use less confusing names for iov_iter direction initializers

[ Upstream commit de4eda9 ]

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>
Stable-dep-of: 6dd88fd ("vhost-scsi: unbreak any layout for response")
Signed-off-by: Sasha Levin <sashal@kernel.org>

arch/s390/kernel/crash_dump.c

@@ -153,7 +153,7 @@ int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
 
 	kvec.iov_base = dst;
 	kvec.iov_len = count;
-	iov_iter_kvec(&iter, READ, &kvec, 1, count);
+	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
 	if (copy_oldmem_iter(&iter, src, count) < count)
 		return -EFAULT;
 	return 0;

arch/s390/mm/maccess.c

@@ -128,7 +128,7 @@ int memcpy_real(void *dest, unsigned long src, size_t count)
 
 	kvec.iov_base = dest;
 	kvec.iov_len = count;
-	iov_iter_kvec(&iter, READ, &kvec, 1, count);
+	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
 	if (memcpy_real_iter(&iter, src, count) < count)
 		return -EFAULT;
 	return 0;

arch/x86/kernel/cpu/microcode/intel.c

@@ -902,7 +902,7 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device,
 
 	kvec.iov_base = (void *)firmware->data;
 	kvec.iov_len = firmware->size;
-	iov_iter_kvec(&iter, WRITE, &kvec, 1, firmware->size);
+	iov_iter_kvec(&iter, ITER_SOURCE, &kvec, 1, firmware->size);
 	ret = generic_load_microcode(cpu, &iter);
 
 	release_firmware(firmware);

arch/x86/kernel/crash_dump_64.c

@@ -57,7 +57,7 @@ ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
 	struct kvec kvec = { .iov_base = buf, .iov_len = count };
 	struct iov_iter iter;
 
-	iov_iter_kvec(&iter, READ, &kvec, 1, count);
+	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
 
 	return read_from_oldmem(&iter, count, ppos,
 				cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT));

crypto/testmgr.c

@@ -766,7 +766,7 @@ static int build_cipher_test_sglists(struct cipher_test_sglists *tsgls,
 	struct iov_iter input;
 	int err;
 
-	iov_iter_kvec(&input, WRITE, inputs, nr_inputs, src_total_len);
+	iov_iter_kvec(&input, ITER_SOURCE, inputs, nr_inputs, src_total_len);
 	err = build_test_sglist(&tsgls->src, cfg->src_divs, alignmask,
 				cfg->inplace_mode != OUT_OF_PLACE ?
 					max(dst_total_len, src_total_len) :
@@ -1180,7 +1180,7 @@ static int build_hash_sglist(struct test_sglist *tsgl,
 
 	kv.iov_base = (void *)vec->plaintext;
 	kv.iov_len = vec->psize;
-	iov_iter_kvec(&input, WRITE, &kv, 1, vec->psize);
+	iov_iter_kvec(&input, ITER_SOURCE, &kv, 1, vec->psize);
 	return build_test_sglist(tsgl, cfg->src_divs, alignmask, vec->psize,
 				 &input, divs);
 }

drivers/acpi/pfr_update.c

@@ -455,7 +455,7 @@ static ssize_t pfru_write(struct file *file, const char __user *buf,
 
 	iov.iov_base = (void __user *)buf;
 	iov.iov_len = len;
-	iov_iter_init(&iter, WRITE, &iov, 1, len);
+	iov_iter_init(&iter, ITER_SOURCE, &iov, 1, len);
 
 	/* map the communication buffer */
 	phy_addr = (phys_addr_t)((buf_info.addr_hi << 32) | buf_info.addr_lo);

drivers/block/drbd/drbd_main.c

@@ -1816,7 +1816,7 @@ int drbd_send(struct drbd_connection *connection, struct socket *sock,
 
 	/* THINK  if (signal_pending) return ... ? */
 
-	iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, size);
 
 	if (sock == connection->data.socket) {
 		rcu_read_lock();

drivers/block/drbd/drbd_receiver.c

@@ -507,7 +507,7 @@ static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flag
 	struct msghdr msg = {
 		.msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL)
 	};
-	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, size);
 	return sock_recvmsg(sock, &msg, msg.msg_flags);
 }
 

drivers/block/loop.c

@@ -243,7 +243,7 @@ static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos)
 	struct iov_iter i;
 	ssize_t bw;
 
