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         .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         if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
 198                 seq_puts(m, ",autocell");
 199         switch (as->flock_mode) {
 200         case afs_flock_mode_unset:      break;
 201         case afs_flock_mode_local:      p = "local";    break;
 202         case afs_flock_mode_openafs:    p = "openafs";  break;
 203         case afs_flock_mode_strict:     p = "strict";   break;
 204         case afs_flock_mode_write:      p = "write";    break;
 205         }
 206         if (p)
 207                 seq_printf(m, ",flock=%s", p);
 208
 209         return 0;
 210 }
 211
 212 /*
 213  * Parse the source name to get cell name, volume name, volume type and R/W
 214  * selector.
 215  *
 216  * This can be one of the following:
 217  *      "%[cell:]volume[.]"             R/W volume
 218  *      "#[cell:]volume[.]"             R/O or R/W volume (R/O parent),
 219  *                                       or R/W (R/W parent) volume
 220  *      "%[cell:]volume.readonly"       R/O volume
 221  *      "#[cell:]volume.readonly"       R/O volume
 222  *      "%[cell:]volume.backup"         Backup volume
 223  *      "#[cell:]volume.backup"         Backup volume
 224  */
 225 static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
 226 {
 227         struct afs_fs_context *ctx = fc->fs_private;
 228         struct afs_cell *cell;
 229         const char *cellname, *suffix, *name = param->string;
 230         int cellnamesz;
 231
 232         _enter(",%s", name);
 233
 234         if (fc->source)
 235                 return invalf(fc, "kAFS: Multiple sources not supported");
 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_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_parse);
 302                 afs_see_cell(cell, afs_cell_trace_see_source);
 303                 ctx->cell = cell;
 304         }
 305
 306         _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
 307                ctx->cell->name, ctx->cell,
 308                ctx->volnamesz, ctx->volnamesz, ctx->volname,
 309                suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
 310
 311         fc->source = param->string;
 312         param->string = NULL;
 313         return 0;
 314 }
 315
 316 /*
 317  * Parse a single mount parameter.
 318  */
 319 static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 320 {
 321         struct fs_parse_result result;
 322         struct afs_fs_context *ctx = fc->fs_private;
 323         int opt;
 324
 325         opt = fs_parse(fc, afs_fs_parameters, param, &result);
 326         if (opt < 0)
 327                 return opt;
 328
 329         switch (opt) {
 330         case Opt_source:
 331                 return afs_parse_source(fc, param);
 332
 333         case Opt_autocell:
 334                 ctx->autocell = true;
 335                 break;
 336
 337         case Opt_dyn:
 338                 ctx->dyn_root = true;
 339                 break;
 340
 341         case Opt_flock:
 342                 ctx->flock_mode = result.uint_32;
 343                 break;
 344
 345         default:
 346                 return -EINVAL;
 347         }
 348
 349         _leave(" = 0");
 350         return 0;
 351 }
 352
 353 /*
 354  * Validate the options, get the cell key and look up the volume.
 355  */
 356 static int afs_validate_fc(struct fs_context *fc)
 357 {
 358         struct afs_fs_context *ctx = fc->fs_private;
 359         struct afs_volume *volume;
 360         struct afs_cell *cell;
 361         struct key *key;
 362         int ret;
 363
 364         if (!ctx->dyn_root) {
 365                 if (ctx->no_cell) {
 366                         pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
 367                         return -EINVAL;
 368                 }
 369
 370                 if (!ctx->cell) {
 371                         pr_warn("kAFS: No cell specified\n");
 372                         return -EDESTADDRREQ;
 373                 }
 374
 375         reget_key:
 376                 /* We try to do the mount securely. */
 377                 key = afs_request_key(ctx->cell);
 378                 if (IS_ERR(key))
 379                         return PTR_ERR(key);
 380
 381                 ctx->key = key;
 382
 383                 if (ctx->volume) {
 384                         afs_put_volume(ctx->volume, afs_volume_trace_put_validate_fc);
 385                         ctx->volume = NULL;
 386                 }
 387
 388                 if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &ctx->cell->flags)) {
 389                         ret = afs_cell_detect_alias(ctx->cell, key);
 390                         if (ret < 0)
 391                                 return ret;
 392                         if (ret == 1) {
 393                                 _debug("switch to alias");
 394                                 key_put(ctx->key);
 395                                 ctx->key = NULL;
 396                                 cell = afs_use_cell(ctx->cell->alias_of,
 397                                                     afs_cell_trace_use_fc_alias);
