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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, Opt_noxattr, Opt_directio, Opt_ignoreqv,
42 /* Access options */
43 Opt_access, Opt_posixacl,
44 /* Lock timeout option */
45 Opt_locktimeout,
46 /* Error token */
47 Opt_err
48};
49
50static const match_table_t tokens = {
51 {Opt_debug, "debug=%x"},
52 {Opt_dfltuid, "dfltuid=%u"},
53 {Opt_dfltgid, "dfltgid=%u"},
54 {Opt_afid, "afid=%u"},
55 {Opt_uname, "uname=%s"},
56 {Opt_remotename, "aname=%s"},
57 {Opt_nodevmap, "nodevmap"},
58 {Opt_noxattr, "noxattr"},
59 {Opt_directio, "directio"},
60 {Opt_ignoreqv, "ignoreqv"},
61 {Opt_cache, "cache=%s"},
62 {Opt_cachetag, "cachetag=%s"},
63 {Opt_access, "access=%s"},
64 {Opt_posixacl, "posixacl"},
65 {Opt_locktimeout, "locktimeout=%u"},
66 {Opt_err, NULL}
67};
68
69/* Interpret mount options for cache mode */
70static int get_cache_mode(char *s)
71{
72 int version = -EINVAL;
73
74 if (!strcmp(s, "loose")) {
75 version = CACHE_SC_LOOSE;
76 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
77 } else if (!strcmp(s, "fscache")) {
78 version = CACHE_SC_FSCACHE;
79 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
80 } else if (!strcmp(s, "mmap")) {
81 version = CACHE_SC_MMAP;
82 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
83 } else if (!strcmp(s, "readahead")) {
84 version = CACHE_SC_READAHEAD;
85 p9_debug(P9_DEBUG_9P, "Cache mode: readahead\n");
86 } else if (!strcmp(s, "none")) {
87 version = CACHE_SC_NONE;
88 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
89 } else if (kstrtoint(s, 0, &version) != 0) {
90 version = -EINVAL;
91 pr_info("Unknown Cache mode or invalid value %s\n", s);
92 }
93 return version;
94}
95
96/*
97 * Display the mount options in /proc/mounts.
98 */
99int v9fs_show_options(struct seq_file *m, struct dentry *root)
100{
101 struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
102
103 if (v9ses->debug)
104 seq_printf(m, ",debug=%x", v9ses->debug);
105 if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
106 seq_printf(m, ",dfltuid=%u",
107 from_kuid_munged(&init_user_ns, v9ses->dfltuid));
108 if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
109 seq_printf(m, ",dfltgid=%u",
110 from_kgid_munged(&init_user_ns, v9ses->dfltgid));
111 if (v9ses->afid != ~0)
112 seq_printf(m, ",afid=%u", v9ses->afid);
113 if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
114 seq_printf(m, ",uname=%s", v9ses->uname);
115 if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
116 seq_printf(m, ",aname=%s", v9ses->aname);
117 if (v9ses->nodev)
118 seq_puts(m, ",nodevmap");
119 if (v9ses->cache)
120 seq_printf(m, ",cache=%x", v9ses->cache);
121#ifdef CONFIG_9P_FSCACHE
122 if (v9ses->cachetag && (v9ses->cache & CACHE_FSCACHE))
123 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
124#endif
125
126 switch (v9ses->flags & V9FS_ACCESS_MASK) {
127 case V9FS_ACCESS_USER:
128 seq_puts(m, ",access=user");
129 break;
130 case V9FS_ACCESS_ANY:
131 seq_puts(m, ",access=any");
132 break;
133 case V9FS_ACCESS_CLIENT:
134 seq_puts(m, ",access=client");
135 break;
136 case V9FS_ACCESS_SINGLE:
137 seq_printf(m, ",access=%u",
138 from_kuid_munged(&init_user_ns, v9ses->uid));
139 break;
140 }
141
142 if (v9ses->flags & V9FS_IGNORE_QV)
143 seq_puts(m, ",ignoreqv");
144 if (v9ses->flags & V9FS_DIRECT_IO)
145 seq_puts(m, ",directio");
146 if (v9ses->flags & V9FS_POSIX_ACL)
147 seq_puts(m, ",posixacl");
148
149 if (v9ses->flags & V9FS_NO_XATTR)
150 seq_puts(m, ",noxattr");
151
152 return p9_show_client_options(m, v9ses->clnt);
153}
154
155/**
156 * v9fs_parse_options - parse mount options into session structure
157 * @v9ses: existing v9fs session information
158 * @opts: The mount option string
159 *
160 * Return 0 upon success, -ERRNO upon failure.
