use less confusing names for iov_iter direction initializers

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

18 files changed, 40 insertions, 39 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index aaa37b07e30a..0638b12055ba 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -2043,7 +2043,7 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
 	struct kvec kv = {.iov_base = data, .iov_len = count};
 	struct iov_iter to;
 
-	iov_iter_kvec(&to, READ, &kv, 1, count);
+	iov_iter_kvec(&to, ITER_DEST, &kv, 1, count);
 
 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
 		 fid->fid, offset, count);
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 215af9b3b589..d57b2e3ece2a 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -441,7 +441,7 @@ static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 	iv.iov_len = skb->len;
 
 	memset(&msg, 0, sizeof(msg));
-	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iv, 1, skb->len);
 
 	err = l2cap_chan_send(chan, &msg, skb->len);
 	if (err > 0) {
diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index 1fcc482397c3..e7adb8a98cf9 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -56,7 +56,7 @@ static void a2mp_send(struct amp_mgr *mgr, u8 code, u8 ident, u16 len, void *dat
 
 	memset(&msg, 0, sizeof(msg));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, total_len);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iv, 1, total_len);
 
 	l2cap_chan_send(chan, &msg, total_len);
 
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 11f853d0500f..70663229b3cc 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -605,7 +605,7 @@ static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
 
 	memset(&msg, 0, sizeof(msg));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len);
 
 	l2cap_chan_send(chan, &msg, 1 + len);
 
diff --git a/net/ceph/messenger_v1.c b/net/ceph/messenger_v1.c
index 3ddbde87e4d6..d1787d7d33ef 100644
--- a/net/ceph/messenger_v1.c
+++ b/net/ceph/messenger_v1.c
@@ -30,7 +30,7 @@ static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
 	if (!buf)
 		msg.msg_flags |= MSG_TRUNC;
 
-	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, len);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, len);
 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
 	if (r == -EAGAIN)
 		r = 0;
@@ -49,7 +49,7 @@ static int ceph_tcp_recvpage(struct socket *sock, struct page *page,
 	int r;
 
 	BUG_ON(page_offset + length > PAGE_SIZE);
-	iov_iter_bvec(&msg.msg_iter, READ, &bvec, 1, length);
+	iov_iter_bvec(&msg.msg_iter, ITER_DEST, &bvec, 1, length);
 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
 	if (r == -EAGAIN)
 		r = 0;
diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
index cc8ff81a50b7..3009028c4fa2 100644
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -168,7 +168,7 @@ static int do_try_sendpage(struct socket *sock, struct iov_iter *it)
 						  bv.bv_offset, bv.bv_len,
 						  CEPH_MSG_FLAGS);
 		} else {
-			iov_iter_bvec(&msg.msg_iter, WRITE, &bv, 1, bv.bv_len);
+			iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bv, 1, bv.bv_len);
 			ret = sock_sendmsg(sock, &msg);
 		}
 		if (ret <= 0) {
@@ -225,7 +225,7 @@ static void reset_in_kvecs(struct ceph_connection *con)
 	WARN_ON(iov_iter_count(&con->v2.in_iter));
 
 	con->v2.in_kvec_cnt = 0;
-	iov_iter_kvec(&con->v2.in_iter, READ, con->v2.in_kvecs, 0, 0);
+	iov_iter_kvec(&con->v2.in_iter, ITER_DEST, con->v2.in_kvecs, 0, 0);
 }
 
 static void set_in_bvec(struct ceph_connection *con, const struct bio_vec *bv)
@@ -233,7 +233,7 @@ static void set_in_bvec(struct ceph_connection *con, const struct bio_vec *bv)
 	WARN_ON(iov_iter_count(&con->v2.in_iter));
 
 	con->v2.in_bvec = *bv;
-	iov_iter_bvec(&con->v2.in_iter, READ, &con->v2.in_bvec, 1, bv->bv_len);
+	iov_iter_bvec(&con->v2.in_iter, ITER_DEST, &con->v2.in_bvec, 1, bv->bv_len);
 }
 
 static void set_in_skip(struct ceph_connection *con, int len)
@@ -241,7 +241,7 @@ static void set_in_skip(struct ceph_connection *con, int len)
 	WARN_ON(iov_iter_count(&con->v2.in_iter));
 
 	dout("%s con %p len %d\n", __func__, con, len);
-	iov_iter_discard(&con->v2.in_iter, READ, len);
+	iov_iter_discard(&con->v2.in_iter, ITER_DEST, len);
 }
 
 static void add_out_kvec(struct ceph_connection *con, void *buf, int len)
@@ -265,7 +265,7 @@ static void reset_out_kvecs(struct ceph_connection *con)
 
 	con->v2.out_kvec_cnt = 0;
 