 398                                 afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
 399                                 ctx->cell = cell;
 400                                 goto reget_key;
 401                         }
 402                 }
 403
 404                 volume = afs_create_volume(ctx);
 405                 if (IS_ERR(volume))
 406                         return PTR_ERR(volume);
 407
 408                 ctx->volume = volume;
 409                 if (volume->type != AFSVL_RWVOL) {
 410                         ctx->flock_mode = afs_flock_mode_local;
 411                         fc->sb_flags |= SB_RDONLY;
 412                 }
 413         }
 414
 415         return 0;
 416 }
 417
 418 /*
 419  * check a superblock to see if it's the one we're looking for
 420  */
 421 static int afs_test_super(struct super_block *sb, struct fs_context *fc)
 422 {
 423         struct afs_fs_context *ctx = fc->fs_private;
 424         struct afs_super_info *as = AFS_FS_S(sb);
 425
 426         return (as->net_ns == fc->net_ns &&
 427                 as->volume &&
 428                 as->volume->vid == ctx->volume->vid &&
 429                 as->cell == ctx->cell &&
 430                 !as->dyn_root);
 431 }
 432
 433 static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
 434 {
 435         struct afs_super_info *as = AFS_FS_S(sb);
 436
 437         return (as->net_ns == fc->net_ns &&
 438                 as->dyn_root);
 439 }
 440
 441 static int afs_set_super(struct super_block *sb, struct fs_context *fc)
 442 {
 443         return set_anon_super(sb, NULL);
 444 }
 445
 446 /*
 447  * fill in the superblock
 448  */
 449 static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 450 {
 451         struct afs_super_info *as = AFS_FS_S(sb);
 452         struct inode *inode = NULL;
 453         int ret;
 454
 455         _enter("");
 456
 457         /* fill in the superblock */
 458         sb->s_blocksize         = PAGE_SIZE;
 459         sb->s_blocksize_bits    = PAGE_SHIFT;
 460         sb->s_maxbytes          = MAX_LFS_FILESIZE;
 461         sb->s_magic             = AFS_FS_MAGIC;
 462         sb->s_op                = &afs_super_ops;
 463         if (!as->dyn_root)
 464                 sb->s_xattr     = afs_xattr_handlers;
 465         ret = super_setup_bdi(sb);
 466         if (ret)
 467                 return ret;
 468
 469         /* allocate the root inode and dentry */
 470         if (as->dyn_root) {
 471                 inode = afs_iget_pseudo_dir(sb, true);
 472         } else {
 473                 sprintf(sb->s_id, "%llu", as->volume->vid);
 474                 afs_activate_volume(as->volume);
 475                 inode = afs_root_iget(sb, ctx->key);
 476         }
 477
 478         if (IS_ERR(inode))
 479                 return PTR_ERR(inode);
 480
 481         if (ctx->autocell || as->dyn_root)
 482                 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
 483
 484         ret = -ENOMEM;
 485         sb->s_root = d_make_root(inode);
 486         if (!sb->s_root)
 487                 goto error;
 488
 489         if (as->dyn_root) {
 490                 sb->s_d_op = &afs_dynroot_dentry_operations;
 491                 ret = afs_dynroot_populate(sb);
 492                 if (ret < 0)
 493                         goto error;
 494         } else {
 495                 sb->s_d_op = &afs_fs_dentry_operations;
 496                 rcu_assign_pointer(as->volume->sb, sb);
 497         }
 498
 499         _leave(" = 0");
 500         return 0;
 501
 502 error:
 503         _leave(" = %d", ret);
 504         return ret;
 505 }
 506
 507 static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
 508 {
 509         struct afs_fs_context *ctx = fc->fs_private;
 510         struct afs_super_info *as;
 511
 512         as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
 513         if (as) {
 514                 as->net_ns = get_net(fc->net_ns);
 515                 as->flock_mode = ctx->flock_mode;
 516                 if (ctx->dyn_root) {
 517                         as->dyn_root = true;
 518                 } else {
 519                         as->cell = afs_use_cell(ctx->cell, afs_cell_trace_use_sbi);
 520                         as->volume = afs_get_volume(ctx->volume,
 521                                                     afs_volume_trace_get_alloc_sbi);
 522                 }
 523         }
 524         return as;
 525 }
 526
 527 static void afs_destroy_sbi(struct afs_super_info *as)
 528 {
 529         if (as) {
 530                 struct afs_net *net = afs_net(as->net_ns);
 531                 afs_put_volume(as->volume, afs_volume_trace_put_destroy_sbi);
 532                 afs_unuse_cell(net, as->cell, afs_cell_trace_unuse_sbi);
 533                 put_net(as->net_ns);
 534                 kfree(as);
 535         }
 536 }
 537
 538 static void afs_kill_super(struct super_block *sb)
 539 {
 540         struct afs_super_info *as = AFS_FS_S(sb);
 541
 542         if (as->dyn_root)
 543                 afs_dynroot_depopulate(sb);
 544
 545         /* Clear the callback interests (which will do ilookup5) before
 546          * deactivating the superblock.
