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From:   Daniel Wagner <dwagner@suse.de>
To:     linux-nvme@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, Keith Busch <kbusch@kernel.org>,
        Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        Daniel Wagner <dwagner@suse.de>, Hannes Reinecke <hare@suse.de>
Subject: [PATCH v2] nvme-multipath: Early exit if no path is available
Date:   Wed, 27 Jan 2021 11:30:33 +0100
Message-Id: <20210127103033.15318-1-dwagner@suse.de>
MIME-Version: 1.0
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Precedence: bulk

nvme_round_robin_path() should test if the return ns pointer is
valid. nvme_next_ns() will return a NULL pointer if there is no path
left.

Fixes: 75c10e732724 ("nvme-multipath: round-robin I/O policy")
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
v2:
  - moved NULL test into the if conditional statement
  - added Fixes tag

 drivers/nvme/host/multipath.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 9ac762b28811..282b7a4ea9a9 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -221,7 +221,7 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
 	}
 
 	for (ns = nvme_next_ns(head, old);
-	     ns != old;
+	     ns && ns != old;
 	     ns = nvme_next_ns(head, ns)) {
 		if (nvme_path_is_disabled(ns))
 			continue;
-- 
2.29.2