lkml.org 
[lkml]   [2013]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] devtmpfs: Calling delete_path() only when necessary
From
2013/12/9 Axel Lin <axel.lin@ingics.com>:
> 2013/12/9 Greg Kroah-Hartman <gregkh@linuxfoundation.org>:
>> On Mon, Dec 09, 2013 at 04:54:29PM +0800, Axel Lin wrote:
>>> 2013/12/9 Greg Kroah-Hartman <gregkh@linuxfoundation.org>:
>>> > On Wed, Dec 04, 2013 at 02:44:14PM +0800, Axel Lin wrote:
>>> >> 2013/12/4 Rob Landley <rob@landley.net>:
>>> >> > On 11/16/2013 02:15:23 AM, Axel Lin wrote:
>>> >> >>
>>> >> >> The deleted variable is always 1 in current code.
>>> >> >> Initialize deleted variable to be 0, so delete_path() will be called only
>>> >> >> when
>>> >> >> necessary.
>>> >> >>
>>> >> >> Signed-off-by: Axel Lin <axel.lin@ingics.com>
>>> >> >
>>> >> >
>>> >> > I'm not seeing this in linux-next, or a reply on the web archive. Assuming
>>> >> > nobody's objected to this, you might want to forward it to
>>> >> > trivial@kernel.org.
>>> >> >
>>> >> > That said, you could describe what it _does_ a little more?
>>> >>
>>> >> I was expecting Greg to pick up this patch.
>>> >>
>>> >> I thought the description is pretty clear.
>>> >> What the patch does is changing the init value of deleted variable to 0.
>>> >> The intention of this change is to avoid unnecessary delete_path() call.
>>> >
>>> > I agree the logic is a bit odd here, but are you seeing an "unnecessary"
>>> > delete_path() call happening? The code has always been like this from
>>> > what I can tell...
>>>
>>> Honestly, I havn't see the "unnecessary" delete_path() call happening druing my
>>> test. I look at the code when I was debugging a hangup issue.
>>> (In the end, I think the issue is not related to the devtmpfs code.)
>>> But I found the logic for the deleted variable looks odd.
>>> There are below possible (unlikely) case:
>>> When strchr(nodename, '/') != 0 and
>>> 1. If dentry->d_inode is NULL
>>> 2. vfs_getattr returns error
>>> 3. vfs_unlink returns error except -ENOENT.
>>>
>>> In these cases, delete_path() will fail anyway.
>>>
>>> Although this is a unlikely case, and I know the code is there since initial
>>> commit. But I think it's still good to fix it.
>>
>> Have you tested your patch to verify nothing breaks?
> Yes. I have this patch in my local build image since the day I sent the patch.
Hi Greg,
If you want more testing for this patch to ensure nothing break,
I think maybe Fengguang can also help to test it.

Hi, Fengguang
Can you help to add this patch to your test systems?
It's a one-line change, you can find the patch at
https://patchwork.kernel.org/patch/3192361/

Regards,
Axel


\
 
 \ /
  Last update: 2013-12-10 07:41    [W:0.055 / U:0.708 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site