Loading...
1/*
2 * linux/fs/9p/v9fs.c
3 *
4 * This file contains functions assisting in mapping VFS to 9P2000
5 *
6 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
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
26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28#include <linux/module.h>
29#include <linux/errno.h>
30#include <linux/fs.h>
31#include <linux/sched.h>
32#include <linux/parser.h>
33#include <linux/idr.h>
34#include <linux/slab.h>
35#include <net/9p/9p.h>
36#include <net/9p/client.h>
37#include <net/9p/transport.h>
38#include "v9fs.h"
39#include "v9fs_vfs.h"
40#include "cache.h"
41
42static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
43static LIST_HEAD(v9fs_sessionlist);
44struct kmem_cache *v9fs_inode_cache;
45
46/*
47 * Option Parsing (code inspired by NFS code)
48 * NOTE: each transport will parse its own options
49 */
50
51enum {
52 /* Options that take integer arguments */
53 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
54 /* String options */
55 Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
56 /* Options that take no arguments */
57 Opt_nodevmap,
58 /* Cache options */
59 Opt_cache_loose, Opt_fscache, Opt_mmap,
60 /* Access options */
61 Opt_access, Opt_posixacl,
62 /* Error token */
63 Opt_err
64};
65
66static const match_table_t tokens = {
67 {Opt_debug, "debug=%x"},
68 {Opt_dfltuid, "dfltuid=%u"},
69 {Opt_dfltgid, "dfltgid=%u"},
70 {Opt_afid, "afid=%u"},
71 {Opt_uname, "uname=%s"},
72 {Opt_remotename, "aname=%s"},
73 {Opt_nodevmap, "nodevmap"},
74 {Opt_cache, "cache=%s"},
75 {Opt_cache_loose, "loose"},
76 {Opt_fscache, "fscache"},
77 {Opt_mmap, "mmap"},
78 {Opt_cachetag, "cachetag=%s"},
79 {Opt_access, "access=%s"},
80 {Opt_posixacl, "posixacl"},
81 {Opt_err, NULL}
82};
83
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;
91 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
92 } else if (!strcmp(s, "fscache")) {
93 version = CACHE_FSCACHE;
94 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
95 } else if (!strcmp(s, "mmap")) {
96 version = CACHE_MMAP;
97 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
98 } else if (!strcmp(s, "none")) {
99 version = CACHE_NONE;
100 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
101 } else
102 pr_info("Unknown Cache mode %s\n", s);
103 return version;
104}
105
106/**
107 * v9fs_parse_options - parse mount options into session structure
108 * @v9ses: existing v9fs session information
109 *
110 * Return 0 upon success, -ERRNO upon failure.
111 */
112
113static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
114{
115 char *options, *tmp_options;
116 substring_t args[MAX_OPT_ARGS];
117 char *p;
118 int option = 0;
119 char *s, *e;
120 int ret = 0;
121
122 /* setup defaults */
123 v9ses->afid = ~0;
124 v9ses->debug = 0;
125 v9ses->cache = CACHE_NONE;
126#ifdef CONFIG_9P_FSCACHE
127 v9ses->cachetag = NULL;
128#endif
129
130 if (!opts)
131 return 0;
132
133 tmp_options = kstrdup(opts, GFP_KERNEL);
134 if (!tmp_options) {
135 ret = -ENOMEM;
136 goto fail_option_alloc;
137 }
138 options = tmp_options;
139
140 while ((p = strsep(&options, ",")) != NULL) {
141 int token, r;
142 if (!*p)
143 continue;
144 token = match_token(p, tokens, args);
145 switch (token) {
146 case Opt_debug:
147 r = match_int(&args[0], &option);
148 if (r < 0) {
149 p9_debug(P9_DEBUG_ERROR,
150 "integer field, but no integer?\n");
151 ret = r;
152 continue;
153 }
154 v9ses->debug = option;
155#ifdef CONFIG_NET_9P_DEBUG
156 p9_debug_level = option;
157#endif
158 break;
159
160 case Opt_dfltuid:
161 r = match_int(&args[0], &option);
162 if (r < 0) {
163 p9_debug(P9_DEBUG_ERROR,
164 "integer field, but no integer?\n");
165 ret = r;
166 continue;
167 }
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 }
175 break;
176 case Opt_dfltgid:
177 r = match_int(&args[0], &option);
178 if (r < 0) {