-	iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len);
+	iov_iter_bvec(&i, ITER_SOURCE, bvec, 1, bvec->bv_len);
 
 	file_start_write(file);
 	bw = vfs_iter_write(file, &i, ppos, 0);
@@ -286,7 +286,7 @@ static int lo_read_simple(struct loop_device *lo, struct request *rq,
 	ssize_t len;
 
 	rq_for_each_segment(bvec, rq, iter) {
-		iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len);
+		iov_iter_bvec(&i, ITER_DEST, &bvec, 1, bvec.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0)
 			return len;
@@ -392,7 +392,7 @@ static void lo_rw_aio_complete(struct kiocb *iocb, long ret)
 }
 
 static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
-		     loff_t pos, bool rw)
+		     loff_t pos, int rw)
 {
 	struct iov_iter iter;
 	struct req_iterator rq_iter;
@@ -448,7 +448,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
 	cmd->iocb.ki_flags = IOCB_DIRECT;
 	cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0);
 
-	if (rw == WRITE)
+	if (rw == ITER_SOURCE)
 		ret = call_write_iter(file, &cmd->iocb, &iter);
 	else
 		ret = call_read_iter(file, &cmd->iocb, &iter);
@@ -490,12 +490,12 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 		return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE);
 	case REQ_OP_WRITE:
 		if (cmd->use_aio)
-			return lo_rw_aio(lo, cmd, pos, WRITE);
+			return lo_rw_aio(lo, cmd, pos, ITER_SOURCE);
 		else
 			return lo_write_simple(lo, rq, pos);
 	case REQ_OP_READ:
 		if (cmd->use_aio)
-			return lo_rw_aio(lo, cmd, pos, READ);
+			return lo_rw_aio(lo, cmd, pos, ITER_DEST);
 		else
 			return lo_read_simple(lo, rq, pos);
 	default:

drivers/block/nbd.c

@@ -563,7 +563,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
 	u32 nbd_cmd_flags = 0;
 	int sent = nsock->sent, skip = 0;
 
-	iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
+	iov_iter_kvec(&from, ITER_SOURCE, &iov, 1, sizeof(request));
 
 	type = req_to_nbd_cmd_type(req);
 	if (type == U32_MAX)
@@ -649,7 +649,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
 
 			dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
 				req, bvec.bv_len);
-			iov_iter_bvec(&from, WRITE, &bvec, 1, bvec.bv_len);
+			iov_iter_bvec(&from, ITER_SOURCE, &bvec, 1, bvec.bv_len);
 			if (skip) {
 				if (skip >= iov_iter_count(&from)) {
 					skip -= iov_iter_count(&from);
@@ -701,7 +701,7 @@ static int nbd_read_reply(struct nbd_device *nbd, int index,
 	int result;
 
 	reply->magic = 0;
-	iov_iter_kvec(&to, READ, &iov, 1, sizeof(*reply));
+	iov_iter_kvec(&to, ITER_DEST, &iov, 1, sizeof(*reply));
 	result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
 	if (result < 0) {
 		if (!nbd_disconnected(nbd->config))
@@ -790,7 +790,7 @@ static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index,
 		struct iov_iter to;
 
 		rq_for_each_segment(bvec, req, iter) {
-			iov_iter_bvec(&to, READ, &bvec, 1, bvec.bv_len);
+			iov_iter_bvec(&to, ITER_DEST, &bvec, 1, bvec.bv_len);
 			result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
 			if (result < 0) {
 				dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
@@ -1267,7 +1267,7 @@ static void send_disconnects(struct nbd_device *nbd)
 	for (i = 0; i < config->num_connections; i++) {
 		struct nbd_sock *nsock = config->socks[i];
 
-		iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
+		iov_iter_kvec(&from, ITER_SOURCE, &iov, 1, sizeof(request));
 		mutex_lock(&nsock->tx_lock);
 		ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
 		if (ret < 0)

drivers/char/random.c

@@ -1329,7 +1329,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, ubuf, size_t, len, unsigned int, flags
 			return ret;
 	}
 
