iov_iter: Separate type from direction and use accessor functions

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.

Signed-off-by: David Howells <[e-mail]>

drivers/block/drbd/drbd_main.c

···
 
 	/* THINK  if (signal_pending) return ... ? */
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size);
 
 	if (sock == connection->data.socket) {
 		rcu_read_lock();

drivers/block/drbd/drbd_receiver.c

···
 	struct msghdr msg = {
 		.msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL)
 	};
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, size);
 	return sock_recvmsg(sock, &msg, msg.msg_flags);
 }
 

drivers/block/loop.c

···
 	struct iov_iter i;
 	ssize_t bw;
 
-	iov_iter_bvec(&i, ITER_BVEC | WRITE, bvec, 1, bvec->bv_len);
+	iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len);
 
 	file_start_write(file);
 	bw = vfs_iter_write(file, &i, ppos, 0);
···
 	ssize_t len;
 
 	rq_for_each_segment(bvec, rq, iter) {
-		iov_iter_bvec(&i, ITER_BVEC, &bvec, 1, bvec.bv_len);
+		iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0)
 			return len;
···
 		b.bv_offset = 0;
 		b.bv_len = bvec.bv_len;
 
-		iov_iter_bvec(&i, ITER_BVEC, &b, 1, b.bv_len);
+		iov_iter_bvec(&i, READ, &b, 1, b.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0) {
 			ret = len;
···
 	}
 	atomic_set(&cmd->ref, 2);
 
-	iov_iter_bvec(&iter, ITER_BVEC | rw, bvec,
-		      segments, blk_rq_bytes(rq));
+	iov_iter_bvec(&iter, rw, bvec, segments, blk_rq_bytes(rq));
 	iter.iov_offset = offset;
 
 	cmd->iocb.ki_pos = pos;

drivers/block/nbd.c

···
 	u32 nbd_cmd_flags = 0;
 	int sent = nsock->sent, skip = 0;
 
-	iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
+	iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
 
 	switch (req_op(req)) {
 	case REQ_OP_DISCARD:
···
 
 			dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
 				req, bvec.bv_len);
-			iov_iter_bvec(&from, ITER_BVEC | WRITE,
-				      &bvec, 1, bvec.bv_len);
+			iov_iter_bvec(&from, WRITE, &bvec, 1, bvec.bv_len);
 			if (skip) {
 				if (skip >= iov_iter_count(&from)) {
 					skip -= iov_iter_count(&from);
···
 	int ret = 0;
 
 	reply.magic = 0;
-	iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply));
+	iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply));
 	result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
 	if (result <= 0) {
 		if (!nbd_disconnected(config))
···
 		struct bio_vec bvec;
 
 		rq_for_each_segment(bvec, req, iter) {
-			iov_iter_bvec(&to, ITER_BVEC | READ,
-				      &bvec, 1, bvec.bv_len);
+			iov_iter_bvec(&to, READ, &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",
···
 	for (i = 0; i < config->num_connections; i++) {
 		struct nbd_sock *nsock = config->socks[i];
 
-		iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
+		iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
 		mutex_lock(&nsock->tx_lock);
 		ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
 		if (ret <= 0)

drivers/fsi/fsi-sbefifo.c

···
 	}
         ffdc_iov.iov_base = ffdc;
 	ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE;
-        iov_iter_kvec(&ffdc_iter, WRITE | ITER_KVEC, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE);
+        iov_iter_kvec(&ffdc_iter, WRITE, &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);
···
 	rbytes = (*resp_len) * sizeof(__be32);
 	resp_iov.iov_base = response;
 	resp_iov.iov_len = rbytes;
-        iov_iter_kvec(&resp_iter, WRITE | ITER_KVEC, &resp_iov, 1, rbytes);
+        iov_iter_kvec(&resp_iter, WRITE, &resp_iov, 1, rbytes);
 
