Commit a39f7521 authored Sep 11, 2011 by Miao Xie Committed by Chris Mason Sep 11, 2011

Btrfs: fix wrong nbytes information of the inode



If we write some data into the data hole of the file(no preallocation for this
hole), Btrfs will allocate some disk space, and update nbytes of the inode, but
the other element--disk_i_size needn't be updated. At this condition, we must
update inode metadata though disk_i_size is not changed(btrfs_ordered_update_i_size()
return 1).

 # mkfs.btrfs /dev/sdb1
 # mount /dev/sdb1 /mnt
 # touch /mnt/a
 # truncate -s 856002 /mnt/a
 # dd if=/dev/zero of=/mnt/a bs=4K count=1 conv=nocreat,notrunc
 # umount /mnt
 # btrfsck /dev/sdb1
 root 5 inode 257 errors 400
 found 32768 bytes used err is 1

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent 0c1a98c8

fs/btrfs/inode.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1786,7 +1786,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
		&ordered_extent->list);

		ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
		if (!ret) {
		if (!ret \|\| !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
		ret = btrfs_update_inode(trans, root, inode);
		BUG_ON(ret);
		}
		@@ -5788,7 +5788,7 @@ again:

		add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
		ret = btrfs_ordered_update_i_size(inode, 0, ordered);
		if (!ret)
		if (!ret \|\| !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags))
		btrfs_update_inode(trans, root, inode);
		ret = 0;
		out_unlock:

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