Commit 93eb0381 authored Aug 06, 2020 by Martin Wilck Committed by Jens Axboe Aug 21, 2020

nvme: multipath: round-robin: fix single non-optimized path case



If there's only one usable, non-optimized path, nvme_round_robin_path()
returns NULL, which is wrong. Fix it by falling back to "old", like in
the single optimized path case. Also, if the active path isn't changed,
there's no need to re-assign the pointer.

Fixes: 3f6e3246 ("nvme-multipath: fix logic for non-optimized paths")
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin George <marting@netapp.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent f34448cd

drivers/nvme/host/multipath.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -255,12 +255,17 @@ static struct nvme_ns nvme_round_robin_path(struct nvme_ns_head head,
		fallback = ns;
		}

		/* No optimized path found, re-check the current path */
		/*
		* The loop above skips the current path for round-robin semantics.
		* Fall back to the current path if either:
		* - no other optimized path found and current is optimized,
		* - no other usable path found and current is usable.
		*/
		if (!nvme_path_is_disabled(old) &&
		old->ana_state == NVME_ANA_OPTIMIZED) {
		found = old;
		goto out;
		}
		(old->ana_state == NVME_ANA_OPTIMIZED \|\|
		(!fallback && old->ana_state == NVME_ANA_NONOPTIMIZED)))
		return old;

		if (!fallback)
		return NULL;
		found = fallback;

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