linux-kernel - [PATCH net-next v9 02/16] net: Pass max frags into skb_append

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Message-Id: <20230518130713.1515729-3-dhowells@redhat.com>
Date:   Thu, 18 May 2023 14:06:59 +0100
From:   David Howells <dhowells@...hat.com>
To:     netdev@...r.kernel.org
Cc:     David Howells <dhowells@...hat.com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Willem de Bruijn <willemdebruijn.kernel@...il.com>,
        David Ahern <dsahern@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Al Viro <viro@...iv.linux.org.uk>,
        Christoph Hellwig <hch@...radead.org>,
        Jens Axboe <axboe@...nel.dk>, Jeff Layton <jlayton@...nel.org>,
        Christian Brauner <brauner@...nel.org>,
        Chuck Lever III <chuck.lever@...cle.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org
Subject: [PATCH net-next v9 02/16] net: Pass max frags into skb_append_pagefrags()

Pass the maximum number of fragments into skb_append_pagefrags() rather
than using MAX_SKB_FRAGS so that it can be used from code that wants to
specify sysctl_max_skb_frags.

Signed-off-by: David Howells <dhowells@...hat.com>
cc: Eric Dumazet <edumazet@...gle.com>
cc: "David S. Miller" <davem@...emloft.net>
cc: David Ahern <dsahern@...nel.org>
cc: Jakub Kicinski <kuba@...nel.org>
cc: Paolo Abeni <pabeni@...hat.com>
cc: Jens Axboe <axboe@...nel.dk>
cc: Matthew Wilcox <willy@...radead.org>
cc: netdev@...r.kernel.org
---
 include/linux/skbuff.h | 2 +-
 net/core/skbuff.c      | 4 ++--
 net/ipv4/ip_output.c   | 3 ++-
 net/unix/af_unix.c     | 2 +-
 4 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 8cff3d817131..15011408c47c 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1383,7 +1383,7 @@ static inline int skb_pad(struct sk_buff *skb, int pad)
 #define dev_kfree_skb(a)	consume_skb(a)
 
 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
-			 int offset, size_t size);
+			 int offset, size_t size, size_t max_frags);
 
 struct skb_seq_state {
 	__u32		lower_offset;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6724a84ebb09..7f53dcb26ad3 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4188,13 +4188,13 @@ unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
 EXPORT_SYMBOL(skb_find_text);
 
 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
-			 int offset, size_t size)
+			 int offset, size_t size, size_t max_frags)
 {
 	int i = skb_shinfo(skb)->nr_frags;
 
 	if (skb_can_coalesce(skb, i, page, offset)) {
 		skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size);
-	} else if (i < MAX_SKB_FRAGS) {
+	} else if (i < max_frags) {
 		skb_zcopy_downgrade_managed(skb);
 		get_page(page);
 		skb_fill_page_desc_noacc(skb, i, page, offset, size);
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 61892268e8a6..52fc840898d8 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1450,7 +1450,8 @@ ssize_t	ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 		if (len > size)
 			len = size;
 
-		if (skb_append_pagefrags(skb, page, offset, len)) {
+		if (skb_append_pagefrags(skb, page, offset, len,
+					 MAX_SKB_FRAGS)) {
 			err = -EMSGSIZE;
 			goto error;
 		}
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index cc695c9f09ec..dd55506b4632 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2349,7 +2349,7 @@ static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
 		newskb = NULL;
 	}
 
-	if (skb_append_pagefrags(skb, page, offset, size)) {
+	if (skb_append_pagefrags(skb, page, offset, size, MAX_SKB_FRAGS)) {
 		tail = skb;
 		goto alloc_skb;
 	}