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2015-02-16ext4: add DAX functionalityRoss Zwisler1-0/+4
This is a port of the DAX functionality found in the current version of ext2. [matthew.r.wilcox@intel.com: heavily tweaked] [akpm@linux-foundation.org: remap_pages went away] Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-06Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivialLinus Torvalds1-1/+1
Pull trivial tree from Jiri Kosina: "The usual trivial updates all over the tree -- mostly typo fixes and documentation updates" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits) doc: Documentation/cputopology.txt fix typo treewide: Convert retrun typos to return Fix comment typo for init_cma_reserved_pageblock Documentation/trace: Correcting and extending tracepoint documentation mm/hotplug: fix a typo in Documentation/memory-hotplug.txt power: Documentation: Update s2ram link doc: fix a typo in Documentation/00-INDEX Documentation/printk-formats.txt: No casts needed for u64/s64 doc: Fix typo "is is" in Documentations treewide: Fix printks with 0x%# zram: doc fixes Documentation/kmemcheck: update kmemcheck documentation doc: documentation/hwspinlock.txt fix typo PM / Hibernate: add section for resume options doc: filesystems : Fix typo in Documentations/filesystems scsi/megaraid fixed several typos in comments ppc: init_32: Fix error typo "CONFIG_START_KERNEL" treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks page_isolation: Fix a comment typo in test_pages_isolated() doc: fix a typo about irq affinity ...
2013-08-28ext4: allow specifying external journal by pathname mount optionEric Sandeen1-3/+4
It's always been a hassle that if an external journal's device number changes, the filesystem won't mount. And since boot-time enumeration can change, device number changes aren't unusual. The current mechanism to update the journal location is by passing in a mount option w/ a new devnum, but that's a hassle; it's a manual approach, fixing things after the fact. Adding a mount option, "-o journal_path=/dev/$DEVICE" would help, since then we can do i.e. # mount -o journal_path=/dev/disk/by-label/$JOURNAL_LABEL ... and it'll mount even if the devnum has changed, as shown here: # losetup /dev/loop0 journalfile # mke2fs -L mylabel-journal -O journal_dev /dev/loop0 # mkfs.ext4 -L mylabel -J device=/dev/loop0 /dev/sdb1 Change the journal device number: # losetup -d /dev/loop0 # losetup /dev/loop1 journalfile And today it will fail: # mount /dev/sdb1 /mnt/test mount: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so # dmesg | tail -n 1 [17343.240702] EXT4-fs (sdb1): error: couldn't read superblock of external journal But with this new mount option, we can specify the new path: # mount -o journal_path=/dev/loop1 /dev/sdb1 /mnt/test # (which does update the encoded device number, incidentally): # umount /dev/sdb1 # dumpe2fs -h /dev/sdb1 | grep "Journal device" dumpe2fs 1.41.12 (17-May-2010) Journal device: 0x0701 But best of all we can just always mount by journal-path, and it'll always work: # mount -o journal_path=/dev/disk/by-label/mylabel-journal /dev/sdb1 /mnt/test # So the journal_path option can be specified in fstab, and as long as the disk is available somewhere, and findable by label (or by UUID), we can mount. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2013-07-25doc: Fix typo in doucmentationsMasanari Iida1-1/+1
Correct typo (double words) in documentations. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-04-09ext4: introduce reserved spaceLukas Czerner1-0/+11
Currently in ENOSPC condition when writing into unwritten space, or punching a hole, we might need to split the extent and grow extent tree. However since we can not allocate any new metadata blocks we'll have to zero out unwritten part of extent or punched out part of extent, or in the worst case return ENOSPC even though use actually does not allocate any space. Also in delalloc path we do reserve metadata and data blocks for the time we're going to write out, however metadata block reservation is very tricky especially since we expect that logical connectivity implies physical connectivity, however that might not be the case and hence we might end up allocating more metadata blocks than previously reserved. So in future, metadata reservation checks should be removed since we can not assure that we do not under reserve. And this is where reserved space comes into the picture. When mounting the file system we slice off a little bit of the file system space (2% or 4096 clusters, whichever is smaller) which can be then used for the cases mentioned above to prevent costly zeroout, or unexpected ENOSPC. The number of reserved clusters can be set via sysfs, however it can never be bigger than number of free clusters in the file system. Note that this patch fixes the failure of xfstest 274 as expected. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2013-04-08ext4: implementation of a new ioctl called EXT4_IOC_SWAP_BOOTDr. Tilmann Bubeck1-0/+10
