ext4: iterate over buffer heads correctly in move_extent_per_page()

guaneryu · tytso · commit 6ffe77bad545 · 2016-03-09T21:37:53.000-05:00
In commit bcff248 ("ext4: don't read blocks from disk after extents being swapped") bh is not updated correctly in the for loop and wrong data has been written to disk. generic/324 catches this on sub-page block size ext4. Fixes: bcff248 ("ext4: don't read blocks from disk after extentsbeing swapped") Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
@@ -390,6 +390,7 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
 		*err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);
 		if (*err < 0)
 			break;
+		bh = bh->b_this_page;
 	}
 	if (!*err)
 		*err = block_commit_write(pagep[0], from, from + replaced_size);

Original file line number	Diff line number	Diff line change
`@@ -390,6 +390,7 @@ move_extent_per_page(struct file o_filp, struct inode donor_inode,`
`390`	`390`	`*err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);`
`391`	`391`	`if (*err < 0)`
`392`	`392`	`break;`
	`393`	`+ bh = bh->b_this_page;`
`393`	`394`	`}`
`394`	`395`	`if (!*err)`
`395`	`396`	`*err = block_commit_write(pagep[0], from, from + replaced_size);`