Merge tag 'samsung-soc-5.10' of https://git.kernel.org/pub/scm/linux/kernel/git/krzk...

[linux-2.6-microblaze.git] / drivers / nvme / host / multipath.c

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 3ded54d..d4ba736 100644 (file)
--- 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)
@@ -233,7 +212,7 @@ 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))
@@ -252,18 +231,22 @@ 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;
        }
 
-       /* 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;
-       }
-       if (!fallback)
+           (old->ana_state == NVME_ANA_OPTIMIZED ||
+            (!found && old->ana_state == NVME_ANA_NONOPTIMIZED)))
+               return old;
+
+       if (!found)
                return NULL;
-       found = fallback;
 out:
        rcu_assign_pointer(head->current_path[node], found);
        return found;