Andrei Vagin <avagin@xxxxxxxxx> wrote:
> It looks like the c6b3d5bcd67c ("cgroup: fix top cgroup refcnt leak")
> commit was reverted by mistake.
>
> $ mkdir /tmp/cgroup
> $ mkdir /tmp/cgroup2
> $ mount -t cgroup -o none,name=test test /tmp/cgroup
> $ mount -t cgroup -o none,name=test test /tmp/cgroup2
> $ umount /tmp/cgroup
> $ umount /tmp/cgroup2
> $ cat /proc/self/cgroup | grep test
> 12:name=test:/
>
> You can see the test cgroup was not freed.
>
> Cc: Li Zefan <lizefan@xxxxxxxxxx>
> Fixes: aea3f2676c83 ("kernfs, sysfs, cgroup, intel_rdt: Support fs_context")
> Signed-off-by: Andrei Vagin <avagin@xxxxxxxxx>
> ---
>
> v2: clean up code and add the vfs/for-next tag
> v3: fix a reference leak when kernfs_node_dentry fails
> v4: call deactivate_locked_super() in a error case
> v5: don't dereference fc->root after dput()
>
> kernel/cgroup/cgroup.c | 25 ++++++++++++++++++-------
> 1 file changed, 18 insertions(+), 7 deletions(-)
This patch doesn't work either.
percpu ref (css_release) <= 0 (0) after switching to atomic
RIP: 0010:percpu_ref_switch_to_atomic_rcu+0x90/0x1a0
Btw, note that the subject says "v4" but the changelog says "v5".
David
