1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contians vfs address (mmap) ops for 9P2000.
4 *
5 *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
6 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
9#include <linux/module.h>
10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/file.h>
13#include <linux/stat.h>
14#include <linux/string.h>
15#include <linux/pagemap.h>
16#include <linux/sched.h>
17#include <linux/swap.h>
18#include <linux/uio.h>
19#include <linux/netfs.h>
20#include <net/9p/9p.h>
21#include <net/9p/client.h>
22#include <trace/events/netfs.h>
23
24#include "v9fs.h"
25#include "v9fs_vfs.h"
26#include "cache.h"
27#include "fid.h"
28
29static void v9fs_upload_to_server(struct netfs_io_subrequest *subreq)
30{
31	struct p9_fid *fid = subreq->rreq->netfs_priv;
32	int err, len;
33
34	trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
35	len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);
36	netfs_write_subrequest_terminated(subreq, len ?: err, false);
37}
38
39static void v9fs_upload_to_server_worker(struct work_struct *work)
40{
41	struct netfs_io_subrequest *subreq =
42		container_of(work, struct netfs_io_subrequest, work);
43
44	v9fs_upload_to_server(subreq);
45}
46
47/*
48 * Set up write requests for a writeback slice.  We need to add a write request
49 * for each write we want to make.
50 */
51static void v9fs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
52{
53	struct netfs_io_subrequest *subreq;
54
55	subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
56					    start, len, v9fs_upload_to_server_worker);
57	if (subreq)
58		netfs_queue_write_request(subreq);
59}
60
61/**
62 * v9fs_issue_read - Issue a read from 9P
63 * @subreq: The read to make
64 */
65static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
66{
67	struct netfs_io_request *rreq = subreq->rreq;
68	struct p9_fid *fid = rreq->netfs_priv;
69	int total, err;
70
71	total = p9_client_read(fid, subreq->start + subreq->transferred,
72			       &subreq->io_iter, &err);
73
74	/* if we just extended the file size, any portion not in
75	 * cache won't be on server and is zeroes */
76	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
77
78	netfs_subreq_terminated(subreq, err ?: total, false);
79}
80
81/**
82 * v9fs_init_request - Initialise a request
83 * @rreq: The read request
84 * @file: The file being read from
85 */
86static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
87{
88	struct p9_fid *fid;
89	bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||
90			rreq->origin == NETFS_WRITEBACK ||
91			rreq->origin == NETFS_WRITETHROUGH ||
92			rreq->origin == NETFS_LAUNDER_WRITE ||
93			rreq->origin == NETFS_UNBUFFERED_WRITE ||
94			rreq->origin == NETFS_DIO_WRITE);
95
96	if (file) {
97		fid = file->private_data;
98		if (!fid)
99			goto no_fid;
100		p9_fid_get(fid);
101	} else {
102		fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);
103		if (!fid)
104			goto no_fid;
105	}
106
107	/* we might need to read from a fid that was opened write-only
108	 * for read-modify-write of page cache, use the writeback fid
109	 * for that */
110	WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR));
111	rreq->netfs_priv = fid;
112	return 0;
113
114no_fid:
115	WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
116		  rreq->inode->i_ino);
117	return -EINVAL;
118}
119
120/**
121 * v9fs_free_request - Cleanup request initialized by v9fs_init_rreq
122 * @rreq: The I/O request to clean up
123 */
124static void v9fs_free_request(struct netfs_io_request *rreq)
125{
126	struct p9_fid *fid = rreq->netfs_priv;
127
128	p9_fid_put(fid);
129}
130
131const struct netfs_request_ops v9fs_req_ops = {
132	.init_request		= v9fs_init_request,
133	.free_request		= v9fs_free_request,
134	.issue_read		= v9fs_issue_read,
135	.create_write_requests	= v9fs_create_write_requests,
136};
137
138const struct address_space_operations v9fs_addr_operations = {
139	.read_folio		= netfs_read_folio,
140	.readahead		= netfs_readahead,
141	.dirty_folio		= netfs_dirty_folio,
142	.release_folio		= netfs_release_folio,
143	.invalidate_folio	= netfs_invalidate_folio,
144	.launder_folio		= netfs_launder_folio,
145	.direct_IO		= noop_direct_IO,
146	.writepages		= netfs_writepages,
147};
148