From: Keith Busch kbusch@kernel.org
[ Upstream commit a0fdd1418007f83565d3f2e04b47923ba93a9b8c ]
A possible race condition exists where the request to send data is enqueued from nvme_tcp_handle_r2t()'s will not be observed by nvme_tcp_send_all() if it happens to be running. The driver relies on io_work to send the enqueued request when it is runs again, but the concurrently running nvme_tcp_send_all() may not have released the send_mutex at that time. If no future commands are enqueued to re-kick the io_work, the request will timeout in the SEND_H2C state, resulting in a timeout error like:
nvme nvme0: queue 1: timeout request 0x3 type 6
Ensure the io_work continues to run as long as the req_list is not empty.
Fixes: db5ad6b7f8cdd ("nvme-tcp: try to send request in queue_rq context") Signed-off-by: Keith Busch kbusch@kernel.org Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 4cf81f3841ae..7346a05d395b 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1140,7 +1140,8 @@ static void nvme_tcp_io_work(struct work_struct *w) pending = true; else if (unlikely(result < 0)) break; - } + } else + pending = !llist_empty(&queue->req_list);
result = nvme_tcp_try_recv(queue); if (result > 0)