1 /* netfs cookie management 2 * 3 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * See Documentation/filesystems/caching/netfs-api.txt for more information on 12 * the netfs API. 13 */ 14 15 #define FSCACHE_DEBUG_LEVEL COOKIE 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include "internal.h" 19 20 struct kmem_cache *fscache_cookie_jar; 21 22 static atomic_t fscache_object_debug_id = ATOMIC_INIT(0); 23 24 static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie); 25 static int fscache_alloc_object(struct fscache_cache *cache, 26 struct fscache_cookie *cookie); 27 static int fscache_attach_object(struct fscache_cookie *cookie, 28 struct fscache_object *object); 29 30 /* 31 * initialise an cookie jar slab element prior to any use 32 */ 33 void fscache_cookie_init_once(void *_cookie) 34 { 35 struct fscache_cookie *cookie = _cookie; 36 37 memset(cookie, 0, sizeof(*cookie)); 38 spin_lock_init(&cookie->lock); 39 spin_lock_init(&cookie->stores_lock); 40 INIT_HLIST_HEAD(&cookie->backing_objects); 41 } 42 43 /* 44 * request a cookie to represent an object (index, datafile, xattr, etc) 45 * - parent specifies the parent object 46 * - the top level index cookie for each netfs is stored in the fscache_netfs 47 * struct upon registration 48 * - def points to the definition 49 * - the netfs_data will be passed to the functions pointed to in *def 50 * - all attached caches will be searched to see if they contain this object 51 * - index objects aren't stored on disk until there's a dependent file that 52 * needs storing 53 * - other objects are stored in a selected cache immediately, and all the 54 * indices forming the path to it are instantiated if necessary 55 * - we never let on to the netfs about errors 56 * - we may set a negative cookie pointer, but that's okay 57 */ 58 struct fscache_cookie *__fscache_acquire_cookie( 59 struct fscache_cookie *parent, 60 const struct fscache_cookie_def *def, 61 void *netfs_data, 62 bool enable) 63 { 64 struct fscache_cookie *cookie; 65 66 BUG_ON(!def); 67 68 _enter("{%s},{%s},%p,%u", 69 parent ? (char *) parent->def->name : "<no-parent>", 70 def->name, netfs_data, enable); 71 72 fscache_stat(&fscache_n_acquires); 73 74 /* if there's no parent cookie, then we don't create one here either */ 75 if (!parent) { 76 fscache_stat(&fscache_n_acquires_null); 77 _leave(" [no parent]"); 78 return NULL; 79 } 80 81 /* validate the definition */ 82 BUG_ON(!def->get_key); 83 BUG_ON(!def->name[0]); 84 85 BUG_ON(def->type == FSCACHE_COOKIE_TYPE_INDEX && 86 parent->def->type != FSCACHE_COOKIE_TYPE_INDEX); 87 88 /* allocate and initialise a cookie */ 89 cookie = kmem_cache_alloc(fscache_cookie_jar, GFP_KERNEL); 90 if (!cookie) { 91 fscache_stat(&fscache_n_acquires_oom); 92 _leave(" [ENOMEM]"); 93 return NULL; 94 } 95 96 atomic_set(&cookie->usage, 1); 97 atomic_set(&cookie->n_children, 0); 98 99 /* We keep the active count elevated until relinquishment to prevent an 100 * attempt to wake up every time the object operations queue quiesces. 