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1/* AFS superblock handling
2 *
3 * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
4 *
5 * This software may be freely redistributed under the terms of the
6 * GNU General Public License.
7 *
8 * You should have received a copy of the GNU General Public License
9 * along with this program; if not, write to the Free Software
10 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
11 *
12 * Authors: David Howells <dhowells@redhat.com>
13 * David Woodhouse <dwmw2@infradead.org>
14 *
15 */
16
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/mount.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/parser.h>
25#include <linux/statfs.h>
26#include <linux/sched.h>
27#include <linux/nsproxy.h>
28#include <linux/magic.h>
29#include <net/net_namespace.h>
30#include "internal.h"
31
32static void afs_i_init_once(void *foo);
33static struct dentry *afs_mount(struct file_system_type *fs_type,
34 int flags, const char *dev_name, void *data);
35static void afs_kill_super(struct super_block *sb);
36static struct inode *afs_alloc_inode(struct super_block *sb);
37static void afs_destroy_inode(struct inode *inode);
38static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
39static int afs_show_devname(struct seq_file *m, struct dentry *root);
40static int afs_show_options(struct seq_file *m, struct dentry *root);
41
42struct file_system_type afs_fs_type = {
43 .owner = THIS_MODULE,
44 .name = "afs",
45 .mount = afs_mount,
46 .kill_sb = afs_kill_super,
47 .fs_flags = 0,
48};
49MODULE_ALIAS_FS("afs");
50
51static const struct super_operations afs_super_ops = {
52 .statfs = afs_statfs,
53 .alloc_inode = afs_alloc_inode,
54 .drop_inode = afs_drop_inode,
55 .destroy_inode = afs_destroy_inode,
56 .evict_inode = afs_evict_inode,
57 .show_devname = afs_show_devname,
58 .show_options = afs_show_options,
59};
60
61static struct kmem_cache *afs_inode_cachep;
62static atomic_t afs_count_active_inodes;
63
64enum {
65 afs_no_opt,
66 afs_opt_cell,
67 afs_opt_dyn,
68 afs_opt_rwpath,
69 afs_opt_vol,
70 afs_opt_autocell,
71};
72
73static const match_table_t afs_options_list = {
74 { afs_opt_cell, "cell=%s" },
75 { afs_opt_dyn, "dyn" },
76 { afs_opt_rwpath, "rwpath" },
77 { afs_opt_vol, "vol=%s" },
78 { afs_opt_autocell, "autocell" },
79 { afs_no_opt, NULL },
80};
81
82/*
83 * initialise the filesystem
84 */
85int __init afs_fs_init(void)
86{
87 int ret;
88
89 _enter("");
90
91 /* create ourselves an inode cache */
92 atomic_set(&afs_count_active_inodes, 0);
93
94 ret = -ENOMEM;
95 afs_inode_cachep = kmem_cache_create("afs_inode_cache",
96 sizeof(struct afs_vnode),
97 0,
98 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
99 afs_i_init_once);
100 if (!afs_inode_cachep) {
101 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
102 return ret;
103 }
104
105 /* now export our filesystem to lesser mortals */
106 ret = register_filesystem(&afs_fs_type);
107 if (ret < 0) {
108 kmem_cache_destroy(afs_inode_cachep);
109 _leave(" = %d", ret);
110 return ret;
111 }
112
113 _leave(" = 0");
114 return 0;
115}
116
117/*
118 * clean up the filesystem
119 */
120void __exit afs_fs_exit(void)
121{
122 _enter("");
123
124 afs_mntpt_kill_timer();
125 unregister_filesystem(&afs_fs_type);
126
127 if (atomic_read(&afs_count_active_inodes) != 0) {
128 printk("kAFS: %d active inode objects still present\n",
129 atomic_read(&afs_count_active_inodes));
130 BUG();
131 }
132
133 /*
134 * Make sure all delayed rcu free inodes are flushed before we
135 * destroy cache.
136 */
137 rcu_barrier();
138 kmem_cache_destroy(afs_inode_cachep);
139 _leave("");
140}
141
142/*
143 * Display the mount device name in /proc/mounts.
144 */
145static int afs_show_devname(struct seq_file *m, struct dentry *root)
146{
147 struct afs_super_info *as = AFS_FS_S(root->d_sb);
148 struct afs_volume *volume = as->volume;
149 struct afs_cell *cell = as->cell;
150 const char *suf = "";
151 char pref = '%';
152
153 if (as->dyn_root) {
154 seq_puts(m, "none");
155 return 0;
156 }
157
158 switch (volume->type) {
159 case AFSVL_RWVOL:
160 break;
161 case AFSVL_ROVOL:
162 pref = '#';
163 if (volume->type_force)
164 suf = ".readonly";
165 break;
166 case AFSVL_BACKVOL:
167 pref = '#';
168 suf = ".backup";
169 break;
170 }
171
172 seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
173 return 0;
174}
175
176/*
177 * Display the mount options in /proc/mounts.
