ARM: tegra: pm375 : Enable utmi1
[linux-3.10.git] / fs / 9p / v9fs.c
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
42 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
43 static LIST_HEAD(v9fs_sessionlist);
44 struct 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
51 enum {
52         /* Options that take integer arguments */
53         Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
54         /* String options */
55         Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
56         /* Options that take no arguments */
57         Opt_nodevmap,
58         /* Cache options */
59         Opt_cache_loose, Opt_fscache,
60         /* Access options */
61         Opt_access, Opt_posixacl,
62         /* Error token */
63         Opt_err
64 };
65
66 static 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_cachetag, "cachetag=%s"},
78         {Opt_access, "access=%s"},
79         {Opt_posixacl, "posixacl"},
80         {Opt_err, NULL}
81 };
82
83 /* Interpret mount options for cache mode */
84 static int get_cache_mode(char *s)
85 {
86         int version = -EINVAL;
87
88         if (!strcmp(s, "loose")) {
89                 version = CACHE_LOOSE;
90                 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
91         } else if (!strcmp(s, "fscache")) {
92                 version = CACHE_FSCACHE;
93                 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
94         } else if (!strcmp(s, "none")) {
95                 version = CACHE_NONE;
96                 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
97         } else
98                 pr_info("Unknown Cache mode %s\n", s);
99         return version;
100 }
101
102 /**
103  * v9fs_parse_options - parse mount options into session structure
104  * @v9ses: existing v9fs session information
105  *
106  * Return 0 upon success, -ERRNO upon failure.
107  */
108
109 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
110 {
111         char *options, *tmp_options;
112         substring_t args[MAX_OPT_ARGS];
113         char *p;
114         int option = 0;
115         char *s, *e;
116         int ret = 0;
117
118         /* setup defaults */
119         v9ses->afid = ~0;
120         v9ses->debug = 0;
121         v9ses->cache = CACHE_NONE;
122 #ifdef CONFIG_9P_FSCACHE
123         v9ses->cachetag = NULL;
124 #endif
125
126         if (!opts)
127                 return 0;
128
129         tmp_options = kstrdup(opts, GFP_KERNEL);
130         if (!tmp_options) {
131                 ret = -ENOMEM;
132                 goto fail_option_alloc;
133         }
134         options = tmp_options;
135
136         while ((p = strsep(&options, ",")) != NULL) {
137                 int token, r;
138                 if (!*p)
139                         continue;
140                 token = match_token(p, tokens, args);
141                 switch (token) {
142                 case Opt_debug:
143                         r = match_int(&args[0], &option);
144                         if (r < 0) {
145                                 p9_debug(P9_DEBUG_ERROR,
146                                          "integer field, but no integer?\n");
147                                 ret = r;
148                                 continue;
149                         }
150                         v9ses->debug = option;
151 #ifdef CONFIG_NET_9P_DEBUG
152                         p9_debug_level = option;
153 #endif
154                         break;
155
156                 case Opt_dfltuid:
157                         r = match_int(&args[0], &option);
158                         if (r < 0) {
159                                 p9_debug(P9_DEBUG_ERROR,
160                                          "integer field, but no integer?\n");
161                                 ret = r;
162                                 continue;
163                         }
164                         v9ses->dfltuid = make_kuid(current_user_ns(), option);
165                         if (!uid_valid(v9ses->dfltuid)) {
166                                 p9_debug(P9_DEBUG_ERROR,
167                                          "uid field, but not a uid?\n");
168                                 ret = -EINVAL;
169                                 continue;
170                         }
171                         break;
172                 case Opt_dfltgid:
173                         r = match_int(&args[0], &option);
174                         if (r < 0) {
175                                 p9_debug(P9_DEBUG_ERROR,
176                                          "integer field, but no integer?\n");
177                                 ret = r;
178                                 continue;
179                         }
180                         v9ses->dfltgid = make_kgid(current_user_ns(), option);
181                         if (!gid_valid(v9ses->dfltgid)) {
182                                 p9_debug(P9_DEBUG_ERROR,
183                                          "gid field, but not a gid?\n");
184                                 ret = -EINVAL;
185                                 continue;
186                         }
187                         break;
188                 case Opt_afid:
189                         r = match_int(&args[0], &option);
190                         if (r < 0) {
191                                 p9_debug(P9_DEBUG_ERROR,
192                                          "integer field, but no integer?\n");
193                                 ret = r;
194                                 continue;
195                         }
196                         v9ses->afid = option;
197                         break;
198                 case Opt_uname:
199                         kfree(v9ses->uname);
200                         v9ses->uname = match_strdup(&args[0]);
201                         if (!v9ses->uname) {
202                                 ret = -ENOMEM;
203                                 goto free_and_return;
204                         }
205                         break;
206                 case Opt_remotename:
207                         kfree(v9ses->aname);
208                         v9ses->aname = match_strdup(&args[0]);
209                         if (!v9ses->aname) {
210                                 ret = -ENOMEM;
211                                 goto free_and_return;
212                         }