 	/* Perform the command */
 	mutex_lock(&sbefifo->lock);

drivers/isdn/mISDN/l1oip_core.c

···
 		printk(KERN_DEBUG "%s: socket created and open\n",
 		       __func__);
 	while (!signal_pending(current)) {
-		iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1,
-				recvbuf_size);
+		iov_iter_kvec(&msg.msg_iter, READ, &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

···
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&from, WRITE | ITER_KVEC, &v, 1, buf_size);
+	iov_iter_kvec(&from, WRITE, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
···
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &v, 1, buf_size);
+	iov_iter_kvec(&to, READ, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
···
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &v, 1, buf_size);
+	iov_iter_kvec(&to, READ, &v, 1, buf_size);
 
 	qp_lock(qpair);
 

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

···
 		rw = READ;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC | rw, req->f.bvec, nr_segs, count);
+	iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);
 
 	iocb->ki_pos = pos;
 	iocb->ki_filp = req->ns->file;

drivers/target/iscsi/iscsi_target_util.c

···
 		return -1;
 
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
-		      count->iov, count->iov_count, data);
+	iov_iter_kvec(&msg.msg_iter, READ, count->iov, count->iov_count, data);
 
 	while (msg_data_left(&msg)) {
 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
···
 
 	memset(&msg, 0, sizeof(struct msghdr));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC,
-		      iov, iov_count, data);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, iov_count, data);
 
 	while (msg_data_left(&msg)) {
 		int tx_loop = sock_sendmsg(conn->sock, &msg);

drivers/target/target_core_file.c

···
 		len += sg->length;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC | is_write, bvec, sgl_nents, len);
+	iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
 
 	aio_cmd->cmd = cmd;
 	aio_cmd->len = len;
···
 		len += sg->length;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
+	iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
 	if (is_write)
 		ret = vfs_iter_write(fd, &iter, &pos, 0);
 	else
···
 		len += se_dev->dev_attrib.block_size;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
+	iov_iter_bvec(&iter, READ, bvec, nolb, len);
 	ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 
 	kfree(bvec);

drivers/usb/usbip/usbip_common.c

···
 	if (!sock || !buf || !size)
 		return -EINVAL;
 
-	iov_iter_kvec(&msg.msg_iter, READ|ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, size);
 
 	usbip_dbg_xmit("enter\n");
 

drivers/xen/pvcalls-back.c

···
 	if (masked_prod < masked_cons) {
 		vec[0].iov_base = data->in + masked_prod;
 		vec[0].iov_len = wanted;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|WRITE, vec, 1, wanted);
+		iov_iter_kvec(&msg.msg_iter, WRITE, vec, 1, wanted);
 	} else {
 		vec[0].iov_base = data->in + masked_prod;
 		vec[0].iov_len = array_size - masked_prod;
 		vec[1].iov_base = data->in;
 		vec[1].iov_len = wanted - vec[0].iov_len;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|WRITE, vec, 2, wanted);
+		iov_iter_kvec(&msg.msg_iter, WRITE, vec, 2, wanted);
 	}
 
 	atomic_set(&map->read, 0);
···
 	if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) {
 		vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
 		vec[0].iov_len = size;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|READ, vec, 1, size);
+		iov_iter_kvec(&msg.msg_iter, READ, vec, 1, size);
 	} else {
 		vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
 		vec[0].iov_len = array_size - pvcalls_mask(cons, array_size);
 		vec[1].iov_base = data->out;
 		vec[1].iov_len = size - vec[0].iov_len;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|READ, vec, 2, size);
+		iov_iter_kvec(&msg.msg_iter, READ, vec, 2, size);
 	}
 
 	atomic_set(&map->write, 0);

fs/9p/vfs_addr.c

···
 	if (retval == 0)
 		return retval;
 
-	iov_iter_bvec(&to, ITER_BVEC | READ, &bvec, 1, PAGE_SIZE);
+	iov_iter_bvec(&to, READ, &bvec, 1, PAGE_SIZE);
 
 	retval = p9_client_read(fid, page_offset(page), &to, &err);
 	if (err) {
···
 	bvec.bv_page = page;
 	bvec.bv_offset = 0;
 	bvec.bv_len = len;
-	iov_iter_bvec(&from, ITER_BVEC | WRITE, &bvec, 1, len);
+	iov_iter_bvec(&from, WRITE, &bvec, 1, len);
 
