfs_inode *ni);
+extern s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
+		const s64 new_data_size, const s64 data_start);
 
 extern int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt,
 		const u8 val);
diff --git a/fs/ntfs/bitmap.c b/fs/ntfs/bitmap.c
index 12cf2e30c7dd..7a190cdc60e2 100644
--- a/fs/ntfs/bitmap.c
+++ b/fs/ntfs/bitmap.c
@@ -1,7 +1,7 @@
 /*
  * bitmap.c - NTFS kernel bitmap handling.  Part of the Linux-NTFS project.
  *
- * Copyright (c) 2004 Anton Altaparmakov
+ * Copyright (c) 2004-2005 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -90,7 +90,8 @@ int __ntfs_bitmap_set_bits_in_run(struct inode *vi, const s64 start_bit,
 	/* If the first byte is partial, modify the appropriate bits in it. */
 	if (bit) {
 		u8 *byte = kaddr + pos;
-		while ((bit & 7) && cnt--) {
+		while ((bit & 7) && cnt) {
+			cnt--;
 			if (value)
 				*byte |= 1 << bit++;
 			else
diff --git a/fs/ntfs/compress.c b/fs/ntfs/compress.c
index 6d265cfd49aa..25d24106f893 100644
--- a/fs/ntfs/compress.c
+++ b/fs/ntfs/compress.c
@@ -539,7 +539,6 @@ int ntfs_read_compressed_block(struct page *page)
 	if (unlikely(!pages || !bhs)) {
 		kfree(bhs);
 		kfree(pages);
-		SetPageError(page);
 		unlock_page(page);
 		ntfs_error(vol->sb, "Failed to allocate internal buffers.");
 		return -ENOMEM;
@@ -871,9 +870,6 @@ lock_retry_remap:
 			for (; prev_cur_page < cur_page; prev_cur_page++) {
 				page = pages[prev_cur_page];
 				if (page) {
-					if (prev_cur_page == xpage &&
-							!xpage_done)
-						SetPageError(page);
 					flush_dcache_page(page);
 					kunmap(page);
 					unlock_page(page);
@@ -904,8 +900,6 @@ lock_retry_remap:
 					"Terminating them with extreme "
 					"prejudice.  Inode 0x%lx, page index "
 					"0x%lx.", ni->mft_no, page->index);
-			if (cur_page == xpage && !xpage_done)
-				SetPageError(page);
 			flush_dcache_page(page);
 			kunmap(page);
 			unlock_page(page);
@@ -953,8 +947,6 @@ err_out:
 	for (i = cur_page; i < max_page; i++) {
 		page = pages[i];
 		if (page) {
-			if (i == xpage && !xpage_done)
-				SetPageError(page);
 			flush_dcache_page(page);
 			kunmap(page);
 			unlock_page(page);
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c
index 46779471c542..795c3d1930f5 100644
--- a/fs/ntfs/dir.c
+++ b/fs/ntfs/dir.c
@@ -1051,7 +1051,8 @@ static inline int ntfs_filldir(ntfs_volume *vol, loff_t fpos,
 			ie->key.file_name.file_name_length, &name,
 			NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1);
 	if (name_len <= 0) {
-		ntfs_debug("Skipping unrepresentable file.");
+		ntfs_warning(vol->sb, "Skipping unrepresentable inode 0x%llx.",
+				(long long)MREF_LE(ie->data.dir.indexed_file));
 		return 0;
 	}
 	if (ie->key.file_name.file_attributes &
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index e0f530ce6b99..727533891813 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1,7 +1,7 @@
 /*
- * file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
+ * file.c - NTFS kernel file operations.  Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2004 Anton Altaparmakov
+ * Copyright (c) 2001-2005 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -19,11 +19,24 @@
  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include <linux/pagemap.h>
 #include <linux/buffer_head.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/sched.h>
+#include <linux/swap.h>
+#include <linux/uio.h>
+#include <linux/writeback.h>
+
+#include <asm/page.h>
+#include <asm/uaccess.h>
 
+#include "attrib.h"
+#include "bitmap.h"
 #include "inode.h"
 #include "debug.h"
+#include "lcnalloc.h"
+#include "malloc.h"
+#include "mft.h"
 #include "ntfs.h"
 
 /**
@@ -56,6 +69,2185 @@ static int ntfs_file_open(struct inode *vi, struct file *filp)
 #ifdef NTFS_RW
 