-	ret = import_single_range(READ, ubuf, len, &iov, &iter);
+	ret = import_single_range(ITER_DEST, ubuf, len, &iov, &iter);
 	if (unlikely(ret))
 		return ret;
 	return get_random_bytes_user(&iter);
@@ -1447,7 +1447,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 			return -EINVAL;
 		if (get_user(len, p++))
 			return -EFAULT;
-		ret = import_single_range(WRITE, p, len, &iov, &iter);
+		ret = import_single_range(ITER_SOURCE, p, len, &iov, &iter);
 		if (unlikely(ret))
 			return ret;
 		ret = write_pool_user(&iter);

drivers/fsi/fsi-sbefifo.c

@@ -659,7 +659,7 @@ static void sbefifo_collect_async_ffdc(struct sbefifo *sbefifo)
 	}
         ffdc_iov.iov_base = ffdc;
 	ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE;
-        iov_iter_kvec(&ffdc_iter, READ, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE);
+        iov_iter_kvec(&ffdc_iter, ITER_DEST, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE);
 	cmd[0] = cpu_to_be32(2);
 	cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_SBE_FFDC);
 	rc = sbefifo_do_command(sbefifo, cmd, 2, &ffdc_iter);
@@ -756,7 +756,7 @@ int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len,
 	rbytes = (*resp_len) * sizeof(__be32);
 	resp_iov.iov_base = response;
 	resp_iov.iov_len = rbytes;
-        iov_iter_kvec(&resp_iter, READ, &resp_iov, 1, rbytes);
+        iov_iter_kvec(&resp_iter, ITER_DEST, &resp_iov, 1, rbytes);
 
 	/* Perform the command */
 	rc = mutex_lock_interruptible(&sbefifo->lock);
@@ -839,7 +839,7 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
 	/* Prepare iov iterator */
 	resp_iov.iov_base = buf;
 	resp_iov.iov_len = len;
-	iov_iter_init(&resp_iter, READ, &resp_iov, 1, len);
+	iov_iter_init(&resp_iter, ITER_DEST, &resp_iov, 1, len);
 
 	/* Perform the command */
 	rc = mutex_lock_interruptible(&sbefifo->lock);

drivers/infiniband/ulp/rtrs/rtrs-clt.c

@@ -966,7 +966,7 @@ static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
 	refcount_set(&req->ref, 1);
 	req->mp_policy = clt_path->clt->mp_policy;
 
-	iov_iter_kvec(&iter, WRITE, vec, 1, usr_len);
+	iov_iter_kvec(&iter, ITER_SOURCE, vec, 1, usr_len);
 	len = _copy_from_iter(req->iu->buf, usr_len, &iter);
 	WARN_ON(len != usr_len);
 

drivers/isdn/mISDN/l1oip_core.c

@@ -706,7 +706,7 @@ l1oip_socket_thread(void *data)
 		printk(KERN_DEBUG "%s: socket created and open\n",
 		       __func__);
 	while (!signal_pending(current)) {
-		iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, recvbuf_size);
+		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, recvbuf_size);
 		recvlen = sock_recvmsg(socket, &msg, 0);
 		if (recvlen > 0) {
 			l1oip_socket_parse(hc, &sin_rx, recvbuf, recvlen);

drivers/misc/vmw_vmci/vmci_queue_pair.c

@@ -3044,7 +3044,7 @@ ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair,
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&from, WRITE, &v, 1, buf_size);
+	iov_iter_kvec(&from, ITER_SOURCE, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
@@ -3088,7 +3088,7 @@ ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair,
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&to, READ, &v, 1, buf_size);
+	iov_iter_kvec(&to, ITER_DEST, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
@@ -3133,7 +3133,7 @@ ssize_t vmci_qpair_peek(struct vmci_qp *qpair,
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&to, READ, &v, 1, buf_size);
+	iov_iter_kvec(&to, ITER_DEST, &v, 1, buf_size);
 
 	qp_lock(qpair);
 

drivers/net/ppp/ppp_generic.c

@@ -480,7 +480,7 @@ static ssize_t ppp_read(struct file *file, char __user *buf,
 	ret = -EFAULT;
 	iov.iov_base = buf;
 	iov.iov_len = count;
-	iov_iter_init(&to, READ, &iov, 1, count);
+	iov_iter_init(&to, ITER_DEST, &iov, 1, count);
 	if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
 		goto outf;
 	ret = skb->len;

drivers/nvme/host/tcp.c

@@ -301,7 +301,7 @@ static inline void nvme_tcp_advance_req(struct nvme_tcp_request *req,
 	if (!iov_iter_count(&req->iter) &&
 	    req->data_sent < req->data_len) {
 		req->curr_bio = req->curr_bio->bi_next;
-		nvme_tcp_init_iter(req, WRITE);
+		nvme_tcp_init_iter(req, ITER_SOURCE);
 	}
 }
 