178 */
179static int afs_show_options(struct seq_file *m, struct dentry *root)
180{
181 struct afs_super_info *as = AFS_FS_S(root->d_sb);
182
183 if (as->dyn_root)
184 seq_puts(m, ",dyn");
185 if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
186 seq_puts(m, ",autocell");
187 return 0;
188}
189
190/*
191 * parse the mount options
192 * - this function has been shamelessly adapted from the ext3 fs which
193 * shamelessly adapted it from the msdos fs
194 */
195static int afs_parse_options(struct afs_mount_params *params,
196 char *options, const char **devname)
197{
198 struct afs_cell *cell;
199 substring_t args[MAX_OPT_ARGS];
200 char *p;
201 int token;
202
203 _enter("%s", options);
204
205 options[PAGE_SIZE - 1] = 0;
206
207 while ((p = strsep(&options, ","))) {
208 if (!*p)
209 continue;
210
211 token = match_token(p, afs_options_list, args);
212 switch (token) {
213 case afs_opt_cell:
214 rcu_read_lock();
215 cell = afs_lookup_cell_rcu(params->net,
216 args[0].from,
217 args[0].to - args[0].from);
218 rcu_read_unlock();
219 if (IS_ERR(cell))
220 return PTR_ERR(cell);
221 afs_put_cell(params->net, params->cell);
222 params->cell = cell;
223 break;
224
225 case afs_opt_rwpath:
226 params->rwpath = true;
227 break;
228
229 case afs_opt_vol:
230 *devname = args[0].from;
231 break;
232
233 case afs_opt_autocell:
234 params->autocell = true;
235 break;
236
237 case afs_opt_dyn:
238 params->dyn_root = true;
239 break;
240
241 default:
242 printk(KERN_ERR "kAFS:"
243 " Unknown or invalid mount option: '%s'\n", p);
244 return -EINVAL;
245 }
246 }
247
248 _leave(" = 0");
249 return 0;
250}
251
252/*
253 * parse a device name to get cell name, volume name, volume type and R/W
254 * selector
255 * - this can be one of the following:
256 * "%[cell:]volume[.]" R/W volume
257 * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
258 * or R/W (rwpath=1) volume
259 * "%[cell:]volume.readonly" R/O volume
260 * "#[cell:]volume.readonly" R/O volume
261 * "%[cell:]volume.backup" Backup volume
262 * "#[cell:]volume.backup" Backup volume
263 */
264static int afs_parse_device_name(struct afs_mount_params *params,
265 const char *name)
266{
267 struct afs_cell *cell;
268 const char *cellname, *suffix;
269 int cellnamesz;
270
271 _enter(",%s", name);
272
273 if (!name) {
274 printk(KERN_ERR "kAFS: no volume name specified\n");
275 return -EINVAL;
276 }
277
278 if ((name[0] != '%' && name[0] != '#') || !name[1]) {
279 printk(KERN_ERR "kAFS: unparsable volume name\n");
280 return -EINVAL;
281 }
282
283 /* determine the type of volume we're looking for */
284 params->type = AFSVL_ROVOL;
285 params->force = false;
286 if (params->rwpath || name[0] == '%') {
287 params->type = AFSVL_RWVOL;
288 params->force = true;
289 }
290 name++;
291
292 /* split the cell name out if there is one */
293 params->volname = strchr(name, ':');
294 if (params->volname) {
295 cellname = name;
296 cellnamesz = params->volname - name;
297 params->volname++;
298 } else {
299 params->volname = name;
300 cellname = NULL;
301 cellnamesz = 0;
302 }
303
304 /* the volume type is further affected by a possible suffix */
305 suffix = strrchr(params->volname, '.');
306 if (suffix) {
307 if (strcmp(suffix, ".readonly") == 0) {
308 params->type = AFSVL_ROVOL;
309 params->force = true;
310 } else if (strcmp(suffix, ".backup") == 0) {
311 params->type = AFSVL_BACKVOL;
312 params->force = true;
313 } else if (suffix[1] == 0) {
314 } else {
315 suffix = NULL;
316 }
317 }
318
319 params->volnamesz = suffix ?
