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 int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
  37 static int afs_show_devname(struct seq_file *m, struct dentry *root);
  38 static int afs_show_options(struct seq_file *m, struct dentry *root);
  39 static int afs_init_fs_context(struct fs_context *fc);
  40 static const struct fs_parameter_description afs_fs_parameters;
  41
  42 struct file_system_type afs_fs_type = {
  43         .owner                  = THIS_MODULE,
  44         .name                   = "afs",
  45         .init_fs_context        = afs_init_fs_context,
  46         .parameters             = &afs_fs_parameters,
  47         .kill_sb                = afs_kill_super,
  48         .fs_flags               = FS_RENAME_DOES_D_MOVE,
  49 };
  50 MODULE_ALIAS_FS("afs");
  51
  52 int afs_net_id;
  53
  54 static const struct super_operations afs_super_ops = {
  55         .statfs         = afs_statfs,
  56         .alloc_inode    = afs_alloc_inode,
  57         .drop_inode     = afs_drop_inode,
  58         .destroy_inode  = afs_destroy_inode,
  59         .evict_inode    = afs_evict_inode,
  60         .show_devname   = afs_show_devname,
  61         .show_options   = afs_show_options,
  62 };
  63
  64 static struct kmem_cache *afs_inode_cachep;
  65 static atomic_t afs_count_active_inodes;
  66
  67 enum afs_param {
  68         Opt_autocell,
  69         Opt_dyn,
  70         Opt_flock,
  71         Opt_source,
  72 };
  73
  74 static const struct fs_parameter_spec afs_param_specs[] = {
  75         fsparam_flag  ("autocell",      Opt_autocell),
  76         fsparam_flag  ("dyn",           Opt_dyn),
  77         fsparam_enum  ("flock",         Opt_flock),
  78         fsparam_string("source",        Opt_source),
  79         {}
  80 };
  81
  82 static const struct fs_parameter_enum afs_param_enums[] = {
  83         { Opt_flock,    "local",        afs_flock_mode_local },
  84         { Opt_flock,    "openafs",      afs_flock_mode_openafs },
  85         { Opt_flock,    "strict",       afs_flock_mode_strict },
  86         { Opt_flock,    "write",        afs_flock_mode_write },
  87         {}
  88 };
  89
  90 static const struct fs_parameter_description afs_fs_parameters = {
  91         .name           = "kAFS",
  92         .specs          = afs_param_specs,
  93         .enums          = afs_param_enums,
  94 };
  95
  96 /*
  97  * initialise the filesystem
  98  */
  99 int __init afs_fs_init(void)
 100 {
 101         int ret;
 102
 103         _enter("");
 104
 105         /* create ourselves an inode cache */
 106         atomic_set(&afs_count_active_inodes, 0);
 107
 108         ret = -ENOMEM;
 109         afs_inode_cachep = kmem_cache_create("afs_inode_cache",
 110                                              sizeof(struct afs_vnode),
 111                                              0,
 112                                              SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
 113                                              afs_i_init_once);
 114         if (!afs_inode_cachep) {
 115                 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
 116                 return ret;
 117         }
 118
 119         /* now export our filesystem to lesser mortals */
 120         ret = register_filesystem(&afs_fs_type);
 121         if (ret < 0) {
 122                 kmem_cache_destroy(afs_inode_cachep);
 123                 _leave(" = %d", ret);
 124                 return ret;
 125         }
 126
 127         _leave(" = 0");
 128         return 0;
 129 }
 130
 131 /*
 132  * clean up the filesystem
 133  */
 134 void afs_fs_exit(void)
 135 {
 136         _enter("");
 137
 138         afs_mntpt_kill_timer();
 139         unregister_filesystem(&afs_fs_type);
 140
 141         if (atomic_read(&afs_count_active_inodes) != 0) {
 142                 printk("kAFS: %d active inode objects still present\n",
 143                        atomic_read(&afs_count_active_inodes));
 144                 BUG();
 145         }
 146
 147         /*
 148          * Make sure all delayed rcu free inodes are flushed before we
 149          * destroy cache.
 150          */
 151         rcu_barrier();
 152         kmem_cache_destroy(afs_inode_cachep);
 153         _leave("");
 154 }
 155
 156 /*
 157  * Display the mount device name in /proc/mounts.
