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1/* AFS superblock handling
2 *
3 * Copyright (c) 2002, 2007, 2018 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/fs_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 void afs_kill_super(struct super_block *sb);
34static struct inode *afs_alloc_inode(struct super_block *sb);
35static void afs_destroy_inode(struct inode *inode);
36static void afs_free_inode(struct inode *inode);
37static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
38static int afs_show_devname(struct seq_file *m, struct dentry *root);
39static int afs_show_options(struct seq_file *m, struct dentry *root);
40static int afs_init_fs_context(struct fs_context *fc);
41static const struct fs_parameter_spec afs_fs_parameters[];
42
43struct file_system_type afs_fs_type = {
44 .owner = THIS_MODULE,
45 .name = "afs",
46 .init_fs_context = afs_init_fs_context,
47 .parameters = afs_fs_parameters,
48 .kill_sb = afs_kill_super,
49 .fs_flags = FS_RENAME_DOES_D_MOVE,
50};
51MODULE_ALIAS_FS("afs");
52
53int afs_net_id;
54
55static const struct super_operations afs_super_ops = {
56 .statfs = afs_statfs,
57 .alloc_inode = afs_alloc_inode,
58 .write_inode = netfs_unpin_writeback,
59 .drop_inode = afs_drop_inode,
60 .destroy_inode = afs_destroy_inode,
61 .free_inode = afs_free_inode,
62 .evict_inode = afs_evict_inode,
63 .show_devname = afs_show_devname,
64 .show_options = afs_show_options,
65};
66
67static struct kmem_cache *afs_inode_cachep;
68static atomic_t afs_count_active_inodes;
69
70enum afs_param {
71 Opt_autocell,
72 Opt_dyn,
73 Opt_flock,
74 Opt_source,
75};
76
77static const struct constant_table afs_param_flock[] = {
78 {"local", afs_flock_mode_local },
79 {"openafs", afs_flock_mode_openafs },
80 {"strict", afs_flock_mode_strict },
81 {"write", afs_flock_mode_write },
82 {}
83};
84
85static const struct fs_parameter_spec afs_fs_parameters[] = {
86 fsparam_flag ("autocell", Opt_autocell),
87 fsparam_flag ("dyn", Opt_dyn),
88 fsparam_enum ("flock", Opt_flock, afs_param_flock),
89 fsparam_string("source", Opt_source),
90 {}
91};
92
93/*
94 * initialise the filesystem
95 */
96int __init afs_fs_init(void)
97{
98 int ret;
99
100 _enter("");
101
102 /* create ourselves an inode cache */
103 atomic_set(&afs_count_active_inodes, 0);
104
105 ret = -ENOMEM;
106 afs_inode_cachep = kmem_cache_create("afs_inode_cache",
107 sizeof(struct afs_vnode),
108 0,
109 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
110 afs_i_init_once);
111 if (!afs_inode_cachep) {
112 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
113 return ret;
114 }
115
116 /* now export our filesystem to lesser mortals */
117 ret = register_filesystem(&afs_fs_type);
118 if (ret < 0) {
119 kmem_cache_destroy(afs_inode_cachep);
120 _leave(" = %d", ret);
121 return ret;
122 }
123
124 _leave(" = 0");
125 return 0;
126}
127
128/*
129 * clean up the filesystem
130 */
131void afs_fs_exit(void)
132{
133 _enter("");
134
135 afs_mntpt_kill_timer();
136 unregister_filesystem(&afs_fs_type);
137
138 if (atomic_read(&afs_count_active_inodes) != 0) {
139 printk("kAFS: %d active inode objects still present\n",
140 atomic_read(&afs_count_active_inodes));
141 BUG();
142 }
143
144 /*
145 * Make sure all delayed rcu free inodes are flushed before we
146 * destroy cache.
147 */
148 rcu_barrier();
149 kmem_cache_destroy(afs_inode_cachep);
150 _leave("");
151}
152
153/*
154 * Display the mount device name in /proc/mounts.
155 */
156static int afs_show_devname(struct seq_file *m, struct dentry *root)
157{
158 struct afs_super_info *as = AFS_FS_S(root->d_sb);
159 struct afs_volume *volume = as->volume;
160 struct afs_cell *cell = as->cell;
161 const char *suf = "";
162 char pref = '%';
163
164 if (as->dyn_root) {
165 seq_puts(m, "none");
166 return 0;
167 }
168
169 switch (volume->type) {
170 case AFSVL_RWVOL:
171 break;
172 case AFSVL_ROVOL:
173 pref = '#';
174 if (volume->type_force)
175 suf = ".readonly";
176 break;
177 case AFSVL_BACKVOL:
178 pref = '#';
179 suf = ".backup";
180 break;
181 }
182
183 seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
184 return 0;
185}
186
187/*
188 * Display the mount options in /proc/mounts.
