fs/afs/inode.c

   1 /*
   2  * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
   3  *
   4  * This software may be freely redistributed under the terms of the
   5  * GNU General Public License.
   6  *
   7  * You should have received a copy of the GNU General Public License
   8  * along with this program; if not, write to the Free Software
   9  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  10  *
  11  * Authors: David Woodhouse <dwmw2@infradead.org>
  12  *          David Howells <dhowells@redhat.com>
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/fs.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/sched.h>
  22 #include <linux/mount.h>
  23 #include <linux/namei.h>
  24 #include <linux/iversion.h>
  25 #include "internal.h"
  26 #include "afs_fs.h"
  27
  28 static const struct inode_operations afs_symlink_inode_operations = {
  29         .get_link       = page_get_link,
  30         .listxattr      = afs_listxattr,
  31 };
  32
  33 static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode)
  34 {
  35         static unsigned long once_only;
  36
  37         pr_warn("kAFS: AFS vnode with undefined type %u\n", vnode->status.type);
  38         pr_warn("kAFS: A=%d m=%o s=%llx v=%llx\n",
  39                 vnode->status.abort_code,
  40                 vnode->status.mode,
  41                 vnode->status.size,
  42                 vnode->status.data_version);
  43         pr_warn("kAFS: vnode %llx:%llx:%x\n",
  44                 vnode->fid.vid,
  45                 vnode->fid.vnode,
  46                 vnode->fid.unique);
  47         if (parent_vnode)
  48                 pr_warn("kAFS: dir %llx:%llx:%x\n",
  49                         parent_vnode->fid.vid,
  50                         parent_vnode->fid.vnode,
  51                         parent_vnode->fid.unique);
  52
  53         if (!test_and_set_bit(0, &once_only))
  54                 dump_stack();
  55 }
  56
  57 /*
  58  * Set the file size and block count.  Estimate the number of 512 bytes blocks
  59  * used, rounded up to nearest 1K for consistency with other AFS clients.
  60  */
  61 static void afs_set_i_size(struct afs_vnode *vnode, u64 size)
  62 {
  63         i_size_write(&vnode->vfs_inode, size);
  64         vnode->vfs_inode.i_blocks = ((size + 1023) >> 10) << 1;
  65 }
  66
  67 /*
  68  * Initialise an inode from the vnode status.
  69  */
  70 static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key,
  71                                       struct afs_cb_interest *cbi,
  72                                       struct afs_vnode *parent_vnode,
  73                                       struct afs_status_cb *scb)
  74 {
  75         struct afs_cb_interest *old_cbi = NULL;
  76         struct afs_file_status *status = &scb->status;
  77         struct inode *inode = AFS_VNODE_TO_I(vnode);
  78         struct timespec64 t;
  79
  80         _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
  81                status->type,
  82                status->nlink,
  83                (unsigned long long) status->size,
  84                status->data_version,
  85                status->mode);
  86
  87         write_seqlock(&vnode->cb_lock);
  88
  89         vnode->status = *status;
  90
  91         t = status->mtime_client;
  92         inode->i_ctime = t;
  93         inode->i_mtime = t;
  94         inode->i_atime = t;
  95         inode->i_uid = make_kuid(&init_user_ns, status->owner);
  96         inode->i_gid = make_kgid(&init_user_ns, status->group);
  97         set_nlink(&vnode->vfs_inode, status->nlink);
  98
  99         switch (status->type) {
 100         case AFS_FTYPE_FILE:
 101                 inode->i_mode   = S_IFREG | status->mode;
 102                 inode->i_op     = &afs_file_inode_operations;
 103                 inode->i_fop    = &afs_file_operations;
 104                 inode->i_mapping->a_ops = &afs_fs_aops;
 105                 break;
 106         case AFS_FTYPE_DIR:
 107                 inode->i_mode   = S_IFDIR | status->mode;
 108                 inode->i_op     = &afs_dir_inode_operations;
 109                 inode->i_fop    = &afs_dir_file_operations;
 110                 inode->i_mapping->a_ops = &afs_dir_aops;
 111                 break;
 112         case AFS_FTYPE_SYMLINK:
 113                 /* Symlinks with a mode of 0644 are actually mountpoints. */
 114                 if ((status->mode & 0777) == 0644) {
 115                         inode->i_flags |= S_AUTOMOUNT;
 116
 117                         set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
 118
 119                         inode->i_mode   = S_IFDIR | 0555;
 120                         inode->i_op     = &afs_mntpt_inode_operations;
 121                         inode->i_fop    = &afs_mntpt_file_operations;
 122                         inode->i_mapping->a_ops = &afs_fs_aops;
 123                 } else {
 124                         inode->i_mode   = S_IFLNK | status->mode;
