]> git.openfabrics.org - ~shefty/rdma-dev.git/commit
Btrfs: fix a bug of per-file nocow
authorLiu Bo <bo.li.liu@oracle.com>
Tue, 11 Sep 2012 14:33:50 +0000 (08:33 -0600)
committerChris Mason <chris.mason@fusionio.com>
Mon, 17 Dec 2012 19:48:21 +0000 (14:48 -0500)
commit213490b301773ea9c6fb89a86424a6901fcdd069
tree5f5d1df3c7de78ccb75d0d41a281103d177c72b8
parent9c52057c698fb96f8f07e7a4bcf4801a092bda89
Btrfs: fix a bug of per-file nocow

Users report a bug, the reproducer is:
$ mkfs.btrfs /dev/loop0
$ mount /dev/loop0 /mnt/btrfs/
$ mkdir /mnt/btrfs/dir
$ chattr +C /mnt/btrfs/dir/
$ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=10;
$ lsattr /mnt/btrfs/dir/foo
---------------C- /mnt/btrfs/dir/foo
$ filefrag /mnt/btrfs/dir/foo
/mnt/btrfs/dir/foo: 1 extent found    ---> an extent
$ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=1 seek=5 conv=notrunc,nocreat; sync
$ filefrag /mnt/btrfs/dir/foo
/mnt/btrfs/dir/foo: 3 extents found   ---> with nocow, btrfs breaks the extent into three parts

The new created file should not only inherit the NODATACOW flag, but also
honor NODATASUM flag, because we must do COW on a file extent with checksum.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
fs/btrfs/inode.c
fs/btrfs/ioctl.c