tree 2e9dfec779989b80010af96287d5d8babbe46796
parent e77751aad1facc4973613a11e2ad98ee4bbb04e1
author Wang Shilong <wangsl.fnst@cn.fujitsu.com> 1388231559 +0800
committer Chris Mason <clm@fb.com> 1390944014 -0800

Btrfs: fix an oops when we fail to relocate tree blocks

During balance test, we hit an oops:
[ 2013.841551] kernel BUG at fs/btrfs/relocation.c:1174!

The problem is that if we fail to relocate tree blocks, we should
update backref cache, otherwise, some pending nodes are not updated
while snapshot check @cache->last_trans is within one transaction
and won't update it and then oops happen.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>