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Message-Id: <3cf9407f8fa1b73845d0a23e2f7445b5633d626d.1648981571.git.asml.silence@gmail.com>
Date: Sun, 3 Apr 2022 14:06:19 +0100
From: Pavel Begunkov <asml.silence@...il.com>
To: netdev@...r.kernel.org, "David S . Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>
Cc: Eric Dumazet <edumazet@...gle.com>, Wei Liu <wei.liu@...nel.org>,
Paul Durrant <paul@....org>,
Pavel Begunkov <asml.silence@...il.com>
Subject: [PATCH net-next 07/27] skbuff: introduce skb_is_zcopy()
Add a new helper function called skb_is_zcopy() for checking for an skb
zerocopy status. Before we were using skb_zcopy() for that, but it's
slightly heavier and generates extra code. Note: since the previous
patch we should have a ubuf set IFF an skb is SKBFL_ZEROCOPY_ENABLE
marked apart from nouarg cases.
Signed-off-by: Pavel Begunkov <asml.silence@...il.com>
---
include/linux/skbuff.h | 25 +++++++++++++++----------
net/core/skbuff.c | 15 +++++++--------
2 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 10f94b1909da..410850832b6a 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1647,11 +1647,14 @@ static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
return &skb_shinfo(skb)->hwtstamps;
}
-static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
+static inline bool skb_is_zcopy(struct sk_buff *skb)
{
- bool is_zcopy = skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
+ return skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
+}
- return is_zcopy ? skb_uarg(skb) : NULL;
+static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
+{
+ return skb_is_zcopy(skb) ? skb_uarg(skb) : NULL;
}
static inline bool skb_zcopy_pure(const struct sk_buff *skb)
@@ -1679,7 +1682,7 @@ static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
bool *have_ref)
{
- if (uarg && !skb_zcopy(skb)) {
+ if (uarg && !skb_is_zcopy(skb)) {
if (unlikely(have_ref && *have_ref))
*have_ref = false;
else
@@ -1723,11 +1726,13 @@ static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
/* Release a reference on a zerocopy structure */
static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
{
- struct ubuf_info *uarg = skb_zcopy(skb);
- if (uarg) {
- if (!skb_zcopy_is_nouarg(skb))
+ if (skb_is_zcopy(skb)) {
+ if (!skb_zcopy_is_nouarg(skb)) {
+ struct ubuf_info *uarg = skb_zcopy(skb);
+
uarg->callback(skb, uarg, zerocopy_success);
+ }
skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
}
@@ -3023,7 +3028,7 @@ static inline void skb_orphan(struct sk_buff *skb)
*/
static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
{
- if (likely(!skb_zcopy(skb)))
+ if (likely(!skb_is_zcopy(skb)))
return 0;
if (!skb_zcopy_is_nouarg(skb) &&
skb_uarg(skb)->callback == msg_zerocopy_callback)
@@ -3034,7 +3039,7 @@ static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
/* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
{
- if (likely(!skb_zcopy(skb)))
+ if (likely(!skb_is_zcopy(skb)))
return 0;
return skb_copy_ubufs(skb, gfp_mask);
}
@@ -3591,7 +3596,7 @@ static inline int skb_add_data(struct sk_buff *skb,
static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
const struct page *page, int off)
{
- if (skb_zcopy(skb))
+ if (skb_is_zcopy(skb))
return false;
if (i) {
const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7680314038b4..f7842bfdd7ae 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1350,14 +1350,13 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
struct msghdr *msg, int len,
struct ubuf_info *uarg)
{
- struct ubuf_info *orig_uarg = skb_zcopy(skb);
struct iov_iter orig_iter = msg->msg_iter;
int err, orig_len = skb->len;
/* An skb can only point to one uarg. This edge case happens when
* TCP appends to an skb, but zerocopy_realloc triggered a new alloc.
*/
- if (orig_uarg && uarg != orig_uarg)
+ if (skb_is_zcopy(skb) && uarg != skb_zcopy(skb))
return -EEXIST;
err = __zerocopy_sg_from_iter(sk, skb, &msg->msg_iter, len);
@@ -1380,9 +1379,9 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_iter_stream);
static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig,
gfp_t gfp_mask)
{
- if (skb_zcopy(orig)) {
- if (skb_zcopy(nskb)) {
- /* !gfp_mask callers are verified to !skb_zcopy(nskb) */
+ if (skb_is_zcopy(orig)) {
+ if (skb_is_zcopy(nskb)) {
+ /* !gfp_mask callers are verified to !skb_is_zcopy(nskb) */
if (!gfp_mask) {
WARN_ON_ONCE(1);
return -ENOMEM;
@@ -1721,8 +1720,8 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
if (skb_cloned(skb)) {
if (skb_orphan_frags(skb, gfp_mask))
goto nofrags;
- if (skb_zcopy(skb))
- refcount_inc(&skb_uarg(skb)->refcnt);
+ if (skb_is_zcopy(skb))
+ net_zcopy_get(skb_uarg(skb));
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
skb_frag_ref(skb, i);
@@ -3535,7 +3534,7 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
if (skb_headlen(skb))
return 0;
- if (skb_zcopy(tgt) || skb_zcopy(skb))
+ if (skb_is_zcopy(tgt) || skb_is_zcopy(skb))
return 0;
todo = shiftlen;
--
2.35.1
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