161 */
162
163static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
164{
165 char *options, *tmp_options;
166 substring_t args[MAX_OPT_ARGS];
167 char *p;
168 int option = 0;
169 char *s;
170 int ret = 0;
171
172 /* setup defaults */
173 v9ses->afid = ~0;
174 v9ses->debug = 0;
175 v9ses->cache = CACHE_NONE;
176#ifdef CONFIG_9P_FSCACHE
177 v9ses->cachetag = NULL;
178#endif
179 v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
180
181 if (!opts)
182 return 0;
183
184 tmp_options = kstrdup(opts, GFP_KERNEL);
185 if (!tmp_options) {
186 ret = -ENOMEM;
187 goto fail_option_alloc;
188 }
189 options = tmp_options;
190
191 while ((p = strsep(&options, ",")) != NULL) {
192 int token, r;
193
194 if (!*p)
195 continue;
196
197 token = match_token(p, tokens, args);
198 switch (token) {
199 case Opt_debug:
200 r = match_int(&args[0], &option);
201 if (r < 0) {
202 p9_debug(P9_DEBUG_ERROR,
203 "integer field, but no integer?\n");
204 ret = r;
205 } else {
206 v9ses->debug = option;
207#ifdef CONFIG_NET_9P_DEBUG
208 p9_debug_level = option;
209#endif
210 }
211 break;
212
213 case Opt_dfltuid:
214 r = match_int(&args[0], &option);
215 if (r < 0) {
216 p9_debug(P9_DEBUG_ERROR,
217 "integer field, but no integer?\n");
218 ret = r;
219 continue;
220 }
221 v9ses->dfltuid = make_kuid(current_user_ns(), option);
222 if (!uid_valid(v9ses->dfltuid)) {
223 p9_debug(P9_DEBUG_ERROR,
224 "uid field, but not a uid?\n");
225 ret = -EINVAL;
226 }
227 break;
228 case Opt_dfltgid:
229 r = match_int(&args[0], &option);
230 if (r < 0) {
231 p9_debug(P9_DEBUG_ERROR,
232 "integer field, but no integer?\n");
233 ret = r;
234 continue;
235 }
236 v9ses->dfltgid = make_kgid(current_user_ns(), option);
237 if (!gid_valid(v9ses->dfltgid)) {
238 p9_debug(P9_DEBUG_ERROR,
239 "gid field, but not a gid?\n");
240 ret = -EINVAL;
241 }
242 break;
243 case Opt_afid:
244 r = match_int(&args[0], &option);
245 if (r < 0) {
246 p9_debug(P9_DEBUG_ERROR,
247 "integer field, but no integer?\n");
248 ret = r;
249 } else {
250 v9ses->afid = option;
251 }
252 break;
253 case Opt_uname:
254 kfree(v9ses->uname);
255 v9ses->uname = match_strdup(&args[0]);
256 if (!v9ses->uname) {
257 ret = -ENOMEM;
258 goto free_and_return;
259 }
260 break;
261 case Opt_remotename:
262 kfree(v9ses->aname);
263 v9ses->aname = match_strdup(&args[0]);
264 if (!v9ses->aname) {
265 ret = -ENOMEM;
266 goto free_and_return;
267 }
268 break;
269 case Opt_nodevmap:
270 v9ses->nodev = 1;
271 break;
272 case Opt_noxattr:
273 v9ses->flags |= V9FS_NO_XATTR;
274 break;
275 case Opt_directio:
276 v9ses->flags |= V9FS_DIRECT_IO;
277 break;
278 case Opt_ignoreqv:
279 v9ses->flags |= V9FS_IGNORE_QV;
280 break;
281 case Opt_cachetag:
282#ifdef CONFIG_9P_FSCACHE
283 kfree(v9ses->cachetag);
284 v9ses->cachetag = match_strdup(&args[0]);
285 if (!v9ses->cachetag) {
286 ret = -ENOMEM;
287 goto free_and_return;
288 }
289#endif
290 break;
291 case Opt_cache:
292 s = match_strdup(&args[0]);
293 if (!s) {
294 ret = -ENOMEM;
295 p9_debug(P9_DEBUG_ERROR,
296 "problem allocating copy of cache arg\n");
297 goto free_and_return;
298 }
299 r = get_cache_mode(s);