101 */ 102 atomic_set(&cookie->n_active, 1); 103 104 atomic_inc(&parent->usage); 105 atomic_inc(&parent->n_children); 106 107 cookie->def = def; 108 cookie->parent = parent; 109 cookie->netfs_data = netfs_data; 110 cookie->flags = (1 << FSCACHE_COOKIE_NO_DATA_YET); 111 112 /* radix tree insertion won't use the preallocation pool unless it's 113 * told it may not wait */ 114 INIT_RADIX_TREE(&cookie->stores, GFP_NOFS & ~__GFP_WAIT); 115 116 switch (cookie->def->type) { 117 case FSCACHE_COOKIE_TYPE_INDEX: 118 fscache_stat(&fscache_n_cookie_index); 119 break; 120 case FSCACHE_COOKIE_TYPE_DATAFILE: 121 fscache_stat(&fscache_n_cookie_data); 122 break; 123 default: 124 fscache_stat(&fscache_n_cookie_special); 125 break; 126 } 127 128 if (enable) { 129 /* if the object is an index then we need do nothing more here 130 * - we create indices on disk when we need them as an index 131 * may exist in multiple caches */ 132 if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) { 133 if (fscache_acquire_non_index_cookie(cookie) == 0) { 134 set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); 135 } else { 136 atomic_dec(&parent->n_children); 137 __fscache_cookie_put(cookie); 138 fscache_stat(&fscache_n_acquires_nobufs); 139 _leave(" = NULL"); 140 return NULL; 141 } 142 } else { 143 set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); 144 } 145 } 146 147 fscache_stat(&fscache_n_acquires_ok); 148 _leave(" = %p", cookie); 149 return cookie; 150 } 151 EXPORT_SYMBOL(__fscache_acquire_cookie); 152 153 /* 154 * Enable a cookie to permit it to accept new operations. 155 */ 156 void __fscache_enable_cookie(struct fscache_cookie *cookie, 157 bool (*can_enable)(void *data), 158 void *data) 159 { 160 _enter("%p", cookie); 161 162 wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK, 163 TASK_UNINTERRUPTIBLE); 164 165 if (test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags)) 166 goto out_unlock; 167 168 if (can_enable && !can_enable(data)) { 169 /* The netfs decided it didn't want to enable after all */ 170 } else if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) { 171 /* Wait for outstanding disablement to complete */ 172 __fscache_wait_on_invalidate(cookie); 173 174 if (fscache_acquire_non_index_cookie(cookie) == 0) 175 set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); 176 } else { 177 set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); 178 } 179 180 out_unlock: 181 clear_bit_unlock(FSCACHE_COOKIE_ENABLEMENT_LOCK, &cookie->flags); 182 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK); 183 } 184 EXPORT_SYMBOL(__fscache_enable_cookie); 185 186 /* 187 * acquire a non-index cookie 188 * - this must make sure the index chain is instantiated and instantiate the 189 * object representation too 190 */ 191 static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie) 192 { 193 struct fscache_object *object; 194 struct fscache_cache *cache; 195 uint64_t i_size; 196 int ret; 197 198 _enter(""); 199 200 set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); 201 202 /* now we need to see whether the backing objects for this cookie yet 203 * exist, if not there'll be nothing to search */ 204 down_read(&fscache_addremove_sem); 205 206 if (list_empty(&fscache_cache_list)) { 207 up_read(&fscache_addremove_sem); 208 _leave(" = 0 [no caches]"); 209 return 0; 210 } 211 212 /* select a cache in which to store the object */ 213 cache = fscache_select_cache_for_object(cookie->parent); 214 if (!cache) { 215 up_read(&fscache_addremove_sem); 216 fscache_stat(&fscache_n_acquires_no_cache); 217 _leave(" = -ENOMEDIUM [no cache]"); 218 return -ENOMEDIUM; 219 } 220 221 _debug("cache %s", cache->tag->name); 222 223 set_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags); 224 225 /* ask the cache to allocate objects for this cookie and its parent 226 * chain */ 227 ret = fscache_alloc_object(cache, cookie); 228 if (ret < 0) { 229 up_read(&fscache_addremove_sem); 230 _leave(" = %d", ret); 231 return ret; 232 } 233 234 /* pass on how big the object we're caching is supposed to be */ 235 cookie->def->get_attr(cookie->netfs_data, &i_size); 236 237 spin_lock(&cookie->lock); 238 if (hlist_empty(&cookie->backing_objects)) { 239 spin_unlock(&cookie->lock); 240 goto unavailable; 241 } 242 243 object = hlist_entry(cookie->backing_objects.first, 244 struct fscache_object, cookie_link); 245 246 fscache_set_store_limit(object, i_size); 247 248 /* initiate the process of looking up all the objects in the chain 249 * (done by fscache_initialise_object()) */ 250 fscache_raise_event(object, FSCACHE_OBJECT_EV_NEW_CHILD); 251 252 spin_unlock(&cookie->lock); 253 254 /* we may be required to wait for lookup to complete at this point */ 255 if (!fscache_defer_lookup) { 256 _debug("non-deferred lookup %p", &cookie->flags); 257 wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP, 258 TASK_UNINTERRUPTIBLE); 259 _debug("complete"); 260 if (test_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags)) 261 goto unavailable; 262 } 263 264 up_read(&fscache_addremove_sem); 265 _leave(" = 0 [deferred]"); 266 return 0; 267 268 unavailable: 269 up_read(&fscache_addremove_sem); 270 _leave(" = -ENOBUFS"); 271 return -ENOBUFS; 272 } 273 274 /* 275 * recursively allocate cache object records for a cookie/cache combination 276 * - caller must be holding the addremove sem 277 */ 278 static int fscache_alloc_object(struct fscache_cache *cache, 279 struct fscache_cookie *cookie) 280 { 281 struct fscache_object *object; 282 int ret; 283 284 _enter("%p,%p{%s}", cache, cookie, cookie->def->name); 285 286 spin_lock(&cookie->lock); 287 hlist_for_each_entry(object, &cookie->backing_objects, 288 cookie_link) { 289 if (object->cache == cache) 290 goto object_already_extant; 291 } 292 spin_unlock(&cookie->lock); 293 294 /* ask the cache to allocate an object (we may end up with duplicate 295 * objects at this stage, but we sort that out later) */ 296 fscache_stat(&fscache_n_cop_alloc_object); 297 object = cache->ops->alloc_object(cache, cookie); 298 fscache_stat_d(&fscache_n_cop_alloc_object); 299 if (IS_ERR(object)) { 300 fscache_stat(&fscache_n_object_no_alloc); 301 ret = PTR_ERR(object); 302 goto error; 303 } 304 305 fscache_stat(&fscache_n_object_alloc); 306 307 object->debug_id = atomic_inc_return(&fscache_object_debug_id); 308 309 _debug("ALLOC OBJ%x: %s {%lx}", 310 object->debug_id, cookie->def->name, object->events); 311 312 ret = fscache_alloc_object(cache, cookie->parent); 313 if (ret < 0) 314 goto error_put; 315 316 /* only attach if we managed to allocate all we needed, otherwise 317 * discard the object we just allocated and instead use the one 318 * attached to the cookie */ 319 if (fscache_attach_object(cookie, object) < 0) { 320 fscache_stat(&fscache_n_cop_put_object); 321 cache->ops->put_object(object); 322 fscache_stat_d(&fscache_n_cop_put_object); 323 } 324 325 _leave(" = 0"); 326 return 0; 327 328 object_already_extant: 329 ret = -ENOBUFS; 330 if (fscache_object_is_dead(object)) { 331 spin_unlock(&cookie->lock); 332 goto error; 333 } 334 spin_unlock(&cookie->lock); 335 _leave(" = 0 [found]"); 336 return 0; 337 338 error_put: 339 fscache_stat(&fscache_n_cop_put_object); 340 cache->ops->put_object(object); 341 fscache_stat_d(&fscache_n_cop_put_object); 342 error: 343 _leave(" = %d", ret); 344 return ret; 345 } 346 347 /* 348 * attach a cache object to a cookie 349 */ 350 static int fscache_attach_object(struct fscache_cookie *cookie, 351 struct fscache_object *object) 352 { 353 struct fscache_object *p; 354 struct fscache_cache *cache = object->cache; 355 int ret; 356 357 _enter("{%s},{OBJ%x}", cookie->def->name, object->debug_id); 358 359 spin_lock(&cookie->lock); 360 361 /* there may be multiple initial creations of this object, but we only 362 * want one */ 363 ret = -EEXIST; 364 hlist_for_each_entry(p, &cookie->backing_objects, cookie_link) { 365 if (p->cache == object->cache) { 366 if (fscache_object_is_dying(p)) 367 ret = -ENOBUFS; 368 goto cant_attach_object; 369 } 370 } 371 372 /* pin the parent object */ 373 spin_lock_nested(&cookie->parent->lock, 1); 374 hlist_for_each_entry(p, &cookie->parent->backing_objects, 375 cookie_link) { 376 if (p->cache == object->cache) { 377 if (fscache_object_is_dying(p)) { 378 ret = -ENOBUFS; 379 spin_unlock(&cookie->parent->lock); 380 goto cant_attach_object; 381 } 382 object->parent = p; 383 spin_lock(&p->lock); 384 p->n_children++; 385 spin_unlock(&p->lock); 386 break; 387 } 388 } 389 spin_unlock(&cookie->parent->lock); 390 391 /* attach to the cache's object list */ 392 if (list_empty(&object->cache_link)) { 393 spin_lock(&cache->object_list_lock); 394 list_add(&object->cache_link, &cache->object_list); 395 spin_unlock(&cache->object_list_lock); 396 } 397 398 /* attach to the cookie */ 399 object->cookie = cookie; 400 atomic_inc(&cookie->usage); 401 hlist_add_head(&object->cookie_link, &cookie->backing_objects); 402 403 fscache_objlist_add(object); 404 ret = 0; 405 406 cant_attach_object: 407 spin_unlock(&cookie->lock); 408 _leave(" = %d", ret); 409 return ret; 410 } 411 412 /* 413 * Invalidate an object. Callable with spinlocks held. 414 */ 415 void __fscache_invalidate(struct fscache_cookie *cookie) 416 { 417 struct fscache_object *object; 418 419 _enter("{%s}", cookie->def->name); 420 421 fscache_stat(&fscache_n_invalidates); 422 423 /* Only permit invalidation of data files. Invalidating an index will 424 * require the caller to release all its attachments to the tree rooted 425 * there, and if it's doing that, it may as well just retire the 426 * cookie. 427 */ 428 ASSERTCMP(cookie->def->type, ==, FSCACHE_COOKIE_TYPE_DATAFILE); 429 430 /* We will be updating the cookie too. */ 431 BUG_ON(!cookie->def->get_aux); 432 433 /* If there's an object, we tell the object state machine to handle the 434 * invalidation on our behalf, otherwise there's nothing to do. 435 */ 436 if (!hlist_empty(&cookie->backing_objects)) { 437 spin_lock(&cookie->lock); 438 439 if (fscache_cookie_enabled(cookie) && 440 !hlist_empty(&cookie->backing_objects) && 441 !test_and_set_bit(FSCACHE_COOKIE_INVALIDATING, 442 &cookie->flags)) { 443 object = hlist_entry(cookie->backing_objects.first, 444 struct fscache_object, 445 cookie_link); 446 if (fscache_object_is_live(object)) 447 fscache_raise_event( 448 object, FSCACHE_OBJECT_EV_INVALIDATE); 449 } 450 451 spin_unlock(&cookie->lock); 452 } 453 454 _leave(""); 455 } 456 EXPORT_SYMBOL(__fscache_invalidate); 457 458 /* 459 * Wait for object invalidation to complete. 