179 p9_debug(P9_DEBUG_ERROR,
180 "integer field, but no integer?\n");
181 ret = r;
182 continue;
183 }
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 }
191 break;
192 case Opt_afid:
193 r = match_int(&args[0], &option);
194 if (r < 0) {
195 p9_debug(P9_DEBUG_ERROR,
196 "integer field, but no integer?\n");
197 ret = r;
198 continue;
199 }
200 v9ses->afid = option;
201 break;
202 case Opt_uname:
203 kfree(v9ses->uname);
204 v9ses->uname = match_strdup(&args[0]);
205 if (!v9ses->uname) {
206 ret = -ENOMEM;
207 goto free_and_return;
208 }
209 break;
210 case Opt_remotename:
211 kfree(v9ses->aname);
212 v9ses->aname = match_strdup(&args[0]);
213 if (!v9ses->aname) {
214 ret = -ENOMEM;
215 goto free_and_return;
216 }
217 break;
218 case Opt_nodevmap:
219 v9ses->nodev = 1;
220 break;
221 case Opt_cache_loose:
222 v9ses->cache = CACHE_LOOSE;
223 break;
224 case Opt_fscache:
225 v9ses->cache = CACHE_FSCACHE;
226 break;
227 case Opt_mmap:
228 v9ses->cache = CACHE_MMAP;
229 break;
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]);
237 if (!s) {
238 ret = -ENOMEM;
239 p9_debug(P9_DEBUG_ERROR,
240 "problem allocating copy of cache arg\n");
241 goto free_and_return;
242 }
243 ret = get_cache_mode(s);
244 if (ret == -EINVAL) {
245 kfree(s);
246 goto free_and_return;
247 }
248
249 v9ses->cache = ret;
250 kfree(s);
251 break;
252
253 case Opt_access:
254 s = match_strdup(&args[0]);
255 if (!s) {
256 ret = -ENOMEM;
257 p9_debug(P9_DEBUG_ERROR,
258 "problem allocating copy of access arg\n");
259 goto free_and_return;
260 }
261
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;
267 else if (strcmp(s, "client") == 0) {
268 v9ses->flags |= V9FS_ACCESS_CLIENT;
269 } else {
270 uid_t uid;
271 v9ses->flags |= V9FS_ACCESS_SINGLE;
272 uid = simple_strtoul(s, &e, 10);
273 if (*e != '\0') {
274 ret = -EINVAL;
275 pr_info("Unknown access argument %s\n",
276 s);
277 kfree(s);
278 goto free_and_return;
279 }
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 }
287 }
288
289 kfree(s);
290 break;
291
292 case Opt_posixacl:
293#ifdef CONFIG_9P_FS_POSIX_ACL
294 v9ses->flags |= V9FS_POSIX_ACL;
295#else
296 p9_debug(P9_DEBUG_ERROR,
297 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
298#endif
299 break;
300
301 default:
302 continue;
303 }
304 }
305
306free_and_return:
307 kfree(tmp_options);
308fail_option_alloc:
309 return ret;
310}
311
312/**
313 * v9fs_session_init - initialize session
314 * @v9ses: session information structure
315 * @dev_name: device being mounted
316 * @data: options
317 *
318 */
319
320struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
321 const char *dev_name, char *data)
322{
323 struct p9_fid *fid;
324 int rc = -ENOMEM;
325
326 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
327 if (!v9ses->uname)
328 goto err_names;
329
330 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
331 if (!v9ses->aname)
332 goto err_names;
333 init_rwsem(&v9ses->rename_sem);
334
335 rc = bdi_setup_and_register(&v9ses->bdi, "9p");
336 if (rc)
337 goto err_names;
338
339 v9ses->uid = INVALID_UID;
340 v9ses->dfltuid = V9FS_DEFUID;
341 v9ses->dfltgid = V9FS_DEFGID;
342
343 v9ses->clnt = p9_client_create(dev_name, data);
344 if (IS_ERR(v9ses->clnt)) {
345 rc = PTR_ERR(v9ses->clnt);
346 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
347 goto err_bdi;
348 }
349
350 v9ses->flags = V9FS_ACCESS_USER;
351
352 if (p9_is_proto_dotl(v9ses->clnt)) {
353 v9ses->flags = V9FS_ACCESS_CLIENT;
354 v9ses->flags |= V9FS_PROTO_2000L;
355 } else if (p9_is_proto_dotu(v9ses->clnt)) {
356 v9ses->flags |= V9FS_PROTO_2000U;
357 }
358
359 rc = v9fs_parse_options(v9ses, data);
360 if (rc < 0)
361 goto err_clnt;
362
363 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
364
365 if (!v9fs_proto_dotl(v9ses) &&
366 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
367 /*
368 * We support ACCESS_CLIENT only for dotl.