300 if (r < 0)
301 ret = r;
302 else
303 v9ses->cache = r;
304
305 kfree(s);
306 break;
307
308 case Opt_access:
309 s = match_strdup(&args[0]);
310 if (!s) {
311 ret = -ENOMEM;
312 p9_debug(P9_DEBUG_ERROR,
313 "problem allocating copy of access arg\n");
314 goto free_and_return;
315 }
316
317 v9ses->flags &= ~V9FS_ACCESS_MASK;
318 if (strcmp(s, "user") == 0)
319 v9ses->flags |= V9FS_ACCESS_USER;
320 else if (strcmp(s, "any") == 0)
321 v9ses->flags |= V9FS_ACCESS_ANY;
322 else if (strcmp(s, "client") == 0) {
323 v9ses->flags |= V9FS_ACCESS_CLIENT;
324 } else {
325 uid_t uid;
326
327 v9ses->flags |= V9FS_ACCESS_SINGLE;
328 r = kstrtouint(s, 10, &uid);
329 if (r) {
330 ret = r;
331 pr_info("Unknown access argument %s: %d\n",
332 s, r);
333 kfree(s);
334 continue;
335 }
336 v9ses->uid = make_kuid(current_user_ns(), uid);
337 if (!uid_valid(v9ses->uid)) {
338 ret = -EINVAL;
339 pr_info("Unknown uid %s\n", s);
340 }
341 }
342
343 kfree(s);
344 break;
345
346 case Opt_posixacl:
347#ifdef CONFIG_9P_FS_POSIX_ACL
348 v9ses->flags |= V9FS_POSIX_ACL;
349#else
350 p9_debug(P9_DEBUG_ERROR,
351 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
352#endif
353 break;
354
355 case Opt_locktimeout:
356 r = match_int(&args[0], &option);
357 if (r < 0) {
358 p9_debug(P9_DEBUG_ERROR,
359 "integer field, but no integer?\n");
360 ret = r;
361 continue;
362 }
363 if (option < 1) {
364 p9_debug(P9_DEBUG_ERROR,
365 "locktimeout must be a greater than zero integer.\n");
366 ret = -EINVAL;
367 continue;
368 }
369 v9ses->session_lock_timeout = (long)option * HZ;
370 break;
371
372 default:
373 continue;
374 }
375 }
376
377free_and_return:
378 kfree(tmp_options);
379fail_option_alloc:
380 return ret;
381}
382
383/**
384 * v9fs_session_init - initialize session
385 * @v9ses: session information structure
386 * @dev_name: device being mounted
387 * @data: options
388 *
389 */
390
391struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
392 const char *dev_name, char *data)
393{
394 struct p9_fid *fid;
395 int rc = -ENOMEM;
396
397 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
398 if (!v9ses->uname)
399 goto err_names;
400
401 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
402 if (!v9ses->aname)
403 goto err_names;
404 init_rwsem(&v9ses->rename_sem);
405
406 v9ses->uid = INVALID_UID;
407 v9ses->dfltuid = V9FS_DEFUID;
408 v9ses->dfltgid = V9FS_DEFGID;
409
410 v9ses->clnt = p9_client_create(dev_name, data);
411 if (IS_ERR(v9ses->clnt)) {
412 rc = PTR_ERR(v9ses->clnt);
413 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
414 goto err_names;
415 }
416
417 v9ses->flags = V9FS_ACCESS_USER;
418
419 if (p9_is_proto_dotl(v9ses->clnt)) {
420 v9ses->flags = V9FS_ACCESS_CLIENT;
421 v9ses->flags |= V9FS_PROTO_2000L;
422 } else if (p9_is_proto_dotu(v9ses->clnt)) {
423 v9ses->flags |= V9FS_PROTO_2000U;
424 }
425
426 rc = v9fs_parse_options(v9ses, data);
427 if (rc < 0)
428 goto err_clnt;
429
430 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
431
432 if (!v9fs_proto_dotl(v9ses) &&
433 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
434 /*
435 * We support ACCESS_CLIENT only for dotl.