-	iov_iter_kvec(&con->v2.out_iter, WRITE, con->v2.out_kvecs, 0, 0);
+	iov_iter_kvec(&con->v2.out_iter, ITER_SOURCE, con->v2.out_kvecs, 0, 0);
 	con->v2.out_iter_sendpage = false;
 }
 
@@ -277,7 +277,7 @@ static void set_out_bvec(struct ceph_connection *con, const struct bio_vec *bv,
 
 	con->v2.out_bvec = *bv;
 	con->v2.out_iter_sendpage = zerocopy;
-	iov_iter_bvec(&con->v2.out_iter, WRITE, &con->v2.out_bvec, 1,
+	iov_iter_bvec(&con->v2.out_iter, ITER_SOURCE, &con->v2.out_bvec, 1,
 		      con->v2.out_bvec.bv_len);
 }
 
@@ -290,7 +290,7 @@ static void set_out_bvec_zero(struct ceph_connection *con)
 	con->v2.out_bvec.bv_offset = 0;
 	con->v2.out_bvec.bv_len = min(con->v2.out_zero, (int)PAGE_SIZE);
 	con->v2.out_iter_sendpage = true;
-	iov_iter_bvec(&con->v2.out_iter, WRITE, &con->v2.out_bvec, 1,
+	iov_iter_bvec(&con->v2.out_iter, ITER_SOURCE, &con->v2.out_bvec, 1,
 		      con->v2.out_bvec.bv_len);
 }
 
diff --git a/net/compat.c b/net/compat.c
index 385f04a6be2f..161b7bea1f62 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -95,7 +95,8 @@ int get_compat_msghdr(struct msghdr *kmsg,
 	if (err)
 		return err;
 
-	err = import_iovec(save_addr ? READ : WRITE, compat_ptr(msg.msg_iov), msg.msg_iovlen,
+	err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
+			   compat_ptr(msg.msg_iov), msg.msg_iovlen,
 			   UIO_FASTIOV, iov, &kmsg->msg_iter);
 	return err < 0 ? err : 0;
 }
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 54836a6b81d6..01cc5705b146 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2000,7 +2000,7 @@ static int receive_fallback_to_copy(struct sock *sk,
 	if (copy_address != zc->copybuf_address)
 		return -EINVAL;
 
-	err = import_single_range(READ, (void __user *)copy_address,
+	err = import_single_range(ITER_DEST, (void __user *)copy_address,
 				  inq, &iov, &msg.msg_iter);
 	if (err)
 		return err;
@@ -2034,7 +2034,7 @@ static int tcp_copy_straggler_data(struct tcp_zerocopy_receive *zc,
 	if (copy_address != zc->copybuf_address)
 		return -EINVAL;
 
-	err = import_single_range(READ, (void __user *)copy_address,
+	err = import_single_range(ITER_DEST, (void __user *)copy_address,
 				  copylen, &iov, &msg.msg_iter);
 	if (err)
 		return err;
diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index a56fd0b5a430..4963fec815da 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -1617,7 +1617,7 @@ ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
 	EnterFunction(7);
 
 	/* Receive a packet */
-	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, buflen);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, buflen);
 	len = sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 	if (len < 0)
 		return len;
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 1472f31480d8..dfb9797f7bc6 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -673,7 +673,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	 */
 	krflags = MSG_PEEK | MSG_WAITALL;
 	clc_sk->sk_rcvtimeo = timeout;
-	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1,
 			sizeof(struct smc_clc_msg_hdr));
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
 	if (signal_pending(current)) {
@@ -720,7 +720,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	} else {
 		recvlen = datlen;
 	}
-	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
 	krflags = MSG_WAITALL;
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
 	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
@@ -737,7 +737,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 		/* receive remaining proposal message */
 		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
 						SMC_CLC_RECV_BUF_LEN : datlen;
-		iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
+		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
 		len = sock_recvmsg(smc->clcsock, &msg, krflags);
 		datlen -= len;
 	}
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index 64dedffe9d26..f4b6a71ac488 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -308,7 +308,7 @@ int smc_tx_sendpage(struct smc_sock *smc, struct page *page, int offset,
 