 125                         inode->i_op     = &afs_symlink_inode_operations;
 126                         inode->i_mapping->a_ops = &afs_fs_aops;
 127                 }
 128                 inode_nohighmem(inode);
 129                 break;
 130         default:
 131                 dump_vnode(vnode, parent_vnode);
 132                 write_sequnlock(&vnode->cb_lock);
 133                 return afs_protocol_error(NULL, afs_eproto_file_type);
 134         }
 135
 136         afs_set_i_size(vnode, status->size);
 137
 138         vnode->invalid_before   = status->data_version;
 139         inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
 140
 141         if (!scb->have_cb) {
 142                 /* it's a symlink we just created (the fileserver
 143                  * didn't give us a callback) */
 144                 vnode->cb_expires_at = ktime_get_real_seconds();
 145         } else {
 146                 vnode->cb_expires_at = scb->callback.expires_at;
 147                 old_cbi = rcu_dereference_protected(vnode->cb_interest,
 148                                                     lockdep_is_held(&vnode->cb_lock.lock));
 149                 if (cbi != old_cbi)
 150                         rcu_assign_pointer(vnode->cb_interest, afs_get_cb_interest(cbi));
 151                 else
 152                         old_cbi = NULL;
 153                 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
 154         }
 155
 156         write_sequnlock(&vnode->cb_lock);
 157         afs_put_cb_interest(afs_v2net(vnode), old_cbi);
 158         return 0;
 159 }
 160
 161 /*
 162  * Update the core inode struct from a returned status record.
 163  */
 164 static void afs_apply_status(struct afs_fs_cursor *fc,
 165                              struct afs_vnode *vnode,
 166                              struct afs_status_cb *scb,
 167                              const afs_dataversion_t *expected_version)
 168 {
 169         struct afs_file_status *status = &scb->status;
 170         struct timespec64 t;
 171         umode_t mode;
 172         bool data_changed = false;
 173         bool change_size = false;
 174
 175         BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
 176
 177         if (status->type != vnode->status.type) {
 178                 pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
 179                         vnode->fid.vid,
 180                         vnode->fid.vnode,
 181                         vnode->fid.unique,
 182                         status->type, vnode->status.type);
 183                 afs_protocol_error(NULL, afs_eproto_bad_status);
 184                 return;
 185         }
 186
 187         if (status->nlink != vnode->status.nlink)
 188                 set_nlink(&vnode->vfs_inode, status->nlink);
 189
 190         if (status->owner != vnode->status.owner)
 191                 vnode->vfs_inode.i_uid = make_kuid(&init_user_ns, status->owner);
 192
 193         if (status->group != vnode->status.group)
 194                 vnode->vfs_inode.i_gid = make_kgid(&init_user_ns, status->group);
 195
 196         if (status->mode != vnode->status.mode) {
 197                 mode = vnode->vfs_inode.i_mode;
 198                 mode &= ~S_IALLUGO;
 199                 mode |= status->mode;
 200                 WRITE_ONCE(vnode->vfs_inode.i_mode, mode);
 201         }
 202
 203         t = status->mtime_client;
 204         vnode->vfs_inode.i_ctime = t;
 205         vnode->vfs_inode.i_mtime = t;
 206         vnode->vfs_inode.i_atime = t;
 207
 208         if (vnode->status.data_version != status->data_version)
 209                 data_changed = true;
 210
 211         vnode->status = *status;
 212
 213         if (expected_version &&
 214             *expected_version != status->data_version) {
 215                 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
 216                         pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s\n",
 217                                 vnode->fid.vid, vnode->fid.vnode,
 218                                 (unsigned long long)*expected_version,
 219                                 (unsigned long long)status->data_version,
 220                                 fc->type ? fc->type->name : "???");
 221
 222                 vnode->invalid_before = status->data_version;
 223                 if (vnode->status.type == AFS_FTYPE_DIR) {
 224                         if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
 225                                 afs_stat_v(vnode, n_inval);
 226                 } else {
 227                         set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
 228                 }
 229                 change_size = true;
 230         } else if (vnode->status.type == AFS_FTYPE_DIR) {
 231                 /* Expected directory change is handled elsewhere so
 232                  * that we can locally edit the directory and save on a
 233                  * download.
