1 files changed, 72 insertions, 70 deletions

diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
index d7d430a6f130..c352fff88a5e 100644
--- a/fs/f2fs/verity.c
+++ b/fs/f2fs/verity.c
@@ -29,6 +29,8 @@
 #include "f2fs.h"
 #include "xattr.h"
 
+#define F2FS_VERIFY_VER	(1)
+
 static inline loff_t f2fs_verity_metadata_pos(const struct inode *inode)
 {
 	return round_up(inode->i_size, 65536);
@@ -45,16 +47,13 @@ static int pagecache_read(struct inode *inode, void *buf, size_t count,
 		size_t n = min_t(size_t, count,
 				 PAGE_SIZE - offset_in_page(pos));
 		struct page *page;
-		void *addr;
 
 		page = read_mapping_page(inode->i_mapping, pos >> PAGE_SHIFT,
 					 NULL);
 		if (IS_ERR(page))
 			return PTR_ERR(page);
 
-		addr = kmap_atomic(page);
-		memcpy(buf, addr + offset_in_page(pos), n);
-		kunmap_atomic(addr);
+		memcpy_from_page(buf, page, offset_in_page(pos), n);
 
 		put_page(page);
 
@@ -72,6 +71,9 @@ static int pagecache_read(struct inode *inode, void *buf, size_t count,
 static int pagecache_write(struct inode *inode, const void *buf, size_t count,
 			   loff_t pos)
 {
+	struct address_space *mapping = inode->i_mapping;
+	const struct address_space_operations *aops = mapping->a_ops;
+
 	if (pos + count > inode->i_sb->s_maxbytes)
 		return -EFBIG;
 
@@ -80,20 +82,15 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count,
 				 PAGE_SIZE - offset_in_page(pos));
 		struct page *page;
 		void *fsdata;
-		void *addr;
 		int res;
 
-		res = pagecache_write_begin(NULL, inode->i_mapping, pos, n, 0,
-					    &page, &fsdata);
+		res = aops->write_begin(NULL, mapping, pos, n, &page, &fsdata);
 		if (res)
 			return res;
 
-		addr = kmap_atomic(page);
-		memcpy(addr + offset_in_page(pos), buf, n);
-		kunmap_atomic(addr);
+		memcpy_to_page(page, offset_in_page(pos), buf, n);
 
-		res = pagecache_write_end(NULL, inode->i_mapping, pos, n, n,
-					  page, fsdata);
+		res = aops->write_end(NULL, mapping, pos, n, n, page, fsdata);
 		if (res < 0)
 			return res;
 		if (res != n)
@@ -126,7 +123,7 @@ static int f2fs_begin_enable_verity(struct file *filp)
 	if (f2fs_verity_in_progress(inode))
 		return -EBUSY;
 
-	if (f2fs_is_atomic_file(inode) || f2fs_is_volatile_file(inode))
+	if (f2fs_is_atomic_file(inode))
 		return -EOPNOTSUPP;
 
 	/*
@@ -134,7 +131,7 @@ static int f2fs_begin_enable_verity(struct file *filp)
 	 * here and not rely on ->open() doing it.  This must be done before
 	 * evicting the inline data.
 	 */
-	err = dquot_initialize(inode);
+	err = f2fs_dquot_initialize(inode);
 	if (err)
 		return err;
 
@@ -150,40 +147,73 @@ static int f2fs_end_enable_verity(struct file *filp, const void *desc,
 				  size_t desc_size, u64 merkle_tree_size)
 {
 	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	u64 desc_pos = f2fs_verity_metadata_pos(inode) + merkle_tree_size;
 	struct fsverity_descriptor_location dloc = {
-		.version = cpu_to_le32(1),
+		.version = cpu_to_le32(F2FS_VERIFY_VER),
 		.size = cpu_to_le32(desc_size),
 		.pos = cpu_to_le64(desc_pos),
 	};
-	int err = 0;
+	int err = 0, err2 = 0;
 
-	if (desc != NULL) {
-		/* Succeeded; write the verity descriptor. */
-		err = pagecache_write(inode, desc, desc_size, desc_pos);
+	/*
+	 * If an error already occurred (which fs/verity/ signals by passing
+	 * desc == NULL), then only clean-up is needed.
+	 */
+	if (desc == NULL)
+		goto cleanup;
 
-		/* Write all pages before clearing FI_VERITY_IN_PROGRESS. */
-		if (!err)
-			err = filemap_write_and_wait(inode->i_mapping);
-	}
+	/* Append the verity descriptor. */
+	err = pagecache_write(inode, desc, desc_size, desc_pos);
+	if (err)
+		goto cleanup;
 
