fs: introduce f_op->mmap_capabilities for nommu mmap support
[linux-block.git] / fs / 9p / v9fs.c
CommitLineData
9e82cf6a
EVH
1/*
2 * linux/fs/9p/v9fs.c
3 *
4 * This file contains functions assisting in mapping VFS to 9P2000
5 *
8a0dc95f 6 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9e82cf6a
EVH
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
42e8c509
EVH
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
9e82cf6a
EVH
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
23 *
24 */
25
5d385153
JP
26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
9e82cf6a
EVH
28#include <linux/module.h>
29#include <linux/errno.h>
30#include <linux/fs.h>
914e2637 31#include <linux/sched.h>
9e82cf6a
EVH
32#include <linux/parser.h>
33#include <linux/idr.h>
5a0e3ad6 34#include <linux/slab.h>
bd238fb4 35#include <net/9p/9p.h>
bd238fb4 36#include <net/9p/client.h>
8b81ef58 37#include <net/9p/transport.h>
9e82cf6a 38#include "v9fs.h"
9e82cf6a 39#include "v9fs_vfs.h"
60e78d2c
AK
40#include "cache.h"
41
42static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
43static LIST_HEAD(v9fs_sessionlist);
a78ce05d 44struct kmem_cache *v9fs_inode_cache;
9e82cf6a
EVH
45
46/*
60e78d2c
AK
47 * Option Parsing (code inspired by NFS code)
48 * NOTE: each transport will parse its own options
49 */
9e82cf6a
EVH
50
51enum {
52 /* Options that take integer arguments */
8a0dc95f 53 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
9e82cf6a 54 /* String options */
60e78d2c 55 Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
9e82cf6a 56 /* Options that take no arguments */
8a0dc95f 57 Opt_nodevmap,
e03abc0c 58 /* Cache options */
fb89b45c 59 Opt_cache_loose, Opt_fscache, Opt_mmap,
ba17674f 60 /* Access options */
e782ef71 61 Opt_access, Opt_posixacl,
9e82cf6a
EVH
62 /* Error token */
63 Opt_err
64};
65
a447c093 66static const match_table_t tokens = {
9e2f6688 67 {Opt_debug, "debug=%x"},
bd32b82d
LI
68 {Opt_dfltuid, "dfltuid=%u"},
69 {Opt_dfltgid, "dfltgid=%u"},
9e82cf6a 70 {Opt_afid, "afid=%u"},
67543e50 71 {Opt_uname, "uname=%s"},
9e82cf6a 72 {Opt_remotename, "aname=%s"},
9e82cf6a 73 {Opt_nodevmap, "nodevmap"},
60e78d2c 74 {Opt_cache, "cache=%s"},
e03abc0c 75 {Opt_cache_loose, "loose"},
60e78d2c 76 {Opt_fscache, "fscache"},
fb89b45c 77 {Opt_mmap, "mmap"},
60e78d2c 78 {Opt_cachetag, "cachetag=%s"},
ba17674f 79 {Opt_access, "access=%s"},
e782ef71 80 {Opt_posixacl, "posixacl"},
9e82cf6a
EVH
81 {Opt_err, NULL}
82};
83
a2dd43bb
PK
84/* Interpret mount options for cache mode */
85static int get_cache_mode(char *s)
86{
87 int version = -EINVAL;
88
89 if (!strcmp(s, "loose")) {
90 version = CACHE_LOOSE;
5d385153 91 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
a2dd43bb
PK
92 } else if (!strcmp(s, "fscache")) {
93 version = CACHE_FSCACHE;
5d385153 94 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
fb89b45c
DM
95 } else if (!strcmp(s, "mmap")) {
96 version = CACHE_MMAP;
97 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
a2dd43bb
PK
98 } else if (!strcmp(s, "none")) {
99 version = CACHE_NONE;
5d385153 100 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
a2dd43bb 101 } else
5d385153 102 pr_info("Unknown Cache mode %s\n", s);
a2dd43bb
PK
103 return version;
104}
105
9e82cf6a
EVH
106/**
107 * v9fs_parse_options - parse mount options into session structure
9e82cf6a
EVH
108 * @v9ses: existing v9fs session information
109 *
ab31267d 110 * Return 0 upon success, -ERRNO upon failure.
