1 /* 2 * net/sunrpc/cache.c 3 * 4 * Generic code for various authentication-related caches 5 * used by sunrpc clients and servers. 6 * 7 * Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au> 8 * 9 * Released under terms in GPL version 2. See COPYING. 10 * 11 */ 12 13 #include <linux/types.h> 14 #include <linux/fs.h> 15 #include <linux/file.h> 16 #include <linux/slab.h> 17 #include <linux/signal.h> 18 #include <linux/sched.h> 19 #include <linux/kmod.h> 20 #include <linux/list.h> 21 #include <linux/module.h> 22 #include <linux/ctype.h> 23 #include <asm/uaccess.h> 24 #include <linux/poll.h> 25 #include <linux/seq_file.h> 26 #include <linux/proc_fs.h> 27 #include <linux/net.h> 28 #include <linux/workqueue.h> 29 #include <linux/mutex.h> 30 #include <linux/pagemap.h> 31 #include <asm/ioctls.h> 32 #include <linux/sunrpc/types.h> 33 #include <linux/sunrpc/cache.h> 34 #include <linux/sunrpc/stats.h> 35 #include <linux/sunrpc/rpc_pipe_fs.h> 36 #include "netns.h" 37 38 #define RPCDBG_FACILITY RPCDBG_CACHE 39 40 static bool cache_defer_req(struct cache_req *req, struct cache_head *item); 41 static void cache_revisit_request(struct cache_head *item); 42 43 static void cache_init(struct cache_head *h) 44 { 45 time_t now = seconds_since_boot(); 46 h->next = NULL; 47 h->flags = 0; 48 kref_init(&h->ref); 49 h->expiry_time = now + CACHE_NEW_EXPIRY; 50 h->last_refresh = now; 51 } 52 53 static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h) 54 { 55 return (h->expiry_time < seconds_since_boot()) || 56 (detail->flush_time > h->last_refresh); 57 } 58 59 struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, 60 struct cache_head *key, int hash) 61 { 62 struct cache_head **head, **hp; 63 struct cache_head *new = NULL, *freeme = NULL; 64 65 head = &detail->hash_table[hash]; 66 67 read_lock(&detail->hash_lock); 68 69 for (hp=head; *hp != NULL ; hp = &(*hp)->next) { 70 struct cache_head *tmp = *hp; 71 if (detail->match(tmp, key)) { 72 if (cache_is_expired(detail, tmp)) 73 /* This entry is expired, we will discard it. */ 74 break; 75 cache_get(tmp); 76 read_unlock(&detail->hash_lock); 77 return tmp; 78 } 79 } 80 read_unlock(&detail->hash_lock); 81 /* Didn't find anything, insert an empty entry */ 82 83 new = detail->alloc(); 84 if (!new) 85 return NULL; 86 /* must fully initialise 'new', else 87 * we might get lose if we need to 88 * cache_put it soon. 89 */ 90 cache_init(new); 91 detail->init(new, key); 92 93 write_lock(&detail->hash_lock); 94 95 /* check if entry appeared while we slept */ 96 for (hp=head; *hp != NULL ; hp = &(*hp)->next) { 97 struct cache_head *tmp = *hp; 98 if (detail->match(tmp, key)) { 99 if (cache_is_expired(detail, tmp)) { 100 *hp = tmp->next; 101 tmp->next = NULL; 102 detail->entries --; 103 freeme = tmp; 104 break; 105 } 106 cache_get(tmp); 107 write_unlock(&detail->hash_lock); 108 cache_put(new, detail); 109 return tmp; 110 } 111 } 112 new->next = *head; 113 *head = new; 114 detail->entries++; 115 cache_get(new); 116 write_unlock(&detail->hash_lock); 117 118 if (freeme) 119 cache_put(freeme, detail); 120 return new; 121 } 122 EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); 123 124 125 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); 126 127 static void cache_fresh_locked(struct cache_head *head, time_t expiry) 128 { 129 head->expiry_time = expiry; 130 head->last_refresh = seconds_since_boot(); 131 smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */ 132 set_bit(CACHE_VALID, &head->flags); 133 } 134 135 static void cache_fresh_unlocked(struct cache_head *head, 136 struct cache_detail *detail) 137 { 138 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { 139 cache_revisit_request(head); 140 cache_dequeue(detail, head); 141 } 142 } 143 144 struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 145 struct cache_head *new, struct cache_head *old, int hash) 146 { 147 /* The 'old' entry is to be replaced by 'new'. 