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 /* 33 * map the AFS file status to the inode member variables 34 */ 35 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key) 36 { 37 struct inode *inode = AFS_VNODE_TO_I(vnode); 38 bool changed; 39 40 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", 41 vnode->status.type, 42 vnode->status.nlink, 43 (unsigned long long) vnode->status.size, 44 vnode->status.data_version, 45 vnode->status.mode); 46 47 read_seqlock_excl(&vnode->cb_lock); 48 49 switch (vnode->status.type) { 50 case AFS_FTYPE_FILE: 51 inode->i_mode = S_IFREG | vnode->status.mode; 52 inode->i_op = &afs_file_inode_operations; 53 inode->i_fop = &afs_file_operations; 54 break; 55 case AFS_FTYPE_DIR: 56 inode->i_mode = S_IFDIR | vnode->status.mode; 57 inode->i_op = &afs_dir_inode_operations; 58 inode->i_fop = &afs_dir_file_operations; 59 break; 60 case AFS_FTYPE_SYMLINK: 61 /* Symlinks with a mode of 0644 are actually mountpoints. */ 62 if ((vnode->status.mode & 0777) == 0644) { 63 inode->i_flags |= S_AUTOMOUNT; 64 65 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags); 66 67 inode->i_mode = S_IFDIR | 0555; 68 inode->i_op = &afs_mntpt_inode_operations; 69 inode->i_fop = &afs_mntpt_file_operations; 70 } else { 71 inode->i_mode = S_IFLNK | vnode->status.mode; 72 inode->i_op = &afs_symlink_inode_operations; 73 } 74 inode_nohighmem(inode); 75 break; 76 default: 77 printk("kAFS: AFS vnode with undefined type\n"); 78 read_sequnlock_excl(&vnode->cb_lock); 79 return -EBADMSG; 80 } 81 82 changed = (vnode->status.size != inode->i_size); 83 84 set_nlink(inode, vnode->status.nlink); 85 inode->i_uid = vnode->status.owner; 86 inode->i_gid = vnode->status.group; 87 inode->i_size = vnode->status.size; 88 inode->i_ctime.tv_sec = vnode->status.mtime_client; 89 inode->i_ctime.tv_nsec = 0; 90 inode->i_atime = inode->i_mtime = inode->i_ctime; 91 inode->i_blocks = 0; 92 inode->i_generation = vnode->fid.unique; 93 inode_set_iversion_raw(inode, vnode->status.data_version); 94 inode->i_mapping->a_ops = &afs_fs_aops; 95 96 read_sequnlock_excl(&vnode->cb_lock); 97 98 #ifdef CONFIG_AFS_FSCACHE 99 if (changed) 100 fscache_attr_changed(vnode->cache); 101 #endif 102 return 0; 103 } 104 105 /* 106 * Fetch file status from the volume. 107 */ 108 int afs_fetch_status(struct afs_vnode *vnode, struct key *key) 109 { 110 struct afs_fs_cursor fc; 111 int ret; 112 113 _enter("%s,{%x:%u.%u,S=%lx}", 114 vnode->volume->name, 115 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique, 116 vnode->flags); 117 118 ret = -ERESTARTSYS; 119 if (afs_begin_vnode_operation(&fc, vnode, key)) { 120 while (afs_select_fileserver(&fc)) { 121 fc.cb_break = vnode->cb_break + vnode->cb_s_break; 122 afs_fs_fetch_file_status(&fc, NULL); 123 } 124 125 afs_check_for_remote_deletion(&fc, fc.vnode); 126 afs_vnode_commit_status(&fc, vnode, fc.cb_break); 127 ret = afs_end_vnode_operation(&fc); 128 } 129 130 _leave(" = %d", ret); 131 return ret; 132 } 133 134 /* 135 * iget5() comparator 136 */ 137 int afs_iget5_test(struct inode *inode, void *opaque) 138 { 139 struct afs_iget_data *data = opaque; 140 141 return inode->i_ino == data->fid.vnode && 142 inode->i_generation == data->fid.unique; 143 } 144 145 /* 146 * iget5() comparator for inode created by autocell operations 147 * 148 * These pseudo inodes don't match anything. 