Commit 9ee5e5ad authored by Jonathan Lemon's avatar Jonathan Lemon Committed by Jakub Kicinski
Browse files

tap/tun: add skb_zcopy_init() helper for initialization. 



Replace direct assignments with skb_zcopy_init() for zerocopy
cases where a new skb is initialized, without changing the
reference counts.

Signed-off-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 04c2d33e

drivers/net/tap.c

+1 −2
Original line number Diff line number Diff line
@@ -722,8 +722,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, 
	tap = rcu_dereference(q->tap);

	/* copy skb_ubuf_info for callback when skb has no error */

	if (zerocopy) {

		skb_shinfo(skb)->destructor_arg = msg_control;

		skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;

		skb_zcopy_init(skb, msg_control);

	} else if (msg_control) {

		struct ubuf_info *uarg = msg_control;

		uarg->callback(NULL, uarg, false);

drivers/net/tun.c

+1 −2
Original line number Diff line number Diff line
@@ -1814,8 +1814,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, 


	/* copy skb_ubuf_info for callback when skb has no error */

	if (zerocopy) {

		skb_shinfo(skb)->destructor_arg = msg_control;

		skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;

		skb_zcopy_init(skb, msg_control);

	} else if (msg_control) {

		struct ubuf_info *uarg = msg_control;

		uarg->callback(NULL, uarg, false);

drivers/vhost/net.c

+1 −0
Original line number Diff line number Diff line
@@ -903,6 +903,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) 
			ubuf->callback = vhost_zerocopy_callback;

			ubuf->ctx = nvq->ubufs;

			ubuf->desc = nvq->upend_idx;

			ubuf->flags = SKBFL_ZEROCOPY_FRAG;

			refcount_set(&ubuf->refcnt, 1);

			msg.msg_control = &ctl;

			ctl.type = TUN_MSG_UBUF;

include/linux/skbuff.h

+7 −2
Original line number Diff line number Diff line
@@ -1448,6 +1448,12 @@ static inline void skb_zcopy_get(struct ubuf_info *uarg) 
	refcount_inc(&uarg->refcnt);

}



static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)

{

	skb_shinfo(skb)->destructor_arg = uarg;

	skb_shinfo(skb)->flags |= uarg->flags;

}



static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,

				 bool *have_ref)

{
@@ -1456,8 +1462,7 @@ static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg, 
			*have_ref = false;

		else

			skb_zcopy_get(uarg);

		skb_shinfo(skb)->destructor_arg = uarg;

		skb_shinfo(skb)->flags |= uarg->flags;

		skb_zcopy_init(skb, uarg);

	}

}