 	/* We should have writeback_fid always set */
 	BUG_ON(!v9inode->writeback_fid);

fs/9p/vfs_dir.c

···
 		if (rdir->tail == rdir->head) {
 			struct iov_iter to;
 			int n;
-			iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
+			iov_iter_kvec(&to, READ, &kvec, 1, buflen);
 			n = p9_client_read(file->private_data, ctx->pos, &to,
 					   &err);
 			if (err)

fs/9p/xattr.c

···
 	struct iov_iter to;
 	int err;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buffer_size);
+	iov_iter_kvec(&to, READ, &kvec, 1, buffer_size);
 
 	attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
 	if (IS_ERR(attr_fid)) {
···
 	struct iov_iter from;
 	int retval, err;
 
-	iov_iter_kvec(&from, WRITE | ITER_KVEC, &kvec, 1, value_len);
+	iov_iter_kvec(&from, WRITE, &kvec, 1, value_len);
 
 	p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n",
 		 name, value_len, flags);

fs/afs/rxrpc.c

···
 		offset = 0;
 	}
 
-	iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
+	iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
 }
 
 /*
···
 
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
-		      call->request_size);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
···
 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
 					RX_USER_ABORT, ret, "KSD");
 	} else {
-		iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, NULL, 0, 0);
+		iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 		rxrpc_kernel_recv_data(call->net->socket, rxcall,
 				       &msg.msg_iter, false,
 				       &call->abort_code, &call->service_id);
···
 		if (state == AFS_CALL_SV_AWAIT_ACK) {
 			struct iov_iter iter;
 
-			iov_iter_kvec(&iter, READ | ITER_KVEC, NULL, 0, 0);
+			iov_iter_kvec(&iter, READ, NULL, 0, 0);
 			ret = rxrpc_kernel_recv_data(call->net->socket,
 						     call->rxcall, &iter, false,
 						     &remote_abort,
···
 
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
+	iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= 0;
···
 	iov[0].iov_len		= len;
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= 0;
···
 
 	iov.iov_base = buf + call->offset;
 	iov.iov_len = count - call->offset;
-	iov_iter_kvec(&iter, ITER_KVEC | READ, &iov, 1, count - call->offset);
+	iov_iter_kvec(&iter, READ, &iov, 1, count - call->offset);
 
 	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, &iter,
 				     want_more, &remote_abort,

fs/ceph/file.c

···
 				aio_req->total_len = rc + zlen;
 			}
 
-			iov_iter_bvec(&i, ITER_BVEC, osd_data->bvec_pos.bvecs,
+			iov_iter_bvec(&i, READ, osd_data->bvec_pos.bvecs,
 				      osd_data->num_bvecs,
 				      osd_data->bvec_pos.iter.bi_size);
 			iov_iter_advance(&i, rc);
···
 				int zlen = min_t(size_t, len - ret,
 						 size - pos - ret);
 
-				iov_iter_bvec(&i, ITER_BVEC, bvecs, num_pages,
-					      len);
+				iov_iter_bvec(&i, READ, bvecs, num_pages, len);
 				iov_iter_advance(&i, ret);
 				iov_iter_zero(zlen, &i);
 				ret += zlen;

fs/cifs/connect.c

···
 {
 	struct msghdr smb_msg;
 	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
-	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);
+	iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 
 	return cifs_readv_from_socket(server, &smb_msg);
 }
···
 	struct msghdr smb_msg;
 	struct bio_vec bv = {
 		.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
-	iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
+	iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 	return cifs_readv_from_socket(server, &smb_msg);
 }
 

fs/cifs/misc.c

···
 	ctx->bv = bv;
 	ctx->len = saved_len - count;
 	ctx->npages = npages;
-	iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
+	iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
 	return 0;
 }
 