 /**
+ * ntfs_attr_extend_initialized - extend the initialized size of an attribute
+ * @ni:			ntfs inode of the attribute to extend
+ * @new_init_size:	requested new initialized size in bytes
+ * @cached_page:	store any allocated but unused page here
+ * @lru_pvec:		lru-buffering pagevec of the caller
+ *
+ * Extend the initialized size of an attribute described by the ntfs inode @ni
+ * to @new_init_size bytes.  This involves zeroing any non-sparse space between
+ * the old initialized size and @new_init_size both in the page cache and on
+ * disk (if relevant complete pages are already uptodate in the page cache then
+ * these are simply marked dirty).
+ *
+ * As a side-effect, the file size (vfs inode->i_size) may be incremented as,
+ * in the resident attribute case, it is tied to the initialized size and, in
+ * the non-resident attribute case, it may not fall below the initialized size.
+ *
+ * Note that if the attribute is resident, we do not need to touch the page
+ * cache at all.  This is because if the page cache page is not uptodate we
+ * bring it uptodate later, when doing the write to the mft record since we
+ * then already have the page mapped.  And if the page is uptodate, the
+ * non-initialized region will already have been zeroed when the page was
+ * brought uptodate and the region may in fact already have been overwritten
+ * with new data via mmap() based writes, so we cannot just zero it.  And since
+ * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped
+ * is unspecified, we choose not to do zeroing and thus we do not need to touch
+ * the page at all.  For a more detailed explanation see ntfs_truncate() in
+ * fs/ntfs/inode.c.
+ *
+ * @cached_page and @lru_pvec are just optimizations for dealing with multiple
+ * pages.
+ *
+ * Return 0 on success and -errno on error.  In the case that an error is
+ * encountered it is possible that the initialized size will already have been
+ * incremented some way towards @new_init_size but it is guaranteed that if
+ * this is the case, the necessary zeroing will also have happened and that all
+ * metadata is self-consistent.
+ *
+ * Locking: i_sem on the vfs inode corrseponsind to the ntfs inode @ni must be
+ *	    held by the caller.
+ */
+static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size,
+		struct page **cached_page, struct pagevec *lru_pvec)
+{
+	s64 old_init_size;
+	loff_t old_i_size;
+	pgoff_t index, end_index;
+	unsigned long flags;
+	struct inode *vi = VFS_I(ni);
+	ntfs_inode *base_ni;
+	MFT_RECORD *m = NULL;
+	ATTR_RECORD *a;
+	ntfs_attr_search_ctx *ctx = NULL;
+	struct address_space *mapping;
+	struct page *page = NULL;
+	u8 *kattr;
+	int err;
+	u32 attr_len;
+
+	read_lock_irqsave(&ni->size_lock, flags);
+	old_init_size = ni->initialized_size;
+	old_i_size = i_size_read(vi);
+	BUG_ON(new_init_size > ni->allocated_size);
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
+			"old_initialized_size 0x%llx, "
+			"new_initialized_size 0x%llx, i_size 0x%llx.",
+			vi->i_ino, (unsigned)le32_to_cpu(ni->type),
+			(unsigned long long)old_init_size,
+			(unsigned long long)new_init_size, old_i_size);
+	if (!NInoAttr(ni))
+		base_ni = ni;
+	else
+		base_ni = ni->ext.base_ntfs_ino;
+	/* Use goto to reduce indentation and we need the label below anyway. */
+	if (NInoNonResident(ni))
+		goto do_non_resident_extend;
+	BUG_ON(old_init_size != old_i_size);
+	m = map_mft_record(base_ni);
+	if (IS_ERR(m)) {
+		err = PTR_ERR(m);
+		m = NULL;
+		goto err_out;
+	}
+	ctx = ntfs_attr_get_search_ctx(base_ni, m);
+	if (unlikely(!ctx)) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+			CASE_SENSITIVE, 0, NULL, 0, ctx);
+	if (unlikely(err)) {
+		if (err == -ENOENT)
+			err = -EIO;
+		goto err_out;
+	}
+	m = ctx->mrec;
+	a = ctx->attr;
+	BUG_ON(a->non_resident);
+	/* The total length of the attribute value. */
+	attr_len = le32_to_cpu(a->data.resident.value_length);
+	BUG_ON(old_i_size != (loff_t)attr_len);
+	/*
+	 * Do the zeroing in the mft record and update the attribute size in
+	 * the mft record.
+	 */
+	kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
+	memset(kattr + attr_len, 0, new_init_size - attr_len);
+	a->data.resident.value_length = cpu_to_le32((u32)new_init_size);
+	/* Finally, update the sizes in the vfs and ntfs inodes. */
+	write_lock_irqsave(&ni->size_lock, flags);
+	i_size_write(vi, new_init_size);
+	ni->initialized_size = new_init_size;
+	write_unlock_irqrestore(&ni->size_lock, flags);
+	goto done;
+do_non_resident_extend:
+	/*
+	 * If the new initialized size @new_init_size exceeds the current file
+	 * size (vfs inode->i_size), we need to extend the file size to the
+	 * new initialized size.
+	 */
+	if (new_init_size > old_i_size) {
+		m = map_mft_record(base_ni);
+		if (IS_ERR(m)) {
+			err = PTR_ERR(m);
+			m = NULL;
+			goto err_out;
+		}
+		ctx = ntfs_attr_get_search_ctx(base_ni, m);
+		if (unlikely(!ctx)) {
+			err = -ENOMEM;
+			goto err_out;
+		}
+		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+				CASE_SENSITIVE, 0, NULL, 0, ctx);
+		if (unlikely(err)) {
+			if (err == -ENOENT)
+				err = -EIO;
+			goto err_out;
+		}
+		m = ctx->mrec;
+		a = ctx->attr;
+		BUG_ON(!a->non_resident);
+		BUG_ON(old_i_size != (loff_t)
+				sle64_to_cpu(a->data.non_resident.data_size));
+		a->data.non_resident.data_size = cpu_to_sle64(new_init_size);
+		flush_dcache_mft_record_page(ctx->ntfs_ino);
+		mark_mft_record_dirty(ctx->ntfs_ino);
+		/* Update the file size in the vfs inode. */
+		i_size_write(vi, new_init_size);
+		ntfs_attr_put_search_ctx(ctx);
+		ctx = NULL;
+		unmap_mft_record(base_ni);
+		m = NULL;
+	}
+	mapping = vi->i_mapping;
+	index = old_init_size >> PAGE_CACHE_SHIFT;
+	end_index = (new_init_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	do {
+		/*
+		 * Read the page.  If the page is not present, this will zero
+		 * the uninitialized regions for us.
+		 */
+		page = read_cache_page(mapping, index,
+				(filler_t*)mapping->a_ops->readpage, NULL);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto init_err_out;
+		}
+		wait_on_page_locked(page);
+		if (unlikely(!PageUptodate(page) || PageError(page))) {
+			page_cache_release(page);
+			err = -EIO;
+			goto init_err_out;
+		}
+		/*
+		 * Update the initialized size in the ntfs inode.  This is
+		 * enough to make ntfs_writepage() work.
+		 */
+		write_lock_irqsave(&ni->size_lock, flags);
+		ni->initialized_size = (index + 1) << PAGE_CACHE_SHIFT;
+		if (ni->initialized_size > new_init_size)
+			ni->initialized_size = new_init_size;
+		write_unlock_irqrestore(&ni->size_lock, flags);
+		/* Set the page dirty so it gets written out. */
+		set_page_dirty(page);
+		page_cache_release(page);
+		/*
+		 * Play nice with the vm and the rest of the system.  This is
+		 * very much needed as we can potentially be modifying the
+		 * initialised size from a very small value to a really huge
+		 * value, e.g.
+		 *	f = open(somefile, O_TRUNC);
+		 *	truncate(f, 10GiB);
+		 *	seek(f, 10GiB);
+		 *	write(f, 1);
+		 * And this would mean we would be marking dirty hundreds of
+		 * thousands of pages or as in the above example more than
+		 * two and a half million pages!
+		 *
+		 * TODO: For sparse pages could optimize this workload by using
+		 * the FsMisc / MiscFs page bit as a "PageIsSparse" bit.  This
+		 * would be set in readpage for sparse pages and here we would
+		 * not need to mark dirty any pages which have this bit set.
+		 * The only caveat is that we have to clear the bit everywhere
+		 * where we allocate any clusters that lie in the page or that
+		 * contain the page.
+		 *
+		 * TODO: An even greater optimization would be for us to only
+		 * call readpage() on pages which are not in sparse regions as
+		 * determined from the runlist.  This would greatly reduce the
+		 * number of pages we read and make dirty in the case of sparse
+		 * files.
+		 */
+		balance_dirty_pages_ratelimited(mapping);
+		cond_resched();
+	} while (++index < end_index);
+	read_lock_irqsave(&ni->size_lock, flags);
+	BUG_ON(ni->initialized_size != new_init_size);
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	/* Now bring in sync the initialized_size in the mft record. */
+	m = map_mft_record(base_ni);
+	if (IS_ERR(m)) {
+		err = PTR_ERR(m);
+		m = NULL;
+		goto init_err_out;
+	}
+	ctx = ntfs_attr_get_search_ctx(base_ni, m);
+	if (unlikely(!ctx)) {
+		err = -ENOMEM;
+		goto init_err_out;
+	}
+	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+			CASE_SENSITIVE, 0, NULL, 0, ctx);
+	if (unlikely(err)) {
+		if (err == -ENOENT)
+			err = -EIO;
+		goto init_err_out;
+	}
+	m = ctx->mrec;
+	a = ctx->attr;
+	BUG_ON(!a->non_resident);
+	a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size);
+done:
+	flush_dcache_mft_record_page(ctx->ntfs_ino);
+	mark_mft_record_dirty(ctx->ntfs_ino);
+	if (ctx)
+		ntfs_attr_put_search_ctx(ctx);
+	if (m)
+		unmap_mft_record(base_ni);
+	ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.",
+			(unsigned long long)new_init_size, i_size_read(vi));
+	return 0;
+init_err_out:
+	write_lock_irqsave(&ni->size_lock, flags);
+	ni->initialized_size = old_init_size;
+	write_unlock_irqrestore(&ni->size_lock, flags);
+err_out:
+	if (ctx)
+		ntfs_attr_put_search_ctx(ctx);
+	if (m)
+		unmap_mft_record(base_ni);
+	ntfs_debug("Failed.  Returning error code %i.", err);
+	return err;
+}
+
+/**
+ * ntfs_fault_in_pages_readable -
+ *
+ * Fault a number of userspace pages into pagetables.
+ *
+ * Unlike include/linux/pagemap.h::fault_in_pages_readable(), this one copes
+ * with more than two userspace pages as well as handling the single page case
+ * elegantly.
+ *
+ * If you find this difficult to understand, then think of the while loop being
+ * the following code, except that we do without the integer variable ret:
+ *
+ *	do {
+ *		ret = __get_user(c, uaddr);
+ *		uaddr += PAGE_SIZE;
+ *	} while (!ret && uaddr < end);
+ *
+ * Note, the final __get_user() may well run out-of-bounds of the user buffer,
+ * but _not_ out-of-bounds of the page the user buffer belongs to, and since
+ * this is only a read and not a write, and since it is still in the same page,
+ * it should not matter and this makes the code much simpler.
+ */
+static inline void ntfs_fault_in_pages_readable(const char __user *uaddr,
+		int bytes)
+{
+	const char __user *end;
+	volatile char c;
+
+	/* Set @end to the first byte outside the last page we care about. */
+	end = (const char __user*)PAGE_ALIGN((ptrdiff_t __user)uaddr + bytes);
+
+	while (!__get_user(c, uaddr) && (uaddr += PAGE_SIZE, uaddr < end))
+		;
+}
+
+/**
+ * ntfs_fault_in_pages_readable_iovec -
+ *
+ * Same as ntfs_fault_in_pages_readable() but operates on an array of iovecs.
+ */
+static inline void ntfs_fault_in_pages_readable_iovec(const struct iovec *iov,
+		size_t iov_ofs, int bytes)
+{
+	do {
+		const char __user *buf;
+		unsigned len;
+
+		buf = iov->iov_base + iov_ofs;
+		len = iov->iov_len - iov_ofs;
+		if (len > bytes)
+			len = bytes;
+		ntfs_fault_in_pages_readable(buf, len);
+		bytes -= len;
+		iov++;
+		iov_ofs = 0;
+	} while (bytes);
+}
+
+/**
+ * __ntfs_grab_cache_pages - obtain a number of locked pages
+ * @mapping:	address space mapping from which to obtain page cache pages
+ * @index:	starting index in @mapping at which to begin obtaining pages
+ * @nr_pages:	number of page cache pages to obtain
+ * @pages:	array of pages in which to return the obtained page cache pages
+ * @cached_page: allocated but as yet unused page
+ * @lru_pvec:	lru-buffering pagevec of caller
+ *
+ * Obtain @nr_pages locked page cache pages from the mapping @maping and
+ * starting at index @index.
+ *
+ * If a page is newly created, increment its refcount and add it to the
+ * caller's lru-buffering pagevec @lru_pvec.
+ *
+ * This is the same as mm/filemap.c::__grab_cache_page(), except that @nr_pages
+ * are obtained at once instead of just one page and that 0 is returned on
+ * success and -errno on error.
+ *
+ * Note, the page locks are obtained in ascending page index order.
+ */
+static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
+		pgoff_t index, const unsigned nr_pages, struct page **pages,
+		struct page **cached_page, struct pagevec *lru_pvec)
+{
+	int err, nr;
+
+	BUG_ON(!nr_pages);
+	err = nr = 0;
+	do {
+		pages[nr] = find_lock_page(mapping, index);
+		if (!pages[nr]) {
+			if (!*cached_page) {
+				*cached_page = page_cache_alloc(mapping);
+				if (unlikely(!*cached_page)) {
+					err = -ENOMEM;
+					goto err_out;
+				}
+			}
+			err = add_to_page_cache(*cached_page, mapping, index,
+					GFP_KERNEL);
+			if (unlikely(err)) {
+				if (err == -EEXIST)
+					continue;
+				goto err_out;
+			}
+			pages[nr] = *cached_page;
+			page_cache_get(*cached_page);
+			if (unlikely(!pagevec_add(lru_pvec, *cached_page)))
+				__pagevec_lru_add(lru_pvec);
+			*cached_page = NULL;
+		}
+		index++;
+		nr++;
+	} while (nr < nr_pages);
+out:
+	return err;
+err_out:
+	while (nr > 0) {
+		unlock_page(pages[--nr]);
+		page_cache_release(pages[nr]);
+	}
+	goto out;
+}
+
+static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
+{
+	lock_buffer(bh);
+	get_bh(bh);
+	bh->b_end_io = end_buffer_read_sync;
+	return submit_bh(READ, bh);
+}
+
+/**
+ * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
+ * @pages:	array of destination pages
+ * @nr_pages:	number of pages in @pages
+ * @pos:	byte position in file at which the write begins
+ * @bytes:	number of bytes to be written
+ *
+ * This is called for non-resident attributes from ntfs_file_buffered_write()
+ * with i_sem held on the inode (@pages[0]->mapping->host).  There are
+ * @nr_pages pages in @pages which are locked but not kmap()ped.  The source
+ * data has not yet been copied into the @pages.
+ * 
+ * Need to fill any holes with actual clusters, allocate buffers if necessary,
+ * ensure all the buffers are mapped, and bring uptodate any buffers that are
+ * only partially being written to.
+ *
+ * If @nr_pages is greater than one, we are guaranteed that the cluster size is
+ * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside
+ * the same cluster and that they are the entirety of that cluster, and that
+ * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
+ *
+ * i_size is not to be modified yet.
+ *
+ * Return 0 on success or -errno on error.
+ */
+static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
+		unsigned nr_pages, s64 pos, size_t bytes)
+{
+	VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
+	LCN lcn;
+	s64 bh_pos, vcn_len, end, initialized_size;
+	sector_t lcn_block;
+	struct page *page;
+	struct inode *vi;
+	ntfs_inode *ni, *base_ni = NULL;
+	ntfs_volume *vol;
+	runlist_element *rl, *rl2;
+	struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
+	ntfs_attr_search_ctx *ctx = NULL;
+	MFT_RECORD *m = NULL;
+	ATTR_RECORD *a = NULL;
+	unsigned long flags;
+	u32 attr_rec_len = 0;
+	unsigned blocksize, u;
+	int err, mp_size;
+	BOOL rl_write_locked, was_hole, is_retry;
+	unsigned char blocksize_bits;
+	struct {
+		u8 runlist_merged:1;
+		u8 mft_attr_mapped:1;
+		u8 mp_rebuilt:1;
+		u8 attr_switched:1;
+	} status = { 0, 0, 0, 0 };
+
+	BUG_ON(!nr_pages);
+	BUG_ON(!pages);
+	BUG_ON(!*pages);
+	vi = pages[0]->mapping->host;
+	ni = NTFS_I(vi);
+	vol = ni->vol;
+	ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
+			"index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
+			vi->i_ino, ni->type, pages[0]->index, nr_pages,
+			(long long)pos, bytes);
+	blocksize_bits = vi->i_blkbits;
+	blocksize = 1 << blocksize_bits;
+	u = 0;
+	do {
+		struct page *page = pages[u];
+		/*
+		 * create_empty_buffers() will create uptodate/dirty buffers if
+		 * the page is uptodate/dirty.
+		 */
+		if (!page_has_buffers(page)) {
+			create_empty_buffers(page, blocksize, 0);
+			if (unlikely(!page_has_buffers(page)))
+				return -ENOMEM;
+		}
+	} while (++u < nr_pages);
+	rl_write_locked = FALSE;
+	rl = NULL;
+	err = 0;
+	vcn = lcn = -1;
+	vcn_len = 0;
+	lcn_block = -1;
+	was_hole = FALSE;
+	cpos = pos >> vol->cluster_size_bits;
+	end = pos + bytes;
+	cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
+	/*
+	 * Loop over each page and for each page over each buffer.  Use goto to
+	 * reduce indentation.
+	 */
+	u = 0;
+do_next_page:
+	page = pages[u];
+	bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
+	bh = head = page_buffers(page);
+	do {
+		VCN cdelta;
+		s64 bh_end;
+		unsigned bh_cofs;
+
+		/* Clear buffer_new on all buffers to reinitialise state. */
+		if (buffer_new(bh))
+			clear_buffer_new(bh);
+		bh_end = bh_pos + blocksize;
+		bh_cpos = bh_pos >> vol->cluster_size_bits;
+		bh_cofs = bh_pos & vol->cluster_size_mask;
+		if (buffer_mapped(bh)) {
+			/*
+			 * The buffer is already mapped.  If it is uptodate,
+			 * ignore it.
+			 */
+			if (buffer_uptodate(bh))
+				continue;
+			/*
+			 * The buffer is not uptodate.  If the page is uptodate
+			 * set the buffer uptodate and otherwise ignore it.
+			 */
+			if (PageUptodate(page)) {
+				set_buffer_uptodate(bh);
+				continue;
+			}
+			/*
+			 * Neither the page nor the buffer are uptodate.  If
+			 * the buffer is only partially being written to, we
+			 * need to read it in before the write, i.e. now.
+			 */
+			if ((bh_pos < pos && bh_end > pos) ||
+					(bh_pos < end && bh_end > end)) {
+				/*
+				 * If the buffer is fully or partially within
+				 * the initialized size, do an actual read.
+				 * Otherwise, simply zero the buffer.
+				 */
+				read_lock_irqsave(&ni->size_lock, flags);
+				initialized_size = ni->initialized_size;
+				read_unlock_irqrestore(&ni->size_lock, flags);
+				if (bh_pos < initialized_size) {
+					ntfs_submit_bh_for_read(bh);
+					*wait_bh++ = bh;
+				} else {
+					u8 *kaddr = kmap_atomic(page, KM_USER0);
+					memset(kaddr + bh_offset(bh), 0,
+							blocksize);
+					kunmap_atomic(kaddr, KM_USER0);
+					flush_dcache_page(page);
+					set_buffer_uptodate(bh);
+				}
+			}
+			continue;
+		}
+		/* Unmapped buffer.  Need to map it. */
+		bh->b_bdev = vol->sb->s_bdev;
+		/*
+		 * If the current buffer is in the same clusters as the map
+		 * cache, there is no need to check the runlist again.  The
+		 * map cache is made up of @vcn, which is the first cached file
+		 * cluster, @vcn_len which is the number of cached file
+		 * clusters, @lcn is the device cluster corresponding to @vcn,
+		 * and @lcn_block is the block number corresponding to @lcn.
+		 */
+		cdelta = bh_cpos - vcn;
+		if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
+map_buffer_cached:
+			BUG_ON(lcn < 0);
+			bh->b_blocknr = lcn_block +
+					(cdelta << (vol->cluster_size_bits -
+					blocksize_bits)) +
+					(bh_cofs >> blocksize_bits);
+			set_buffer_mapped(bh);
+			/*
+			 * If the page is uptodate so is the buffer.  If the
+			 * buffer is fully outside the write, we ignore it if
+			 * it was already allocated and we mark it dirty so it
+			 * gets written out if we allocated it.  On the other
+			 * hand, if we allocated the buffer but we are not
+			 * marking it dirty we set buffer_new so we can do
+			 * error recovery.
+			 */
+			if (PageUptodate(page)) {
+				if (!buffer_uptodate(bh))
+					set_buffer_uptodate(bh);
+				if (unlikely(was_hole)) {
+					/* We allocated the buffer. */
+					unmap_underlying_metadata(bh->b_bdev,
+							bh->b_blocknr);
+					if (bh_end <= pos || bh_pos >= end)
+						mark_buffer_dirty(bh);
+					else
+						set_buffer_new(bh);
+				}
+				continue;
+			}
+			/* Page is _not_ uptodate. */
+			if (likely(!was_hole)) {
+				/*
+				 * Buffer was already allocated.  If it is not
+				 * uptodate and is only partially being written
+				 * to, we need to read it in before the write,
+				 * i.e. now.
+				 */
+				if (!buffer_uptodate(bh) && bh_pos < end &&
+						bh_end > pos &&
+						(bh_pos < pos ||
+						bh_end > end)) {
+					/*
+					 * If the buffer is fully or partially
+					 * within the initialized size, do an
+					 * actual read.  Otherwise, simply zero
+					 * the buffer.
+					 */
+					read_lock_irqsave(&ni->size_lock,
+							flags);
+					initialized_size = ni->initialized_size;
+					read_unlock_irqrestore(&ni->size_lock,
+							flags);
+					if (bh_pos < initialized_size) {
+						ntfs_submit_bh_for_read(bh);
+						*wait_bh++ = bh;
+					} else {
+						u8 *kaddr = kmap_atomic(page,
+								KM_USER0);
+						memset(kaddr + bh_offset(bh),
+								0, blocksize);
+						kunmap_atomic(kaddr, KM_USER0);
+						flush_dcache_page(page);
+						set_buffer_uptodate(bh);
+					}
+				}
+				continue;
+			}
+			/* We allocated the buffer. */
+			unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
+			/*
+			 * If the buffer is fully outside the write, zero it,
+			 * set it uptodate, and mark it dirty so it gets
+			 * written out.  If it is partially being written to,
+			 * zero region surrounding the write but leave it to
+			 * commit write to do anything else.  Finally, if the
+			 * buffer is fully being overwritten, do nothing.
+			 */
+			if (bh_end <= pos || bh_pos >= end) {
+				if (!buffer_uptodate(bh)) {
+					u8 *kaddr = kmap_atomic(page, KM_USER0);
+					memset(kaddr + bh_offset(bh), 0,
+							blocksize);
+					kunmap_atomic(kaddr, KM_USER0);
+					flush_dcache_page(page);
+					set_buffer_uptodate(bh);
+				}
+				mark_buffer_dirty(bh);
+				continue;
+			}
+			set_buffer_new(bh);
+			if (!buffer_uptodate(bh) &&
+					(bh_pos < pos || bh_end > end)) {
+				u8 *kaddr;
+				unsigned pofs;
+					
+				kaddr = kmap_atomic(page, KM_USER0);
+				if (bh_pos < pos) {
+					pofs = bh_pos & ~PAGE_CACHE_MASK;
+					memset(kaddr + pofs, 0, pos - bh_pos);
+				}
+				if (bh_end > end) {
+					pofs = end & ~PAGE_CACHE_MASK;
+					memset(kaddr + pofs, 0, bh_end - end);
+				}
+				kunmap_atomic(kaddr, KM_USER0);
+				flush_dcache_page(page);
+			}
+			continue;
+		}
+		/*
+		 * Slow path: this is the first buffer in the cluster.  If it
+		 * is outside allocated size and is not uptodate, zero it and
+		 * set it uptodate.
+		 */
+		read_lock_irqsave(&ni->size_lock, flags);
+		initialized_size = ni->allocated_size;
+		read_unlock_irqrestore(&ni->size_lock, flags);
+		if (bh_pos > initialized_size) {
+			if (PageUptodate(page)) {
+				if (!buffer_uptodate(bh))
+					set_buffer_uptodate(bh);
+			} else if (!buffer_uptodate(bh)) {
+				u8 *kaddr = kmap_atomic(page, KM_USER0);
+				memset(kaddr + bh_offset(bh), 0, blocksize);
+				kunmap_atomic(kaddr, KM_USER0);
+				flush_dcache_page(page);
+				set_buffer_uptodate(bh);
+			}
+			continue;
+		}
+		is_retry = FALSE;
+		if (!rl) {
+			down_read(&ni->runlist.lock);
+retry_remap:
+			rl = ni->runlist.rl;
+		}
+		if (likely(rl != NULL)) {
+			/* Seek to element containing target cluster. */
+			while (rl->length && rl[1].vcn <= bh_cpos)
+				rl++;
+			lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
+			if (likely(lcn >= 0)) {
+				/*
+				 * Successful remap, setup the map cache and
+				 * use that to deal with the buffer.
+				 */
+				was_hole = FALSE;
+				vcn = bh_cpos;
+				vcn_len = rl[1].vcn - vcn;
+				lcn_block = lcn << (vol->cluster_size_bits -
+						blocksize_bits);
+				cdelta = 0;
+				/*
+				 * If the number of remaining clusters touched
+				 * by the write is smaller or equal to the
+				 * number of cached clusters, unlock the
+				 * runlist as the map cache will be used from
+				 * now on.
+				 */
+				if (likely(vcn + vcn_len >= cend)) {
+					if (rl_write_locked) {
+						up_write(&ni->runlist.lock);
+						rl_write_locked = FALSE;
+					} else
+						up_read(&ni->runlist.lock);
+					rl = NULL;
+				}
+				goto map_buffer_cached;
+			}
+		} else
+			lcn = LCN_RL_NOT_MAPPED;
+		/*
+		 * If it is not a hole and not out of bounds, the runlist is
+		 * probably unmapped so try to map it now.
+		 */
+		if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
+			if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
+				/* Attempt to map runlist. */
+				if (!rl_write_locked) {
+					/*
+					 * We need the runlist locked for
+					 * writing, so if it is locked for
+					 * reading relock it now and retry in
+					 * case it changed whilst we dropped
+					 * the lock.
+					 */
+					up_read(&ni->runlist.lock);
+					down_write(&ni->runlist.lock);
+					rl_write_locked = TRUE;
+					goto retry_remap;
+				}
+				err = ntfs_map_runlist_nolock(ni, bh_cpos,
+						NULL);
+				if (likely(!err)) {
+					is_retry = TRUE;
+					goto retry_remap;
+				}
+				/*
+				 * If @vcn is out of bounds, pretend @lcn is
+				 * LCN_ENOENT.  As long as the buffer is out
+				 * of bounds this will work fine.
+				 */
+				if (err == -ENOENT) {
+					lcn = LCN_ENOENT;
+					err = 0;
+					goto rl_not_mapped_enoent;
+				}
+			} else
+				err = -EIO;
+			/* Failed to map the buffer, even after retrying. */
+			bh->b_blocknr = -1;
+			ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
+					"attribute type 0x%x, vcn 0x%llx, "
+					"vcn offset 0x%x, because its "
+					"location on disk could not be "
+					"determined%s (error code %i).",
+					ni->mft_no, ni->type,
+					(unsigned long long)bh_cpos,
+					(unsigned)bh_pos &
+					vol->cluster_size_mask,
+					is_retry ? " even after retrying" : "",
+					err);
+			break;
+		}
+rl_not_mapped_enoent:
+		/*
+		 * The buffer is in a hole or out of bounds.  We need to fill
+		 * the hole, unless the buffer is in a cluster which is not
+		 * touched by the write, in which case we just leave the buffer
+		 * unmapped.  This can only happen when the cluster size is
+		 * less than the page cache size.
+		 */
+		if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) {
+			bh_cend = (bh_end + vol->cluster_size - 1) >>
+					vol->cluster_size_bits;
+			if ((bh_cend <= cpos || bh_cpos >= cend)) {
+				bh->b_blocknr = -1;
+				/*
+				 * If the buffer is uptodate we skip it.  If it
+				 * is not but the page is uptodate, we can set
+				 * the buffer uptodate.  If the page is not
+				 * uptodate, we can clear the buffer and set it
+				 * uptodate.  Whether this is worthwhile is
+				 * debatable and this could be removed.
+				 */
+				if (PageUptodate(page)) {
+					if (!buffer_uptodate(bh))
+						set_buffer_uptodate(bh);
+				} else if (!buffer_uptodate(bh)) {
+					u8 *kaddr = kmap_atomic(page, KM_USER0);
+					memset(kaddr + bh_offset(bh), 0,
+							blocksize);
+					kunmap_atomic(kaddr, KM_USER0);
+					flush_dcache_page(page);
+					set_buffer_uptodate(bh);
+				}
+				continue;
+			}
+		}
+		/*
+		 * Out of bounds buffer is invalid if it was not really out of
+		 * bounds.
+		 */
+		BUG_ON(lcn != LCN_HOLE);
+		/*
+		 * We need the runlist locked for writing, so if it is locked
+		 * for reading relock it now and retry in case it changed
+		 * whilst we dropped the lock.
+		 */
+		BUG_ON(!rl);
+		if (!rl_write_locked) {
+			up_read(&ni->runlist.lock);
+			down_write(&ni->runlist.lock);
+			rl_write_locked = TRUE;
+			goto retry_remap;
+		}
+		/* Find the previous last allocated cluster. */
+		BUG_ON(rl->lcn != LCN_HOLE);
+		lcn = -1;
+		rl2 = rl;
+		while (--rl2 >= ni->runlist.rl) {
+			if (rl2->lcn >= 0) {
+				lcn = rl2->lcn + rl2->length;
+				break;
+			}
+		}
+		rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
+				FALSE);
+		if (IS_ERR(rl2)) {
+			err = PTR_ERR(rl2);
+			ntfs_debug("Failed to allocate cluster, error code %i.",
+					err);
+			break;
+		}
+		lcn = rl2->lcn;
+		rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
+		if (IS_ERR(rl)) {
+			err = PTR_ERR(rl);
+			if (err != -ENOMEM)
+				err = -EIO;
+			if (ntfs_cluster_free_from_rl(vol, rl2)) {
+				ntfs_error(vol->sb, "Failed to release "
+						"allocated cluster in error "
+						"code path.  Run chkdsk to "
+						"recover the lost cluster.");
+				NVolSetErrors(vol);
+			}
+			ntfs_free(rl2);
+			break;
+		}
+		ni->runlist.rl = rl;
+		status.runlist_merged = 1;
+		ntfs_debug("Allocated cluster, lcn 0x%llx.", lcn);
+		/* Map and lock the mft record and get the attribute record. */
+		if (!NInoAttr(ni))
+			base_ni = ni;
+		else
+			base_ni = ni->ext.base_ntfs_ino;
+		m = map_mft_record(base_ni);
+		if (IS_ERR(m)) {
+			err = PTR_ERR(m);
+			break;
+		}
+		ctx = ntfs_attr_get_search_ctx(base_ni, m);
+		if (unlikely(!ctx)) {
+			err = -ENOMEM;
+			unmap_mft_record(base_ni);
+			break;
+		}
+		status.mft_attr_mapped = 1;
+		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+				CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
+		if (unlikely(err)) {
+			if (err == -ENOENT)
+				err = -EIO;
+			break;
+		}
+		m = ctx->mrec;
+		a = ctx->attr;
+		/*
+		 * Find the runlist element with which the attribute extent
+		 * starts.  Note, we cannot use the _attr_ version because we
+		 * have mapped the mft record.  That is ok because we know the
+		 * runlist fragment must be mapped already to have ever gotten
+		 * here, so we can just use the _rl_ version.
+		 */
+		vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
+		rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
+		BUG_ON(!rl2);
+		BUG_ON(!rl2->length);
+		BUG_ON(rl2->lcn < LCN_HOLE);
+		highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
+		/*
+		 * If @highest_vcn is zero, calculate the real highest_vcn
+		 * (which can really be zero).
+		 */
+		if (!highest_vcn)
+			highest_vcn = (sle64_to_cpu(
+					a->data.non_resident.allocated_size) >>
+					vol->cluster_size_bits) - 1;
+		/*
+		 * Determine the size of the mapping pairs array for the new
+		 * extent, i.e. the old extent with the hole filled.
+		 */
+		mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
+				highest_vcn);
+		if (unlikely(mp_size <= 0)) {
+			if (!(err = mp_size))
+				err = -EIO;
+			ntfs_debug("Failed to get size for mapping pairs "
+					"array, error code %i.", err);
+			break;
+		}
+		/*
+		 * Resize the attribute record to fit the new mapping pairs
+		 * array.
+		 */
+		attr_rec_len = le32_to_cpu(a->length);
+		err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
+				a->data.non_resident.mapping_pairs_offset));
+		if (unlikely(err)) {
+			BUG_ON(err != -ENOSPC);
+			// TODO: Deal with this by using the current attribute
+			// and fill it with as much of the mapping pairs
+			// array as possible.  Then loop over each attribute
+			// extent rewriting the mapping pairs arrays as we go
+			// along and if when we reach the end we have not
+			// enough space, try to resize the last attribute
+			// extent and if even that fails, add a new attribute
+			// extent.
+			// We could also try to resize at each step in the hope
+			// that we will not need to rewrite every single extent.
+			// Note, we may need to decompress some extents to fill
+			// the runlist as we are walking the extents...
+			ntfs_error(vol->sb, "Not enough space in the mft "
+					"record for the extended attribute "
+					"record.  This case is not "
+					"implemented yet.");
+			err = -EOPNOTSUPP;
+			break ;
+		}
+		status.mp_rebuilt = 1;
+		/*
+		 * Generate the mapping pairs array directly into the attribute
+		 * record.
+		 */
+		err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
+				a->data.non_resident.mapping_pairs_offset),
+				mp_size, rl2, vcn, highest_vcn, NULL);
+		if (unlikely(err)) {
+			ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
+					"attribute type 0x%x, because building "
+					"the mapping pairs failed with error "
+					"code %i.", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+			err = -EIO;
+			break;
+		}
+		/* Update the highest_vcn but only if it was not set. */
+		if (unlikely(!a->data.non_resident.highest_vcn))
+			a->data.non_resident.highest_vcn =
+					cpu_to_sle64(highest_vcn);
+		/*
+		 * If the attribute is sparse/compressed, update the compressed
+		 * size in the ntfs_inode structure and the attribute record.
+		 */
+		if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
+			/*
+			 * If we are not in the first attribute extent, switch
+			 * to it, but first ensure the changes will make it to
+			 * disk later.
+			 */
+			if (a->data.non_resident.lowest_vcn) {
+				flush_dcache_mft_record_page(ctx->ntfs_ino);
+				mark_mft_record_dirty(ctx->ntfs_ino);
+				ntfs_attr_reinit_search_ctx(ctx);
+				err = ntfs_attr_lookup(ni->type, ni->name,
+						ni->name_len, CASE_SENSITIVE,
+						0, NULL, 0, ctx);
+				if (unlikely(err)) {
+					status.attr_switched = 1;
+					break;
+				}
+				/* @m is not used any more so do not set it. */
+				a = ctx->attr;
+			}
+			write_lock_irqsave(&ni->size_lock, flags);
+			ni->itype.compressed.size += vol->cluster_size;
+			a->data.non_resident.compressed_size =
+					cpu_to_sle64(ni->itype.compressed.size);
+			write_unlock_irqrestore(&ni->size_lock, flags);
+		}
+		/* Ensure the changes make it to disk. */
+		flush_dcache_mft_record_page(ctx->ntfs_ino);
+		mark_mft_record_dirty(ctx->ntfs_ino);
+		ntfs_attr_put_search_ctx(ctx);
+		unmap_mft_record(base_ni);
+		/* Successfully filled the hole. */
+		status.runlist_merged = 0;
+		status.mft_attr_mapped = 0;
+		status.mp_rebuilt = 0;
+		/* Setup the map cache and use that to deal with the buffer. */
+		was_hole = TRUE;
+		vcn = bh_cpos;
+		vcn_len = 1;
+		lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
+		cdelta = 0;
+		/*
+		 * If the number of remaining clusters in the @pages is smaller
+		 * or equal to the number of cached clusters, unlock the
+		 * runlist as the map cache will be used from now on.
+		 */
+		if (likely(vcn + vcn_len >= cend)) {
+			up_write(&ni->runlist.lock);
+			rl_write_locked = FALSE;
+			rl = NULL;
+		}
+		goto map_buffer_cached;
+	} while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
+	/* If there are no errors, do the next page. */
+	if (likely(!err && ++u < nr_pages))
+		goto do_next_page;
+	/* If there are no errors, release the runlist lock if we took it. */
+	if (likely(!err)) {
+		if (unlikely(rl_write_locked)) {
+			up_write(&ni->runlist.lock);
+			rl_write_locked = FALSE;
+		} else if (unlikely(rl))
+			up_read(&ni->runlist.lock);
+		rl = NULL;
+	}
+	/* If we issued read requests, let them complete. */
+	read_lock_irqsave(&ni->size_lock, flags);
+	initialized_size = ni->initialized_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	while (wait_bh > wait) {
+		bh = *--wait_bh;
+		wait_on_buffer(bh);
+		if (likely(buffer_uptodate(bh))) {
+			page = bh->b_page;
+			bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) +
+					bh_offset(bh);
+			/*
+			 * If the buffer overflows the initialized size, need
+			 * to zero the overflowing region.
+			 */
+			if (unlikely(bh_pos + blocksize > initialized_size)) {
+				u8 *kaddr;
+				int ofs = 0;
+
+				if (likely(bh_pos < initialized_size))
+					ofs = initialized_size - bh_pos;
+				kaddr = kmap_atomic(page, KM_USER0);
+				memset(kaddr + bh_offset(bh) + ofs, 0,
+						blocksize - ofs);
+				kunmap_atomic(kaddr, KM_USER0);
+				flush_dcache_page(page);
+			}
+		} else /* if (unlikely(!buffer_uptodate(bh))) */
+			err = -EIO;
+	}
+	if (likely(!err)) {
+		/* Clear buffer_new on all buffers. */
+		u = 0;
+		do {
+			bh = head = page_buffers(pages[u]);
+			do {
+				if (buffer_new(bh))
+					clear_buffer_new(bh);
+			} while ((bh = bh->b_this_page) != head);
+		} while (++u < nr_pages);
+		ntfs_debug("Done.");
+		return err;
+	}
+	if (status.attr_switched) {
+		/* Get back to the attribute extent we modified. */
+		ntfs_attr_reinit_search_ctx(ctx);
+		if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+				CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
+			ntfs_error(vol->sb, "Failed to find required "
+					"attribute extent of attribute in "
+					"error code path.  Run chkdsk to "
+					"recover.");
+			write_lock_irqsave(&ni->size_lock, flags);
+			ni->itype.compressed.size += vol->cluster_size;
+			write_unlock_irqrestore(&ni->size_lock, flags);
+			flush_dcache_mft_record_page(ctx->ntfs_ino);
+			mark_mft_record_dirty(ctx->ntfs_ino);
+			/*
+			 * The only thing that is now wrong is the compressed
+			 * size of the base attribute extent which chkdsk
+			 * should be able to fix.
+			 */
+			NVolSetErrors(vol);
+		} else {
+			m = ctx->mrec;
+			a = ctx->attr;
+			status.attr_switched = 0;
+		}
+	}
+	/*
+	 * If the runlist has been modified, need to restore it by punching a
+	 * hole into it and we then need to deallocate the on-disk cluster as
+	 * well.  Note, we only modify the runlist if we are able to generate a
+	 * new mapping pairs array, i.e. only when the mapped attribute extent
+	 * is not switched.
+	 */
+	if (status.runlist_merged && !status.attr_switched) {
+		BUG_ON(!rl_write_locked);
+		/* Make the file cluster we allocated sparse in the runlist. */
+		if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
+			ntfs_error(vol->sb, "Failed to punch hole into "
+					"attribute runlist in error code "
+					"path.  Run chkdsk to recover the "
+					"lost cluster.");
+			make_bad_inode(vi);
+			make_bad_inode(VFS_I(base_ni));
+			NVolSetErrors(vol);
+		} else /* if (success) */ {
+			status.runlist_merged = 0;
+			/*
+			 * Deallocate the on-disk cluster we allocated but only
+			 * if we succeeded in punching its vcn out of the
+			 * runlist.
+			 */
+			down_write(&vol->lcnbmp_lock);
+			if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
+				ntfs_error(vol->sb, "Failed to release "
+						"allocated cluster in error "
+						"code path.  Run chkdsk to "
+						"recover the lost cluster.");
+				NVolSetErrors(vol);
+			}
+			up_write(&vol->lcnbmp_lock);
+		}
+	}
+	/*
+	 * Resize the attribute record to its old size and rebuild the mapping
+	 * pairs array.  Note, we only can do this if the runlist has been
+	 * restored to its old state which also implies that the mapped
+	 * attribute extent is not switched.
+	 */
+	if (status.mp_rebuilt && !status.runlist_merged) {
+		if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
+			ntfs_error(vol->sb, "Failed to restore attribute "
+					"record in error code path.  Run "
+					"chkdsk to recover.");
+			make_bad_inode(vi);
+			make_bad_inode(VFS_I(base_ni));
+			NVolSetErrors(vol);
+		} else /* if (success) */ {
+			if (ntfs_mapping_pairs_build(vol, (u8*)a +
+					le16_to_cpu(a->data.non_resident.
+					mapping_pairs_offset), attr_rec_len -
+					le16_to_cpu(a->data.non_resident.
+					mapping_pairs_offset), ni->runlist.rl,
+					vcn, highest_vcn, NULL)) {
+				ntfs_error(vol->sb, "Failed to restore "
+						"mapping pairs array in error "
+						"code path.  Run chkdsk to "
+						"recover.");
+				make_bad_inode(vi);
+				make_bad_inode(VFS_I(base_ni));
+				NVolSetErrors(vol);
+			}
+			flush_dcache_mft_record_page(ctx->ntfs_ino);
+			mark_mft_record_dirty(ctx->ntfs_ino);
+		}
+	}
+	/* Release the mft record and the attribute. */
+	if (status.mft_attr_mapped) {
+		ntfs_attr_put_search_ctx(ctx);
+		unmap_mft_record(base_ni);
+	}
+	/* Release the runlist lock. */
+	if (rl_write_locked)
+		up_write(&ni->runlist.lock);
+	else if (rl)
+		up_read(&ni->runlist.lock);
+	/*
+	 * Zero out any newly allocated blocks to avoid exposing stale data.
+	 * If BH_New is set, we know that the block was newly allocated above
+	 * and that it has not been fully zeroed and marked dirty yet.
+	 */
+	nr_pages = u;
+	u = 0;
+	end = bh_cpos << vol->cluster_size_bits;
+	do {
+		page = pages[u];
+		bh = head = page_buffers(page);
+		do {
+			if (u == nr_pages &&
+					((s64)page->index << PAGE_CACHE_SHIFT) +
+					bh_offset(bh) >= end)
+				break;
+			if (!buffer_new(bh))
+				continue;
+			clear_buffer_new(bh);
+			if (!buffer_uptodate(bh)) {
+				if (PageUptodate(page))
+					set_buffer_uptodate(bh);
+				else {
+					u8 *kaddr = kmap_atomic(page, KM_USER0);
+					memset(kaddr + bh_offset(bh), 0,
+							blocksize);
+					kunmap_atomic(kaddr, KM_USER0);
+					flush_dcache_page(page);
+					set_buffer_uptodate(bh);
+				}
+			}
+			mark_buffer_dirty(bh);
+		} while ((bh = bh->b_this_page) != head);
+	} while (++u <= nr_pages);
+	ntfs_error(vol->sb, "Failed.  Returning error code %i.", err);
+	return err;
+}
+
+/*
+ * Copy as much as we can into the pages and return the number of bytes which
+ * were sucessfully copied.  If a fault is encountered then clear the pages
+ * out to (ofs + bytes) and return the number of bytes which were copied.
+ */
+static inline size_t ntfs_copy_from_user(struct page **pages,
+		unsigned nr_pages, unsigned ofs, const char __user *buf,
+		size_t bytes)
+{
+	struct page **last_page = pages + nr_pages;
+	char *kaddr;
+	size_t total = 0;
+	unsigned len;
+	int left;
+
+	do {
+		len = PAGE_CACHE_SIZE - ofs;
+		if (len > bytes)
+			len = bytes;
+		kaddr = kmap_atomic(*pages, KM_USER0);
+		left = __copy_from_user_inatomic(kaddr + ofs, buf, len);
+		kunmap_atomic(kaddr, KM_USER0);
+		if (unlikely(left)) {
+			/* Do it the slow way. */
+			kaddr = kmap(*pages);
+			left = __copy_from_user(kaddr + ofs, buf, len);
+			kunmap(*pages);
+			if (unlikely(left))
+				goto err_out;
+		}
+		total += len;
+		bytes -= len;
+		if (!bytes)
+			break;
+		buf += len;
+		ofs = 0;
+	} while (++pages < last_page);
+out:
+	return total;
+err_out:
+	total += len - left;
+	/* Zero the rest of the target like __copy_from_user(). */
+	while (++pages < last_page) {
+		bytes -= len;
+		if (!bytes)
+			break;
+		len = PAGE_CACHE_SIZE;
+		if (len > bytes)
+			len = bytes;
+		kaddr = kmap_atomic(*pages, KM_USER0);
+		memset(kaddr, 0, len);
+		kunmap_atomic(kaddr, KM_USER0);
+	}
+	goto out;
+}
+
+static size_t __ntfs_copy_from_user_iovec(char *vaddr,
+		const struct iovec *iov, size_t iov_ofs, size_t bytes)
+{
+	size_t total = 0;
+
+	while (1) {
+		const char __user *buf = iov->iov_base + iov_ofs;
+		unsigned len;
+		size_t left;
+
+		len = iov->iov_len - iov_ofs;
+		if (len > bytes)
+			len = bytes;
+		left = __copy_from_user_inatomic(vaddr, buf, len);
+		total += len;
+		bytes -= len;
+		vaddr += len;
+		if (unlikely(left)) {
+			/*
+			 * Zero the rest of the target like __copy_from_user().
+			 */
+			memset(vaddr, 0, bytes);
+			total -= left;
+			break;
+		}
+		if (!bytes)
+			break;
+		iov++;
+		iov_ofs = 0;
+	}
+	return total;
+}
+
+static inline void ntfs_set_next_iovec(const struct iovec **iovp,
+		size_t *iov_ofsp, size_t bytes)
+{
+	const struct iovec *iov = *iovp;
+	size_t iov_ofs = *iov_ofsp;
+
+	while (bytes) {
+		unsigned len;
+
+		len = iov->iov_len - iov_ofs;
+		if (len > bytes)
+			len = bytes;
+		bytes -= len;
+		iov_ofs += len;
+		if (iov->iov_len == iov_ofs) {
+			iov++;
+			iov_ofs = 0;
+		}
+	}
+	*iovp = iov;
+	*iov_ofsp = iov_ofs;
+}
+
+/*
+ * This has the same side-effects and return value as ntfs_copy_from_user().
+ * The difference is that on a fault we need to memset the remainder of the
+ * pages (out to offset + bytes), to emulate ntfs_copy_from_user()'s
+ * single-segment behaviour.
+ *
+ * We call the same helper (__ntfs_copy_from_user_iovec()) both when atomic and
+ * when not atomic.  This is ok because __ntfs_copy_from_user_iovec() calls
+ * __copy_from_user_inatomic() and it is ok to call this when non-atomic.  In
+ * fact, the only difference between __copy_from_user_inatomic() and
+ * __copy_from_user() is that the latter calls might_sleep().  And on many
+ * architectures __copy_from_user_inatomic() is just defined to
+ * __copy_from_user() so it makes no difference at all on those architectures.
+ */
+static inline size_t ntfs_copy_from_user_iovec(struct page **pages,
+		unsigned nr_pages, unsigned ofs, const struct iovec **iov,
+		size_t *iov_ofs, size_t bytes)
+{
+	struct page **last_page = pages + nr_pages;
+	char *kaddr;
+	size_t copied, len, total = 0;
+
+	do {
+		len = PAGE_CACHE_SIZE - ofs;
+		if (len > bytes)
+			len = bytes;
+		kaddr = kmap_atomic(*pages, KM_USER0);
+		copied = __ntfs_copy_from_user_iovec(kaddr + ofs,
+				*iov, *iov_ofs, len);
+		kunmap_atomic(kaddr, KM_USER0);
+		if (unlikely(copied != len)) {
+			/* Do it the slow way. */
+			kaddr = kmap(*pages);
+			copied = __ntfs_copy_from_user_iovec(kaddr + ofs,
+					*iov, *iov_ofs, len);
+			kunmap(*pages);
+			if (unlikely(copied != len))
+				goto err_out;
+		}
+		total += len;
+		bytes -= len;
+		if (!bytes)
+			break;
+		ntfs_set_next_iovec(iov, iov_ofs, len);
+		ofs = 0;
+	} while (++pages < last_page);
+out:
+	return total;
+err_out:
+	total += copied;
+	/* Zero the rest of the target like __copy_from_user(). */
+	while (++pages < last_page) {
+		bytes -= len;
+		if (!bytes)
+			break;
+		len = PAGE_CACHE_SIZE;
+		if (len > bytes)
+			len = bytes;
+		kaddr = kmap_atomic(*pages, KM_USER0);
+		memset(kaddr, 0, len);
+		kunmap_atomic(kaddr, KM_USER0);
+	}
+	goto out;
+}
+
+static inline void ntfs_flush_dcache_pages(struct page **pages,
+		unsigned nr_pages)
+{
+	BUG_ON(!nr_pages);
+	do {
+		/*
+		 * Warning: Do not do the decrement at the same time as the
+		 * call because flush_dcache_page() is a NULL macro on i386
+		 * and hence the decrement never happens.
+		 */
+		flush_dcache_page(pages[nr_pages]);
+	} while (--nr_pages > 0);
+}
+
+/**
+ * ntfs_commit_pages_after_non_resident_write - commit the received data
+ * @pages:	array of destination pages
+ * @nr_pages:	number of pages in @pages
+ * @pos:	byte position in file at which the write begins
+ * @bytes:	number of bytes to be written
+ *
+ * See description of ntfs_commit_pages_after_write(), below.
+ */
+static inline int ntfs_commit_pages_after_non_resident_write(
+		struct page **pages, const unsigned nr_pages,
+		s64 pos, size_t bytes)
+{
+	s64 end, initialized_size;
+	struct inode *vi;
+	ntfs_inode *ni, *base_ni;
+	struct buffer_head *bh, *head;
+	ntfs_attr_search_ctx *ctx;
+	MFT_RECORD *m;
+	ATTR_RECORD *a;
+	unsigned long flags;
+	unsigned blocksize, u;
+	int err;
+
+	vi = pages[0]->mapping->host;
+	ni = NTFS_I(vi);
+	blocksize = 1 << vi->i_blkbits;
+	end = pos + bytes;
+	u = 0;
+	do {
+		s64 bh_pos;
+		struct page *page;
+		BOOL partial;
+
+		page = pages[u];
+		bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
+		bh = head = page_buffers(page);
+		partial = FALSE;
+		do {
+			s64 bh_end;
+
+			bh_end = bh_pos + blocksize;
+			if (bh_end <= pos || bh_pos >= end) {
+				if (!buffer_uptodate(bh))
+					partial = TRUE;
+			} else {
+				set_buffer_uptodate(bh);
+				mark_buffer_dirty(bh);
+			}
+		} while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
+		/*
+		 * If all buffers are now uptodate but the page is not, set the
+		 * page uptodate.
+		 */
+		if (!partial && !PageUptodate(page))
+			SetPageUptodate(page);
+	} while (++u < nr_pages);
+	/*
+	 * Finally, if we do not need to update initialized_size or i_size we
+	 * are finished.
+	 */
+	read_lock_irqsave(&ni->size_lock, flags);
+	initialized_size = ni->initialized_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	if (end <= initialized_size) {
+		ntfs_debug("Done.");
+		return 0;
+	}
+	/*
+	 * Update initialized_size/i_size as appropriate, both in the inode and
+	 * the mft record.
+	 */
+	if (!NInoAttr(ni))
+		base_ni = ni;
+	else
+		base_ni = ni->ext.base_ntfs_ino;
+	/* Map, pin, and lock the mft record. */
+	m = map_mft_record(base_ni);
+	if (IS_ERR(m)) {
+		err = PTR_ERR(m);
+		m = NULL;
+		ctx = NULL;
+		goto err_out;
+	}
+	BUG_ON(!NInoNonResident(ni));
+	ctx = ntfs_attr_get_search_ctx(base_ni, m);
+	if (unlikely(!ctx)) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+			CASE_SENSITIVE, 0, NULL, 0, ctx);
+	if (unlikely(err)) {
+		if (err == -ENOENT)
+			err = -EIO;
+		goto err_out;
+	}
+	a = ctx->attr;
+	BUG_ON(!a->non_resident);
+	write_lock_irqsave(&ni->size_lock, flags);
+	BUG_ON(end > ni->allocated_size);
+	ni->initialized_size = end;
+	a->data.non_resident.initialized_size = cpu_to_sle64(end);
+	if (end > i_size_read(vi)) {
+		i_size_write(vi, end);
+		a->data.non_resident.data_size =
+				a->data.non_resident.initialized_size;
+	}
+	write_unlock_irqrestore(&ni->size_lock, flags);
+	/* Mark the mft record dirty, so it gets written back. */
+	flush_dcache_mft_record_page(ctx->ntfs_ino);
+	mark_mft_record_dirty(ctx->ntfs_ino);
+	ntfs_attr_put_search_ctx(ctx);
+	unmap_mft_record(base_ni);
+	ntfs_debug("Done.");
+	return 0;
+err_out:
+	if (ctx)
+		ntfs_attr_put_search_ctx(ctx);
+	if (m)
+		unmap_mft_record(base_ni);
+	ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
+			"code %i).", err);
+	if (err != -ENOMEM) {
+		NVolSetErrors(ni->vol);
+		make_bad_inode(VFS_I(base_ni));
+		make_bad_inode(vi);
+	}
+	return err;
+}
+
+/**
+ * ntfs_commit_pages_after_write - commit the received data
+ * @pages:	array of destination pages
+ * @nr_pages:	number of pages in @pages
+ * @pos:	byte position in file at which the write begins
+ * @bytes:	number of bytes to be written
+ *
+ * This is called from ntfs_file_buffered_write() with i_sem held on the inode
+ * (@pages[0]->mapping->host).  There are @nr_pages pages in @pages which are
+ * locked but not kmap()ped.  The source data has already been copied into the
+ * @page.  ntfs_prepare_pages_for_non_resident_write() has been called before
+ * the data was copied (for non-resident attributes only) and it returned
+ * success.
+ *
+ * Need to set uptodate and mark dirty all buffers within the boundary of the
+ * write.  If all buffers in a page are uptodate we set the page uptodate, too.
+ *
+ * Setting the buffers dirty ensures that they get written out later when
+ * ntfs_writepage() is invoked by the VM.
+ *
+ * Finally, we need to update i_size and initialized_size as appropriate both
+ * in the inode and the mft record.
+ *
+ * This is modelled after fs/buffer.c::generic_commit_write(), which marks
+ * buffers uptodate and dirty, sets the page uptodate if all buffers in the
+ * page are uptodate, and updates i_size if the end of io is beyond i_size.  In
+ * that case, it also marks the inode dirty.
+ *
+ * If things have gone as outlined in
+ * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
+ * content modifications here for non-resident attributes.  For resident
+ * attributes we need to do the uptodate bringing here which we combine with
+ * the copying into the mft record which means we save one atomic kmap.
+ *
+ * Return 0 on success or -errno on error.
+ */
+static int ntfs_commit_pages_after_write(struct page **pages,
+		const unsigned nr_pages, s64 pos, size_t bytes)
+{
+	s64 end, initialized_size;
+	loff_t i_size;
+	struct inode *vi;
+	ntfs_inode *ni, *base_ni;
+	struct page *page;
+	ntfs_attr_search_ctx *ctx;
+	MFT_RECORD *m;
+	ATTR_RECORD *a;
+	char *kattr, *kaddr;
+	unsigned long flags;
+	u32 attr_len;
+	int err;
+
+	BUG_ON(!nr_pages);
+	BUG_ON(!pages);
+	page = pages[0];
+	BUG_ON(!page);
+	vi = page->mapping->host;
+	ni = NTFS_I(vi);
+	ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
+			"index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
+			vi->i_ino, ni->type, page->index, nr_pages,
+			(long long)pos, bytes);
+	if (NInoNonResident(ni))
+		return ntfs_commit_pages_after_non_resident_write(pages,
+				nr_pages, pos, bytes);
+	BUG_ON(nr_pages > 1);
+	/*
+	 * Attribute is resident, implying it is not compressed, encrypted, or
+	 * sparse.
+	 */
+	if (!NInoAttr(ni))
+		base_ni = ni;
+	else
+		base_ni = ni->ext.base_ntfs_ino;
+	BUG_ON(NInoNonResident(ni));
+	/* Map, pin, and lock the mft record. */
+	m = map_mft_record(base_ni);
+	if (IS_ERR(m)) {
+		err = PTR_ERR(m);
+		m = NULL;
+		ctx = NULL;
+		goto err_out;
+	}
+	ctx = ntfs_attr_get_search_ctx(base_ni, m);
+	if (unlikely(!ctx)) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+			CASE_SENSITIVE, 0, NULL, 0, ctx);
+	if (unlikely(err)) {
+		if (err == -ENOENT)
+			err = -EIO;
+		goto err_out;
+	}
+	a = ctx->attr;
+	BUG_ON(a->non_resident);
+	/* The total length of the attribute value. */
+	attr_len = le32_to_cpu(a->data.resident.value_length);
+	i_size = i_size_read(vi);
+	BUG_ON(attr_len != i_size);
+	BUG_ON(pos > attr_len);
+	end = pos + bytes;
+	BUG_ON(end > le32_to_cpu(a->length) -
+			le16_to_cpu(a->data.resident.value_offset));
+	kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
+	kaddr = kmap_atomic(page, KM_USER0);
+	/* Copy the received data from the page to the mft record. */
+	memcpy(kattr + pos, kaddr + pos, bytes);
+	/* Update the attribute length if necessary. */
+	if (end > attr_len) {
+		attr_len = end;
+		a->data.resident.value_length = cpu_to_le32(attr_len);
+	}
+	/*
+	 * If the page is not uptodate, bring the out of bounds area(s)
+	 * uptodate by copying data from the mft record to the page.
+	 */
+	if (!PageUptodate(page)) {
+		if (pos > 0)
+			memcpy(kaddr, kattr, pos);
+		if (end < attr_len)
+			memcpy(kaddr + end, kattr + end, attr_len - end);
+		/* Zero the region outside the end of the attribute value. */
+		memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
+		flush_dcache_page(page);
+		SetPageUptodate(page);
+	}
+	kunmap_atomic(kaddr, KM_USER0);
+	/* Update initialized_size/i_size if necessary. */
+	read_lock_irqsave(&ni->size_lock, flags);
+	initialized_size = ni->initialized_size;
+	BUG_ON(end > ni->allocated_size);
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	BUG_ON(initialized_size != i_size);
+	if (end > initialized_size) {
+		unsigned long flags;
+
+		write_lock_irqsave(&ni->size_lock, flags);
+		ni->initialized_size = end;
+		i_size_write(vi, end);
+		write_unlock_irqrestore(&ni->size_lock, flags);
+	}
+	/* Mark the mft record dirty, so it gets written back. */
+	flush_dcache_mft_record_page(ctx->ntfs_ino);
+	mark_mft_record_dirty(ctx->ntfs_ino);
+	ntfs_attr_put_search_ctx(ctx);
+	unmap_mft_record(base_ni);
+	ntfs_debug("Done.");
+	return 0;
+err_out:
+	if (err == -ENOMEM) {
+		ntfs_warning(vi->i_sb, "Error allocating memory required to "
+				"commit the write.");
+		if (PageUptodate(page)) {
+			ntfs_warning(vi->i_sb, "Page is uptodate, setting "
+					"dirty so the write will be retried "
+					"later on by the VM.");
+			/*
+			 * Put the page on mapping->dirty_pages, but leave its
+			 * buffers' dirty state as-is.
+			 */
+			__set_page_dirty_nobuffers(page);
+			err = 0;
+		} else
+			ntfs_error(vi->i_sb, "Page is not uptodate.  Written "
+					"data has been lost.");
+	} else {
+		ntfs_error(vi->i_sb, "Resident attribute commit write failed "
+				"with error %i.", err);
+		NVolSetErrors(ni->vol);
+		make_bad_inode(VFS_I(base_ni));
+		make_bad_inode(vi);
+	}
+	if (ctx)
+		ntfs_attr_put_search_ctx(ctx);
+	if (m)
+		unmap_mft_record(base_ni);
+	return err;
+}
+
+/**
+ * ntfs_file_buffered_write -
+ *
+ * Locking: The vfs is holding ->i_sem on the inode.
+ */
+static ssize_t ntfs_file_buffered_write(struct kiocb *iocb,
+		const struct iovec *iov, unsigned long nr_segs,
+		loff_t pos, loff_t *ppos, size_t count)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *vi = mapping->host;
+	ntfs_inode *ni = NTFS_I(vi);
+	ntfs_volume *vol = ni->vol;
+	struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
+	struct page *cached_page = NULL;
+	char __user *buf = NULL;
+	s64 end, ll;
+	VCN last_vcn;
+	LCN lcn;
+	unsigned long flags;
+	size_t bytes, iov_ofs = 0;	/* Offset in the current iovec. */
+	ssize_t status, written;
+	unsigned nr_pages;
+	int err;
+	struct pagevec lru_pvec;
+
+	ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
+			"pos 0x%llx, count 0x%lx.",
+			vi->i_ino, (unsigned)le32_to_cpu(ni->type),
+			(unsigned long long)pos, (unsigned long)count);
+	if (unlikely(!count))
+		return 0;
+	BUG_ON(NInoMstProtected(ni));
+	/*
+	 * If the attribute is not an index root and it is encrypted or
+	 * compressed, we cannot write to it yet.  Note we need to check for
+	 * AT_INDEX_ALLOCATION since this is the type of both directory and
+	 * index inodes.
+	 */
+	if (ni->type != AT_INDEX_ALLOCATION) {
+		/* If file is encrypted, deny access, just like NT4. */
+		if (NInoEncrypted(ni)) {
+			/*
+			 * Reminder for later: Encrypted files are _always_
+			 * non-resident so that the content can always be
+			 * encrypted.
+			 */
+			ntfs_debug("Denying write access to encrypted file.");
+			return -EACCES;
+		}
+		if (NInoCompressed(ni)) {
+			/* Only unnamed $DATA attribute can be compressed. */
+			BUG_ON(ni->type != AT_DATA);
+			BUG_ON(ni->name_len);
+			/*
+			 * Reminder for later: If resident, the data is not
+			 * actually compressed.  Only on the switch to non-
+			 * resident does compression kick in.  This is in
+			 * contrast to encrypted files (see above).
+			 */
+			ntfs_error(vi->i_sb, "Writing to compressed files is "
+					"not implemented yet.  Sorry.");
+			return -EOPNOTSUPP;
+		}
+	}
+	/*
+	 * If a previous ntfs_truncate() failed, repeat it and abort if it
+	 * fails again.
+	 */
+	if (unlikely(NInoTruncateFailed(ni))) {
+		down_write(&vi->i_alloc_sem);
+		err = ntfs_truncate(vi);
+		up_write(&vi->i_alloc_sem);
+		if (err || NInoTruncateFailed(ni)) {
+			if (!err)
+				err = -EIO;
+			ntfs_error(vol->sb, "Cannot perform write to inode "
+					"0x%lx, attribute type 0x%x, because "
+					"ntfs_truncate() failed (error code "
+					"%i).", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+			return err;
+		}
+	}
+	/* The first byte after the write. */
+	end = pos + count;
+	/*
+	 * If the write goes beyond the allocated size, extend the allocation
+	 * to cover the whole of the write, rounded up to the nearest cluster.
+	 */
+	read_lock_irqsave(&ni->size_lock, flags);
+	ll = ni->allocated_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	if (end > ll) {
+		/* Extend the allocation without changing the data size. */
+		ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
+		if (likely(ll >= 0)) {
+			BUG_ON(pos >= ll);
+			/* If the extension was partial truncate the write. */
+			if (end > ll) {
+				ntfs_debug("Truncating write to inode 0x%lx, "
+						"attribute type 0x%x, because "
+						"the allocation was only "
+						"partially extended.",
+						vi->i_ino, (unsigned)
+						le32_to_cpu(ni->type));
+				end = ll;
+				count = ll - pos;
+			}
+		} else {
+			err = ll;
+			read_lock_irqsave(&ni->size_lock, flags);
+			ll = ni->allocated_size;
+			read_unlock_irqrestore(&ni->size_lock, flags);
+			/* Perform a partial write if possible or fail. */
+			if (pos < ll) {
+				ntfs_debug("Truncating write to inode 0x%lx, "
+						"attribute type 0x%x, because "
+						"extending the allocation "
+						"failed (error code %i).",
+						vi->i_ino, (unsigned)
+						le32_to_cpu(ni->type), err);
+				end = ll;
+				count = ll - pos;
+			} else {
+				ntfs_error(vol->sb, "Cannot perform write to "
+						"inode 0x%lx, attribute type "
+						"0x%x, because extending the "
+						"allocation failed (error "
+						"code %i).", vi->i_ino,
+						(unsigned)
+						le32_to_cpu(ni->type), err);
+				return err;
+			}
+		}
+	}
+	pagevec_init(&lru_pvec, 0);
+	written = 0;
+	/*
+	 * If the write starts beyond the initialized size, extend it up to the
+	 * beginning of the write and initialize all non-sparse space between
+	 * the old initialized size and the new one.  This automatically also
+	 * increments the vfs inode->i_size to keep it above or equal to the
+	 * initialized_size.
+	 */
+	read_lock_irqsave(&ni->size_lock, flags);
+	ll = ni->initialized_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	if (pos > ll) {
+		err = ntfs_attr_extend_initialized(ni, pos, &cached_page,
+				&lru_pvec);
+		if (err < 0) {
+			ntfs_error(vol->sb, "Cannot perform write to inode "
+					"0x%lx, attribute type 0x%x, because "
+					"extending the initialized size "
+					"failed (error code %i).", vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type), err);
+			status = err;
+			goto err_out;
+		}
+	}
+	/*
+	 * Determine the number of pages per cluster for non-resident
+	 * attributes.
+	 */
+	nr_pages = 1;
+	if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni))
+		nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT;
+	/* Finally, perform the actual write. */
+	last_vcn = -1;
+	if (likely(nr_segs == 1))
+		buf = iov->iov_base;
+	do {
+		VCN vcn;
+		pgoff_t idx, start_idx;
+		unsigned ofs, do_pages, u;
+		size_t copied;
+
+		start_idx = idx = pos >> PAGE_CACHE_SHIFT;
+		ofs = pos & ~PAGE_CACHE_MASK;
+		bytes = PAGE_CACHE_SIZE - ofs;
+		do_pages = 1;
+		if (nr_pages > 1) {
+			vcn = pos >> vol->cluster_size_bits;
+			if (vcn != last_vcn) {
+				last_vcn = vcn;
+				/*
+				 * Get the lcn of the vcn the write is in.  If
+				 * it is a hole, need to lock down all pages in
+				 * the cluster.
+				 */
+				down_read(&ni->runlist.lock);
+				lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
+						vol->cluster_size_bits, FALSE);
+				up_read(&ni->runlist.lock);
+				if (unlikely(lcn < LCN_HOLE)) {
+					status = -EIO;
+					if (lcn == LCN_ENOMEM)
+						status = -ENOMEM;
+					else
+						ntfs_error(vol->sb, "Cannot "
+							"perform write to "
+							"inode 0x%lx, "
+							"attribute type 0x%x, "
+							"because the attribute "
+							"is corrupt.",
+							vi->i_ino, (unsigned)
+							le32_to_cpu(ni->type));
+					break;
+				}
+				if (lcn == LCN_HOLE) {
+					start_idx = (pos & ~(s64)
+							vol->cluster_size_mask)
+							>> PAGE_CACHE_SHIFT;
+					bytes = vol->cluster_size - (pos &
+							vol->cluster_size_mask);
+					do_pages = nr_pages;
+				}
+			}
+		}
+		if (bytes > count)
+			bytes = count;
+		/*
+		 * Bring in the user page(s) that we will copy from _first_.
+		 * Otherwise there is a nasty deadlock on copying from the same
+		 * page(s) as we are writing to, without it/them being marked
+		 * up-to-date.  Note, at present there is nothing to stop the
+		 * pages being swapped out between us bringing them into memory
+		 * and doing the actual copying.
+		 */
+		if (likely(nr_segs == 1))
+			ntfs_fault_in_pages_readable(buf, bytes);
+		else
+			ntfs_fault_in_pages_readable_iovec(iov, iov_ofs, bytes);
+		/* Get and lock @do_pages starting at index @start_idx. */
+		status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
+				pages, &cached_page, &lru_pvec);
+		if (unlikely(status))
+			break;
+		/*
+		 * For non-resident attributes, we need to fill any holes with
+		 * actual clusters and ensure all bufferes are mapped.  We also
+		 * need to bring uptodate any buffers that are only partially
+		 * being written to.
+		 */
+		if (NInoNonResident(ni)) {
+			status = ntfs_prepare_pages_for_non_resident_write(
+					pages, do_pages, pos, bytes);
+			if (unlikely(status)) {
+				loff_t i_size;
+
+				do {
+					unlock_page(pages[--do_pages]);
+					page_cache_release(pages[do_pages]);
+				} while (do_pages);
+				/*
+				 * The write preparation may have instantiated
+				 * allocated space outside i_size.  Trim this
+				 * off again.  We can ignore any errors in this
+				 * case as we will just be waisting a bit of
+				 * allocated space, which is not a disaster.
+				 */
+				i_size = i_size_read(vi);
+				if (pos + bytes > i_size)
+					vmtruncate(vi, i_size);
+				break;
+			}
+		}
+		u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index;
+		if (likely(nr_segs == 1)) {
+			copied = ntfs_copy_from_user(pages + u, do_pages - u,
+					ofs, buf, bytes);
+			buf += copied;
+		} else
+			copied = ntfs_copy_from_user_iovec(pages + u,
+					do_pages - u, ofs, &iov, &iov_ofs,
+					bytes);
+		ntfs_flush_dcache_pages(pages + u, do_pages - u);
+		status = ntfs_commit_pages_after_write(pages, do_pages, pos,
+				bytes);
+		if (likely(!status)) {
+			written += copied;
+			count -= copied;
+			pos += copied;
+			if (unlikely(copied != bytes))
+				status = -EFAULT;
+		}
+		do {
+			unlock_page(pages[--do_pages]);
+			mark_page_accessed(pages[do_pages]);
+			page_cache_release(pages[do_pages]);
+		} while (do_pages);
+		if (unlikely(status))
+			break;
+		balance_dirty_pages_ratelimited(mapping);
+		cond_resched();
+	} while (count);
+err_out:
+	*ppos = pos;
+	if (cached_page)
+		page_cache_release(cached_page);
+	/* For now, when the user asks for O_SYNC, we actually give O_DSYNC. */
+	if (likely(!status)) {
+		if (unlikely((file->f_flags & O_SYNC) || IS_SYNC(vi))) {
+			if (!mapping->a_ops->writepage || !is_sync_kiocb(iocb))
+				status = generic_osync_inode(vi, mapping,
+						OSYNC_METADATA|OSYNC_DATA);
+		}
+  	}
+	pagevec_lru_add(&lru_pvec);
+	ntfs_debug("Done.  Returning %s (written 0x%lx, status %li).",
+			written ? "written" : "status", (unsigned long)written,
+			(long)status);
+	return written ? written : status;
+}
+
+/**
+ * ntfs_file_aio_write_nolock -
+ */
+static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb,
+		const struct iovec *iov, unsigned long nr_segs, loff_t *ppos)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	loff_t pos;
+	unsigned long seg;
+	size_t count;		/* after file limit checks */
+	ssize_t written, err;
+
+	count = 0;
+	for (seg = 0; seg < nr_segs; seg++) {
+		const struct iovec *iv = &iov[seg];
+		/*
+		 * If any segment has a negative length, or the cumulative
+		 * length ever wraps negative then return -EINVAL.
+		 */
+		count += iv->iov_len;
+		if (unlikely((ssize_t)(count|iv->iov_len) < 0))
+			return -EINVAL;
+		if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
+			continue;
+		if (!seg)
+			return -EFAULT;
+		nr_segs = seg;
+		count -= iv->iov_len;	/* This segment is no good */
+		break;
+	}
+	pos = *ppos;
+	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+	/* We can write back this queue in page reclaim. */
+	current->backing_dev_info = mapping->backing_dev_info;
+	written = 0;
+	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+	if (err)
+		goto out;
+	if (!count)
+		goto out;
+	err = remove_suid(file->f_dentry);
+	if (err)
+		goto out;
+	inode_update_time(inode, 1);
+	written = ntfs_file_buffered_write(iocb, iov, nr_segs, pos, ppos,
+			count);
+out:
+	current->backing_dev_info = NULL;
+	return written ? written : err;
+}
+
+/**
+ * ntfs_file_aio_write -
+ */
+static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const char __user *buf,
+		size_t count, loff_t pos)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	ssize_t ret;
+	struct iovec local_iov = { .iov_base = (void __user *)buf,
+				   .iov_len = count };
+
+	BUG_ON(iocb->ki_pos != pos);
+
+	down(&inode->i_sem);
+	ret = ntfs_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
+	up(&inode->i_sem);
+	if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+		int err = sync_page_range(inode, mapping, pos, ret);
+		if (err < 0)
+			ret = err;
+	}
+	return ret;
+}
+
+/**
+ * ntfs_file_writev -
+ *
+ * Basically the same as generic_file_writev() except that it ends up calling
+ * ntfs_file_aio_write_nolock() instead of __generic_file_aio_write_nolock().
+ */
+static ssize_t ntfs_file_writev(struct file *file, const struct iovec *iov,
+		unsigned long nr_segs, loff_t *ppos)
+{
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	down(&inode->i_sem);
+	init_sync_kiocb(&kiocb, file);
+	ret = ntfs_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
+	if (ret == -EIOCBQUEUED)
+		ret = wait_on_sync_kiocb(&kiocb);
+	up(&inode->i_sem);
+	if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+		int err = sync_page_range(inode, mapping, *ppos - ret, ret);
+		if (err < 0)
+			ret = err;
+	}
+	return ret;
+}
+
+/**
+ * ntfs_file_write - simple wrapper for ntfs_file_writev()
+ */
+static ssize_t ntfs_file_write(struct file *file, const char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct iovec local_iov = { .iov_base = (void __user *)buf,
+				   .iov_len = count };
+
+	return ntfs_file_writev(file, &local_iov, 1, ppos);
+}
+
+/**
  * ntfs_file_fsync - sync a file to disk
  * @filp:	file to be synced
  * @dentry:	dentry describing the file to sync
@@ -94,6 +2286,11 @@ static int ntfs_file_fsync(struct file *filp, struct dentry *dentry,
 	if (!datasync || !NInoNonResident(NTFS_I(vi)))
 		ret = ntfs_write_inode(vi, 1);
 	write_inode_now(vi, !datasync);
+	/*
+	 * NOTE: If we were to use mapping->private_list (see ext2 and
+	 * fs/buffer.c) for dirty blocks then we could optimize the below to be
+	 * sync_mapping_buffers(vi->i_mapping).
+	 */
 	err = sync_blockdev(vi->i_sb->s_bdev);
 	if (unlikely(err && !ret))
 		ret = err;
@@ -108,39 +2305,39 @@ static int ntfs_file_fsync(struct file *filp, struct dentry *dentry,
 #endif /* NTFS_RW */
 