369 * Fall back to ACCESS_USER
370 */
371 v9ses->flags &= ~V9FS_ACCESS_MASK;
372 v9ses->flags |= V9FS_ACCESS_USER;
373 }
374 /*FIXME !! */
375 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
376 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
377 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
378
379 v9ses->flags &= ~V9FS_ACCESS_MASK;
380 v9ses->flags |= V9FS_ACCESS_ANY;
381 v9ses->uid = INVALID_UID;
382 }
383 if (!v9fs_proto_dotl(v9ses) ||
384 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
385 /*
386 * We support ACL checks on clinet only if the protocol is
387 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
388 */
389 v9ses->flags &= ~V9FS_ACL_MASK;
390 }
391
392 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
393 v9ses->aname);
394 if (IS_ERR(fid)) {
395 rc = PTR_ERR(fid);
396 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
397 goto err_clnt;
398 }
399
400 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
401 fid->uid = v9ses->uid;
402 else
403 fid->uid = INVALID_UID;
404
405#ifdef CONFIG_9P_FSCACHE
406 /* register the session for caching */
407 v9fs_cache_session_get_cookie(v9ses);
408#endif
409 spin_lock(&v9fs_sessionlist_lock);
410 list_add(&v9ses->slist, &v9fs_sessionlist);
411 spin_unlock(&v9fs_sessionlist_lock);
412
413 return fid;
414
415err_clnt:
416 p9_client_destroy(v9ses->clnt);
417err_bdi:
418 bdi_destroy(&v9ses->bdi);
419err_names:
420 kfree(v9ses->uname);
421 kfree(v9ses->aname);
422 return ERR_PTR(rc);
423}
424
425/**
426 * v9fs_session_close - shutdown a session
427 * @v9ses: session information structure
428 *
429 */
430
431void v9fs_session_close(struct v9fs_session_info *v9ses)
432{
433 if (v9ses->clnt) {
434 p9_client_destroy(v9ses->clnt);
435 v9ses->clnt = NULL;
436 }
437
438#ifdef CONFIG_9P_FSCACHE
439 if (v9ses->fscache) {
440 v9fs_cache_session_put_cookie(v9ses);
441 kfree(v9ses->cachetag);
442 }
443#endif
444 kfree(v9ses->uname);
445 kfree(v9ses->aname);
446
447 bdi_destroy(&v9ses->bdi);
448
449 spin_lock(&v9fs_sessionlist_lock);
450 list_del(&v9ses->slist);
451 spin_unlock(&v9fs_sessionlist_lock);
452}
453
454/**
455 * v9fs_session_cancel - terminate a session
456 * @v9ses: session to terminate
457 *
458 * mark transport as disconnected and cancel all pending requests.
459 */
460
461void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
462 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
463 p9_client_disconnect(v9ses->clnt);
464}
465
466/**
467 * v9fs_session_begin_cancel - Begin terminate of a session
468 * @v9ses: session to terminate
469 *
470 * After this call we don't allow any request other than clunk.
471 */
472
473void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
474{
475 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
476 p9_client_begin_disconnect(v9ses->clnt);
477}
478
479extern int v9fs_error_init(void);
480
481static struct kobject *v9fs_kobj;
482
483#ifdef CONFIG_9P_FSCACHE
484/**
485 * caches_show - list caches associated with a session
486 *
487 * Returns the size of buffer written.
488 */
489
490static ssize_t caches_show(struct kobject *kobj,
491 struct kobj_attribute *attr,
492 char *buf)
493{
494 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
495 struct v9fs_session_info *v9ses;
496
497 spin_lock(&v9fs_sessionlist_lock);
498 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
499 if (v9ses->cachetag) {
500 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
501 if (n < 0) {
502 count = n;
503 break;
504 }
505
506 count += n;
507 limit -= n;
508 }
509 }
510
511 spin_unlock(&v9fs_sessionlist_lock);
512 return count;
513}
514
515static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
516#endif /* CONFIG_9P_FSCACHE */
517
518static struct attribute *v9fs_attrs[] = {
519#ifdef CONFIG_9P_FSCACHE
520 &v9fs_attr_cache.attr,
521#endif
522 NULL,
523};
524
525static struct attribute_group v9fs_attr_group = {
526 .attrs = v9fs_attrs,
527};
528
529/**
530 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
531 *
532 */
533
534static int __init v9fs_sysfs_init(void)
535{
536 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
537 if (!v9fs_kobj)
538 return -ENOMEM;
539
540 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
541 kobject_put(v9fs_kobj);
542 return -ENOMEM;
543 }
544
545 return 0;
546}
547
548/**
549 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
550 *
551 */
552
553static void v9fs_sysfs_cleanup(void)
554{
555 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
556 kobject_put(v9fs_kobj);
557}
558
559static void v9fs_inode_init_once(void *foo)
560{
561 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
562#ifdef CONFIG_9P_FSCACHE
563 v9inode->fscache = NULL;
564#endif
565 memset(&v9inode->qid, 0, sizeof(v9inode->qid));
566 inode_init_once(&v9inode->vfs_inode);
567}
568
569/**
570 * v9fs_init_inode_cache - initialize a cache for 9P
571 * Returns 0 on success.
