nvme: fix possible deadlock when nvme_update_formats fails

nvme_update_formats may fail to revalidate the namespace and
attempt to remove the namespace. This may lead to a deadlock
as nvme_ns_remove will attempt to acquire the subsystem lock
which is already acquired by the passthru command with effects.

Move the invalid namepsace removal to after the passthru command
releases the subsystem lock.

Reported-by: Judy Brock <judy.brock@samsung.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index fd7dea3..ef1d8f8 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1306,8 +1306,6 @@ static void nvme_update_formats(struct nvme_ctrl *ctrl)
                if (ns->disk && nvme_revalidate_disk(ns->disk))
                        nvme_set_queue_dying(ns);
        up_read(&ctrl->namespaces_rwsem);
-
-       nvme_remove_invalid_namespaces(ctrl, NVME_NSID_ALL);
 }
 
 static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
@@ -1323,6 +1321,7 @@ static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
                nvme_unfreeze(ctrl);
                nvme_mpath_unfreeze(ctrl->subsys);
                mutex_unlock(&ctrl->subsys->lock);
+               nvme_remove_invalid_namespaces(ctrl, NVME_NSID_ALL);
                mutex_unlock(&ctrl->scan_lock);
        }
        if (effects & NVME_CMD_EFFECTS_CCC)