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From: Dave Hansen <dave@linux.vnet.ibm.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>, Al Viro <viro@ZenIV.linux.org.uk>,
	Benjamin Thery <benjamin.thery@bull.net>,
	linux-kernel@vger.kernel.org,
	"Serge E. Hallyn" <serue@us.ibm.com>,
	Al Viro <viro@ftp.linux.org.uk>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Tejun Heo <tj@kernel.org>
Subject: Re: [PATCH 2/3] sysfs: Fix and sysfs_mv_dir by using lock_rename.
Date: Tue, 07 Oct 2008 14:21:09 -0700	[thread overview]
Message-ID: <1223414469.31401.18.camel@nimitz> (raw)
In-Reply-To: <m1vdw465lm.fsf_-_@frodo.ebiederm.org>

On Tue, 2008-10-07 at 03:51 -0700, Eric W. Biederman wrote:
> sysfs_mv_dir picks an arbitrary mutex lock ordering and busy waits
> until it can grab the inode mutexes in that order.  This can dead lock
> on UP systems.
> 
> Instead use the generic lock_rename that guarantees we grab parent
> directories before child directories, so there is not need to spin and
> no chance of deadlock.

This is a vast improvement over what was there before.  Nice!

-- Dave


  parent reply	other threads:[~2008-10-07 21:24 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-22 14:31 sysfs: tagged directories not merged completely yet Benjamin Thery
2008-09-22 15:34 ` Greg KH
2008-09-22 20:24   ` Eric W. Biederman
2008-09-23 14:24   ` Benjamin Thery
2008-09-23 18:23     ` Eric W. Biederman
2008-10-03 10:13       ` Al Viro
2008-10-05  5:32         ` Greg KH
2008-10-07  8:27           ` Eric W. Biederman
2008-10-07 10:47             ` [PATCH 0/3] minor sysfs tagged directory fixes Eric W. Biederman
2008-10-07 10:49               ` [PATCH 1/3] sysfs: Remove lock ordering violation in sysfs_chmod_file Eric W. Biederman
2008-10-07 10:51                 ` [PATCH 2/3] sysfs: Fix and sysfs_mv_dir by using lock_rename Eric W. Biederman
2008-10-07 10:52                   ` [PATCH 3/3] sysfs: Take sysfs_mutex when fetching the root inode Eric W. Biederman
2008-10-07 21:21                   ` Dave Hansen [this message]
2008-10-07 21:19                 ` [PATCH 1/3] sysfs: Remove lock ordering violation in sysfs_chmod_file Dave Hansen
2008-10-07 22:31                   ` Eric W. Biederman
2008-10-07 22:27             ` sysfs: tagged directories not merged completely yet Greg KH
2008-10-07 22:54               ` Serge E. Hallyn
2008-10-07 23:39                 ` Greg KH
2008-10-08  0:12                   ` Serge E. Hallyn
2008-10-08  0:38                     ` Greg KH
2008-10-08 14:18                       ` Serge E. Hallyn
2008-10-07 23:34               ` Tejun Heo
2008-10-14  1:11                 ` Eric W. Biederman
2008-10-14  7:55                   ` Tejun Heo
2008-10-14 12:19                     ` Eric W. Biederman
2008-10-15 11:04                       ` Tejun Heo
2008-10-16 21:58                         ` Eric W. Biederman
2008-10-14 18:53                     ` Serge E. Hallyn
2008-10-15  0:48                       ` Eric W. Biederman
2008-10-15 13:42                         ` Serge E. Hallyn
2008-10-15 13:54                           ` Benjamin Thery
2008-10-08  0:39               ` Eric W. Biederman
2008-10-08  1:29               ` Eric W. Biederman
2008-10-07  8:08         ` Eric W. Biederman
2008-10-07  9:01         ` Daniel Lezcano
2008-10-07  9:12         ` Tejun Heo
2008-10-07 11:56           ` Eric W. Biederman
2008-10-07 12:19             ` Tejun Heo
2008-10-07 23:17               ` Tejun Heo
2008-10-08  0:04                 ` Eric W. Biederman
2008-10-08  0:20                   ` Tejun Heo
2008-10-08  0:58                     ` Eric W. Biederman

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