summaryrefslogtreecommitdiffstats
path: root/fs/9p/vfs_addr.c
blob: 047855033d32f73f054a074452622499d5cf983c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
// SPDX-License-Identifier: GPL-2.0-only
/*
 * This file contians vfs address (mmap) ops for 9P2000.
 *
 *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/swap.h>
#include <linux/uio.h>
#include <linux/netfs.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <trace/events/netfs.h>

#include "v9fs.h"
#include "v9fs_vfs.h"
#include "cache.h"
#include "fid.h"

static void v9fs_upload_to_server(struct netfs_io_subrequest *subreq)
{
	struct p9_fid *fid = subreq->rreq->netfs_priv;
	int err, len;

	trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
	len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);
	netfs_write_subrequest_terminated(subreq, len ?: err, false);
}

static void v9fs_upload_to_server_worker(struct work_struct *work)
{
	struct netfs_io_subrequest *subreq =
		container_of(work, struct netfs_io_subrequest, work);

	v9fs_upload_to_server(subreq);
}

/*
 * Set up write requests for a writeback slice.  We need to add a write request
 * for each write we want to make.
 */
static void v9fs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
{
	struct netfs_io_subrequest *subreq;

	subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
					    start, len, v9fs_upload_to_server_worker);
	if (subreq)
		netfs_queue_write_request(subreq);
}

/**
 * v9fs_issue_read - Issue a read from 9P
 * @subreq: The read to make
 */
static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
{
	struct netfs_io_request *rreq = subreq->rreq;
	struct p9_fid *fid = rreq->netfs_priv;
	int total, err;

	total = p9_client_read(fid, subreq->start + subreq->transferred,
			       &subreq->io_iter, &err);

	/* if we just extended the file size, any portion not in
	 * cache won't be on server and is zeroes */
	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);

	netfs_subreq_terminated(subreq, err ?: total, false);
}

/**
 * v9fs_init_request - Initialise a request
 * @rreq: The read request
 * @file: The file being read from
 */
static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
{
	struct p9_fid *fid;
	bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||
			rreq->origin == NETFS_WRITEBACK ||
			rreq->origin == NETFS_WRITETHROUGH ||
			rreq->origin == NETFS_LAUNDER_WRITE ||
			rreq->origin == NETFS_UNBUFFERED_WRITE ||
			rreq->origin == NETFS_DIO_WRITE);

	if (file) {
		fid = file->private_data;
		if (!fid)
			goto no_fid;
		p9_fid_get(fid);
	} else {
		fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);
		if (!fid)
			goto no_fid;
	}

	/* we might need to read from a fid that was opened write-only
	 * for read-modify-write of page cache, use the writeback fid
	 * for that */
	WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR));
	rreq->netfs_priv = fid;
	return 0;

no_fid:
	WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
		  rreq->inode->i_ino);
	return -EINVAL;
}

/**
 * v9fs_free_request - Cleanup request initialized by v9fs_init_rreq
 * @rreq: The I/O request to clean up
 */
static void v9fs_free_request(struct netfs_io_request *rreq)
{
	struct p9_fid *fid = rreq->netfs_priv;

	p9_fid_put(fid);
}

const struct netfs_request_ops v9fs_req_ops = {
	.init_request		= v9fs_init_request,
	.free_request		= v9fs_free_request,
	.issue_read		= v9fs_issue_read,
	.create_write_requests	= v9fs_create_write_requests,
};

const struct address_space_operations v9fs_addr_operations = {
	.read_folio		= netfs_read_folio,
	.readahead		= netfs_readahead,
	.dirty_folio		= netfs_dirty_folio,
	.release_folio		= netfs_release_folio,
	.invalidate_folio	= netfs_invalidate_folio,
	.launder_folio		= netfs_launder_folio,
	.direct_IO		= noop_direct_IO,
	.writepages		= netfs_writepages,
};