fs/afs/inode.c

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

DEFINITIONS
