[PATCH 1/2] nvmet-tcp: fix lockdep complaint on nvmet_tcp_wq flush during queue teardown

[Christoph Hellwig]

From: Sagi Grimberg <sagi at grimberg.me>

We probably need nvmet_tcp_wq to have MEM_RECLAIM as we are
sending/receiving for the socket from works on this workqueue.
Also this eliminates lockdep complaints:
--
[ 6174.010200] workqueue: WQ_MEM_RECLAIM
nvmet-wq:nvmet_tcp_release_queue_work [nvmet_tcp] is flushing
!WQ_MEM_RECLAIM nvmet_tcp_wq:nvmet_tcp_io_work [nvmet_tcp]
[ 6174.010216] WARNING: CPU: 20 PID: 14456 at kernel/workqueue.c:2628
check_flush_dependency+0x110/0x14c

Reported-by: Yi Zhang <yi.zhang at redhat.com>
Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/nvme/target/tcp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 0a9542599ad1c..dc3b4dc8fe08b 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1839,7 +1839,8 @@ static int __init nvmet_tcp_init(void)
 {
 	int ret;
 
-	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
+	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq",
+				WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
 	if (!nvmet_tcp_wq)
 		return -ENOMEM;
 
-- 
2.30.2