148 * If 'old' is not VALID, we update it directly, 149 * otherwise we need to replace it 150 */ 151 struct cache_head **head; 152 struct cache_head *tmp; 153 154 if (!test_bit(CACHE_VALID, &old->flags)) { 155 write_lock(&detail->hash_lock); 156 if (!test_bit(CACHE_VALID, &old->flags)) { 157 if (test_bit(CACHE_NEGATIVE, &new->flags)) 158 set_bit(CACHE_NEGATIVE, &old->flags); 159 else 160 detail->update(old, new); 161 cache_fresh_locked(old, new->expiry_time); 162 write_unlock(&detail->hash_lock); 163 cache_fresh_unlocked(old, detail); 164 return old; 165 } 166 write_unlock(&detail->hash_lock); 167 } 168 /* We need to insert a new entry */ 169 tmp = detail->alloc(); 170 if (!tmp) { 171 cache_put(old, detail); 172 return NULL; 173 } 174 cache_init(tmp); 175 detail->init(tmp, old); 176 head = &detail->hash_table[hash]; 177 178 write_lock(&detail->hash_lock); 179 if (test_bit(CACHE_NEGATIVE, &new->flags)) 180 set_bit(CACHE_NEGATIVE, &tmp->flags); 181 else 182 detail->update(tmp, new); 183 tmp->next = *head; 184 *head = tmp; 185 detail->entries++; 186 cache_get(tmp); 187 cache_fresh_locked(tmp, new->expiry_time); 188 cache_fresh_locked(old, 0); 189 write_unlock(&detail->hash_lock); 190 cache_fresh_unlocked(tmp, detail); 191 cache_fresh_unlocked(old, detail); 192 cache_put(old, detail); 193 return tmp; 194 } 195 EXPORT_SYMBOL_GPL(sunrpc_cache_update); 196 197 static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) 198 { 199 if (cd->cache_upcall) 200 return cd->cache_upcall(cd, h); 201 return sunrpc_cache_pipe_upcall(cd, h); 202 } 203 204 static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h) 205 { 206 if (!test_bit(CACHE_VALID, &h->flags)) 207 return -EAGAIN; 208 else { 209 /* entry is valid */ 210 if (test_bit(CACHE_NEGATIVE, &h->flags)) 211 return -ENOENT; 212 else { 213 /* 214 * In combination with write barrier in 215 * sunrpc_cache_update, ensures that anyone 216 * using the cache entry after this sees the 217 * updated contents: 218 */ 219 smp_rmb(); 220 return 0; 221 } 222 } 223 } 224 225 static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h) 226 { 227 int rv; 228 229 write_lock(&detail->hash_lock); 230 rv = cache_is_valid(detail, h); 231 if (rv != -EAGAIN) { 232 write_unlock(&detail->hash_lock); 233 return rv; 234 } 235 set_bit(CACHE_NEGATIVE, &h->flags); 236 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY); 237 write_unlock(&detail->hash_lock); 238 cache_fresh_unlocked(h, detail); 239 return -ENOENT; 240 } 241 242 /* 243 * This is the generic cache management routine for all 244 * the authentication caches. 245 * It checks the currency of a cache item and will (later) 246 * initiate an upcall to fill it if needed. 247 * 248 * 249 * Returns 0 if the cache_head can be used, or cache_puts it and returns 250 * -EAGAIN if upcall is pending and request has been queued 251 * -ETIMEDOUT if upcall failed or request could not be queue or 252 * upcall completed but item is still invalid (implying that 253 * the cache item has been replaced with a newer one). 