460 */ 461 void __fscache_wait_on_invalidate(struct fscache_cookie *cookie) 462 { 463 _enter("%p", cookie); 464 465 wait_on_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING, 466 TASK_UNINTERRUPTIBLE); 467 468 _leave(""); 469 } 470 EXPORT_SYMBOL(__fscache_wait_on_invalidate); 471 472 /* 473 * update the index entries backing a cookie 474 */ 475 void __fscache_update_cookie(struct fscache_cookie *cookie) 476 { 477 struct fscache_object *object; 478 479 fscache_stat(&fscache_n_updates); 480 481 if (!cookie) { 482 fscache_stat(&fscache_n_updates_null); 483 _leave(" [no cookie]"); 484 return; 485 } 486 487 _enter("{%s}", cookie->def->name); 488 489 BUG_ON(!cookie->def->get_aux); 490 491 spin_lock(&cookie->lock); 492 493 if (fscache_cookie_enabled(cookie)) { 494 /* update the index entry on disk in each cache backing this 495 * cookie. 496 */ 497 hlist_for_each_entry(object, 498 &cookie->backing_objects, cookie_link) { 499 fscache_raise_event(object, FSCACHE_OBJECT_EV_UPDATE); 500 } 501 } 502 503 spin_unlock(&cookie->lock); 504 _leave(""); 505 } 506 EXPORT_SYMBOL(__fscache_update_cookie); 507 508 /* 509 * Disable a cookie to stop it from accepting new requests from the netfs. 510 */ 511 void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate) 512 { 513 struct fscache_object *object; 514 bool awaken = false; 515 516 _enter("%p,%u", cookie, invalidate); 517 518 ASSERTCMP(atomic_read(&cookie->n_active), >, 0); 519 520 if (atomic_read(&cookie->n_children) != 0) { 521 pr_err("Cookie '%s' still has children\n", 522 cookie->def->name); 523 BUG(); 524 } 525 526 wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK, 527 TASK_UNINTERRUPTIBLE); 528 if (!test_and_clear_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags)) 529 goto out_unlock_enable; 530 531 /* If the cookie is being invalidated, wait for that to complete first 532 * so that we can reuse the flag. 533 */ 534 __fscache_wait_on_invalidate(cookie); 535 536 /* Dispose of the backing objects */ 537 set_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags); 538 539 spin_lock(&cookie->lock); 540 if (!hlist_empty(&cookie->backing_objects)) { 541 hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) { 542 if (invalidate) 543 set_bit(FSCACHE_OBJECT_RETIRED, &object->flags); 544 fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL); 545 } 546 } else { 547 if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) 548 awaken = true; 549 } 550 spin_unlock(&cookie->lock); 551 if (awaken) 552 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING); 553 554 /* Wait for cessation of activity requiring access to the netfs (when 555 * n_active reaches 0). This makes sure outstanding reads and writes 556 * have completed. 557 */ 558 if (!atomic_dec_and_test(&cookie->n_active)) 559 wait_on_atomic_t(&cookie->n_active, fscache_wait_atomic_t, 560 TASK_UNINTERRUPTIBLE); 561 562 /* Reset the cookie state if it wasn't relinquished */ 563 if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags)) { 564 atomic_inc(&cookie->n_active); 565 set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); 566 } 567 568 out_unlock_enable: 569 clear_bit_unlock(FSCACHE_COOKIE_ENABLEMENT_LOCK, &cookie->flags); 570 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK); 571 _leave(""); 572 } 573 EXPORT_SYMBOL(__fscache_disable_cookie); 574 575 /* 576 * release a cookie back to the cache 577 * - the object will be marked as recyclable on disk if retire is true 578 * - all dependents of this cookie must have already been unregistered 579 * (indices/files/pages) 580 */ 581 void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire) 582 { 583 fscache_stat(&fscache_n_relinquishes); 584 if (retire) 585 fscache_stat(&fscache_n_relinquishes_retire); 586 587 if (!cookie) { 588 fscache_stat(&fscache_n_relinquishes_null); 589 _leave(" [no cookie]"); 590 return; 591 } 592 593 _enter("%p{%s,%p,%d},%d", 594 