9e82cf6a
EVH
111 */
112
4b53e4b5 113static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
9e82cf6a 114{
d8c8a9e3 115 char *options, *tmp_options;
9e82cf6a 116 substring_t args[MAX_OPT_ARGS];
a80d923e 117 char *p;
8a0dc95f 118 int option = 0;
ba17674f 119 char *s, *e;
ab31267d 120 int ret = 0;
9e82cf6a
EVH
121
122 /* setup defaults */
9e82cf6a
EVH
123 v9ses->afid = ~0;
124 v9ses->debug = 0;
a2dd43bb 125 v9ses->cache = CACHE_NONE;
60e78d2c
AK
126#ifdef CONFIG_9P_FSCACHE
127 v9ses->cachetag = NULL;
128#endif
9e82cf6a 129
4b53e4b5 130 if (!opts)
ab31267d 131 return 0;
9e82cf6a 132
d8c8a9e3 133 tmp_options = kstrdup(opts, GFP_KERNEL);
bf2d29c6
EVH
134 if (!tmp_options) {
135 ret = -ENOMEM;
60e78d2c 136 goto fail_option_alloc;
bf2d29c6 137 }
d8c8a9e3 138 options = tmp_options;
ab31267d 139
9e82cf6a 140 while ((p = strsep(&options, ",")) != NULL) {
4d5077f1 141 int token, r;
9e82cf6a
EVH
142 if (!*p)
143 continue;
144 token = match_token(p, tokens, args);
4d5077f1
AK
145 switch (token) {
146 case Opt_debug:
147 r = match_int(&args[0], &option);
ab31267d 148 if (r < 0) {
5d385153
JP
149 p9_debug(P9_DEBUG_ERROR,
150 "integer field, but no integer?\n");
ab31267d 151 ret = r;
9e82cf6a
EVH
152 continue;
153 }
9e2f6688 154 v9ses->debug = option;
10fa16e7 155#ifdef CONFIG_NET_9P_DEBUG
9e2f6688 156 p9_debug_level = option;
10fa16e7 157#endif
9e2f6688 158 break;
8a0dc95f 159
bd32b82d 160 case Opt_dfltuid:
4d5077f1
AK
161 r = match_int(&args[0], &option);
162 if (r < 0) {
5d385153
JP
163 p9_debug(P9_DEBUG_ERROR,
164 "integer field, but no integer?\n");
4d5077f1
AK
165 ret = r;
166 continue;
167 }
76ed23a5
EB
168 v9ses->dfltuid = make_kuid(current_user_ns(), option);
169 if (!uid_valid(v9ses->dfltuid)) {
170 p9_debug(P9_DEBUG_ERROR,
171 "uid field, but not a uid?\n");
172 ret = -EINVAL;
173 continue;
174 }
9e82cf6a 175 break;
bd32b82d 176 case Opt_dfltgid:
4d5077f1
AK
177 r = match_int(&args[0], &option);
178 if (r < 0) {
5d385153
JP
179 p9_debug(P9_DEBUG_ERROR,
180 "integer field, but no integer?\n");
4d5077f1
AK
181 ret = r;
182 continue;
183 }
76ed23a5
EB
184 v9ses->dfltgid = make_kgid(current_user_ns(), option);
185 if (!gid_valid(v9ses->dfltgid)) {
186 p9_debug(P9_DEBUG_ERROR,
187 "gid field, but not a gid?\n");
188 ret = -EINVAL;
189 continue;
190 }
9e82cf6a
EVH
191 break;
192 case Opt_afid:
4d5077f1
AK
193 r = match_int(&args[0], &option);
194 if (r < 0) {
5d385153
JP
195 p9_debug(P9_DEBUG_ERROR,
196 "integer field, but no integer?\n");
4d5077f1
AK
197 ret = r;
198 continue;
199 }
9e82cf6a
EVH
200 v9ses->afid = option;