320 suffix - params->volname : strlen(params->volname);
321
322 _debug("cell %*.*s [%p]",
323 cellnamesz, cellnamesz, cellname ?: "", params->cell);
324
325 /* lookup the cell record */
326 if (cellname || !params->cell) {
327 cell = afs_lookup_cell(params->net, cellname, cellnamesz,
328 NULL, false);
329 if (IS_ERR(cell)) {
330 printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
331 cellnamesz, cellnamesz, cellname ?: "");
332 return PTR_ERR(cell);
333 }
334 afs_put_cell(params->net, params->cell);
335 params->cell = cell;
336 }
337
338 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
339 params->cell->name, params->cell,
340 params->volnamesz, params->volnamesz, params->volname,
341 suffix ?: "-", params->type, params->force ? " FORCE" : "");
342
343 return 0;
344}
345
346/*
347 * check a superblock to see if it's the one we're looking for
348 */
349static int afs_test_super(struct super_block *sb, void *data)
350{
351 struct afs_super_info *as1 = data;
352 struct afs_super_info *as = AFS_FS_S(sb);
353
354 return (as->net == as1->net &&
355 as->volume &&
356 as->volume->vid == as1->volume->vid);
357}
358
359static int afs_dynroot_test_super(struct super_block *sb, void *data)
360{
361 return false;
362}
363
364static int afs_set_super(struct super_block *sb, void *data)
365{
366 struct afs_super_info *as = data;
367
368 sb->s_fs_info = as;
369 return set_anon_super(sb, NULL);
370}
371
372/*
373 * fill in the superblock
374 */
375static int afs_fill_super(struct super_block *sb,
376 struct afs_mount_params *params)
377{
378 struct afs_super_info *as = AFS_FS_S(sb);
379 struct afs_fid fid;
380 struct inode *inode = NULL;
381 int ret;
382
383 _enter("");
384
385 /* fill in the superblock */
386 sb->s_blocksize = PAGE_SIZE;
387 sb->s_blocksize_bits = PAGE_SHIFT;
388 sb->s_magic = AFS_FS_MAGIC;
389 sb->s_op = &afs_super_ops;
390 if (!as->dyn_root)
391 sb->s_xattr = afs_xattr_handlers;
392 ret = super_setup_bdi(sb);
393 if (ret)
394 return ret;
395 sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
396
397 /* allocate the root inode and dentry */
398 if (as->dyn_root) {
399 inode = afs_iget_pseudo_dir(sb, true);
400 sb->s_flags |= SB_RDONLY;
401 } else {
402 sprintf(sb->s_id, "%u", as->volume->vid);
403 afs_activate_volume(as->volume);
404 fid.vid = as->volume->vid;
405 fid.vnode = 1;
406 fid.unique = 1;
407 inode = afs_iget(sb, params->key, &fid, NULL, NULL, NULL);
408 }
409
410 if (IS_ERR(inode))
411 return PTR_ERR(inode);
412
413 if (params->autocell || params->dyn_root)
414 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
415
416 ret = -ENOMEM;
417 sb->s_root = d_make_root(inode);
418 if (!sb->s_root)
419 goto error;
420
421 if (params->dyn_root)
422 sb->s_d_op = &afs_dynroot_dentry_operations;
423 else
424 sb->s_d_op = &afs_fs_dentry_operations;
425
426 _leave(" = 0");
427 return 0;
428
429error:
430 _leave(" = %d", ret);
431 return ret;
432}
433
434static struct afs_super_info *afs_alloc_sbi(struct afs_mount_params *params)
435{
436 struct afs_super_info *as;
437
438 as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
439 if (as) {
440 as->net = afs_get_net(params->net);
441 if (params->dyn_root)
442 as->dyn_root = true;
443 else
444 as->cell = afs_get_cell(params->cell);
445 }
446 return as;
447}
448
449static void afs_destroy_sbi(struct afs_super_info *as)
450{
451 if (as) {
452 afs_put_volume(as->cell, as->volume);
453 afs_put_cell(as->net, as->cell);
454 afs_put_net(as->net);
455 kfree(as);
456 }
457}
458
459/*
460 * get an AFS superblock
461 */
462static struct dentry *afs_mount(struct file_system_type *fs_type,
463 int flags, const char *dev_name, void *options)
464{
465 struct afs_mount_params params;
466 struct super_block *sb;
467 struct afs_volume *candidate;
468 struct key *key;
469 struct afs_super_info *as;
470 int ret;
471
472 _enter(",,%s,%p", dev_name, options);
473
474 memset(¶ms, 0, sizeof(params));
475 params.net = &__afs_net;
476
477 ret = -EINVAL;
478 if (current->nsproxy->net_ns != &init_net)
479 goto error;
480
481 /* parse the options and device name */
482 if (options) {
483 ret = afs_parse_options(¶ms, options, &dev_name);
484 if (ret < 0)
485 goto error;
486 }
487
488 if (!params.dyn_root) {
489 ret = afs_parse_device_name(¶ms, dev_name);
490 if (ret < 0)
491 goto error;
492
493 /* try and do the mount securely */
494 key = afs_request_key(params.cell);
495 if (IS_ERR(key)) {
496 _leave(" = %ld [key]", PTR_ERR(key));
497 ret = PTR_ERR(key);
498 goto error;
499 }
500 params.key = key;
501 }
502
503 /* allocate a superblock info record */
504 ret = -ENOMEM;
505 as = afs_alloc_sbi(¶ms);
506 if (!as)
507 goto error_key;
508
509 if (!params.dyn_root) {
510 /* Assume we're going to need a volume record; at the very
511 * least we can use it to update the volume record if we have
512 * one already. This checks that the volume exists within the
513 * cell.