 234                  */
 235                 if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
 236                         data_changed = false;
 237                 change_size = true;
 238         }
 239
 240         if (data_changed) {
 241                 inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
 242
 243                 /* Only update the size if the data version jumped.  If the
 244                  * file is being modified locally, then we might have our own
 245                  * idea of what the size should be that's not the same as
 246                  * what's on the server.
 247                  */
 248                 if (change_size)
 249                         afs_set_i_size(vnode, status->size);
 250         }
 251 }
 252
 253 /*
 254  * Apply a callback to a vnode.
 255  */
 256 static void afs_apply_callback(struct afs_fs_cursor *fc,
 257                                struct afs_vnode *vnode,
 258                                struct afs_status_cb *scb,
 259                                unsigned int cb_break)
 260 {
 261         struct afs_cb_interest *old;
 262         struct afs_callback *cb = &scb->callback;
 263
 264         if (!afs_cb_is_broken(cb_break, vnode, fc->cbi)) {
 265                 vnode->cb_expires_at    = cb->expires_at;
 266                 old = rcu_dereference_protected(vnode->cb_interest,
 267                                                 lockdep_is_held(&vnode->cb_lock.lock));
 268                 if (old != fc->cbi) {
 269                         rcu_assign_pointer(vnode->cb_interest, afs_get_cb_interest(fc->cbi));
 270                         afs_put_cb_interest(afs_v2net(vnode), old);
 271                 }
 272                 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
 273         }
 274 }
 275
 276 /*
 277  * Apply the received status and callback to an inode all in the same critical
 278  * section to avoid races with afs_validate().
 279  */
 280 void afs_vnode_commit_status(struct afs_fs_cursor *fc,
 281                              struct afs_vnode *vnode,
 282                              unsigned int cb_break,
 283                              const afs_dataversion_t *expected_version,
 284                              struct afs_status_cb *scb)
 285 {
 286         if (fc->ac.error != 0)
 287                 return;
 288
 289         write_seqlock(&vnode->cb_lock);
 290
 291         if (scb->have_error) {
 292                 if (scb->status.abort_code == VNOVNODE) {
 293                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 294                         clear_nlink(&vnode->vfs_inode);
 295                         __afs_break_callback(vnode, afs_cb_break_for_deleted);
 296                 }
 297         } else {
 298                 if (scb->have_status)
 299                         afs_apply_status(fc, vnode, scb, expected_version);
 300                 if (scb->have_cb)
 301                         afs_apply_callback(fc, vnode, scb, cb_break);
 302         }
 303
 304         write_sequnlock(&vnode->cb_lock);
 305
 306         if (fc->ac.error == 0 && scb->have_status)
 307                 afs_cache_permit(vnode, fc->key, cb_break, scb);
 308 }
 309
 310 /*
 311  * Fetch file status from the volume.
