On 06.03.2017 21:18, Jens Axboe wrote: > On 03/05/2017 09:40 PM, NeilBrown wrote: >> On Fri, Mar 03 2017, Jack Wang wrote: >>> >>> Thanks Neil for pushing the fix. >>> >>> We can optimize generic_make_request a little bit: >>> - assign bio_list struct hold directly instead init and merge >>> - remove duplicate code >>> >>> I think better to squash into your fix. >> >> Hi Jack, >> I don't object to your changes, but I'd like to see a response from >> Jens first. >> My preference would be to get the original patch in, then other changes >> that build on it, such as this one, can be added. Until the core >> changes lands, any other work is pointless. >> >> Of course if Jens wants a this merged before he'll apply it, I'll >> happily do that. > > I like the change, and thanks for tackling this. It's been a pending > issue for way too long. I do think we should squash Jack's patch > into the original, as it does clean up the code nicely. > > Do we have a proper test case for this, so we can verify that it > does indeed also work in practice? > Hi Jens,
I can trigger deadlock with in RAID1 with test below: I create one md with one local loop device and one remote scsi exported by SRP. running fio with mix rw on top of md, force_close session on storage side. mdx_raid1 is wait on free_array in D state, and a lot of fio also in D state in wait_barrier. With the patch from Neil above, I can no longer trigger it anymore. The discussion was in link below: http://www.spinics.net/lists/raid/msg54680.html Thanks, Jack Wang