 struct file_operations ntfs_file_ops = {
-	.llseek		= generic_file_llseek,	  /* Seek inside file. */
-	.read		= generic_file_read,	  /* Read from file. */
-	.aio_read	= generic_file_aio_read,  /* Async read from file. */
-	.readv		= generic_file_readv,	  /* Read from file. */
+	.llseek		= generic_file_llseek,	 /* Seek inside file. */
+	.read		= generic_file_read,	 /* Read from file. */
+	.aio_read	= generic_file_aio_read, /* Async read from file. */
+	.readv		= generic_file_readv,	 /* Read from file. */
 #ifdef NTFS_RW
-	.write		= generic_file_write,	  /* Write to file. */
-	.aio_write	= generic_file_aio_write, /* Async write to file. */
-	.writev		= generic_file_writev,	  /* Write to file. */
-	/*.release	= ,*/			  /* Last file is closed.  See
-						     fs/ext2/file.c::
-						     ext2_release_file() for
-						     how to use this to discard
-						     preallocated space for
-						     write opened files. */
-	.fsync		= ntfs_file_fsync,	  /* Sync a file to disk. */
-	/*.aio_fsync	= ,*/			  /* Sync all outstanding async
-						     i/o operations on a
-						     kiocb. */
+	.write		= ntfs_file_write,	 /* Write to file. */
+	.aio_write	= ntfs_file_aio_write,	 /* Async write to file. */
+	.writev		= ntfs_file_writev,	 /* Write to file. */
+	/*.release	= ,*/			 /* Last file is closed.  See
+						    fs/ext2/file.c::
+						    ext2_release_file() for
+						    how to use this to discard
+						    preallocated space for
+						    write opened files. */
+	.fsync		= ntfs_file_fsync,	 /* Sync a file to disk. */
+	/*.aio_fsync	= ,*/			 /* Sync all outstanding async
+						    i/o operations on a
+						    kiocb. */
 #endif /* NTFS_RW */
-	/*.ioctl	= ,*/			  /* Perform function on the
-						     mounted filesystem. */
-	.mmap		= generic_file_mmap,	  /* Mmap file. */
-	.open		= ntfs_file_open,	  /* Open file. */
-	.sendfile	= generic_file_sendfile,  /* Zero-copy data send with
-						     the data source being on
-						     the ntfs partition.  We
-						     do not need to care about
-						     the data destination. */
-	/*.sendpage	= ,*/			  /* Zero-copy data send with
-						     the data destination being
-						     on the ntfs partition.  We
-						     do not need to care about
-						     the data source. */
+	/*.ioctl	= ,*/			 /* Perform function on the
+						    mounted filesystem. */
+	.mmap		= generic_file_mmap,	 /* Mmap file. */
+	.open		= ntfs_file_open,	 /* Open file. */
+	.sendfile	= generic_file_sendfile, /* Zero-copy data send with
+						    the data source being on
+						    the ntfs partition.  We do
+						    not need to care about the
+						    data destination. */
+	/*.sendpage	= ,*/			 /* Zero-copy data send with
+						    the data destination being
+						    on the ntfs partition.  We
+						    do not need to care about
+						    the data source. */
 };
 