 547          */
 548         if (as->volume)
 549                 rcu_assign_pointer(as->volume->sb, NULL);
 550         kill_anon_super(sb);
 551         if (as->volume)
 552                 afs_deactivate_volume(as->volume);
 553         afs_destroy_sbi(as);
 554 }
 555
 556 /*
 557  * Get an AFS superblock and root directory.
 558  */
 559 static int afs_get_tree(struct fs_context *fc)
 560 {
 561         struct afs_fs_context *ctx = fc->fs_private;
 562         struct super_block *sb;
 563         struct afs_super_info *as;
 564         int ret;
 565
 566         ret = afs_validate_fc(fc);
 567         if (ret)
 568                 goto error;
 569
 570         _enter("");
 571
 572         /* allocate a superblock info record */
 573         ret = -ENOMEM;
 574         as = afs_alloc_sbi(fc);
 575         if (!as)
 576                 goto error;
 577         fc->s_fs_info = as;
 578
 579         /* allocate a deviceless superblock */
 580         sb = sget_fc(fc,
 581                      as->dyn_root ? afs_dynroot_test_super : afs_test_super,
 582                      afs_set_super);
 583         if (IS_ERR(sb)) {
 584                 ret = PTR_ERR(sb);
 585                 goto error;
 586         }
 587
 588         if (!sb->s_root) {
 589                 /* initial superblock/root creation */
 590                 _debug("create");
 591                 ret = afs_fill_super(sb, ctx);
 592                 if (ret < 0)
 593                         goto error_sb;
 594                 sb->s_flags |= SB_ACTIVE;
 595         } else {
 596                 _debug("reuse");
 597                 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
 598         }
 599
 600         fc->root = dget(sb->s_root);
 601         trace_afs_get_tree(as->cell, as->volume);
 602         _leave(" = 0 [%p]", sb);
 603         return 0;
 604
 605 error_sb:
 606         deactivate_locked_super(sb);
 607 error:
 608         _leave(" = %d", ret);
 609         return ret;
 610 }
 611
 612 static void afs_free_fc(struct fs_context *fc)
 613 {
 614         struct afs_fs_context *ctx = fc->fs_private;
 615
 616         afs_destroy_sbi(fc->s_fs_info);
 617         afs_put_volume(ctx->volume, afs_volume_trace_put_free_fc);
 618         afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
 619         key_put(ctx->key);
 620         kfree(ctx);
 621 }
 622
 623 static const struct fs_context_operations afs_context_ops = {
 624         .free           = afs_free_fc,
 625         .parse_param    = afs_parse_param,
 626         .get_tree       = afs_get_tree,
 627 };
 628
 629 /*
 630  * Set up the filesystem mount context.
 631  */
 632 static int afs_init_fs_context(struct fs_context *fc)
 633 {
 634         struct afs_fs_context *ctx;
 635         struct afs_cell *cell;
 636
 637         ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
 638         if (!ctx)
 639                 return -ENOMEM;
 640
 641         ctx->type = AFSVL_ROVOL;
 642         ctx->net = afs_net(fc->net_ns);
 643
 644         /* Default to the workstation cell. */
 645         cell = afs_find_cell(ctx->net, NULL, 0, afs_cell_trace_use_fc);
 646         if (IS_ERR(cell))
 647                 cell = NULL;
 648         ctx->cell = cell;
 649
 650         fc->fs_private = ctx;
 651         fc->ops = &afs_context_ops;
 652         return 0;
 653 }
 654
 655 /*
 656  * Initialise an inode cache slab element prior to any use.  Note that
 657  * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
 658  * inode to another.
