[PATCH] nvme-fc: clear q_live at beginning of association teardown

From: James Smart <jsmart2021@gmail.com>
To: linux-nvme@lists.infradead.org
Cc: James Smart <jsmart2021@gmail.com>, stable@vger.kernel.org
Subject: [PATCH] nvme-fc: clear q_live at beginning of association teardown
Date: Mon, 10 May 2021 21:56:35 -0700	[thread overview]
Message-ID: <20210511045635.12494-1-jsmart2021@gmail.com> (raw)

The __nvmf_check_ready() routine used to bounce all filesystem io if
the controller state isn't LIVE. However, a later patch changed the
logic so that it rejection ends up being based on the Q live check.
The fc transport has a slightly different sequence from rdma and tcp
for shutting down queues/marking them non-live. FC marks its queue
non-live after aborting all ios and waiting for their termination,
leaving a rather large window for filesystem io to continue to hit the
transport. Unfortunately this resulted in filesystem io or applications
seeing I/O errors.

Change the fc transport to mark the queues non-live at the first
sign of teardown for the association (when i/o is initially terminated).

Fixes: 73a5379937ec ("nvme-fabrics: allow to queue requests for live queues")
Cc: <stable@vger.kernel.org> # v5.8+
Signed-off-by: James Smart <jsmart2021@gmail.com>

---
stable trees for 5.8 and 5.9 will require a slightly modified patch
---
 drivers/nvme/host/fc.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index d9ab9e7871d0..256e87721a01 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2461,6 +2461,18 @@ nvme_fc_terminate_exchange(struct request *req, void *data, bool reserved)
 static void
 __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
 {
+	int q;
+
+	/*
+	 * if aborting io, the queues are no longer good, mark them
+	 * all as not live.
+	 */
+	if (ctrl->ctrl.queue_count > 1) {
+		for (q = 1; q < ctrl->ctrl.queue_count; q++)
+			clear_bit(NVME_FC_Q_LIVE, &ctrl->queues[q].flags);
+	}
+	clear_bit(NVME_FC_Q_LIVE, &ctrl->queues[0].flags);
+
 	/*
 	 * If io queues are present, stop them and terminate all outstanding
 	 * ios on them. As FC allocates FC exchange for each io, the
-- 
2.26.2