cookie, cookie->def->name, cookie->netfs_data, 595 atomic_read(&cookie->n_active), retire); 596 597 /* No further netfs-accessing operations on this cookie permitted */ 598 set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags); 599 600 __fscache_disable_cookie(cookie, retire); 601 602 /* Clear pointers back to the netfs */ 603 cookie->netfs_data = NULL; 604 cookie->def = NULL; 605 BUG_ON(cookie->stores.rnode); 606 607 if (cookie->parent) { 608 ASSERTCMP(atomic_read(&cookie->parent->usage), >, 0); 609 ASSERTCMP(atomic_read(&cookie->parent->n_children), >, 0); 610 atomic_dec(&cookie->parent->n_children); 611 } 612 613 /* Dispose of the netfs's link to the cookie */ 614 ASSERTCMP(atomic_read(&cookie->usage), >, 0); 615 fscache_cookie_put(cookie); 616 617 _leave(""); 618 } 619 EXPORT_SYMBOL(__fscache_relinquish_cookie); 620 621 /* 622 * destroy a cookie 623 */ 624 void __fscache_cookie_put(struct fscache_cookie *cookie) 625 { 626 struct fscache_cookie *parent; 627 628 _enter("%p", cookie); 629 630 for (;;) { 631 _debug("FREE COOKIE %p", cookie); 632 parent = cookie->parent; 633 BUG_ON(!hlist_empty(&cookie->backing_objects)); 634 kmem_cache_free(fscache_cookie_jar, cookie); 635 636 if (!parent) 637 break; 638 639 cookie = parent; 640 BUG_ON(atomic_read(&cookie->usage) <= 0); 641 if (!atomic_dec_and_test(&cookie->usage)) 642 break; 643 } 644 645 _leave(""); 646 } 647 648 /* 649 * check the consistency between the netfs inode and the backing cache 650 * 651 * NOTE: it only serves no-index type 652 */ 653 int __fscache_check_consistency(struct fscache_cookie *cookie) 654 { 655 struct fscache_operation *op; 656 struct fscache_object *object; 657 bool wake_cookie = false; 658 int ret; 659 660 _enter("%p,", cookie); 661 662 ASSERTCMP(cookie->def->type, ==, FSCACHE_COOKIE_TYPE_DATAFILE); 663 664 if (fscache_wait_for_deferred_lookup(cookie) < 0) 665 return -ERESTARTSYS; 666 667 if (hlist_empty(&cookie->backing_objects)) 668 return 0; 669 670 op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY); 671 if (!op) 672 return -ENOMEM; 673 674 fscache_operation_init(op, NULL, NULL); 675 op->flags = FSCACHE_OP_MYTHREAD | 676 (1 << FSCACHE_OP_WAITING) | 677 (1 << FSCACHE_OP_UNUSE_COOKIE); 678 679 spin_lock(&cookie->lock); 680 681 if (!fscache_cookie_enabled(cookie) || 682 hlist_empty(&cookie->backing_objects)) 683 goto inconsistent; 684 object = hlist_entry(cookie->backing_objects.first, 685 struct fscache_object, cookie_link); 686 if (test_bit(FSCACHE_IOERROR, &object->cache->flags)) 687 goto inconsistent; 688 689 op->debug_id = atomic_inc_return(&fscache_op_debug_id); 690 691 __fscache_use_cookie(cookie); 692 if (fscache_submit_op(object, op) < 0) 693 goto submit_failed; 694 695 /* the work queue now carries its own ref on the object */ 696 spin_unlock(&cookie->lock); 697 698 ret = fscache_wait_for_operation_activation(object, op, 699 NULL, NULL, NULL); 700 if (ret == 0) { 701 /* ask the cache to honour the operation */ 702 ret = object->cache->ops->check_consistency(op); 703 fscache_op_complete(op, false); 704 } else if (ret == -ENOBUFS) { 705 ret = 0; 706 } 707 708 fscache_put_operation(op); 709 _leave(" = %d", ret); 710 return ret; 711 712 submit_failed: 713 wake_cookie = __fscache_unuse_cookie(cookie); 714 inconsistent: 715 spin_unlock(&cookie->lock); 716 if (wake_cookie) 717 __fscache_wake_unused_cookie(cookie); 718 kfree(op); 719 _leave(" = -ESTALE"); 720 return -ESTALE; 721 } 722 EXPORT_SYMBOL(__fscache_check_consistency); 723