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