 158  */
 159 static int afs_show_devname(struct seq_file *m, struct dentry *root)
 160 {
 161         struct afs_super_info *as = AFS_FS_S(root->d_sb);
 162         struct afs_volume *volume = as->volume;
 163         struct afs_cell *cell = as->cell;
 164         const char *suf = "";
 165         char pref = '%';
 166
 167         if (as->dyn_root) {
 168                 seq_puts(m, "none");
 169                 return 0;
 170         }
 171
 172         switch (volume->type) {
 173         case AFSVL_RWVOL:
 174                 break;
 175         case AFSVL_ROVOL:
 176                 pref = '#';
 177                 if (volume->type_force)
 178                         suf = ".readonly";
 179                 break;
 180         case AFSVL_BACKVOL:
 181                 pref = '#';
 182                 suf = ".backup";
 183                 break;
 184         }
 185
 186         seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
 187         return 0;
 188 }
 189
 190 /*
 191  * Display the mount options in /proc/mounts.
 192  */
 193 static int afs_show_options(struct seq_file *m, struct dentry *root)
 194 {
 195         struct afs_super_info *as = AFS_FS_S(root->d_sb);
 196         const char *p = NULL;
 197
 198         if (as->dyn_root)
 199                 seq_puts(m, ",dyn");
 200         if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
 201                 seq_puts(m, ",autocell");
 202         switch (as->flock_mode) {
 203         case afs_flock_mode_unset:      break;
 204         case afs_flock_mode_local:      p = "local";    break;
 205         case afs_flock_mode_openafs:    p = "openafs";  break;
 206         case afs_flock_mode_strict:     p = "strict";   break;
 207         case afs_flock_mode_write:      p = "write";    break;
 208         }
 209         if (p)
 210                 seq_printf(m, ",flock=%s", p);
 211
 212         return 0;
 213 }
 214
 215 /*
 216  * Parse the source name to get cell name, volume name, volume type and R/W
 217  * selector.
 218  *
 219  * This can be one of the following:
 220  *      "%[cell:]volume[.]"             R/W volume
 221  *      "#[cell:]volume[.]"             R/O or R/W volume (R/O parent),
 222  *                                       or R/W (R/W parent) volume
 223  *      "%[cell:]volume.readonly"       R/O volume
 224  *      "#[cell:]volume.readonly"       R/O volume
 225  *      "%[cell:]volume.backup"         Backup volume
 226  *      "#[cell:]volume.backup"         Backup volume
 227  */
 228 static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
 229 {
 230         struct afs_fs_context *ctx = fc->fs_private;
 231         struct afs_cell *cell;
 232         const char *cellname, *suffix, *name = param->string;
 233         int cellnamesz;
 234
 235         _enter(",%s", name);
 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_put_cell(ctx->net, ctx->cell);
 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 key *key;
 360
 361         if (!ctx->dyn_root) {
 362                 if (ctx->no_cell) {
 363                         pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
 364                         return -EINVAL;
 365                 }
 366
 367                 if (!ctx->cell) {
 368                         pr_warn("kAFS: No cell specified\n");
 369                         return -EDESTADDRREQ;
 370                 }
 371
 372                 /* We try to do the mount securely. */
 373                 key = afs_request_key(ctx->cell);
 374                 if (IS_ERR(key))
 375                         return PTR_ERR(key);
 376
 377                 ctx->key = key;
 378
 379                 if (ctx->volume) {
 380                         afs_put_volume(ctx->cell, ctx->volume);
 381                         ctx->volume = NULL;
 382                 }
 383
 384                 volume = afs_create_volume(ctx);
 385                 if (IS_ERR(volume))
 386                         return PTR_ERR(volume);
 387
 388                 ctx->volume = volume;
 389         }
 390
 391         return 0;
 392 }
 393
 394 /*
 395  * check a superblock to see if it's the one we're looking for
 396  */
 397 static int afs_test_super(struct super_block *sb, struct fs_context *fc)
 398 {
 399         struct afs_fs_context *ctx = fc->fs_private;
