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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Sagi Grimberg <sagi@grimberg.me>,
        Christoph Hellwig <hch@lst.de>
Subject: [PATCH 5.11 043/120] nvme-tcp: fix possible hang when failing to set io queues
Date:   Mon, 22 Mar 2021 13:27:06 +0100
Message-Id: <20210322121931.096604977@linuxfoundation.org>
In-Reply-To: <20210322121929.669628946@linuxfoundation.org>
References: <20210322121929.669628946@linuxfoundation.org>
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From: Sagi Grimberg <sagi@grimberg.me>

commit 72f572428b83d0bc7028e7c4326d1a5f45205e44 upstream.

We only setup io queues for nvme controllers, and it makes absolutely no
sense to allow a controller (re)connect without any I/O queues.  If we
happen to fail setting the queue count for any reason, we should not
allow this to be a successful reconnect as I/O has no chance in going
through. Instead just fail and schedule another reconnect.

Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvme/host/tcp.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1748,8 +1748,11 @@ static int nvme_tcp_alloc_io_queues(stru
 		return ret;
 
 	ctrl->queue_count = nr_io_queues + 1;
-	if (ctrl->queue_count < 2)
-		return 0;
+	if (ctrl->queue_count < 2) {
+		dev_err(ctrl->device,
+			"unable to set any I/O queues\n");
+		return -ENOMEM;
+	}
 
 	dev_info(ctrl->device,
 		"creating %d I/O queues.\n", nr_io_queues);