4 * This file contains functions assisting in mapping VFS to 9P2000
6 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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.
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.
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
26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28 #include <linux/module.h>
29 #include <linux/errno.h>
31 #include <linux/sched.h>
32 #include <linux/cred.h>
33 #include <linux/parser.h>
34 #include <linux/idr.h>
35 #include <linux/slab.h>
36 #include <linux/seq_file.h>
37 #include <net/9p/9p.h>
38 #include <net/9p/client.h>
39 #include <net/9p/transport.h>
44 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
45 static LIST_HEAD(v9fs_sessionlist);
46 struct kmem_cache *v9fs_inode_cache;
49 * Option Parsing (code inspired by NFS code)
50 * NOTE: each transport will parse its own options
54 /* Options that take integer arguments */
55 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
57 Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
58 /* Options that take no arguments */
61 Opt_cache_loose, Opt_fscache, Opt_mmap,
63 Opt_access, Opt_posixacl,
64 /* Lock timeout option */
70 static const match_table_t tokens = {
71 {Opt_debug, "debug=%x"},
72 {Opt_dfltuid, "dfltuid=%u"},
73 {Opt_dfltgid, "dfltgid=%u"},
74 {Opt_afid, "afid=%u"},
75 {Opt_uname, "uname=%s"},
76 {Opt_remotename, "aname=%s"},
77 {Opt_nodevmap, "nodevmap"},
78 {Opt_cache, "cache=%s"},
79 {Opt_cache_loose, "loose"},
80 {Opt_fscache, "fscache"},
82 {Opt_cachetag, "cachetag=%s"},
83 {Opt_access, "access=%s"},
84 {Opt_posixacl, "posixacl"},
85 {Opt_locktimeout, "locktimeout=%u"},
89 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
90 [CACHE_NONE] = "none",
91 [CACHE_MMAP] = "mmap",
92 [CACHE_LOOSE] = "loose",
93 [CACHE_FSCACHE] = "fscache",
96 /* Interpret mount options for cache mode */
97 static int get_cache_mode(char *s)
99 int version = -EINVAL;
101 if (!strcmp(s, "loose")) {
102 version = CACHE_LOOSE;
103 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
104 } else if (!strcmp(s, "fscache")) {
105 version = CACHE_FSCACHE;
106 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
107 } else if (!strcmp(s, "mmap")) {
108 version = CACHE_MMAP;
109 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
110 } else if (!strcmp(s, "none")) {
111 version = CACHE_NONE;
112 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
114 pr_info("Unknown Cache mode %s\n", s);
119 * Display the mount options in /proc/mounts.
121 int v9fs_show_options(struct seq_file *m, struct dentry *root)
123 struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
126 seq_printf(m, ",debug=%x", v9ses->debug);
127 if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
128 seq_printf(m, ",dfltuid=%u",
129 from_kuid_munged(&init_user_ns, v9ses->dfltuid));
130 if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
131 seq_printf(m, ",dfltgid=%u",
132 from_kgid_munged(&init_user_ns, v9ses->dfltgid));
133 if (v9ses->afid != ~0)
134 seq_printf(m, ",afid=%u", v9ses->afid);
135 if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
136 seq_printf(m, ",uname=%s", v9ses->uname);
137 if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
138 seq_printf(m, ",aname=%s", v9ses->aname);
140 seq_puts(m, ",nodevmap");
142 seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
143 #ifdef CONFIG_9P_FSCACHE
144 if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
145 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
148 switch (v9ses->flags & V9FS_ACCESS_MASK) {
149 case V9FS_ACCESS_USER:
150 seq_puts(m, ",access=user");
152 case V9FS_ACCESS_ANY:
153 seq_puts(m, ",access=any");
155 case V9FS_ACCESS_CLIENT:
156 seq_puts(m, ",access=client");
158 case V9FS_ACCESS_SINGLE:
159 seq_printf(m, ",access=%u",
160 from_kuid_munged(&init_user_ns, v9ses->uid));
164 if (v9ses->flags & V9FS_POSIX_ACL)
165 seq_puts(m, ",posixacl");
167 return p9_show_client_options(m, v9ses->clnt);
171 * v9fs_parse_options - parse mount options into session structure
172 * @v9ses: existing v9fs session information
174 * Return 0 upon success, -ERRNO upon failure.