Add a new ioctl, EXT4_IOC_SWAP_BOOT which swaps i_blocks and associated attributes (like i_blocks, i_size, i_flags, ...) from the specified inode with inode EXT4_BOOT_LOADER_INO (#5). This is typically used to store a boot loader in a secure part of the filesystem, where it can't be changed by a normal user by accident. The data blocks of the previous boot loader will be associated with the given inode. This usercode program is a simple example of the usage: int main(int argc, char *argv[]) { int fd; int err; if ( argc != 2 ) { printf("usage: ext4-swap-boot-inode FILE-TO-SWAP\n"); exit(1); } fd = open(argv[1], O_WRONLY); if ( fd < 0 ) { perror("open"); exit(1); } err = ioctl(fd, EXT4_IOC_SWAP_BOOT); if ( err < 0 ) { perror("ioctl"); exit(1); } close(fd); exit(0); } [ Modified by Theodore Ts'o to fix a number of bugs in the original code.] Signed-off-by: Dr. Tilmann Bubeck <t.bubeck@reinform.de> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: Remove CONFIG_EXT4_FS_XATTRTao Ma1-6/+3
Ted has sent out a RFC about removing this feature. Eric and Jan confirmed that both RedHat and SUSE enable this feature in all their product. David also said that "As far as I know, it's enabled in all Android kernels that use ext4." So it seems OK for us. And what's more, as inline data depends its implementation on xattr, and to be frank, I don't run any test again inline data enabled while xattr disabled. So I think we should add inline data and remove this config option in the same release. [ The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which isn't much in the grand scheme of things. Since no one seems to be testing this configuration except for some automated compile farms, on balance we are better removing this config option, and so that it is effectively always enabled. -- tytso ] Cc: David Brown <davidb@codeaurora.org> Cc: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-08-17ext4: add max_dir_size_kb mount optionTheodore Ts'o1-0/+10
Very large directories can cause significant performance problems, or perhaps even invoke the OOM killer, if the process is running in a highly constrained memory environment (whether it is VM's with a small amount of memory or in a small memory cgroup). So it is useful, in cloud server/data center environments, to be able to set a filesystem-wide cap on the maximum size of a directory, to ensure that directories never get larger than a sane size. We do this via a new mount option, max_dir_size_kb. If there is an attempt to grow the directory larger than max_dir_size_kb, the system call will return ENOSPC instead. Google-Bug-Id: 6863013 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-28Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4Linus Torvalds1-8/+0
Pull ext4 updates for 3.4 from Ted Ts'o: "Ext4 commits for 3.3 merge window; mostly cleanups and bug fixes The changes to export dirty_writeback_interval are from Artem's s_dirt cleanup patch series. The same is true of the change to remove the s_dirt helper functions which never got used by anyone in-tree. I've run these changes by Al Viro, and am carrying them so that Artem can more easily fix up the rest of the file systems during the next merge window. (Originally we had hopped to remove the use of s_dirt from ext4 during this merge window, but his patches had some bugs, so I ultimately ended dropping them from the ext4 tree.)" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (66 commits) vfs: remove unused superblock helpers mm: export dirty_writeback_interval ext4: remove useless s_dirt assignment ext4: write superblock only once on unmount ext4: do not mark superblock as dirty unnecessarily ext4: correct ext4_punch_hole return codes ext4: remove restrictive checks for EOFBLOCKS_FL ext4: always set then trimmed blocks count into len ext4: fix trimmed block count accunting ext4: fix start and len arguments handling in ext4_trim_fs() ext4: update s_free_{inodes,blocks}_count during online resize ext4: change some printk() calls to use ext4_msg() instead ext4: avoid output message interleaving in ext4_error_<foo>() ext4: remove trailing newlines from ext4_msg() and ext4_error() messages ext4: add no_printk argument validation, fix fallout ext4: remove redundant "EXT4-fs: " from uses of ext4_msg ext4: give more helpful error message in ext4_ext_rm_leaf() ext4: remove unused code from ext4_ext_map_blocks() ext4: rewrite punch hole to use ext4_ext_remove_space() jbd2: cleanup journal tail after transaction commit ...