fs/cifs/smb2ops.c

···
 			return 0;
 		}
 
-		iov_iter_bvec(&iter, WRITE | ITER_BVEC, bvec, npages, data_len);
+		iov_iter_bvec(&iter, WRITE, bvec, npages, data_len);
 	} else if (buf_len >= data_offset + data_len) {
 		/* read response payload is in buf */
 		WARN_ONCE(npages > 0, "read data can be either in buf or in pages");
 		iov.iov_base = buf + data_offset;
 		iov.iov_len = data_len;
-		iov_iter_kvec(&iter, WRITE | ITER_KVEC, &iov, 1, data_len);
+		iov_iter_kvec(&iter, WRITE, &iov, 1, data_len);
 	} else {
 		/* read response payload cannot be in both buf and pages */
 		WARN_ONCE(1, "buf can not contain only a part of read data");

fs/cifs/transport.c

···
 			.iov_base = &rfc1002_marker,
 			.iov_len  = 4
 		};
-		iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, &hiov,
-			      1, 4);
+		iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
 		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
 			goto uncork;
···
 			size += iov[i].iov_len;
 		}
 
-		iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC,
-			      iov, n_vec, size);
+		iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
 
 		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
···
 			rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
 					     &bvec.bv_offset);
 
-			iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
+			iov_iter_bvec(&smb_msg.msg_iter, WRITE,
 				      &bvec, 1, bvec.bv_len);
 			rc = smb_send_kvec(server, &smb_msg, &sent);
 			if (rc < 0)

fs/dlm/lowcomms.c

···
 		nvec = 2;
 	}
 	len = iov[0].iov_len + iov[1].iov_len;
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, iov, nvec, len);
+	iov_iter_kvec(&msg.msg_iter, READ, iov, nvec, len);
 
 	r = ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
 	if (ret <= 0)

fs/nfsd/vfs.c

···
 	int host_err;
 
 	trace_nfsd_read_vector(rqstp, fhp, offset, *count);
-	iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
+	iov_iter_kvec(&iter, READ, vec, vlen, *count);
 	host_err = vfs_iter_read(file, &iter, &offset, 0);
 	return nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
 }
···
 	if (stable && !use_wgather)
 		flags |= RWF_SYNC;
 
-	iov_iter_kvec(&iter, WRITE | ITER_KVEC, vec, vlen, *cnt);
+	iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
 	host_err = vfs_iter_write(file, &iter, &pos, flags);
 	if (host_err < 0)
 		goto out_nfserr;

fs/ocfs2/cluster/tcp.c

···
 {
 	struct kvec vec = { .iov_len = len, .iov_base = data, };
 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, len);
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, len);
 	return sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 }
 

fs/orangefs/inode.c

···
 	struct iov_iter to;
 	struct bio_vec bv = {.bv_page = page, .bv_len = PAGE_SIZE};
 
-	iov_iter_bvec(&to, ITER_BVEC | READ, &bv, 1, PAGE_SIZE);
+	iov_iter_bvec(&to, READ, &bv, 1, PAGE_SIZE);
 
 	gossip_debug(GOSSIP_INODE_DEBUG,
 		    "orangefs_readpage called with page %p\n",

fs/splice.c

···
 	struct kiocb kiocb;
 	int idx, ret;
 
-	iov_iter_pipe(&to, ITER_PIPE | READ, pipe, len);
+	iov_iter_pipe(&to, READ, pipe, len);
 	idx = to.idx;
 	init_sync_kiocb(&kiocb, in);
 	kiocb.ki_pos = *ppos;
···
 	 */
 	offset = *ppos & ~PAGE_MASK;
 
-	iov_iter_pipe(&to, ITER_PIPE | READ, pipe, len + offset);
+	iov_iter_pipe(&to, READ, pipe, len + offset);
 
 	res = iov_iter_get_pages_alloc(&to, &pages, len + offset, &base);
 	if (res <= 0)
···
 			left -= this_len;
 		}
 
