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From: Tejun Heo <tj@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: ebiederm@xmission.com, gregkh@suse.de,
	linux-kernel@vger.kernel.org, viro@ZenIV.linux.org.uk,
	cornelia.huck@de.ibm.com
Subject: Re: [PATCH] sysfs: Reference sysfs_dirent from sysfs inodes.
Date: Wed, 28 Jan 2009 09:47:19 +0900	[thread overview]
Message-ID: <497FAB17.3080607@kernel.org> (raw)
In-Reply-To: <20090127154437.9e7118f7.akpm@linux-foundation.org>

Andrew Morton wrote:
> On Fri, 23 Jan 2009 15:33:48 +0900
> Tejun Heo <tj@kernel.org> wrote:
> 
>> Eric W. Biederman wrote:
>>> The sysfs_dirent serves as both an inode and a directory entry
>>> for sysfs.  To prevent the sysfs inode numbers from being freed
>>> prematurely hold a reference to sysfs_dirent from the sysfs inode.
>>>
>>> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
>> Thanks for working on this.  Can you please add a comment explaining
>> it on top of sysfs_delete_inode()?
> 
> Like this?
> 
> --- a/fs/sysfs/inode.c~sysfs-reference-sysfs_dirent-from-sysfs-inodes-fix
> +++ a/fs/sysfs/inode.c
> @@ -215,6 +215,13 @@ struct inode * sysfs_get_inode(struct sy
>  	return inode;
>  }
>  
> +/*
> + * The sysfs_dirent serves as both an inode and a directory entry for sysfs.
> + * To prevent the sysfs inode numbers from being freed prematurely we take a
> + * reference to sysfs_dirent from the sysfs inode.  A
> + * super_operations.delete_inode() implementation is needed to drop that
> + * reference upon inode destruction.
> + */
>  void sysfs_delete_inode(struct inode *inode)
>  {
>  	struct sysfs_dirent *sd  = inode->i_private;

Yeap, looks good to me.  :-)

Thanks.

-- 
tejun


  reply	other threads:[~2009-01-28  1:01 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-21 19:55 [PATCH] sysfs: Take sysfs_mutex when fetching the root inode Eric W. Biederman
2009-01-22 16:49 ` [PATCH] sysfs: Reference sysfs_dirent from sysfs inodes Eric W. Biederman
2009-01-23  6:33   ` Tejun Heo
2009-01-27 23:44     ` Andrew Morton
2009-01-28  0:47       ` Tejun Heo [this message]
2009-02-02 17:03         ` Eric W. Biederman
2009-01-23  6:28 ` [PATCH] sysfs: Take sysfs_mutex when fetching the root inode Tejun Heo

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