189 */
190static int afs_show_options(struct seq_file *m, struct dentry *root)
191{
192 struct afs_super_info *as = AFS_FS_S(root->d_sb);
193 const char *p = NULL;
194
195 if (as->dyn_root)
196 seq_puts(m, ",dyn");
197 if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
198 seq_puts(m, ",autocell");
199 switch (as->flock_mode) {
200 case afs_flock_mode_unset: break;
201 case afs_flock_mode_local: p = "local"; break;
202 case afs_flock_mode_openafs: p = "openafs"; break;
203 case afs_flock_mode_strict: p = "strict"; break;
204 case afs_flock_mode_write: p = "write"; break;
205 }
206 if (p)
207 seq_printf(m, ",flock=%s", p);
208
209 return 0;
210}
211
212/*
213 * Parse the source name to get cell name, volume name, volume type and R/W
214 * selector.
215 *
216 * This can be one of the following:
217 * "%[cell:]volume[.]" R/W volume
218 * "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
219 * or R/W (R/W parent) volume
220 * "%[cell:]volume.readonly" R/O volume
221 * "#[cell:]volume.readonly" R/O volume
222 * "%[cell:]volume.backup" Backup volume
223 * "#[cell:]volume.backup" Backup volume
224 */
225static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
226{
227 struct afs_fs_context *ctx = fc->fs_private;
228 struct afs_cell *cell;
229 const char *cellname, *suffix, *name = param->string;
230 int cellnamesz;
231
232 _enter(",%s", name);
233
234 if (fc->source)
235 return invalf(fc, "kAFS: Multiple sources not supported");
236
237 if (!name) {
238 printk(KERN_ERR "kAFS: no volume name specified\n");
239 return -EINVAL;
240 }
241
242 if ((name[0] != '%' && name[0] != '#') || !name[1]) {
243 /* To use dynroot, we don't want to have to provide a source */
244 if (strcmp(name, "none") == 0) {
245 ctx->no_cell = true;
246 return 0;
247 }
248 printk(KERN_ERR "kAFS: unparsable volume name\n");
249 return -EINVAL;
250 }
251
252 /* determine the type of volume we're looking for */
253 if (name[0] == '%') {
254 ctx->type = AFSVL_RWVOL;
255 ctx->force = true;
256 }
257 name++;
258
259 /* split the cell name out if there is one */
260 ctx->volname = strchr(name, ':');
261 if (ctx->volname) {
262 cellname = name;
263 cellnamesz = ctx->volname - name;
264 ctx->volname++;
265 } else {
266 ctx->volname = name;
267 cellname = NULL;
268 cellnamesz = 0;
269 }
270
271 /* the volume type is further affected by a possible suffix */
272 suffix = strrchr(ctx->volname, '.');
273 if (suffix) {
274 if (strcmp(suffix, ".readonly") == 0) {
275 ctx->type = AFSVL_ROVOL;
276 ctx->force = true;
277 } else if (strcmp(suffix, ".backup") == 0) {
278 ctx->type = AFSVL_BACKVOL;
279 ctx->force = true;
280 } else if (suffix[1] == 0) {
281 } else {
282 suffix = NULL;
283 }
284 }
285
286 ctx->volnamesz = suffix ?
287 suffix - ctx->volname : strlen(ctx->volname);
288
289 _debug("cell %*.*s [%p]",
290 cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
291
292 /* lookup the cell record */
293 if (cellname) {
294 cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
295 NULL, false);
296 if (IS_ERR(cell)) {
297 pr_err("kAFS: unable to lookup cell '%*.*s'\n",
298 cellnamesz, cellnamesz, cellname ?: "");
299 return PTR_ERR(cell);
300 }
301 afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_parse);
302 afs_see_cell(cell, afs_cell_trace_see_source);
303 ctx->cell = cell;
304 }
305
306 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
307 ctx->cell->name, ctx->cell,
308 ctx->volnamesz, ctx->volnamesz, ctx->volname,
309 suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
310
311 fc->source = param->string;
312 param->string = NULL;
313 return 0;
314}
315
316/*
317 * Parse a single mount parameter.