213                         break;
214                 case Opt_nodevmap:
215                         v9ses->nodev = 1;
216                         break;
217                 case Opt_cache_loose:
218                         v9ses->cache = CACHE_LOOSE;
219                         break;
220                 case Opt_fscache:
221                         v9ses->cache = CACHE_FSCACHE;
222                         break;
223                 case Opt_cachetag:
224 #ifdef CONFIG_9P_FSCACHE
225                         v9ses->cachetag = match_strdup(&args[0]);
226 #endif
227                         break;
228                 case Opt_cache:
229                         s = match_strdup(&args[0]);
230                         if (!s) {
231                                 ret = -ENOMEM;
232                                 p9_debug(P9_DEBUG_ERROR,
233                                          "problem allocating copy of cache arg\n");
234                                 goto free_and_return;
235                         }
236                         ret = get_cache_mode(s);
237                         if (ret == -EINVAL) {
238                                 kfree(s);
239                                 goto free_and_return;
240                         }
241
242                         v9ses->cache = ret;
243                         kfree(s);
244                         break;
245
246                 case Opt_access:
247                         s = match_strdup(&args[0]);
248                         if (!s) {
249                                 ret = -ENOMEM;
250                                 p9_debug(P9_DEBUG_ERROR,
251                                          "problem allocating copy of access arg\n");
252                                 goto free_and_return;
253                         }
254
255                         v9ses->flags &= ~V9FS_ACCESS_MASK;
256                         if (strcmp(s, "user") == 0)
257                                 v9ses->flags |= V9FS_ACCESS_USER;
258                         else if (strcmp(s, "any") == 0)
259                                 v9ses->flags |= V9FS_ACCESS_ANY;
260                         else if (strcmp(s, "client") == 0) {
261                                 v9ses->flags |= V9FS_ACCESS_CLIENT;
262                         } else {
263                                 uid_t uid;
264                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
265                                 uid = simple_strtoul(s, &e, 10);
266                                 if (*e != '\0') {
267                                         ret = -EINVAL;
268                                         pr_info("Unknown access argument %s\n",
269                                                 s);
270                                         kfree(s);
271                                         goto free_and_return;
272                                 }
273                                 v9ses->uid = make_kuid(current_user_ns(), uid);
274                                 if (!uid_valid(v9ses->uid)) {
275                                         ret = -EINVAL;
276                                         pr_info("Uknown uid %s\n", s);
277                                         kfree(s);
278                                         goto free_and_return;
279                                 }
280                         }
281
282                         kfree(s);
283                         break;
284
285                 case Opt_posixacl:
286 #ifdef CONFIG_9P_FS_POSIX_ACL
287                         v9ses->flags |= V9FS_POSIX_ACL;
288 #else
289                         p9_debug(P9_DEBUG_ERROR,
290                                  "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
291 #endif
292                         break;
293
294                 default:
295                         continue;
296                 }
297         }
298
299 free_and_return:
300         kfree(tmp_options);
301 fail_option_alloc:
302         return ret;
303 }
304
305 /**
306  * v9fs_session_init - initialize session
307  * @v9ses: session information structure
308  * @dev_name: device being mounted
309  * @data: options
310  *
311  */
312
313 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
314                   const char *dev_name, char *data)
315 {
316         int retval = -EINVAL;
317         struct p9_fid *fid;
318         int rc;
319
320         v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
321         if (!v9ses->uname)
322                 return ERR_PTR(-ENOMEM);
323
324         v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
325         if (!v9ses->aname) {
326                 kfree(v9ses->uname);
327                 return ERR_PTR(-ENOMEM);
328         }
329         init_rwsem(&v9ses->rename_sem);
330
331         rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
332         if (rc) {
333                 kfree(v9ses->aname);
334                 kfree(v9ses->uname);
335                 return ERR_PTR(rc);
336         }
337
338         spin_lock(&v9fs_sessionlist_lock);
339         list_add(&v9ses->slist, &v9fs_sessionlist);
340         spin_unlock(&v9fs_sessionlist_lock);
341
342         v9ses->uid = INVALID_UID;
343         v9ses->dfltuid = V9FS_DEFUID;
344         v9ses->dfltgid = V9FS_DEFGID;
345
346         v9ses->clnt = p9_client_create(dev_name, data);
347         if (IS_ERR(v9ses->clnt)) {
348                 retval = PTR_ERR(v9ses->clnt);
349                 v9ses->clnt = NULL;
350                 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
351                 goto error;
352         }
353
354         v9ses->flags = V9FS_ACCESS_USER;
355
356         if (p9_is_proto_dotl(v9ses->clnt)) {
357                 v9ses->flags = V9FS_ACCESS_CLIENT;
358                 v9ses->flags |= V9FS_PROTO_2000L;
359         } else if (p9_is_proto_dotu(v9ses->clnt)) {
360                 v9ses->flags |= V9FS_PROTO_2000U;
361         }
362
363         rc = v9fs_parse_options(v9ses, data);
364         if (rc < 0) {
365                 retval = rc;
366                 goto error;
367         }
368
369         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
370
371         if (!v9fs_proto_dotl(v9ses) &&
372             ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
373                 /*
374                  * We support ACCESS_CLIENT only for dotl.