514 */
515 candidate = afs_create_volume(¶ms);
516 if (IS_ERR(candidate)) {
517 ret = PTR_ERR(candidate);
518 goto error_as;
519 }
520
521 as->volume = candidate;
522 }
523
524 /* allocate a deviceless superblock */
525 sb = sget(fs_type,
526 as->dyn_root ? afs_dynroot_test_super : afs_test_super,
527 afs_set_super, flags, as);
528 if (IS_ERR(sb)) {
529 ret = PTR_ERR(sb);
530 goto error_as;
531 }
532
533 if (!sb->s_root) {
534 /* initial superblock/root creation */
535 _debug("create");
536 ret = afs_fill_super(sb, ¶ms);
537 if (ret < 0)
538 goto error_sb;
539 as = NULL;
540 sb->s_flags |= SB_ACTIVE;
541 } else {
542 _debug("reuse");
543 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
544 afs_destroy_sbi(as);
545 as = NULL;
546 }
547
548 afs_put_cell(params.net, params.cell);
549 key_put(params.key);
550 _leave(" = 0 [%p]", sb);
551 return dget(sb->s_root);
552
553error_sb:
554 deactivate_locked_super(sb);
555 goto error_key;
556error_as:
557 afs_destroy_sbi(as);
558error_key:
559 key_put(params.key);
560error:
561 afs_put_cell(params.net, params.cell);
562 _leave(" = %d", ret);
563 return ERR_PTR(ret);
564}
565
566static void afs_kill_super(struct super_block *sb)
567{
568 struct afs_super_info *as = AFS_FS_S(sb);
569
570 /* Clear the callback interests (which will do ilookup5) before
571 * deactivating the superblock.
572 */
573 if (as->volume)
574 afs_clear_callback_interests(as->net, as->volume->servers);
575 kill_anon_super(sb);
576 if (as->volume)
577 afs_deactivate_volume(as->volume);
578 afs_destroy_sbi(as);
579}
580
581/*
582 * Initialise an inode cache slab element prior to any use. Note that
583 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
584 * inode to another.
585 */
586static void afs_i_init_once(void *_vnode)
587{
588 struct afs_vnode *vnode = _vnode;
589
590 memset(vnode, 0, sizeof(*vnode));
591 inode_init_once(&vnode->vfs_inode);
592 mutex_init(&vnode->io_lock);
593 init_rwsem(&vnode->validate_lock);
594 spin_lock_init(&vnode->wb_lock);
595 spin_lock_init(&vnode->lock);
596 INIT_LIST_HEAD(&vnode->wb_keys);
597 INIT_LIST_HEAD(&vnode->pending_locks);
598 INIT_LIST_HEAD(&vnode->granted_locks);
599 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
600 seqlock_init(&vnode->cb_lock);
601}
602
603/*
604 * allocate an AFS inode struct from our slab cache
605 */
606static struct inode *afs_alloc_inode(struct super_block *sb)
607{
608 struct afs_vnode *vnode;
609
610 vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
611 if (!vnode)
612 return NULL;
613
614 atomic_inc(&afs_count_active_inodes);
615
616 /* Reset anything that shouldn't leak from one inode to the next. */
617 memset(&vnode->fid, 0, sizeof(vnode->fid));
618 memset(&vnode->status, 0, sizeof(vnode->status));
619
620 vnode->volume = NULL;
621 vnode->lock_key = NULL;
622 vnode->permit_cache = NULL;
623 vnode->cb_interest = NULL;
624#ifdef CONFIG_AFS_FSCACHE
625 vnode->cache = NULL;
626#endif
627
628 vnode->flags = 1 << AFS_VNODE_UNSET;
629 vnode->cb_type = 0;
630 vnode->lock_state = AFS_VNODE_LOCK_NONE;
631
632 _leave(" = %p", &vnode->vfs_inode);
633 return &vnode->vfs_inode;
634}
635
636static void afs_i_callback(struct rcu_head *head)
637{
638 struct inode *inode = container_of(head, struct inode, i_rcu);
639 struct afs_vnode *vnode = AFS_FS_I(inode);
640 kmem_cache_free(afs_inode_cachep, vnode);
641}
642
643/*
644 * destroy an AFS inode struct
645 */
646static void afs_destroy_inode(struct inode *inode)
647{
648 struct afs_vnode *vnode = AFS_FS_I(inode);
649
650 _enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
651
652 _debug("DESTROY INODE %p", inode);
653
654 ASSERTCMP(vnode->cb_interest, ==, NULL);
655
656 call_rcu(&inode->i_rcu, afs_i_callback);
657 atomic_dec(&afs_count_active_inodes);
658}
659
660/*
661 * return information about an AFS volume
662 */
663static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
664{
665 struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
666 struct afs_fs_cursor fc;
667 struct afs_volume_status vs;
668 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
669 struct key *key;
670 int ret;
671
672 buf->f_type = dentry->d_sb->s_magic;
673 buf->f_bsize = AFS_BLOCK_SIZE;
674 buf->f_namelen = AFSNAMEMAX - 1;
