[PATCH rfc 1/2] nvme: don't remove namespace if revalidate failed because of controller reset

From: sagi@grimberg.me (Sagi Grimberg)
Subject: [PATCH rfc 1/2] nvme: don't remove namespace if revalidate failed because of controller reset
Date: Mon, 29 Jul 2019 16:32:00 -0700	[thread overview]
Message-ID: <20190729233201.27993-2-sagi@grimberg.me> (raw)
In-Reply-To: <20190729233201.27993-1-sagi@grimberg.me>

If a controller reset is racing with a namespace revalidation, the
revalidation I/O will surely fail, but we should not remove the
namespace as we will execute the I/O when the controller is LIVE again.
Specifically check if the controller is LIVE because as
RESETTING/CONNECTING are transient and DELETING/DEAD will eventually
remove the namespace in the removal code path.

This fixes sporious I/O errors in path failover coditions where the
controller reset is racing with the namespace scan work.

Reported-by: Hannes Reinecke  <hare at suse.de>
Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
---
 drivers/nvme/host/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index fa31da0762b9..5f6970e7ba73 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3428,7 +3428,8 @@ static void nvme_validate_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 
 	ns = nvme_find_get_ns(ctrl, nsid);
 	if (ns) {
-		if (ns->disk && revalidate_disk(ns->disk))
+		if (ns->disk && revalidate_disk(ns->disk) &&
+		    ctrl->state != NVME_CTRL_LIVE)
 			nvme_ns_remove(ns);
 		nvme_put_ns(ns);
 	} else
-- 
2.17.1