318 */
319static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
320{
321 struct fs_parse_result result;
322 struct afs_fs_context *ctx = fc->fs_private;
323 int opt;
324
325 opt = fs_parse(fc, afs_fs_parameters, param, &result);
326 if (opt < 0)
327 return opt;
328
329 switch (opt) {
330 case Opt_source:
331 return afs_parse_source(fc, param);
332
333 case Opt_autocell:
334 ctx->autocell = true;
335 break;
336
337 case Opt_dyn:
338 ctx->dyn_root = true;
339 break;
340
341 case Opt_flock:
342 ctx->flock_mode = result.uint_32;
343 break;
344
345 default:
346 return -EINVAL;
347 }
348
349 _leave(" = 0");
350 return 0;
351}
352
353/*
354 * Validate the options, get the cell key and look up the volume.
355 */
356static int afs_validate_fc(struct fs_context *fc)
357{
358 struct afs_fs_context *ctx = fc->fs_private;
359 struct afs_volume *volume;
360 struct afs_cell *cell;
361 struct key *key;
362 int ret;
363
364 if (!ctx->dyn_root) {
365 if (ctx->no_cell) {
366 pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
367 return -EINVAL;
368 }
369
370 if (!ctx->cell) {
371 pr_warn("kAFS: No cell specified\n");
372 return -EDESTADDRREQ;
373 }
374
375 reget_key:
376 /* We try to do the mount securely. */
377 key = afs_request_key(ctx->cell);
378 if (IS_ERR(key))
379 return PTR_ERR(key);
380
381 ctx->key = key;
382
383 if (ctx->volume) {
384 afs_put_volume(ctx->volume, afs_volume_trace_put_validate_fc);
385 ctx->volume = NULL;
386 }
387
388 if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &ctx->cell->flags)) {
389 ret = afs_cell_detect_alias(ctx->cell, key);
390 if (ret < 0)
391 return ret;
392 if (ret == 1) {
393 _debug("switch to alias");
394 key_put(ctx->key);
395 ctx->key = NULL;
396 cell = afs_use_cell(ctx->cell->alias_of,
397 afs_cell_trace_use_fc_alias);
398 afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
399 ctx->cell = cell;
400 goto reget_key;
401 }
402 }
403
404 volume = afs_create_volume(ctx);
405 if (IS_ERR(volume))
406 return PTR_ERR(volume);
407
408 ctx->volume = volume;
409 if (volume->type != AFSVL_RWVOL) {
410 ctx->flock_mode = afs_flock_mode_local;
411 fc->sb_flags |= SB_RDONLY;
412 }
413 }
414
415 return 0;
416}
417
418/*
419 * check a superblock to see if it's the one we're looking for
420 */
421static int afs_test_super(struct super_block *sb, struct fs_context *fc)
422{
423 struct afs_fs_context *ctx = fc->fs_private;
424 struct afs_super_info *as = AFS_FS_S(sb);
425
426 return (as->net_ns == fc->net_ns &&
427 as->volume &&
428 as->volume->vid == ctx->volume->vid &&
429 as->cell == ctx->cell &&
430 !as->dyn_root);
431}
432
433static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
434{
435 struct afs_super_info *as = AFS_FS_S(sb);
436
437 return (as->net_ns == fc->net_ns &&
438 as->dyn_root);
439}
440
441static int afs_set_super(struct super_block *sb, struct fs_context *fc)
442{
443 return set_anon_super(sb, NULL);
444}
445
446/*
447 * fill in the superblock
448 */
449static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
450{
451 struct afs_super_info *as = AFS_FS_S(sb);
452 struct inode *inode = NULL;
453 int ret;
454
455 _enter("");
456
457 /* fill in the superblock */
458 sb->s_blocksize = PAGE_SIZE;
459 sb->s_blocksize_bits = PAGE_SHIFT;
460 sb->s_maxbytes = MAX_LFS_FILESIZE;
461 sb->s_magic = AFS_FS_MAGIC;
462 sb->s_op = &afs_super_ops;
463 if (!as->dyn_root)
464 sb->s_xattr = afs_xattr_handlers;
465 ret = super_setup_bdi(sb);
466 if (ret)
467 return ret;
468
469 /* allocate the root inode and dentry */
470 if (as->dyn_root) {
471 inode = afs_iget_pseudo_dir(sb, true);
472 } else {
473 sprintf(sb->s_id, "%llu", as->volume->vid);
474 afs_activate_volume(as->volume);