177 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
179 char *options, *tmp_options;
180 substring_t args[MAX_OPT_ARGS];
189 v9ses->cache = CACHE_NONE;
190 #ifdef CONFIG_9P_FSCACHE
191 v9ses->cachetag = NULL;
193 v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
198 tmp_options = kstrdup(opts, GFP_KERNEL);
201 goto fail_option_alloc;
203 options = tmp_options;
205 while ((p = strsep(&options, ",")) != NULL) {
209 token = match_token(p, tokens, args);
212 r = match_int(&args[0], &option);
214 p9_debug(P9_DEBUG_ERROR,
215 "integer field, but no integer?\n");
218 v9ses->debug = option;
219 #ifdef CONFIG_NET_9P_DEBUG
220 p9_debug_level = option;
226 r = match_int(&args[0], &option);
228 p9_debug(P9_DEBUG_ERROR,
229 "integer field, but no integer?\n");
233 v9ses->dfltuid = make_kuid(current_user_ns(), option);
234 if (!uid_valid(v9ses->dfltuid)) {
235 p9_debug(P9_DEBUG_ERROR,
236 "uid field, but not a uid?\n");
241 r = match_int(&args[0], &option);
243 p9_debug(P9_DEBUG_ERROR,
244 "integer field, but no integer?\n");
248 v9ses->dfltgid = make_kgid(current_user_ns(), option);
249 if (!gid_valid(v9ses->dfltgid)) {
250 p9_debug(P9_DEBUG_ERROR,
251 "gid field, but not a gid?\n");
256 r = match_int(&args[0], &option);
258 p9_debug(P9_DEBUG_ERROR,
259 "integer field, but no integer?\n");
262 v9ses->afid = option;
267 v9ses->uname = match_strdup(&args[0]);
270 goto free_and_return;
275 v9ses->aname = match_strdup(&args[0]);
278 goto free_and_return;
284 case Opt_cache_loose:
285 v9ses->cache = CACHE_LOOSE;
288 v9ses->cache = CACHE_FSCACHE;
291 v9ses->cache = CACHE_MMAP;
294 #ifdef CONFIG_9P_FSCACHE
295 kfree(v9ses->cachetag);
296 v9ses->cachetag = match_strdup(&args[0]);
297 if (!v9ses->cachetag) {
299 goto free_and_return;
304 s = match_strdup(&args[0]);
307 p9_debug(P9_DEBUG_ERROR,
308 "problem allocating copy of cache arg\n");
309 goto free_and_return;
311 r = get_cache_mode(s);
321 s = match_strdup(&args[0]);
324 p9_debug(P9_DEBUG_ERROR,
325 "problem allocating copy of access arg\n");
326 goto free_and_return;
329 v9ses->flags &= ~V9FS_ACCESS_MASK;
330 if (strcmp(s, "user") == 0)
331 v9ses->flags |= V9FS_ACCESS_USER;
332 else if (strcmp(s, "any") == 0)
333 v9ses->flags |= V9FS_ACCESS_ANY;
334 else if (strcmp(s, "client") == 0) {
335 v9ses->flags |= V9FS_ACCESS_CLIENT;
338 v9ses->flags |= V9FS_ACCESS_SINGLE;
339 uid = simple_strtoul(s, &e, 10);
342 pr_info("Unknown access argument %s\n",
347 v9ses->uid = make_kuid(current_user_ns(), uid);
348 if (!uid_valid(v9ses->uid)) {
350 pr_info("Unknown uid %s\n", s);
358 #ifdef CONFIG_9P_FS_POSIX_ACL
359 v9ses->flags |= V9FS_POSIX_ACL;
361 p9_debug(P9_DEBUG_ERROR,
362 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
366 case Opt_locktimeout:
367 r = match_int(&args[0], &option);
369 p9_debug(P9_DEBUG_ERROR,
370 "integer field, but no integer?\n");
375 p9_debug(P9_DEBUG_ERROR,
376 "locktimeout must be a greater than zero integer.\n");
380 v9ses->session_lock_timeout = (long)option * HZ;
395 * v9fs_session_init - initialize session
396 * @v9ses: session information structure
397 * @dev_name: device being mounted
402 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
403 const char *dev_name, char *data)
408 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
412 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
415 init_rwsem(&v9ses->rename_sem);
417 v9ses->uid = INVALID_UID;
418 v9ses->dfltuid = V9FS_DEFUID;
419 v9ses->dfltgid = V9FS_DEFGID;
421 v9ses->clnt = p9_client_create(dev_name, data);
422 if (IS_ERR(v9ses->clnt)) {
423 rc = PTR_ERR(v9ses->clnt);
424 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
428 v9ses->flags = V9FS_ACCESS_USER;
430 if (p9_is_proto_dotl(v9ses->clnt)) {
431 v9ses->flags = V9FS_ACCESS_CLIENT;
432 v9ses->flags |= V9FS_PROTO_2000L;
433 } else if (p9_is_proto_dotu(v9ses->clnt)) {
434 v9ses->flags |= V9FS_PROTO_2000U;
437 rc = v9fs_parse_options(v9ses, data);
441 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
443 if (!v9fs_proto_dotl(v9ses) &&
444 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
446 * We support ACCESS_CLIENT only for dotl.