201 break;
67543e50 202 case Opt_uname:
e549c133
JL
203 kfree(v9ses->uname);
204 v9ses->uname = match_strdup(&args[0]);
205 if (!v9ses->uname) {
206 ret = -ENOMEM;
207 goto free_and_return;
208 }
9e82cf6a
EVH
209 break;
210 case Opt_remotename:
e549c133
JL
211 kfree(v9ses->aname);
212 v9ses->aname = match_strdup(&args[0]);
213 if (!v9ses->aname) {
214 ret = -ENOMEM;
215 goto free_and_return;
216 }
9e82cf6a 217 break;
9e82cf6a
EVH
218 case Opt_nodevmap:
219 v9ses->nodev = 1;
220 break;
e03abc0c
EVH
221 case Opt_cache_loose:
222 v9ses->cache = CACHE_LOOSE;
223 break;
60e78d2c
AK
224 case Opt_fscache:
225 v9ses->cache = CACHE_FSCACHE;
226 break;
fb89b45c
DM
227 case Opt_mmap:
228 v9ses->cache = CACHE_MMAP;
229 break;
60e78d2c
AK
230 case Opt_cachetag:
231#ifdef CONFIG_9P_FSCACHE
232 v9ses->cachetag = match_strdup(&args[0]);
233#endif
234 break;
235 case Opt_cache:
236 s = match_strdup(&args[0]);
bf2d29c6
EVH
237 if (!s) {
238 ret = -ENOMEM;
5d385153
JP
239 p9_debug(P9_DEBUG_ERROR,
240 "problem allocating copy of cache arg\n");
bf2d29c6
EVH
241 goto free_and_return;
242 }
a2dd43bb
PK
243 ret = get_cache_mode(s);
244 if (ret == -EINVAL) {
245 kfree(s);
246 goto free_and_return;
247 }
60e78d2c 248
a2dd43bb 249 v9ses->cache = ret;
60e78d2c
AK
250 kfree(s);
251 break;
ba17674f
LI
252
253 case Opt_access:
254 s = match_strdup(&args[0]);
bf2d29c6
EVH
255 if (!s) {
256 ret = -ENOMEM;
5d385153
JP
257 p9_debug(P9_DEBUG_ERROR,
258 "problem allocating copy of access arg\n");
bf2d29c6
EVH
259 goto free_and_return;
260 }
60e78d2c 261
ba17674f
LI
262 v9ses->flags &= ~V9FS_ACCESS_MASK;
263 if (strcmp(s, "user") == 0)
264 v9ses->flags |= V9FS_ACCESS_USER;
265 else if (strcmp(s, "any") == 0)
266 v9ses->flags |= V9FS_ACCESS_ANY;
76381a42 267 else if (strcmp(s, "client") == 0) {
76381a42 268 v9ses->flags |= V9FS_ACCESS_CLIENT;
76381a42 269 } else {
76ed23a5 270 uid_t uid;
ba17674f 271 v9ses->flags |= V9FS_ACCESS_SINGLE;
76ed23a5 272 uid = simple_strtoul(s, &e, 10);
a2dd43bb
PK
273 if (*e != '\0') {
274 ret = -EINVAL;
5d385153
JP
275 pr_info("Unknown access argument %s\n",
276 s);
a2dd43bb
PK
277 kfree(s);
278 goto free_and_return;
279 }
76ed23a5
EB
280 v9ses->uid = make_kuid(current_user_ns(), uid);
281 if (!uid_valid(v9ses->uid)) {
282 ret = -EINVAL;
283 pr_info("Uknown uid %s\n", s);
284 kfree(s);
285 goto free_and_return;
286 }
ba17674f 287 }
a2dd43bb 288
0a976297 289 kfree(s);
ba17674f
LI
290 break;
291
e782ef71
VJJ
292 case Opt_posixacl:
293#ifdef CONFIG_9P_FS_POSIX_ACL
294 v9ses->flags |= V9FS_POSIX_ACL;
295#else