-		iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n,
-			      sd.total_len - left);
+		iov_iter_bvec(&from, WRITE, array, n, sd.total_len - left);
 		ret = vfs_iter_write(out, &from, &sd.pos, 0);
 		if (ret <= 0)
 			break;

include/linux/uio.h

···
 };
 
 struct iov_iter {
-	int type;
+	unsigned int type;
 	size_t iov_offset;
 	size_t count;
 	union {
···
 size_t iov_iter_zero(size_t bytes, struct iov_iter *);
 unsigned long iov_iter_alignment(const struct iov_iter *i);
 unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
-void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
+void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
 			unsigned long nr_segs, size_t count);
-void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
+void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec,
 			unsigned long nr_segs, size_t count);
-void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
+void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec,
 			unsigned long nr_segs, size_t count);
-void iov_iter_pipe(struct iov_iter *i, int direction, struct pipe_inode_info *pipe,
+void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
 			size_t count);
 ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
 			size_t maxsize, unsigned maxpages, size_t *start);

lib/iov_iter.c

···
 }
 EXPORT_SYMBOL(iov_iter_fault_in_readable);
 
-void iov_iter_init(struct iov_iter *i, int direction,
+void iov_iter_init(struct iov_iter *i, unsigned int direction,
 			const struct iovec *iov, unsigned long nr_segs,
 			size_t count)
 {
+	WARN_ON(direction & ~(READ | WRITE));
+	direction &= READ | WRITE;
+
 	/* It will get better.  Eventually... */
 	if (uaccess_kernel()) {
-		direction |= ITER_KVEC;
-		i->type = direction;
+		i->type = ITER_KVEC | direction;
 		i->kvec = (struct kvec *)iov;
 	} else {
-		i->type = direction;
+		i->type = ITER_IOVEC | direction;
 		i->iov = iov;
 	}
 	i->nr_segs = nr_segs;
···
 }
 EXPORT_SYMBOL(iov_iter_single_seg_count);
 
-void iov_iter_kvec(struct iov_iter *i, int direction,
+void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
 			const struct kvec *kvec, unsigned long nr_segs,
 			size_t count)
 {
-	BUG_ON(!(direction & ITER_KVEC));
-	i->type = direction;
+	WARN_ON(direction & ~(READ | WRITE));
+	i->type = ITER_KVEC | (direction & (READ | WRITE));
 	i->kvec = kvec;
 	i->nr_segs = nr_segs;
 	i->iov_offset = 0;
···
 }
 EXPORT_SYMBOL(iov_iter_kvec);
 
-void iov_iter_bvec(struct iov_iter *i, int direction,
+void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
 			const struct bio_vec *bvec, unsigned long nr_segs,
 			size_t count)
 {
-	BUG_ON(!(direction & ITER_BVEC));
-	i->type = direction;
+	WARN_ON(direction & ~(READ | WRITE));
+	i->type = ITER_BVEC | (direction & (READ | WRITE));
 	i->bvec = bvec;
 	i->nr_segs = nr_segs;
 	i->iov_offset = 0;
···
 }
 EXPORT_SYMBOL(iov_iter_bvec);
 
-void iov_iter_pipe(struct iov_iter *i, int direction,
+void iov_iter_pipe(struct iov_iter *i, unsigned int direction,
 			struct pipe_inode_info *pipe,
 			size_t count)
 {
-	BUG_ON(direction != ITER_PIPE);
+	BUG_ON(direction != READ);
 	WARN_ON(pipe->nrbufs == pipe->buffers);
-	i->type = direction;
+	i->type = ITER_PIPE | READ;
 	i->pipe = pipe;
 	i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
 	i->iov_offset = 0;

mm/page_io.c

···
 		};
 		struct iov_iter from;
 
-		iov_iter_bvec(&from, ITER_BVEC | WRITE, &bv, 1, PAGE_SIZE);
+		iov_iter_bvec(&from, WRITE, &bv, 1, PAGE_SIZE);
 		init_sync_kiocb(&kiocb, swap_file);
 		kiocb.ki_pos = page_file_offset(page);
 

net/9p/client.c

···
 	struct kvec kv = {.iov_base = data, .iov_len = count};
 	struct iov_iter to;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
+	iov_iter_kvec(&to, READ, &kv, 1, count);
 