572 */
573static int v9fs_init_inode_cache(void)
574{
575 v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
576 sizeof(struct v9fs_inode),
577 0, (SLAB_RECLAIM_ACCOUNT|
578 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
579 v9fs_inode_init_once);
580 if (!v9fs_inode_cache)
581 return -ENOMEM;
582
583 return 0;
584}
585
586/**
587 * v9fs_destroy_inode_cache - destroy the cache of 9P inode
588 *
589 */
590static void v9fs_destroy_inode_cache(void)
591{
592 /*
593 * Make sure all delayed rcu free inodes are flushed before we
594 * destroy cache.
595 */
596 rcu_barrier();
597 kmem_cache_destroy(v9fs_inode_cache);
598}
599
600static int v9fs_cache_register(void)
601{
602 int ret;
603 ret = v9fs_init_inode_cache();
604 if (ret < 0)
605 return ret;
606#ifdef CONFIG_9P_FSCACHE
607 ret = fscache_register_netfs(&v9fs_cache_netfs);
608 if (ret < 0)
609 v9fs_destroy_inode_cache();
610#endif
611 return ret;
612}
613
614static void v9fs_cache_unregister(void)
615{
616 v9fs_destroy_inode_cache();
617#ifdef CONFIG_9P_FSCACHE
618 fscache_unregister_netfs(&v9fs_cache_netfs);
619#endif
620}
621
622/**
623 * init_v9fs - Initialize module
624 *
625 */
626
627static int __init init_v9fs(void)
628{
629 int err;
630 pr_info("Installing v9fs 9p2000 file system support\n");
631 /* TODO: Setup list of registered trasnport modules */
632
633 err = v9fs_cache_register();
634 if (err < 0) {
635 pr_err("Failed to register v9fs for caching\n");
636 return err;
637 }
638
639 err = v9fs_sysfs_init();
640 if (err < 0) {
641 pr_err("Failed to register with sysfs\n");
642 goto out_cache;
643 }
644 err = register_filesystem(&v9fs_fs_type);
645 if (err < 0) {
646 pr_err("Failed to register filesystem\n");
647 goto out_sysfs_cleanup;
648 }
649
650 return 0;
651
652out_sysfs_cleanup:
653 v9fs_sysfs_cleanup();
654
655out_cache:
656 v9fs_cache_unregister();
657
658 return err;
659}
660
661/**
662 * exit_v9fs - shutdown module
663 *
664 */
665
666static void __exit exit_v9fs(void)
667{
668 v9fs_sysfs_cleanup();
669 v9fs_cache_unregister();
670 unregister_filesystem(&v9fs_fs_type);
671}
672
673module_init(init_v9fs)
674module_exit(exit_v9fs)
675
676MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
677MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
678MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
679MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contains functions assisting in mapping VFS to 9P2000
4 *
5 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/module.h>
12#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/sched.h>
15#include <linux/cred.h>
16#include <linux/parser.h>
17#include <linux/slab.h>
18#include <linux/seq_file.h>
19#include <net/9p/9p.h>
20#include <net/9p/client.h>
21#include <net/9p/transport.h>
22#include "v9fs.h"
23#include "v9fs_vfs.h"
24#include "cache.h"
25
26static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
27static LIST_HEAD(v9fs_sessionlist);
28struct kmem_cache *v9fs_inode_cache;
29
30/*
31 * Option Parsing (code inspired by NFS code)
32 * NOTE: each transport will parse its own options
33 */
34
35enum {
36 /* Options that take integer arguments */
37 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
38 /* String options */
39 Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
40 /* Options that take no arguments */
41 Opt_nodevmap,
42 /* Cache options */
43 Opt_cache_loose, Opt_fscache, Opt_mmap,
44 /* Access options */
45 Opt_access, Opt_posixacl,
46 /* Lock timeout option */
47 Opt_locktimeout,
48 /* Error token */
49 Opt_err
50};
51
52static const match_table_t tokens = {
53 {Opt_debug, "debug=%x"},
54 {Opt_dfltuid, "dfltuid=%u"},
55 {Opt_dfltgid, "dfltgid=%u"},
56 {Opt_afid, "afid=%u"},
57 {Opt_uname, "uname=%s"},
58 {Opt_remotename, "aname=%s"},
59 {Opt_nodevmap, "nodevmap"},
60 {Opt_cache, "cache=%s"},
61 {Opt_cache_loose, "loose"},
62 {Opt_fscache, "fscache"},
63 {Opt_mmap, "mmap"},
64 {Opt_cachetag, "cachetag=%s"},
65 {Opt_access, "access=%s"},
66 {Opt_posixacl, "posixacl"},
67 {Opt_locktimeout, "locktimeout=%u"},
68 {Opt_err, NULL}
69};
70
71static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
72 [CACHE_NONE] = "none",
73 [CACHE_MMAP] = "mmap",
74 [CACHE_LOOSE] = "loose",
75 [CACHE_FSCACHE] = "fscache",
76};
77
78/* Interpret mount options for cache mode */
79static int get_cache_mode(char *s)
80{
81 int version = -EINVAL;
82
83 if (!strcmp(s, "loose")) {
84 version = CACHE_LOOSE;
85 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
86 } else if (!strcmp(s, "fscache")) {
87 version = CACHE_FSCACHE;
88 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
89 } else if (!strcmp(s, "mmap")) {
90 version = CACHE_MMAP;
91 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
92 } else if (!strcmp(s, "none")) {
93 version = CACHE_NONE;
94 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
95 } else
96 pr_info("Unknown Cache mode %s\n", s);
97 return version;
98}
99
100/*
101 * Display the mount options in /proc/mounts.
