xref: /linux/fs/afs/super.c (revision 22c55fb9eb92395d999b8404d73e58540d11bdd8) 
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 	.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 
67 static struct kmem_cache *afs_inode_cachep;
68 static atomic_t afs_count_active_inodes;
69 
70 enum afs_param {
71 	Opt_autocell,
72 	Opt_dyn,
73 	Opt_flock,
74 	Opt_source,
75 };
76 
77 static 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 
85 static 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  */
96 int __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  */
131 void 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  */
156 static 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  */
190 static 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 	switch (as->flock_mode) {
198 	case afs_flock_mode_unset:	break;
199 	case afs_flock_mode_local:	p = "local";	break;
200 	case afs_flock_mode_openafs:	p = "openafs";	break;
201 	case afs_flock_mode_strict:	p = "strict";	break;
202 	case afs_flock_mode_write:	p = "write";	break;
203 	}
204 	if (p)
205 		seq_printf(m, ",flock=%s", p);
206 
207 	return 0;
208 }
209 
210 /*
211  * Parse the source name to get cell name, volume name, volume type and R/W
212  * selector.
213  *
214  * This can be one of the following:
215  *	"%[cell:]volume[.]"		R/W volume
216  *	"#[cell:]volume[.]"		R/O or R/W volume (R/O parent),
217  *					 or R/W (R/W parent) volume
218  *	"%[cell:]volume.readonly"	R/O volume
219  *	"#[cell:]volume.readonly"	R/O volume
220  *	"%[cell:]volume.backup"		Backup volume
221  *	"#[cell:]volume.backup"		Backup volume
222  */
223 static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
224 {
225 	struct afs_fs_context *ctx = fc->fs_private;
226 	struct afs_cell *cell;
227 	const char *cellname, *suffix, *name = param->string;
228 	int cellnamesz;
229 
230 	_enter(",%s", name);
231 
232 	if (fc->source)
233 		return invalf(fc, "kAFS: Multiple sources not supported");
234 
235 	if (!name) {
236 		printk(KERN_ERR "kAFS: no volume name specified\n");
237 		return -EINVAL;
238 	}
239 
240 	if ((name[0] != '%' && name[0] != '#') || !name[1]) {
241 		/* To use dynroot, we don't want to have to provide a source */
242 		if (strcmp(name, "none") == 0) {
243 			ctx->no_cell = true;
244 			return 0;
245 		}
246 		printk(KERN_ERR "kAFS: unparsable volume name\n");
247 		return -EINVAL;
248 	}
249 
250 	/* determine the type of volume we're looking for */
251 	if (name[0] == '%') {
252 		ctx->type = AFSVL_RWVOL;
253 		ctx->force = true;
254 	}
255 	name++;
256 
257 	/* split the cell name out if there is one */
258 	ctx->volname = strchr(name, ':');
259 	if (ctx->volname) {
260 		cellname = name;
261 		cellnamesz = ctx->volname - name;
262 		ctx->volname++;
263 	} else {
264 		ctx->volname = name;
265 		cellname = NULL;
266 		cellnamesz = 0;
267 	}
268 
269 	/* the volume type is further affected by a possible suffix */
270 	suffix = strrchr(ctx->volname, '.');
271 	if (suffix) {
272 		if (strcmp(suffix, ".readonly") == 0) {
273 			ctx->type = AFSVL_ROVOL;
274 			ctx->force = true;
275 		} else if (strcmp(suffix, ".backup") == 0) {
276 			ctx->type = AFSVL_BACKVOL;
277 			ctx->force = true;
278 		} else if (suffix[1] == 0) {
279 		} else {
280 			suffix = NULL;
281 		}
282 	}
283 
284 	ctx->volnamesz = suffix ?
