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ip: convert tcp_sendmsg() to iov_iter primitives

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patch is actually smaller than it seems to be - most of it is unindenting
the inner loop body in tcp_sendmsg() itself...

the bit in tcp_input.c is going to get reverted very soon - that's what
memcpy_from_msg() will become, but not in this commit; let's keep it
reasonably contained...

There's one potentially subtle change here: in case of short copy from
userland, mainline tcp_send_syn_data() discards the skb it has allocated
and falls back to normal path, where we'll send as much as possible after
rereading the same data again.  This patch trims SYN+data skb instead -
that way we don't need to copy from the same place twice.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2014-11-28 13:40:20 -05:00
parent cacdc7d2f9
commit 57be5bdad7
4 changed files with 127 additions and 145 deletions
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18
include/net/sock.h
View File

@ -1803,27 +1803,25 @@ static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
}
static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
char __user *from, char *to,
struct iov_iter *from, char *to,
int copy, int offset)
{
if (skb->ip_summed == CHECKSUM_NONE) {
int err = 0;
__wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
if (err)
return err;
__wsum csum = 0;
if (csum_and_copy_from_iter(to, copy, &csum, from) != copy)
return -EFAULT;
skb->csum = csum_block_add(skb->csum, csum, offset);
} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
if (!access_ok(VERIFY_READ, from, copy) ||
__copy_from_user_nocache(to, from, copy))
if (copy_from_iter_nocache(to, copy, from) != copy)
return -EFAULT;
} else if (copy_from_user(to, from, copy))
} else if (copy_from_iter(to, copy, from) != copy)
return -EFAULT;
return 0;
}
static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
char __user *from, int copy)
struct iov_iter *from, int copy)
{
int err, offset = skb->len;
@ -1835,7 +1833,7 @@ static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
return err;
}
static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
struct sk_buff *skb,
struct page *page,
int off, int copy)