447 * Fall back to ACCESS_USER
449 v9ses->flags &= ~V9FS_ACCESS_MASK;
450 v9ses->flags |= V9FS_ACCESS_USER;
453 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
454 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
455 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
457 v9ses->flags &= ~V9FS_ACCESS_MASK;
458 v9ses->flags |= V9FS_ACCESS_ANY;
459 v9ses->uid = INVALID_UID;
461 if (!v9fs_proto_dotl(v9ses) ||
462 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
464 * We support ACL checks on clinet only if the protocol is
465 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
467 v9ses->flags &= ~V9FS_ACL_MASK;
470 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
474 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
478 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
479 fid->uid = v9ses->uid;
481 fid->uid = INVALID_UID;
483 #ifdef CONFIG_9P_FSCACHE
484 /* register the session for caching */
485 v9fs_cache_session_get_cookie(v9ses);
487 spin_lock(&v9fs_sessionlist_lock);
488 list_add(&v9ses->slist, &v9fs_sessionlist);
489 spin_unlock(&v9fs_sessionlist_lock);
494 #ifdef CONFIG_9P_FSCACHE
495 kfree(v9ses->cachetag);
497 p9_client_destroy(v9ses->clnt);
505 * v9fs_session_close - shutdown a session
506 * @v9ses: session information structure
510 void v9fs_session_close(struct v9fs_session_info *v9ses)
513 p9_client_destroy(v9ses->clnt);
517 #ifdef CONFIG_9P_FSCACHE
519 v9fs_cache_session_put_cookie(v9ses);
520 kfree(v9ses->cachetag);
525 spin_lock(&v9fs_sessionlist_lock);
526 list_del(&v9ses->slist);
527 spin_unlock(&v9fs_sessionlist_lock);
531 * v9fs_session_cancel - terminate a session
532 * @v9ses: session to terminate
534 * mark transport as disconnected and cancel all pending requests.
537 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
538 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
539 p9_client_disconnect(v9ses->clnt);
543 * v9fs_session_begin_cancel - Begin terminate of a session
544 * @v9ses: session to terminate
546 * After this call we don't allow any request other than clunk.
549 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
551 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
552 p9_client_begin_disconnect(v9ses->clnt);
555 extern int v9fs_error_init(void);
557 static struct kobject *v9fs_kobj;
559 #ifdef CONFIG_9P_FSCACHE
561 * caches_show - list caches associated with a session
563 * Returns the size of buffer written.
566 static ssize_t caches_show(struct kobject *kobj,
567 struct kobj_attribute *attr,
570 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
571 struct v9fs_session_info *v9ses;
573 spin_lock(&v9fs_sessionlist_lock);
574 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
575 if (v9ses->cachetag) {
576 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
587 spin_unlock(&v9fs_sessionlist_lock);
591 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
592 #endif /* CONFIG_9P_FSCACHE */
594 static struct attribute *v9fs_attrs[] = {
595 #ifdef CONFIG_9P_FSCACHE
596 &v9fs_attr_cache.attr,
601 static struct attribute_group v9fs_attr_group = {
606 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
610 static int __init v9fs_sysfs_init(void)
612 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
616 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
617 kobject_put(v9fs_kobj);
625 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
629 static void v9fs_sysfs_cleanup(void)
631 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
632 kobject_put(v9fs_kobj);
635 static void v9fs_inode_init_once(void *foo)
637 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
638 #ifdef CONFIG_9P_FSCACHE
639 v9inode->fscache = NULL;
641 memset(&v9inode->qid, 0, sizeof(v9inode->qid));
642 inode_init_once(&v9inode->vfs_inode);
646 * v9fs_init_inode_cache - initialize a cache for 9P
647 * Returns 0 on success.
649 static int v9fs_init_inode_cache(void)
651 v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
652 sizeof(struct v9fs_inode),
653 0, (SLAB_RECLAIM_ACCOUNT|
654 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
655 v9fs_inode_init_once);
656 if (!v9fs_inode_cache)
663 * v9fs_destroy_inode_cache - destroy the cache of 9P inode
666 static void v9fs_destroy_inode_cache(void)
669 * Make sure all delayed rcu free inodes are flushed before we
673 kmem_cache_destroy(v9fs_inode_cache);
676 static int v9fs_cache_register(void)
679 ret = v9fs_init_inode_cache();
682 #ifdef CONFIG_9P_FSCACHE
683 ret = fscache_register_netfs(&v9fs_cache_netfs);
685 v9fs_destroy_inode_cache();
690 static void v9fs_cache_unregister(void)
692 v9fs_destroy_inode_cache();
693 #ifdef CONFIG_9P_FSCACHE
694 fscache_unregister_netfs(&v9fs_cache_netfs);
699 * init_v9fs - Initialize module
703 static int __init init_v9fs(void)
706 pr_info("Installing v9fs 9p2000 file system support\n");
707 /* TODO: Setup list of registered trasnport modules */
709 err = v9fs_cache_register();
711 pr_err("Failed to register v9fs for caching\n");
715 err = v9fs_sysfs_init();
717 pr_err("Failed to register with sysfs\n");
720 err = register_filesystem(&v9fs_fs_type);
722 pr_err("Failed to register filesystem\n");
723 goto out_sysfs_cleanup;
729 v9fs_sysfs_cleanup();
732 v9fs_cache_unregister();
738 * exit_v9fs - shutdown module
742 static void __exit exit_v9fs(void)
744 v9fs_sysfs_cleanup();
745 v9fs_cache_unregister();
746 unregister_filesystem(&v9fs_fs_type);
749 module_init(init_v9fs)
750 module_exit(exit_v9fs)
752 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
753 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
754 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
755 MODULE_LICENSE("GPL");