Re: DM Regression in 4.16-rc1 - read() returns data when it shouldn't

From: NeilBrown
Date: Mon Feb 26 2018 - 06:01:30 EST


On Mon, Feb 26 2018, Thorsten Leemhuis wrote:

> Hi Mike! On 19.02.2018 18:15, Mike Snitzer wrote:
>> On Mon, Feb 19 2018 at 8:44am -0500,
>> Thorsten Leemhuis <regressions@xxxxxxxxxxxxx> wrote:
>>
>>> JFYI: This issues is tracked in the regression reports for Linux 4.16
>>> (http://bit.ly/lnxregrep416 ) with this id:
>>> Linux-Regression-ID: lr#9e195f
>>> Please include this line in the comment section of patches that are
>> [â]
>> The fix was already merged by Linus on Friday, see:
>> git.kernel.org/linus/8dd601fa8317243be887458c49f6c29c2f3d719f
>
> Ohh, thx for the pointer. Could you please next time add a tag like
>
> Fixes: 18a25da84354 ("dm: ensure bio submission follows a depth-first
> tree walk")

The thing is... it didn't fix that commit. That commit was fine.
If fixed something else much further back, which that commit just made
more problematic.
That is why I added the Cc: stable with the earliest version that needed
fixing.

Unfortunately, reality isn't always neat and tidy :-( when it is, I do
use Fixes:

Thanks,
NeilBrown

>
> to the commit? For details see
> Documnetation/process/submitting-patches.rst section 2 and 13:
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html
>
> That would have saved both of us this conversation. In addition I head
> that at least one big Linux distributor is using those tags when
> backporting changes to make sure all relevant fixes for a particular
> backported commit get backported as well.
>
>> But moving forward I have no interest in sprinkling external metadata
>> references in Linux commit headers.
>>
>> Seems more like you're engineering something that gives you, and
>> possibly a select few others, meaning but that is make work for all
>> Linux maintainers.
>
> I just asked you to help me make regression tracking work a little bit
> easier. I'm neither planing to enforce this nor in a position to do so,
> thus feel free to not do what I asked for; that's totally fine for me.
> Especially as those tags are only a interim solution afaics (one that I
> don't like to much myself; but they sometimes help connecting the
> various dots in the phase where the commit that introduced a regression
> is not yet known).
>
> Ciao, Thorsten

Attachment: signature.asc
Description: PGP signature