[PATCH 4.20 15/80] tun: move the call to tun_set_real_num_queues

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: George Amanakis <gamanakis@xxxxxxxxx>

[ Upstream commit 3a03cb8456cc1d61c467a5375e0a10e5207b948c ]

Call tun_set_real_num_queues() after the increment of tun->numqueues
since the former depends on it. Otherwise, the number of queues is not
correctly accounted for, which results to warnings similar to:
"vnet0 selects TX queue 11, but real number of TX queues is 11".

Fixes: 0b7959b62573 ("tun: publish tfile after it's fully initialized")
Reported-and-tested-by: George Amanakis <gamanakis@xxxxxxxxx>
Signed-off-by: George Amanakis <gamanakis@xxxxxxxxx>
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/tun.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -862,8 +862,6 @@ static int tun_attach(struct tun_struct
 	if (rtnl_dereference(tun->xdp_prog))
 		sock_set_flag(&tfile->sk, SOCK_XDP);
 
-	tun_set_real_num_queues(tun);
-
 	/* device is allowed to go away first, so no need to hold extra
 	 * refcnt.
 	 */
@@ -875,6 +873,7 @@ static int tun_attach(struct tun_struct
 	rcu_assign_pointer(tfile->tun, tun);
 	rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
 	tun->numqueues++;
+	tun_set_real_num_queues(tun);
 out:
 	return err;
 }