254 * -ENOENT if cache entry was negative 255 */ 256 int cache_check(struct cache_detail *detail, 257 struct cache_head *h, struct cache_req *rqstp) 258 { 259 int rv; 260 long refresh_age, age; 261 262 /* First decide return status as best we can */ 263 rv = cache_is_valid(detail, h); 264 265 /* now see if we want to start an upcall */ 266 refresh_age = (h->expiry_time - h->last_refresh); 267 age = seconds_since_boot() - h->last_refresh; 268 269 if (rqstp == NULL) { 270 if (rv == -EAGAIN) 271 rv = -ENOENT; 272 } else if (rv == -EAGAIN || age > refresh_age/2) { 273 dprintk("RPC: Want update, refage=%ld, age=%ld\n", 274 refresh_age, age); 275 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { 276 switch (cache_make_upcall(detail, h)) { 277 case -EINVAL: 278 clear_bit(CACHE_PENDING, &h->flags); 279 cache_revisit_request(h); 280 rv = try_to_negate_entry(detail, h); 281 break; 282 case -EAGAIN: 283 clear_bit(CACHE_PENDING, &h->flags); 284 cache_revisit_request(h); 285 break; 286 } 287 } 288 } 289 290 if (rv == -EAGAIN) { 291 if (!cache_defer_req(rqstp, h)) { 292 /* 293 * Request was not deferred; handle it as best 294 * we can ourselves: 295 */ 296 rv = cache_is_valid(detail, h); 297 if (rv == -EAGAIN) 298 rv = -ETIMEDOUT; 299 } 300 } 301 if (rv) 302 cache_put(h, detail); 303 return rv; 304 } 305 EXPORT_SYMBOL_GPL(cache_check); 306 307 /* 308 * caches need to be periodically cleaned. 309 * For this we maintain a list of cache_detail and 310 * a current pointer into that list and into the table 311 * for that entry. 312 * 313 * Each time clean_cache is called it finds the next non-empty entry 314 * in the current table and walks the list in that entry 315 * looking for entries that can be removed. 316 * 317 * An entry gets removed if: 318 * - The expiry is before current time 319 * - The last_refresh time is before the flush_time for that cache 320 * 321 * later we might drop old entries with non-NEVER expiry if that table 322 * is getting 'full' for some definition of 'full' 323 * 324 * The question of "how often to scan a table" is an interesting one 325 * and is answered in part by the use of the "nextcheck" field in the 326 * cache_detail. 327 * When a scan of a table begins, the nextcheck field is set to a time 328 * that is well into the future. 329 * While scanning, if an expiry time is found that is earlier than the 330 * current nextcheck time, nextcheck is set to that expiry time. 331 * If the flush_time is ever set to a time earlier than the nextcheck 332 * time, the nextcheck time is then set to that flush_time. 333 * 334 * A table is then only scanned if the current time is at least 335 * the nextcheck time. 336 * 337 */ 338 339 static LIST_HEAD(cache_list); 340 static DEFINE_SPINLOCK(cache_list_lock); 341 static struct cache_detail *current_detail; 342 static int current_index; 343 344 static void do_cache_clean(struct work_struct *work); 345 static struct delayed_work cache_cleaner; 346 347 void sunrpc_init_cache_detail(struct cache_detail *cd) 348 { 349 rwlock_init(&cd->hash_lock); 350 INIT_LIST_HEAD(&cd->queue); 351 spin_lock(&cache_list_lock); 352 cd->nextcheck = 0; 353 cd->entries = 0; 354 atomic_set(&cd->readers, 0); 355 cd->last_close = 0; 356 cd->last_warn = -1; 357 list_add(&cd->others, &cache_list); 358 spin_unlock(&cache_list_lock); 359 360 /* start the cleaning process */ 361 schedule_delayed_work(&cache_cleaner, 0); 362 } 363 EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail); 364 365 void sunrpc_destroy_cache_detail(struct cache_detail *cd) 366 { 367 cache_purge(cd); 368 spin_lock(&cache_list_lock); 369 write_lock(&cd->hash_lock); 370 if (cd->entries || atomic_read(&cd->inuse)) { 371 write_unlock(&cd->hash_lock); 372 spin_unlock(&cache_list_lock); 373 goto out; 374 } 375 if (current_detail == cd) 376 current_detail = NULL; 377 list_del_init(&cd->others); 378 write_unlock(&cd->hash_lock); 379 spin_unlock(&cache_list_lock); 