From 022ca2fc7fe08d51f33a1d23a9be49e6d132914e Mon Sep 17 00:00:00 2001
From: Alan Somers <asomers@FreeBSD.org>
Date: Sat, 2 Jan 2021 16:34:20 -0700
Subject: Add aio_writev and aio_readv

POSIX AIO is great, but it lacks vectored I/O functions. This commit
fixes that shortcoming by adding aio_writev and aio_readv. They aren't
part of the standard, but they're an obvious extension. They work just
like their synchronous equivalents pwritev and preadv.

It isn't yet possible to use vectored aiocbs with lio_listio, but that
could be added in the future.

Reviewed by:    jhb, kib, bcr
Relnotes:       yes
Differential Revision: https://reviews.freebsd.org/D27743
---
 sys/kern/sys_socket.c | 35 +++++++++++++++--------------------
 1 file changed, 15 insertions(+), 20 deletions(-)

(limited to 'sys/kern/sys_socket.c')

diff --git a/sys/kern/sys_socket.c b/sys/kern/sys_socket.c
index 0fe200c119d2..18803b6a5ac0 100644
--- a/sys/kern/sys_socket.c
+++ b/sys/kern/sys_socket.c
@@ -600,9 +600,7 @@ soaio_process_job(struct socket *so, struct sockbuf *sb, struct kaiocb *job)
 	struct ucred *td_savedcred;
 	struct thread *td;
 	struct file *fp;
-	struct uio uio;
-	struct iovec iov;
-	size_t cnt, done;
+	size_t cnt, done, job_total_nbytes;
 	long ru_before;
 	int error, flags;
 
@@ -614,16 +612,11 @@ retry:
 	td_savedcred = td->td_ucred;
 	td->td_ucred = job->cred;
 
+	job_total_nbytes = job->uiop->uio_resid + job->aio_done;
 	done = job->aio_done;
-	cnt = job->uaiocb.aio_nbytes - done;
-	iov.iov_base = (void *)((uintptr_t)job->uaiocb.aio_buf + done);
-	iov.iov_len = cnt;
-	uio.uio_iov = &iov;
-	uio.uio_iovcnt = 1;
-	uio.uio_offset = 0;
-	uio.uio_resid = cnt;
-	uio.uio_segflg = UIO_USERSPACE;
-	uio.uio_td = td;
+	cnt = job->uiop->uio_resid;
+	job->uiop->uio_offset = 0;
+	job->uiop->uio_td = td;
 	flags = MSG_NBIO;
 
 	/*
@@ -633,26 +626,26 @@ retry:
 	 */
 
 	if (sb == &so->so_rcv) {
-		uio.uio_rw = UIO_READ;
 		ru_before = td->td_ru.ru_msgrcv;
 #ifdef MAC
 		error = mac_socket_check_receive(fp->f_cred, so);
 		if (error == 0)
 
 #endif
-			error = soreceive(so, NULL, &uio, NULL, NULL, &flags);
+			error = soreceive(so, NULL, job->uiop, NULL, NULL,
+			    &flags);
 		if (td->td_ru.ru_msgrcv != ru_before)
 			job->msgrcv = 1;
 	} else {
 		if (!TAILQ_EMPTY(&sb->sb_aiojobq))
 			flags |= MSG_MORETOCOME;
-		uio.uio_rw = UIO_WRITE;
 		ru_before = td->td_ru.ru_msgsnd;
 #ifdef MAC
 		error = mac_socket_check_send(fp->f_cred, so);
 		if (error == 0)
 #endif
-			error = sosend(so, NULL, &uio, NULL, NULL, flags, td);
+			error = sosend(so, NULL, job->uiop, NULL, NULL, flags,
+			    td);
 		if (td->td_ru.ru_msgsnd != ru_before)
 			job->msgsnd = 1;
 		if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
@@ -662,7 +655,7 @@ retry:
 		}
 	}
 
-	done += cnt - uio.uio_resid;
+	done += cnt - job->uiop->uio_resid;
 	job->aio_done = done;
 	td->td_ucred = td_savedcred;
 
@@ -676,7 +669,7 @@ retry:
 		 * been made, requeue this request at the head of the
 		 * queue to try again when the socket is ready.
 		 */
-		MPASS(done != job->uaiocb.aio_nbytes);
+		MPASS(done != job_total_nbytes);
 		SOCKBUF_LOCK(sb);
 		if (done == 0 || !(so->so_state & SS_NBIO)) {
 			empty_results++;
@@ -782,10 +775,10 @@ soo_aio_cancel(struct kaiocb *job)
 
 	so = job->fd_file->f_data;
 	opcode = job->uaiocb.aio_lio_opcode;
-	if (opcode == LIO_READ)
+	if (opcode == LIO_READ || opcode == LIO_READV)
 		sb = &so->so_rcv;
 	else {
-		MPASS(opcode == LIO_WRITE);
+		MPASS(opcode == LIO_WRITE || opcode == LIO_WRITEV);
 		sb = &so->so_snd;
 	}
 
@@ -817,9 +810,11 @@ soo_aio_queue(struct file *fp, struct kaiocb *job)
 
 	switch (job->uaiocb.aio_lio_opcode) {
 	case LIO_READ:
+	case LIO_READV:
 		sb = &so->so_rcv;
 		break;
 	case LIO_WRITE:
+	case LIO_WRITEV:
 		sb = &so->so_snd;
 		break;
 	default:
-- 
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