 struct inode_operations ntfs_file_inode_ops = {
diff --git a/fs/ntfs/index.c b/fs/ntfs/index.c
index 11fd5307d780..8f2d5727546f 100644
--- a/fs/ntfs/index.c
+++ b/fs/ntfs/index.c
@@ -205,6 +205,7 @@ int ntfs_index_lookup(const void *key, const int key_len,
 				&ie->key, key_len)) {
 ir_done:
 			ictx->is_in_root = TRUE;
+			ictx->ir = ir;
 			ictx->actx = actx;
 			ictx->base_ni = base_ni;
 			ictx->ia = NULL;
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 886214a77f90..b24f4c4b2c5c 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -30,6 +30,7 @@
 #include "debug.h"
 #include "inode.h"
 #include "attrib.h"
+#include "lcnalloc.h"
 #include "malloc.h"
 #include "mft.h"
 #include "time.h"
@@ -1013,41 +1014,50 @@ skip_large_dir_stuff:
 		}
 		a = ctx->attr;
 		/* Setup the state. */
-		if (a->non_resident) {
-			NInoSetNonResident(ni);
-			if (a->flags & (ATTR_COMPRESSION_MASK |
-					ATTR_IS_SPARSE)) {
-				if (a->flags & ATTR_COMPRESSION_MASK) {
-					NInoSetCompressed(ni);
-					if (vol->cluster_size > 4096) {
-						ntfs_error(vi->i_sb, "Found "
+		if (a->flags & (ATTR_COMPRESSION_MASK | ATTR_IS_SPARSE)) {
+			if (a->flags & ATTR_COMPRESSION_MASK) {
+				NInoSetCompressed(ni);
+				if (vol->cluster_size > 4096) {
+					ntfs_error(vi->i_sb, "Found "
 							"compressed data but "
 							"compression is "
 							"disabled due to "
 							"cluster size (%i) > "
 							"4kiB.",
 							vol->cluster_size);
-						goto unm_err_out;
-					}
-					if ((a->flags & ATTR_COMPRESSION_MASK)
-							!= ATTR_IS_COMPRESSED) {
-						ntfs_error(vi->i_sb, "Found "
-							"unknown compression "
-							"method or corrupt "
-							"file.");
-						goto unm_err_out;
-					}
+					goto unm_err_out;
 				}
-				if (a->flags & ATTR_IS_SPARSE)
-					NInoSetSparse(ni);
+				if ((a->flags & ATTR_COMPRESSION_MASK)
+						!= ATTR_IS_COMPRESSED) {
+					ntfs_error(vi->i_sb, "Found unknown "
+							"compression method "
+							"or corrupt file.");
+					goto unm_err_out;
+				}
+			}
+			if (a->flags & ATTR_IS_SPARSE)
+				NInoSetSparse(ni);
+		}
+		if (a->flags & ATTR_IS_ENCRYPTED) {
+			if (NInoCompressed(ni)) {
+				ntfs_error(vi->i_sb, "Found encrypted and "
+						"compressed data.");
+				goto unm_err_out;
+			}
+			NInoSetEncrypted(ni);
+		}
+		if (a->non_resident) {
+			NInoSetNonResident(ni);
+			if (NInoCompressed(ni) || NInoSparse(ni)) {
 				if (a->data.non_resident.compression_unit !=
 						4) {
 					ntfs_error(vi->i_sb, "Found "
-						"nonstandard compression unit "
-						"(%u instead of 4).  Cannot "
-						"handle this.",
-						a->data.non_resident.
-						compression_unit);
+							"nonstandard "
+							"compression unit (%u "
+							"instead of 4).  "
+							"Cannot handle this.",
+							a->data.non_resident.
+							compression_unit);
 					err = -EOPNOTSUPP;
 					goto unm_err_out;
 				}
@@ -1065,14 +1075,6 @@ skip_large_dir_stuff:
 						a->data.non_resident.
 						compressed_size);
 			}
-			if (a->flags & ATTR_IS_ENCRYPTED) {
-				if (a->flags & ATTR_COMPRESSION_MASK) {
-					ntfs_error(vi->i_sb, "Found encrypted "
-							"and compressed data.");
-					goto unm_err_out;
-				}
-				NInoSetEncrypted(ni);
-			}
 			if (a->data.non_resident.lowest_vcn) {
 				ntfs_error(vi->i_sb, "First extent of $DATA "
 						"attribute has non zero "
@@ -1165,6 +1167,8 @@ err_out:
  *
  * Return 0 on success and -errno on error.  In the error case, the inode will
  * have had make_bad_inode() executed on it.
+ *
+ * Note this cannot be called for AT_INDEX_ALLOCATION.
  */
 static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 {
@@ -1212,6 +1216,75 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 	if (unlikely(err))
 		goto unm_err_out;
 	a = ctx->attr;
+	if (a->flags & (ATTR_COMPRESSION_MASK | ATTR_IS_SPARSE)) {
+		if (a->flags & ATTR_COMPRESSION_MASK) {
+			NInoSetCompressed(ni);
+			if ((ni->type != AT_DATA) || (ni->type == AT_DATA &&
+					ni->name_len)) {
+				ntfs_error(vi->i_sb, "Found compressed "
+						"non-data or named data "
+						"attribute.  Please report "
+						"you saw this message to "
+						"linux-ntfs-dev@lists."
+						"sourceforge.net");
+				goto unm_err_out;
+			}
+			if (vol->cluster_size > 4096) {
+				ntfs_error(vi->i_sb, "Found compressed "
+						"attribute but compression is "
+						"disabled due to cluster size "
+						"(%i) > 4kiB.",
+						vol->cluster_size);
+				goto unm_err_out;
+			}
+			if ((a->flags & ATTR_COMPRESSION_MASK) !=
+					ATTR_IS_COMPRESSED) {
+				ntfs_error(vi->i_sb, "Found unknown "
+						"compression method.");
+				goto unm_err_out;
+			}
+		}
+		/*
+		 * The compressed/sparse flag set in an index root just means
+		 * to compress all files.
+		 */
+		if (NInoMstProtected(ni) && ni->type != AT_INDEX_ROOT) {
+			ntfs_error(vi->i_sb, "Found mst protected attribute "
+					"but the attribute is %s.  Please "
+					"report you saw this message to "
+					"linux-ntfs-dev@lists.sourceforge.net",
+					NInoCompressed(ni) ? "compressed" :
+					"sparse");
+			goto unm_err_out;
+		}
+		if (a->flags & ATTR_IS_SPARSE)
+			NInoSetSparse(ni);
+	}
+	if (a->flags & ATTR_IS_ENCRYPTED) {
+		if (NInoCompressed(ni)) {
+			ntfs_error(vi->i_sb, "Found encrypted and compressed "
+					"data.");
+			goto unm_err_out;
+		}
+		/*
+		 * The encryption flag set in an index root just means to
+		 * encrypt all files.
+		 */
+		if (NInoMstProtected(ni) && ni->type != AT_INDEX_ROOT) {
+			ntfs_error(vi->i_sb, "Found mst protected attribute "
+					"but the attribute is encrypted.  "
+					"Please report you saw this message "
+					"to linux-ntfs-dev@lists.sourceforge."
+					"net");
+			goto unm_err_out;
+		}
+		if (ni->type != AT_DATA) {
+			ntfs_error(vi->i_sb, "Found encrypted non-data "
+					"attribute.");
+			goto unm_err_out;
+		}
+		NInoSetEncrypted(ni);
+	}
 	if (!a->non_resident) {
 		/* Ensure the attribute name is placed before the value. */
 		if (unlikely(a->name_length && (le16_to_cpu(a->name_offset) >=
@@ -1220,11 +1293,10 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 					"the attribute value.");
 			goto unm_err_out;
 		}
-		if (NInoMstProtected(ni) || a->flags) {
+		if (NInoMstProtected(ni)) {
 			ntfs_error(vi->i_sb, "Found mst protected attribute "
-					"or attribute with non-zero flags but "
-					"the attribute is resident.  Please "
-					"report you saw this message to "
+					"but the attribute is resident.  "
+					"Please report you saw this message to "
 					"linux-ntfs-dev@lists.sourceforge.net");
 			goto unm_err_out;
 		}
@@ -1250,50 +1322,7 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 					"the mapping pairs array.");
 			goto unm_err_out;
 		}
-		if (a->flags & (ATTR_COMPRESSION_MASK | ATTR_IS_SPARSE)) {
-			if (a->flags & ATTR_COMPRESSION_MASK) {
-				NInoSetCompressed(ni);
-				if ((ni->type != AT_DATA) || (ni->type ==
-						AT_DATA && ni->name_len)) {
-					ntfs_error(vi->i_sb, "Found compressed "
-							"non-data or named "
-							"data attribute.  "
-							"Please report you "
-							"saw this message to "
-							"linux-ntfs-dev@lists."
-							"sourceforge.net");
-					goto unm_err_out;
-				}
-				if (vol->cluster_size > 4096) {
-					ntfs_error(vi->i_sb, "Found compressed "
-							"attribute but "
-							"compression is "
-							"disabled due to "
-							"cluster size (%i) > "
-							"4kiB.",
-							vol->cluster_size);
-					goto unm_err_out;
-				}
-				if ((a->flags & ATTR_COMPRESSION_MASK) !=
-						ATTR_IS_COMPRESSED) {
-					ntfs_error(vi->i_sb, "Found unknown "
-							"compression method.");
-					goto unm_err_out;
-				}
-			}
-			if (NInoMstProtected(ni)) {
-				ntfs_error(vi->i_sb, "Found mst protected "
-						"attribute but the attribute "
-						"is %s.  Please report you "
-						"saw this message to "
-						"linux-ntfs-dev@lists."
-						"sourceforge.net",
-						NInoCompressed(ni) ?
-						"compressed" : "sparse");
-				goto unm_err_out;
-			}
-			if (a->flags & ATTR_IS_SPARSE)
-				NInoSetSparse(ni);
+		if (NInoCompressed(ni) || NInoSparse(ni)) {
 			if (a->data.non_resident.compression_unit != 4) {
 				ntfs_error(vi->i_sb, "Found nonstandard "
 						"compression unit (%u instead "
@@ -1313,23 +1342,6 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 			ni->itype.compressed.size = sle64_to_cpu(
 					a->data.non_resident.compressed_size);
 		}
-		if (a->flags & ATTR_IS_ENCRYPTED) {
-			if (a->flags & ATTR_COMPRESSION_MASK) {
-				ntfs_error(vi->i_sb, "Found encrypted and "
-						"compressed data.");
-				goto unm_err_out;
-			}
-			if (NInoMstProtected(ni)) {
-				ntfs_error(vi->i_sb, "Found mst protected "
-						"attribute but the attribute "
-						"is encrypted.  Please report "
-						"you saw this message to "
-						"linux-ntfs-dev@lists."
-						"sourceforge.net");
-				goto unm_err_out;
-			}
-			NInoSetEncrypted(ni);
-		}
 		if (a->data.non_resident.lowest_vcn) {
 			ntfs_error(vi->i_sb, "First extent of attribute has "
 					"non-zero lowest_vcn.");
@@ -1348,12 +1360,12 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 		vi->i_mapping->a_ops = &ntfs_mst_aops;
 	else
 		vi->i_mapping->a_ops = &ntfs_aops;
-	if (NInoCompressed(ni) || NInoSparse(ni))
+	if ((NInoCompressed(ni) || NInoSparse(ni)) && ni->type != AT_INDEX_ROOT)
 		vi->i_blocks = ni->itype.compressed.size >> 9;
 	else
 		vi->i_blocks = ni->allocated_size >> 9;
 	/*
-	 * Make sure the base inode doesn't go away and attach it to the
+	 * Make sure the base inode does not go away and attach it to the
 	 * attribute inode.
 	 */
 	igrab(base_vi);
@@ -1480,7 +1492,10 @@ static int ntfs_read_locked_index_inode(struct inode *base_vi, struct inode *vi)
 				"after the attribute value.");
 		goto unm_err_out;
 	}
-	/* Compressed/encrypted/sparse index root is not allowed. */
+	/*
+	 * Compressed/encrypted/sparse index root is not allowed, except for
+	 * directories of course but those are not dealt with here.
+	 */
 	if (a->flags & (ATTR_COMPRESSION_MASK | ATTR_IS_ENCRYPTED |
 			ATTR_IS_SPARSE)) {
 		ntfs_error(vi->i_sb, "Found compressed/encrypted/sparse index "
@@ -2277,11 +2292,16 @@ int ntfs_show_options(struct seq_file *sf, struct vfsmount *mnt)
 
 #ifdef NTFS_RW
 
+static const char *es = "  Leaving inconsistent metadata.  Unmount and run "
+		"chkdsk.";
+
 /**
  * ntfs_truncate - called when the i_size of an ntfs inode is changed
  * @vi:		inode for which the i_size was changed
  *
- * We do not support i_size changes yet.
+ * We only support i_size changes for normal files at present, i.e. not
+ * compressed and not encrypted.  This is enforced in ntfs_setattr(), see
+ * below.
  *
  * The kernel guarantees that @vi is a regular file (S_ISREG() is true) and
  * that the change is allowed.
@@ -2292,80 +2312,499 @@ int ntfs_show_options(struct seq_file *sf, struct vfsmount *mnt)
  * Returns 0 on success or -errno on error.
  *
  * Called with ->i_sem held.  In all but one case ->i_alloc_sem is held for
- * writing.  The only case where ->i_alloc_sem is not held is
+ * writing.  The only case in the kernel where ->i_alloc_sem is not held is
  * mm/filemap.c::generic_file_buffered_write() where vmtruncate() is called
- * with the current i_size as the offset which means that it is a noop as far
- * as ntfs_truncate() is concerned.
+ * with the current i_size as the offset.  The analogous place in NTFS is in
+ * fs/ntfs/file.c::ntfs_file_buffered_write() where we call vmtruncate() again
+ * without holding ->i_alloc_sem.
  */
 int ntfs_truncate(struct inode *vi)
 {
-	ntfs_inode *ni = NTFS_I(vi);
+	s64 new_size, old_size, nr_freed, new_alloc_size, old_alloc_size;
+	VCN highest_vcn;
+	unsigned long flags;
+	ntfs_inode *base_ni, *ni = NTFS_I(vi);
 	ntfs_volume *vol = ni->vol;
 	ntfs_attr_search_ctx *ctx;
 	MFT_RECORD *m;
 	ATTR_RECORD *a;
 	const char *te = "  Leaving file length out of sync with i_size.";
-	int err;
+	int err, mp_size, size_change, alloc_change;
+	u32 attr_len;
 
