From: Kamezawa Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
mhocko-AlSwsSmVLrQ@public.gmane.org,
hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Subject: Re: [PATCH 3/8] cgroup: use cgroup_lock_live_group(parent) in cgroup_create()
Date: Fri, 02 Nov 2012 19:03:46 +0900 [thread overview]
Message-ID: <50939A82.8080203@jp.fujitsu.com> (raw)
In-Reply-To: <1351712650-23709-4-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
(2012/11/01 4:44), Tejun Heo wrote:
> This patch makes cgroup_create() fail if @parent is marked removed.
> This is to prepare for further updates to cgroup_rmdir() path.
>
> Note that this change isn't strictly necessary. cgroup can only be
> created via mkdir and the removed marking and dentry removal happen
> without releasing cgroup_mutex, so cgroup_create() can never race with
> cgroup_rmdir(). Even after the scheduled updates to cgroup_rmdir(),
> cgroup_mkdir() and cgroup_rmdir() are synchronized by i_mutex
> rendering the added liveliness check unnecessary.
>
> Do it anyway such that locking is contained inside cgroup proper and
> we don't get nasty surprises if we ever grow another caller of
> cgroup_create().
>
> Signed-off-by: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Reviewed-by: Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
next prev parent reply other threads:[~2012-11-02 10:03 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-31 19:44 [PATCHSET RESEND v2] cgroup: simplify cgroup removal path Tejun Heo
[not found] ` <1351712650-23709-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-10-31 19:44 ` [PATCH 1/8] cgroup: kill cgroup_subsys->__DEPRECATED_clear_css_refs Tejun Heo
[not found] ` <1351712650-23709-2-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-10-31 20:08 ` Michal Hocko
[not found] ` <20121031200859.GE1271-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-10-31 20:11 ` Tejun Heo
[not found] ` <CAOS58YPbYoMJ1+3uRfK_ZERyZoaby=FPW7uTpp8dVOSgYC8Mrw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-10-31 20:14 ` Michal Hocko
[not found] ` <20121031201415.GG1271-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-10-31 20:24 ` Tejun Heo
[not found] ` <20121031202400.GT2945-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-10-31 20:49 ` Michal Hocko
2012-11-02 10:01 ` Kamezawa Hiroyuki
2012-10-31 20:12 ` Michal Hocko
[not found] ` <20121031201227.GF1271-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-10-31 20:14 ` Tejun Heo
[not found] ` <CAOS58YOHjLyKFeah+h+qOrAWvfi1O5eL7m-AMbqAdcP=EOFb6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-10-31 21:23 ` Michal Hocko
2012-11-05 5:34 ` Li Zefan
2012-10-31 19:44 ` [PATCH 2/8] cgroup: kill CSS_REMOVED Tejun Heo
[not found] ` <1351712650-23709-3-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-11-02 10:02 ` Kamezawa Hiroyuki
2012-11-05 5:33 ` Li Zefan
2012-10-31 19:44 ` [PATCH 3/8] cgroup: use cgroup_lock_live_group(parent) in cgroup_create() Tejun Heo
[not found] ` <1351712650-23709-4-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-11-02 10:03 ` Kamezawa Hiroyuki [this message]
2012-11-05 5:36 ` Li Zefan
2012-10-31 19:44 ` [PATCH 5/8] cgroup: remove CGRP_WAIT_ON_RMDIR, cgroup_exclude_rmdir() and cgroup_release_and_wakeup_rmdir() Tejun Heo
[not found] ` <1351712650-23709-6-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-11-02 10:20 ` Kamezawa Hiroyuki
2012-11-05 5:40 ` Li Zefan
2012-10-31 19:44 ` [PATCH 6/8] memcg: make mem_cgroup_reparent_charges non failing Tejun Heo
[not found] ` <1351712650-23709-7-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-11-02 10:21 ` Kamezawa Hiroyuki
2012-10-31 19:44 ` [PATCH 7/8] hugetlb: do not fail in hugetlb_cgroup_pre_destroy Tejun Heo
[not found] ` <1351712650-23709-8-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-11-02 10:23 ` Kamezawa Hiroyuki
2012-11-05 17:30 ` [PATCHSET RESEND v2] cgroup: simplify cgroup removal path Tejun Heo
[not found] ` <20121105173024.GA19354-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2012-11-05 18:39 ` Michal Hocko
2012-10-31 19:44 ` [PATCH 4/8] cgroup: deactivate CSS's and mark cgroup dead before invoking ->pre_destroy() Tejun Heo
[not found] ` <1351712650-23709-5-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-10-31 21:23 ` Michal Hocko
[not found] ` <20121031212359.GC5286-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-10-31 21:27 ` Tejun Heo
[not found] ` <20121031212725.GA2945-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-11-01 8:58 ` Michal Hocko
2012-11-02 10:05 ` Kamezawa Hiroyuki
2012-11-05 5:37 ` Li Zefan
2012-10-31 19:44 ` [PATCH 8/8] cgroup: make ->pre_destroy() return void Tejun Heo
[not found] ` <1351712650-23709-9-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-10-31 21:23 ` Michal Hocko
2012-11-02 10:24 ` Kamezawa Hiroyuki
2012-11-05 5:41 ` Li Zefan
-- strict thread matches above, loose matches on Subject: below --
2012-10-31 18:16 [PATCHSET v2] cgroup: simplify cgroup removal path Tejun Heo
2012-10-31 18:16 ` [PATCH 3/8] cgroup: use cgroup_lock_live_group(parent) in cgroup_create() Tejun Heo
2012-10-31 4:22 [PATCHSET] cgroup: simplify cgroup removal path Tejun Heo
[not found] ` <1351657365-25055-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-10-31 4:22 ` [PATCH 3/8] cgroup: use cgroup_lock_live_group(parent) in cgroup_create() Tejun Heo
[not found] ` <1351657365-25055-4-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2012-10-31 15:55 ` Michal Hocko
[not found] ` <20121031155514.GD22809-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-10-31 17:04 ` Tejun Heo
[not found] ` <20121031170431.GF2945-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-11-01 9:16 ` Michal Hocko
[not found] ` <20121101091644.GA8533-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-11-01 14:52 ` Tejun Heo
[not found] ` <CAOS58YM+kRtspVUzmnSmOmrDoNS_kF6KA02zWGxqH5FUcRWo1Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-11-01 15:05 ` Michal Hocko
[not found] ` <20121101150532.GA5065-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-11-01 15:15 ` Michal Hocko
[not found] ` <20121101151556.GB5065-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2012-11-01 15:43 ` Tejun Heo
2012-11-02 9:37 ` Kamezawa Hiroyuki
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