cgroup_mount() uses dumb delay-and-retry logic to wait for cgroup_root which is being destroyed. The retry currently loops inside cgroup_mount() proper. This patch makes it return with restart_syscall() instead so that retry travels out to userland boundary. This slightly simplifies the logic and more importantly makes the retry logic behave better when the wait for some reason becomes lengthy or infinite by allowing the operation to be suspended or terminated from userland. Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> --- kernel/cgroup.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 3083c5a..2755f33 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1681,7 +1681,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, ret = parse_cgroupfs_options(data, &opts); if (ret) goto out_unlock; -retry: + /* look for a matching existing root */ if (!opts.subsys_mask && !opts.none && !opts.name) { cgrp_dfl_root_visible = true; @@ -1740,8 +1740,7 @@ retry: if (!atomic_inc_not_zero(&root->cgrp.refcnt)) { mutex_unlock(&cgroup_mutex); msleep(10); - mutex_lock(&cgroup_mutex); - goto retry; + return ERR_PTR(restart_syscall()); } ret = 0; -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html