fs/afs/super.c

   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  */
  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  */
 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  */
 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  */
 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  */
 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 (!name) {
 234                 printk(KERN_ERR "kAFS: no volume name specified\n");
 235                 return -EINVAL;
 236         }
 237
 238         if ((name[0] != '%' && name[0] != '#') || !name[1]) {
 239                 /* To use dynroot, we don't want to have to provide a source */
 240                 if (strcmp(name, "none") == 0) {
 241                         ctx->no_cell = true;
 242                         return 0;
 243                 }
 244                 printk(KERN_ERR "kAFS: unparsable volume name\n");
 245                 return -EINVAL;
 246         }
 247
 248         /* determine the type of volume we're looking for */
 249         if (name[0] == '%') {
 250                 ctx->type = AFSVL_RWVOL;
 251                 ctx->force = true;
 252         }
 253         name++;
 254
 255         /* split the cell name out if there is one */
 256         ctx->volname = strchr(name, ':');
 257         if (ctx->volname) {
 258                 cellname = name;
 259                 cellnamesz = ctx->volname - name;
 260                 ctx->volname++;
 261         } else {
 262                 ctx->volname = name;
 263                 cellname = NULL;
 264                 cellnamesz = 0;
 265         }
 266
 267         /* the volume type is further affected by a possible suffix */
 268         suffix = strrchr(ctx->volname, '.');
 269         if (suffix) {
 270                 if (strcmp(suffix, ".readonly") == 0) {
 271                         ctx->type = AFSVL_ROVOL;
 272                         ctx->force = true;
 273                 } else if (strcmp(suffix, ".backup") == 0) {
 274                         ctx->type = AFSVL_BACKVOL;
 275                         ctx->force = true;
 276                 } else if (suffix[1] == 0) {
 277                 } else {
 278                         suffix = NULL;
 279                 }
 280         }
 281
 282         ctx->volnamesz = suffix ?
 283                 suffix - ctx->volname : strlen(ctx->volname);
 284
 285         _debug("cell %*.*s [%p]",
 286                cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
 287
 288         /* lookup the cell record */
 289         if (cellname) {
 290                 cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
 291                                        NULL, false);
 292                 if (IS_ERR(cell)) {
 293                         pr_err("kAFS: unable to lookup cell '%*.*s'\n",
 294                                cellnamesz, cellnamesz, cellname ?: "");
 295                         return PTR_ERR(cell);
 296                 }
 297                 afs_put_cell(ctx->net, ctx->cell);
 298                 ctx->cell = cell;
 299         }
 300
 301         _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
 302                ctx->cell->name, ctx->cell,
 303                ctx->volnamesz, ctx->volnamesz, ctx->volname,
 304                suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
 305
 306         fc->source = param->string;
 307         param->string = NULL;
 308         return 0;
 309 }
 310
 311 /*
 312  * Parse a single mount parameter.
 313  */
 314 static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 315 {
 316         struct fs_parse_result result;
 317         struct afs_fs_context *ctx = fc->fs_private;
 318         int opt;
 319
 320         opt = fs_parse(fc, afs_fs_parameters, param, &result);
 321         if (opt < 0)
 322                 return opt;
 323
 324         switch (opt) {
 325         case Opt_source:
 326                 return afs_parse_source(fc, param);
 327
 328         case Opt_autocell:
 329                 ctx->autocell = true;
 330                 break;
 331
 332         case Opt_dyn:
 333                 ctx->dyn_root = true;
 334                 break;
 335
 336         case Opt_flock:
 337                 ctx->flock_mode = result.uint_32;
 338                 break;
 339
 340         default:
 341                 return -EINVAL;
 342         }
 343
 344         _leave(" = 0");
 345         return 0;
 346 }
 347
 348 /*
 349  * Validate the options, get the cell key and look up the volume.