675
676 if (as->dyn_root) {
677 buf->f_blocks = 1;
678 buf->f_bavail = 0;
679 buf->f_bfree = 0;
680 return 0;
681 }
682
683 key = afs_request_key(vnode->volume->cell);
684 if (IS_ERR(key))
685 return PTR_ERR(key);
686
687 ret = -ERESTARTSYS;
688 if (afs_begin_vnode_operation(&fc, vnode, key)) {
689 fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
690 while (afs_select_fileserver(&fc)) {
691 fc.cb_break = afs_calc_vnode_cb_break(vnode);
692 afs_fs_get_volume_status(&fc, &vs);
693 }
694
695 afs_check_for_remote_deletion(&fc, fc.vnode);
696 afs_vnode_commit_status(&fc, vnode, fc.cb_break);
697 ret = afs_end_vnode_operation(&fc);
698 }
699
700 key_put(key);
701
702 if (ret == 0) {
703 if (vs.max_quota == 0)
704 buf->f_blocks = vs.part_max_blocks;
705 else
706 buf->f_blocks = vs.max_quota;
707 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
708 }
709
710 return ret;
711}
1/* AFS superblock handling
2 *
3 * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
4 *
5 * This software may be freely redistributed under the terms of the
6 * GNU General Public License.
7 *
8 * You should have received a copy of the GNU General Public License
9 * along with this program; if not, write to the Free Software
10 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
11 *
12 * Authors: David Howells <dhowells@redhat.com>
13 * David Woodhouse <dwmw2@infradead.org>
14 *
15 */
16
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/mount.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/parser.h>
25#include <linux/statfs.h>
26#include <linux/sched.h>
27#include <linux/nsproxy.h>
28#include <net/net_namespace.h>
29#include "internal.h"
30
31#define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
32
33static void afs_i_init_once(void *foo);
34static struct dentry *afs_mount(struct file_system_type *fs_type,
35 int flags, const char *dev_name, void *data);
36static void afs_kill_super(struct super_block *sb);
37static struct inode *afs_alloc_inode(struct super_block *sb);
38static void afs_destroy_inode(struct inode *inode);
39static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
40
41struct file_system_type afs_fs_type = {
42 .owner = THIS_MODULE,
43 .name = "afs",
44 .mount = afs_mount,
45 .kill_sb = afs_kill_super,
46 .fs_flags = 0,
47};
48MODULE_ALIAS_FS("afs");
49
50static const struct super_operations afs_super_ops = {
51 .statfs = afs_statfs,
52 .alloc_inode = afs_alloc_inode,
53 .drop_inode = afs_drop_inode,
54 .destroy_inode = afs_destroy_inode,
55 .evict_inode = afs_evict_inode,
56 .show_options = generic_show_options,
57};
58
59static struct kmem_cache *afs_inode_cachep;
60static atomic_t afs_count_active_inodes;
61
62enum {
63 afs_no_opt,
64 afs_opt_cell,
65 afs_opt_rwpath,
66 afs_opt_vol,
67 afs_opt_autocell,
68};
69
70static const match_table_t afs_options_list = {
71 { afs_opt_cell, "cell=%s" },
72 { afs_opt_rwpath, "rwpath" },
73 { afs_opt_vol, "vol=%s" },
74 { afs_opt_autocell, "autocell" },
75 { afs_no_opt, NULL },
76};
77
78/*
79 * initialise the filesystem
80 */
81int __init afs_fs_init(void)
82{
83 int ret;
84
85 _enter("");
86
87 /* create ourselves an inode cache */
88 atomic_set(&afs_count_active_inodes, 0);
89
90 ret = -ENOMEM;
91 afs_inode_cachep = kmem_cache_create("afs_inode_cache",
92 sizeof(struct afs_vnode),
93 0,
94 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
95 afs_i_init_once);
96 if (!afs_inode_cachep) {
97 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
98 return ret;
99 }
100
101 /* now export our filesystem to lesser mortals */
102 ret = register_filesystem(&afs_fs_type);
103 if (ret < 0) {
104 kmem_cache_destroy(afs_inode_cachep);
105 _leave(" = %d", ret);
106 return ret;
107 }
108
109 _leave(" = 0");
110 return 0;
111}
112
113/*
114 * clean up the filesystem
115 */
116void __exit afs_fs_exit(void)
117{
118 _enter("");
119
120 afs_mntpt_kill_timer();
121 unregister_filesystem(&afs_fs_type);
122
123 if (atomic_read(&afs_count_active_inodes) != 0) {
124 printk("kAFS: %d active inode objects still present\n",
125 atomic_read(&afs_count_active_inodes));
126 BUG();
127 }
128
129 /*
130 * Make sure all delayed rcu free inodes are flushed before we
131 * destroy cache.
