diff options
| author | Li Zefan <lizefan@huawei.com> | 2013-06-18 06:40:19 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-11 21:35:24 -0400 |
| commit | a09a1b87004a8d574b41e56469005d70fdd2c201 (patch) | |
| tree | 68cb50936087929359a07b071d8738609d445dcb /kernel/workqueue.c | |
| parent | 0297fe5a50da955224e6e26c320383760edce01b (diff) | |
cgroup: fix umount vs cgroup_cfts_commit() race
commit 084457f284abf6789d90509ee11dae383842b23b upstream.
cgroup_cfts_commit() uses dget() to keep cgroup alive after cgroup_mutex
is dropped, but dget() won't prevent cgroupfs from being umounted. When
the race happens, vfs will see some dentries with non-zero refcnt while
umount is in process.
Keep running this:
mount -t cgroup -o blkio xxx /cgroup
umount /cgroup
And this:
modprobe cfq-iosched
rmmod cfs-iosched
After a while, the BUG() in shrink_dcache_for_umount_subtree() may
be triggered:
BUG: Dentry xxx{i=0,n=blkio.yyy} still in use (1) [umount of cgroup cgroup]
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/workqueue.c')
0 files changed, 0 insertions, 0 deletions