Commit b10e3d6c authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'af_unix_sendpage' 



Hannes Frederic Sowa says:

====================
net: af_unix: zerocopy stream bits

This series implements zerocopy support for AF_UNIX SOCK_STREAM sockets.

Changelog in the specific patches. Thanks to all the reviewers!
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents d98c3edc 2b514574

fs/splice.c

+1 −0
Original line number Diff line number Diff line
@@ -261,6 +261,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe, 


	return ret;

}

EXPORT_SYMBOL_GPL(splice_to_pipe);



void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)

{

include/linux/skbuff.h

+12 −2
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <linux/netdev_features.h>

#include <linux/sched.h>

#include <net/flow_dissector.h>

#include <linux/splice.h>



/* A. Checksumming of received packets by device.

 *
@@ -861,6 +862,9 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 
					int len, int odd, struct sk_buff *skb),

			    void *from, int length);



int skb_append_pagefrags(struct sk_buff *skb, struct page *page,

			 int offset, size_t size);



struct skb_seq_state {

	__u32		lower_offset;

	__u32		upper_offset;
@@ -2696,9 +2700,15 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 
int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);

__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,

			      int len, __wsum csum);

int skb_splice_bits(struct sk_buff *skb, unsigned int offset,

ssize_t skb_socket_splice(struct sock *sk,

			  struct pipe_inode_info *pipe,

			  struct splice_pipe_desc *spd);

int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,

		    struct pipe_inode_info *pipe, unsigned int len,

		    unsigned int flags);

		    unsigned int flags,

		    ssize_t (*splice_cb)(struct sock *,

					 struct pipe_inode_info *,

					 struct splice_pipe_desc *));

void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);

unsigned int skb_zerocopy_headlen(const struct sk_buff *from);

int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,

net/core/skbuff.c

+47 −17
Original line number Diff line number Diff line
@@ -1870,15 +1870,39 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, 
	return false;

}



ssize_t skb_socket_splice(struct sock *sk,

			  struct pipe_inode_info *pipe,

			  struct splice_pipe_desc *spd)

{

	int ret;



	/* Drop the socket lock, otherwise we have reverse

	 * locking dependencies between sk_lock and i_mutex

	 * here as compared to sendfile(). We enter here

	 * with the socket lock held, and splice_to_pipe() will

	 * grab the pipe inode lock. For sendfile() emulation,

	 * we call into ->sendpage() with the i_mutex lock held

	 * and networking will grab the socket lock.

	 */

	release_sock(sk);

	ret = splice_to_pipe(pipe, spd);

	lock_sock(sk);



	return ret;

}



/*

 * Map data from the skb to a pipe. Should handle both the linear part,

 * the fragments, and the frag list. It does NOT handle frag lists within

 * the frag list, if such a thing exists. We'd probably need to recurse to

 * handle that cleanly.

 */

int skb_splice_bits(struct sk_buff *skb, unsigned int offset,

int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,

		    struct pipe_inode_info *pipe, unsigned int tlen,

		    unsigned int flags)

		    unsigned int flags,

		    ssize_t (*splice_cb)(struct sock *,

					 struct pipe_inode_info *,

					 struct splice_pipe_desc *))

{

	struct partial_page partial[MAX_SKB_FRAGS];

	struct page *pages[MAX_SKB_FRAGS];
@@ -1891,7 +1915,6 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, 
		.spd_release = sock_spd_release,

	};

	struct sk_buff *frag_iter;

	struct sock *sk = skb->sk;

	int ret = 0;



	/*
@@ -1914,23 +1937,12 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, 
	}



done:

	if (spd.nr_pages) {

		/*

		 * Drop the socket lock, otherwise we have reverse

		 * locking dependencies between sk_lock and i_mutex

		 * here as compared to sendfile(). We enter here

		 * with the socket lock held, and splice_to_pipe() will

		 * grab the pipe inode lock. For sendfile() emulation,

		 * we call into ->sendpage() with the i_mutex lock held

		 * and networking will grab the socket lock.

		 */

		release_sock(sk);

		ret = splice_to_pipe(pipe, &spd);

		lock_sock(sk);

	}

	if (spd.nr_pages)

		ret = splice_cb(sk, pipe, &spd);



	return ret;

}

EXPORT_SYMBOL_GPL(skb_splice_bits);



/**

 *	skb_store_bits - store bits from kernel buffer to skb
@@ -2915,6 +2927,24 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 
}

EXPORT_SYMBOL(skb_append_datato_frags);



int skb_append_pagefrags(struct sk_buff *skb, struct page *page,

			 int offset, size_t size)

{

	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) {

		get_page(page);

		skb_fill_page_desc(skb, i, page, offset, size);

	} else {

		return -EMSGSIZE;

	}



	return 0;

}

EXPORT_SYMBOL_GPL(skb_append_pagefrags);



/**

 *	skb_pull_rcsum - pull skb and update receive checksum

 *	@skb: buffer to update

net/ipv4/ip_output.c

+4 −11
Original line number Diff line number Diff line
@@ -1233,11 +1233,9 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 
	}



	while (size > 0) {

		int i;



		if (skb_is_gso(skb))

		if (skb_is_gso(skb)) {

			len = size;

		else {

		} else {



			/* Check if the remaining data fits into current packet. */

			len = mtu - skb->len;
@@ -1289,15 +1287,10 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 
			continue;

		}



		i = skb_shinfo(skb)->nr_frags;

		if (len > size)

			len = size;

		if (skb_can_coalesce(skb, i, page, offset)) {

			skb_frag_size_add(&skb_shinfo(skb)->frags[i-1], len);

		} else if (i < MAX_SKB_FRAGS) {

			get_page(page);

			skb_fill_page_desc(skb, i, page, offset, len);

		} else {



		if (skb_append_pagefrags(skb, page, offset, len)) {

			err = -EMSGSIZE;

			goto error;

		}

net/ipv4/tcp.c

+3 −2
Original line number Diff line number Diff line
@@ -695,8 +695,9 @@ static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 
	struct tcp_splice_state *tss = rd_desc->arg.data;

	int ret;



	ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),

			      tss->flags);

	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,

			      min(rd_desc->count, len), tss->flags,

			      skb_socket_splice);

	if (ret > 0)

		rd_desc->count -= ret;

	return ret;

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