132 */
133 rcu_barrier();
134 kmem_cache_destroy(afs_inode_cachep);
135 _leave("");
136}
137
138/*
139 * parse the mount options
140 * - this function has been shamelessly adapted from the ext3 fs which
141 * shamelessly adapted it from the msdos fs
142 */
143static int afs_parse_options(struct afs_mount_params *params,
144 char *options, const char **devname)
145{
146 struct afs_cell *cell;
147 substring_t args[MAX_OPT_ARGS];
148 char *p;
149 int token;
150
151 _enter("%s", options);
152
153 options[PAGE_SIZE - 1] = 0;
154
155 while ((p = strsep(&options, ","))) {
156 if (!*p)
157 continue;
158
159 token = match_token(p, afs_options_list, args);
160 switch (token) {
161 case afs_opt_cell:
162 cell = afs_cell_lookup(args[0].from,
163 args[0].to - args[0].from,
164 false);
165 if (IS_ERR(cell))
166 return PTR_ERR(cell);
167 afs_put_cell(params->cell);
168 params->cell = cell;
169 break;
170
171 case afs_opt_rwpath:
172 params->rwpath = 1;
173 break;
174
175 case afs_opt_vol:
176 *devname = args[0].from;
177 break;
178
179 case afs_opt_autocell:
180 params->autocell = 1;
181 break;
182
183 default:
184 printk(KERN_ERR "kAFS:"
185 " Unknown or invalid mount option: '%s'\n", p);
186 return -EINVAL;
187 }
188 }
189
190 _leave(" = 0");
191 return 0;
192}
193
194/*
195 * parse a device name to get cell name, volume name, volume type and R/W
196 * selector
197 * - this can be one of the following:
198 * "%[cell:]volume[.]" R/W volume
199 * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
200 * or R/W (rwpath=1) volume
201 * "%[cell:]volume.readonly" R/O volume
202 * "#[cell:]volume.readonly" R/O volume
203 * "%[cell:]volume.backup" Backup volume
204 * "#[cell:]volume.backup" Backup volume
205 */
206static int afs_parse_device_name(struct afs_mount_params *params,
207 const char *name)
208{
209 struct afs_cell *cell;
210 const char *cellname, *suffix;
211 int cellnamesz;
212
213 _enter(",%s", name);
214
215 if (!name) {
216 printk(KERN_ERR "kAFS: no volume name specified\n");
217 return -EINVAL;
218 }
219
220 if ((name[0] != '%' && name[0] != '#') || !name[1]) {
221 printk(KERN_ERR "kAFS: unparsable volume name\n");
222 return -EINVAL;
223 }
224
225 /* determine the type of volume we're looking for */
226 params->type = AFSVL_ROVOL;
227 params->force = false;
228 if (params->rwpath || name[0] == '%') {
229 params->type = AFSVL_RWVOL;
230 params->force = true;
231 }
232 name++;
233
234 /* split the cell name out if there is one */
235 params->volname = strchr(name, ':');
236 if (params->volname) {
237 cellname = name;
238 cellnamesz = params->volname - name;
239 params->volname++;
240 } else {
241 params->volname = name;
242 cellname = NULL;
243 cellnamesz = 0;
244 }
245
246 /* the volume type is further affected by a possible suffix */
247 suffix = strrchr(params->volname, '.');
248 if (suffix) {
249 if (strcmp(suffix, ".readonly") == 0) {
250 params->type = AFSVL_ROVOL;
251 params->force = true;
252 } else if (strcmp(suffix, ".backup") == 0) {
253 params->type = AFSVL_BACKVOL;
254 params->force = true;
255 } else if (suffix[1] == 0) {
256 } else {
257 suffix = NULL;
258 }
259 }
260
261 params->volnamesz = suffix ?