149 */ 150 static int afs_iget5_pseudo_dir_test(struct inode *inode, void *opaque) 151 { 152 return 0; 153 } 154 155 /* 156 * iget5() inode initialiser 157 */ 158 static int afs_iget5_set(struct inode *inode, void *opaque) 159 { 160 struct afs_iget_data *data = opaque; 161 struct afs_vnode *vnode = AFS_FS_I(inode); 162 163 inode->i_ino = data->fid.vnode; 164 inode->i_generation = data->fid.unique; 165 vnode->fid = data->fid; 166 vnode->volume = data->volume; 167 168 return 0; 169 } 170 171 /* 172 * Create an inode for a dynamic root directory or an autocell dynamic 173 * automount dir. 174 */ 175 struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root) 176 { 177 struct afs_iget_data data; 178 struct afs_super_info *as; 179 struct afs_vnode *vnode; 180 struct inode *inode; 181 static atomic_t afs_autocell_ino; 182 183 _enter(""); 184 185 as = sb->s_fs_info; 186 if (as->volume) { 187 data.volume = as->volume; 188 data.fid.vid = as->volume->vid; 189 } 190 if (root) { 191 data.fid.vnode = 1; 192 data.fid.unique = 1; 193 } else { 194 data.fid.vnode = atomic_inc_return(&afs_autocell_ino); 195 data.fid.unique = 0; 196 } 197 198 inode = iget5_locked(sb, data.fid.vnode, 199 afs_iget5_pseudo_dir_test, afs_iget5_set, 200 &data); 201 if (!inode) { 202 _leave(" = -ENOMEM"); 203 return ERR_PTR(-ENOMEM); 204 } 205 206 _debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }", 207 inode, inode->i_ino, data.fid.vid, data.fid.vnode, 208 data.fid.unique); 209 210 vnode = AFS_FS_I(inode); 211 212 /* there shouldn't be an existing inode */ 213 BUG_ON(!(inode->i_state & I_NEW)); 214 215 inode->i_size = 0; 216 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; 217 if (root) { 218 inode->i_op = &afs_dynroot_inode_operations; 219 inode->i_fop = &afs_dynroot_file_operations; 220 } else { 221 inode->i_op = &afs_autocell_inode_operations; 222 } 223 set_nlink(inode, 2); 224 inode->i_uid = GLOBAL_ROOT_UID; 225 inode->i_gid = GLOBAL_ROOT_GID; 226 inode->i_ctime.tv_sec = get_seconds(); 227 inode->i_ctime.tv_nsec = 0; 228 inode->i_atime = inode->i_mtime = inode->i_ctime; 229 inode->i_blocks = 0; 230 inode_set_iversion_raw(inode, 0); 231 inode->i_generation = 0; 232 233 set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags); 234 if (!root) { 235 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags); 236 inode->i_flags |= S_AUTOMOUNT; 237 } 238 239 inode->i_flags |= S_NOATIME; 240 unlock_new_inode(inode); 241 _leave(" = %p", inode); 242 return inode; 243 } 244 245 /* 246 * Get a cache cookie for an inode. 247 */ 248 static void afs_get_inode_cache(struct afs_vnode *vnode) 249 { 250 #ifdef CONFIG_AFS_FSCACHE 251 struct { 252 u32 vnode_id; 253 u32 unique; 254 u32 vnode_id_ext[2]; /* Allow for a 96-bit key */ 255 } __packed key; 256 struct afs_vnode_cache_aux aux; 257 258 key.vnode_id = vnode->fid.vnode; 259 key.unique = vnode->fid.unique; 260 key.vnode_id_ext[0] = 0; 261 key.vnode_id_ext[1] = 0; 262 aux.data_version = vnode->status.data_version; 263 264 vnode->cache = fscache_acquire_cookie(vnode->volume->cache, 265 &afs_vnode_cache_index_def, 266 &key, sizeof(key), 267 &aux, sizeof(aux), 268 vnode, vnode->status.size, true); 269 #endif 270 } 271 272 /* 273 * inode retrieval 274 */ 275 struct inode *afs_iget(struct super_block *sb, struct key *key, 276 struct afs_fid *fid, struct afs_file_status *status, 277 struct afs_callback *cb, struct afs_cb_interest *cbi) 278 { 279 struct afs_iget_data data = { .fid = *fid }; 280 struct afs_super_info *as; 281 struct afs_vnode *vnode; 282 struct inode *inode; 283 int ret; 284 285 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique); 286 287 as = sb->s_fs_info; 288 data.volume = as->volume; 289 290 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, 291 &data); 292 if (!inode) { 293 _leave(" = -ENOMEM"); 294 return ERR_PTR(-ENOMEM); 295 } 296 297 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }", 298 inode, fid->vid, fid->vnode, fid->unique); 299 300 vnode = AFS_FS_I(inode); 301 302 /* deal with an existing inode */ 303 if (!