 350  */
 351 static int afs_validate_fc(struct fs_context *fc)
 352 {
 353         struct afs_fs_context *ctx = fc->fs_private;
 354         struct afs_volume *volume;
 355         struct key *key;
 356
 357         if (!ctx->dyn_root) {
 358                 if (ctx->no_cell) {
 359                         pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
 360                         return -EINVAL;
 361                 }
 362
 363                 if (!ctx->cell) {
 364                         pr_warn("kAFS: No cell specified\n");
 365                         return -EDESTADDRREQ;
 366                 }
 367
 368                 /* We try to do the mount securely. */
 369                 key = afs_request_key(ctx->cell);
 370                 if (IS_ERR(key))
 371                         return PTR_ERR(key);
 372
 373                 ctx->key = key;
 374
 375                 if (ctx->volume) {
 376                         afs_put_volume(ctx->cell, ctx->volume);
 377                         ctx->volume = NULL;
 378                 }
 379
 380                 volume = afs_create_volume(ctx);
 381                 if (IS_ERR(volume))
 382                         return PTR_ERR(volume);
 383
 384                 ctx->volume = volume;
 385         }
 386
 387         return 0;
 388 }
 389
 390 /*
 391  * check a superblock to see if it's the one we're looking for
 392  */
 393 static int afs_test_super(struct super_block *sb, struct fs_context *fc)
 394 {
 395         struct afs_fs_context *ctx = fc->fs_private;
 396         struct afs_super_info *as = AFS_FS_S(sb);
 397
 398         return (as->net_ns == fc->net_ns &&
 399                 as->volume &&
 400                 as->volume->vid == ctx->volume->vid &&
 401                 as->cell == ctx->cell &&
 402                 !as->dyn_root);
 403 }
 404
 405 static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
 406 {
 407         struct afs_super_info *as = AFS_FS_S(sb);
 408
 409         return (as->net_ns == fc->net_ns &&
 410                 as->dyn_root);
 411 }
 412
 413 static int afs_set_super(struct super_block *sb, struct fs_context *fc)
 414 {
 415         return set_anon_super(sb, NULL);
 416 }
 417
 418 /*
 419  * fill in the superblock
 420  */
 421 static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 422 {
 423         struct afs_super_info *as = AFS_FS_S(sb);
 424         struct afs_iget_data iget_data;
 425         struct inode *inode = NULL;
 426         int ret;
 427
 428         _enter("");
 429
 430         /* fill in the superblock */
 431         sb->s_blocksize         = PAGE_SIZE;
 432         sb->s_blocksize_bits    = PAGE_SHIFT;
 433         sb->s_maxbytes          = MAX_LFS_FILESIZE;
 434         sb->s_magic             = AFS_FS_MAGIC;
 435         sb->s_op                = &afs_super_ops;
 436         if (!as->dyn_root)
 437                 sb->s_xattr     = afs_xattr_handlers;
 438         ret = super_setup_bdi(sb);
 439         if (ret)
 440                 return ret;
 441         sb->s_bdi->ra_pages     = VM_READAHEAD_PAGES;
 442
 443         /* allocate the root inode and dentry */
 444         if (as->dyn_root) {
 445                 inode = afs_iget_pseudo_dir(sb, true);
 446         } else {
 447                 sprintf(sb->s_id, "%llu", as->volume->vid);
 448                 afs_activate_volume(as->volume);
 449                 iget_data.fid.vid       = as->volume->vid;
 450                 iget_data.fid.vnode     = 1;
 451                 iget_data.fid.vnode_hi  = 0;
 452                 iget_data.fid.unique    = 1;
 453                 iget_data.cb_v_break    = as->volume->cb_v_break;
 454                 iget_data.cb_s_break    = 0;
 455                 inode = afs_iget(sb, ctx->key, &iget_data, NULL, NULL, NULL);
 456         }
 457
 458         if (IS_ERR(inode))
 459                 return PTR_ERR(inode);
 460
 461         if (ctx->autocell || as->dyn_root)
 462                 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
 463
 464         ret = -ENOMEM;
 465         sb->s_root = d_make_root(inode);
 466         if (!sb->s_root)
 467                 goto error;
 468
 469         if (as->dyn_root) {
 470                 sb->s_d_op = &afs_dynroot_dentry_operations;
 471                 ret = afs_dynroot_populate(sb);
 472                 if (ret < 0)
 473                         goto error;
 474         } else {
 475                 sb->s_d_op = &afs_fs_dentry_operations;
 476         }
 477
 478         _leave(" = 0");
 479         return 0;
 480
 481 error:
 482         _leave(" = %d", ret);
 483         return ret;
 484 }
 485
 486 static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
 487 {
 488         struct afs_fs_context *ctx = fc->fs_private;
 489         struct afs_super_info *as;
 490
 491         as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
 492         if (as) {
 493                 as->net_ns = get_net(fc->net_ns);
 494                 as->flock_mode = ctx->flock_mode;
 495                 if (ctx->dyn_root) {
 496                         as->dyn_root = true;
 497                 } else {
 498                         as->cell = afs_get_cell(ctx->cell);
 499                         as->volume = __afs_get_volume(ctx->volume);
 500                 }
 501         }
 502         return as;
 503 }
 504
 505 static void afs_destroy_sbi(struct afs_super_info *as)
 506 {
 507         if (as) {
 508                 afs_put_volume(as->cell, as->volume);
 509                 afs_put_cell(afs_net(as->net_ns), as->cell);
 510                 put_net(as->net_ns);
 511                 kfree(as);
 512         }
 513 }
 514
 515 static void afs_kill_super(struct super_block *sb)
 516 {
 517         struct afs_super_info *as = AFS_FS_S(sb);
 518         struct afs_net *net = afs_net(as->net_ns);
 519
 520         if (as->dyn_root)
 521                 afs_dynroot_depopulate(sb);
 522
 523         /* Clear the callback interests (which will do ilookup5) before
 524          * deactivating the superblock.