@@ -781,7 +781,7 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 				nvme_tcp_init_recv_ctx(queue);
 				return -EIO;
 			}
-			nvme_tcp_init_iter(req, READ);
+			nvme_tcp_init_iter(req, ITER_DEST);
 		}
 
 		/* we can read only from what is left in this bio */

drivers/nvme/target/io-cmd-file.c

@@ -92,10 +92,10 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
 		if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
 			ki_flags |= IOCB_DSYNC;
 		call_iter = req->ns->file->f_op->write_iter;
-		rw = WRITE;
+		rw = ITER_SOURCE;
 	} else {
 		call_iter = req->ns->file->f_op->read_iter;
-		rw = READ;
+		rw = ITER_DEST;
 	}
 
 	iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);

drivers/nvme/target/tcp.c

@@ -331,7 +331,7 @@ static void nvmet_tcp_build_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 		sg_offset = 0;
 	}
 
-	iov_iter_bvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
+	iov_iter_bvec(&cmd->recv_msg.msg_iter, ITER_DEST, cmd->iov,
 		      nr_pages, cmd->pdu_len);
 }
 

drivers/s390/char/zcore.c

@@ -103,7 +103,7 @@ static inline int memcpy_hsa_kernel(void *dst, unsigned long src, size_t count)
 
 	kvec.iov_base = dst;
 	kvec.iov_len = count;
-	iov_iter_kvec(&iter, READ, &kvec, 1, count);
+	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
 	if (memcpy_hsa_iter(&iter, src, count) < count)
 		return -EIO;
 	return 0;

drivers/scsi/sg.c

@@ -1726,7 +1726,7 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
 	struct request_queue *q = sfp->parentdp->device->request_queue;
 	struct rq_map_data *md, map_data;
-	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
+	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? ITER_SOURCE : ITER_DEST;
 	struct scsi_cmnd *scmd;
 
 	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,

drivers/target/iscsi/iscsi_target_util.c

@@ -1225,7 +1225,7 @@ int rx_data(
 		return -1;
 
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ, iov, iov_count, data);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, iov, iov_count, data);
 
 	while (msg_data_left(&msg)) {
 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
@@ -1261,7 +1261,7 @@ int tx_data(
 
 	memset(&msg, 0, sizeof(struct msghdr));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE, iov, iov_count, data);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, iov_count, data);
 
 	while (msg_data_left(&msg)) {
 		int tx_loop = sock_sendmsg(conn->sock, &msg);

drivers/target/target_core_file.c

@@ -473,7 +473,7 @@ fd_execute_write_same(struct se_cmd *cmd)
 		len += se_dev->dev_attrib.block_size;
 	}
 
-	iov_iter_bvec(&iter, WRITE, bvec, nolb, len);
+	iov_iter_bvec(&iter, ITER_SOURCE, bvec, nolb, len);
 	ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 
 	kfree(bvec);

drivers/usb/usbip/usbip_common.c

@@ -309,7 +309,7 @@ int usbip_recv(struct socket *sock, void *buf, int size)
 	if (!sock || !buf || !size)
 		return -EINVAL;
 
-	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, size);
 
 	usbip_dbg_xmit("enter\n");
 

drivers/vhost/net.c

@@ -611,7 +611,7 @@ static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
 	/* Skip header. TODO: support TSO. */
 	size_t len = iov_length(vq->iov, out);
 
-	iov_iter_init(iter, WRITE, vq->iov, out, len);
+	iov_iter_init(iter, ITER_SOURCE, vq->iov, out, len);
 	iov_iter_advance(iter, hdr_size);
 
 	return iov_iter_count(iter);
@@ -1184,14 +1184,14 @@ static void handle_rx(struct vhost_net *net)
 			msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
 		/* On overrun, truncate and discard */
 		if (unlikely(headcount > UIO_MAXIOV)) {
-			iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
+			iov_iter_init(&msg.msg_iter, ITER_DEST, vq->iov, 1, 1);
 			err = sock->ops->recvmsg(sock, &msg,
 						 1, MSG_DONTWAIT | MSG_TRUNC);
 			pr_debug("Discarded rx packet: len %zd\n", sock_len);
 			continue;
 		}
 		/* We don't need to be notified again. */
-		iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len);
+		iov_iter_init(&msg.msg_iter, ITER_DEST, vq->iov, in, vhost_len);
 		fixup = msg.msg_iter;
 		if (unlikely((vhost_hlen))) {
 			/* We will supply the header ourselves