On Mon, Jan 12 2015 at 2:11pm -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > On Mon, Jan 12 2015 at 1:35pm -0500, > Keith Busch <keith.busch@xxxxxxxxx> wrote: > > > On Mon, 12 Jan 2015, Keith Busch wrote: > > >Oh, let's look at "__blk_rq_prep_clone". dm calls that after > > >blk_get_request() for the blk-mq based multipath types and overrides the > > >destinations cmd_flags with the source's even though the source was not > > >allocated from a blk-mq based queue, much less a shared tag. > > > > Untested patch. This will also preserve the failfast cmd_flag dm-mpath > > set after allocating. > > Ah, good point. The failfast flag would get cleared with the patch I > just proposed (unless REQ_FAILFAST_TRANSPORT was added to > REQ_PRESERVE_CLONE_MASK). > > Anyway, I'm happy to see this implemented however you guys think is > best. I think I like Keith's patch better than mine. FYI, I staged Keith's patch here: https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-for-3.20-blk-mq&id=7004ddf2462df38c6e3232ac020ed6ff655cc07e Bart, this is the tip of the linux-dm.git "dm-for-3.20-blk-mq" branch. Please test, it should hopefully take care of the stall you've been seeing. Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