 312  */
 313 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
 314                      afs_access_t *_caller_access)
 315 {
 316         struct afs_status_cb *scb;
 317         struct afs_fs_cursor fc;
 318         int ret;
 319
 320         _enter("%s,{%llx:%llu.%u,S=%lx}",
 321                vnode->volume->name,
 322                vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
 323                vnode->flags);
 324
 325         scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
 326         if (!scb)
 327                 return -ENOMEM;
 328
 329         ret = -ERESTARTSYS;
 330         if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
 331                 afs_dataversion_t data_version = vnode->status.data_version;
 332
 333                 while (afs_select_fileserver(&fc)) {
 334                         fc.cb_break = afs_calc_vnode_cb_break(vnode);
 335                         afs_fs_fetch_file_status(&fc, scb, NULL);
 336                 }
 337
 338                 if (fc.error) {
 339                         /* Do nothing. */
 340                 } else if (is_new) {
 341                         ret = afs_inode_init_from_status(vnode, key, fc.cbi,
 342                                                          NULL, scb);
 343                         fc.error = ret;
 344                         if (ret == 0)
 345                                 afs_cache_permit(vnode, key, fc.cb_break, scb);
 346                 } else {
 347                         afs_vnode_commit_status(&fc, vnode, fc.cb_break,
 348                                                 &data_version, scb);
 349                 }
 350                 afs_check_for_remote_deletion(&fc, vnode);
 351                 ret = afs_end_vnode_operation(&fc);
 352         }
 353
 354         if (ret == 0 && _caller_access)
 355                 *_caller_access = scb->status.caller_access;
 356         kfree(scb);
 357         _leave(" = %d", ret);
 358         return ret;
 359 }
 360
 361 /*
 362  * iget5() comparator
 363  */
 364 int afs_iget5_test(struct inode *inode, void *opaque)
 365 {
 366         struct afs_iget_data *iget_data = opaque;
 367         struct afs_vnode *vnode = AFS_FS_I(inode);
 368
 369         return memcmp(&vnode->fid, &iget_data->fid, sizeof(iget_data->fid)) == 0;
 370 }
 371
 372 /*
 373  * iget5() comparator for inode created by autocell operations
 374  *
 375  * These pseudo inodes don't match anything.
 376  */
 377 static int afs_iget5_pseudo_dir_test(struct inode *inode, void *opaque)
 378 {
 379         return 0;
 380 }
 381
 382 /*
 383  * iget5() inode initialiser
 384  */
 385 static int afs_iget5_set(struct inode *inode, void *opaque)
 386 {
 387         struct afs_iget_data *iget_data = opaque;
 388         struct afs_vnode *vnode = AFS_FS_I(inode);
 389
 390         vnode->fid              = iget_data->fid;
 391         vnode->volume           = iget_data->volume;
 392         vnode->cb_v_break       = iget_data->cb_v_break;
 393         vnode->cb_s_break       = iget_data->cb_s_break;
 394
 395         /* YFS supports 96-bit vnode IDs, but Linux only supports
 396          * 64-bit inode numbers.
 397          */
 398         inode->i_ino            = iget_data->fid.vnode;
 399         inode->i_generation     = iget_data->fid.unique;
 400         return 0;
 401 }
 402
 403 /*
 404  * Create an inode for a dynamic root directory or an autocell dynamic
 405  * automount dir.
