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