2012-03-07Documentation: Fix multiple typo in DocumentationMasanari Iida1-2/+2
Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-02-20ext4: remove the resize mount optionEric Sandeen1-5/+0
The resize mount option seems to be of limited value, especially in the age of online resize2fs. Nuke it. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-02-20ext4: remove the journal=update mount optionEric Sandeen1-3/+0
The V2 journal format was introduced around ten years ago, for ext3. It seems highly unlikely that anyone will need this migration option for ext4. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-01-04ext4: add new online resize interfaceYongqiang Yang1-0/+7
This patch adds new online resize interface, whose input argument is a 64-bit integer indicating how many blocks there are in the resized fs. In new resize impelmentation, all work like allocating group tables are done by kernel side, so the new resize interface can support flex_bg feature and prepares ground for suppoting resize with features like bigalloc and exclude bitmap. Besides these, user-space tools just passes in the new number of blocks. We delay initializing the bitmaps and inode tables of added groups if possible and add multi groups (a flex groups) each time, so new resize is very fast like mkfs. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-08ext4: remove deprecated oldallocLukas Czerner1-8/+0
For a long time now orlov is the default block allocator in the ext4. It performs better than the old one and no one seems to claim otherwise so we can safely drop it and make oldalloc and orlov mount option deprecated. This is a part of the effort to reduce number of ext4 options hence the test matrix. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-08ext4: documentation: remove acl and user_xattr mount optionsTheodore Ts'o1-14/+11
Acl and user_xattr mount options are no longer needed since those features are enabled by default if configured in (seee commit ea6633369458992241599c9d9ebadffaeddec164). We can not easily deprecate mount options itself (since it is probably too early), but we can remove it from documentation first. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-03ext4: improve handling of conflicting mount optionsTheodore Ts'o1-3/+5
If the user explicitly specifies conflicting mount options for delalloc or dioread_nolock and data=journal, fail the mount, instead of printing a warning and continuing (since many user's won't look at dmesg and notice the warning). Also, print a single warning that data=journal implies that delayed allocation is not on by default (since it's not supported), and furthermore that O_DIRECT is not supported. Improve the text in Documentation/filesystems/ext4.txt so this is clear there as well. Similarly, if the dioread_nolock mount option is specified when the file system block size != PAGE_SIZE, fail the mount instead of printing a warning message and ignoring the mount option. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-25ext3/ext4 Documentation: remove bh/nobh since it has been deprecatedLukas Czerner1-16/+7
Bh and nobh mount option has been deprecated in ext4 (206f7ab4f49a2021fcb8687f25395be77711ddee) and in ext3 (4c4d3901225518ed1a4c938ba15ba09842a00770) so remove those options from documentation. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2011-05-01ext4: remove obsolete mount options from ext4's documentationTheodore Ts'o1-4/+0
The block reservation code from ext3 was removed long ago... Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-03-31Fix common misspellingsLucas De Marchi1-2/+2
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-02-21ext4: update ext4 documentationLukas Czerner1-1/+206
Add documentation for mount options and ioctls to Documentation/filesystem/ext4.txt, which has not been udpated for some time. Also add for ext4 sysfs tunables to the Documentation/ABI/testing/sysfs-fs-ext4 file, and fix a few typographical errors in that file. https://bugzilla.kernel.org/show_bug.cgi?id=9423 Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27ext4: add support for lazy inode table initializationLukas Czerner1-0/+14
When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-12-24ext4: Update documentation to correct the inode_readahead_blks option nameFang Wenqi1-1/+1
Per commit 240799cd, the option name for readahead should be inode_readahead_blks, not inode_readahead. Signed-off-by: Fang Wenqi <antonf@turbolinux.com.cn> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-19ext4: make "norecovery" an alias for "noload"Eric Sandeen1-2/+2
Users on the linux-ext4 list recently complained about differences across filesystems w.r.t. how to mount without a journal replay. In the discussion it was noted that xfs's "norecovery" option is perhaps more descriptively accurate than "noload," so let's make that an alias for ext4. Also show this status in /proc/mounts Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-19ext4: make trim/discard optional (and off by default)Eric Sandeen1-0/+6