102 */
103int v9fs_show_options(struct seq_file *m, struct dentry *root)
104{
105 struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
106
107 if (v9ses->debug)
108 seq_printf(m, ",debug=%x", v9ses->debug);
109 if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
110 seq_printf(m, ",dfltuid=%u",
111 from_kuid_munged(&init_user_ns, v9ses->dfltuid));
112 if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
113 seq_printf(m, ",dfltgid=%u",
114 from_kgid_munged(&init_user_ns, v9ses->dfltgid));
115 if (v9ses->afid != ~0)
116 seq_printf(m, ",afid=%u", v9ses->afid);
117 if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
118 seq_printf(m, ",uname=%s", v9ses->uname);
119 if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
120 seq_printf(m, ",aname=%s", v9ses->aname);
121 if (v9ses->nodev)
122 seq_puts(m, ",nodevmap");
123 if (v9ses->cache)
124 seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
125#ifdef CONFIG_9P_FSCACHE
126 if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
127 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
128#endif
129
130 switch (v9ses->flags & V9FS_ACCESS_MASK) {
131 case V9FS_ACCESS_USER:
132 seq_puts(m, ",access=user");
133 break;
134 case V9FS_ACCESS_ANY:
135 seq_puts(m, ",access=any");
136 break;
137 case V9FS_ACCESS_CLIENT:
138 seq_puts(m, ",access=client");
139 break;
140 case V9FS_ACCESS_SINGLE:
141 seq_printf(m, ",access=%u",
142 from_kuid_munged(&init_user_ns, v9ses->uid));
143 break;
144 }
145
146 if (v9ses->flags & V9FS_POSIX_ACL)
147 seq_puts(m, ",posixacl");
148
149 return p9_show_client_options(m, v9ses->clnt);
150}
151
152/**
153 * v9fs_parse_options - parse mount options into session structure
154 * @v9ses: existing v9fs session information
155 * @opts: The mount option string
156 *
157 * Return 0 upon success, -ERRNO upon failure.
158 */
159
160static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
161{
162 char *options, *tmp_options;
163 substring_t args[MAX_OPT_ARGS];
164 char *p;
165 int option = 0;
166 char *s;
167 int ret = 0;
168
169 /* setup defaults */
170 v9ses->afid = ~0;
171 v9ses->debug = 0;
172 v9ses->cache = CACHE_NONE;
173#ifdef CONFIG_9P_FSCACHE
174 v9ses->cachetag = NULL;
175#endif
176 v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
177
178 if (!opts)
179 return 0;
180
181 tmp_options = kstrdup(opts, GFP_KERNEL);
182 if (!tmp_options) {
183 ret = -ENOMEM;
184 goto fail_option_alloc;
185 }
186 options = tmp_options;
187
188 while ((p = strsep(&options, ",")) != NULL) {
189 int token, r;
190
191 if (!*p)
192 continue;
193
194 token = match_token(p, tokens, args);
195 switch (token) {
196 case Opt_debug:
197 r = match_int(&args[0], &option);
198 if (r < 0) {
199 p9_debug(P9_DEBUG_ERROR,
200 "integer field, but no integer?\n");
201 ret = r;
202 } else {
203 v9ses->debug = option;
204#ifdef CONFIG_NET_9P_DEBUG
205 p9_debug_level = option;
206#endif
207 }
208 break;
209
210 case Opt_dfltuid:
211 r = match_int(&args[0], &option);
212 if (r < 0) {
213 p9_debug(P9_DEBUG_ERROR,
214 "integer field, but no integer?\n");
215 ret = r;
216 continue;
217 }
218 v9ses->dfltuid = make_kuid(current_user_ns(), option);
219 if (!uid_valid(v9ses->dfltuid)) {
220 p9_debug(P9_DEBUG_ERROR,
221 "uid field, but not a uid?\n");
222 ret = -EINVAL;
223 }
224 break;
225 case Opt_dfltgid:
226 r = match_int(&args[0], &option);
227 if (r < 0) {
228 p9_debug(P9_DEBUG_ERROR,
229 "integer field, but no integer?\n");
230 ret = r;
231 continue;
232 }