285 		suffix - ctx->volname : strlen(ctx->volname);
286 
287 	_debug("cell %*.*s [%p]",
288 	       cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
289 
290 	/* lookup the cell record */
291 	if (cellname) {
292 		cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
293 				       NULL, false,
294 				       afs_cell_trace_use_lookup_mount);
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->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  */
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  */
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->volume, afs_volume_trace_put_validate_fc);
384 			ctx->volume = NULL;
385 		}
386 
387 		if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &ctx->cell->flags)) {
388 			ret = afs_cell_detect_alias(ctx->cell, key);
389 			if (ret < 0)
390 				return ret;
391 			if (ret == 1) {
392 				_debug("switch to alias");
393 				key_put(ctx->key);
394 				ctx->key = NULL;
395 				cell = afs_use_cell(ctx->cell->alias_of,
396 						    afs_cell_trace_use_fc_alias);
397 				afs_unuse_cell(ctx->cell, afs_cell_trace_unuse_fc);
398 				ctx->cell = cell;
399 				goto reget_key;
400 			}
401 		}
402 
403 		volume = afs_create_volume(ctx);
404 		if (IS_ERR(volume))
405 			return PTR_ERR(volume);
406 
407 		ctx->volume = volume;
408 		if (volume->type != AFSVL_RWVOL) {
409 			ctx->flock_mode = afs_flock_mode_local;
410 			fc->sb_flags |= SB_RDONLY;
411 		}
412 	}
413 
414 	return 0;
415 }
416 
417 /*
418  * check a superblock to see if it's the one we're looking for
419  */
420 static int afs_test_super(struct super_block *sb, struct fs_context *fc)
421 {
422 	struct afs_fs_context *ctx = fc->fs_private;
423 	struct afs_super_info *as = AFS_FS_S(sb);
424 
425 	return (as->net_ns == fc->net_ns &&
426 		as->volume &&
427 		as->volume->vid == ctx->volume->vid &&
428 		as->cell == ctx->cell &&
429 		!as->dyn_root);
430 }
431 
432 static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
433 {
434 	struct afs_super_info *as = AFS_FS_S(sb);
435 
436 	return (as->net_ns == fc->net_ns &&
437 		as->dyn_root);
438 }
439 
440 static int afs_set_super(struct super_block *sb, struct fs_context *fc)
441 {
442 	return set_anon_super(sb, NULL);
443 }
444 
445 /*
446  * fill in the superblock
447  */
448 static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
449 {
450 	struct afs_super_info *as = AFS_FS_S(sb);
451 	struct inode *inode = NULL;
452 	int ret;
453 
454 	_enter("");
455 
456 	/* fill in the superblock */
457 	sb->s_blocksize		= PAGE_SIZE;
458 	sb->s_blocksize_bits	= PAGE_SHIFT;
459 	sb->s_maxbytes		= MAX_LFS_FILESIZE;
460 	sb->s_magic		= AFS_FS_MAGIC;
461 	sb->s_op		= &afs_super_ops;
462 	if (!as->dyn_root)
463 		sb->s_xattr	= afs_xattr_handlers;
464 	ret = super_setup_bdi(sb);
465 	if (ret)
466 		return ret;
467 
468 	/* allocate the root inode and dentry */
469 	if (as->dyn_root) {
470 		inode = afs_dynroot_iget_root(sb);
471 	} else {
472 		sprintf(sb->s_id, "%llu", as->volume->vid);
473 		afs_activate_volume(as->volume);
474 		inode = afs_root_iget(sb, ctx->key);
475 	}
476 
477 	if (IS_ERR(inode))
478 		return PTR_ERR(inode);
479 
480 	ret = -ENOMEM;
481 	sb->s_root = d_make_root(inode);
482 	if (!sb->s_root)
483 		goto error;
484 
485 	if (as->dyn_root) {
486 		set_default_d_op(sb, &afs_dynroot_dentry_operations);
487 	} else {
488 		set_default_d_op(sb, &afs_fs_dentry_operations);
489 		rcu_assign_pointer(as->volume->sb, sb);
490 	}
491 
492 	_leave(" = 0");
493 	return 0;
494 
495 error:
496 	_leave(" = %d", ret);
497 	return ret;
498 }
499 
500 static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
501 {
502 	struct afs_fs_context *ctx = fc->fs_private;
503 	struct afs_super_info *as;
504 
505 	as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
506 	if (as) {
507 		as->net_ns = get_net(fc->net_ns);
508 		as->flock_mode = ctx->flock_mode;
509 		if (ctx->dyn_root) {
510 			as->dyn_root = true;
511 		} else {
512 			as->cell = afs_use_cell(ctx->cell, afs_cell_trace_use_sbi);
513 			as->volume = afs_get_volume(ctx->volume,
514 						    afs_volume_trace_get_alloc_sbi);
515 		}
516 	}
517 	return as;
518 }
519 
520 static void afs_destroy_sbi(struct afs_super_info *as)
521 {
522 	if (as) {
523 		afs_put_volume(as->volume, afs_volume_trace_put_destroy_sbi);
524 		afs_unuse_cell(as->cell, afs_cell_trace_unuse_sbi);
525 		put_net(as->net_ns);
526 		kfree(as);
527 	}
528 }
529 
530 static void afs_kill_super(struct super_block *sb)
531 {
532 	struct afs_super_info *as = AFS_FS_S(sb);
533 
534 	/* Clear the callback interests (which will do ilookup5) before
535 	 * deactivating the superblock.
