[PATCH 5.10 062/157] nvme-rdma: fix possible hang when failing to set io queues

Greg Kroah-Hartman
2021-03-22T12:45:36Z

From: Sagi Grimberg <sagi@grimberg.me>

[ Upstream commit c4c6df5fc84659690d4391d1fba155cd94185295 ]

We only setup io queues for nvme controllers, and it makes absolutely no
sense to allow a controller (re)connect without any I/O queues. If we
happen to fail setting the queue count for any reason, we should not allow
this to be a successful reconnect as I/O has no chance in going through.
Instead just fail and schedule another reconnect.

Reported-by: Chao Leng <lengchao@huawei.com>
Fixes: 711023071960 ("nvme-rdma: add a NVMe over Fabrics RDMA host driver")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chao Leng <lengchao@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/rdma.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 195703013272..8b326508a480 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -736,8 +736,11 @@ static int nvme_rdma_alloc_io_queues(struct nvme_rdma_ctrl *ctrl)
return ret;

ctrl->ctrl.queue_count = nr_io_queues + 1;
- if (ctrl->ctrl.queue_count < 2)
- return 0;
+ if (ctrl->ctrl.queue_count < 2) {
+ dev_err(ctrl->ctrl.device,
+ "unable to set any I/O queues\n");
+ return -ENOMEM;
+ }

dev_info(ctrl->ctrl.device,
"creating %d I/O queues.\n", nr_io_queues);
--
2.30.1