nvme-multipath: revalidate paths during rescan

When triggering a rescan due to a namespace resize we will be
receiving AENs on every controller, triggering a rescan of all
attached namespaces. If multipath is active only the current path and
the ns_head disk will be updated, the other paths will still refer to
the old size until AENs for the remaining controllers are received.

If I/O comes in before that it might be routed to one of the old
paths, triggering an I/O failure with 'access beyond end of device'.
With this patch the old paths are skipped from multipath path
selection until the controller serving these paths has been rescanned.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[dwagner: - introduce NVME_NS_READY flag instead of NVME_NS_INVALIDATE
          - use 'revalidate' instead of 'invalidate' which
	    follows the zoned device code path.
	  - clear NVME_NS_READY before clearing current_path]
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 8679a108f571ee8170219d906535b244f145896e..f5502ee45b96adce332abdd641126ba97c1d9473 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1874,6 +1874,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
                        goto out_unfreeze;
        }
 
+       set_bit(NVME_NS_READY, &ns->flags);
        blk_mq_unfreeze_queue(ns->disk->queue);
 
        if (blk_queue_is_zoned(ns->queue)) {
@@ -1885,6 +1886,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
        if (nvme_ns_head_multipath(ns->head)) {
                blk_mq_freeze_queue(ns->head->disk->queue);
                nvme_update_disk_info(ns->head->disk, ns, id);
+               nvme_mpath_revalidate_paths(ns);
                blk_stack_limits(&ns->head->disk->queue->limits,
                                 &ns->queue->limits, 0);
                disk_update_readahead(ns->head->disk);
@@ -3795,6 +3797,7 @@ static void nvme_ns_remove(struct nvme_ns *ns)
        if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))
                return;
 
+       clear_bit(NVME_NS_READY, &ns->flags);
        set_capacity(ns->disk, 0);
        nvme_fault_inject_fini(&ns->fault_inject);
 

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index d9a82adb856f911b66f98c0f25841a529771aea2..5d7bc58a27bd984dc7f19341dcdcf1a3d3af658d 100644 (file)
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -147,6 +147,21 @@ void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
        mutex_unlock(&ctrl->scan_lock);
 }
 
+void nvme_mpath_revalidate_paths(struct nvme_ns *ns)
+{
+       struct nvme_ns_head *head = ns->head;
+       sector_t capacity = get_capacity(head->disk);
+       int node;
+
+       list_for_each_entry_rcu(ns, &head->list, siblings) {
+               if (capacity != get_capacity(ns->disk))
+                       clear_bit(NVME_NS_READY, &ns->flags);
+       }
+
+       for_each_node(node)
+               rcu_assign_pointer(head->current_path[node], NULL);
+}
+
 static bool nvme_path_is_disabled(struct nvme_ns *ns)
 {
        /*
@@ -158,7 +173,7 @@ static bool nvme_path_is_disabled(struct nvme_ns *ns)
            ns->ctrl->state != NVME_CTRL_DELETING)
                return true;
        if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
-           test_bit(NVME_NS_REMOVING, &ns->flags))
+           !test_bit(NVME_NS_READY, &ns->flags))
                return true;
        return false;
 }

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index a2e1f298b217c4a1dae5cfe7fe890414e6c8422e..8fd30ef19757696577a3e2aff1496aa36df54cdc 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -456,6 +456,7 @@ struct nvme_ns {
 #define NVME_NS_DEAD           1
 #define NVME_NS_ANA_PENDING    2
 #define NVME_NS_FORCE_RO       3
+#define NVME_NS_READY          4
 
        struct cdev             cdev;
        struct device           cdev_device;
@@ -748,6 +749,7 @@ void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl);
 void nvme_mpath_uninit(struct nvme_ctrl *ctrl);
 void nvme_mpath_stop(struct nvme_ctrl *ctrl);
 bool nvme_mpath_clear_current_path(struct nvme_ns *ns);
+void nvme_mpath_revalidate_paths(struct nvme_ns *ns);
 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl);
 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head);
 
@@ -795,6 +797,9 @@ static inline bool nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
        return false;
 }
+static inline void nvme_mpath_revalidate_paths(struct nvme_ns *ns)
+{
+}
 static inline void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
 {
 }