On Tue, Dec 19 2017 at 4:05pm -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > These patches enable DM multipath to work well on NVMe over Fabrics > devices. Currently that implies CONFIG_NVME_MULTIPATH is _not_ set. > > But follow-on work will be to make it so that native NVMe multipath > and DM multipath can be made to co-exist (e.g. blacklisting certain > NVMe devices from being consumed by native NVMe multipath?) > > Patch 1 updates block core to formalize a recent construct that > Christoph embeedded into NVMe core (and native NVMe multipath): > callback into a bio-based driver from the blk-mq driver's .complete > hook to blk_steal_bios() a request's bios. > > Patch 2 switches NVMe over to using the block infrastructure > established by Patch 1. > > Patch 3 moves the nvme_req_needs_failover() from NVMe multipath to > core. Which allow sstacked devices (like DM multipath) to make use of > NVMe's enhanced error handling. > > Patch 4 updates DM multipath to also make use of the block > infrastructure established by Patch 1. > > Patch 5 can be largely ignored.. but it illustrates that Patch 1 - 4 > enable DM multipath to avoid extra DM endio callbacks. > > These patches have been developed ontop of numerous DM changes I've > staged for 4.16, see: > https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-4.16 > (which happens to include these 5 patches at the end, purely for > interim linux-next coverage purposes as these changes land in the > appropriate maintainer tree). > > I've updated the "mptest" DM multipath testsuite to provide NVMe test > coverage (using NVMe fcloop), see: https://github.com/snitm/mptest > > The tree I've been testing includes all of 'dm-4.16' and all but one > of the commits from 'nvme-4.16', see: > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=dm-4.16_nvme-4.16 > (I've let James Smart know that commit a0b69cc8 causes "nvme connect" > to not work on my fcloop testbed). > > Jens, provided review is favorable, I'd very much appreciate it you'd > pick up patches 1 - 3 for 4.16. BTW, Christoph if you're open to picking up patches 1 - 3 into 'nvme-4.16' that works too. I just figured since there is a block core dependency Jens would want to take them direct. Thanks, Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
