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