 525          */
 526         if (as->volume)
 527                 afs_clear_callback_interests(net, as->volume->servers);
 528         kill_anon_super(sb);
 529         if (as->volume)
 530                 afs_deactivate_volume(as->volume);
 531         afs_destroy_sbi(as);
 532 }
 533
 534 /*
 535  * Get an AFS superblock and root directory.
 536  */
 537 static int afs_get_tree(struct fs_context *fc)
 538 {
 539         struct afs_fs_context *ctx = fc->fs_private;
 540         struct super_block *sb;
 541         struct afs_super_info *as;
 542         int ret;
 543
 544         ret = afs_validate_fc(fc);
 545         if (ret)
 546                 goto error;
 547
 548         _enter("");
 549
 550         /* allocate a superblock info record */
 551         ret = -ENOMEM;
 552         as = afs_alloc_sbi(fc);
 553         if (!as)
 554                 goto error;
 555         fc->s_fs_info = as;
 556
 557         /* allocate a deviceless superblock */
 558         sb = sget_fc(fc,
 559                      as->dyn_root ? afs_dynroot_test_super : afs_test_super,
 560                      afs_set_super);
 561         if (IS_ERR(sb)) {
 562                 ret = PTR_ERR(sb);
 563                 goto error;
 564         }
 565
 566         if (!sb->s_root) {
 567                 /* initial superblock/root creation */
 568                 _debug("create");
 569                 ret = afs_fill_super(sb, ctx);
 570                 if (ret < 0)
 571                         goto error_sb;
 572                 sb->s_flags |= SB_ACTIVE;
 573         } else {
 574                 _debug("reuse");
 575                 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
 576         }
 577
 578         fc->root = dget(sb->s_root);
 579         trace_afs_get_tree(as->cell, as->volume);
 580         _leave(" = 0 [%p]", sb);
 581         return 0;
 582
 583 error_sb:
 584         deactivate_locked_super(sb);
 585 error:
 586         _leave(" = %d", ret);
 587         return ret;
 588 }
 589
 590 static void afs_free_fc(struct fs_context *fc)
 591 {
 592         struct afs_fs_context *ctx = fc->fs_private;
 593
 594         afs_destroy_sbi(fc->s_fs_info);
 595         afs_put_volume(ctx->cell, ctx->volume);
 596         afs_put_cell(ctx->net, ctx->cell);
 597         key_put(ctx->key);
 598         kfree(ctx);
 599 }
 600
 601 static const struct fs_context_operations afs_context_ops = {
 602         .free           = afs_free_fc,
 603         .parse_param    = afs_parse_param,
 604         .get_tree       = afs_get_tree,
 605 };
 606
 607 /*
 608  * Set up the filesystem mount context.
 609  */
 610 static int afs_init_fs_context(struct fs_context *fc)
 611 {
 612         struct afs_fs_context *ctx;
 613         struct afs_cell *cell;
 614
 615         ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
 616         if (!ctx)
 617                 return -ENOMEM;
 618
 619         ctx->type = AFSVL_ROVOL;
 620         ctx->net = afs_net(fc->net_ns);
 621
 622         /* Default to the workstation cell. */
 623         rcu_read_lock();
 624         cell = afs_lookup_cell_rcu(ctx->net, NULL, 0);
 625         rcu_read_unlock();
 626         if (IS_ERR(cell))
 627                 cell = NULL;
 628         ctx->cell = cell;
 629
 630         fc->fs_private = ctx;
 631         fc->ops = &afs_context_ops;
 632         return 0;
 633 }
 634
 635 /*
 636  * Initialise an inode cache slab element prior to any use.  Note that
 637  * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
 638  * inode to another.
