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authorHannes Frederic Sowa <hannes@stressinduktion.org>2015-05-21 17:00:00 +0200
committerDavid S. Miller <davem@davemloft.net>2015-05-25 00:06:59 -0400
commita60e3cc7c92973a31fad0fd04dc5cf4355d3d1ef (patch)
treefccece19424d49db1c03ef8f204f3c7ca3478a4a
parent869e7c62486ec0e170a9771acaa251d1a33b5871 (diff)
downloadlinux-a60e3cc7c92973a31fad0fd04dc5cf4355d3d1ef.tar.gz
net: make skb_splice_bits more configureable
Prepare skb_splice_bits to be able to deal with AF_UNIX sockets. AF_UNIX sockets don't use lock_sock/release_sock and thus we have to use a callback to make the locking and unlocking configureable. Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/skbuff.h11
-rw-r--r--net/core/skbuff.c45
-rw-r--r--net/ipv4/tcp.c5
3 files changed, 40 insertions, 21 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f708936cdd23..6b41c15efa27 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -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.
*
@@ -2699,9 +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,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4f2babeaf18d..02769fa4f5c8 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -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;
/*
@@ -1914,20 +1937,8 @@ 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;
}
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 90afcec3f427..65f791f74845 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -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;