Alexander and David, This patch fixed the problem which was reported more than a mounth ago https://patchwork.kernel.org/patch/10610671/ Now this code is in the linux-next and the problem blocks running CRIU tests on the linux next kernels: https://travis-ci.org/avagin/linux/builds Thanks, Andrei On Fri, Dec 28, 2018 at 04:04:00PM -0800, Andrei Vagin 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 > > kernel/cgroup/cgroup.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c > index fb0717696895..f63974a3725f 100644 > --- a/kernel/cgroup/cgroup.c > +++ b/kernel/cgroup/cgroup.c > @@ -2047,6 +2047,9 @@ int cgroup_do_get_tree(struct fs_context *fc) > ret = 0; > if (ctx->kfc.new_sb_created) > goto out_cgrp; > + else > + cgroup_put(&ctx->root->cgrp); > + > apply_cgroup_root_flags(ctx->flags); > return 0; > > -- > 2.17.2 >