 659  */
 660 static void afs_i_init_once(void *_vnode)
 661 {
 662         struct afs_vnode *vnode = _vnode;
 663
 664         memset(vnode, 0, sizeof(*vnode));
 665         inode_init_once(&vnode->netfs.inode);
 666         mutex_init(&vnode->io_lock);
 667         init_rwsem(&vnode->validate_lock);
 668         spin_lock_init(&vnode->wb_lock);
 669         spin_lock_init(&vnode->lock);
 670         INIT_LIST_HEAD(&vnode->wb_keys);
 671         INIT_LIST_HEAD(&vnode->pending_locks);
 672         INIT_LIST_HEAD(&vnode->granted_locks);
 673         INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
 674         INIT_LIST_HEAD(&vnode->cb_mmap_link);
 675         seqlock_init(&vnode->cb_lock);
 676 }
 677
 678 /*
 679  * allocate an AFS inode struct from our slab cache
 680  */
 681 static struct inode *afs_alloc_inode(struct super_block *sb)
 682 {
 683         struct afs_vnode *vnode;
 684
 685         vnode = alloc_inode_sb(sb, afs_inode_cachep, GFP_KERNEL);
 686         if (!vnode)
 687                 return NULL;
 688
 689         atomic_inc(&afs_count_active_inodes);
 690
 691         /* Reset anything that shouldn't leak from one inode to the next. */
 692         memset(&vnode->fid, 0, sizeof(vnode->fid));
 693         memset(&vnode->status, 0, sizeof(vnode->status));
 694         afs_vnode_set_cache(vnode, NULL);
 695
 696         vnode->volume           = NULL;
 697         vnode->lock_key         = NULL;
 698         vnode->permit_cache     = NULL;
 699
 700         vnode->flags            = 1 << AFS_VNODE_UNSET;
 701         vnode->lock_state       = AFS_VNODE_LOCK_NONE;
 702
 703         init_rwsem(&vnode->rmdir_lock);
 704         INIT_WORK(&vnode->cb_work, afs_invalidate_mmap_work);
 705
 706         _leave(" = %p", &vnode->netfs.inode);
 707         return &vnode->netfs.inode;
 708 }
 709
 710 static void afs_free_inode(struct inode *inode)
 711 {
 712         kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
 713 }
 714
 715 /*
 716  * destroy an AFS inode struct
 717  */
 718 static void afs_destroy_inode(struct inode *inode)
 719 {
 720         struct afs_vnode *vnode = AFS_FS_I(inode);
 721
 722         _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
 723
 724         _debug("DESTROY INODE %p", inode);
 725
 726         atomic_dec(&afs_count_active_inodes);
 727 }
 728
 729 static void afs_get_volume_status_success(struct afs_operation *op)
 730 {
 731         struct afs_volume_status *vs = &op->volstatus.vs;
 732         struct kstatfs *buf = op->volstatus.buf;
 733
 734         if (vs->max_quota == 0)
 735                 buf->f_blocks = vs->part_max_blocks;
 736         else
 737                 buf->f_blocks = vs->max_quota;
 738
 739         if (buf->f_blocks > vs->blocks_in_use)
 740                 buf->f_bavail = buf->f_bfree =
 741                         buf->f_blocks - vs->blocks_in_use;
 742 }
 743
 744 static const struct afs_operation_ops afs_get_volume_status_operation = {
 745         .issue_afs_rpc  = afs_fs_get_volume_status,
 746         .issue_yfs_rpc  = yfs_fs_get_volume_status,
 747         .success        = afs_get_volume_status_success,
 748 };
 749
 750 /*
 751  * return information about an AFS volume
 752  */
 753 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
 754 {
 755         struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
 756         struct afs_operation *op;
 757         struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
 758
 759         buf->f_type     = dentry->d_sb->s_magic;
 760         buf->f_bsize    = AFS_BLOCK_SIZE;
 761         buf->f_namelen  = AFSNAMEMAX - 1;
 762
 763         if (as->dyn_root) {
 764                 buf->f_blocks   = 1;
 765                 buf->f_bavail   = 0;
 766                 buf->f_bfree    = 0;
 767                 return 0;
 768         }
 769
 770         op = afs_alloc_operation(NULL, as->volume);
 771         if (IS_ERR(op))
 772                 return PTR_ERR(op);
 773
 774         afs_op_set_vnode(op, 0, vnode);
 775         op->nr_files            = 1;
 776         op->volstatus.buf       = buf;
 777         op->ops                 = &afs_get_volume_status_operation;
 778         return afs_do_sync_operation(op);
 779 }