 400         struct afs_super_info *as = AFS_FS_S(sb);
 401
 402         return (as->net_ns == fc->net_ns &&
 403                 as->volume &&
 404                 as->volume->vid == ctx->volume->vid &&
 405                 !as->dyn_root);
 406 }
 407
 408 static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
 409 {
 410         struct afs_super_info *as = AFS_FS_S(sb);
 411
 412         return (as->net_ns == fc->net_ns &&
 413                 as->dyn_root);
 414 }
 415
 416 static int afs_set_super(struct super_block *sb, struct fs_context *fc)
 417 {
 418         return set_anon_super(sb, NULL);
 419 }
 420
 421 /*
 422  * fill in the superblock
 423  */
 424 static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 425 {
 426         struct afs_super_info *as = AFS_FS_S(sb);
 427         struct afs_fid fid;
 428         struct inode *inode = NULL;
 429         int ret;
 430
 431         _enter("");
 432
 433         /* fill in the superblock */
 434         sb->s_blocksize         = PAGE_SIZE;
 435         sb->s_blocksize_bits    = PAGE_SHIFT;
 436         sb->s_magic             = AFS_FS_MAGIC;
 437         sb->s_op                = &afs_super_ops;
 438         if (!as->dyn_root)
 439                 sb->s_xattr     = afs_xattr_handlers;
 440         ret = super_setup_bdi(sb);
 441         if (ret)
 442                 return ret;
 443         sb->s_bdi->ra_pages     = VM_READAHEAD_PAGES;
 444
 445         /* allocate the root inode and dentry */
 446         if (as->dyn_root) {
 447                 inode = afs_iget_pseudo_dir(sb, true);
 448                 sb->s_flags     |= SB_RDONLY;
 449         } else {
 450                 sprintf(sb->s_id, "%llu", as->volume->vid);
 451                 afs_activate_volume(as->volume);
 452                 fid.vid         = as->volume->vid;
 453                 fid.vnode       = 1;
 454                 fid.vnode_hi    = 0;
 455                 fid.unique      = 1;
 456                 inode = afs_iget(sb, ctx->key, &fid, NULL, NULL, NULL, NULL);
 457         }
 458
 459         if (IS_ERR(inode))
 460                 return PTR_ERR(inode);
 461
 462         if (ctx->autocell || as->dyn_root)
 463                 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
 464
 465         ret = -ENOMEM;
 466         sb->s_root = d_make_root(inode);
 467         if (!sb->s_root)
 468                 goto error;
 469
 470         if (as->dyn_root) {
 471                 sb->s_d_op = &afs_dynroot_dentry_operations;
 472                 ret = afs_dynroot_populate(sb);
 473                 if (ret < 0)
 474                         goto error;
 475         } else {
 476                 sb->s_d_op = &afs_fs_dentry_operations;
 477         }
 478
 479         _leave(" = 0");
 480         return 0;
 481
 482 error:
 483         _leave(" = %d", ret);
 484         return ret;
 485 }
 486
 487 static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
 488 {
 489         struct afs_fs_context *ctx = fc->fs_private;
 490         struct afs_super_info *as;
 491
 492         as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
 493         if (as) {
 494                 as->net_ns = get_net(fc->net_ns);
 495                 as->flock_mode = ctx->flock_mode;
 496                 if (ctx->dyn_root) {
 497                         as->dyn_root = true;
 498                 } else {
 499                         as->cell = afs_get_cell(ctx->cell);
 500                         as->volume = __afs_get_volume(ctx->volume);
 501                 }
 502         }
 503         return as;
 504 }
 505
 506 static void afs_destroy_sbi(struct afs_super_info *as)
 507 {
 508         if (as) {
 509                 afs_put_volume(as->cell, as->volume);
 510                 afs_put_cell(afs_net(as->net_ns), as->cell);
 511                 put_net(as->net_ns);
 512                 kfree(as);
 513         }
 514 }
 515
 516 static void afs_kill_super(struct super_block *sb)
 517 {
 518         struct afs_super_info *as = AFS_FS_S(sb);
 519         struct afs_net *net = afs_net(as->net_ns);
 520
 521         if (as->dyn_root)
 522                 afs_dynroot_depopulate(sb);
 523
 524         /* Clear the callback interests (which will do ilookup5) before
 525          * deactivating the superblock.