475 inode = afs_root_iget(sb, ctx->key);
476 }
477
478 if (IS_ERR(inode))
479 return PTR_ERR(inode);
480
481 if (ctx->autocell || as->dyn_root)
482 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
483
484 ret = -ENOMEM;
485 sb->s_root = d_make_root(inode);
486 if (!sb->s_root)
487 goto error;
488
489 if (as->dyn_root) {
490 sb->s_d_op = &afs_dynroot_dentry_operations;
491 ret = afs_dynroot_populate(sb);
492 if (ret < 0)
493 goto error;
494 } else {
495 sb->s_d_op = &afs_fs_dentry_operations;
496 rcu_assign_pointer(as->volume->sb, sb);
497 }
498
499 _leave(" = 0");
500 return 0;
501
502error:
503 _leave(" = %d", ret);
504 return ret;
505}
506
507static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
508{
509 struct afs_fs_context *ctx = fc->fs_private;
510 struct afs_super_info *as;
511
512 as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
513 if (as) {
514 as->net_ns = get_net(fc->net_ns);
515 as->flock_mode = ctx->flock_mode;
516 if (ctx->dyn_root) {
517 as->dyn_root = true;
518 } else {
519 as->cell = afs_use_cell(ctx->cell, afs_cell_trace_use_sbi);
520 as->volume = afs_get_volume(ctx->volume,
521 afs_volume_trace_get_alloc_sbi);
522 }
523 }
524 return as;
525}
526
527static void afs_destroy_sbi(struct afs_super_info *as)
528{
529 if (as) {
530 struct afs_net *net = afs_net(as->net_ns);
531 afs_put_volume(as->volume, afs_volume_trace_put_destroy_sbi);
532 afs_unuse_cell(net, as->cell, afs_cell_trace_unuse_sbi);
533 put_net(as->net_ns);
534 kfree(as);
535 }
536}
537
538static void afs_kill_super(struct super_block *sb)
539{
540 struct afs_super_info *as = AFS_FS_S(sb);
541
542 if (as->dyn_root)
543 afs_dynroot_depopulate(sb);
544
545 /* Clear the callback interests (which will do ilookup5) before
546 * deactivating the superblock.
547 */
548 if (as->volume)
549 rcu_assign_pointer(as->volume->sb, NULL);
550 kill_anon_super(sb);
551 if (as->volume)
552 afs_deactivate_volume(as->volume);
553 afs_destroy_sbi(as);
554}
555
556/*
557 * Get an AFS superblock and root directory.
558 */
559static int afs_get_tree(struct fs_context *fc)
560{
561 struct afs_fs_context *ctx = fc->fs_private;
562 struct super_block *sb;
563 struct afs_super_info *as;
564 int ret;
565
566 ret = afs_validate_fc(fc);
567 if (ret)
568 goto error;
569
570 _enter("");
571
572 /* allocate a superblock info record */
573 ret = -ENOMEM;
574 as = afs_alloc_sbi(fc);
575 if (!as)
576 goto error;
577 fc->s_fs_info = as;
578
579 /* allocate a deviceless superblock */
580 sb = sget_fc(fc,
581 as->dyn_root ? afs_dynroot_test_super : afs_test_super,
582 afs_set_super);
583 if (IS_ERR(sb)) {
584 ret = PTR_ERR(sb);
585 goto error;
586 }
587
588 if (!sb->s_root) {
589 /* initial superblock/root creation */
590 _debug("create");
591 ret = afs_fill_super(sb, ctx);
592 if (ret < 0)
593 goto error_sb;
594 sb->s_flags |= SB_ACTIVE;
595 } else {
596 _debug("reuse");
597 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
598 }
599
600 fc->root = dget(sb->s_root);
601 trace_afs_get_tree(as->cell, as->volume);
602 _leave(" = 0 [%p]", sb);
603 return 0;
604
605error_sb:
606 deactivate_locked_super(sb);
607error:
608 _leave(" = %d", ret);
609 return ret;
610}
611
612static void afs_free_fc(struct fs_context *fc)
613{
614 struct afs_fs_context *ctx = fc->fs_private;
615
616 afs_destroy_sbi(fc->s_fs_info);
617 afs_put_volume(ctx->volume, afs_volume_trace_put_free_fc);
618 afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
619 key_put(ctx->key);
620 kfree(ctx);
621}
622
623static const struct fs_context_operations afs_context_ops = {
624 .free = afs_free_fc,
625 .parse_param = afs_parse_param,
626 .get_tree = afs_get_tree,
627};
628
629/*
630 * Set up the filesystem mount context.
