lkml.org 
[lkml]   [2016]   [Jul]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 1/1]ext4: Fix WARN_ON_ONCE when marking buffer dirty
On Mon, Jul 4, 2016 at 7:59 PM, Theodore Ts'o <tytso@mit.edu> wrote:
> On Thu, Jun 30, 2016 at 02:12:30PM +0300, Pranay Kr. Srivastava wrote:
>> Signed-off-by: Pranay Kr. Srivastava <pranjas@gmail.com>
>
> The description for why the change is being made should go in the
> commit. (No need to put the description in a separate cover letter.)
> I ended up rewriting the commit description as follows, to make it
> much more understandable:
>
> ext4: Fix WARN_ON_ONCE in ext4_commit_super()
>
> If there are racing calls to ext4_commit_super() it's possible for
> another writeback of the superblock to result in the buffer being
> marked with an error after we check if the buffer is marked as
> having a write error and the buffer up-to-date flag is set again.
> If that happens mark_buffer_dirty() can end up throwing a
> WARN_ON_ONCE.
>
> Fix this by moving this check to write before we call
> write_buffer_dirty(), and keeping the buffer locked during this
> whole sequence.
>
> Signed-off-by: Pranay Kr. Srivastava <pranjas@gmail.com>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
>
> Note that the one-line summary needs to carry as much information as
> possible so someone who is scanning the commits using git log
> --oneline has a chance of understanding it. This means the high-level
> *why* of the commit, not a summary of what the changes in the C code.
> Also note the increased context of when the misbehaviour could occur
> in the commit description, which was missing in the cover letter.
>
> When I'm processing patches, if I'm in a hurry, patches that require
> extra work or which aren't Obviously Right, sometimes get deferred by
> a few days. This patch fell in that category.
>
> Adding to the commit descrtipion additional context and/or
> instructions for how to reproduce the problem you are trying to
> remediate will often make life much easier for me, and accelerate how
> quickly I'll get to your patch.
>
> Cheers,
>
> - Ted

Thank you Theodore Sir. Points duly noted, I'll take care from now on
while sending
patches.


--
---P.K.S

\
 
 \ /
  Last update: 2016-07-05 06:01    [W:0.041 / U:19.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site