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: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jonathan Lemon 2021-01-06 14:18:40 -08:00 committed by Jakub Kicinski
parent 04c2d33eab
commit 9ee5e5ade0
4 changed files with 10 additions and 6 deletions

View File

@ -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);

View File

@ -1814,8 +1814,7 @@ drop:
/* 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);

View File

@ -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;

View File

@ -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);
}
}