summaryrefslogtreecommitdiffstats
path: root/fs/9p/vfs_file.c
blob: 6e7678e4852ffa53b2e84fdd06dbf4ae8ce66b5a (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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 *  linux/fs/9p/vfs_file.c
 *
 * This file contians vfs file ops for 9P2000.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <asm/uaccess.h>
#include <linux/idr.h>

#include "debug.h"
#include "v9fs.h"
#include "9p.h"
#include "v9fs_vfs.h"
#include "fid.h"

static const struct file_operations v9fs_cached_file_operations;

/**
 * v9fs_file_open - open a file (or directory)
 * @inode: inode to be opened
 * @file: file being opened
 *
 */

int v9fs_file_open(struct inode *inode, struct file *file)
{
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	struct v9fs_fid *vfid;
	struct v9fs_fcall *fcall = NULL;
	int omode;
	int err;

	dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file);

	vfid = v9fs_fid_clone(file->f_path.dentry);
	if (IS_ERR(vfid))
		return PTR_ERR(vfid);

	omode = v9fs_uflags2omode(file->f_flags);
	err = v9fs_t_open(v9ses, vfid->fid, omode, &fcall);
	if (err < 0) {
		PRINT_FCALL_ERROR("open failed", fcall);
		goto Clunk_Fid;
	}

	file->private_data = vfid;
	vfid->fidopen = 1;
	vfid->fidclunked = 0;
	vfid->iounit = fcall->params.ropen.iounit;
	vfid->rdir_pos = 0;
	vfid->rdir_fcall = NULL;
	vfid->filp = file;
	kfree(fcall);

	if((vfid->qid.version) && (v9ses->cache)) {
		dprintk(DEBUG_VFS, "cached");
		/* enable cached file options */
		if(file->f_op == &v9fs_file_operations)
			file->f_op = &v9fs_cached_file_operations;
	}

	return 0;

Clunk_Fid:
	v9fs_fid_clunk(v9ses, vfid);
	kfree(fcall);

	return err;
}

/**
 * v9fs_file_lock - lock a file (or directory)
 * @inode: inode to be opened
 * @file: file being opened
 *
 * XXX - this looks like a local only lock, we should extend into 9P
 *       by using open exclusive
 */

static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
{
	int res = 0;
	struct inode *inode = filp->f_path.dentry->d_inode;

	dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);

	/* No mandatory locks */
	if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
		return -ENOLCK;

	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
		filemap_write_and_wait(inode->i_mapping);
		invalidate_mapping_pages(&inode->i_data, 0, -1);
	}

	return res;
}

/**
 * v9fs_file_read - read from a file
 * @filep: file pointer to read
 * @data: data buffer to read data into
 * @count: size of buffer
 * @offset: offset at which to read data
 *
 */
static ssize_t
v9fs_file_read(struct file *filp, char __user * data, size_t count,
	       loff_t * offset)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	struct v9fs_fid *v9f = filp->private_data;
	struct v9fs_fcall *fcall = NULL;
	int fid = v9f->fid;
	int rsize = 0;
	int result = 0;
	int total = 0;
	int n;

	dprintk(DEBUG_VFS, "\n");

	rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	if (v9f->iounit != 0 && rsize > v9f->iounit)
		rsize = v9f->iounit;

	do {
		if (count < rsize)
			rsize = count;

		result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall);

		if (result < 0) {
			printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n",
			       result);

			kfree(fcall);
			return total;
		} else
			*offset += result;

		n = copy_to_user(data, fcall->params.rread.data, result);
		if (n) {
			dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n);
			kfree(fcall);
			return -EFAULT;
		}

		count -= result;
		data += result;
		total += result;

		kfree(fcall);

		if (result < rsize)
			break;
	} while (count);

	return total;
}

/**
 * v9fs_file_write - write to a file
 * @filep: file pointer to write
 * @data: data buffer to write data from
 * @count: size of buffer
 * @offset: offset at which to write data
 *
 */

static ssize_t
v9fs_file_write(struct file *filp, const char __user * data,
		size_t count, loff_t * offset)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
	struct v9fs_fid *v9fid = filp->private_data;
	struct v9fs_fcall *fcall;
	int fid = v9fid->fid;
	int result = -EIO;
	int rsize = 0;
	int total = 0;

	dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
		(int)*offset);
	rsize = v9ses->maxdata - V9FS_IOHDRSZ;
	if (v9fid->iounit != 0 && rsize > v9fid->iounit)
		rsize = v9fid->iounit;

	do {
		if (count < rsize)
			rsize = count;

		result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall);
		if (result < 0) {
			PRINT_FCALL_ERROR("error while writing", fcall);
			kfree(fcall);
			return result;
		} else
			*offset += result;

		kfree(fcall);
		fcall = NULL;

		if (result != rsize) {
			eprintk(KERN_ERR,
				"short write: v9fs_t_write returned %d\n",
				result);
			break;
		}

		count -= result;
		data += result;
		total += result;
	} while (count);

	invalidate_inode_pages2(inode->i_mapping);
	return total;
}

static const struct file_operations v9fs_cached_file_operations = {
	.llseek = generic_file_llseek,
	.read = do_sync_read,
	.aio_read = generic_file_aio_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_mmap,
};

const struct file_operations v9fs_file_operations = {
	.llseek = generic_file_llseek,
	.read = v9fs_file_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_mmap,
};