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(sreq: subreq, what: netfs_sreq_trace_submit);
35 len = p9_client_write(fid, offset: subreq->start, from: &subreq->io_iter, err: &err);
36 netfs_write_subrequest_terminated(op: subreq, transferred_or_error: len ?: err, was_async: 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, dest: NETFS_UPLOAD_TO_SERVER,
56 start, len, worker: 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, offset: subreq->start + subreq->transferred,
72 to: &subreq->io_iter, err: &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(inode: rreq->inode, want_writeable: writing, INVALID_UID, any: 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

source code of linux/fs/9p/vfs_addr.c