nvme-tcp: fix potential unbalanced freeze & unfreeze

Move start_freeze into nvme_tcp_configure_io_queues(), and there is
at least two benefits:

1) fix unbalanced freeze and unfreeze, since re-connection work may
fail or be broken by removal

2) IO during error recovery can be failfast quickly because nvme fabrics
unquiesces queues after teardown.

One side-effect is that !mpath request may timeout during connecting
because of queue topo change, but that looks not one big deal:

1) same problem exists with current code base

2) compared with !mpath, mpath use case is dominant

Fixes: 2875b0aecabe ("nvme-tcp: fix controller reset hang during traffic")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 3e7dd6f91832b0e25770604559e9cb907777dde6..fb24cd8ac46c869b11e201259df7896fefcb1e5c 100644 (file)
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1868,6 +1868,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
                goto out_cleanup_connect_q;
 
        if (!new) {
+               nvme_start_freeze(ctrl);
                nvme_unquiesce_io_queues(ctrl);
                if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) {
                        /*
@@ -1876,6 +1877,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
                         * to be safe.
                         */
                        ret = -ENODEV;
+                       nvme_unfreeze(ctrl);
                        goto out_wait_freeze_timed_out;
                }
                blk_mq_update_nr_hw_queues(ctrl->tagset,
@@ -1980,7 +1982,6 @@ static void nvme_tcp_teardown_io_queues(struct nvme_ctrl *ctrl,
        if (ctrl->queue_count <= 1)
                return;
        nvme_quiesce_admin_queue(ctrl);
-       nvme_start_freeze(ctrl);
        nvme_quiesce_io_queues(ctrl);
        nvme_sync_io_queues(ctrl);
        nvme_tcp_stop_io_queues(ctrl);