 406  */
 407 struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
 408 {
 409         struct afs_super_info *as;
 410         struct afs_vnode *vnode;
 411         struct inode *inode;
 412         static atomic_t afs_autocell_ino;
 413
 414         struct afs_iget_data iget_data = {
 415                 .cb_v_break = 0,
 416                 .cb_s_break = 0,
 417         };
 418
 419         _enter("");
 420
 421         as = sb->s_fs_info;
 422         if (as->volume) {
 423                 iget_data.volume = as->volume;
 424                 iget_data.fid.vid = as->volume->vid;
 425         }
 426         if (root) {
 427                 iget_data.fid.vnode = 1;
 428                 iget_data.fid.unique = 1;
 429         } else {
 430                 iget_data.fid.vnode = atomic_inc_return(&afs_autocell_ino);
 431                 iget_data.fid.unique = 0;
 432         }
 433
 434         inode = iget5_locked(sb, iget_data.fid.vnode,
 435                              afs_iget5_pseudo_dir_test, afs_iget5_set,
 436                              &iget_data);
 437         if (!inode) {
 438                 _leave(" = -ENOMEM");
 439                 return ERR_PTR(-ENOMEM);
 440         }
 441
 442         _debug("GOT INODE %p { ino=%lu, vl=%llx, vn=%llx, u=%x }",
 443                inode, inode->i_ino, iget_data.fid.vid, iget_data.fid.vnode,
 444                iget_data.fid.unique);
 445
 446         vnode = AFS_FS_I(inode);
 447
 448         /* there shouldn't be an existing inode */
 449         BUG_ON(!(inode->i_state & I_NEW));
 450
 451         inode->i_size           = 0;
 452         inode->i_mode           = S_IFDIR | S_IRUGO | S_IXUGO;
 453         if (root) {
 454                 inode->i_op     = &afs_dynroot_inode_operations;
 455                 inode->i_fop    = &simple_dir_operations;
 456         } else {
 457                 inode->i_op     = &afs_autocell_inode_operations;
 458         }
 459         set_nlink(inode, 2);
 460         inode->i_uid            = GLOBAL_ROOT_UID;
 461         inode->i_gid            = GLOBAL_ROOT_GID;
 462         inode->i_ctime = inode->i_atime = inode->i_mtime = current_time(inode);
 463         inode->i_blocks         = 0;
 464         inode_set_iversion_raw(inode, 0);
 465         inode->i_generation     = 0;
 466
 467         set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
 468         if (!root) {
 469                 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
 470                 inode->i_flags |= S_AUTOMOUNT;
 471         }
 472
 473         inode->i_flags |= S_NOATIME;
 474         unlock_new_inode(inode);
 475         _leave(" = %p", inode);
 476         return inode;
 477 }
 478
 479 /*
 480  * Get a cache cookie for an inode.
 481  */
 482 static void afs_get_inode_cache(struct afs_vnode *vnode)
 483 {
 484 #ifdef CONFIG_AFS_FSCACHE
 485         struct {
 486                 u32 vnode_id;
 487                 u32 unique;
 488                 u32 vnode_id_ext[2];    /* Allow for a 96-bit key */
 489         } __packed key;
 490         struct afs_vnode_cache_aux aux;
 491
 492         if (vnode->status.type == AFS_FTYPE_DIR) {
 493                 vnode->cache = NULL;
 494                 return;
 495         }
 496
 497         key.vnode_id            = vnode->fid.vnode;
 498         key.unique              = vnode->fid.unique;
 499         key.vnode_id_ext[0]     = vnode->fid.vnode >> 32;
 500         key.vnode_id_ext[1]     = vnode->fid.vnode_hi;
 501         aux.data_version        = vnode->status.data_version;
 502
 503         vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
 504                                               &afs_vnode_cache_index_def,
 505                                               &key, sizeof(key),
 506                                               &aux, sizeof(aux),
 507                                               vnode, vnode->status.size, true);
 508 #endif
 509 }
 510
 511 /*
 512  * inode retrieval
 513  */
 514 struct inode *afs_iget(struct super_block *sb, struct key *key,
 515                        struct afs_iget_data *iget_data,
 516                        struct afs_status_cb *scb,
 517                        struct afs_cb_interest *cbi,
 518                        struct afs_vnode *parent_vnode)
 519 {
 520         struct afs_super_info *as;
 521         struct afs_vnode *vnode;
 522         struct afs_fid *fid = &iget_data->fid;
 523         struct inode *inode;
 524         int ret;