 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
 				fid->fid, (unsigned long long) offset, count);

net/bluetooth/6lowpan.c

···
 	iv.iov_len = skb->len;
 
 	memset(&msg, 0, sizeof(msg));
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
 
 	err = l2cap_chan_send(chan, &msg, skb->len);
 	if (err > 0) {

net/bluetooth/a2mp.c

···
 
 	memset(&msg, 0, sizeof(msg));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, total_len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, total_len);
 
 	l2cap_chan_send(chan, &msg, total_len);
 

net/bluetooth/smp.c

···
 
 	memset(&msg, 0, sizeof(msg));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len);
 
 	l2cap_chan_send(chan, &msg, 1 + len);
 

net/ceph/messenger.c

···
 	if (!buf)
 		msg.msg_flags |= MSG_TRUNC;
 
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, len);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, len);
 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
 	if (r == -EAGAIN)
 		r = 0;
···
 	int r;
 
 	BUG_ON(page_offset + length > PAGE_SIZE);
-	iov_iter_bvec(&msg.msg_iter, READ | ITER_BVEC, &bvec, 1, length);
+	iov_iter_bvec(&msg.msg_iter, READ, &bvec, 1, length);
 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
 	if (r == -EAGAIN)
 		r = 0;
···
 	else
 		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
 
-	iov_iter_bvec(&msg.msg_iter, WRITE | ITER_BVEC, &bvec, 1, size);
+	iov_iter_bvec(&msg.msg_iter, WRITE, &bvec, 1, size);
 	ret = sock_sendmsg(sock, &msg);
 	if (ret == -EAGAIN)
 		ret = 0;

net/netfilter/ipvs/ip_vs_sync.c

···
 	EnterFunction(7);
 
 	/* Receive a packet */
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, buflen);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, buflen);
 	len = sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 	if (len < 0)
 		return len;

net/smc/smc_clc.c

···
 	 */
 	krflags = MSG_PEEK | MSG_WAITALL;
 	smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1,
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
 			sizeof(struct smc_clc_msg_hdr));
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
 	if (signal_pending(current)) {
···
 
 	/* receive the complete CLC message */
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, datlen);
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
 	krflags = MSG_WAITALL;
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
 	if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {

net/socket.c

···
 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 | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
 	return sock_sendmsg(sock, msg);
 }
 EXPORT_SYMBOL(kernel_sendmsg);
···
 	if (!sock->ops->sendmsg_locked)
 		return sock_no_sendmsg_locked(sk, msg, size);
 
-	iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
 
 	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
 }
···
 	mm_segment_t oldfs = get_fs();
 	int result;
 
-	iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, READ, vec, num, size);
 	set_fs(KERNEL_DS);
 	result = sock_recvmsg(sock, msg, flags);
 	set_fs(oldfs);

net/sunrpc/svcsock.c

···
 	rqstp->rq_xprt_hlen = 0;
 
 	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, iov, nr, buflen);
+	iov_iter_kvec(&msg.msg_iter, READ, iov, nr, buflen);
 	len = sock_recvmsg(svsk->sk_sock, &msg, msg.msg_flags);
 	/* If we read a full record, then assume there may be more
 	 * data to read (stream based sockets only!)

net/tipc/topsrv.c

···
 	iov.iov_base = &s;
 	iov.iov_len = sizeof(s);
 	msg.msg_name = NULL;
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, iov.iov_len);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, iov.iov_len);
 	ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
 	if (ret == -EWOULDBLOCK)
 		return -EWOULDBLOCK;

net/tls/tls_device.c

···
 
 	iov.iov_base = kaddr + offset;
 	iov.iov_len = size;
-	iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
 	rc = tls_push_data(sk, &msg_iter, size,
 			   flags, TLS_RECORD_TYPE_DATA);
 	kunmap(page);
···
 {
 	struct iov_iter	msg_iter;
 
-	iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
+	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
 	return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
 }