 	ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
 	BUG_ON(NInoAttr(ni));
+	BUG_ON(S_ISDIR(vi->i_mode));
+	BUG_ON(NInoMstProtected(ni));
 	BUG_ON(ni->nr_extents < 0);
-	m = map_mft_record(ni);
+retry_truncate:
+	/*
+	 * Lock the runlist for writing and map the mft record to ensure it is
+	 * safe to mess with the attribute runlist and sizes.
+	 */
+	down_write(&ni->runlist.lock);
+	if (!NInoAttr(ni))
+		base_ni = ni;
+	else
+		base_ni = ni->ext.base_ntfs_ino;
+	m = map_mft_record(base_ni);
 	if (IS_ERR(m)) {
 		err = PTR_ERR(m);
 		ntfs_error(vi->i_sb, "Failed to map mft record for inode 0x%lx "
 				"(error code %d).%s", vi->i_ino, err, te);
 		ctx = NULL;
 		m = NULL;
-		goto err_out;
+		goto old_bad_out;
 	}
-	ctx = ntfs_attr_get_search_ctx(ni, m);
+	ctx = ntfs_attr_get_search_ctx(base_ni, m);
 	if (unlikely(!ctx)) {
 		ntfs_error(vi->i_sb, "Failed to allocate a search context for "
 				"inode 0x%lx (not enough memory).%s",
 				vi->i_ino, te);
 		err = -ENOMEM;
-		goto err_out;
+		goto old_bad_out;
 	}
 	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
 			CASE_SENSITIVE, 0, NULL, 0, ctx);
 	if (unlikely(err)) {
-		if (err == -ENOENT)
+		if (err == -ENOENT) {
 			ntfs_error(vi->i_sb, "Open attribute is missing from "
 					"mft record.  Inode 0x%lx is corrupt.  "
-					"Run chkdsk.", vi->i_ino);
-		else
+					"Run chkdsk.%s", vi->i_ino, te);
+			err = -EIO;
+		} else
 			ntfs_error(vi->i_sb, "Failed to lookup attribute in "
-					"inode 0x%lx (error code %d).",
-					vi->i_ino, err);
-		goto err_out;
+					"inode 0x%lx (error code %d).%s",
+					vi->i_ino, err, te);
+		goto old_bad_out;
 	}
+	m = ctx->mrec;
 	a = ctx->attr;
-	/* If the size has not changed there is nothing to do. */
-	if (ntfs_attr_size(a) == i_size_read(vi))
-		goto done;
-	// TODO: Implement the truncate...
-	ntfs_error(vi->i_sb, "Inode size has changed but this is not "
-			"implemented yet.  Resetting inode size to old value. "
-			" This is most likely a bug in the ntfs driver!");
-	i_size_write(vi, ntfs_attr_size(a)); 
-done:
+	/*
+	 * The i_size of the vfs inode is the new size for the attribute value.
+	 */
+	new_size = i_size_read(vi);
+	/* The current size of the attribute value is the old size. */
+	old_size = ntfs_attr_size(a);
+	/* Calculate the new allocated size. */
+	if (NInoNonResident(ni))
+		new_alloc_size = (new_size + vol->cluster_size - 1) &
+				~(s64)vol->cluster_size_mask;
+	else
+		new_alloc_size = (new_size + 7) & ~7;
+	/* The current allocated size is the old allocated size. */
+	read_lock_irqsave(&ni->size_lock, flags);
+	old_alloc_size = ni->allocated_size;
+	read_unlock_irqrestore(&ni->size_lock, flags);
+	/*
+	 * The change in the file size.  This will be 0 if no change, >0 if the
+	 * size is growing, and <0 if the size is shrinking.
+	 */
+	size_change = -1;
+	if (new_size - old_size >= 0) {
+		size_change = 1;
+		if (new_size == old_size)
+			size_change = 0;
+	}
+	/* As above for the allocated size. */
+	alloc_change = -1;
+	if (new_alloc_size - old_alloc_size >= 0) {
+		alloc_change = 1;
+		if (new_alloc_size == old_alloc_size)
+			alloc_change = 0;
+	}
+	/*
+	 * If neither the size nor the allocation are being changed there is
+	 * nothing to do.
+	 */
+	if (!size_change && !alloc_change)
+		goto unm_done;
+	/* If the size is changing, check if new size is allowed in $AttrDef. */
+	if (size_change) {
+		err = ntfs_attr_size_bounds_check(vol, ni->type, new_size);
+		if (unlikely(err)) {
+			if (err == -ERANGE) {
+				ntfs_error(vol->sb, "Truncate would cause the "
+						"inode 0x%lx to %simum size "
+						"for its attribute type "
+						"(0x%x).  Aborting truncate.",
+						vi->i_ino,
+						new_size > old_size ? "exceed "
+						"the max" : "go under the min",
+						le32_to_cpu(ni->type));
+				err = -EFBIG;
+			} else {
+				ntfs_error(vol->sb, "Inode 0x%lx has unknown "
+						"attribute type 0x%x.  "
+						"Aborting truncate.",
+						vi->i_ino,
+						le32_to_cpu(ni->type));
+				err = -EIO;
+			}
+			/* Reset the vfs inode size to the old size. */
+			i_size_write(vi, old_size);
+			goto err_out;
+		}
+	}
+	if (NInoCompressed(ni) || NInoEncrypted(ni)) {
+		ntfs_warning(vi->i_sb, "Changes in inode size are not "
+				"supported yet for %s files, ignoring.",
+				NInoCompressed(ni) ? "compressed" :
+				"encrypted");
+		err = -EOPNOTSUPP;
+		goto bad_out;
+	}
+	if (a->non_resident)
+		goto do_non_resident_truncate;
+	BUG_ON(NInoNonResident(ni));
+	/* Resize the attribute record to best fit the new attribute size. */
+	if (new_size < vol->mft_record_size &&
+			!ntfs_resident_attr_value_resize(m, a, new_size)) {
+		unsigned long flags;
+
+		/* The resize succeeded! */
+		flush_dcache_mft_record_page(ctx->ntfs_ino);
+		mark_mft_record_dirty(ctx->ntfs_ino);
+		write_lock_irqsave(&ni->size_lock, flags);
+		/* Update the sizes in the ntfs inode and all is done. */
+		ni->allocated_size = le32_to_cpu(a->length) -
+				le16_to_cpu(a->data.resident.value_offset);
+		/*
+		 * Note ntfs_resident_attr_value_resize() has already done any
+		 * necessary data clearing in the attribute record.  When the
+		 * file is being shrunk vmtruncate() will already have cleared
+		 * the top part of the last partial page, i.e. since this is
+		 * the resident case this is the page with index 0.  However,
+		 * when the file is being expanded, the page cache page data
+		 * between the old data_size, i.e. old_size, and the new_size
+		 * has not been zeroed.  Fortunately, we do not need to zero it
+		 * either since on one hand it will either already be zero due
+		 * to both readpage and writepage clearing partial page data
+		 * beyond i_size in which case there is nothing to do or in the
+		 * case of the file being mmap()ped at the same time, POSIX
+		 * specifies that the behaviour is unspecified thus we do not
+		 * have to do anything.  This means that in our implementation
+		 * in the rare case that the file is mmap()ped and a write
+		 * occured into the mmap()ped region just beyond the file size
+		 * and writepage has not yet been called to write out the page
+		 * (which would clear the area beyond the file size) and we now
+		 * extend the file size to incorporate this dirty region
+		 * outside the file size, a write of the page would result in
+		 * this data being written to disk instead of being cleared.
+		 * Given both POSIX and the Linux mmap(2) man page specify that
+		 * this corner case is undefined, we choose to leave it like
+		 * that as this is much simpler for us as we cannot lock the
+		 * relevant page now since we are holding too many ntfs locks
+		 * which would result in a lock reversal deadlock.
+		 */
+		ni->initialized_size = new_size;
+		write_unlock_irqrestore(&ni->size_lock, flags);
+		goto unm_done;
+	}
+	/* If the above resize failed, this must be an attribute extension. */
+	BUG_ON(size_change < 0);
+	/*
+	 * We have to drop all the locks so we can call
+	 * ntfs_attr_make_non_resident().  This could be optimised by try-
+	 * locking the first page cache page and only if that fails dropping
+	 * the locks, locking the page, and redoing all the locking and
+	 * lookups.  While this would be a huge optimisation, it is not worth
+	 * it as this is definitely a slow code path as it only ever can happen
+	 * once for any given file.
+	 */
 	ntfs_attr_put_search_ctx(ctx);
-	unmap_mft_record(ni);
-	NInoClearTruncateFailed(ni);
-	ntfs_debug("Done.");
-	return 0;
-err_out:
-	if (err != -ENOMEM) {
+	unmap_mft_record(base_ni);
+	up_write(&ni->runlist.lock);
+	/*
+	 * Not enough space in the mft record, try to make the attribute
+	 * non-resident and if successful restart the truncation process.
+	 */
+	err = ntfs_attr_make_non_resident(ni, old_size);
+	if (likely(!err))
+		goto retry_truncate;
+	/*
+	 * Could not make non-resident.  If this is due to this not being
+	 * permitted for this attribute type or there not being enough space,
+	 * try to make other attributes non-resident.  Otherwise fail.
+	 */
+	if (unlikely(err != -EPERM && err != -ENOSPC)) {
+		ntfs_error(vol->sb, "Cannot truncate inode 0x%lx, attribute "
+				"type 0x%x, because the conversion from "
+				"resident to non-resident attribute failed "
+				"with error code %i.", vi->i_ino,
+				(unsigned)le32_to_cpu(ni->type), err);
+		if (err != -ENOMEM)
+			err = -EIO;
+		goto conv_err_out;
+	}
+	/* TODO: Not implemented from here, abort. */
+	if (err == -ENOSPC)
+		ntfs_error(vol->sb, "Not enough space in the mft record/on "
+				"disk for the non-resident attribute value.  "
+				"This case is not implemented yet.");
+	else /* if (err == -EPERM) */
+		ntfs_error(vol->sb, "This attribute type may not be "
+				"non-resident.  This case is not implemented "
+				"yet.");
+	err = -EOPNOTSUPP;
+	goto conv_err_out;
+#if 0
+	// TODO: Attempt to make other attributes non-resident.
+	if (!err)
+		goto do_resident_extend;
+	/*
+	 * Both the attribute list attribute and the standard information
+	 * attribute must remain in the base inode.  Thus, if this is one of
+	 * these attributes, we have to try to move other attributes out into
+	 * extent mft records instead.
+	 */
+	if (ni->type == AT_ATTRIBUTE_LIST ||
+			ni->type == AT_STANDARD_INFORMATION) {
+		// TODO: Attempt to move other attributes into extent mft
+		// records.
+		err = -EOPNOTSUPP;
+		if (!err)
+			goto do_resident_extend;
+		goto err_out;
+	}
+	// TODO: Attempt to move this attribute to an extent mft record, but
+	// only if it is not already the only attribute in an mft record in
+	// which case there would be nothing to gain.
+	err = -EOPNOTSUPP;
+	if (!err)
+		goto do_resident_extend;
+	/* There is nothing we can do to make enough space. )-: */
+	goto err_out;
+#endif
+do_non_resident_truncate:
+	BUG_ON(!NInoNonResident(ni));
+	if (alloc_change < 0) {
+		highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
+		if (highest_vcn > 0 &&
+				old_alloc_size >> vol->cluster_size_bits >
+				highest_vcn + 1) {
+			/*
+			 * This attribute has multiple extents.  Not yet
+			 * supported.
+			 */
+			ntfs_error(vol->sb, "Cannot truncate inode 0x%lx, "
+					"attribute type 0x%x, because the "
+					"attribute is highly fragmented (it "
+					"consists of multiple extents) and "
+					"this case is not implemented yet.",
+					vi->i_ino,
+					(unsigned)le32_to_cpu(ni->type));
+			err = -EOPNOTSUPP;
+			goto bad_out;
+		}
+	}
+	/*
+	 * If the size is shrinking, need to reduce the initialized_size and
+	 * the data_size before reducing the allocation.
+	 */
+	if (size_change < 0) {
+		/*
+		 * Make the valid size smaller (i_size is already up-to-date).
+		 */
+		write_lock_irqsave(&ni->size_lock, flags);
+		if (new_size < ni->initialized_size) {
+			ni->initialized_size = new_size;
+			a->data.non_resident.initialized_size =
+					cpu_to_sle64(new_size);
+		}
+		a->data.non_resident.data_size = cpu_to_sle64(new_size);
+		write_unlock_irqrestore(&ni->size_lock, flags);
+		flush_dcache_mft_record_page(ctx->ntfs_ino);
+		mark_mft_record_dirty(ctx->ntfs_ino);
+		/* If the allocated size is not changing, we are done. */
+		if (!alloc_change)
+			goto unm_done;
+		/*
+		 * If the size is shrinking it makes no sense for the
+		 * allocation to be growing.
+		 */
+		BUG_ON(alloc_change > 0);
+	} else /* if (size_change >= 0) */ {
+		/*
+		 * The file size is growing or staying the same but the
+		 * allocation can be shrinking, growing or staying the same.
+		 */
+		if (alloc_change > 0) {
+			/*
+			 * We need to extend the allocation and possibly update
+			 * the data size.  If we are updating the data size,
+			 * since we are not touching the initialized_size we do
+			 * not need to worry about the actual data on disk.
+			 * And as far as the page cache is concerned, there
+			 * will be no pages beyond the old data size and any
+			 * partial region in the last page between the old and
+			 * new data size (or the end of the page if the new
+			 * data size is outside the page) does not need to be
+			 * modified as explained above for the resident
+			 * attribute truncate case.  To do this, we simply drop
+			 * the locks we hold and leave all the work to our
+			 * friendly helper ntfs_attr_extend_allocation().
+			 */
+			ntfs_attr_put_search_ctx(ctx);
+			unmap_mft_record(base_ni);
+			up_write(&ni->runlist.lock);
+			err = ntfs_attr_extend_allocation(ni, new_size,
+					size_change > 0 ? new_size : -1, -1);
+			/*
+			 * ntfs_attr_extend_allocation() will have done error
+			 * output already.
+			 */
+			goto done;
+		}
+		if (!alloc_change)
+			goto alloc_done;
+	}
+	/* alloc_change < 0 */
+	/* Free the clusters. */
+	nr_freed = ntfs_cluster_free(ni, new_alloc_size >>
+			vol->cluster_size_bits, -1, ctx);
+	m = ctx->mrec;
+	a = ctx->attr;
+	if (unlikely(nr_freed < 0)) {
+		ntfs_error(vol->sb, "Failed to release cluster(s) (error code "
+				"%lli).  Unmount and run chkdsk to recover "
+				"the lost cluster(s).", (long long)nr_freed);
 		NVolSetErrors(vol);
+		nr_freed = 0;
+	}
+	/* Truncate the runlist. */
+	err = ntfs_rl_truncate_nolock(vol, &ni->runlist,
+			new_alloc_size >> vol->cluster_size_bits);
+	/*
+	 * If the runlist truncation failed and/or the search context is no
+	 * longer valid, we cannot resize the attribute record or build the
+	 * mapping pairs array thus we mark the inode bad so that no access to
+	 * the freed clusters can happen.
+	 */
+	if (unlikely(err || IS_ERR(m))) {
+		ntfs_error(vol->sb, "Failed to %s (error code %li).%s",
+				IS_ERR(m) ?
+				"restore attribute search context" :
+				"truncate attribute runlist",
+				IS_ERR(m) ? PTR_ERR(m) : err, es);
+		err = -EIO;
+		goto bad_out;
+	}
+	/* Get the size for the shrunk mapping pairs array for the runlist. */
+	mp_size = ntfs_get_size_for_mapping_pairs(vol, ni->runlist.rl, 0, -1);
+	if (unlikely(mp_size <= 0)) {
+		ntfs_error(vol->sb, "Cannot shrink allocation of inode 0x%lx, "
+				"attribute type 0x%x, because determining the "
+				"size for the mapping pairs failed with error "
+				"code %i.%s", vi->i_ino,
+				(unsigned)le32_to_cpu(ni->type), mp_size, es);
+		err = -EIO;
+		goto bad_out;
+	}
+	/*
+	 * Shrink the attribute record for the new mapping pairs array.  Note,
+	 * this cannot fail since we are making the attribute smaller thus by
+	 * definition there is enough space to do so.
+	 */
+	attr_len = le32_to_cpu(a->length);
+	err = ntfs_attr_record_resize(m, a, mp_size +
+			le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
+	BUG_ON(err);
+	/*
+	 * Generate the mapping pairs array directly into the attribute record.
+	 */
+	err = ntfs_mapping_pairs_build(vol, (u8*)a +
+			le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
+			mp_size, ni->runlist.rl, 0, -1, NULL);
+	if (unlikely(err)) {
+		ntfs_error(vol->sb, "Cannot shrink allocation of inode 0x%lx, "
+				"attribute type 0x%x, because building the "
+				"mapping pairs failed with error code %i.%s",
+				vi->i_ino, (unsigned)le32_to_cpu(ni->type),
+				err, es);
+		err = -EIO;
+		goto bad_out;
+	}
+	/* Update the allocated/compressed size as well as the highest vcn. */
+	a->data.non_resident.highest_vcn = cpu_to_sle64((new_alloc_size >>
+			vol->cluster_size_bits) - 1);
+	write_lock_irqsave(&ni->size_lock, flags);
+	ni->allocated_size = new_alloc_size;
+	a->data.non_resident.allocated_size = cpu_to_sle64(new_alloc_size);
+	if (NInoSparse(ni) || NInoCompressed(ni)) {
+		if (nr_freed) {
+			ni->itype.compressed.size -= nr_freed <<
+					vol->cluster_size_bits;
+			BUG_ON(ni->itype.compressed.size < 0);
+			a->data.non_resident.compressed_size = cpu_to_sle64(
+					ni->itype.compressed.size);
+			vi->i_blocks = ni->itype.compressed.size >> 9;
+		}
+	} else
+		vi->i_blocks = new_alloc_size >> 9;
+	write_unlock_irqrestore(&ni->size_lock, flags);
+	/*
+	 * We have shrunk the allocation.  If this is a shrinking truncate we
+	 * have already dealt with the initialized_size and the data_size above
+	 * and we are done.  If the truncate is only changing the allocation
+	 * and not the data_size, we are also done.  If this is an extending
+	 * truncate, need to extend the data_size now which is ensured by the
+	 * fact that @size_change is positive.
+	 */
+alloc_done:
+	/*
+	 * If the size is growing, need to update it now.  If it is shrinking,
+	 * we have already updated it above (before the allocation change).
+	 */
+	if (size_change > 0)
+		a->data.non_resident.data_size = cpu_to_sle64(new_size);
+	/* Ensure the modified mft record is written out. */
+	flush_dcache_mft_record_page(ctx->ntfs_ino);
+	mark_mft_record_dirty(ctx->ntfs_ino);
+unm_done:
+	ntfs_attr_put_search_ctx(ctx);
+	unmap_mft_record(base_ni);
+	up_write(&ni->runlist.lock);
+done:
+	/* Update the mtime and ctime on the base inode. */
+	inode_update_time(VFS_I(base_ni), 1);
+	if (likely(!err)) {
+		NInoClearTruncateFailed(ni);
+		ntfs_debug("Done.");
+	}
+	return err;
+old_bad_out:
+	old_size = -1;
+bad_out:
+	if (err != -ENOMEM && err != -EOPNOTSUPP) {
 		make_bad_inode(vi);
+		make_bad_inode(VFS_I(base_ni));
+		NVolSetErrors(vol);
 	}
+	if (err != -EOPNOTSUPP)
+		NInoSetTruncateFailed(ni);
+	else if (old_size >= 0)
+		i_size_write(vi, old_size);
+err_out:
 	if (ctx)
 		ntfs_attr_put_search_ctx(ctx);
 	if (m)
-		unmap_mft_record(ni);
-	NInoSetTruncateFailed(ni);
+		unmap_mft_record(base_ni);
+	up_write(&ni->runlist.lock);
+out:
+	ntfs_debug("Failed.  Returning error code %i.", err);
 	return err;
+conv_err_out:
+	if (err != -ENOMEM && err != -EOPNOTSUPP) {
+		make_bad_inode(vi);
+		make_bad_inode(VFS_I(base_ni));
+		NVolSetErrors(vol);
+	}
+	if (err != -EOPNOTSUPP)
+		NInoSetTruncateFailed(ni);
+	else
+		i_size_write(vi, old_size);
+	goto out;
 }
 
 /**
@@ -2406,8 +2845,7 @@ int ntfs_setattr(struct dentry *dentry, struct iattr *attr)
 
 	err = inode_change_ok(vi, attr);
 	if (err)
-		return err;
-
+		goto out;
 	/* We do not support NTFS ACLs yet. */
 	if (ia_valid & (ATTR_UID | ATTR_GID | ATTR_MODE)) {
 		ntfs_warning(vi->i_sb, "Changes in user/group/mode are not "
@@ -2415,14 +2853,22 @@ int ntfs_setattr(struct dentry *dentry, struct iattr *attr)
 		err = -EOPNOTSUPP;
 		goto out;
 	}
-
 	if (ia_valid & ATTR_SIZE) {
 		if (attr->ia_size != i_size_read(vi)) {
-			ntfs_warning(vi->i_sb, "Changes in inode size are not "
-					"supported yet, ignoring.");
-			err = -EOPNOTSUPP;
-			// TODO: Implement...
-			// err = vmtruncate(vi, attr->ia_size);
+			ntfs_inode *ni = NTFS_I(vi);
+			/*
+			 * FIXME: For now we do not support resizing of
+			 * compressed or encrypted files yet.
+			 */
+			if (NInoCompressed(ni) || NInoEncrypted(ni)) {
+				ntfs_warning(vi->i_sb, "Changes in inode size "
+						"are not supported yet for "
+						"%s files, ignoring.",
+						NInoCompressed(ni) ?
+						"compressed" : "encrypted");
+				err = -EOPNOTSUPP;
+			} else
+				err = vmtruncate(vi, attr->ia_size);
 			if (err || ia_valid == ATTR_SIZE)
 				goto out;
 		} else {
@@ -2430,16 +2876,18 @@ int ntfs_setattr(struct dentry *dentry, struct iattr *attr)
 			 * We skipped the truncate but must still update
 			 * timestamps.
 			 */
-			ia_valid |= ATTR_MTIME|ATTR_CTIME;
+			ia_valid |= ATTR_MTIME | ATTR_CTIME;
 		}
 	}
-
 	if (ia_valid & ATTR_ATIME)
-		vi->i_atime = attr->ia_atime;
+		vi->i_atime = timespec_trunc(attr->ia_atime,
+				vi->i_sb->s_time_gran);
 	if (ia_valid & ATTR_MTIME)
-		vi->i_mtime = attr->ia_mtime;
+		vi->i_mtime = timespec_trunc(attr->ia_mtime,
+				vi->i_sb->s_time_gran);
 	if (ia_valid & ATTR_CTIME)
-		vi->i_ctime = attr->ia_ctime;
+		vi->i_ctime = timespec_trunc(attr->ia_ctime,
+				vi->i_sb->s_time_gran);
 	mark_inode_dirty(vi);
 out:
 	return err;
diff --git a/fs/ntfs/layout.h b/fs/ntfs/layout.h
index 609ad1728ce4..f5678d5d7919 100644
--- a/fs/ntfs/layout.h
+++ b/fs/ntfs/layout.h
@@ -123,7 +123,7 @@ enum {
 	magic_RCRD = const_cpu_to_le32(0x44524352), /* Log record page. */
 
 	/* Found in $LogFile/$DATA.  (May be found in $MFT/$DATA, also?) */
-	magic_CHKD = const_cpu_to_le32(0x424b4843), /* Modified by chkdsk. */
+	magic_CHKD = const_cpu_to_le32(0x444b4843), /* Modified by chkdsk. */
 
 	/* Found in all ntfs record containing records. */
 	magic_BAAD = const_cpu_to_le32(0x44414142), /* Failed multi sector
@@ -308,10 +308,8 @@ typedef le16 MFT_RECORD_FLAGS;
  * The _LE versions are to be applied on little endian MFT_REFs.
  * Note: The _LE versions will return a CPU endian formatted value!
  */
-typedef enum {
-	MFT_REF_MASK_CPU	= 0x0000ffffffffffffULL,
-	MFT_REF_MASK_LE		= const_cpu_to_le64(0x0000ffffffffffffULL),
-} MFT_REF_CONSTS;
+#define MFT_REF_MASK_CPU 0x0000ffffffffffffULL
+#define MFT_REF_MASK_LE const_cpu_to_le64(MFT_REF_MASK_CPU)
 
 typedef u64 MFT_REF;
 typedef le64 leMFT_REF;
@@ -1023,10 +1021,17 @@ enum {
 	FILE_NAME_POSIX		= 0x00,
 	/* This is the largest namespace. It is case sensitive and allows all
 	   Unicode characters except for: '\0' and '/'.  Beware that in
-	   WinNT/2k files which eg have the same name except for their case
-	   will not be distinguished by the standard utilities and thus a "del
-	   filename" will delete both "filename" and "fileName" without
-	   warning. */
+	   WinNT/2k/2003 by default files which eg have the same name except
+	   for their case will not be distinguished by the standard utilities
+	   and thus a "del filename" will delete both "filename" and "fileName"
+	   without warning.  However if for example Services For Unix (SFU) are
+	   installed and the case sensitive option was enabled at installation
+	   time, then you can create/access/delete such files.
+	   Note that even SFU places restrictions on the filenames beyond the
+	   '\0' and '/' and in particular the following set of characters is
+	   not allowed: '"', '/', '<', '>', '\'.  All other characters,
+	   including the ones no allowed in WIN32 namespace are allowed.
+	   Tested with SFU 3.5 (this is now free) running on Windows XP. */
 	FILE_NAME_WIN32		= 0x01,
 	/* The standard WinNT/2k NTFS long filenames. Case insensitive.  All
 	   Unicode chars except: '\0', '"', '*', '/', ':', '<', '>', '?', '\',
@@ -2369,7 +2374,9 @@ typedef struct {
  * Extended attribute flags (8-bit).
  */
 enum {
-	NEED_EA	= 0x80
+	NEED_EA	= 0x80		/* If set the file to which the EA belongs
+				   cannot be interpreted without understanding
+				   the associates extended attributes. */
 } __attribute__ ((__packed__));
 
 typedef u8 EA_FLAGS;
@@ -2377,20 +2384,20 @@ typedef u8 EA_FLAGS;
 /*
  * Attribute: Extended attribute (EA) (0xe0).
  *
- * NOTE: Always non-resident. (Is this true?)
+ * NOTE: Can be resident or non-resident.
  *
  * Like the attribute list and the index buffer list, the EA attribute value is
  * a sequence of EA_ATTR variable length records.
- *
- * FIXME: It appears weird that the EA name is not unicode. Is it true?
  */
 typedef struct {
 	le32 next_entry_offset;	/* Offset to the next EA_ATTR. */
 	EA_FLAGS flags;		/* Flags describing the EA. */
-	u8 ea_name_length;	/* Length of the name of the EA in bytes. */
+	u8 ea_name_length;	/* Length of the name of the EA in bytes
+				   excluding the '\0' byte terminator. */
 	le16 ea_value_length;	/* Byte size of the EA's value. */
-	u8 ea_name[0];		/* Name of the EA. */
-	u8 ea_value[0];		/* The value of the EA. Immediately follows
+	u8 ea_name[0];		/* Name of the EA.  Note this is ASCII, not
+				   Unicode and it is zero terminated. */
+	u8 ea_value[0];		/* The value of the EA.  Immediately follows
 				   the name. */
 } __attribute__ ((__packed__)) EA_ATTR;
 
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
index a4bc07616e5d..29cabf93d2d2 100644
--- a/fs/ntfs/lcnalloc.c
+++ b/fs/ntfs/lcnalloc.c
@@ -54,6 +54,8 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
 	int ret = 0;
 
 	ntfs_debug("Entering.");
+	if (!rl)
+		return 0;
 	for (; rl->length; rl++) {
 		int err;
 
@@ -74,6 +76,7 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  * @count:	number of clusters to allocate
  * @start_lcn:	starting lcn at which to allocate the clusters (or -1 if none)
  * @zone:	zone from which to allocate the clusters
+ * @is_extension:	if TRUE, this is an attribute extension
  *
  * Allocate @count clusters preferably starting at cluster @start_lcn or at the
  * current allocator position if @start_lcn is -1, on the mounted ntfs volume
@@ -84,6 +87,13 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  * @start_vcn specifies the vcn of the first allocated cluster.  This makes
  * merging the resulting runlist with the old runlist easier.
  *
+ * If @is_extension is TRUE, the caller is allocating clusters to extend an
+ * attribute and if it is FALSE, the caller is allocating clusters to fill a
+ * hole in an attribute.  Practically the difference is that if @is_extension
+ * is TRUE the returned runlist will be terminated with LCN_ENOENT and if
+ * @is_extension is FALSE the runlist will be terminated with
+ * LCN_RL_NOT_MAPPED.
+ *
  * You need to check the return value with IS_ERR().  If this is false, the
  * function was successful and the return value is a runlist describing the
  * allocated cluster(s).  If IS_ERR() is true, the function failed and
@@ -135,7 +145,8 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  */
 runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
 		const s64 count, const LCN start_lcn,
-		const NTFS_CLUSTER_ALLOCATION_ZONES zone)
+		const NTFS_CLUSTER_ALLOCATION_ZONES zone,
+		const BOOL is_extension)
 {
 	LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
 	LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
@@ -163,17 +174,9 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
 	BUG_ON(zone < FIRST_ZONE);
 	BUG_ON(zone > LAST_ZONE);
 
