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From: Li Zefan <lizf@cn.fujitsu.com>
To: Paul Menage <menage@google.com>
Cc: pj@sgi.com, xemul@openvz.org, balbir@in.ibm.com,
	serue@us.ibm.com, akpm@linux-foundation.org,
	linux-kernel@vger.kernel.org,
	containers@lists.linux-foundation.org
Subject: Re: [RFC/PATCH 1/8]: CGroup Files: Add locking mode to cgroups control files
Date: Wed, 14 May 2008 09:30:40 +0800	[thread overview]
Message-ID: <482A40C0.8030708@cn.fujitsu.com> (raw)
In-Reply-To: <6599ad830805131407y3d94016cn773ba21a42b6098c@mail.gmail.com>

>>  > @@ -1518,16 +1580,21 @@ static ssize_t cgroup_file_read(struct f
>>  >       struct cftype *cft = __d_cft(file->f_dentry);
>>  >       struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
>>  >
>>  > -     if (!cft || cgroup_is_removed(cgrp))
>>  > +     if (cgroup_is_removed(cgrp))
>>  >               return -ENODEV;
>>  >
>>
>>  This check seems redundant now.
>>
> 
> It's not needed for safety, but it doesn't seem to hurt to check
> cgroup_is_removed() prior to doing any copying, since we'll fail after
> copying anyway if cgroup_is_removed() returns true (once we've taken
> any relevant locks).
> 

It's a bit odd to me that cgroup_is_removed() is removed in cgroup_file_write(),
but it's ressered here.


  reply	other threads:[~2008-05-14  1:32 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-05-13  6:37 [RFC/PATCH 0/8]: CGroup Files: Clean up locking and boilerplate menage
2008-05-13  6:37 ` [RFC/PATCH 1/8]: CGroup Files: Add locking mode to cgroups control files menage
2008-05-13  9:23   ` Li Zefan
2008-05-13 21:07     ` Paul Menage
2008-05-14  1:30       ` Li Zefan [this message]
2008-05-14  1:40         ` Paul Menage
2008-05-13 20:01   ` Andrew Morton
2008-05-13 20:38     ` Matthew Helsley
2008-05-13 20:43       ` Andrew Morton
2008-05-13 21:17     ` Paul Menage
2008-05-13 21:32       ` Andrew Morton
2008-05-13 21:46         ` Paul Menage
2008-05-14  1:59         ` Paul Jackson
2008-05-13  6:37 ` [RFC/PATCH 2/8]: CGroup Files: Add a cgroup write_string control file method menage
2008-05-13 20:07   ` Andrew Morton
2008-05-13 21:01     ` Paul Menage
2008-05-13 20:44   ` Matt Helsley
2008-05-13  6:37 ` [RFC/PATCH 3/8]: CGroup Files: Move the release_agent file to use typed handlers menage
2008-05-13 20:08   ` Andrew Morton
2008-05-13 21:32     ` Paul Menage
2008-05-13  6:37 ` [RFC/PATCH 4/8]: CGroup Files: Move notify_on_release file to separate write handler menage
2008-05-13  6:37 ` [RFC/PATCH 5/8]: CGroup Files: Turn attach_task_by_pid directly into a cgroup " menage
2008-05-13  6:37 ` [RFC/PATCH 6/8]: CGroup Files: Remove cpuset_common_file_write() menage
2008-05-13 20:11   ` Andrew Morton
2008-05-13 21:27     ` Paul Menage
2008-05-13  6:37 ` [RFC/PATCH 7/8]: CGroup Files: Convert devcgroup_access_write() into a cgroup write_string() handler menage
2008-05-13  6:37 ` [RFC/PATCH 8/8]: CGroup Files: Convert res_counter_write() to be a cgroups " menage

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