262 suffix - params->volname : strlen(params->volname);
263
264 _debug("cell %*.*s [%p]",
265 cellnamesz, cellnamesz, cellname ?: "", params->cell);
266
267 /* lookup the cell record */
268 if (cellname || !params->cell) {
269 cell = afs_cell_lookup(cellname, cellnamesz, true);
270 if (IS_ERR(cell)) {
271 printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
272 cellnamesz, cellnamesz, cellname ?: "");
273 return PTR_ERR(cell);
274 }
275 afs_put_cell(params->cell);
276 params->cell = cell;
277 }
278
279 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
280 params->cell->name, params->cell,
281 params->volnamesz, params->volnamesz, params->volname,
282 suffix ?: "-", params->type, params->force ? " FORCE" : "");
283
284 return 0;
285}
286
287/*
288 * check a superblock to see if it's the one we're looking for
289 */
290static int afs_test_super(struct super_block *sb, void *data)
291{
292 struct afs_super_info *as1 = data;
293 struct afs_super_info *as = sb->s_fs_info;
294
295 return as->volume == as1->volume;
296}
297
298static int afs_set_super(struct super_block *sb, void *data)
299{
300 sb->s_fs_info = data;
301 return set_anon_super(sb, NULL);
302}
303
304/*
305 * fill in the superblock
306 */
307static int afs_fill_super(struct super_block *sb,
308 struct afs_mount_params *params)
309{
310 struct afs_super_info *as = sb->s_fs_info;
311 struct afs_fid fid;
312 struct inode *inode = NULL;
313 int ret;
314
315 _enter("");
316
317 /* fill in the superblock */
318 sb->s_blocksize = PAGE_SIZE;
319 sb->s_blocksize_bits = PAGE_SHIFT;
320 sb->s_magic = AFS_FS_MAGIC;
321 sb->s_op = &afs_super_ops;
322 sb->s_bdi = &as->volume->bdi;
323 strlcpy(sb->s_id, as->volume->vlocation->vldb.name, sizeof(sb->s_id));
324
325 /* allocate the root inode and dentry */
326 fid.vid = as->volume->vid;
327 fid.vnode = 1;
328 fid.unique = 1;
329 inode = afs_iget(sb, params->key, &fid, NULL, NULL);
330 if (IS_ERR(inode))
331 return PTR_ERR(inode);
332
333 if (params->autocell)
334 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
335
336 ret = -ENOMEM;
337 sb->s_root = d_make_root(inode);
338 if (!sb->s_root)
339 goto error;
340
341 sb->s_d_op = &afs_fs_dentry_operations;
342
343 _leave(" = 0");
344 return 0;
345
346error:
347 _leave(" = %d", ret);
348 return ret;
349}
350
351/*
352 * get an AFS superblock
353 */
354static struct dentry *afs_mount(struct file_system_type *fs_type,
355 int flags, const char *dev_name, void *options)
356{
357 struct afs_mount_params params;
358 struct super_block *sb;
359 struct afs_volume *vol;
360 struct key *key;
361 char *new_opts = kstrdup(options, GFP_KERNEL);
362 struct afs_super_info *as;
363 int ret;
364
365 _enter(",,%s,%p", dev_name, options);
366
367 memset(¶ms, 0, sizeof(params));
368
369 ret = -EINVAL;
370 if (current->nsproxy->net_ns != &init_net)
371 goto error;
372
373 /* parse the options and device name */
374 if (options) {
375 ret = afs_parse_options(¶ms, options, &dev_name);
376 if (ret < 0)
377 goto error;
378 }
379
380 ret = afs_parse_device_name(¶ms, dev_name);
381 if (ret < 0)
382 goto error;
383
384 /* try and do the mount securely */
385 key = afs_request_key(params.cell);
386 if (IS_ERR(key)) {
387 _leave(" = %ld [key]", PTR_ERR(key));
388 ret = PTR_ERR(key);
389 goto error;
390 }
391 params.key = key;
392
393 /* parse the device name */
394 vol = afs_volume_lookup(¶ms);
395 if (IS_ERR(vol)) {
396 ret = PTR_ERR(vol);
397 goto error;
398 }
399
400 /* allocate a superblock info record */
401 as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
402 if (!as) {
403 ret = -ENOMEM;
404 afs_put_volume(vol);
405 goto error;
406 }
407 as->volume = vol;
408
409 /* allocate a deviceless superblock */
410 sb = sget(fs_type, afs_test_super, afs_set_super, flags, as);