 	iov.iov_base = kaddr + offset;
 	iov.iov_len = size;
-	iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, size);
 	rc = smc_tx_sendmsg(smc, &msg, size);
 	kunmap(page);
 	return rc;
diff --git a/net/socket.c b/net/socket.c
index 00da9ce3dba0..73463c7c3702 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -750,7 +750,7 @@ EXPORT_SYMBOL(sock_sendmsg);
 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 		   struct kvec *vec, size_t num, size_t size)
 {
-	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, num, size);
 	return sock_sendmsg(sock, msg);
 }
 EXPORT_SYMBOL(kernel_sendmsg);
@@ -776,7 +776,7 @@ int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 	if (!sock->ops->sendmsg_locked)
 		return sock_no_sendmsg_locked(sk, msg, size);
 
-	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, num, size);
 
 	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
 }
@@ -1034,7 +1034,7 @@ int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
 		   struct kvec *vec, size_t num, size_t size, int flags)
 {
 	msg->msg_control_is_user = false;
-	iov_iter_kvec(&msg->msg_iter, READ, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, ITER_DEST, vec, num, size);
 	return sock_recvmsg(sock, msg, flags);
 }
 EXPORT_SYMBOL(kernel_recvmsg);
@@ -2092,7 +2092,7 @@ int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
 	struct iovec iov;
 	int fput_needed;
 
-	err = import_single_range(WRITE, buff, len, &iov, &msg.msg_iter);
+	err = import_single_range(ITER_SOURCE, buff, len, &iov, &msg.msg_iter);
 	if (unlikely(err))
 		return err;
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
@@ -2157,7 +2157,7 @@ int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
 	int err, err2;
 	int fput_needed;
 
-	err = import_single_range(READ, ubuf, size, &iov, &msg.msg_iter);
+	err = import_single_range(ITER_DEST, ubuf, size, &iov, &msg.msg_iter);
 	if (unlikely(err))
 		return err;
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
@@ -2417,7 +2417,7 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
 	if (err)
 		return err;
 
-	err = import_iovec(save_addr ? READ : WRITE,
+	err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
 			    msg.msg_iov, msg.msg_iovlen,
 			    UIO_FASTIOV, iov, &kmsg->msg_iter);
 	return err < 0 ? err : 0;
diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 71ba4cf513bc..1b2b84feeec6 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -214,14 +214,14 @@ static inline int xprt_sendmsg(struct socket *sock, struct msghdr *msg,
 static int xprt_send_kvec(struct socket *sock, struct msghdr *msg,
 			  struct kvec *vec, size_t seek)
 {
-	iov_iter_kvec(&msg->msg_iter, WRITE, vec, 1, vec->iov_len);
+	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, 1, vec->iov_len);
 	return xprt_sendmsg(sock, msg, seek);
 }
 
 static int xprt_send_pagedata(struct socket *sock, struct msghdr *msg,
 			      struct xdr_buf *xdr, size_t base)
 {
-	iov_iter_bvec(&msg->msg_iter, WRITE, xdr->bvec, xdr_buf_pagecount(xdr),
+	iov_iter_bvec(&msg->msg_iter, ITER_SOURCE, xdr->bvec, xdr_buf_pagecount(xdr),
 		      xdr->page_len + xdr->page_base);
 	return xprt_sendmsg(sock, msg, base + xdr->page_base);
 }
@@ -244,7 +244,7 @@ static int xprt_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
 	};
 	size_t len = iov[0].iov_len + iov[1].iov_len;
 
-	iov_iter_kvec(&msg->msg_iter, WRITE, iov, 2, len);
+	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, iov, 2, len);
 	return xprt_sendmsg(sock, msg, base);
 }
 
