Commit 8b43ced6 authored by Prabhakar Kushwaha's avatar Prabhakar Kushwaha Committed by Christoph Hellwig
Browse files

nvme-tcp: use __dev_get_by_name instead dev_get_by_name for OPT_HOST_IFACE 



dev_get_by_name() finds network device by name but it also increases the
reference count.

If a nvme-tcp queue is present and the network device driver is removed
before nvme_tcp, we will face the following continuous log:

  "kernel:unregister_netdevice: waiting for <eth> to become free. Usage count = 2"

And rmmod further halts. Similar case arises during reboot/shutdown
with nvme-tcp queue present and both never completes.

To fix this, use __dev_get_by_name() which finds network device by
name without increasing any reference counter.

Fixes: 3ede8f72 ("nvme-tcp: allow selecting the network interface for connections")
Signed-off-by: default avatarOmkar Kulkarni <okulkarni@marvell.com>
Signed-off-by: default avatarShai Malin <smalin@marvell.com>
Signed-off-by: default avatarPrabhakar Kushwaha <pkushwaha@marvell.com>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
[hch: remove the ->ndev member entirely]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent a731763f

drivers/nvme/host/tcp.c

+1 −3
Original line number Diff line number Diff line
@@ -123,7 +123,6 @@ struct nvme_tcp_ctrl { 
	struct blk_mq_tag_set	admin_tag_set;

	struct sockaddr_storage addr;

	struct sockaddr_storage src_addr;

	struct net_device	*ndev;

	struct nvme_ctrl	ctrl;



	struct work_struct	err_work;
@@ -2533,8 +2532,7 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev, 
	}



	if (opts->mask & NVMF_OPT_HOST_IFACE) {

		ctrl->ndev = dev_get_by_name(&init_net, opts->host_iface);

		if (!ctrl->ndev) {

		if (!__dev_get_by_name(&init_net, opts->host_iface)) {

			pr_err("invalid interface passed: %s\n",

			       opts->host_iface);

			ret = -ENODEV;