summaryrefslogtreecommitdiff
path: root/fs/9p/v9fs.c
blob: ef338654914095fa464a7b779d6504db526ad61f (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
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
/*
 *  linux/fs/9p/v9fs.c
 *
 *  This file contains functions assisting in mapping VFS to 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 as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/parser.h>
#include <linux/idr.h>

#include "debug.h"
#include "v9fs.h"
#include "9p.h"
#include "v9fs_vfs.h"
#include "transport.h"
#include "mux.h"

/* TODO: sysfs or debugfs interface */
int v9fs_debug_level = 0;	/* feature-rific global debug level  */

/*
  * Option Parsing (code inspired by NFS code)
  *
  */

enum {
	/* Options that take integer arguments */
	Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid, Opt_debug,
	Opt_rfdno, Opt_wfdno,
	/* String options */
	Opt_name, Opt_remotename,
	/* Options that take no arguments */
	Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
	/* Error token */
	Opt_err
};

static match_table_t tokens = {
	{Opt_port, "port=%u"},
	{Opt_msize, "msize=%u"},
	{Opt_uid, "uid=%u"},
	{Opt_gid, "gid=%u"},
	{Opt_afid, "afid=%u"},
	{Opt_rfdno, "rfdno=%u"},
	{Opt_wfdno, "wfdno=%u"},
	{Opt_debug, "debug=%x"},
	{Opt_name, "name=%s"},
	{Opt_remotename, "aname=%s"},
	{Opt_unix, "proto=unix"},
	{Opt_tcp, "proto=tcp"},
	{Opt_fd, "proto=fd"},
	{Opt_tcp, "tcp"},
	{Opt_unix, "unix"},
	{Opt_fd, "fd"},
	{Opt_legacy, "noextend"},
	{Opt_nodevmap, "nodevmap"},
	{Opt_err, NULL}
};

/*
 *  Parse option string.
 */

/**
 * v9fs_parse_options - parse mount options into session structure
 * @options: options string passed from mount
 * @v9ses: existing v9fs session information
 *
 */

static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;
	int ret;

	/* setup defaults */
	v9ses->port = V9FS_PORT;
	v9ses->maxdata = 9000;
	v9ses->proto = PROTO_TCP;
	v9ses->extended = 1;
	v9ses->afid = ~0;
	v9ses->debug = 0;
	v9ses->rfdno = ~0;
	v9ses->wfdno = ~0;

	if (!options)
		return;

	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
		if (token < Opt_name) {
			if ((ret = match_int(&args[0], &option)) < 0) {
				dprintk(DEBUG_ERROR,
					"integer field, but no integer?\n");
				continue;
			}

		}
		switch (token) {
		case Opt_port:
			v9ses->port = option;
			break;
		case Opt_msize:
			v9ses->maxdata = option;
			break;
		case Opt_uid:
			v9ses->uid = option;
			break;
		case Opt_gid:
			v9ses->gid = option;
			break;
		case Opt_afid:
			v9ses->afid = option;
			break;
		case Opt_rfdno:
			v9ses->rfdno = option;
			break;
		case Opt_wfdno:
			v9ses->wfdno = option;
			break;
		case Opt_debug:
			v9ses->debug = option;
			break;
		case Opt_tcp:
			v9ses->proto = PROTO_TCP;
			break;
		case Opt_unix:
			v9ses->proto = PROTO_UNIX;
			break;
		case Opt_fd:
			v9ses->proto = PROTO_FD;
			break;
		case Opt_name:
			match_strcpy(v9ses->name, &args[0]);
			break;
		case Opt_remotename:
			match_strcpy(v9ses->remotename, &args[0]);
			break;
		case Opt_legacy:
			v9ses->extended = 0;
			break;
		case Opt_nodevmap:
			v9ses->nodev = 1;
			break;
		default:
			continue;
		}
	}
}

/**
 * v9fs_inode2v9ses - safely extract v9fs session info from super block
 * @inode: inode to extract information from
 *
 * Paranoid function to extract v9ses information from superblock,
 * if anything is missing it will report an error.
 *
 */

struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
{
	return (inode->i_sb->s_fs_info);
}