233 v9ses->dfltgid = make_kgid(current_user_ns(), option);
234 if (!gid_valid(v9ses->dfltgid)) {
235 p9_debug(P9_DEBUG_ERROR,
236 "gid field, but not a gid?\n");
237 ret = -EINVAL;
238 }
239 break;
240 case Opt_afid:
241 r = match_int(&args[0], &option);
242 if (r < 0) {
243 p9_debug(P9_DEBUG_ERROR,
244 "integer field, but no integer?\n");
245 ret = r;
246 } else {
247 v9ses->afid = option;
248 }
249 break;
250 case Opt_uname:
251 kfree(v9ses->uname);
252 v9ses->uname = match_strdup(&args[0]);
253 if (!v9ses->uname) {
254 ret = -ENOMEM;
255 goto free_and_return;
256 }
257 break;
258 case Opt_remotename:
259 kfree(v9ses->aname);
260 v9ses->aname = match_strdup(&args[0]);
261 if (!v9ses->aname) {
262 ret = -ENOMEM;
263 goto free_and_return;
264 }
265 break;
266 case Opt_nodevmap:
267 v9ses->nodev = 1;
268 break;
269 case Opt_cache_loose:
270 v9ses->cache = CACHE_LOOSE;
271 break;
272 case Opt_fscache:
273 v9ses->cache = CACHE_FSCACHE;
274 break;
275 case Opt_mmap:
276 v9ses->cache = CACHE_MMAP;
277 break;
278 case Opt_cachetag:
279#ifdef CONFIG_9P_FSCACHE
280 kfree(v9ses->cachetag);
281 v9ses->cachetag = match_strdup(&args[0]);
282 if (!v9ses->cachetag) {
283 ret = -ENOMEM;
284 goto free_and_return;
285 }
286#endif
287 break;
288 case Opt_cache:
289 s = match_strdup(&args[0]);
290 if (!s) {
291 ret = -ENOMEM;
292 p9_debug(P9_DEBUG_ERROR,
293 "problem allocating copy of cache arg\n");
294 goto free_and_return;
295 }
296 r = get_cache_mode(s);
297 if (r < 0)
298 ret = r;
299 else
300 v9ses->cache = r;
301
302 kfree(s);
303 break;
304
305 case Opt_access:
306 s = match_strdup(&args[0]);
307 if (!s) {
308 ret = -ENOMEM;
309 p9_debug(P9_DEBUG_ERROR,
310 "problem allocating copy of access arg\n");
311 goto free_and_return;
312 }
313
314 v9ses->flags &= ~V9FS_ACCESS_MASK;
315 if (strcmp(s, "user") == 0)
316 v9ses->flags |= V9FS_ACCESS_USER;
317 else if (strcmp(s, "any") == 0)
318 v9ses->flags |= V9FS_ACCESS_ANY;
319 else if (strcmp(s, "client") == 0) {
320 v9ses->flags |= V9FS_ACCESS_CLIENT;
321 } else {
322 uid_t uid;
323
324 v9ses->flags |= V9FS_ACCESS_SINGLE;
325 r = kstrtouint(s, 10, &uid);
326 if (r) {
327 ret = r;
328 pr_info("Unknown access argument %s: %d\n",
329 s, r);
330 kfree(s);
331 continue;
332 }
333 v9ses->uid = make_kuid(current_user_ns(), uid);
334 if (!uid_valid(v9ses->uid)) {
335 ret = -EINVAL;
336 pr_info("Unknown uid %s\n", s);
337 }
338 }
339
340 kfree(s);
341 break;
342
343 case Opt_posixacl:
344#ifdef CONFIG_9P_FS_POSIX_ACL
345 v9ses->flags |= V9FS_POSIX_ACL;
346#else
347 p9_debug(P9_DEBUG_ERROR,
348 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
349#endif
350 break;
351
352 case Opt_locktimeout:
353 r = match_int(&args[0], &option);
354 if (r < 0) {
355 p9_debug(P9_DEBUG_ERROR,
356 "integer field, but no integer?\n");
357 ret = r;
358 continue;
359 }
360 if (option < 1) {
361 p9_debug(P9_DEBUG_ERROR,
362 "locktimeout must be a greater than zero integer.\n");
363 ret = -EINVAL;
364 continue;
365 }
366 v9ses->session_lock_timeout = (long)option * HZ;
367 break;
368
369 default:
370 continue;
371 }
372 }
373
374free_and_return:
375 kfree(tmp_options);
376fail_option_alloc:
377 return ret;
378}
379
380/**
381 * v9fs_session_init - initialize session
382 * @v9ses: session information structure
383 * @dev_name: device being mounted
384 * @data: options
385 *
386 */
387
388struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
389 const char *dev_name, char *data)
390{
391 struct p9_fid *fid;
392 int rc = -ENOMEM;