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 2fc98fea59b4..015714398007 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -260,7 +260,7 @@ static ssize_t svc_tcp_read_msg(struct svc_rqst *rqstp, size_t buflen,
 	rqstp->rq_respages = &rqstp->rq_pages[i];
 	rqstp->rq_next_page = rqstp->rq_respages + 1;
 
-	iov_iter_bvec(&msg.msg_iter, READ, bvec, i, buflen);
+	iov_iter_bvec(&msg.msg_iter, ITER_DEST, bvec, i, buflen);
 	if (seek) {
 		iov_iter_advance(&msg.msg_iter, seek);
 		buflen -= seek;
@@ -874,7 +874,7 @@ static ssize_t svc_tcp_read_marker(struct svc_sock *svsk,
 		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
 		iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen;
 		iov.iov_len  = want;
-		iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, want);
+		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, want);
 		len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
 		if (len < 0)
 			return len;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 915b9902f673..b3ab6d9d752e 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -364,7 +364,7 @@ static ssize_t
 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
 		struct kvec *kvec, size_t count, size_t seek)
 {
-	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
+	iov_iter_kvec(&msg->msg_iter, ITER_DEST, kvec, 1, count);
 	return xs_sock_recvmsg(sock, msg, flags, seek);
 }
 
@@ -373,7 +373,7 @@ xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
 		struct bio_vec *bvec, unsigned long nr, size_t count,
 		size_t seek)
 {
-	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
+	iov_iter_bvec(&msg->msg_iter, ITER_DEST, bvec, nr, count);
 	return xs_sock_recvmsg(sock, msg, flags, seek);
 }
 
@@ -381,7 +381,7 @@ static ssize_t
 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
 		size_t count)
 {
-	iov_iter_discard(&msg->msg_iter, READ, count);
+	iov_iter_discard(&msg->msg_iter, ITER_DEST, count);
 	return sock_recvmsg(sock, msg, flags);
 }
 
diff --git a/net/tipc/topsrv.c b/net/tipc/topsrv.c
index d92ec92f0b71..d7166d84a7b2 100644
--- a/net/tipc/topsrv.c
+++ b/net/tipc/topsrv.c
@@ -394,7 +394,7 @@ static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
 	iov.iov_base = &s;
 	iov.iov_len = sizeof(s);
 	msg.msg_name = NULL;
-	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, iov.iov_len);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, iov.iov_len);
 	ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
 	if (ret == -EWOULDBLOCK)
 		return -EWOULDBLOCK;
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index a03d66046ca3..6c593788dc25 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -620,7 +620,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
 	kaddr = kmap(page);
 	iov.iov_base = kaddr + offset;
 	iov.iov_len = size;
-	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
+	iov_iter_kvec(&msg_iter, ITER_SOURCE, &iov, 1, size);
 	iter_offset.msg_iter = &msg_iter;
 	rc = tls_push_data(sk, iter_offset, size, flags, TLS_RECORD_TYPE_DATA,
 			   NULL);
@@ -697,7 +697,7 @@ static int tls_device_push_pending_record(struct sock *sk, int flags)
 	union tls_iter_offset iter;
 	struct iov_iter msg_iter;
 
-	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
+	iov_iter_kvec(&msg_iter, ITER_SOURCE, NULL, 0, 0);
 	iter.msg_iter = &msg_iter;
 	return tls_push_data(sk, iter, 0, flags, TLS_RECORD_TYPE_DATA, NULL);
 }
diff --git a/net/xfrm/espintcp.c b/net/xfrm/espintcp.c
index 29a540dcb5a7..d6fece1ed982 100644
--- a/net/xfrm/espintcp.c
+++ b/net/xfrm/espintcp.c
@@ -354,7 +354,7 @@ static int espintcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	*((__be16 *)buf) = cpu_to_be16(msglen);
 	pfx_iov.iov_base = buf;
 	pfx_iov.iov_len = sizeof(buf);
-	iov_iter_kvec(&pfx_iter, WRITE, &pfx_iov, 1, pfx_iov.iov_len);
+	iov_iter_kvec(&pfx_iter, ITER_SOURCE, &pfx_iov, 1, pfx_iov.iov_len);
 
 	err = sk_msg_memcopy_from_iter(sk, &pfx_iter, &emsg->skmsg,
 				       pfx_iov.iov_len);