[PATCH 2/2] nvmet-tcp: avoid circular locking dependency on install_queue()
Hannes Reinecke
hare at suse.de
Wed Nov 1 03:32:28 PDT 2023
nvmet_tcp_install_queue() is driven from the ->io_work workqueue
function, but will call flush_workqueue() which might trigger
->release_work() which in itself calls flush_work on ->io_work.
To avoid that check for pending queue in disconnecting status,
and return 'controller busy' until all disconnects are completed.
Signed-off-by: Hannes Reinecke <hare at suse.de>
---
drivers/nvme/target/tcp.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index b3c1cc6690f6..ecc9ccfac823 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -2121,8 +2121,18 @@ static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
container_of(sq, struct nvmet_tcp_queue, nvme_sq);
if (sq->qid == 0) {
- /* Let inflight controller teardown complete */
- flush_workqueue(nvmet_wq);
+ struct nvmet_tcp_queue *q;
+ int pending = 0;
+
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_for_each_entry(q, &nvmet_tcp_queue_list, queue_list) {
+ if (q->state == NVMET_TCP_Q_DISCONNECTING)
+ pending++;
+ }
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+ /* Retry for pending controller teardown */
+ if (pending)
+ return NVME_SC_CONNECT_CTRL_BUSY;
}
queue->nr_cmds = sq->size * 2;
--
2.35.3
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