375                  * Fall back to ACCESS_USER
376                  */
377                 v9ses->flags &= ~V9FS_ACCESS_MASK;
378                 v9ses->flags |= V9FS_ACCESS_USER;
379         }
380         /*FIXME !! */
381         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
382         if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
383                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
384
385                 v9ses->flags &= ~V9FS_ACCESS_MASK;
386                 v9ses->flags |= V9FS_ACCESS_ANY;
387                 v9ses->uid = INVALID_UID;
388         }
389         if (!v9fs_proto_dotl(v9ses) ||
390                 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
391                 /*
392                  * We support ACL checks on clinet only if the protocol is
393                  * 9P2000.L and access is V9FS_ACCESS_CLIENT.
394                  */
395                 v9ses->flags &= ~V9FS_ACL_MASK;
396         }
397
398         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
399                                                         v9ses->aname);
400         if (IS_ERR(fid)) {
401                 retval = PTR_ERR(fid);
402                 fid = NULL;
403                 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
404                 goto error;
405         }
406
407         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
408                 fid->uid = v9ses->uid;
409         else
410                 fid->uid = INVALID_UID;
411
412 #ifdef CONFIG_9P_FSCACHE
413         /* register the session for caching */
414         v9fs_cache_session_get_cookie(v9ses);
415 #endif
416
417         return fid;
418
419 error:
420         bdi_destroy(&v9ses->bdi);
421         return ERR_PTR(retval);
422 }
423
424 /**
425  * v9fs_session_close - shutdown a session
426  * @v9ses: session information structure
427  *
428  */
429
430 void v9fs_session_close(struct v9fs_session_info *v9ses)
431 {
432         if (v9ses->clnt) {
433                 p9_client_destroy(v9ses->clnt);
434                 v9ses->clnt = NULL;
435         }
436
437 #ifdef CONFIG_9P_FSCACHE
438         if (v9ses->fscache) {
439                 v9fs_cache_session_put_cookie(v9ses);
440                 kfree(v9ses->cachetag);
441         }
442 #endif
443         kfree(v9ses->uname);
444         kfree(v9ses->aname);
445
446         bdi_destroy(&v9ses->bdi);
447
448         spin_lock(&v9fs_sessionlist_lock);
449         list_del(&v9ses->slist);
450         spin_unlock(&v9fs_sessionlist_lock);
451 }
452
453 /**
454  * v9fs_session_cancel - terminate a session
455  * @v9ses: session to terminate
456  *
457  * mark transport as disconnected and cancel all pending requests.
458  */
459
460 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
461         p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
462         p9_client_disconnect(v9ses->clnt);
463 }
464
465 /**
466  * v9fs_session_begin_cancel - Begin terminate of a session
467  * @v9ses: session to terminate
468  *
469  * After this call we don't allow any request other than clunk.
470  */
471
472 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
473 {
474         p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
475         p9_client_begin_disconnect(v9ses->clnt);
476 }
477
478 extern int v9fs_error_init(void);
479
480 static struct kobject *v9fs_kobj;
481
482 #ifdef CONFIG_9P_FSCACHE
483 /**
484  * caches_show - list caches associated with a session
485  *
486  * Returns the size of buffer written.