5d385153
JP
296 p9_debug(P9_DEBUG_ERROR,
297 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
e782ef71
VJJ
298#endif
299 break;
300
9e82cf6a
EVH
301 default:
302 continue;
303 }
304 }
d8c8a9e3 305
bf2d29c6 306free_and_return:
d8c8a9e3 307 kfree(tmp_options);
60e78d2c 308fail_option_alloc:
bf2d29c6 309 return ret;
9e82cf6a
EVH
310}
311
9e82cf6a
EVH
312/**
313 * v9fs_session_init - initialize session
314 * @v9ses: session information structure
315 * @dev_name: device being mounted
316 * @data: options
317 *
318 */
319
bd238fb4 320struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
9e82cf6a
EVH
321 const char *dev_name, char *data)
322{
9e82cf6a 323 int retval = -EINVAL;
bd238fb4 324 struct p9_fid *fid;
ab31267d 325 int rc;
9e82cf6a 326
e549c133 327 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
ba17674f 328 if (!v9ses->uname)
bd238fb4 329 return ERR_PTR(-ENOMEM);
9e82cf6a 330
e549c133 331 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
ba17674f 332 if (!v9ses->aname) {
e549c133 333 kfree(v9ses->uname);
bd238fb4 334 return ERR_PTR(-ENOMEM);
9e82cf6a 335 }
a534c8d1 336 init_rwsem(&v9ses->rename_sem);
9e82cf6a 337
b4caecd4 338 rc = bdi_setup_and_register(&v9ses->bdi, "9p");
0ed07ddb 339 if (rc) {
e549c133
JL
340 kfree(v9ses->aname);
341 kfree(v9ses->uname);
0ed07ddb
JA
342 return ERR_PTR(rc);
343 }
344
60e78d2c
AK
345 spin_lock(&v9fs_sessionlist_lock);
346 list_add(&v9ses->slist, &v9fs_sessionlist);
347 spin_unlock(&v9fs_sessionlist_lock);
348
76ed23a5 349 v9ses->uid = INVALID_UID;
bd32b82d
LI
350 v9ses->dfltuid = V9FS_DEFUID;
351 v9ses->dfltgid = V9FS_DEFGID;
ab31267d 352
4b53e4b5 353 v9ses->clnt = p9_client_create(dev_name, data);
bd238fb4
LI
354 if (IS_ERR(v9ses->clnt)) {
355 retval = PTR_ERR(v9ses->clnt);
356 v9ses->clnt = NULL;
5d385153 357 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
bd238fb4 358 goto error;
9e82cf6a
EVH
359 }
360
6752a1eb
VJJ
361 v9ses->flags = V9FS_ACCESS_USER;
362
363 if (p9_is_proto_dotl(v9ses->clnt)) {
364 v9ses->flags = V9FS_ACCESS_CLIENT;
476ada04 365 v9ses->flags |= V9FS_PROTO_2000L;
6752a1eb 366 } else if (p9_is_proto_dotu(v9ses->clnt)) {
476ada04 367 v9ses->flags |= V9FS_PROTO_2000U;
6752a1eb
VJJ
368 }
369
370 rc = v9fs_parse_options(v9ses, data);
371 if (rc < 0) {
372 retval = rc;
373 goto error;
374 }
ba17674f 375
fbedadc1 376 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
8a0dc95f 377
76381a42
AK
378 if (!v9fs_proto_dotl(v9ses) &&
379 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
380 /*
381 * We support ACCESS_CLIENT only for dotl.