 526          */
 527         if (as->volume)
 528                 afs_clear_callback_interests(net, as->volume->servers);
 529         kill_anon_super(sb);
 530         if (as->volume)
 531                 afs_deactivate_volume(as->volume);
 532         afs_destroy_sbi(as);
 533 }
 534
 535 /*
 536  * Get an AFS superblock and root directory.
 537  */
 538 static int afs_get_tree(struct fs_context *fc)
 539 {
 540         struct afs_fs_context *ctx = fc->fs_private;
 541         struct super_block *sb;
 542         struct afs_super_info *as;
 543         int ret;
 544
 545         ret = afs_validate_fc(fc);
 546         if (ret)
 547                 goto error;
 548
 549         _enter("");
 550
 551         /* allocate a superblock info record */
 552         ret = -ENOMEM;
 553         as = afs_alloc_sbi(fc);
 554         if (!as)
 555                 goto error;
 556         fc->s_fs_info = as;
 557
 558         /* allocate a deviceless superblock */
 559         sb = sget_fc(fc,
 560                      as->dyn_root ? afs_dynroot_test_super : afs_test_super,
 561                      afs_set_super);
 562         if (IS_ERR(sb)) {
 563                 ret = PTR_ERR(sb);
 564                 goto error;
 565         }
 566
 567         if (!sb->s_root) {
 568                 /* initial superblock/root creation */
 569                 _debug("create");
 570                 ret = afs_fill_super(sb, ctx);
 571                 if (ret < 0)
 572                         goto error_sb;
 573                 sb->s_flags |= SB_ACTIVE;
 574         } else {
 575                 _debug("reuse");
 576                 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
 577         }
 578
 579         fc->root = dget(sb->s_root);
 580         trace_afs_get_tree(as->cell, as->volume);
 581         _leave(" = 0 [%p]", sb);
 582         return 0;
 583
 584 error_sb:
 585         deactivate_locked_super(sb);
 586 error:
 587         _leave(" = %d", ret);
 588         return ret;
 589 }
 590
 591 static void afs_free_fc(struct fs_context *fc)
 592 {
 593         struct afs_fs_context *ctx = fc->fs_private;
 594
 595         afs_destroy_sbi(fc->s_fs_info);
 596         afs_put_volume(ctx->cell, ctx->volume);
 597         afs_put_cell(ctx->net, ctx->cell);
 598         key_put(ctx->key);
 599         kfree(ctx);
 600 }
 601
 602 static const struct fs_context_operations afs_context_ops = {
 603         .free           = afs_free_fc,
 604         .parse_param    = afs_parse_param,
 605         .get_tree       = afs_get_tree,
 606 };
 607
 608 /*
 609  * Set up the filesystem mount context.
 610  */
 611 static int afs_init_fs_context(struct fs_context *fc)
 612 {
 613         struct afs_fs_context *ctx;
 614         struct afs_cell *cell;
 615
 616         ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
 617         if (!ctx)
 618                 return -ENOMEM;
 619
 620         ctx->type = AFSVL_ROVOL;
 621         ctx->net = afs_net(fc->net_ns);
 622
 623         /* Default to the workstation cell. */
 624         rcu_read_lock();
 625         cell = afs_lookup_cell_rcu(ctx->net, NULL, 0);
 626         rcu_read_unlock();
 627         if (IS_ERR(cell))
 628                 cell = NULL;
 629         ctx->cell = cell;
 630
 631         fc->fs_private = ctx;
 632         fc->ops = &afs_context_ops;
 633         return 0;
 634 }
 635
 636 /*
 637  * Initialise an inode cache slab element prior to any use.  Note that
 638  * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
 639  * inode to another.
