ocfs2: fix a tiny race when running dirop_fileop_racer
When running dirop_fileop_racer we found a dead lock case.
2 nodes, say Node A and Node B, mount the same ocfs2 volume. Create
/race/16/1 in the filesystem, and let the inode number of dir 16 is less
than the inode number of dir race.
Node A Node B
mv /race/16/1 /race/
right after Node A has got the
EX mode of /race/16/, and tries to
get EX mode of /race
ls /race/16/
In this case, Node A has got the EX mode of /race/16/, and wants to get EX
mode of /race/. Node B has got the PR mode of /race/, and wants to get
the PR mode of /race/16/. Since EX and PR are mutually exclusive, dead
lock happens.
This patch fixes this case by locking in ancestor order before trying
inode number order.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 files changed