From 93eb0381e13d249a18ed4aae203291ff977e7ffb Mon Sep 17 00:00:00 2001 From: Martin Wilck Date: Thu, 6 Aug 2020 15:19:31 +0200 Subject: 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: 3f6e3246db0e ("nvme-multipath: fix logic for non-optimized paths") Signed-off-by: Martin Wilck Signed-off-by: Martin George Reviewed-by: Keith Busch Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe --- drivers/nvme/host/multipath.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'drivers/nvme/host/multipath.c') diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 3ded54d2c9c6..a64dfff0d0ce 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -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; -- cgit From e398863b75af24103cee69cc8ee8bf4bc9c8913e Mon Sep 17 00:00:00 2001 From: Martin Wilck Date: Thu, 6 Aug 2020 15:19:32 +0200 Subject: nvme: multipath: round-robin: eliminate "fallback" variable If we find an optimized path, we quit the loop immediately. Thus we can use just one variable for the next path, slighly simplifying the code. Signed-off-by: Martin Wilck Reviewed-by: Keith Busch Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe --- drivers/nvme/host/multipath.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'drivers/nvme/host/multipath.c') diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index a64dfff0d0ce..760f625cefc8 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -233,7 +233,7 @@ static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head, static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head, int node, struct nvme_ns *old) { - struct nvme_ns *ns, *found, *fallback = NULL; + struct nvme_ns *ns, *found = NULL; if (list_is_singular(&head->list)) { if (nvme_path_is_disabled(old)) @@ -252,7 +252,7 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head, goto out; } if (ns->ana_state == NVME_ANA_NONOPTIMIZED) - fallback = ns; + found = ns; } /* @@ -263,12 +263,11 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head, */ if (!nvme_path_is_disabled(old) && (old->ana_state == NVME_ANA_OPTIMIZED || - (!fallback && old->ana_state == NVME_ANA_NONOPTIMIZED))) + (!found && old->ana_state == NVME_ANA_NONOPTIMIZED))) return old; - if (!fallback) + if (!found) return NULL; - found = fallback; out: rcu_assign_pointer(head->current_path[node], found); return found; -- cgit From 5ddaabe8ed713f148e3d67e99b86d99427aceb5c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 18 Aug 2020 09:11:30 +0200 Subject: nvme: refactor command completion Lift all the code to decide the dispostition of a completed command from nvme_complete_rq and nvme_failover_req into a new helper, which returns an emum of the potential actions. nvme_complete_rq then just switches on those and calls the proper helper for the action. Signed-off-by: Christoph Hellwig Reviewed-by: Mike Snitzer Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe --- drivers/nvme/host/multipath.c | 47 ++++++++++++------------------------------- 1 file changed, 13 insertions(+), 34 deletions(-) (limited to 'drivers/nvme/host/multipath.c') diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 760f625cefc8..d4ba736c6c89 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -65,51 +65,30 @@ void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns, } } -bool nvme_failover_req(struct request *req) +void nvme_failover_req(struct request *req) { struct nvme_ns *ns = req->q->queuedata; - u16 status = nvme_req(req)->status; + u16 status = nvme_req(req)->status & 0x7ff; unsigned long flags; - switch (status & 0x7ff) { - case NVME_SC_ANA_TRANSITION: - case NVME_SC_ANA_INACCESSIBLE: - case NVME_SC_ANA_PERSISTENT_LOSS: - /* - * If we got back an ANA error we know the controller is alive, - * but not ready to serve this namespaces. The spec suggests - * we should update our general state here, but due to the fact - * that the admin and I/O queues are not serialized that is - * fundamentally racy. So instead just clear the current path, - * mark the the path as pending and kick of a re-read of the ANA - * log page ASAP. - */ - nvme_mpath_clear_current_path(ns); - if (ns->ctrl->ana_log_buf) { - set_bit(NVME_NS_ANA_PENDING, &ns->flags); - queue_work(nvme_wq, &ns->ctrl->ana_work); - } - break; - case NVME_SC_HOST_PATH_ERROR: - case NVME_SC_HOST_ABORTED_CMD: - /* - * Temporary transport disruption in talking to the controller. - * Try to send on a new path. - */ - nvme_mpath_clear_current_path(ns); - break; - default: - /* This was a non-ANA error so follow the normal error path. */ - return false; + nvme_mpath_clear_current_path(ns); + + /* + * If we got back an ANA error, we know the controller is alive but not + * ready to serve this namespace. Kick of a re-read of the ANA + * information page, and just try any other available path for now. + */ + if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) { + set_bit(NVME_NS_ANA_PENDING, &ns->flags); + queue_work(nvme_wq, &ns->ctrl->ana_work); } spin_lock_irqsave(&ns->head->requeue_lock, flags); blk_steal_bios(&ns->head->requeue_list, req); spin_unlock_irqrestore(&ns->head->requeue_lock, flags); - blk_mq_end_request(req, 0); + blk_mq_end_request(req, 0); kblockd_schedule_work(&ns->head->requeue_work); - return true; } void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl) -- cgit