 525
 526         _enter(",{%llx:%llu.%u},,", fid->vid, fid->vnode, fid->unique);
 527
 528         as = sb->s_fs_info;
 529         iget_data->volume = as->volume;
 530
 531         inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
 532                              iget_data);
 533         if (!inode) {
 534                 _leave(" = -ENOMEM");
 535                 return ERR_PTR(-ENOMEM);
 536         }
 537
 538         _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
 539                inode, fid->vid, fid->vnode, fid->unique);
 540
 541         vnode = AFS_FS_I(inode);
 542
 543         /* deal with an existing inode */
 544         if (!(inode->i_state & I_NEW)) {
 545                 _leave(" = %p", inode);
 546                 return inode;
 547         }
 548
 549         if (!scb) {
 550                 /* it's a remotely extant inode */
 551                 ret = afs_fetch_status(vnode, key, true, NULL);
 552                 if (ret < 0)
 553                         goto bad_inode;
 554         } else {
 555                 ret = afs_inode_init_from_status(vnode, key, cbi, parent_vnode,
 556                                                  scb);
 557                 if (ret < 0)
 558                         goto bad_inode;
 559         }
 560
 561         afs_get_inode_cache(vnode);
 562
 563         /* success */
 564         clear_bit(AFS_VNODE_UNSET, &vnode->flags);
 565         inode->i_flags |= S_NOATIME;
 566         unlock_new_inode(inode);
 567         _leave(" = %p", inode);
 568         return inode;
 569
 570         /* failure */
 571 bad_inode:
 572         iget_failed(inode);
 573         _leave(" = %d [bad]", ret);
 574         return ERR_PTR(ret);
 575 }
 576
 577 /*
 578  * mark the data attached to an inode as obsolete due to a write on the server
 579  * - might also want to ditch all the outstanding writes and dirty pages
 580  */
 581 void afs_zap_data(struct afs_vnode *vnode)
 582 {
 583         _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
 584
 585 #ifdef CONFIG_AFS_FSCACHE
 586         fscache_invalidate(vnode->cache);
 587 #endif
 588
 589         /* nuke all the non-dirty pages that aren't locked, mapped or being
 590          * written back in a regular file and completely discard the pages in a
 591          * directory or symlink */
 592         if (S_ISREG(vnode->vfs_inode.i_mode))
 593                 invalidate_remote_inode(&vnode->vfs_inode);
 594         else
 595                 invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
 596 }
 597
 598 /*
 599  * Check the validity of a vnode/inode.
 600  */
 601 bool afs_check_validity(struct afs_vnode *vnode)
 602 {
 603         struct afs_cb_interest *cbi;
 604         struct afs_server *server;
 605         struct afs_volume *volume = vnode->volume;
 606         enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
 607         time64_t now = ktime_get_real_seconds();
 608         bool valid;
 609         unsigned int cb_break, cb_s_break, cb_v_break;
 610         int seq = 0;
 611
 612         do {
 613                 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
 614                 cb_v_break = READ_ONCE(volume->cb_v_break);
 615                 cb_break = vnode->cb_break;
 616
 617                 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
 618                         cbi = rcu_dereference(vnode->cb_interest);
 619                         server = rcu_dereference(cbi->server);
 620                         cb_s_break = READ_ONCE(server->cb_s_break);
 621
 622                         if (vnode->cb_s_break != cb_s_break ||
 623                             vnode->cb_v_break != cb_v_break) {
 624                                 vnode->cb_s_break = cb_s_break;
 625                                 vnode->cb_v_break = cb_v_break;
 626                                 need_clear = afs_cb_break_for_vsbreak;
 627                                 valid = false;
 628                         } else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
 629                                 need_clear = afs_cb_break_for_zap;
 630                                 valid = false;
 631                         } else if (vnode->cb_expires_at - 10 <= now) {
 632                                 need_clear = afs_cb_break_for_lapsed;
 633                                 valid = false;
 634                         } else {
 635                                 valid = true;
