nvme-mpath: fix last path removal during traffic

In case our last path is removed during traffic, we can end up requeueing
the bio(s) but never schedule the actual requeue work as upper layers
still have open handles on the mpath device node.

Fix this by scheduling requeue work if the namespace being removed is
the last path in the ns_head path list.

Fixes: 32acab3181c7 ("nvme: implement multipath access to nvme subsystems")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 961d6a4af19cccfd9182b65d92135f816740d022..839650e0926af1aaaf21bafbdc1baa79cf907d76 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2991,6 +2991,7 @@ static void nvme_ns_remove(struct nvme_ns *ns)
        mutex_unlock(&ns->ctrl->namespaces_mutex);
 
        synchronize_srcu(&ns->head->srcu);
+       nvme_mpath_check_last_path(ns);
        nvme_put_ns(ns);
 }
 

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index ea1aa5283e8ed9215537594a33a243d47b363e25..a00eabd0642738bbdbaf0b11d7f8e1747c996e3c 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -417,6 +417,15 @@ static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
                rcu_assign_pointer(head->current_path, NULL);
 }
 struct nvme_ns *nvme_find_path(struct nvme_ns_head *head);
+
+static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
+{
+       struct nvme_ns_head *head = ns->head;
+
+       if (head->disk && list_empty(&head->list))
+               kblockd_schedule_work(&head->requeue_work);
+}
+
 #else
 static inline void nvme_failover_req(struct request *req)
 {
@@ -448,6 +457,9 @@ static inline void nvme_mpath_remove_disk_links(struct nvme_ns *ns)
 static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
 }
+static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
+{
+}
 #endif /* CONFIG_NVME_MULTIPATH */
 
 #ifdef CONFIG_NVM