487  */
488
489 static ssize_t caches_show(struct kobject *kobj,
490                            struct kobj_attribute *attr,
491                            char *buf)
492 {
493         ssize_t n = 0, count = 0, limit = PAGE_SIZE;
494         struct v9fs_session_info *v9ses;
495
496         spin_lock(&v9fs_sessionlist_lock);
497         list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
498                 if (v9ses->cachetag) {
499                         n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
500                         if (n < 0) {
501                                 count = n;
502                                 break;
503                         }
504
505                         count += n;
506                         limit -= n;
507                 }
508         }
509
510         spin_unlock(&v9fs_sessionlist_lock);
511         return count;
512 }
513
514 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
515 #endif /* CONFIG_9P_FSCACHE */
516
517 static struct attribute *v9fs_attrs[] = {
518 #ifdef CONFIG_9P_FSCACHE
519         &v9fs_attr_cache.attr,
520 #endif
521         NULL,
522 };
523
524 static struct attribute_group v9fs_attr_group = {
525         .attrs = v9fs_attrs,
526 };
527
528 /**
529  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
530  *
531  */
532
533 static int v9fs_sysfs_init(void)
534 {
535         v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
536         if (!v9fs_kobj)
537                 return -ENOMEM;
538
539         if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
540                 kobject_put(v9fs_kobj);
541                 return -ENOMEM;
542         }
543
544         return 0;
545 }
546
547 /**
548  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
549  *
550  */
551
552 static void v9fs_sysfs_cleanup(void)
553 {
554         sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
555         kobject_put(v9fs_kobj);
556 }
557
558 static void v9fs_inode_init_once(void *foo)
559 {
560         struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
561 #ifdef CONFIG_9P_FSCACHE
562         v9inode->fscache = NULL;
563 #endif
564         memset(&v9inode->qid, 0, sizeof(v9inode->qid));
565         inode_init_once(&v9inode->vfs_inode);
566 }
567
568 /**
569  * v9fs_init_inode_cache - initialize a cache for 9P
570  * Returns 0 on success.
571  */
572 static int v9fs_init_inode_cache(void)
573 {
574         v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
575                                           sizeof(struct v9fs_inode),
576                                           0, (SLAB_RECLAIM_ACCOUNT|
577                                               SLAB_MEM_SPREAD),
578                                           v9fs_inode_init_once);
579         if (!v9fs_inode_cache)
580                 return -ENOMEM;
581
582         return 0;
583 }
584
585 /**
586  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
587  *
588  */
589 static void v9fs_destroy_inode_cache(void)
590 {
591         /*
592          * Make sure all delayed rcu free inodes are flushed before we
593          * destroy cache.
594          */
595         rcu_barrier();
596         kmem_cache_destroy(v9fs_inode_cache);
597 }
598
599 static int v9fs_cache_register(void)
600 {
601         int ret;
602         ret = v9fs_init_inode_cache();
603         if (ret < 0)
604                 return ret;
605 #ifdef CONFIG_9P_FSCACHE
606         return fscache_register_netfs(&v9fs_cache_netfs);
607 #else
608         return ret;
609 #endif
610 }
611
612 static void v9fs_cache_unregister(void)
613 {
614         v9fs_destroy_inode_cache();
615 #ifdef CONFIG_9P_FSCACHE
616         fscache_unregister_netfs(&v9fs_cache_netfs);
617 #endif
618 }
619
620 /**
621  * init_v9fs - Initialize module
622  *
623  */
624
625 static int __init init_v9fs(void)
626 {
627         int err;
628         pr_info("Installing v9fs 9p2000 file system support\n");
629         /* TODO: Setup list of registered trasnport modules */
630
631         err = v9fs_cache_register();
632         if (err < 0) {
633                 pr_err("Failed to register v9fs for caching\n");
634                 return err;
635         }
636
637         err = v9fs_sysfs_init();
638         if (err < 0) {
639                 pr_err("Failed to register with sysfs\n");
640                 goto out_cache;
641         }
642         err = register_filesystem(&v9fs_fs_type);
643         if (err < 0) {
644                 pr_err("Failed to register filesystem\n");
645                 goto out_sysfs_cleanup;
646         }
647
648         return 0;
649
650 out_sysfs_cleanup:
651         v9fs_sysfs_cleanup();
652
653 out_cache:
654         v9fs_cache_unregister();
655
656         return err;
657 }
658
659 /**
660  * exit_v9fs - shutdown module
661  *
662  */
663
664 static void __exit exit_v9fs(void)
665 {
666         v9fs_sysfs_cleanup();
667         v9fs_cache_unregister();
668         unregister_filesystem(&v9fs_fs_type);
669 }
670
671 module_init(init_v9fs)
672 module_exit(exit_v9fs)
673
674 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
675 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
676 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
677 MODULE_LICENSE("GPL");