536 	 */
537 	if (as->volume)
538 		rcu_assign_pointer(as->volume->sb, NULL);
539 	kill_anon_super(sb);
540 	if (as->volume)
541 		afs_deactivate_volume(as->volume);
542 	afs_destroy_sbi(as);
543 }
544 
545 /*
546  * Get an AFS superblock and root directory.
547  */
548 static int afs_get_tree(struct fs_context *fc)
549 {
550 	struct afs_fs_context *ctx = fc->fs_private;
551 	struct super_block *sb;
552 	struct afs_super_info *as;
553 	int ret;
554 
555 	ret = afs_validate_fc(fc);
556 	if (ret)
557 		goto error;
558 
559 	_enter("");
560 
561 	/* allocate a superblock info record */
562 	ret = -ENOMEM;
563 	as = afs_alloc_sbi(fc);
564 	if (!as)
565 		goto error;
566 	fc->s_fs_info = as;
567 
568 	/* allocate a deviceless superblock */
569 	sb = sget_fc(fc,
570 		     as->dyn_root ? afs_dynroot_test_super : afs_test_super,
571 		     afs_set_super);
572 	if (IS_ERR(sb)) {
573 		ret = PTR_ERR(sb);
574 		goto error;
575 	}
576 
577 	if (!sb->s_root) {
578 		/* initial superblock/root creation */
579 		_debug("create");
580 		ret = afs_fill_super(sb, ctx);
581 		if (ret < 0)
582 			goto error_sb;
583 		sb->s_flags |= SB_ACTIVE;
584 	} else {
585 		_debug("reuse");
586 		ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
587 	}
588 
589 	fc->root = dget(sb->s_root);
590 	trace_afs_get_tree(as->cell, as->volume);
591 	_leave(" = 0 [%p]", sb);
592 	return 0;
593 
594 error_sb:
595 	deactivate_locked_super(sb);
596 error:
597 	_leave(" = %d", ret);
598 	return ret;
599 }
600 
601 static void afs_free_fc(struct fs_context *fc)
602 {
603 	struct afs_fs_context *ctx = fc->fs_private;
604 
605 	afs_destroy_sbi(fc->s_fs_info);
606 	afs_put_volume(ctx->volume, afs_volume_trace_put_free_fc);
607 	afs_unuse_cell(ctx->cell, afs_cell_trace_unuse_fc);
608 	key_put(ctx->key);
609 	kfree(ctx);
610 }
611 
612 static const struct fs_context_operations afs_context_ops = {
613 	.free		= afs_free_fc,
614 	.parse_param	= afs_parse_param,
615 	.get_tree	= afs_get_tree,
616 };
617 
618 /*
619  * Set up the filesystem mount context.
620  */
621 static int afs_init_fs_context(struct fs_context *fc)
622 {
623 	struct afs_fs_context *ctx;
624 	struct afs_cell *cell;
625 
626 	ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
627 	if (!ctx)
628 		return -ENOMEM;
629 
630 	ctx->type = AFSVL_ROVOL;
631 	ctx->net = afs_net(fc->net_ns);
632 
633 	/* Default to the workstation cell. */
634 	cell = afs_find_cell(ctx->net, NULL, 0, afs_cell_trace_use_fc);
635 	if (IS_ERR(cell))
636 		cell = NULL;
637 	ctx->cell = cell;
638 
639 	fc->fs_private = ctx;
640 	fc->ops = &afs_context_ops;
641 	return 0;
642 }
643 
644 /*
645  * Initialise an inode cache slab element prior to any use.  Note that
646  * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
647  * inode to another.
