Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-09 06:33:34 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Btrfs: fix wrong write offset when replacing a device

Browse Source 
Miao Xie reported the following issue:

The filesystem was corrupted after we did a device replace.

Steps to reproduce:
 # mkfs.btrfs -f -m single -d raid10 <device0>..<device3>
 # mount <device0> <mnt>
 # btrfs replace start -rfB 1 <device4> <mnt>
 # umount <mnt>
 # btrfsck <device4>

The reason for the issue is that we changed the write offset by mistake,
introduced by commit 625f1c8dc.

We read the data from the source device at first, and then write the
data into the corresponding place of the new device. In order to
implement the "-r" option, the source location is remapped using
btrfs_map_block(). The read takes place on the mapped location, and
the write needs to take place on the unmapped location. Currently
the write is using the mapped location, and this commit changes it
back by undoing the change to the write address that the aforementioned
commit added by mistake.

Reported-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Stefan Behrens 2013-07-04 16:14:23 +02:00 committed by Josef Bacik
parent d29a9f629e
commit 115930cb2d
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/btrfs/scrub.c
View File

@ -2495,7 +2495,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
ret = scrub_extent(sctx, extent_logical, extent_len,
extent_physical, extent_dev, flags,
generation, extent_mirror_num,
extent_physical);
extent_logical - logical + physical);
if (ret)
goto out;