436 * Fall back to ACCESS_USER
437 */
438 v9ses->flags &= ~V9FS_ACCESS_MASK;
439 v9ses->flags |= V9FS_ACCESS_USER;
440 }
441 /*FIXME !! */
442 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
443 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
444 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
445
446 v9ses->flags &= ~V9FS_ACCESS_MASK;
447 v9ses->flags |= V9FS_ACCESS_ANY;
448 v9ses->uid = INVALID_UID;
449 }
450 if (!v9fs_proto_dotl(v9ses) ||
451 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
452 /*
453 * We support ACL checks on clinet only if the protocol is
454 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
455 */
456 v9ses->flags &= ~V9FS_ACL_MASK;
457 }
458
459 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
460 v9ses->aname);
461 if (IS_ERR(fid)) {
462 rc = PTR_ERR(fid);
463 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
464 goto err_clnt;
465 }
466
467 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
468 fid->uid = v9ses->uid;
469 else
470 fid->uid = INVALID_UID;
471
472#ifdef CONFIG_9P_FSCACHE
473 /* register the session for caching */
474 if (v9ses->cache & CACHE_FSCACHE) {
475 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
476 if (rc < 0)
477 goto err_clnt;
478 }
479#endif
480 spin_lock(&v9fs_sessionlist_lock);
481 list_add(&v9ses->slist, &v9fs_sessionlist);
482 spin_unlock(&v9fs_sessionlist_lock);
483
484 return fid;
485
486err_clnt:
487#ifdef CONFIG_9P_FSCACHE
488 kfree(v9ses->cachetag);
489#endif
490 p9_client_destroy(v9ses->clnt);
491err_names:
492 kfree(v9ses->uname);
493 kfree(v9ses->aname);
494 return ERR_PTR(rc);
495}
496
497/**
498 * v9fs_session_close - shutdown a session
499 * @v9ses: session information structure
500 *
501 */
502
503void v9fs_session_close(struct v9fs_session_info *v9ses)
504{
505 if (v9ses->clnt) {
506 p9_client_destroy(v9ses->clnt);
507 v9ses->clnt = NULL;
508 }
509
510#ifdef CONFIG_9P_FSCACHE
511 fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);
512 kfree(v9ses->cachetag);
513#endif
514 kfree(v9ses->uname);
515 kfree(v9ses->aname);
516
517 spin_lock(&v9fs_sessionlist_lock);
518 list_del(&v9ses->slist);
519 spin_unlock(&v9fs_sessionlist_lock);
520}
521
522/**
523 * v9fs_session_cancel - terminate a session
524 * @v9ses: session to terminate
525 *
526 * mark transport as disconnected and cancel all pending requests.
527 */
528
529void v9fs_session_cancel(struct v9fs_session_info *v9ses)
530{
531 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
532 p9_client_disconnect(v9ses->clnt);
533}
534
535/**
536 * v9fs_session_begin_cancel - Begin terminate of a session
537 * @v9ses: session to terminate
538 *
539 * After this call we don't allow any request other than clunk.