382 * Fall back to ACCESS_USER
383 */
384 v9ses->flags &= ~V9FS_ACCESS_MASK;
385 v9ses->flags |= V9FS_ACCESS_USER;
386 }
387 /*FIXME !! */
ba17674f 388 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
9ffaf63e 389 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
ba17674f
LI
390 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
391
392 v9ses->flags &= ~V9FS_ACCESS_MASK;
393 v9ses->flags |= V9FS_ACCESS_ANY;
76ed23a5 394 v9ses->uid = INVALID_UID;
ba17674f 395 }
e782ef71
VJJ
396 if (!v9fs_proto_dotl(v9ses) ||
397 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
398 /*
399 * We support ACL checks on clinet only if the protocol is
400 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
401 */
402 v9ses->flags &= ~V9FS_ACL_MASK;
403 }
ba17674f 404
f791f7c5 405 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
ba17674f 406 v9ses->aname);
bd238fb4
LI
407 if (IS_ERR(fid)) {
408 retval = PTR_ERR(fid);
409 fid = NULL;
5d385153 410 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
bd238fb4 411 goto error;
9e82cf6a
EVH
412 }
413
ba17674f
LI
414 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
415 fid->uid = v9ses->uid;
416 else
b4642556 417 fid->uid = INVALID_UID;
ba17674f 418
60e78d2c
AK
419#ifdef CONFIG_9P_FSCACHE
420 /* register the session for caching */
421 v9fs_cache_session_get_cookie(v9ses);
422#endif
423
bd238fb4 424 return fid;
9e82cf6a 425
bd238fb4 426error:
0ed07ddb 427 bdi_destroy(&v9ses->bdi);
bd238fb4 428 return ERR_PTR(retval);
9e82cf6a
EVH
429}
430
431/**
432 * v9fs_session_close - shutdown a session
433 * @v9ses: session information structure
434 *
435 */
436
437void v9fs_session_close(struct v9fs_session_info *v9ses)
438{
bd238fb4
LI
439 if (v9ses->clnt) {
440 p9_client_destroy(v9ses->clnt);
441 v9ses->clnt = NULL;
3cf6429a 442 }
9e82cf6a 443
60e78d2c
AK
444#ifdef CONFIG_9P_FSCACHE
445 if (v9ses->fscache) {
446 v9fs_cache_session_put_cookie(v9ses);
447 kfree(v9ses->cachetag);
448 }
449#endif
e549c133
JL
450 kfree(v9ses->uname);
451 kfree(v9ses->aname);
60e78d2c 452
0ed07ddb
JA
453 bdi_destroy(&v9ses->bdi);
454
60e78d2c
AK
455 spin_lock(&v9fs_sessionlist_lock);
456 list_del(&v9ses->slist);
457 spin_unlock(&v9fs_sessionlist_lock);
9e82cf6a
EVH
458}
459
322b329a 460/**
ee443996
EVH
461 * v9fs_session_cancel - terminate a session
462 * @v9ses: session to terminate
463 *
464 * mark transport as disconnected and cancel all pending requests.
322b329a 465 */
ee443996 466
322b329a 467void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
5d385153 468 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
bd238fb4 469 p9_client_disconnect(v9ses->clnt);
322b329a
EVH
470}
471
6d96d3ab
AK
472/**
473 * v9fs_session_begin_cancel - Begin terminate of a session
474 * @v9ses: session to terminate
475 *
476 * After this call we don't allow any request other than clunk.
477 */
478
479void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
480{
5d385153 481 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
6d96d3ab
AK
482 p9_client_begin_disconnect(v9ses->clnt);
483}
484
9e82cf6a
EVH
485extern int v9fs_error_init(void);
486
60e78d2c
AK
487static struct kobject *v9fs_kobj;
488
489#ifdef CONFIG_9P_FSCACHE
9e82cf6a 490/**
60e78d2c
AK
491 * caches_show - list caches associated with a session
492 *
493 * Returns the size of buffer written.