393
394 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
395 if (!v9ses->uname)
396 goto err_names;
397
398 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
399 if (!v9ses->aname)
400 goto err_names;
401 init_rwsem(&v9ses->rename_sem);
402
403 v9ses->uid = INVALID_UID;
404 v9ses->dfltuid = V9FS_DEFUID;
405 v9ses->dfltgid = V9FS_DEFGID;
406
407 v9ses->clnt = p9_client_create(dev_name, data);
408 if (IS_ERR(v9ses->clnt)) {
409 rc = PTR_ERR(v9ses->clnt);
410 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
411 goto err_names;
412 }
413
414 v9ses->flags = V9FS_ACCESS_USER;
415
416 if (p9_is_proto_dotl(v9ses->clnt)) {
417 v9ses->flags = V9FS_ACCESS_CLIENT;
418 v9ses->flags |= V9FS_PROTO_2000L;
419 } else if (p9_is_proto_dotu(v9ses->clnt)) {
420 v9ses->flags |= V9FS_PROTO_2000U;
421 }
422
423 rc = v9fs_parse_options(v9ses, data);
424 if (rc < 0)
425 goto err_clnt;
426
427 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
428
429 if (!v9fs_proto_dotl(v9ses) &&
430 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
431 /*
432 * We support ACCESS_CLIENT only for dotl.
433 * Fall back to ACCESS_USER
434 */
435 v9ses->flags &= ~V9FS_ACCESS_MASK;
436 v9ses->flags |= V9FS_ACCESS_USER;
437 }
438 /*FIXME !! */
439 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
440 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
441 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
442
443 v9ses->flags &= ~V9FS_ACCESS_MASK;
444 v9ses->flags |= V9FS_ACCESS_ANY;
445 v9ses->uid = INVALID_UID;
446 }
447 if (!v9fs_proto_dotl(v9ses) ||
448 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
449 /*
450 * We support ACL checks on clinet only if the protocol is
451 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
452 */
453 v9ses->flags &= ~V9FS_ACL_MASK;
454 }
455
456 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
457 v9ses->aname);
458 if (IS_ERR(fid)) {
459 rc = PTR_ERR(fid);
460 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
461 goto err_clnt;
462 }
463
464 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
465 fid->uid = v9ses->uid;
466 else
467 fid->uid = INVALID_UID;
468
469#ifdef CONFIG_9P_FSCACHE
470 /* register the session for caching */
471 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
472 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
473 if (rc < 0)
474 goto err_clnt;
475 }
476#endif
477 spin_lock(&v9fs_sessionlist_lock);
478 list_add(&v9ses->slist, &v9fs_sessionlist);
479 spin_unlock(&v9fs_sessionlist_lock);
480
481 return fid;
482
483err_clnt:
484#ifdef CONFIG_9P_FSCACHE
485 kfree(v9ses->cachetag);
486#endif
487 p9_client_destroy(v9ses->clnt);
488err_names:
489 kfree(v9ses->uname);
490 kfree(v9ses->aname);
491 return ERR_PTR(rc);
492}
493
494/**
495 * v9fs_session_close - shutdown a session
496 * @v9ses: session information structure
497 *
498 */
499
500void v9fs_session_close(struct v9fs_session_info *v9ses)
501{
502 if (v9ses->clnt) {
503 p9_client_destroy(v9ses->clnt);
504 v9ses->clnt = NULL;
505 }
506
507#ifdef CONFIG_9P_FSCACHE
508 fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);
509 kfree(v9ses->cachetag);
510#endif
511 kfree(v9ses->uname);
512 kfree(v9ses->aname);
513
514 spin_lock(&v9fs_sessionlist_lock);
515 list_del(&v9ses->slist);
516 spin_unlock(&v9fs_sessionlist_lock);
517}
518
519/**
520 * v9fs_session_cancel - terminate a session
521 * @v9ses: session to terminate
522 *
523 * mark transport as disconnected and cancel all pending requests.
