Commit 9a2d9389 authored by Vlad Buslov's avatar Vlad Buslov Committed by David S. Miller
Browse files

net: sched: flower: handle concurrent filter insertion in fl_change 



Check if user specified a handle and another filter with the same handle
was inserted concurrently. Return EAGAIN to retry filter processing (in
case it is an overwrite request).

Signed-off-by: default avatarVlad Buslov <vladbu@mellanox.com>
Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
Reviewed-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 259e60f9

net/sched/cls_flower.c

+9 −0
Original line number Diff line number Diff line
@@ -1542,6 +1542,15 @@ static int fl_change(struct net *net, struct sk_buff *in_skb, 
			/* user specifies a handle and it doesn't exist */

			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,

					    handle, GFP_ATOMIC);



			/* Filter with specified handle was concurrently

			 * inserted after initial check in cls_api. This is not

			 * necessarily an error if NLM_F_EXCL is not set in

			 * message flags. Returning EAGAIN will cause cls_api to

			 * try to update concurrently inserted rule.

			 */

			if (err == -ENOSPC)

				err = -EAGAIN;

		} else {

			handle = 1;

			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,

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