631 */
632static int afs_init_fs_context(struct fs_context *fc)
633{
634 struct afs_fs_context *ctx;
635 struct afs_cell *cell;
636
637 ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
638 if (!ctx)
639 return -ENOMEM;
640
641 ctx->type = AFSVL_ROVOL;
642 ctx->net = afs_net(fc->net_ns);
643
644 /* Default to the workstation cell. */
645 cell = afs_find_cell(ctx->net, NULL, 0, afs_cell_trace_use_fc);
646 if (IS_ERR(cell))
647 cell = NULL;
648 ctx->cell = cell;
649
650 fc->fs_private = ctx;
651 fc->ops = &afs_context_ops;
652 return 0;
653}
654
655/*
656 * Initialise an inode cache slab element prior to any use. Note that
657 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
658 * inode to another.
659 */
660static void afs_i_init_once(void *_vnode)
661{
662 struct afs_vnode *vnode = _vnode;
663
664 memset(vnode, 0, sizeof(*vnode));
665 inode_init_once(&vnode->netfs.inode);
666 mutex_init(&vnode->io_lock);
667 init_rwsem(&vnode->validate_lock);
668 spin_lock_init(&vnode->wb_lock);
669 spin_lock_init(&vnode->lock);
670 INIT_LIST_HEAD(&vnode->wb_keys);
671 INIT_LIST_HEAD(&vnode->pending_locks);
672 INIT_LIST_HEAD(&vnode->granted_locks);
673 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
674 INIT_LIST_HEAD(&vnode->cb_mmap_link);
675 seqlock_init(&vnode->cb_lock);
676}
677
678/*
679 * allocate an AFS inode struct from our slab cache
680 */
681static struct inode *afs_alloc_inode(struct super_block *sb)
682{
683 struct afs_vnode *vnode;
684
685 vnode = alloc_inode_sb(sb, afs_inode_cachep, GFP_KERNEL);
686 if (!vnode)
687 return NULL;
688
689 atomic_inc(&afs_count_active_inodes);
690
691 /* Reset anything that shouldn't leak from one inode to the next. */
692 memset(&vnode->fid, 0, sizeof(vnode->fid));
693 memset(&vnode->status, 0, sizeof(vnode->status));
694 afs_vnode_set_cache(vnode, NULL);
695
696 vnode->volume = NULL;
697 vnode->lock_key = NULL;
698 vnode->permit_cache = NULL;
699
700 vnode->flags = 1 << AFS_VNODE_UNSET;
701 vnode->lock_state = AFS_VNODE_LOCK_NONE;
702
703 init_rwsem(&vnode->rmdir_lock);
704 INIT_WORK(&vnode->cb_work, afs_invalidate_mmap_work);
705
706 _leave(" = %p", &vnode->netfs.inode);
707 return &vnode->netfs.inode;
708}
709
710static void afs_free_inode(struct inode *inode)
711{
712 kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
713}
714
715/*
716 * destroy an AFS inode struct
717 */
718static void afs_destroy_inode(struct inode *inode)
719{
720 struct afs_vnode *vnode = AFS_FS_I(inode);
721
722 _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
723
724 _debug("DESTROY INODE %p", inode);
725
726 atomic_dec(&afs_count_active_inodes);
727}
728
729static void afs_get_volume_status_success(struct afs_operation *op)
730{
731 struct afs_volume_status *vs = &op->volstatus.vs;
732 struct kstatfs *buf = op->volstatus.buf;
733
734 if (vs->max_quota == 0)
735 buf->f_blocks = vs->part_max_blocks;
736 else
737 buf->f_blocks = vs->max_quota;
738
739 if (buf->f_blocks > vs->blocks_in_use)
740 buf->f_bavail = buf->f_bfree =
741 buf->f_blocks - vs->blocks_in_use;
742}
743
744static const struct afs_operation_ops afs_get_volume_status_operation = {
745 .issue_afs_rpc = afs_fs_get_volume_status,
746 .issue_yfs_rpc = yfs_fs_get_volume_status,
747 .success = afs_get_volume_status_success,
748};
749
750/*
751 * return information about an AFS volume
752 */
753static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
754{
755 struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
756 struct afs_operation *op;
757 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
758
759 buf->f_type = dentry->d_sb->s_magic;
760 buf->f_bsize = AFS_BLOCK_SIZE;
761 buf->f_namelen = AFSNAMEMAX - 1;
762
763 if (as->dyn_root) {
764 buf->f_blocks = 1;
765 buf->f_bavail = 0;
766 buf->f_bfree = 0;
767 return 0;
768 }
769
770 op = afs_alloc_operation(NULL, as->volume);
771 if (IS_ERR(op))
772 return PTR_ERR(op);
773
774 afs_op_set_vnode(op, 0, vnode);
775 op->nr_files = 1;
776 op->volstatus.buf = buf;
777 op->ops = &afs_get_volume_status_operation;
778 return afs_do_sync_operation(op);
779}
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}