[dm-devel] livelock on MD RAID5

[Mikulas Patocka]

Hi Neil

I saw your patch "md/raid5: avoid livelock caused by non-aligned writes". 
That patch is only for RAID 6, but we are seeing similar livelock on RAID5 
(mdX_raid5 is constantly looping in 
raid5d/handle_active_stripes/handle_stripe/ops_run_io and some submitted 
bios get stuck). The livelock happens when we issue I/O and simulate disk 
failure.

Do you think that the same issue could happen on RAID5 too?

Do you think that the patch "md/raid5: fetch_block must fetch all the 
blocks handle_stripe_dirtying wants." could fix it?

Mikulas