From: Tejun Heo Date: Wed, 14 May 2014 13:15:00 +0000 (-0400) Subject: cgroup: use restart_syscall() for mount retries X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a015edd26e28afe225cdd04f25794bd2b3bbe2da;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git cgroup: use restart_syscall() for mount retries 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. v2: The original patch forgot to free memory allocated for @opts. Fixed. Caught by Li Zefan. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 457e52705f56..f36fd9c15b3a 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 +1740,8 @@ retry: if (!atomic_inc_not_zero(&root->cgrp.refcnt)) { mutex_unlock(&cgroup_mutex); msleep(10); - mutex_lock(&cgroup_mutex); - goto retry; + ret = restart_syscall(); + goto out_free; } ret = 0; @@ -1772,7 +1772,7 @@ retry: out_unlock: mutex_unlock(&cgroup_mutex); - +out_free: kfree(opts.release_agent); kfree(opts.name);