540 */
541
542void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
543{
544 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
545 p9_client_begin_disconnect(v9ses->clnt);
546}
547
548static struct kobject *v9fs_kobj;
549
550#ifdef CONFIG_9P_FSCACHE
551/*
552 * List caches associated with a session
553 */
554static ssize_t caches_show(struct kobject *kobj,
555 struct kobj_attribute *attr,
556 char *buf)
557{
558 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
559 struct v9fs_session_info *v9ses;
560
561 spin_lock(&v9fs_sessionlist_lock);
562 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
563 if (v9ses->cachetag) {
564 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
565 if (n < 0) {
566 count = n;
567 break;
568 }
569
570 count += n;
571 limit -= n;
572 }
573 }
574
575 spin_unlock(&v9fs_sessionlist_lock);
576 return count;
577}
578
579static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
580#endif /* CONFIG_9P_FSCACHE */
581
582static struct attribute *v9fs_attrs[] = {
583#ifdef CONFIG_9P_FSCACHE
584 &v9fs_attr_cache.attr,
585#endif
586 NULL,
587};
588
589static const struct attribute_group v9fs_attr_group = {
590 .attrs = v9fs_attrs,
591};
592
593/**
594 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
595 *
596 */
597
598static int __init v9fs_sysfs_init(void)
599{
600 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
601 if (!v9fs_kobj)
602 return -ENOMEM;
603
604 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
605 kobject_put(v9fs_kobj);
606 return -ENOMEM;
607 }
608
609 return 0;
610}
611
612/**
613 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
614 *
615 */
616
617static void v9fs_sysfs_cleanup(void)
618{
619 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
620 kobject_put(v9fs_kobj);
621}
622
623static void v9fs_inode_init_once(void *foo)
624{
625 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
626
627 memset(&v9inode->qid, 0, sizeof(v9inode->qid));
628 inode_init_once(&v9inode->netfs.inode);
629}
630
631/**
632 * v9fs_init_inode_cache - initialize a cache for 9P
633 * Returns 0 on success.
634 */
635static int v9fs_init_inode_cache(void)
636{
637 v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
638 sizeof(struct v9fs_inode),
639 0, (SLAB_RECLAIM_ACCOUNT|
640 SLAB_ACCOUNT),
641 v9fs_inode_init_once);
642 if (!v9fs_inode_cache)
643 return -ENOMEM;
644
645 return 0;
646}
647
648/**
649 * v9fs_destroy_inode_cache - destroy the cache of 9P inode
650 *
651 */
652static void v9fs_destroy_inode_cache(void)
653{
654 /*
655 * Make sure all delayed rcu free inodes are flushed before we
656 * destroy cache.
657 */
658 rcu_barrier();
659 kmem_cache_destroy(v9fs_inode_cache);
660}
661
662/**
663 * init_v9fs - Initialize module
664 *
665 */
666
667static int __init init_v9fs(void)
668{
669 int err;
670
671 pr_info("Installing v9fs 9p2000 file system support\n");
672 /* TODO: Setup list of registered trasnport modules */
673
674 err = v9fs_init_inode_cache();
675 if (err < 0) {
676 pr_err("Failed to register v9fs for caching\n");
677 return err;
678 }
679
680 err = v9fs_sysfs_init();
681 if (err < 0) {
682 pr_err("Failed to register with sysfs\n");
683 goto out_cache;
684 }
685 err = register_filesystem(&v9fs_fs_type);
686 if (err < 0) {
687 pr_err("Failed to register filesystem\n");
688 goto out_sysfs_cleanup;
689 }
690
691 return 0;
692
693out_sysfs_cleanup:
694 v9fs_sysfs_cleanup();
695
696out_cache:
697 v9fs_destroy_inode_cache();
698
699 return err;
700}
701
702/**
703 * exit_v9fs - shutdown module
704 *
705 */
706
707static void __exit exit_v9fs(void)
708{
709 v9fs_sysfs_cleanup();
710 v9fs_destroy_inode_cache();
711 unregister_filesystem(&v9fs_fs_type);
712}
713
714module_init(init_v9fs)
715module_exit(exit_v9fs)
716
717MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
718MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
719MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
720MODULE_DESCRIPTION("9P Client File System");
721MODULE_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");