io_uring: add support for sendmsg()

This is done through IORING_OP_SENDMSG. There's a new sqe->msg_flags
for the flags argument, and the msghdr struct is passed in the
sqe->addr field.

We use MSG_DONTWAIT to force an inline fast path if sendmsg() doesn't
block, and punt to async execution if it would have.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2019-04-19 13:34:07 -06:00
parent 9e645e1105
commit 0fa03c624d
4 changed files with 53 additions and 0 deletions

View file

@ -2313,6 +2313,13 @@ out_freeiov:
/*
* BSD sendmsg interface
*/
long __sys_sendmsg_sock(struct socket *sock, struct user_msghdr __user *msg,
unsigned int flags)
{
struct msghdr msg_sys;
return ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0);
}
long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
bool forbid_cmsg_compat)