-	/* Return empty runlist if @count == 0 */
-	// FIXME: Do we want to just return NULL instead? (AIA)
-	if (!count) {
-		rl = ntfs_malloc_nofs(PAGE_SIZE);
-		if (!rl)
-			return ERR_PTR(-ENOMEM);
-		rl[0].vcn = start_vcn;
-		rl[0].lcn = LCN_RL_NOT_MAPPED;
-		rl[0].length = 0;
-		return rl;
-	}
+	/* Return NULL if @count is zero. */
+	if (!count)
+		return NULL;
 	/* Take the lcnbmp lock for writing. */
 	down_write(&vol->lcnbmp_lock);
 	/*
@@ -316,7 +319,7 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
 				continue;
 			}
 			bit = 1 << (lcn & 7);
-			ntfs_debug("bit %i.", bit);
+			ntfs_debug("bit 0x%x.", bit);
 			/* If the bit is already set, go onto the next one. */
 			if (*byte & bit) {
 				lcn++;
@@ -735,7 +738,7 @@ out:
 	/* Add runlist terminator element. */
 	if (likely(rl)) {
 		rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
-		rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
+		rl[rlpos].lcn = is_extension ? LCN_ENOENT : LCN_RL_NOT_MAPPED;
 		rl[rlpos].length = 0;
 	}
 	if (likely(page && !IS_ERR(page))) {
@@ -785,52 +788,78 @@ out:
 
 /**
  * __ntfs_cluster_free - free clusters on an ntfs volume
- * @vi:		vfs inode whose runlist describes the clusters to free
- * @start_vcn:	vcn in the runlist of @vi at which to start freeing clusters
+ * @ni:		ntfs inode whose runlist describes the clusters to free
+ * @start_vcn:	vcn in the runlist of @ni at which to start freeing clusters
  * @count:	number of clusters to free or -1 for all clusters
- * @is_rollback:	if TRUE this is a rollback operation
+ * @ctx:	active attribute search context if present or NULL if not
+ * @is_rollback:	true if this is a rollback operation
  *
  * Free @count clusters starting at the cluster @start_vcn in the runlist
- * described by the vfs inode @vi.
+ * described by the vfs inode @ni.
  *
  * If @count is -1, all clusters from @start_vcn to the end of the runlist are
  * deallocated.  Thus, to completely free all clusters in a runlist, use
  * @start_vcn = 0 and @count = -1.
  *
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record.  This is needed when __ntfs_cluster_free() encounters unmapped
+ * runlist fragments and allows their mapping.  If you do not have the mft
+ * record mapped, you can specify @ctx as NULL and __ntfs_cluster_free() will
+ * perform the necessary mapping and unmapping.
+ *
+ * Note, __ntfs_cluster_free() saves the state of @ctx on entry and restores it
+ * before returning.  Thus, @ctx will be left pointing to the same attribute on
+ * return as on entry.  However, the actual pointers in @ctx may point to
+ * different memory locations on return, so you must remember to reset any
+ * cached pointers from the @ctx, i.e. after the call to __ntfs_cluster_free(),
+ * you will probably want to do:
+ *	m = ctx->mrec;
+ *	a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ *
  * @is_rollback should always be FALSE, it is for internal use to rollback
  * errors.  You probably want to use ntfs_cluster_free() instead.
  *
- * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
- * has to deal with it later.
+ * Note, __ntfs_cluster_free() does not modify the runlist, so you have to
+ * remove from the runlist or mark sparse the freed runs later.
  *
  * Return the number of deallocated clusters (not counting sparse ones) on
  * success and -errno on error.
  *
- * Locking: - The runlist described by @vi must be unlocked on entry and is
- *	      unlocked on return.
- *	    - This function takes the runlist lock of @vi for reading and
- *	      sometimes for writing and sometimes modifies the runlist.
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ *	    returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx
+ *	    is no longer valid, i.e. you need to either call
+ *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ *	    why the mapping of the old inode failed.
+ *
+ * Locking: - The runlist described by @ni must be locked for writing on entry
+ *	      and is locked on return.  Note the runlist may be modified when
+ *	      needed runlist fragments need to be mapped.
  *	    - The volume lcn bitmap must be unlocked on entry and is unlocked
  *	      on return.
  *	    - This function takes the volume lcn bitmap lock for writing and
  *	      modifies the bitmap contents.
+ *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ *	      entry and it will be left unmapped on return.
+ *	    - If @ctx is not NULL, the base mft record must be mapped on entry
+ *	      and it will be left mapped on return.
  */
-s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
-		const BOOL is_rollback)
+s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
+		ntfs_attr_search_ctx *ctx, const BOOL is_rollback)
 {
 	s64 delta, to_free, total_freed, real_freed;
-	ntfs_inode *ni;
 	ntfs_volume *vol;
 	struct inode *lcnbmp_vi;
 	runlist_element *rl;
 	int err;
 
-	BUG_ON(!vi);
+	BUG_ON(!ni);
 	ntfs_debug("Entering for i_ino 0x%lx, start_vcn 0x%llx, count "
-			"0x%llx.%s", vi->i_ino, (unsigned long long)start_vcn,
+			"0x%llx.%s", ni->mft_no, (unsigned long long)start_vcn,
 			(unsigned long long)count,
 			is_rollback ? " (rollback)" : "");
-	ni = NTFS_I(vi);
 	vol = ni->vol;
 	lcnbmp_vi = vol->lcnbmp_ino;
 	BUG_ON(!lcnbmp_vi);
@@ -848,8 +877,7 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
 
 	total_freed = real_freed = 0;
 
-	down_read(&ni->runlist.lock);
-	rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, FALSE);
+	rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, ctx);
 	if (IS_ERR(rl)) {
 		if (!is_rollback)
 			ntfs_error(vol->sb, "Failed to find first runlist "
@@ -903,7 +931,7 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
 
 			/* Attempt to map runlist. */
 			vcn = rl->vcn;
-			rl = ntfs_attr_find_vcn_nolock(ni, vcn, FALSE);
+			rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx);
 			if (IS_ERR(rl)) {
 				err = PTR_ERR(rl);
 				if (!is_rollback)
@@ -950,7 +978,6 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
 		/* Update the total done clusters. */
 		total_freed += to_free;
 	}
-	up_read(&ni->runlist.lock);
 	if (likely(!is_rollback))
 		up_write(&vol->lcnbmp_lock);
 
@@ -960,7 +987,6 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
 	ntfs_debug("Done.");
 	return real_freed;
 err_out:
-	up_read(&ni->runlist.lock);
 	if (is_rollback)
 		return err;
 	/* If no real clusters were freed, no need to rollback. */
@@ -973,7 +999,7 @@ err_out:
 	 * If rollback fails, set the volume errors flag, emit an error
 	 * message, and return the error code.
 	 */
-	delta = __ntfs_cluster_free(vi, start_vcn, total_freed, TRUE);
+	delta = __ntfs_cluster_free(ni, start_vcn, total_freed, ctx, TRUE);
 	if (delta < 0) {
 		ntfs_error(vol->sb, "Failed to rollback (error %i).  Leaving "
 				"inconsistent metadata!  Unmount and run "
diff --git a/fs/ntfs/lcnalloc.h b/fs/ntfs/lcnalloc.h
index 4cac1c024af6..72cbca7003b2 100644
--- a/fs/ntfs/lcnalloc.h
+++ b/fs/ntfs/lcnalloc.h
@@ -2,7 +2,7 @@
  * lcnalloc.h - Exports for NTFS kernel cluster (de)allocation.  Part of the
  *		Linux-NTFS project.
  *
- * Copyright (c) 2004 Anton Altaparmakov
+ * Copyright (c) 2004-2005 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -27,7 +27,9 @@
 
 #include <linux/fs.h>
 
+#include "attrib.h"
 #include "types.h"
+#include "inode.h"
 #include "runlist.h"
 #include "volume.h"
 
@@ -40,43 +42,72 @@ typedef enum {
 
 extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol,
 		const VCN start_vcn, const s64 count, const LCN start_lcn,
-		const NTFS_CLUSTER_ALLOCATION_ZONES zone);
+		const NTFS_CLUSTER_ALLOCATION_ZONES zone,
+		const BOOL is_extension);
 
-extern s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
-		s64 count, const BOOL is_rollback);
+extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
+		s64 count, ntfs_attr_search_ctx *ctx, const BOOL is_rollback);
 
 /**
  * ntfs_cluster_free - free clusters on an ntfs volume
- * @vi:		vfs inode whose runlist describes the clusters to free
- * @start_vcn:	vcn in the runlist of @vi at which to start freeing clusters
+ * @ni:		ntfs inode whose runlist describes the clusters to free
+ * @start_vcn:	vcn in the runlist of @ni at which to start freeing clusters
  * @count:	number of clusters to free or -1 for all clusters
+ * @ctx:	active attribute search context if present or NULL if not
  *
  * Free @count clusters starting at the cluster @start_vcn in the runlist
- * described by the vfs inode @vi.
+ * described by the ntfs inode @ni.
  *
  * If @count is -1, all clusters from @start_vcn to the end of the runlist are
  * deallocated.  Thus, to completely free all clusters in a runlist, use
  * @start_vcn = 0 and @count = -1.
  *
- * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
- * has to deal with it later.
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record.  This is needed when ntfs_cluster_free() encounters unmapped runlist
+ * fragments and allows their mapping.  If you do not have the mft record
+ * mapped, you can specify @ctx as NULL and ntfs_cluster_free() will perform
+ * the necessary mapping and unmapping.
+ *
+ * Note, ntfs_cluster_free() saves the state of @ctx on entry and restores it
+ * before returning.  Thus, @ctx will be left pointing to the same attribute on
+ * return as on entry.  However, the actual pointers in @ctx may point to
+ * different memory locations on return, so you must remember to reset any
+ * cached pointers from the @ctx, i.e. after the call to ntfs_cluster_free(),
+ * you will probably want to do:
+ *	m = ctx->mrec;
+ *	a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ *
+ * Note, ntfs_cluster_free() does not modify the runlist, so you have to remove
+ * from the runlist or mark sparse the freed runs later.
  *
  * Return the number of deallocated clusters (not counting sparse ones) on
  * success and -errno on error.
  *
- * Locking: - The runlist described by @vi must be unlocked on entry and is
- *	      unlocked on return.
- *	    - This function takes the runlist lock of @vi for reading and
- *	      sometimes for writing and sometimes modifies the runlist.
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ *	    returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx
+ *	    is no longer valid, i.e. you need to either call
+ *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ *	    why the mapping of the old inode failed.
+ *
+ * Locking: - The runlist described by @ni must be locked for writing on entry
+ *	      and is locked on return.  Note the runlist may be modified when
+ *	      needed runlist fragments need to be mapped.
  *	    - The volume lcn bitmap must be unlocked on entry and is unlocked
  *	      on return.
  *	    - This function takes the volume lcn bitmap lock for writing and
  *	      modifies the bitmap contents.
+ *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ *	      entry and it will be left unmapped on return.
+ *	    - If @ctx is not NULL, the base mft record must be mapped on entry
+ *	      and it will be left mapped on return.
  */
-static inline s64 ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
-		s64 count)
+static inline s64 ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
+		s64 count, ntfs_attr_search_ctx *ctx)
 {
-	return __ntfs_cluster_free(vi, start_vcn, count, FALSE);
+	return __ntfs_cluster_free(ni, start_vcn, count, ctx, FALSE);
 }
 
 extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
@@ -93,8 +124,10 @@ extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  *
  * Return 0 on success and -errno on error.
  *
- * Locking: This function takes the volume lcn bitmap lock for writing and
- *	    modifies the bitmap contents.
+ * Locking: - This function takes the volume lcn bitmap lock for writing and
+ *	      modifies the bitmap contents.
+ *	    - The caller must have locked the runlist @rl for reading or
+ *	      writing.
  */
 static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol,
 		const runlist_element *rl)
diff --git a/fs/ntfs/logfile.c b/fs/ntfs/logfile.c
index 8edb8e20fb08..0fd70295cca6 100644
--- a/fs/ntfs/logfile.c
+++ b/fs/ntfs/logfile.c
@@ -51,7 +51,8 @@ static BOOL ntfs_check_restart_page_header(struct inode *vi,
 		RESTART_PAGE_HEADER *rp, s64 pos)
 {
 	u32 logfile_system_page_size, logfile_log_page_size;
-	u16 usa_count, usa_ofs, usa_end, ra_ofs;
+	u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
+	BOOL have_usa = TRUE;
 
 	ntfs_debug("Entering.");
 	/*
@@ -86,6 +87,14 @@ static BOOL ntfs_check_restart_page_header(struct inode *vi,
 				(int)sle16_to_cpu(rp->minor_ver));
 		return FALSE;
 	}
+	/*
+	 * If chkdsk has been run the restart page may not be protected by an
+	 * update sequence array.
+	 */
+	if (ntfs_is_chkd_record(rp->magic) && !le16_to_cpu(rp->usa_count)) {
+		have_usa = FALSE;
+		goto skip_usa_checks;
+	}
 	/* Verify the size of the update sequence array. */
 	usa_count = 1 + (logfile_system_page_size >> NTFS_BLOCK_SIZE_BITS);
 	if (usa_count != le16_to_cpu(rp->usa_count)) {
@@ -102,6 +111,7 @@ static BOOL ntfs_check_restart_page_header(struct inode *vi,
 				"inconsistent update sequence array offset.");
 		return FALSE;
 	}
+skip_usa_checks:
 	/*
 	 * Verify the position of the restart area.  It must be:
 	 *	- aligned to 8-byte boundary,
@@ -109,7 +119,8 @@ static BOOL ntfs_check_restart_page_header(struct inode *vi,
 	 *	- within the system page size.
 	 */
 	ra_ofs = le16_to_cpu(rp->restart_area_offset);
-	if (ra_ofs & 7 || ra_ofs < usa_end ||
+	if (ra_ofs & 7 || (have_usa ? ra_ofs < usa_end :
+			ra_ofs < sizeof(RESTART_PAGE_HEADER)) ||
 			ra_ofs > logfile_system_page_size) {
 		ntfs_error(vi->i_sb, "$LogFile restart page specifies "
 				"inconsistent restart area offset.");
@@ -121,7 +132,7 @@ static BOOL ntfs_check_restart_page_header(struct inode *vi,
 	 */
 	if (!ntfs_is_chkd_record(rp->magic) && sle64_to_cpu(rp->chkdsk_lsn)) {
 		ntfs_error(vi->i_sb, "$LogFile restart page is not modified "
-				"chkdsk but a chkdsk LSN is specified.");
+				"by chkdsk but a chkdsk LSN is specified.");
 		return FALSE;
 	}
 	ntfs_debug("Done.");
@@ -312,10 +323,12 @@ err_out:
  * @vi:		$LogFile inode to which the restart page belongs
  * @rp:		restart page to check
  * @pos:	position in @vi at which the restart page resides
- * @wrp:	copy of the multi sector transfer deprotected restart page
+ * @wrp:	[OUT] copy of the multi sector transfer deprotected restart page
+ * @lsn:	[OUT] set to the current logfile lsn on success
  *
- * Check the restart page @rp for consistency and return TRUE if it is
- * consistent and FALSE otherwise.
+ * Check the restart page @rp for consistency and return 0 if it is consistent
+ * and -errno otherwise.  The restart page may have been modified by chkdsk in
+ * which case its magic is CHKD instead of RSTR.
  *
  * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
  * require the full restart page.
@@ -323,25 +336,33 @@ err_out:
  * If @wrp is not NULL, on success, *@wrp will point to a buffer containing a
  * copy of the complete multi sector transfer deprotected page.  On failure,
  * *@wrp is undefined.
+ *
+ * Simillarly, if @lsn is not NULL, on succes *@lsn will be set to the current
+ * logfile lsn according to this restart page.  On failure, *@lsn is undefined.
+ *
+ * The following error codes are defined:
+ *	-EINVAL	- The restart page is inconsistent.
+ *	-ENOMEM	- Not enough memory to load the restart page.
+ *	-EIO	- Failed to reading from $LogFile.
  */
-static BOOL ntfs_check_and_load_restart_page(struct inode *vi,
-		RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp)
+static int ntfs_check_and_load_restart_page(struct inode *vi,
+		RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp,
+		LSN *lsn)
 {
 	RESTART_AREA *ra;
 	RESTART_PAGE_HEADER *trp;
-	int size;
-	BOOL ret;
+	int size, err;
 
 	ntfs_debug("Entering.");
 	/* Check the restart page header for consistency. */
 	if (!ntfs_check_restart_page_header(vi, rp, pos)) {
 		/* Error output already done inside the function. */
-		return FALSE;
+		return -EINVAL;
 	}
 	/* Check the restart area for consistency. */
 	if (!ntfs_check_restart_area(vi, rp)) {
 		/* Error output already done inside the function. */
-		return FALSE;
+		return -EINVAL;
 	}
 	ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
 	/*
@@ -352,7 +373,7 @@ static BOOL ntfs_check_and_load_restart_page(struct inode *vi,
 	if (!trp) {
 		ntfs_error(vi->i_sb, "Failed to allocate memory for $LogFile "
 				"restart page buffer.");
-		return FALSE;
+		return -ENOMEM;
 	}
 	/*
 	 * Read the whole of the restart page into the buffer.  If it fits
@@ -379,6 +400,9 @@ static BOOL ntfs_check_and_load_restart_page(struct inode *vi,
 			if (IS_ERR(page)) {
 				ntfs_error(vi->i_sb, "Error mapping $LogFile "
 						"page (index %lu).", idx);
+				err = PTR_ERR(page);
+				if (err != -EIO && err != -ENOMEM)
+					err = -EIO;
 				goto err_out;
 			}
 			size = min_t(int, to_read, PAGE_CACHE_SIZE);
@@ -389,32 +413,64 @@ static BOOL ntfs_check_and_load_restart_page(struct inode *vi,
 			idx++;
 		} while (to_read > 0);
 	}
-	/* Perform the multi sector transfer deprotection on the buffer. */
-	if (post_read_mst_fixup((NTFS_RECORD*)trp,
+	/*
+	 * Perform the multi sector transfer deprotection on the buffer if the
+	 * restart page is protected.
+	 */
+	if ((!ntfs_is_chkd_record(trp->magic) || le16_to_cpu(trp->usa_count))
+			&& post_read_mst_fixup((NTFS_RECORD*)trp,
 			le32_to_cpu(rp->system_page_size))) {
-		ntfs_error(vi->i_sb, "Multi sector transfer error detected in "
-				"$LogFile restart page.");
-		goto err_out;
+		/*
+		 * A multi sector tranfer error was detected.  We only need to
+		 * abort if the restart page contents exceed the multi sector
+		 * transfer fixup of the first sector.
+		 */
+		if (le16_to_cpu(rp->restart_area_offset) +
+				le16_to_cpu(ra->restart_area_length) >
+				NTFS_BLOCK_SIZE - sizeof(u16)) {
+			ntfs_error(vi->i_sb, "Multi sector transfer error "
+					"detected in $LogFile restart page.");
+			err = -EINVAL;
+			goto err_out;
+		}
+	}
+	/*
+	 * If the restart page is modified by chkdsk or there are no active
+	 * logfile clients, the logfile is consistent.  Otherwise, need to
+	 * check the log client records for consistency, too.
+	 */
+	err = 0;
+	if (ntfs_is_rstr_record(rp->magic) &&
+			ra->client_in_use_list != LOGFILE_NO_CLIENT) {
+		if (!ntfs_check_log_client_array(vi, trp)) {
+			err = -EINVAL;
+			goto err_out;
+		}
+	}
+	if (lsn) {
+		if (ntfs_is_rstr_record(rp->magic))
+			*lsn = sle64_to_cpu(ra->current_lsn);
+		else /* if (ntfs_is_chkd_record(rp->magic)) */
+			*lsn = sle64_to_cpu(rp->chkdsk_lsn);
 	}
-	/* Check the log client records for consistency. */
-	ret = ntfs_check_log_client_array(vi, trp);
-	if (ret && wrp)
-		*wrp = trp;
-	else
-		ntfs_free(trp);
 	ntfs_debug("Done.");
-	return ret;
+	if (wrp)
+		*wrp = trp;
+	else {
 err_out:
-	ntfs_free(trp);
-	return FALSE;
+		ntfs_free(trp);
+	}
+	return err;
 }
 
 /**
  * ntfs_check_logfile - check the journal for consistency
  * @log_vi:	struct inode of loaded journal $LogFile to check
+ * @rp:		[OUT] on success this is a copy of the current restart page
  *
  * Check the $LogFile journal for consistency and return TRUE if it is
- * consistent and FALSE if not.
+ * consistent and FALSE if not.  On success, the current restart page is
+ * returned in *@rp.  Caller must call ntfs_free(*@rp) when finished with it.
  *
  * At present we only check the two restart pages and ignore the log record
  * pages.
@@ -424,19 +480,18 @@ err_out:
  * if the $LogFile was created on a system with a different page size to ours
  * yet and mst deprotection would fail if our page size is smaller.
  */
-BOOL ntfs_check_logfile(struct inode *log_vi)
+BOOL ntfs_check_logfile(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
 {
-	s64 size, pos, rstr1_pos, rstr2_pos;
+	s64 size, pos;
+	LSN rstr1_lsn, rstr2_lsn;
 	ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
 	struct address_space *mapping = log_vi->i_mapping;
 	struct page *page = NULL;
 	u8 *kaddr = NULL;
 	RESTART_PAGE_HEADER *rstr1_ph = NULL;
 	RESTART_PAGE_HEADER *rstr2_ph = NULL;
-	int log_page_size, log_page_mask, ofs;
+	int log_page_size, log_page_mask, err;
 	BOOL logfile_is_empty = TRUE;
-	BOOL rstr1_found = FALSE;
-	BOOL rstr2_found = FALSE;
 	u8 log_page_bits;
 
 	ntfs_debug("Entering.");
@@ -491,7 +546,7 @@ BOOL ntfs_check_logfile(struct inode *log_vi)
 			if (IS_ERR(page)) {
 				ntfs_error(vol->sb, "Error mapping $LogFile "
 						"page (index %lu).", idx);
-				return FALSE;
+				goto err_out;
 			}
 		}
 		kaddr = (u8*)page_address(page) + (pos & ~PAGE_CACHE_MASK);
@@ -510,99 +565,100 @@ BOOL ntfs_check_logfile(struct inode *log_vi)
 		 */
 		if (ntfs_is_rcrd_recordp((le32*)kaddr))
 			break;
-		/*
-		 * A modified by chkdsk restart page means we cannot handle
-		 * this log file.
-		 */
-		if (ntfs_is_chkd_recordp((le32*)kaddr)) {
-			ntfs_error(vol->sb, "$LogFile has been modified by "
-					"chkdsk.  Mount this volume in "
-					"Windows.");
-			goto err_out;
-		}
-		/* If not a restart page, continue. */
-		if (!ntfs_is_rstr_recordp((le32*)kaddr)) {
-			/* Skip to the minimum page size for the next one. */
+		/* If not a (modified by chkdsk) restart page, continue. */
+		if (!ntfs_is_rstr_recordp((le32*)kaddr) &&
+				!ntfs_is_chkd_recordp((le32*)kaddr)) {
 			if (!pos)
 				pos = NTFS_BLOCK_SIZE >> 1;
 			continue;
 		}
-		/* We now know we have a restart page. */
-		if (!pos) {
-			rstr1_found = TRUE;
-			rstr1_pos = pos;
-		} else {
-			if (rstr2_found) {
-				ntfs_error(vol->sb, "Found more than two "
-						"restart pages in $LogFile.");
-				goto err_out;
-			}
-			rstr2_found = TRUE;
-			rstr2_pos = pos;
-		}
 		/*
-		 * Check the restart page for consistency and get a copy of the
-		 * complete multi sector transfer deprotected restart page.
+		 * Check the (modified by chkdsk) restart page for consistency
+		 * and get a copy of the complete multi sector transfer
+		 * deprotected restart page.
 		 */
-		if (!ntfs_check_and_load_restart_page(log_vi,
+		err = ntfs_check_and_load_restart_page(log_vi,
 				(RESTART_PAGE_HEADER*)kaddr, pos,
-				!pos ? &rstr1_ph : &rstr2_ph)) {
-			/* Error output already done inside the function. */
-			goto err_out;
+				!rstr1_ph ? &rstr1_ph : &rstr2_ph,
+				!rstr1_ph ? &rstr1_lsn : &rstr2_lsn);
+		if (!err) {
+			/*
+			 * If we have now found the first (modified by chkdsk)
+			 * restart page, continue looking for the second one.
+			 */
+			if (!pos) {
+				pos = NTFS_BLOCK_SIZE >> 1;
+				continue;
+			}
+			/*
+			 * We have now found the second (modified by chkdsk)
+			 * restart page, so we can stop looking.
+			 */
+			break;
 		}
 		/*
-		 * We have a valid restart page.  The next one must be after
-		 * a whole system page size as specified by the valid restart
-		 * page.
+		 * Error output already done inside the function.  Note, we do
+		 * not abort if the restart page was invalid as we might still
+		 * find a valid one further in the file.
 		 */
+		if (err != -EINVAL) {
+			ntfs_unmap_page(page);
+			goto err_out;
+		}
+		/* Continue looking. */
 		if (!pos)
-			pos = le32_to_cpu(rstr1_ph->system_page_size) >> 1;
+			pos = NTFS_BLOCK_SIZE >> 1;
 	}
-	if (page) {
+	if (page)
 		ntfs_unmap_page(page);
-		page = NULL;
-	}
 	if (logfile_is_empty) {
 		NVolSetLogFileEmpty(vol);
 is_empty:
 		ntfs_debug("Done.  ($LogFile is empty.)");
 		return TRUE;
 	}
-	if (!rstr1_found || !rstr2_found) {
-		ntfs_error(vol->sb, "Did not find two restart pages in "
-				"$LogFile.");
-		goto err_out;
+	if (!rstr1_ph) {
+		BUG_ON(rstr2_ph);
+		ntfs_error(vol->sb, "Did not find any restart pages in "
+				"$LogFile and it was not empty.");
+		return FALSE;
+	}
+	/* If both restart pages were found, use the more recent one. */
+	if (rstr2_ph) {
+		/*
+		 * If the second restart area is more recent, switch to it.
+		 * Otherwise just throw it away.
+		 */
+		if (rstr2_lsn > rstr1_lsn) {
+			ntfs_debug("Using second restart page as it is more "
+					"recent.");
+			ntfs_free(rstr1_ph);
+			rstr1_ph = rstr2_ph;
+			/* rstr1_lsn = rstr2_lsn; */
+		} else {
+			ntfs_debug("Using first restart page as it is more "
+					"recent.");
+			ntfs_free(rstr2_ph);
+		}
+		rstr2_ph = NULL;
 	}
-	/*
-	 * The two restart areas must be identical except for the update
-	 * sequence number.
-	 */
-	ofs = le16_to_cpu(rstr1_ph->usa_ofs);
-	if (memcmp(rstr1_ph, rstr2_ph, ofs) || (ofs += sizeof(u16),
-			memcmp((u8*)rstr1_ph + ofs, (u8*)rstr2_ph + ofs,
-			le32_to_cpu(rstr1_ph->system_page_size) - ofs))) {
-		ntfs_error(vol->sb, "The two restart pages in $LogFile do not "
-				"match.");
-		goto err_out;
-	}
-	ntfs_free(rstr1_ph);
-	ntfs_free(rstr2_ph);
 	/* All consistency checks passed. */
+	if (rp)
+		*rp = rstr1_ph;
+	else
+		ntfs_free(rstr1_ph);
 	ntfs_debug("Done.");
 	return TRUE;
 err_out:
-	if (page)
-		ntfs_unmap_page(page);
 	if (rstr1_ph)
 		ntfs_free(rstr1_ph);
-	if (rstr2_ph)
-		ntfs_free(rstr2_ph);
 	return FALSE;
 }
 