(inode->i_state & I_NEW)) { 304 _leave(" = %p", inode); 305 return inode; 306 } 307 308 if (!status) { 309 /* it's a remotely extant inode */ 310 ret = afs_fetch_status(vnode, key); 311 if (ret < 0) 312 goto bad_inode; 313 } else { 314 /* it's an inode we just created */ 315 memcpy(&vnode->status, status, sizeof(vnode->status)); 316 317 if (!cb) { 318 /* it's a symlink we just created (the fileserver 319 * didn't give us a callback) */ 320 vnode->cb_version = 0; 321 vnode->cb_type = 0; 322 vnode->cb_expires_at = 0; 323 } else { 324 vnode->cb_version = cb->version; 325 vnode->cb_type = cb->type; 326 vnode->cb_expires_at = cb->expiry; 327 vnode->cb_interest = afs_get_cb_interest(cbi); 328 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); 329 } 330 331 vnode->cb_expires_at += ktime_get_real_seconds(); 332 } 333 334 /* set up caching before mapping the status, as map-status reads the 335 * first page of symlinks to see if they're really mountpoints */ 336 inode->i_size = vnode->status.size; 337 afs_get_inode_cache(vnode); 338 339 ret = afs_inode_map_status(vnode, key); 340 if (ret < 0) 341 goto bad_inode; 342 343 /* success */ 344 clear_bit(AFS_VNODE_UNSET, &vnode->flags); 345 inode->i_flags |= S_NOATIME; 346 unlock_new_inode(inode); 347 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); 348 return inode; 349 350 /* failure */ 351 bad_inode: 352 #ifdef CONFIG_AFS_FSCACHE 353 fscache_relinquish_cookie(vnode->cache, NULL, ret == -ENOENT); 354 vnode->cache = NULL; 355 #endif 356 iget_failed(inode); 357 _leave(" = %d [bad]", ret); 358 return ERR_PTR(ret); 359 } 360 361 /* 362 * mark the data attached to an inode as obsolete due to a write on the server 363 * - might also want to ditch all the outstanding writes and dirty pages 364 */ 365 void afs_zap_data(struct afs_vnode *vnode) 366 { 367 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); 368 369 #ifdef CONFIG_AFS_FSCACHE 370 fscache_invalidate(vnode->cache); 371 #endif 372 373 /* nuke all the non-dirty pages that aren't locked, mapped or being 374 * written back in a regular file and completely discard the pages in a 375 * directory or symlink */ 376 if (S_ISREG(vnode->vfs_inode.i_mode)) 377 invalidate_remote_inode(&vnode->vfs_inode); 378 else 379 invalidate_inode_pages2(vnode->vfs_inode.i_mapping); 380 } 381 382 /* 383 * validate a vnode/inode 384 * - there are several things we need to check 385 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 386 * symlink) 387 * - parent dir metadata changed (security changes) 388 * - dentry data changed (write, truncate) 389 * - dentry metadata changed (security changes) 390 */ 391 int afs_validate(struct afs_vnode *vnode, struct key *key) 392 { 393 time64_t now = ktime_get_real_seconds(); 394 bool valid = false; 395 int ret; 396 397 _enter("{v={%x:%u} fl=%lx},%x", 398 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 399 key_serial(key)); 400 401 /* Quickly check the callback state. Ideally, we'd use read_seqbegin 402 * here, but we have no way to pass the net namespace to the RCU 403 * cleanup for the server record. 404 */ 405 read_seqlock_excl(&vnode->cb_lock); 406 407 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { 408 if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) { 409 vnode->cb_s_break = vnode->cb_interest->server->cb_s_break; 410 } else if (!test_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags) && 411 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) && 412 vnode->cb_expires_at - 10 > now) { 413 valid = true; 414 } 415 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 416 valid = true; 417 } 418 419 read_sequnlock_excl(&vnode->cb_lock); 420 421 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 422 clear_nlink(&vnode->vfs_inode); 423 424 if (valid) 425 goto valid; 426 427 mutex_lock(&vnode->validate_lock); 428 429 /* if the promise has expired, we need to check the server again to get 430 * a new promise - note that if the (parent) directory's metadata was 431 * changed then the security may be different and we may no longer have 432 * access */ 433 if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { 434 _debug("not promised"); 435 ret = afs_fetch_status(vnode, key); 436 if (ret < 0) { 437 if (ret == -ENOENT) { 438 set_bit(AFS_VNODE_DELETED, &vnode->flags); 439 ret = -ESTALE; 440 } 441 goto error_unlock; 442 } 443 _debug("new promise [fl=%lx]", vnode->flags); 