/**
 * v9fs_get_idpool - allocate numeric id from pool
 * @p - pool to allocate from
 *
 * XXX - This seems to be an awful generic function, should it be in idr.c with
 *            the lock included in struct idr?
 */

int v9fs_get_idpool(struct v9fs_idpool *p)
{
	int i = 0;
	int error;

retry:
	if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
		return 0;

	if (down_interruptible(&p->lock) == -EINTR) {
		eprintk(KERN_WARNING, "Interrupted while locking\n");
		return -1;
	}

	/* no need to store exactly p, we just need something non-null */
	error = idr_get_new(&p->pool, p, &i);
	up(&p->lock);

	if (error == -EAGAIN)
		goto retry;
	else if (error)
		return -1;

	return i;
}

/**
 * v9fs_put_idpool - release numeric id from pool
 * @p - pool to allocate from
 *
 * XXX - This seems to be an awful generic function, should it be in idr.c with
 *            the lock included in struct idr?
 */

void v9fs_put_idpool(int id, struct v9fs_idpool *p)
{
	if (down_interruptible(&p->lock) == -EINTR) {
		eprintk(KERN_WARNING, "Interrupted while locking\n");
		return;
	}
	idr_remove(&p->pool, id);
	up(&p->lock);
}

/**
 * v9fs_check_idpool - check if the specified id is available
 * @id - id to check
 * @p - pool
 */
int v9fs_check_idpool(int id, struct v9fs_idpool *p)
{
	return idr_find(&p->pool, id) != NULL;
}

/**
 * v9fs_session_init - initialize session
 * @v9ses: session information structure
 * @dev_name: device being mounted
 * @data: options
 *
 */

int
v9fs_session_init(struct v9fs_session_info *v9ses,
		  const char *dev_name, char *data)
{
	struct v9fs_fcall *fcall = NULL;
	struct v9fs_transport *trans_proto;
	int n = 0;
	int newfid = -1;
	int retval = -EINVAL;
	struct v9fs_str *version;

	v9ses->name = __getname();
	if (!v9ses->name)
		return -ENOMEM;

	v9ses->remotename = __getname();
	if (!v9ses->remotename) {
		__putname(v9ses->name);
		return -ENOMEM;
	}

	strcpy(v9ses->name, V9FS_DEFUSER);
	strcpy(v9ses->remotename, V9FS_DEFANAME);

	v9fs_parse_options(data, v9ses);

	/* set global debug level */
	v9fs_debug_level = v9ses->debug;

	/* id pools that are session-dependent: FIDs and TIDs */
	idr_init(&v9ses->fidpool.pool);
	init_MUTEX(&v9ses->fidpool.lock);

	switch (v9ses->proto) {
	case PROTO_TCP:
		trans_proto = &v9fs_trans_tcp;
		break;
	case PROTO_UNIX:
		trans_proto = &v9fs_trans_unix;
		*v9ses->remotename = 0;
		break;
	case PROTO_FD:
		trans_proto = &v9fs_trans_fd;
		*v9ses->remotename = 0;
		break;
	default:
		printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
		retval = -ENOPROTOOPT;
		goto SessCleanUp;
	};

	v9ses->transport = kmalloc(sizeof(*v9ses->transport), GFP_KERNEL);
	if (!v9ses->transport) {
		retval = -ENOMEM;
		goto SessCleanUp;
	}

	memmove(v9ses->transport, trans_proto, sizeof(*v9ses->transport));

	if ((retval = v9ses->transport->init(v9ses, dev_name, data)) < 0) {
		eprintk(KERN_ERR, "problem initializing transport\n");
		goto SessCleanUp;
	}

	v9ses->inprogress = 0;
	v9ses->shutdown = 0;
	v9ses->session_hung = 0;

	v9ses->mux = v9fs_mux_init(v9ses->transport, v9ses->maxdata + V9FS_IOHDRSZ,
		&v9ses->extended);