-	/* If we failed, truncate anything we wrote past i_size. */
-	if (desc == NULL || err)
-		f2fs_truncate(inode);
+	/*
+	 * Write all pages (both data and verity metadata).  Note that this must
+	 * happen before clearing FI_VERITY_IN_PROGRESS; otherwise pages beyond
+	 * i_size won't be written properly.  For crash consistency, this also
+	 * must happen before the verity inode flag gets persisted.
+	 */
+	err = filemap_write_and_wait(inode->i_mapping);
+	if (err)
+		goto cleanup;
+
+	/* Set the verity xattr. */
+	err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_VERITY,
+			    F2FS_XATTR_NAME_VERITY, &dloc, sizeof(dloc),
+			    NULL, XATTR_CREATE);
+	if (err)
+		goto cleanup;
+
+	/* Finally, set the verity inode flag. */
+	file_set_verity(inode);
+	f2fs_set_inode_flags(inode);
+	f2fs_mark_inode_dirty_sync(inode, true);
 
 	clear_inode_flag(inode, FI_VERITY_IN_PROGRESS);
+	return 0;
 
-	if (desc != NULL && !err) {
-		err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_VERITY,
-				    F2FS_XATTR_NAME_VERITY, &dloc, sizeof(dloc),
-				    NULL, XATTR_CREATE);
-		if (!err) {
-			file_set_verity(inode);
-			f2fs_set_inode_flags(inode);
-			f2fs_mark_inode_dirty_sync(inode, true);
-		}
+cleanup:
+	/*
+	 * Verity failed to be enabled, so clean up by truncating any verity
+	 * metadata that was written beyond i_size (both from cache and from
+	 * disk) and clearing FI_VERITY_IN_PROGRESS.
+	 *
+	 * Taking i_gc_rwsem[WRITE] is needed to stop f2fs garbage collection
+	 * from re-instantiating cached pages we are truncating (since unlike
+	 * normal file accesses, garbage collection isn't limited by i_size).
+	 */
+	f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+	truncate_inode_pages(inode->i_mapping, inode->i_size);
+	err2 = f2fs_truncate(inode);
+	if (err2) {
+		f2fs_err(sbi, "Truncating verity metadata failed (errno=%d)",
+			 err2);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
 	}
-	return err;
+	f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+	clear_inode_flag(inode, FI_VERITY_IN_PROGRESS);
+	return err ?: err2;
 }
 
 static int f2fs_get_verity_descriptor(struct inode *inode, void *buf,
@@ -199,7 +229,7 @@ static int f2fs_get_verity_descriptor(struct inode *inode, void *buf,
 			    F2FS_XATTR_NAME_VERITY, &dloc, sizeof(dloc), NULL);
 	if (res < 0 && res != -ERANGE)
 		return res;
-	if (res != sizeof(dloc) || dloc.version != cpu_to_le32(1)) {
+	if (res != sizeof(dloc) || dloc.version != cpu_to_le32(F2FS_VERIFY_VER)) {
 		f2fs_warn(F2FS_I_SB(inode), "unknown verity xattr format");
 		return -EINVAL;
 	}
@@ -210,6 +240,8 @@ static int f2fs_get_verity_descriptor(struct inode *inode, void *buf,
 	if (pos + size < pos || pos + size > inode->i_sb->s_maxbytes ||
 	    pos < f2fs_verity_metadata_pos(inode) || size > INT_MAX) {
 		f2fs_warn(F2FS_I_SB(inode), "invalid verity xattr");
+		f2fs_handle_error(F2FS_I_SB(inode),
+				ERROR_CORRUPTED_VERITY_XATTR);
 		return -EFSCORRUPTED;
 	}
 	if (buf_size) {
@@ -222,37 +254,6 @@ static int f2fs_get_verity_descriptor(struct inode *inode, void *buf,
 	return size;
 }
 
-/*
- * Prefetch some pages from the file's Merkle tree.
- *
- * This is basically a stripped-down version of __do_page_cache_readahead()
- * which works on pages past i_size.
- */
-static void f2fs_merkle_tree_readahead(struct address_space *mapping,
-				       pgoff_t start_index, unsigned long count)
-{
-	LIST_HEAD(pages);
-	unsigned int nr_pages = 0;
-	struct page *page;
-	pgoff_t index;
-	struct blk_plug plug;
-
-	for (index = start_index; index < start_index + count; index++) {
-		page = xa_load(&mapping->i_pages, index);
-		if (!page || xa_is_value(page)) {
-			page = __page_cache_alloc(readahead_gfp_mask(mapping));
-			if (!page)
-				break;
-			page->index = index;
-			list_add(&page->lru, &pages);
-			nr_pages++;
-		}
-	}
-	blk_start_plug(&plug);
-	f2fs_mpage_readpages(mapping, &pages, NULL, nr_pages, true);
-	blk_finish_plug(&plug);
-}
-
 static struct page *f2fs_read_merkle_tree_page(struct inode *inode,
 					       pgoff_t index,
 					       unsigned long num_ra_pages)
@@ -263,11 +264,12 @@ static struct page *f2fs_read_merkle_tree_page(struct inode *inode,
 
 	page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED);
 	if (!page || !PageUptodate(page)) {
+		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
+
 		if (page)
 			put_page(page);
 		else if (num_ra_pages > 1)
-			f2fs_merkle_tree_readahead(inode->i_mapping, index,
-						   num_ra_pages);
+			page_cache_ra_unbounded(&ractl, num_ra_pages, 0);
 		page = read_mapping_page(inode->i_mapping, index, NULL);
 	}
 	return page;