411 if (IS_ERR(sb)) {
412 ret = PTR_ERR(sb);
413 afs_put_volume(vol);
414 kfree(as);
415 goto error;
416 }
417
418 if (!sb->s_root) {
419 /* initial superblock/root creation */
420 _debug("create");
421 ret = afs_fill_super(sb, ¶ms);
422 if (ret < 0) {
423 deactivate_locked_super(sb);
424 goto error;
425 }
426 save_mount_options(sb, new_opts);
427 sb->s_flags |= MS_ACTIVE;
428 } else {
429 _debug("reuse");
430 ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
431 afs_put_volume(vol);
432 kfree(as);
433 }
434
435 afs_put_cell(params.cell);
436 kfree(new_opts);
437 _leave(" = 0 [%p]", sb);
438 return dget(sb->s_root);
439
440error:
441 afs_put_cell(params.cell);
442 key_put(params.key);
443 kfree(new_opts);
444 _leave(" = %d", ret);
445 return ERR_PTR(ret);
446}
447
448static void afs_kill_super(struct super_block *sb)
449{
450 struct afs_super_info *as = sb->s_fs_info;
451 kill_anon_super(sb);
452 afs_put_volume(as->volume);
453 kfree(as);
454}
455
456/*
457 * initialise an inode cache slab element prior to any use
458 */
459static void afs_i_init_once(void *_vnode)
460{
461 struct afs_vnode *vnode = _vnode;
462
463 memset(vnode, 0, sizeof(*vnode));
464 inode_init_once(&vnode->vfs_inode);
465 init_waitqueue_head(&vnode->update_waitq);
466 mutex_init(&vnode->permits_lock);
467 mutex_init(&vnode->validate_lock);
468 spin_lock_init(&vnode->writeback_lock);
469 spin_lock_init(&vnode->lock);
470 INIT_LIST_HEAD(&vnode->writebacks);
471 INIT_LIST_HEAD(&vnode->pending_locks);
472 INIT_LIST_HEAD(&vnode->granted_locks);
473 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
474 INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
475}
476
477/*
478 * allocate an AFS inode struct from our slab cache
479 */
480static struct inode *afs_alloc_inode(struct super_block *sb)
481{
482 struct afs_vnode *vnode;
483
484 vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
485 if (!vnode)
486 return NULL;
487
488 atomic_inc(&afs_count_active_inodes);
489
490 memset(&vnode->fid, 0, sizeof(vnode->fid));
491 memset(&vnode->status, 0, sizeof(vnode->status));
492
493 vnode->volume = NULL;
494 vnode->update_cnt = 0;
495 vnode->flags = 1 << AFS_VNODE_UNSET;
496 vnode->cb_promised = false;
497
498 _leave(" = %p", &vnode->vfs_inode);
499 return &vnode->vfs_inode;
500}
501
502static void afs_i_callback(struct rcu_head *head)
503{
504 struct inode *inode = container_of(head, struct inode, i_rcu);
505 struct afs_vnode *vnode = AFS_FS_I(inode);
506 kmem_cache_free(afs_inode_cachep, vnode);
507}
508
509/*
510 * destroy an AFS inode struct
511 */
512static void afs_destroy_inode(struct inode *inode)
513{
514 struct afs_vnode *vnode = AFS_FS_I(inode);
515
516 _enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
517
518 _debug("DESTROY INODE %p", inode);
519
520 ASSERTCMP(vnode->server, ==, NULL);
521
522 call_rcu(&inode->i_rcu, afs_i_callback);
523 atomic_dec(&afs_count_active_inodes);
524}
525
526/*
527 * return information about an AFS volume
528 */
529static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
530{
531 struct afs_volume_status vs;
532 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
533 struct key *key;
534 int ret;
535
536 key = afs_request_key(vnode->volume->cell);
537 if (IS_ERR(key))
538 return PTR_ERR(key);
539
540 ret = afs_vnode_get_volume_status(vnode, key, &vs);
541 key_put(key);
542 if (ret < 0) {
543 _leave(" = %d", ret);
544 return ret;
545 }
546
547 buf->f_type = dentry->d_sb->s_magic;
548 buf->f_bsize = AFS_BLOCK_SIZE;
549 buf->f_namelen = AFSNAMEMAX - 1;
550
551 if (vs.max_quota == 0)
552 buf->f_blocks = vs.part_max_blocks;
553 else
554 buf->f_blocks = vs.max_quota;
555 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
556 return 0;
557}