lkml.org 
[lkml]   [2023]   [Oct]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: block: Don't invalidate pagecache for invalid falloc modes
From
On 10/11/23 2:50 PM, Mike Snitzer wrote:
> On Wed, Oct 11 2023 at 4:20P -0400,
> Jens Axboe <axboe@kernel.dk> wrote:
>
>> On 10/11/23 2:12 PM, Sarthak Kukreti wrote:
>>> Only call truncate_bdev_range() if the fallocate mode is
>>> supported. This fixes a bug where data in the pagecache
>>> could be invalidated if the fallocate() was called on the
>>> block device with an invalid mode.
>>
>> Fix looks fine, but would be nicer if we didn't have to duplicate the
>> truncate_bdev_range() in each switch clause. Can we check this upfront
>> instead?
>
> No, if you look at the function (rather than just the patch in
> isolation) we need to make the call for each case rather than collapse
> to a single call at the front (that's the reason for this fix, because
> otherwise the default: error case will invalidate the page cache too).

Yes that part is clear, but it might look cleaner to check a valid mask
first rather than have 3 duplicate calls.

> Just so you're aware, I also had this feedback that shaped the patch a
> bit back in April:
> https://listman.redhat.com/archives/dm-devel/2023-April/053986.html
>
>> Also, please wrap commit messages at 72-74 chars.
>
> Not seeing where the header should be wrapped. You referring to the
> Fixes: line? I've never seen those wrapped.

I'm referring to the commit message itself.

--
Jens Axboe

\
 
 \ /
  Last update: 2023-10-11 22:54    [W:0.048 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site