 636                         }
 637                 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 638                         valid = true;
 639                 } else {
 640                         vnode->cb_v_break = cb_v_break;
 641                         valid = false;
 642                 }
 643
 644         } while (need_seqretry(&vnode->cb_lock, seq));
 645
 646         done_seqretry(&vnode->cb_lock, seq);
 647
 648         if (need_clear != afs_cb_break_no_break) {
 649                 write_seqlock(&vnode->cb_lock);
 650                 if (cb_break == vnode->cb_break)
 651                         __afs_break_callback(vnode, need_clear);
 652                 else
 653                         trace_afs_cb_miss(&vnode->fid, need_clear);
 654                 write_sequnlock(&vnode->cb_lock);
 655                 valid = false;
 656         }
 657
 658         return valid;
 659 }
 660
 661 /*
 662  * validate a vnode/inode
 663  * - there are several things we need to check
 664  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
 665  *     symlink)
 666  *   - parent dir metadata changed (security changes)
 667  *   - dentry data changed (write, truncate)
 668  *   - dentry metadata changed (security changes)
 669  */
 670 int afs_validate(struct afs_vnode *vnode, struct key *key)
 671 {
 672         bool valid;
 673         int ret;
 674
 675         _enter("{v={%llx:%llu} fl=%lx},%x",
 676                vnode->fid.vid, vnode->fid.vnode, vnode->flags,
 677                key_serial(key));
 678
 679         rcu_read_lock();
 680         valid = afs_check_validity(vnode);
 681         rcu_read_unlock();
 682
 683         if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 684                 clear_nlink(&vnode->vfs_inode);
 685
 686         if (valid)
 687                 goto valid;
 688
 689         down_write(&vnode->validate_lock);
 690
 691         /* if the promise has expired, we need to check the server again to get
 692          * a new promise - note that if the (parent) directory's metadata was
 693          * changed then the security may be different and we may no longer have
 694          * access */
 695         if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
 696                 _debug("not promised");
 697                 ret = afs_fetch_status(vnode, key, false, NULL);
 698                 if (ret < 0) {
 699                         if (ret == -ENOENT) {
 700                                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 701                                 ret = -ESTALE;
 702                         }
 703                         goto error_unlock;
 704                 }
 705                 _debug("new promise [fl=%lx]", vnode->flags);
 706         }
 707
 708         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 709                 _debug("file already deleted");
 710                 ret = -ESTALE;
 711                 goto error_unlock;
 712         }
 713
 714         /* if the vnode's data version number changed then its contents are
 715          * different */
 716         if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
 717                 afs_zap_data(vnode);
 718         up_write(&vnode->validate_lock);
 719 valid:
 720         _leave(" = 0");
 721         return 0;
 722
 723 error_unlock:
 724         up_write(&vnode->validate_lock);
 725         _leave(" = %d", ret);
 726         return ret;
 727 }
 728
 729 /*
 730  * read the attributes of an inode
 731  */
 732 int afs_getattr(const struct path *path, struct kstat *stat,
 733                 u32 request_mask, unsigned int query_flags)
 734 {
 735         struct inode *inode = d_inode(path->dentry);
 736         struct afs_vnode *vnode = AFS_FS_I(inode);
 737         int seq = 0;
 738
 739         _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
 740
 741         do {
 742                 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
 743                 generic_fillattr(inode, stat);
 744         } while (need_seqretry(&vnode->cb_lock, seq));
 745
 746         done_seqretry(&vnode->cb_lock, seq);
 747         return 0;
 748 }
 749
 750 /*
 751  * discard an AFS inode
 752  */
 753 int afs_drop_inode(struct inode *inode)
 754 {
 755         _enter("");
 756
 757         if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
 758                 return generic_delete_inode(inode);
 759         else
 760                 return generic_drop_inode(inode);
