Date: Wed, 9 Jan 2008 16:57:48 +0100
From: Cornelia Huck <cornelia.huck@de.ibm.com>
To: Tejun Heo <htejun@gmail.com>
Cc: Gabor Gombas <gombasg@sztaki.hu>, Al Viro <viro@ZenIV.linux.org.uk>,
       Dave Young <hidave.darkstar@gmail.com>, linux-kernel@vger.kernel.org,
       bluez-devel@lists.sourceforge.net, kay.sievers@vrfy.org,
       Greg KH <greg@kroah.com>
Subject: Re: [Bluez-devel] Oops involving RFCOMM and sysfs
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On Wed, 09 Jan 2008 18:16:02 +0900,
Tejun Heo <htejun@gmail.com> wrote:

> This isn't supported.  sysfs doesn't allow parents to die first and the
> dangling children to be salvaged using sysfs_move().

But (with the sysfs bugs fixed) it will return an error, won't it? It
seems the bluetooth code is rather optimistic with never checking
device_move()'s return code.

> 
> 2. Which in turn exposes three bugs in sysfs
> 	- sysfs_lookup() returning NULL on negative lookup.  sysfs
> 	  code requires that all negative dentries are shot down.
> 	  lookup should return -ENOENT instead of NULL.
> 	- in move and rename, error handling is wrong.  It ends up
> 	  passing ERR_PTR() values to dput().
> 	- there was an extra dput() in sysfs_move_dir().

Ups, seem to have copied that from some old version of
sysfs_rename_dir()...

> 
> The attached patch fixes all sysfs bugs and removes the oops. 

Looks OK at first glance.
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