Messages in this thread | | | Date | Sat, 14 Jul 2012 13:08:52 +0100 | From | Al Viro <> | Subject | Re: [PATCH 2/2] cgroup: fix cgroup hierarchy umount race |
| |
On Sat, Jul 07, 2012 at 04:46:59PM -0700, 'Tejun Heo' wrote: > Fix it by holding an extra superblock->s_active reference across > dput() from css release, which is the dput() path added by 48ddbe1946 > and the only one which doesn't hold an extra s_active ref across the > final cgroup dput().
> @@ -3883,8 +3883,12 @@ static void css_dput_fn(struct work_struct *work) > { > struct cgroup_subsys_state *css = > container_of(work, struct cgroup_subsys_state, dput_work); > + struct dentry *dentry = css->cgroup->dentry; > + struct super_block *sb = dentry->d_sb; > > - dput(css->cgroup->dentry); > + atomic_inc(&sb->s_active); > + dput(dentry); > + deactivate_super(sb); > }
While we are at it, what guarantees that css->dput_work will complete before css->cgroup or the object containing css get freed under us?
| |