It is anticipated that when sb_issue_discard starts doing real work on trim-capable devices, we may see issues. Make this mount-time optional, and default it to off until we know that things are working out OK. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-02Revert "ext4: Remove journal_checksum mount option and enable it by default"Linus Torvalds1-1/+7
This reverts commit d0646f7b636d067d715fab52a2ba9c6f0f46b0d7, as requested by Eric Sandeen. It can basically cause an ext4 filesystem to miss recovery (and thus get mounted with errors) if the journal checksum does not match. Quoth Eric: "My hand-wavy hunch about what is happening is that we're finding a bad checksum on the last partially-written transaction, which is not surprising, but if we have a wrapped log and we're doing the initial scan for head/tail, and we abort scanning on that bad checksum, then we are essentially running an unrecovered filesystem. But that's hand-wavy and I need to go look at the code. We lived without journal checksums on by default until now, and at this point they're doing more harm than good, so we should revert the default-changing commit until we can fix it and do some good power-fail testing with the fixes in place." See http://bugzilla.kernel.org/show_bug.cgi?id=14354 for all the gory details. Requested-by: Eric Sandeen <sandeen@redhat.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Alexey Fisher <bug-track@fisher-privat.net> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Mathias Burén <mathias.buren@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-29ext4: Update documentation about quota mount optionsJan Kara1-3/+10
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-18ext4: Update documentation about quota mount optionsJan Kara1-4/+12
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-05ext4: Remove journal_checksum mount option and enable it by defaultTheodore Ts'o1-7/+1
There's no real cost for the journal checksum feature, and we should make sure it is enabled all the time. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-06-13ext4: document the "abort" mount optionTheodore Ts'o1-0/+4
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-06-12trivial: Miscellaneous documentation typo fixesMatt LaPlante1-3/+3
Fix various typos in documentation txts. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-03-28ext4: Regularize mount optionsTheodore Ts'o1-2/+23
Add support for using the mount options "barrier" and "nobarrier", and "auto_da_alloc" and "noauto_da_alloc", which is more consistent than "barrier=<0|1>" or "auto_da_alloc=<0|1>". Most other ext3/ext4 mount options use the foo/nofoo naming convention. We allow the old forms of these mount options for backwards compatibility. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-02-23ext4: Add fine print for the 32000 subdirectory limitTheodore Ts'o1-1/+4
Some poeple are reading the ext4 feature list too literally and create dubious test cases involving very long filenames and 1k blocksize and then complain when they run into an htree-imposed limit. So add fine print to the "fix 32000 subdirectory limit" ext4 feature. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-01-06ext4: Remove "extents" mount optionTheodore Ts'o1-5/+0
This mount option is largely superfluous, and in fact the way it was implemented was buggy; if a filesystem which did not have the extents feature flag was mounted -o extents, the filesystem would attempt to create and use extents-based file even though the extents feature flag was not eabled. The simplest thing to do is to nuke the mount option entirely. It's not all that useful to force the non-creation of new extent-based files if the filesystem can support it. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-01-05ext4: Add mount option to set kjournald's I/O priorityTheodore Ts'o1-0/+7
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com>
2009-01-06ext4: Remove code to create the journal inodeTheodore Ts'o1-4/+0
This code has been obsolete in quite some time, since the supported method for adding a journal inode is to use tune2fs (or to creating new filesystem with a journal via mke2fs or mkfs.ext4). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-01-03ext4: add fsync batch tuning knobsTheodore Ts'o1-0/+29
Add new mount options, min_batch_time and max_batch_time, which controls how long the jbd2 layer should wait for additional filesystem operations to get batched with a synchronous write transaction. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-01-06Update Documentation/filesystems/ext4.txtTheodore Ts'o1-10/+32
Fix paragraph with recommendations on how to tune ext4 for benchmarks. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-17ext4: Update Documentation/filesystems/ext4.txtDiego Calleja1-17/+15