 /**
  * ntfs_is_logfile_clean - check in the journal if the volume is clean
  * @log_vi:	struct inode of loaded journal $LogFile to check
+ * @rp:		copy of the current restart page
  *
  * Analyze the $LogFile journal and return TRUE if it indicates the volume was
  * shutdown cleanly and FALSE if not.
@@ -619,11 +675,9 @@ err_out:
  * is empty this function requires that NVolLogFileEmpty() is true otherwise an
  * empty volume will be reported as dirty.
  */
-BOOL ntfs_is_logfile_clean(struct inode *log_vi)
+BOOL ntfs_is_logfile_clean(struct inode *log_vi, const RESTART_PAGE_HEADER *rp)
 {
 	ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
-	struct page *page;
-	RESTART_PAGE_HEADER *rp;
 	RESTART_AREA *ra;
 
 	ntfs_debug("Entering.");
@@ -632,24 +686,15 @@ BOOL ntfs_is_logfile_clean(struct inode *log_vi)
 		ntfs_debug("Done.  ($LogFile is empty.)");
 		return TRUE;
 	}
-	/*
-	 * Read the first restart page.  It will be possibly incomplete and
-	 * will not be multi sector transfer deprotected but we only need the
-	 * first NTFS_BLOCK_SIZE bytes so it does not matter.
-	 */
-	page = ntfs_map_page(log_vi->i_mapping, 0);
-	if (IS_ERR(page)) {
-		ntfs_error(vol->sb, "Error mapping $LogFile page (index 0).");
+	BUG_ON(!rp);
+	if (!ntfs_is_rstr_record(rp->magic) &&
+			!ntfs_is_chkd_record(rp->magic)) {
+		ntfs_error(vol->sb, "Restart page buffer is invalid.  This is "
+				"probably a bug in that the $LogFile should "
+				"have been consistency checked before calling "
+				"this function.");
 		return FALSE;
 	}
-	rp = (RESTART_PAGE_HEADER*)page_address(page);
-	if (!ntfs_is_rstr_record(rp->magic)) {
-		ntfs_error(vol->sb, "No restart page found at offset zero in "
-				"$LogFile.  This is probably a bug in that "
-				"the $LogFile should have been consistency "
-				"checked before calling this function.");
-		goto err_out;
-	}
 	ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
 	/*
 	 * If the $LogFile has active clients, i.e. it is open, and we do not
@@ -659,15 +704,11 @@ BOOL ntfs_is_logfile_clean(struct inode *log_vi)
 	if (ra->client_in_use_list != LOGFILE_NO_CLIENT &&
 			!(ra->flags & RESTART_VOLUME_IS_CLEAN)) {
 		ntfs_debug("Done.  $LogFile indicates a dirty shutdown.");
-		goto err_out;
+		return FALSE;
 	}
-	ntfs_unmap_page(page);
 	/* $LogFile indicates a clean shutdown. */
 	ntfs_debug("Done.  $LogFile indicates a clean shutdown.");
 	return TRUE;
-err_out:
-	ntfs_unmap_page(page);
-	return FALSE;
 }
 
 /**
diff --git a/fs/ntfs/logfile.h b/fs/ntfs/logfile.h
index 4ee4378de061..a51f3dd0e9eb 100644
--- a/fs/ntfs/logfile.h
+++ b/fs/ntfs/logfile.h
@@ -2,7 +2,7 @@
  * logfile.h - Defines for NTFS kernel journal ($LogFile) handling.  Part of
  *	       the Linux-NTFS project.
  *
- * Copyright (c) 2000-2004 Anton Altaparmakov
+ * Copyright (c) 2000-2005 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -113,7 +113,7 @@ typedef struct {
  */
 enum {
 	RESTART_VOLUME_IS_CLEAN	= const_cpu_to_le16(0x0002),
-	RESTART_SPACE_FILLER	= 0xffff, /* gcc: Force enum bit width to 16. */
+	RESTART_SPACE_FILLER	= const_cpu_to_le16(0xffff), /* gcc: Force enum bit width to 16. */
 } __attribute__ ((__packed__));
 
 typedef le16 RESTART_AREA_FLAGS;
@@ -296,9 +296,11 @@ typedef struct {
 /* sizeof() = 160 (0xa0) bytes */
 } __attribute__ ((__packed__)) LOG_CLIENT_RECORD;
 
-extern BOOL ntfs_check_logfile(struct inode *log_vi);
+extern BOOL ntfs_check_logfile(struct inode *log_vi,
+		RESTART_PAGE_HEADER **rp);
 
-extern BOOL ntfs_is_logfile_clean(struct inode *log_vi);
+extern BOOL ntfs_is_logfile_clean(struct inode *log_vi,
+		const RESTART_PAGE_HEADER *rp);
 
 extern BOOL ntfs_empty_logfile(struct inode *log_vi);
 
diff --git a/fs/ntfs/malloc.h b/fs/ntfs/malloc.h
index fac5944df6d8..e38e402e4103 100644
--- a/fs/ntfs/malloc.h
+++ b/fs/ntfs/malloc.h
@@ -1,7 +1,7 @@
 /*
  * malloc.h - NTFS kernel memory handling. Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2004 Anton Altaparmakov
+ * Copyright (c) 2001-2005 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -27,27 +27,62 @@
 #include <linux/highmem.h>
 
 /**
- * ntfs_malloc_nofs - allocate memory in multiples of pages
- * @size	number of bytes to allocate
+ * __ntfs_malloc - allocate memory in multiples of pages
+ * @size:	number of bytes to allocate
+ * @gfp_mask:	extra flags for the allocator
+ *
+ * Internal function.  You probably want ntfs_malloc_nofs()...
  *
  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
  * returns a pointer to the allocated memory.
  *
  * If there was insufficient memory to complete the request, return NULL.
+ * Depending on @gfp_mask the allocation may be guaranteed to succeed.
  */
-static inline void *ntfs_malloc_nofs(unsigned long size)
+static inline void *__ntfs_malloc(unsigned long size, gfp_t gfp_mask)
 {
 	if (likely(size <= PAGE_SIZE)) {
 		BUG_ON(!size);
 		/* kmalloc() has per-CPU caches so is faster for now. */
-		return kmalloc(PAGE_SIZE, GFP_NOFS);
-		/* return (void *)__get_free_page(GFP_NOFS | __GFP_HIGHMEM); */
+		return kmalloc(PAGE_SIZE, gfp_mask & ~__GFP_HIGHMEM);
+		/* return (void *)__get_free_page(gfp_mask); */
 	}
 	if (likely(size >> PAGE_SHIFT < num_physpages))
-		return __vmalloc(size, GFP_NOFS | __GFP_HIGHMEM, PAGE_KERNEL);
+		return __vmalloc(size, gfp_mask, PAGE_KERNEL);
 	return NULL;
 }
 
+/**
+ * ntfs_malloc_nofs - allocate memory in multiples of pages
+ * @size:	number of bytes to allocate
+ *
+ * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
+ * returns a pointer to the allocated memory.
+ *
+ * If there was insufficient memory to complete the request, return NULL.
+ */
+static inline void *ntfs_malloc_nofs(unsigned long size)
+{
+	return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM);
+}
+
+/**
+ * ntfs_malloc_nofs_nofail - allocate memory in multiples of pages
+ * @size:	number of bytes to allocate
+ *
+ * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
+ * returns a pointer to the allocated memory.
+ *
+ * This function guarantees that the allocation will succeed.  It will sleep
+ * for as long as it takes to complete the allocation.
+ *
+ * If there was insufficient memory to complete the request, return NULL.
+ */
+static inline void *ntfs_malloc_nofs_nofail(unsigned long size)
+{
+	return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM | __GFP_NOFAIL);
+}
+
 static inline void ntfs_free(void *addr)
 {
 	if (likely(((unsigned long)addr < VMALLOC_START) ||
diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
index ac9ff39aa834..0c65cbb8c5cf 100644
--- a/fs/ntfs/mft.c
+++ b/fs/ntfs/mft.c
@@ -49,7 +49,8 @@ static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni)
 	ntfs_volume *vol = ni->vol;
 	struct inode *mft_vi = vol->mft_ino;
 	struct page *page;
-	unsigned long index, ofs, end_index;
+	unsigned long index, end_index;
+	unsigned ofs;
 
 	BUG_ON(ni->page);
 	/*
@@ -58,7 +59,8 @@ static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni)
 	 * overflowing the unsigned long, but I don't think we would ever get
 	 * here if the volume was that big...
 	 */
-	index = ni->mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT;
+	index = (u64)ni->mft_no << vol->mft_record_size_bits >>
+			PAGE_CACHE_SHIFT;
 	ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
 
 	i_size = i_size_read(mft_vi);
@@ -511,7 +513,6 @@ int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no,
 		} while (bh);
 		tail->b_this_page = head;
 		attach_page_buffers(page, head);
-		BUG_ON(!page_has_buffers(page));
 	}
 	bh = head = page_buffers(page);
 	BUG_ON(!bh);
@@ -533,6 +534,7 @@ int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no,
 			LCN lcn;
 			unsigned int vcn_ofs;
 
+			bh->b_bdev = vol->sb->s_bdev;
 			/* Obtain the vcn and offset of the current block. */
 			vcn = ((VCN)mft_no << vol->mft_record_size_bits) +
 					(block_start - m_start);
@@ -691,7 +693,6 @@ int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync)
 	 */
 	if (!NInoTestClearDirty(ni))
 		goto done;
-	BUG_ON(!page_has_buffers(page));
 	bh = head = page_buffers(page);
 	BUG_ON(!bh);
 	rl = NULL;
@@ -725,6 +726,7 @@ int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync)
 			LCN lcn;
 			unsigned int vcn_ofs;
 
+			bh->b_bdev = vol->sb->s_bdev;
 			/* Obtain the vcn and offset of the current block. */
 			vcn = ((VCN)ni->mft_no << vol->mft_record_size_bits) +
 					(block_start - m_start);
@@ -1307,7 +1309,7 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
 	ll = mftbmp_ni->allocated_size;
 	read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
 	rl = ntfs_attr_find_vcn_nolock(mftbmp_ni,
-			(ll - 1) >> vol->cluster_size_bits, TRUE);
+			(ll - 1) >> vol->cluster_size_bits, NULL);
 	if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {
 		up_write(&mftbmp_ni->runlist.lock);
 		ntfs_error(vol->sb, "Failed to determine last allocated "
@@ -1353,7 +1355,8 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
 		up_write(&vol->lcnbmp_lock);
 		ntfs_unmap_page(page);
 		/* Allocate a cluster from the DATA_ZONE. */
-		rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE);
+		rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE,
+				TRUE);
 		if (IS_ERR(rl2)) {
 			up_write(&mftbmp_ni->runlist.lock);
 			ntfs_error(vol->sb, "Failed to allocate a cluster for "
@@ -1737,7 +1740,7 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
 	ll = mft_ni->allocated_size;
 	read_unlock_irqrestore(&mft_ni->size_lock, flags);
 	rl = ntfs_attr_find_vcn_nolock(mft_ni,
-			(ll - 1) >> vol->cluster_size_bits, TRUE);
+			(ll - 1) >> vol->cluster_size_bits, NULL);
 	if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {
 		up_write(&mft_ni->runlist.lock);
 		ntfs_error(vol->sb, "Failed to determine last allocated "
@@ -1778,7 +1781,8 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
 			nr > min_nr ? "default" : "minimal", (long long)nr);
 	old_last_vcn = rl[1].vcn;
 	do {
-		rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE);
+		rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE,
+				TRUE);
 		if (likely(!IS_ERR(rl2)))
 			break;
 		if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) {
@@ -1950,20 +1954,21 @@ restore_undo_alloc:
 		NVolSetErrors(vol);
 		return ret;
 	}
-	a = ctx->attr;
-	a->data.non_resident.highest_vcn = cpu_to_sle64(old_last_vcn - 1);
+	ctx->attr->data.non_resident.highest_vcn =
+			cpu_to_sle64(old_last_vcn - 1);
 undo_alloc:
-	if (ntfs_cluster_free(vol->mft_ino, old_last_vcn, -1) < 0) {
+	if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) {
 		ntfs_error(vol->sb, "Failed to free clusters from mft data "
 				"attribute.%s", es);
 		NVolSetErrors(vol);
 	}
+	a = ctx->attr;
 	if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) {
 		ntfs_error(vol->sb, "Failed to truncate mft data attribute "
 				"runlist.%s", es);
 		NVolSetErrors(vol);
 	}
-	if (mp_rebuilt) {
+	if (mp_rebuilt && !IS_ERR(ctx->mrec)) {
 		if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
 				a->data.non_resident.mapping_pairs_offset),
 				old_alen - le16_to_cpu(
@@ -1980,6 +1985,10 @@ undo_alloc:
 		}
 		flush_dcache_mft_record_page(ctx->ntfs_ino);
 		mark_mft_record_dirty(ctx->ntfs_ino);
+	} else if (IS_ERR(ctx->mrec)) {
+		ntfs_error(vol->sb, "Failed to restore attribute search "
+				"context.%s", es);
+		NVolSetErrors(vol);
 	}
 	if (ctx)
 		ntfs_attr_put_search_ctx(ctx);
diff --git a/fs/ntfs/runlist.c b/fs/ntfs/runlist.c
index 758855b0414e..061b5ff6b73c 100644
--- a/fs/ntfs/runlist.c
+++ b/fs/ntfs/runlist.c
@@ -2,7 +2,7 @@
  * runlist.c - NTFS runlist handling code.  Part of the Linux-NTFS project.
  *
  * Copyright (c) 2001-2005 Anton Altaparmakov
- * Copyright (c) 2002 Richard Russon
+ * Copyright (c) 2002-2005 Richard Russon
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -35,7 +35,7 @@ static inline void ntfs_rl_mm(runlist_element *base, int dst, int src,
 		int size)
 {
 	if (likely((dst != src) && (size > 0)))
-		memmove(base + dst, base + src, size * sizeof (*base));
+		memmove(base + dst, base + src, size * sizeof(*base));
 }
 
 /**
@@ -95,6 +95,51 @@ static inline runlist_element *ntfs_rl_realloc(runlist_element *rl,
 }
 
 /**
+ * ntfs_rl_realloc_nofail - Reallocate memory for runlists
+ * @rl:		original runlist
+ * @old_size:	number of runlist elements in the original runlist @rl
+ * @new_size:	number of runlist elements we need space for
+ *
+ * As the runlists grow, more memory will be required.  To prevent the
+ * kernel having to allocate and reallocate large numbers of small bits of
+ * memory, this function returns an entire page of memory.
+ *
+ * This function guarantees that the allocation will succeed.  It will sleep
+ * for as long as it takes to complete the allocation.
+ *
+ * It is up to the caller to serialize access to the runlist @rl.
+ *
+ * N.B.  If the new allocation doesn't require a different number of pages in
+ *       memory, the function will return the original pointer.
+ *
+ * On success, return a pointer to the newly allocated, or recycled, memory.
+ * On error, return -errno. The following error codes are defined:
+ *	-ENOMEM	- Not enough memory to allocate runlist array.
+ *	-EINVAL	- Invalid parameters were passed in.
+ */
+static inline runlist_element *ntfs_rl_realloc_nofail(runlist_element *rl,
+		int old_size, int new_size)
+{
+	runlist_element *new_rl;
+
+	old_size = PAGE_ALIGN(old_size * sizeof(*rl));
+	new_size = PAGE_ALIGN(new_size * sizeof(*rl));
+	if (old_size == new_size)
+		return rl;
+
+	new_rl = ntfs_malloc_nofs_nofail(new_size);
+	BUG_ON(!new_rl);
+
+	if (likely(rl != NULL)) {
+		if (unlikely(old_size > new_size))
+			old_size = new_size;
+		memcpy(new_rl, rl, old_size);
+		ntfs_free(rl);
+	}
+	return new_rl;
+}
+
+/**
  * ntfs_are_rl_mergeable - test if two runlists can be joined together
  * @dst:	original runlist
  * @src:	new runlist to test for mergeability with @dst
@@ -113,17 +158,21 @@ static inline BOOL ntfs_are_rl_mergeable(runlist_element *dst,
 	BUG_ON(!dst);
 	BUG_ON(!src);
 
-	if ((dst->lcn < 0) || (src->lcn < 0)) {   /* Are we merging holes? */
-		if (dst->lcn == LCN_HOLE && src->lcn == LCN_HOLE)
-			return TRUE;
-		return FALSE;
-	}
-	if ((dst->lcn + dst->length) != src->lcn) /* Are the runs contiguous? */
-		return FALSE;
-	if ((dst->vcn + dst->length) != src->vcn) /* Are the runs misaligned? */
+	/* We can merge unmapped regions even if they are misaligned. */
+	if ((dst->lcn == LCN_RL_NOT_MAPPED) && (src->lcn == LCN_RL_NOT_MAPPED))
+		return TRUE;
+	/* If the runs are misaligned, we cannot merge them. */
+	if ((dst->vcn + dst->length) != src->vcn)
 		return FALSE;
-
-	return TRUE;
+	/* If both runs are non-sparse and contiguous, we can merge them. */
+	if ((dst->lcn >= 0) && (src->lcn >= 0) &&
+			((dst->lcn + dst->length) == src->lcn))
+		return TRUE;
+	/* If we are merging two holes, we can merge them. */
+	if ((dst->lcn == LCN_HOLE) && (src->lcn == LCN_HOLE))
+		return TRUE;
+	/* Cannot merge. */
+	return FALSE;
 }
 
 /**
@@ -169,14 +218,15 @@ static inline void __ntfs_rl_merge(runlist_element *dst, runlist_element *src)
 static inline runlist_element *ntfs_rl_append(runlist_element *dst,
 		int dsize, runlist_element *src, int ssize, int loc)
 {
-	BOOL right;
-	int magic;
+	BOOL right = FALSE;	/* Right end of @src needs merging. */
+	int marker;		/* End of the inserted runs. */
 
 	BUG_ON(!dst);
 	BUG_ON(!src);
 
 	/* First, check if the right hand end needs merging. */
-	right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
+	if ((loc + 1) < dsize)
+		right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
 
 	/* Space required: @dst size + @src size, less one if we merged. */
 	dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - right);
@@ -191,18 +241,19 @@ static inline runlist_element *ntfs_rl_append(runlist_element *dst,
 	if (right)
 		__ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
 
-	magic = loc + ssize;
+	/* First run after the @src runs that have been inserted. */
+	marker = loc + ssize + 1;
 
 	/* Move the tail of @dst out of the way, then copy in @src. */
-	ntfs_rl_mm(dst, magic + 1, loc + 1 + right, dsize - loc - 1 - right);
+	ntfs_rl_mm(dst, marker, loc + 1 + right, dsize - (loc + 1 + right));
 	ntfs_rl_mc(dst, loc + 1, src, 0, ssize);
 
 	/* Adjust the size of the preceding hole. */
 	dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn;
 
 	/* We may have changed the length of the file, so fix the end marker */
-	if (dst[magic + 1].lcn == LCN_ENOENT)
-		dst[magic + 1].vcn = dst[magic].vcn + dst[magic].length;
+	if (dst[marker].lcn == LCN_ENOENT)
+		dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length;
 
 	return dst;
 }
@@ -234,18 +285,17 @@ static inline runlist_element *ntfs_rl_append(runlist_element *dst,
 static inline runlist_element *ntfs_rl_insert(runlist_element *dst,
 		int dsize, runlist_element *src, int ssize, int loc)
 {
-	BOOL left = FALSE;
-	BOOL disc = FALSE;	/* Discontinuity */
-	BOOL hole = FALSE;	/* Following a hole */
-	int magic;
+	BOOL left = FALSE;	/* Left end of @src needs merging. */
+	BOOL disc = FALSE;	/* Discontinuity between @dst and @src. */
+	int marker;		/* End of the inserted runs. */
 
 	BUG_ON(!dst);
 	BUG_ON(!src);
 
-	/* disc => Discontinuity between the end of @dst and the start of @src.
-	 *	   This means we might need to insert a hole.
-	 * hole => @dst ends with a hole or an unmapped region which we can
-	 *	   extend to match the discontinuity. */
+	/*
+	 * disc => Discontinuity between the end of @dst and the start of @src.
+	 *	   This means we might need to insert a "not mapped" run.
+	 */
 	if (loc == 0)
 		disc = (src[0].vcn > 0);
 	else {
@@ -258,58 +308,49 @@ static inline runlist_element *ntfs_rl_insert(runlist_element *dst,
 			merged_length += src->length;
 
 		disc = (src[0].vcn > dst[loc - 1].vcn + merged_length);
-		if (disc)
-			hole = (dst[loc - 1].lcn == LCN_HOLE);
 	}
-
-	/* Space required: @dst size + @src size, less one if we merged, plus
-	 * one if there was a discontinuity, less one for a trailing hole. */
-	dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc - hole);
+	/*
+	 * Space required: @dst size + @src size, less one if we merged, plus
+	 * one if there was a discontinuity.
+	 */
+	dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc);
 	if (IS_ERR(dst))
 		return dst;
 	/*
 	 * We are guaranteed to succeed from here so can start modifying the
 	 * original runlist.
 	 */
-
 	if (left)
 		__ntfs_rl_merge(dst + loc - 1, src);
-
-	magic = loc + ssize - left + disc - hole;
+	/*
+	 * First run after the @src runs that have been inserted.
+	 * Nominally,  @marker equals @loc + @ssize, i.e. location + number of
+	 * runs in @src.  However, if @left, then the first run in @src has
+	 * been merged with one in @dst.  And if @disc, then @dst and @src do
+	 * not meet and we need an extra run to fill the gap.
+	 */
+	marker = loc + ssize - left + disc;
 
 	/* Move the tail of @dst out of the way, then copy in @src. */
-	ntfs_rl_mm(dst, magic, loc, dsize - loc);
-	ntfs_rl_mc(dst, loc + disc - hole, src, left, ssize - left);
+	ntfs_rl_mm(dst, marker, loc, dsize - loc);
+	ntfs_rl_mc(dst, loc + disc, src, left, ssize - left);
 
-	/* Adjust the VCN of the last run ... */
-	if (dst[magic].lcn <= LCN_HOLE)
-		dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length;
+	/* Adjust the VCN of the first run after the insertion... */
+	dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length;
 	/* ... and the length. */
-	if (dst[magic].lcn == LCN_HOLE || dst[magic].lcn == LCN_RL_NOT_MAPPED)
-		dst[magic].length = dst[magic + 1].vcn - dst[magic].vcn;
+	if (dst[marker].lcn == LCN_HOLE || dst[marker].lcn == LCN_RL_NOT_MAPPED)
+		dst[marker].length = dst[marker + 1].vcn - dst[marker].vcn;
 