494 */
495
496static ssize_t caches_show(struct kobject *kobj,
497 struct kobj_attribute *attr,
498 char *buf)
499{
500 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
501 struct v9fs_session_info *v9ses;
502
503 spin_lock(&v9fs_sessionlist_lock);
504 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
505 if (v9ses->cachetag) {
506 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
507 if (n < 0) {
508 count = n;
509 break;
510 }
511
512 count += n;
513 limit -= n;
514 }
515 }
516
517 spin_unlock(&v9fs_sessionlist_lock);
518 return count;
519}
520
521static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
522#endif /* CONFIG_9P_FSCACHE */
523
524static struct attribute *v9fs_attrs[] = {
525#ifdef CONFIG_9P_FSCACHE
526 &v9fs_attr_cache.attr,
527#endif
528 NULL,
529};
530
531static struct attribute_group v9fs_attr_group = {
532 .attrs = v9fs_attrs,
533};
534
535/**
536 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
537 *
538 */
539
bdbeacde 540static int __init v9fs_sysfs_init(void)
60e78d2c
AK
541{
542 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
543 if (!v9fs_kobj)
544 return -ENOMEM;
545
546 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
547 kobject_put(v9fs_kobj);
548 return -ENOMEM;
549 }
550
551 return 0;
552}
553
554/**
555 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
556 *
557 */
558
559static void v9fs_sysfs_cleanup(void)
560{
561 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
562 kobject_put(v9fs_kobj);
563}
564
a78ce05d
AK
565static void v9fs_inode_init_once(void *foo)
566{
567 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
568#ifdef CONFIG_9P_FSCACHE
569 v9inode->fscache = NULL;
a78ce05d 570#endif
fd2421f5 571 memset(&v9inode->qid, 0, sizeof(v9inode->qid));
a78ce05d
AK
572 inode_init_once(&v9inode->vfs_inode);
573}
574
575/**
576 * v9fs_init_inode_cache - initialize a cache for 9P
577 * Returns 0 on success.
578 */
579static int v9fs_init_inode_cache(void)
580{
581 v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
582 sizeof(struct v9fs_inode),
583 0, (SLAB_RECLAIM_ACCOUNT|
584 SLAB_MEM_SPREAD),
585 v9fs_inode_init_once);
586 if (!v9fs_inode_cache)
587 return -ENOMEM;
588
589 return 0;
590}
591
592/**
593 * v9fs_destroy_inode_cache - destroy the cache of 9P inode
594 *
595 */
596static void v9fs_destroy_inode_cache(void)
597{
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598 /*
599 * Make sure all delayed rcu free inodes are flushed before we
600 * destroy cache.
601 */
602 rcu_barrier();
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603 kmem_cache_destroy(v9fs_inode_cache);
604}
605
606static int v9fs_cache_register(void)
607{
608 int ret;
609 ret = v9fs_init_inode_cache();
610 if (ret < 0)
611 return ret;
612#ifdef CONFIG_9P_FSCACHE
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613 ret = fscache_register_netfs(&v9fs_cache_netfs);
614 if (ret < 0)
615 v9fs_destroy_inode_cache();
a78ce05d 616#endif
8061a6fa 617 return ret;
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618}
619
620static void v9fs_cache_unregister(void)
621{
622 v9fs_destroy_inode_cache();
623#ifdef CONFIG_9P_FSCACHE
624 fscache_unregister_netfs(&v9fs_cache_netfs);
625#endif
626}
627
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628/**
629 * init_v9fs - Initialize module
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630 *
631 */
632
633static int __init init_v9fs(void)
634{
60e78d2c 635 int err;
5d385153 636 pr_info("Installing v9fs 9p2000 file system support\n");
a80d923e 637 /* TODO: Setup list of registered trasnport modules */
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638
639 err = v9fs_cache_register();
640 if (err < 0) {
5d385153 641 pr_err("Failed to register v9fs for caching\n");
2226a288 642 return err;
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643 }
644
645 err = v9fs_sysfs_init();
646 if (err < 0) {
5d385153 647 pr_err("Failed to register with sysfs\n");
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648 goto out_cache;
649 }
650 err = register_filesystem(&v9fs_fs_type);
651 if (err < 0) {
652 pr_err("Failed to register filesystem\n");
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653 goto out_sysfs_cleanup;
654 }
655
656 return 0;
657
658out_sysfs_cleanup:
659 v9fs_sysfs_cleanup();
660
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661out_cache:
662 v9fs_cache_unregister();
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663
664 return err;
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665}
666
667/**
60e78d2c 668 * exit_v9fs - shutdown module
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669 *
670 */
671
672static void __exit exit_v9fs(void)
673{
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674 v9fs_sysfs_cleanup();
675 v9fs_cache_unregister();
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676 unregister_filesystem(&v9fs_fs_type);
677}
678
679module_init(init_v9fs)
680module_exit(exit_v9fs)
681
bd238fb4 682MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
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683MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
684MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
685MODULE_LICENSE("GPL");