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