 639  */
 640 static void afs_i_init_once(void *_vnode)
 641 {
 642         struct afs_vnode *vnode = _vnode;
 643
 644         memset(vnode, 0, sizeof(*vnode));
 645         inode_init_once(&vnode->vfs_inode);
 646         mutex_init(&vnode->io_lock);
 647         init_rwsem(&vnode->validate_lock);
 648         spin_lock_init(&vnode->wb_lock);
 649         spin_lock_init(&vnode->lock);
 650         INIT_LIST_HEAD(&vnode->wb_keys);
 651         INIT_LIST_HEAD(&vnode->pending_locks);
 652         INIT_LIST_HEAD(&vnode->granted_locks);
 653         INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
 654         seqlock_init(&vnode->cb_lock);
 655 }
 656
 657 /*
 658  * allocate an AFS inode struct from our slab cache
 659  */
 660 static struct inode *afs_alloc_inode(struct super_block *sb)
 661 {
 662         struct afs_vnode *vnode;
 663
 664         vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
 665         if (!vnode)
 666                 return NULL;
 667
 668         atomic_inc(&afs_count_active_inodes);
 669
 670         /* Reset anything that shouldn't leak from one inode to the next. */
 671         memset(&vnode->fid, 0, sizeof(vnode->fid));
 672         memset(&vnode->status, 0, sizeof(vnode->status));
 673
 674         vnode->volume           = NULL;
 675         vnode->lock_key         = NULL;
 676         vnode->permit_cache     = NULL;
 677         RCU_INIT_POINTER(vnode->cb_interest, NULL);
 678 #ifdef CONFIG_AFS_FSCACHE
 679         vnode->cache            = NULL;
 680 #endif
 681
 682         vnode->flags            = 1 << AFS_VNODE_UNSET;
 683         vnode->lock_state       = AFS_VNODE_LOCK_NONE;
 684
 685         init_rwsem(&vnode->rmdir_lock);
 686
 687         _leave(" = %p", &vnode->vfs_inode);
 688         return &vnode->vfs_inode;
 689 }
 690
 691 static void afs_free_inode(struct inode *inode)
 692 {
 693         kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
 694 }
 695
 696 /*
 697  * destroy an AFS inode struct
 698  */
 699 static void afs_destroy_inode(struct inode *inode)
 700 {
 701         struct afs_vnode *vnode = AFS_FS_I(inode);
 702
 703         _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
 704
 705         _debug("DESTROY INODE %p", inode);
 706
 707         ASSERTCMP(rcu_access_pointer(vnode->cb_interest), ==, NULL);
 708
 709         atomic_dec(&afs_count_active_inodes);
 710 }
 711
 712 /*
 713  * return information about an AFS volume
 714  */
 715 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
 716 {
 717         struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
 718         struct afs_fs_cursor fc;
 719         struct afs_volume_status vs;
 720         struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
 721         struct key *key;
 722         int ret;
 723
 724         buf->f_type     = dentry->d_sb->s_magic;
 725         buf->f_bsize    = AFS_BLOCK_SIZE;
 726         buf->f_namelen  = AFSNAMEMAX - 1;
 727
 728         if (as->dyn_root) {
 729                 buf->f_blocks   = 1;
 730                 buf->f_bavail   = 0;
 731                 buf->f_bfree    = 0;
 732                 return 0;
 733         }
 734
 735         key = afs_request_key(vnode->volume->cell);
 736         if (IS_ERR(key))
 737                 return PTR_ERR(key);
 738
 739         ret = -ERESTARTSYS;
 740         if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
 741                 fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
 742                 while (afs_select_fileserver(&fc)) {
 743                         fc.cb_break = afs_calc_vnode_cb_break(vnode);
 744                         afs_fs_get_volume_status(&fc, &vs);
 745                 }
 746
 747                 afs_check_for_remote_deletion(&fc, fc.vnode);
 748                 ret = afs_end_vnode_operation(&fc);
 749         }
 750
 751         key_put(key);
 752
 753         if (ret == 0) {
 754                 if (vs.max_quota == 0)
 755                         buf->f_blocks = vs.part_max_blocks;
 756                 else
 757                         buf->f_blocks = vs.max_quota;
 758                 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
 759         }
 760
 761         return ret;
 762 }