444 } 445 446 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 447 _debug("file already deleted"); 448 ret = -ESTALE; 449 goto error_unlock; 450 } 451 452 /* if the vnode's data version number changed then its contents are 453 * different */ 454 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) 455 afs_zap_data(vnode); 456 457 clear_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags); 458 mutex_unlock(&vnode->validate_lock); 459 valid: 460 _leave(" = 0"); 461 return 0; 462 463 error_unlock: 464 mutex_unlock(&vnode->validate_lock); 465 _leave(" = %d", ret); 466 return ret; 467 } 468 469 /* 470 * read the attributes of an inode 471 */ 472 int afs_getattr(const struct path *path, struct kstat *stat, 473 u32 request_mask, unsigned int query_flags) 474 { 475 struct inode *inode = d_inode(path->dentry); 476 struct afs_vnode *vnode = AFS_FS_I(inode); 477 int seq = 0; 478 479 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation); 480 481 do { 482 read_seqbegin_or_lock(&vnode->cb_lock, &seq); 483 generic_fillattr(inode, stat); 484 } while (need_seqretry(&vnode->cb_lock, seq)); 485 486 done_seqretry(&vnode->cb_lock, seq); 487 return 0; 488 } 489 490 /* 491 * discard an AFS inode 492 */ 493 int afs_drop_inode(struct inode *inode) 494 { 495 _enter(""); 496 497 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags)) 498 return generic_delete_inode(inode); 499 else 500 return generic_drop_inode(inode); 501 } 502 503 /* 504 * clear an AFS inode 505 */ 506 void afs_evict_inode(struct inode *inode) 507 { 508 struct afs_vnode *vnode; 509 510 vnode = AFS_FS_I(inode); 511 512 _enter("{%x:%u.%d}", 513 vnode->fid.vid, 514 vnode->fid.vnode, 515 vnode->fid.unique); 516 517 _debug("CLEAR INODE %p", inode); 518 519 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 520 521 truncate_inode_pages_final(&inode->i_data); 522 clear_inode(inode); 523 524 if (vnode->cb_interest) { 525 afs_put_cb_interest(afs_i2net(inode), vnode->cb_interest); 526 vnode->cb_interest = NULL; 527 } 528 529 while (!list_empty(&vnode->wb_keys)) { 530 struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next, 531 struct afs_wb_key, vnode_link); 532 list_del(&wbk->vnode_link); 533 afs_put_wb_key(wbk); 534 } 535 536 #ifdef CONFIG_AFS_FSCACHE 537 { 538 struct afs_vnode_cache_aux aux; 539 540 aux.data_version = vnode->status.data_version; 541 fscache_relinquish_cookie(vnode->cache, &aux, 542 test_bit(AFS_VNODE_DELETED, &vnode->flags)); 543 vnode->cache = NULL; 544 } 545 #endif 546 547 afs_put_permits(vnode->permit_cache); 548 _leave(""); 549 } 550 551 /* 552 * set the attributes of an inode 553 */ 554 int afs_setattr(struct dentry *dentry, struct iattr *attr) 555 { 556 struct afs_fs_cursor fc; 557 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); 558 struct key *key; 559 int ret; 560 561 _enter("{%x:%u},{n=%pd},%x", 562 vnode->fid.vid, vnode->fid.vnode, dentry, 563 attr->ia_valid); 564 565 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | 566 ATTR_MTIME))) { 567 _leave(" = 0 [unsupported]"); 568 return 0; 569 } 570 571 /* flush any dirty data outstanding on a regular file */ 572 if (S_ISREG(vnode->vfs_inode.i_mode)) 573 filemap_write_and_wait(vnode->vfs_inode.i_mapping); 574 575 if (attr->ia_valid & ATTR_FILE) { 576 key = afs_file_key(attr->ia_file); 577 } else { 578 key = afs_request_key(vnode->volume->cell); 579 if (IS_ERR(key)) { 580 ret = PTR_ERR(key); 581 goto error; 582 } 583 } 584 585 ret = -ERESTARTSYS; 586 if (afs_begin_vnode_operation(&fc, vnode, key)) { 587 while (afs_select_fileserver(&fc)) { 588 fc.cb_break = vnode->cb_break + vnode->cb_s_break; 589 afs_fs_setattr(&fc, attr); 590 } 591 592 afs_check_for_remote_deletion(&fc, fc.vnode); 593 afs_vnode_commit_status(&fc, vnode, fc.cb_break); 594 ret = afs_end_vnode_operation(&fc); 595 } 596 597 if (!(attr->ia_valid & ATTR_FILE)) 598 key_put(key); 599 600 error: 601 _leave(" = %d", ret); 602 return ret; 603 } 604