-	/* Writing beyond the end of the file and there's a discontinuity. */
+	/* Writing beyond the end of the file and there is a discontinuity. */
 	if (disc) {
-		if (hole)
-			dst[loc - 1].length = dst[loc].vcn - dst[loc - 1].vcn;
-		else {
-			if (loc > 0) {
-				dst[loc].vcn = dst[loc - 1].vcn +
-						dst[loc - 1].length;
-				dst[loc].length = dst[loc + 1].vcn -
-						dst[loc].vcn;
-			} else {
-				dst[loc].vcn = 0;
-				dst[loc].length = dst[loc + 1].vcn;
-			}
-			dst[loc].lcn = LCN_RL_NOT_MAPPED;
+		if (loc > 0) {
+			dst[loc].vcn = dst[loc - 1].vcn + dst[loc - 1].length;
+			dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn;
+		} else {
+			dst[loc].vcn = 0;
+			dst[loc].length = dst[loc + 1].vcn;
 		}
-
-		magic += hole;
-
-		if (dst[magic].lcn == LCN_ENOENT)
-			dst[magic].vcn = dst[magic - 1].vcn +
-					dst[magic - 1].length;
+		dst[loc].lcn = LCN_RL_NOT_MAPPED;
 	}
 	return dst;
 }
@@ -340,20 +381,23 @@ static inline runlist_element *ntfs_rl_insert(runlist_element *dst,
 static inline runlist_element *ntfs_rl_replace(runlist_element *dst,
 		int dsize, runlist_element *src, int ssize, int loc)
 {
-	BOOL left = FALSE;
-	BOOL right;
-	int magic;
+	BOOL left = FALSE;	/* Left end of @src needs merging. */
+	BOOL right = FALSE;	/* Right end of @src needs merging. */
+	int tail;		/* Start of tail of @dst. */
+	int marker;		/* End of the inserted runs. */
 
 	BUG_ON(!dst);
 	BUG_ON(!src);
 
-	/* First, merge the left and right ends, if necessary. */
-	right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
+	/* First, see if the left and right ends need merging. */
+	if ((loc + 1) < dsize)
+		right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
 	if (loc > 0)
 		left = ntfs_are_rl_mergeable(dst + loc - 1, src);
-
-	/* Allocate some space. We'll need less if the left, right, or both
-	 * ends were merged. */
+	/*
+	 * Allocate some space.  We will need less if the left, right, or both
+	 * ends get merged.
+	 */
 	dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left - right);
 	if (IS_ERR(dst))
 		return dst;
@@ -361,21 +405,37 @@ static inline runlist_element *ntfs_rl_replace(runlist_element *dst,
 	 * We are guaranteed to succeed from here so can start modifying the
 	 * original runlists.
 	 */
+
+	/* First, merge the left and right ends, if necessary. */
 	if (right)
 		__ntfs_rl_merge(src + ssize - 1, dst + loc + 1);
 	if (left)
 		__ntfs_rl_merge(dst + loc - 1, src);
-
-	/* FIXME: What does this mean? (AIA) */
-	magic = loc + ssize - left;
+	/*
+	 * Offset of the tail of @dst.  This needs to be moved out of the way
+	 * to make space for the runs to be copied from @src, i.e. the first
+	 * run of the tail of @dst.
+	 * Nominally, @tail equals @loc + 1, i.e. location, skipping the
+	 * replaced run.  However, if @right, then one of @dst's runs is
+	 * already merged into @src.
+	 */
+	tail = loc + right + 1;
+	/*
+	 * First run after the @src runs that have been inserted, i.e. where
+	 * the tail of @dst needs to be moved to.
+	 * Nominally, @marker equals @loc + @ssize, i.e. location + number of
+	 * runs in @src.  However, if @left, then the first run in @src has
+	 * been merged with one in @dst.
+	 */
+	marker = loc + ssize - left;
 
 	/* Move the tail of @dst out of the way, then copy in @src. */
-	ntfs_rl_mm(dst, magic, loc + right + 1, dsize - loc - right - 1);
+	ntfs_rl_mm(dst, marker, tail, dsize - tail);
 	ntfs_rl_mc(dst, loc, src, left, ssize - left);
 
-	/* We may have changed the length of the file, so fix the end marker */
-	if (dst[magic].lcn == LCN_ENOENT)
-		dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length;
+	/* We may have changed the length of the file, so fix the end marker. */
+	if (dsize - tail > 0 && dst[marker].lcn == LCN_ENOENT)
+		dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length;
 	return dst;
 }
 
@@ -497,6 +557,7 @@ runlist_element *ntfs_runlists_merge(runlist_element *drl,
 			/* Scan to the end of the source runlist. */
 			for (dend = 0; likely(drl[dend].length); dend++)
 				;
+			dend++;
 			drl = ntfs_rl_realloc(drl, dend, dend + 1);
 			if (IS_ERR(drl))
 				return drl;
@@ -566,8 +627,8 @@ runlist_element *ntfs_runlists_merge(runlist_element *drl,
 		 ((drl[dins].vcn + drl[dins].length) <=      /* End of hole   */
 		  (srl[send - 1].vcn + srl[send - 1].length)));
 
-	/* Or we'll lose an end marker */
-	if (start && finish && (drl[dins].length == 0))
+	/* Or we will lose an end marker. */
+	if (finish && !drl[dins].length)
 		ss++;
 	if (marker && (drl[dins].vcn + drl[dins].length > srl[send - 1].vcn))
 		finish = FALSE;
@@ -621,11 +682,8 @@ runlist_element *ntfs_runlists_merge(runlist_element *drl,
 			if (drl[ds].lcn != LCN_RL_NOT_MAPPED) {
 				/* Add an unmapped runlist element. */
 				if (!slots) {
-					/* FIXME/TODO: We need to have the
-					 * extra memory already! (AIA) */
-					drl = ntfs_rl_realloc(drl, ds, ds + 2);
-					if (!drl)
-						goto critical_error;
+					drl = ntfs_rl_realloc_nofail(drl, ds,
+							ds + 2);
 					slots = 2;
 				}
 				ds++;
@@ -640,13 +698,8 @@ runlist_element *ntfs_runlists_merge(runlist_element *drl,
 			drl[ds].length = marker_vcn - drl[ds].vcn;
 			/* Finally add the ENOENT terminator. */
 			ds++;
-			if (!slots) {
-				/* FIXME/TODO: We need to have the extra
-				 * memory already! (AIA) */
-				drl = ntfs_rl_realloc(drl, ds, ds + 1);
-				if (!drl)
-					goto critical_error;
-			}
+			if (!slots)
+				drl = ntfs_rl_realloc_nofail(drl, ds, ds + 1);
 			drl[ds].vcn = marker_vcn;
 			drl[ds].lcn = LCN_ENOENT;
 			drl[ds].length = (s64)0;
@@ -659,11 +712,6 @@ finished:
 	ntfs_debug("Merged runlist:");
 	ntfs_debug_dump_runlist(drl);
 	return drl;
-
-critical_error:
-	/* Critical error! We cannot afford to fail here. */
-	ntfs_error(NULL, "Critical error! Not enough memory.");
-	panic("NTFS: Cannot continue.");
 }
 
 /**
@@ -727,6 +775,9 @@ runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol,
 		ntfs_error(vol->sb, "Corrupt attribute.");
 		return ERR_PTR(-EIO);
 	}
+	/* If the mapping pairs array is valid but empty, nothing to do. */
+	if (!vcn && !*buf)
+		return old_rl;
 	/* Current position in runlist array. */
 	rlpos = 0;
 	/* Allocate first page and set current runlist size to one page. */
@@ -1419,6 +1470,7 @@ err_out:
 
 /**
  * ntfs_rl_truncate_nolock - truncate a runlist starting at a specified vcn
+ * @vol:	ntfs volume (needed for error output)
  * @runlist:	runlist to truncate
  * @new_length:	the new length of the runlist in VCNs
  *
@@ -1426,12 +1478,16 @@ err_out:
  * holding the runlist elements to a length of @new_length VCNs.
  *
  * If @new_length lies within the runlist, the runlist elements with VCNs of
- * @new_length and above are discarded.
+ * @new_length and above are discarded.  As a special case if @new_length is
+ * zero, the runlist is discarded and set to NULL.
  *
  * If @new_length lies beyond the runlist, a sparse runlist element is added to
  * the end of the runlist @runlist or if the last runlist element is a sparse
  * one already, this is extended.
  *
+ * Note, no checking is done for unmapped runlist elements.  It is assumed that
+ * the caller has mapped any elements that need to be mapped already.
+ *
  * Return 0 on success and -errno on error.
  *
  * Locking: The caller must hold @runlist->lock for writing.
@@ -1446,6 +1502,13 @@ int ntfs_rl_truncate_nolock(const ntfs_volume *vol, runlist *const runlist,
 	BUG_ON(!runlist);
 	BUG_ON(new_length < 0);
 	rl = runlist->rl;
+	if (!new_length) {
+		ntfs_debug("Freeing runlist.");
+		runlist->rl = NULL;
+		if (rl)
+			ntfs_free(rl);
+		return 0;
+	}
 	if (unlikely(!rl)) {
 		/*
 		 * Create a runlist consisting of a sparse runlist element of
@@ -1553,4 +1616,288 @@ int ntfs_rl_truncate_nolock(const ntfs_volume *vol, runlist *const runlist,
 	return 0;
 }
 
+/**
+ * ntfs_rl_punch_nolock - punch a hole into a runlist
+ * @vol:	ntfs volume (needed for error output)
+ * @runlist:	runlist to punch a hole into
+ * @start:	starting VCN of the hole to be created
+ * @length:	size of the hole to be created in units of clusters
+ *
+ * Punch a hole into the runlist @runlist starting at VCN @start and of size
+ * @length clusters.
+ *
+ * Return 0 on success and -errno on error, in which case @runlist has not been
+ * modified.
+ *
+ * If @start and/or @start + @length are outside the runlist return error code
+ * -ENOENT.
+ *
+ * If the runlist contains unmapped or error elements between @start and @start
+ * + @length return error code -EINVAL.
+ *
+ * Locking: The caller must hold @runlist->lock for writing.
+ */
+int ntfs_rl_punch_nolock(const ntfs_volume *vol, runlist *const runlist,
+		const VCN start, const s64 length)
+{
+	const VCN end = start + length;
+	s64 delta;
+	runlist_element *rl, *rl_end, *rl_real_end, *trl;
+	int old_size;
+	BOOL lcn_fixup = FALSE;
+
+	ntfs_debug("Entering for start 0x%llx, length 0x%llx.",
+			(long long)start, (long long)length);
+	BUG_ON(!runlist);
+	BUG_ON(start < 0);
+	BUG_ON(length < 0);
+	BUG_ON(end < 0);
+	rl = runlist->rl;
+	if (unlikely(!rl)) {
+		if (likely(!start && !length))
+			return 0;
+		return -ENOENT;
+	}
+	/* Find @start in the runlist. */
+	while (likely(rl->length && start >= rl[1].vcn))
+		rl++;
+	rl_end = rl;
+	/* Find @end in the runlist. */
+	while (likely(rl_end->length && end >= rl_end[1].vcn)) {
+		/* Verify there are no unmapped or error elements. */
+		if (unlikely(rl_end->lcn < LCN_HOLE))
+			return -EINVAL;
+		rl_end++;
+	}
+	/* Check the last element. */
+	if (unlikely(rl_end->length && rl_end->lcn < LCN_HOLE))
+		return -EINVAL;
+	/* This covers @start being out of bounds, too. */
+	if (!rl_end->length && end > rl_end->vcn)
+		return -ENOENT;
+	if (!length)
+		return 0;
+	if (!rl->length)
+		return -ENOENT;
+	rl_real_end = rl_end;
+	/* Determine the runlist size. */
+	while (likely(rl_real_end->length))
+		rl_real_end++;
+	old_size = rl_real_end - runlist->rl + 1;
+	/* If @start is in a hole simply extend the hole. */
+	if (rl->lcn == LCN_HOLE) {
+		/*
+		 * If both @start and @end are in the same sparse run, we are
+		 * done.
+		 */
+		if (end <= rl[1].vcn) {
+			ntfs_debug("Done (requested hole is already sparse).");
+			return 0;
+		}
+extend_hole:
+		/* Extend the hole. */
+		rl->length = end - rl->vcn;
+		/* If @end is in a hole, merge it with the current one. */
+		if (rl_end->lcn == LCN_HOLE) {
+			rl_end++;
+			rl->length = rl_end->vcn - rl->vcn;
+		}
+		/* We have done the hole.  Now deal with the remaining tail. */
+		rl++;
+		/* Cut out all runlist elements up to @end. */
+		if (rl < rl_end)
+			memmove(rl, rl_end, (rl_real_end - rl_end + 1) *
+					sizeof(*rl));
+		/* Adjust the beginning of the tail if necessary. */
+		if (end > rl->vcn) {
+			s64 delta = end - rl->vcn;
+			rl->vcn = end;
+			rl->length -= delta;
+			/* Only adjust the lcn if it is real. */
+			if (rl->lcn >= 0)
+				rl->lcn += delta;
+		}
+shrink_allocation:
+		/* Reallocate memory if the allocation changed. */
+		if (rl < rl_end) {
+			rl = ntfs_rl_realloc(runlist->rl, old_size,
+					old_size - (rl_end - rl));
+			if (IS_ERR(rl))
+				ntfs_warning(vol->sb, "Failed to shrink "
+						"runlist buffer.  This just "
+						"wastes a bit of memory "
+						"temporarily so we ignore it "
+						"and return success.");
+			else
+				runlist->rl = rl;
+		}
+		ntfs_debug("Done (extend hole).");
+		return 0;
+	}
+	/*
+	 * If @start is at the beginning of a run things are easier as there is
+	 * no need to split the first run.
+	 */
+	if (start == rl->vcn) {
+		/*
+		 * @start is at the beginning of a run.
+		 *
+		 * If the previous run is sparse, extend its hole.
+		 *
+		 * If @end is not in the same run, switch the run to be sparse
+		 * and extend the newly created hole.
+		 *
+		 * Thus both of these cases reduce the problem to the above
+		 * case of "@start is in a hole".
+		 */
+		if (rl > runlist->rl && (rl - 1)->lcn == LCN_HOLE) {
+			rl--;
+			goto extend_hole;
+		}
+		if (end >= rl[1].vcn) {
+			rl->lcn = LCN_HOLE;
+			goto extend_hole;
+		}
+		/*
+		 * The final case is when @end is in the same run as @start.
+		 * For this need to split the run into two.  One run for the
+		 * sparse region between the beginning of the old run, i.e.
+		 * @start, and @end and one for the remaining non-sparse
+		 * region, i.e. between @end and the end of the old run.
+		 */
+		trl = ntfs_rl_realloc(runlist->rl, old_size, old_size + 1);
+		if (IS_ERR(trl))
+			goto enomem_out;
+		old_size++;
+		if (runlist->rl != trl) {
+			rl = trl + (rl - runlist->rl);
+			rl_end = trl + (rl_end - runlist->rl);
+			rl_real_end = trl + (rl_real_end - runlist->rl);
+			runlist->rl = trl;
+		}
+split_end:
+		/* Shift all the runs up by one. */
+		memmove(rl + 1, rl, (rl_real_end - rl + 1) * sizeof(*rl));
+		/* Finally, setup the two split runs. */
+		rl->lcn = LCN_HOLE;
+		rl->length = length;
+		rl++;
+		rl->vcn += length;
+		/* Only adjust the lcn if it is real. */
+		if (rl->lcn >= 0 || lcn_fixup)
+			rl->lcn += length;
+		rl->length -= length;
+		ntfs_debug("Done (split one).");
+		return 0;
+	}
+	/*
+	 * @start is neither in a hole nor at the beginning of a run.
+	 *
+	 * If @end is in a hole, things are easier as simply truncating the run
+	 * @start is in to end at @start - 1, deleting all runs after that up
+	 * to @end, and finally extending the beginning of the run @end is in
+	 * to be @start is all that is needed.
+	 */
+	if (rl_end->lcn == LCN_HOLE) {
+		/* Truncate the run containing @start. */
+		rl->length = start - rl->vcn;
+		rl++;
+		/* Cut out all runlist elements up to @end. */
+		if (rl < rl_end)
+			memmove(rl, rl_end, (rl_real_end - rl_end + 1) *
+					sizeof(*rl));
+		/* Extend the beginning of the run @end is in to be @start. */
+		rl->vcn = start;
+		rl->length = rl[1].vcn - start;
+		goto shrink_allocation;
+	}
+	/* 
+	 * If @end is not in a hole there are still two cases to distinguish.
+	 * Either @end is or is not in the same run as @start.
+	 *
+	 * The second case is easier as it can be reduced to an already solved
+	 * problem by truncating the run @start is in to end at @start - 1.
+	 * Then, if @end is in the next run need to split the run into a sparse
+	 * run followed by a non-sparse run (already covered above) and if @end
+	 * is not in the next run switching it to be sparse, again reduces the
+	 * problem to the already covered case of "@start is in a hole".
+	 */
+	if (end >= rl[1].vcn) {
+		/*
+		 * If @end is not in the next run, reduce the problem to the
+		 * case of "@start is in a hole".
+		 */
+		if (rl[1].length && end >= rl[2].vcn) {
+			/* Truncate the run containing @start. */
+			rl->length = start - rl->vcn;
+			rl++;
+			rl->vcn = start;
+			rl->lcn = LCN_HOLE;
+			goto extend_hole;
+		}
+		trl = ntfs_rl_realloc(runlist->rl, old_size, old_size + 1);
+		if (IS_ERR(trl))
+			goto enomem_out;
+		old_size++;
+		if (runlist->rl != trl) {
+			rl = trl + (rl - runlist->rl);
+			rl_end = trl + (rl_end - runlist->rl);
+			rl_real_end = trl + (rl_real_end - runlist->rl);
+			runlist->rl = trl;
+		}
+		/* Truncate the run containing @start. */
+		rl->length = start - rl->vcn;
+		rl++;
+		/*
+		 * @end is in the next run, reduce the problem to the case
+		 * where "@start is at the beginning of a run and @end is in
+		 * the same run as @start".
+		 */
+		delta = rl->vcn - start;
+		rl->vcn = start;
+		if (rl->lcn >= 0) {
+			rl->lcn -= delta;
+			/* Need this in case the lcn just became negative. */
+			lcn_fixup = TRUE;
+		}
+		rl->length += delta;
+		goto split_end;
+	}
+	/*
+	 * The first case from above, i.e. @end is in the same run as @start.
+	 * We need to split the run into three.  One run for the non-sparse
+	 * region between the beginning of the old run and @start, one for the
+	 * sparse region between @start and @end, and one for the remaining
+	 * non-sparse region, i.e. between @end and the end of the old run.
+	 */
+	trl = ntfs_rl_realloc(runlist->rl, old_size, old_size + 2);
+	if (IS_ERR(trl))
+		goto enomem_out;
+	old_size += 2;
+	if (runlist->rl != trl) {
+		rl = trl + (rl - runlist->rl);
+		rl_end = trl + (rl_end - runlist->rl);
+		rl_real_end = trl + (rl_real_end - runlist->rl);
+		runlist->rl = trl;
+	}
+	/* Shift all the runs up by two. */
+	memmove(rl + 2, rl, (rl_real_end - rl + 1) * sizeof(*rl));
+	/* Finally, setup the three split runs. */
+	rl->length = start - rl->vcn;
+	rl++;
+	rl->vcn = start;
+	rl->lcn = LCN_HOLE;
+	rl->length = length;
+	rl++;
+	delta = end - rl->vcn;
+	rl->vcn = end;
+	rl->lcn += delta;
+	rl->length -= delta;
+	ntfs_debug("Done (split both).");
+	return 0;
+enomem_out:
+	ntfs_error(vol->sb, "Not enough memory to extend runlist buffer.");
+	return -ENOMEM;
+}
+
 #endif /* NTFS_RW */
diff --git a/fs/ntfs/runlist.h b/fs/ntfs/runlist.h
index aa0ee6540e7c..47728fbb610b 100644
--- a/fs/ntfs/runlist.h
+++ b/fs/ntfs/runlist.h
@@ -94,6 +94,9 @@ extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
 extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol,
 		runlist *const runlist, const s64 new_length);
 
+int ntfs_rl_punch_nolock(const ntfs_volume *vol, runlist *const runlist,
+		const VCN start, const s64 length);
+
 #endif /* NTFS_RW */
 
 #endif /* _LINUX_NTFS_RUNLIST_H */
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 41aa8eb6755b..6c16db9e1a8a 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -126,6 +126,14 @@ static BOOL parse_options(ntfs_volume *vol, char *opt)
 		if (*v)							\
 			goto needs_val;					\
 	}
+#define NTFS_GETOPT_OCTAL(option, variable)				\
+	if (!strcmp(p, option)) {					\
+		if (!v || !*v)						\
+			goto needs_arg;					\
+		variable = simple_strtoul(ov = v, &v, 8);		\
+		if (*v)							\
+			goto needs_val;					\
+	}
 #define NTFS_GETOPT_BOOL(option, variable)				\
 	if (!strcmp(p, option)) {					\
 		BOOL val;						\
@@ -157,9 +165,9 @@ static BOOL parse_options(ntfs_volume *vol, char *opt)
 			*v++ = 0;
 		NTFS_GETOPT("uid", uid)
 		else NTFS_GETOPT("gid", gid)
-		else NTFS_GETOPT("umask", fmask = dmask)
-		else NTFS_GETOPT("fmask", fmask)
-		else NTFS_GETOPT("dmask", dmask)
+		else NTFS_GETOPT_OCTAL("umask", fmask = dmask)
+		else NTFS_GETOPT_OCTAL("fmask", fmask)
+		else NTFS_GETOPT_OCTAL("dmask", dmask)
 		else NTFS_GETOPT("mft_zone_multiplier", mft_zone_multiplier)
 		else NTFS_GETOPT_WITH_DEFAULT("sloppy", sloppy, TRUE)
 		else NTFS_GETOPT_BOOL("show_sys_files", show_sys_files)
@@ -1133,7 +1141,8 @@ mft_unmap_out:
  *
  * Return TRUE on success or FALSE on error.
  */
-static BOOL load_and_check_logfile(ntfs_volume *vol)
+static BOOL load_and_check_logfile(ntfs_volume *vol,
+		RESTART_PAGE_HEADER **rp)
 {
 	struct inode *tmp_ino;
 
@@ -1145,7 +1154,7 @@ static BOOL load_and_check_logfile(ntfs_volume *vol)
 		/* Caller will display error message. */
 		return FALSE;
 	}
-	if (!ntfs_check_logfile(tmp_ino)) {
+	if (!ntfs_check_logfile(tmp_ino, rp)) {
 		iput(tmp_ino);
 		/* ntfs_check_logfile() will have displayed error output. */
 		return FALSE;
@@ -1438,7 +1447,7 @@ not_enabled:
 	if (unlikely(i_size_read(tmp_ino) < sizeof(USN_HEADER))) {
 		ntfs_error(vol->sb, "Found corrupt $UsnJrnl/$DATA/$Max "
 				"attribute (size is 0x%llx but should be at "
-				"least 0x%x bytes).", i_size_read(tmp_ino),
+				"least 0x%zx bytes).", i_size_read(tmp_ino),
 				sizeof(USN_HEADER));
 		return FALSE;
 	}
@@ -1689,6 +1698,7 @@ static BOOL load_system_files(ntfs_volume *vol)
 	VOLUME_INFORMATION *vi;
 	ntfs_attr_search_ctx *ctx;
 #ifdef NTFS_RW
+	RESTART_PAGE_HEADER *rp;
 	int err;
 #endif /* NTFS_RW */
 
@@ -1841,8 +1851,9 @@ get_ctx_vol_failed:
 	 * Get the inode for the logfile, check it and determine if the volume
 	 * was shutdown cleanly.
 	 */
-	if (!load_and_check_logfile(vol) ||
-			!ntfs_is_logfile_clean(vol->logfile_ino)) {
+	rp = NULL;
+	if (!load_and_check_logfile(vol, &rp) ||
+			!ntfs_is_logfile_clean(vol->logfile_ino, rp)) {
 		static const char *es1a = "Failed to load $LogFile";
 		static const char *es1b = "$LogFile is not clean";
 		static const char *es2 = ".  Mount in Windows.";
@@ -1857,6 +1868,10 @@ get_ctx_vol_failed:
 						"continue nor on_errors="
 						"remount-ro was specified%s",
 						es1, es2);
+				if (vol->logfile_ino) {
+					BUG_ON(!rp);
+					ntfs_free(rp);
+				}
 				goto iput_logfile_err_out;
 			}
 			sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
@@ -1867,6 +1882,7 @@ get_ctx_vol_failed:
 		/* This will prevent a read-write remount. */
 		NVolSetErrors(vol);
 	}
+	ntfs_free(rp);
 #endif /* NTFS_RW */
 	/* Get the root directory inode so we can do path lookups. */
 	vol->root_ino = ntfs_iget(sb, FILE_root);
diff --git a/fs/ntfs/unistr.c b/fs/ntfs/unistr.c
index 19c42e231b44..0ea887fc859c 100644
--- a/fs/ntfs/unistr.c
+++ b/fs/ntfs/unistr.c
@@ -1,7 +1,7 @@
 /*
  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2004 Anton Altaparmakov
+ * Copyright (c) 2001-2005 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -372,7 +372,8 @@ retry:			wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
 	return -EINVAL;
 conversion_err:
 	ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
-			"converted to character set %s.", nls->charset);
+			"converted to character set %s.  You might want to "
+			"try to use the mount option nls=utf8.", nls->charset);
 	if (ns != *outs)
 		kfree(ns);
 	if (wc != -ENAMETOOLONG)