Re: [GIT PULL] md-next 20220921

[Song Liu <songliubraving@fb.com>]

Hi Logan, 

> On Sep 21, 2022, at 4:44 PM, Logan Gunthorpe <logang@deltatee.com> wrote:
> 
> On 2022-09-21 16:37, Logan Gunthorpe wrote:
>> 
>> 
>> On 2022-09-21 15:33, Song Liu wrote:
>>> Hi Jens, 
>>> 
>>> Please consider pulling the following changes for md-next on top of your
>>> for-6.1/block branch (for-6.1/drivers branch doesn't exist yet). 
>>> 
>>> The major changes are:
>>> 
>>> 1. Various raid5 fix and clean up, by Logan Gunthorpe and David Sloan.
>>> 2. Raid10 performance optimization, by Yu Kuai. 
>>> 3. Generate CHANGE uevents for md device, by Mateusz Grzonka. 
>> 
>> I may have hit a bug with my tests on the latest md-next branch. Still
>> trying to hit it again. The last tests I ran for several days with some
>> patches on the previous md-next branch, but I didn't have Mateusz's
>> changes, and it also looks like the branch was rebased today so it could
>> be caused by either of those things. I'll let you know when I know more.
> 
> Yes, ok, I've found two separate issues and both are fixed by reverting
> 
>   21023a82bff7 ("md: generate CHANGE uevents for md device")
> 
> I suggest we drop that patch for this cycle so we can sort them out.
> 
> The issues are:
> 
> 1) The concrete issue comes when running mdadm test 01r1fail. I get the
> kernel bugs at the end of this email. It seems we cannot call
> kobject_uevent() in at least one of the contexts that md_new_event() is
> called in because it sleeps in a critical section.
> 
> 2) With our custom test suite that creates and destroys arrays, adds and
> removes disks, and runs data through them repeatedly, I randomly start
> seeing these warnings:
> 
>   mdadm: Fail to create md0 when using
> /sys/module/md_mod/parameters/new_array, fallback to creation via node
> 
> And then very occasionally get that warning paired with this error:
> 
>   mdadm: unexpected failure opening /dev/md0
> 
> Which stops the test because it fails to create an array. I also see a
> lot of the same bugs as below so it may be related.

Thanks for testing and debugging these issues. I also see issue 1). 

Jens, please ignore this pull request. I will send v2 later. 

Song