648  */
649 static void afs_i_init_once(void *_vnode)
650 {
651 	struct afs_vnode *vnode = _vnode;
652 
653 	memset(vnode, 0, sizeof(*vnode));
654 	inode_init_once(&vnode->netfs.inode);
655 	INIT_LIST_HEAD(&vnode->io_lock_waiters);
656 	init_rwsem(&vnode->validate_lock);
657 	spin_lock_init(&vnode->wb_lock);
658 	spin_lock_init(&vnode->lock);
659 	INIT_LIST_HEAD(&vnode->wb_keys);
660 	INIT_LIST_HEAD(&vnode->pending_locks);
661 	INIT_LIST_HEAD(&vnode->granted_locks);
662 	INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
663 	INIT_LIST_HEAD(&vnode->cb_mmap_link);
664 	seqlock_init(&vnode->cb_lock);
665 }
666 
667 /*
668  * allocate an AFS inode struct from our slab cache
669  */
670 static struct inode *afs_alloc_inode(struct super_block *sb)
671 {
672 	struct afs_vnode *vnode;
673 
674 	vnode = alloc_inode_sb(sb, afs_inode_cachep, GFP_KERNEL);
675 	if (!vnode)
676 		return NULL;
677 
678 	atomic_inc(&afs_count_active_inodes);
679 
680 	/* Reset anything that shouldn't leak from one inode to the next. */
681 	memset(&vnode->fid, 0, sizeof(vnode->fid));
682 	memset(&vnode->status, 0, sizeof(vnode->status));
683 	afs_vnode_set_cache(vnode, NULL);
684 
685 	vnode->volume		= NULL;
686 	vnode->lock_key		= NULL;
687 	vnode->permit_cache	= NULL;
688 	vnode->directory	= NULL;
689 	vnode->directory_size	= 0;
690 
691 	vnode->flags		= 1 << AFS_VNODE_UNSET;
692 	vnode->lock_state	= AFS_VNODE_LOCK_NONE;
693 
694 	init_rwsem(&vnode->rmdir_lock);
695 	INIT_WORK(&vnode->cb_work, afs_invalidate_mmap_work);
696 
697 	_leave(" = %p", &vnode->netfs.inode);
698 	return &vnode->netfs.inode;
699 }
700 
701 static void afs_free_inode(struct inode *inode)
702 {
703 	kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
704 }
705 
706 /*
707  * destroy an AFS inode struct
708  */
709 static void afs_destroy_inode(struct inode *inode)
710 {
711 	struct afs_vnode *vnode = AFS_FS_I(inode);
712 
713 	_enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
714 
715 	_debug("DESTROY INODE %p", inode);
716 
717 	atomic_dec(&afs_count_active_inodes);
718 }
719 
720 static void afs_get_volume_status_success(struct afs_operation *op)
721 {
722 	struct afs_volume_status *vs = &op->volstatus.vs;
723 	struct kstatfs *buf = op->volstatus.buf;
724 
725 	if (vs->max_quota == 0)
726 		buf->f_blocks = vs->part_max_blocks;
727 	else
728 		buf->f_blocks = vs->max_quota;
729 
730 	if (buf->f_blocks > vs->blocks_in_use)
731 		buf->f_bavail = buf->f_bfree =
732 			buf->f_blocks - vs->blocks_in_use;
733 }
734 
735 static const struct afs_operation_ops afs_get_volume_status_operation = {
736 	.issue_afs_rpc	= afs_fs_get_volume_status,
737 	.issue_yfs_rpc	= yfs_fs_get_volume_status,
738 	.success	= afs_get_volume_status_success,
739 };
740 
741 /*
742  * return information about an AFS volume
743  */
744 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
745 {
746 	struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
747 	struct afs_operation *op;
748 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
749 
750 	buf->f_type	= dentry->d_sb->s_magic;
751 	buf->f_bsize	= AFS_BLOCK_SIZE;
752 	buf->f_namelen	= AFSNAMEMAX - 1;
753 
754 	if (as->dyn_root) {
755 		buf->f_blocks	= 1;
756 		buf->f_bavail	= 0;
757 		buf->f_bfree	= 0;
758 		return 0;
759 	}
760 
761 	op = afs_alloc_operation(NULL, as->volume);
762 	if (IS_ERR(op))
763 		return PTR_ERR(op);
764 
765 	afs_op_set_vnode(op, 0, vnode);
766 	op->nr_files		= 1;
767 	op->volstatus.buf	= buf;
768 	op->ops			= &afs_get_volume_status_operation;
769 	return afs_do_sync_operation(op);
770 }
771