 761 }
 762
 763 /*
 764  * clear an AFS inode
 765  */
 766 void afs_evict_inode(struct inode *inode)
 767 {
 768         struct afs_cb_interest *cbi;
 769         struct afs_vnode *vnode;
 770
 771         vnode = AFS_FS_I(inode);
 772
 773         _enter("{%llx:%llu.%d}",
 774                vnode->fid.vid,
 775                vnode->fid.vnode,
 776                vnode->fid.unique);
 777
 778         _debug("CLEAR INODE %p", inode);
 779
 780         ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
 781
 782         truncate_inode_pages_final(&inode->i_data);
 783         clear_inode(inode);
 784
 785         write_seqlock(&vnode->cb_lock);
 786         cbi = rcu_dereference_protected(vnode->cb_interest,
 787                                         lockdep_is_held(&vnode->cb_lock.lock));
 788         if (cbi) {
 789                 afs_put_cb_interest(afs_i2net(inode), cbi);
 790                 rcu_assign_pointer(vnode->cb_interest, NULL);
 791         }
 792         write_sequnlock(&vnode->cb_lock);
 793
 794         while (!list_empty(&vnode->wb_keys)) {
 795                 struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
 796                                                     struct afs_wb_key, vnode_link);
 797                 list_del(&wbk->vnode_link);
 798                 afs_put_wb_key(wbk);
 799         }
 800
 801 #ifdef CONFIG_AFS_FSCACHE
 802         {
 803                 struct afs_vnode_cache_aux aux;
 804
 805                 aux.data_version = vnode->status.data_version;
 806                 fscache_relinquish_cookie(vnode->cache, &aux,
 807                                           test_bit(AFS_VNODE_DELETED, &vnode->flags));
 808                 vnode->cache = NULL;
 809         }
 810 #endif
 811
 812         afs_prune_wb_keys(vnode);
 813         afs_put_permits(rcu_access_pointer(vnode->permit_cache));
 814         key_put(vnode->silly_key);
 815         vnode->silly_key = NULL;
 816         key_put(vnode->lock_key);
 817         vnode->lock_key = NULL;
 818         _leave("");
 819 }
 820
 821 /*
 822  * set the attributes of an inode
 823  */
 824 int afs_setattr(struct dentry *dentry, struct iattr *attr)
 825 {
 826         struct afs_fs_cursor fc;
 827         struct afs_status_cb *scb;
 828         struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
 829         struct key *key;
 830         int ret = -ENOMEM;
 831
 832         _enter("{%llx:%llu},{n=%pd},%x",
 833                vnode->fid.vid, vnode->fid.vnode, dentry,
 834                attr->ia_valid);
 835
 836         if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
 837                                 ATTR_MTIME))) {
 838                 _leave(" = 0 [unsupported]");
 839                 return 0;
 840         }
 841
 842         scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
 843         if (!scb)
 844                 goto error;
 845
 846         /* flush any dirty data outstanding on a regular file */
 847         if (S_ISREG(vnode->vfs_inode.i_mode))
 848                 filemap_write_and_wait(vnode->vfs_inode.i_mapping);
 849
 850         if (attr->ia_valid & ATTR_FILE) {
 851                 key = afs_file_key(attr->ia_file);
 852         } else {
 853                 key = afs_request_key(vnode->volume->cell);
 854                 if (IS_ERR(key)) {
 855                         ret = PTR_ERR(key);
 856                         goto error_scb;
 857                 }
 858         }
 859
 860         ret = -ERESTARTSYS;
 861         if (afs_begin_vnode_operation(&fc, vnode, key, false)) {
 862                 afs_dataversion_t data_version = vnode->status.data_version;
 863
 864                 if (attr->ia_valid & ATTR_SIZE)
 865                         data_version++;
 866
 867                 while (afs_select_fileserver(&fc)) {
 868                         fc.cb_break = afs_calc_vnode_cb_break(vnode);
 869                         afs_fs_setattr(&fc, attr, scb);
 870                 }
 871
 872                 afs_check_for_remote_deletion(&fc, vnode);
 873                 afs_vnode_commit_status(&fc, vnode, fc.cb_break,
 874                                         &data_version, scb);
 875                 ret = afs_end_vnode_operation(&fc);
 876         }
 877
 878         if (!(attr->ia_valid & ATTR_FILE))
 879                 key_put(key);
 880
 881 error_scb:
 882         kfree(scb);
 883 error:
 884         _leave(" = %d", ret);
 885         return ret;
 886 }