524 */
525
526void v9fs_session_cancel(struct v9fs_session_info *v9ses)
527{
528 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
529 p9_client_disconnect(v9ses->clnt);
530}
531
532/**
533 * v9fs_session_begin_cancel - Begin terminate of a session
534 * @v9ses: session to terminate
535 *
536 * After this call we don't allow any request other than clunk.
537 */
538
539void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
540{
541 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
542 p9_client_begin_disconnect(v9ses->clnt);
543}
544
545extern int v9fs_error_init(void);
546
547static struct kobject *v9fs_kobj;
548
549#ifdef CONFIG_9P_FSCACHE
550/*
551 * List caches associated with a session
552 */
553static ssize_t caches_show(struct kobject *kobj,
554 struct kobj_attribute *attr,
555 char *buf)
556{
557 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
558 struct v9fs_session_info *v9ses;
559
560 spin_lock(&v9fs_sessionlist_lock);
561 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
562 if (v9ses->cachetag) {
563 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
564 if (n < 0) {
565 count = n;
566 break;
567 }
568
569 count += n;
570 limit -= n;
571 }
572 }
573
574 spin_unlock(&v9fs_sessionlist_lock);
575 return count;
576}
577
578static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
579#endif /* CONFIG_9P_FSCACHE */
580
581static struct attribute *v9fs_attrs[] = {
582#ifdef CONFIG_9P_FSCACHE
583 &v9fs_attr_cache.attr,
584#endif
585 NULL,
586};
587
588static const struct attribute_group v9fs_attr_group = {
589 .attrs = v9fs_attrs,
590};
591
592/**
593 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
594 *
595 */
596
597static int __init v9fs_sysfs_init(void)
598{
599 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
600 if (!v9fs_kobj)
601 return -ENOMEM;
602
603 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
604 kobject_put(v9fs_kobj);
605 return -ENOMEM;
606 }
607
608 return 0;
609}
610
611/**
612 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
613 *
614 */
615
616static void v9fs_sysfs_cleanup(void)
617{
618 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
619 kobject_put(v9fs_kobj);
620}
621
622static void v9fs_inode_init_once(void *foo)
623{
624 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
625
626 memset(&v9inode->qid, 0, sizeof(v9inode->qid));
627 inode_init_once(&v9inode->netfs.inode);
628}
629
630/**
631 * v9fs_init_inode_cache - initialize a cache for 9P
632 * Returns 0 on success.
633 */
634static int v9fs_init_inode_cache(void)
635{
636 v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
637 sizeof(struct v9fs_inode),
638 0, (SLAB_RECLAIM_ACCOUNT|
639 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
640 v9fs_inode_init_once);
641 if (!v9fs_inode_cache)
642 return -ENOMEM;
643
644 return 0;
645}
646
647/**
648 * v9fs_destroy_inode_cache - destroy the cache of 9P inode
649 *
650 */
651static void v9fs_destroy_inode_cache(void)
652{
653 /*
654 * Make sure all delayed rcu free inodes are flushed before we
655 * destroy cache.
656 */
657 rcu_barrier();
658 kmem_cache_destroy(v9fs_inode_cache);
659}
660
661static int v9fs_cache_register(void)
662{
663 int ret;
664
665 ret = v9fs_init_inode_cache();
666 if (ret < 0)
667 return ret;
668 return ret;
669}
670
671static void v9fs_cache_unregister(void)
672{
673 v9fs_destroy_inode_cache();
674}
675
676/**
677 * init_v9fs - Initialize module
678 *
679 */
680
681static int __init init_v9fs(void)
682{
683 int err;
684
685 pr_info("Installing v9fs 9p2000 file system support\n");
686 /* TODO: Setup list of registered trasnport modules */
687
688 err = v9fs_cache_register();
689 if (err < 0) {
690 pr_err("Failed to register v9fs for caching\n");
691 return err;
692 }
693
694 err = v9fs_sysfs_init();
695 if (err < 0) {
696 pr_err("Failed to register with sysfs\n");
697 goto out_cache;
698 }
699 err = register_filesystem(&v9fs_fs_type);
700 if (err < 0) {
701 pr_err("Failed to register filesystem\n");
702 goto out_sysfs_cleanup;
703 }
704
705 return 0;
706
707out_sysfs_cleanup:
708 v9fs_sysfs_cleanup();
709
710out_cache:
711 v9fs_cache_unregister();
712
713 return err;
714}
715
716/**
717 * exit_v9fs - shutdown module
718 *
719 */
720
721static void __exit exit_v9fs(void)
722{
723 v9fs_sysfs_cleanup();
724 v9fs_cache_unregister();
725 unregister_filesystem(&v9fs_fs_type);
726}
727
728module_init(init_v9fs)
729module_exit(exit_v9fs)
730
731MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
732MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
733MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
734MODULE_LICENSE("GPL");