 640  */
 641 static void afs_i_init_once(void *_vnode)
 642 {
 643         struct afs_vnode *vnode = _vnode;
 644
 645         memset(vnode, 0, sizeof(*vnode));
 646         inode_init_once(&vnode->vfs_inode);
 647         mutex_init(&vnode->io_lock);
 648         init_rwsem(&vnode->validate_lock);
 649         spin_lock_init(&vnode->wb_lock);
 650         spin_lock_init(&vnode->lock);
 651         INIT_LIST_HEAD(&vnode->wb_keys);
 652         INIT_LIST_HEAD(&vnode->pending_locks);
 653         INIT_LIST_HEAD(&vnode->granted_locks);
 654         INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
 655         seqlock_init(&vnode->cb_lock);
 656 }
 657
 658 /*
 659  * allocate an AFS inode struct from our slab cache
 660  */
 661 static struct inode *afs_alloc_inode(struct super_block *sb)
 662 {
 663         struct afs_vnode *vnode;
 664
 665         vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
 666         if (!vnode)
 667                 return NULL;
 668
 669         atomic_inc(&afs_count_active_inodes);
 670
 671         /* Reset anything that shouldn't leak from one inode to the next. */
 672         memset(&vnode->fid, 0, sizeof(vnode->fid));
 673         memset(&vnode->status, 0, sizeof(vnode->status));
 674
 675         vnode->volume           = NULL;
 676         vnode->lock_key         = NULL;
 677         vnode->permit_cache     = NULL;
 678         vnode->cb_interest      = NULL;
 679 #ifdef CONFIG_AFS_FSCACHE
 680         vnode->cache            = NULL;
 681 #endif
 682
 683         vnode->flags            = 1 << AFS_VNODE_UNSET;
 684         vnode->cb_type          = 0;
 685         vnode->lock_state       = AFS_VNODE_LOCK_NONE;
 686
 687         init_rwsem(&vnode->rmdir_lock);
 688
 689         _leave(" = %p", &vnode->vfs_inode);
 690         return &vnode->vfs_inode;
 691 }
 692
 693 static void afs_i_callback(struct rcu_head *head)
 694 {
 695         struct inode *inode = container_of(head, struct inode, i_rcu);
 696         struct afs_vnode *vnode = AFS_FS_I(inode);
 697         kmem_cache_free(afs_inode_cachep, vnode);
 698 }
 699
 700 /*
 701  * destroy an AFS inode struct
 702  */
 703 static void afs_destroy_inode(struct inode *inode)
 704 {
 705         struct afs_vnode *vnode = AFS_FS_I(inode);
 706
 707         _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
 708
 709         _debug("DESTROY INODE %p", inode);
 710
 711         ASSERTCMP(vnode->cb_interest, ==, NULL);
 712
 713         call_rcu(&inode->i_rcu, afs_i_callback);
 714         atomic_dec(&afs_count_active_inodes);
 715 }
 716
 717 /*
 718  * return information about an AFS volume
 719  */
 720 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
 721 {
 722         struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
 723         struct afs_fs_cursor fc;
 724         struct afs_volume_status vs;
 725         struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
 726         struct key *key;
 727         int ret;
 728
 729         buf->f_type     = dentry->d_sb->s_magic;
 730         buf->f_bsize    = AFS_BLOCK_SIZE;
 731         buf->f_namelen  = AFSNAMEMAX - 1;
 732
 733         if (as->dyn_root) {
 734                 buf->f_blocks   = 1;
 735                 buf->f_bavail   = 0;
 736                 buf->f_bfree    = 0;
 737                 return 0;
 738         }
 739
 740         key = afs_request_key(vnode->volume->cell);
 741         if (IS_ERR(key))
 742                 return PTR_ERR(key);
 743
 744         ret = -ERESTARTSYS;
 745         if (afs_begin_vnode_operation(&fc, vnode, key)) {
 746                 fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
 747                 while (afs_select_fileserver(&fc)) {
 748                         fc.cb_break = afs_calc_vnode_cb_break(vnode);
 749                         afs_fs_get_volume_status(&fc, &vs);
 750                 }
 751
 752                 afs_check_for_remote_deletion(&fc, fc.vnode);
 753                 afs_vnode_commit_status(&fc, vnode, fc.cb_break);
 754                 ret = afs_end_vnode_operation(&fc);
 755         }
 756
 757         key_put(key);
 758
 759         if (ret == 0) {
 760                 if (vs.max_quota == 0)
 761                         buf->f_blocks = vs.part_max_blocks;
 762                 else
 763                         buf->f_blocks = vs.max_quota;
 764                 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
 765         }
 766
 767         return ret;
 768 }