nvmet: fix nvme status code when namespace is disabled

If the user disabled a nvmet namespace, it is removed from the subsystem
namespaces list. When nvmet processes a command directed to an nsid that
was disabled, it cannot differentiate between a nsid that is disabled
vs. a non-existent namespace, and resorts to return NVME_SC_INVALID_NS
with the dnr bit set.

This translates to a non-retryable status for the host, which translates
to a user error. We should expect disabled namespaces to not cause an
I/O error in a multipath environment.

Address this by searching a configfs item for the namespace nvmet failed
to find, and if we found one, conclude that the namespace is disabled
(perhaps temporarily). Return NVME_SC_INTERNAL_PATH_ERROR in this case
and keep DNR bit cleared.

Reported-by: Jirong Feng <jirong.feng@easystack.cn>
Tested-by: Jirong Feng <jirong.feng@easystack.cn>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index a232533..89a0011 100644 (file)
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -754,6 +754,19 @@ static struct configfs_attribute *nvmet_ns_attrs[] = {
        NULL,
 };
 
+bool nvmet_subsys_nsid_exists(struct nvmet_subsys *subsys, u32 nsid)
+{
+       struct config_item *ns_item;
+       char name[4] = {};
+
+       if (sprintf(name, "%u", nsid) <= 0)
+               return false;
+       mutex_lock(&subsys->namespaces_group.cg_subsys->su_mutex);
+       ns_item = config_group_find_item(&subsys->namespaces_group, name);
+       mutex_unlock(&subsys->namespaces_group.cg_subsys->su_mutex);
+       return ns_item != NULL;
+}
+
 static void nvmet_ns_release(struct config_item *item)
 {
        struct nvmet_ns *ns = to_nvmet_ns(item);

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 8860a3e..e06013c 100644 (file)
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -437,10 +437,13 @@ void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
 u16 nvmet_req_find_ns(struct nvmet_req *req)
 {
        u32 nsid = le32_to_cpu(req->cmd->common.nsid);
+       struct nvmet_subsys *subsys = nvmet_req_subsys(req);
 
-       req->ns = xa_load(&nvmet_req_subsys(req)->namespaces, nsid);
+       req->ns = xa_load(&subsys->namespaces, nsid);
        if (unlikely(!req->ns)) {
                req->error_loc = offsetof(struct nvme_common_command, nsid);
+               if (nvmet_subsys_nsid_exists(subsys, nsid))
+                       return NVME_SC_INTERNAL_PATH_ERROR;
                return NVME_SC_INVALID_NS | NVME_SC_DNR;
        }
 

diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index f460728..c1306de 100644 (file)
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -543,6 +543,7 @@ void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
                struct nvmet_host *host);
 void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
                u8 event_info, u8 log_page);
+bool nvmet_subsys_nsid_exists(struct nvmet_subsys *subsys, u32 nsid);
 
 #define NVMET_MIN_QUEUE_SIZE   16
 #define NVMET_MAX_QUEUE_SIZE   1024