Since Ext4 is supposed to be stable in 2.6.28-rc, ext4's documentation file should be updated. [ More updates also added by Theodore Ts'o. ] Signed-off-by: Diego Calleja <diegocg@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-10ext4: add an option to control error handling on file dataHidehiro Kawai1-0/+5
If the journal doesn't abort when it gets an IO error in file data blocks, the file data corruption will spread silently. Because most of applications and commands do buffered writes without fsync(), they don't notice the IO error. It's scary for mission critical systems. On the other hand, if the journal aborts whenever it gets an IO error in file data blocks, the system will easily become inoperable. So this patch introduces a filesystem option to determine whether it aborts the journal or just call printk() when it gets an IO error in file data. If you mount an ext4 fs with data_err=abort option, it aborts on file data write error. If you mount it with data_err=ignore, it doesn't abort, just call printk(). data_err=ignore is the default. Here is the corresponding patch of the ext3 version: http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374 Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-10-10ext4: Rename ext4dev to ext4Theodore Ts'o1-4/+4
The ext4 filesystem is getting stable enough that it's time to drop the "dev" prefix. Also remove the requirement for the TEST_FILESYS flag. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-09ext4: Use readahead when reading an inode from the inode tableTheodore Ts'o1-0/+6
With modern hard drives, reading 64k takes roughly the same time as reading a 4k block. So request readahead for adjacent inode table blocks to reduce the time it takes when iterating over directories (especially when doing this in htree sort order) in a cold cache case. With this patch, the time it takes to run "git status" on a kernel tree after flushing the caches via "echo 3 > /proc/sys/vm/drop_caches" is reduced by 21%. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-27ext4: Update documentation to remind users to update mke2fs.confTheodore Ts'o1-0/+6
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11ext4: Documention update for new ordered mode and delayed allocationMingming Cao1-7/+14
Adding some documentations for delayed allocation and new ordered mode. Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11ext4: Documentation updates.Jose R. Santos1-44/+62
Some of the information in Documentation/filesystems/ext4.txt is out of date and in need of an update. Signed-off-by: Jose R. Santos <jrs@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-05-26ext4: enable barriers by defaultEric Sandeen1-2/+10
I can't think of any valid reason for ext4 to not use barriers when they are available; I believe this is necessary for filesystem integrity in the face of a volatile write cache on storage. An administrator who trusts that the cache is sufficiently battery- backed (and power supplies are sufficiently redundant, etc...) can always turn it back off again. SuSE has carried such a patch for ext3 for quite some time now. Also document the mount option while we're at it. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-01-29ext4: Add multi block allocator for ext4Alex Tomas1-1/+9
Signed-off-by: Alex Tomas <alex@clusterfs.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-01-28ext4: Add the journal checksum featureGirish Shilamkar1-0/+10
The journal checksum feature adds two new flags i.e JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT and JBD2_FEATURE_COMPAT_CHECKSUM. JBD2_FEATURE_CHECKSUM flag indicates that the commit block contains the checksum for the blocks described by the descriptor blocks. Due to checksums, writing of the commit record no longer needs to be synchronous. Now commit record can be sent to disk without waiting for descriptor blocks to be written to disk. This behavior is controlled using JBD2_FEATURE_ASYNC_COMMIT flag. Older kernels/e2fsck should not be able to recover the journal with _ASYNC_COMMIT hence it is made incompat. The commit header has been extended to hold the checksum along with the type of the checksum. For recovery in pass scan checksums are verified to ensure the sanity and completeness(in case of _ASYNC_COMMIT) of every transaction. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Girish Shilamkar <girish@clusterfs.com> Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com>
2006-10-11[PATCH] Documentation/filesystems/ext4.txtDave Kleikamp1-0/+236
This file, ext4.txt, was put together with information from Andrew Morton, Andreas Dilger, Suparna Bhattacharya, and Ted Ts'o. I copied the mount options, with the exception of "extents", from ext3.txt, so if anyone is aware of anything out-of-date, please let me know. Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>