On 08/03/2016 06:55 PM, Bart Van Assche wrote: > On 08/02/2016 05:40 PM, Mike Snitzer wrote: >> But I asked you to run the v4.7 kernel patches I >> pointed to _without_ any of your debug patches. > > I need several patches to fix bugs that are not related to the device > mapper, e.g. "sched: Avoid that __wait_on_bit_lock() hangs" > (https://lkml.org/lkml/2016/8/3/289). > Hmm. Can you test with this patch? diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 7790a70..9daed03 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -439,8 +439,7 @@ static int must_push_back(struct multipath *m) { return (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || ((test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) != - test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) && - dm_noflush_suspending(m->ti))); + test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags))); } /* Reasoning: The original check for dm_noflush_suspending() was for bio-based drivers, which needed to queue I/O within the device-mapper core. So during suspend this I/O would keep a reference to the device-mapper core and the table couldn't be swapped. For request-based multipathing, however, the I/O is _never_ held within the device-mapper core but rather pushed back to the request queue. IE even for pushback the I/O will never hold a reference to the device-mapper core, and the tables can be swapped irrespective of the 'dm_noflush_suspend()' setting. Or that's the idea, at least :-) Yes Mike, I know, it's not going to work with bio-based multipathing. But this is just for figuring out where the real issue is. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
