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skb_splice_bits(): get rid of callback

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since pipe_lock is the outermost now, we don't need to drop/regain
socket locks around the call of splice_to_pipe() from skb_splice_bits(),
which kills the need to have a socket-specific callback; we can just
call splice_to_pipe() and be done with that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-09-17 21:02:10 -04:00
parent 79fddc4efd
commit 25869262ef
5 changed files with 6 additions and 66 deletions
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8
include/linux/skbuff.h
View file

@ -3021,15 +3021,9 @@ 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);
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,
ssize_t (*splice_cb)(struct sock *,
struct pipe_inode_info *,
struct splice_pipe_desc *));
unsigned int flags);
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,

28
net/core/skbuff.c
View file

@ -1962,37 +1962,13 @@ 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.
*/
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,
ssize_t (*splice_cb)(struct sock *,
struct pipe_inode_info *,
struct splice_pipe_desc *))
unsigned int flags)
{
struct partial_page partial[MAX_SKB_FRAGS];
struct page *pages[MAX_SKB_FRAGS];
@ -2009,7 +1985,7 @@ int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk);
if (spd.nr_pages)
ret = splice_cb(sk, pipe, &spd);
ret = splice_to_pipe(pipe, &spd);
return ret;
}

3
net/ipv4/tcp.c
View file

@ -688,8 +688,7 @@ static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
int ret;
ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
min(rd_desc->count, len), tss->flags,
skb_socket_splice);
min(rd_desc->count, len), tss->flags);
if (ret > 0)
rd_desc->count -= ret;
return ret;

16
net/kcm/kcmsock.c
View file

@ -1462,19 +1462,6 @@ static int kcm_recvmsg(struct socket *sock, struct msghdr *msg,
return copied ? : err;
}
static ssize_t kcm_sock_splice(struct sock *sk,
struct pipe_inode_info *pipe,
struct splice_pipe_desc *spd)
{
int ret;
release_sock(sk);
ret = splice_to_pipe(pipe, spd);
lock_sock(sk);
return ret;
}
static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
@ -1504,8 +1491,7 @@ static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
if (len > rxm->full_len)
len = rxm->full_len;
copied = skb_splice_bits(skb, sk, rxm->offset, pipe, len, flags,
kcm_sock_splice);
copied = skb_splice_bits(skb, sk, rxm->offset, pipe, len, flags);
if (copied < 0) {
err = copied;
goto err_out;

17
net/unix/af_unix.c
View file

@ -2475,28 +2475,13 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
return unix_stream_read_generic(&state);
}
static ssize_t skb_unix_socket_splice(struct sock *sk,
struct pipe_inode_info *pipe,
struct splice_pipe_desc *spd)
{
int ret;
struct unix_sock *u = unix_sk(sk);
mutex_unlock(&u->iolock);
ret = splice_to_pipe(pipe, spd);
mutex_lock(&u->iolock);
return ret;
}
static int unix_stream_splice_actor(struct sk_buff *skb,
int skip, int chunk,
struct unix_stream_read_state *state)
{
return skb_splice_bits(skb, state->socket->sk,
UNIXCB(skb).consumed + skip,
state->pipe, chunk, state->splice_flags,
skb_unix_socket_splice);
state->pipe, chunk, state->splice_flags);
}
static ssize_t unix_stream_splice_read(struct socket *sock, loff_t *ppos,