From: Sagi Grimberg <sagi@grimberg.me>
Date: Wed, 2 Oct 2019 10:52:25 -0700
Subject: [PATCH] nvme: fix possible deadlock when nvme_update_formats fails
Git-commit: 6abff1b9f7b8884a46b7bd80b49e7af0b5625aeb
Patch-mainline: v5.4-rc4
References: bsc#1169045

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>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/host/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index fd7dea36c3b6..ef1d8f81f69e 100644
--- 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)
-- 
2.16.4