	if (IS_ERR(v9ses->mux)) {
		retval = PTR_ERR(v9ses->mux);
		v9ses->mux = NULL;
		dprintk(DEBUG_ERROR, "problem initializing mux\n");
		goto SessCleanUp;
	}

	if (v9ses->afid == ~0) {
		if (v9ses->extended)
			retval =
			    v9fs_t_version(v9ses, v9ses->maxdata, "9P2000.u",
					   &fcall);
		else
			retval = v9fs_t_version(v9ses, v9ses->maxdata, "9P2000",
						&fcall);

		if (retval < 0) {
			dprintk(DEBUG_ERROR, "v9fs_t_version failed\n");
			goto FreeFcall;
		}

		version = &fcall->params.rversion.version;
		if (version->len==8 && !memcmp(version->str, "9P2000.u", 8)) {
			dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n");
			v9ses->extended = 1;
		} else if (version->len==6 && !memcmp(version->str, "9P2000", 6)) {
			dprintk(DEBUG_9P, "9P2000 legacy mode enabled\n");
			v9ses->extended = 0;
		} else {
			retval = -EREMOTEIO;
			goto FreeFcall;
		}

		n = fcall->params.rversion.msize;
		kfree(fcall);

		if (n < v9ses->maxdata)
			v9ses->maxdata = n;
	}

	newfid = v9fs_get_idpool(&v9ses->fidpool);
	if (newfid < 0) {
		eprintk(KERN_WARNING, "couldn't allocate FID\n");
		retval = -ENOMEM;
		goto SessCleanUp;
	}
	/* it is a little bit ugly, but we have to prevent newfid */
	/* being the same as afid, so if it is, get a new fid     */
	if (v9ses->afid != ~0 && newfid == v9ses->afid) {
		newfid = v9fs_get_idpool(&v9ses->fidpool);
		if (newfid < 0) {
			eprintk(KERN_WARNING, "couldn't allocate FID\n");
			retval = -ENOMEM;
			goto SessCleanUp;
		}
	}

	if ((retval =
	     v9fs_t_attach(v9ses, v9ses->name, v9ses->remotename, newfid,
			   v9ses->afid, NULL))
	    < 0) {
		dprintk(DEBUG_ERROR, "cannot attach\n");
		goto SessCleanUp;
	}

	if (v9ses->afid != ~0) {
		if (v9fs_t_clunk(v9ses, v9ses->afid))
			dprintk(DEBUG_ERROR, "clunk failed\n");
	}

	return newfid;

      FreeFcall:
	kfree(fcall);

      SessCleanUp:
	v9fs_session_close(v9ses);
	return retval;
}

/**
 * v9fs_session_close - shutdown a session
 * @v9ses: session information structure
 *
 */

void v9fs_session_close(struct v9fs_session_info *v9ses)
{
	if (v9ses->mux) {
		v9fs_mux_destroy(v9ses->mux);
		v9ses->mux = NULL;
	}

	if (v9ses->transport) {
		v9ses->transport->close(v9ses->transport);
		kfree(v9ses->transport);
		v9ses->transport = NULL;
	}

	__putname(v9ses->name);
	__putname(v9ses->remotename);
}

/**
 * v9fs_session_cancel - mark transport as disconnected
 * 	and cancel all pending requests.
 */
void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
	dprintk(DEBUG_ERROR, "cancel session %p\n", v9ses);
	v9ses->transport->status = Disconnected;
	v9fs_mux_cancel(v9ses->mux, -EIO);
}

extern int v9fs_error_init(void);

/**
 * v9fs_init - Initialize module
 *
 */

static int __init init_v9fs(void)
{
	int ret;

	v9fs_error_init();

	printk(KERN_INFO "Installing v9fs 9P2000 file system support\n");

	ret = v9fs_mux_global_init();
	if (!ret)
		ret = register_filesystem(&v9fs_fs_type);

	return ret;
}

/**
 * v9fs_init - shutdown module
 *
 */

static void __exit exit_v9fs(void)
{
	v9fs_mux_global_exit();
	unregister_filesystem(&v9fs_fs_type);
}

module_init(init_v9fs)
module_exit(exit_v9fs)

MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
MODULE_LICENSE("GPL");