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>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4f2babe..02769fa 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1870,15 +1870,39 @@
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 @@
.spd_release = sock_spd_release,
};
struct sk_buff *frag_iter;
- struct sock *sk = skb->sk;
int ret = 0;
/*
@@ -1914,20 +1937,8 @@
}
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;
}