380 if (list_empty(&cache_list)) { 381 /* module must be being unloaded so its safe to kill the worker */ 382 cancel_delayed_work_sync(&cache_cleaner); 383 } 384 return; 385 out: 386 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name); 387 } 388 EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail); 389 390 /* clean cache tries to find something to clean 391 * and cleans it. 392 * It returns 1 if it cleaned something, 393 * 0 if it didn't find anything this time 394 * -1 if it fell off the end of the list. 395 */ 396 static int cache_clean(void) 397 { 398 int rv = 0; 399 struct list_head *next; 400 401 spin_lock(&cache_list_lock); 402 403 /* find a suitable table if we don't already have one */ 404 while (current_detail == NULL || 405 current_index >= current_detail->hash_size) { 406 if (current_detail) 407 next = current_detail->others.next; 408 else 409 next = cache_list.next; 410 if (next == &cache_list) { 411 current_detail = NULL; 412 spin_unlock(&cache_list_lock); 413 return -1; 414 } 415 current_detail = list_entry(next, struct cache_detail, others); 416 if (current_detail->nextcheck > seconds_since_boot()) 417 current_index = current_detail->hash_size; 418 else { 419 current_index = 0; 420 current_detail->nextcheck = seconds_since_boot()+30*60; 421 } 422 } 423 424 /* find a non-empty bucket in the table */ 425 while (current_detail && 426 current_index < current_detail->hash_size && 427 current_detail->hash_table[current_index] == NULL) 428 current_index++; 429 430 /* find a cleanable entry in the bucket and clean it, or set to next bucket */ 431 432 if (current_detail && current_index < current_detail->hash_size) { 433 struct cache_head *ch, **cp; 434 struct cache_detail *d; 435 436 write_lock(¤t_detail->hash_lock); 437 438 /* Ok, now to clean this strand */ 439 440 cp = & current_detail->hash_table[current_index]; 441 for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) { 442 if (current_detail->nextcheck > ch->expiry_time) 443 current_detail->nextcheck = ch->expiry_time+1; 444 if (!cache_is_expired(current_detail, ch)) 445 continue; 446 447 *cp = ch->next; 448 ch->next = NULL; 449 current_detail->entries--; 450 rv = 1; 451 break; 452 } 453 454 write_unlock(¤t_detail->hash_lock); 455 d = current_detail; 456 if (!ch) 457 current_index ++; 458 spin_unlock(&cache_list_lock); 459 if (ch) { 460 if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) 461 cache_dequeue(current_detail, ch); 462 cache_revisit_request(ch); 463 cache_put(ch, d); 464 } 465 } else 466 spin_unlock(&cache_list_lock); 467 468 return rv; 469 } 470 471 /* 472 * We want to regularly clean the cache, so we need to schedule some work ... 473 */ 474 static void do_cache_clean(struct work_struct *work) 475 { 476 int delay = 5; 477 if (cache_clean() == -1) 478 delay = round_jiffies_relative(30*HZ); 479 480 if (list_empty(&cache_list)) 481 delay = 0; 482 483 if (delay) 484 schedule_delayed_work(&cache_cleaner, delay); 485 } 486 487 488 /* 489 * Clean all caches promptly. This just calls cache_clean 490 * repeatedly until we are sure that every cache has had a chance to 491 * be fully cleaned 492 */ 493 void cache_flush(void) 494 { 495 while (cache_clean() != -1) 496 cond_resched(); 497 while (cache_clean() != -1) 498 cond_resched(); 499 } 500 EXPORT_SYMBOL_GPL(cache_flush); 501 502 void cache_purge(struct cache_detail *detail) 503 { 504 detail->flush_time = LONG_MAX; 505 detail->nextcheck = seconds_since_boot(); 506 cache_flush(); 507 detail->flush_time = 1; 508 } 509 EXPORT_SYMBOL_GPL(cache_purge); 510 511 512 /* 513 * Deferral and Revisiting of Requests. 514 * 515 * If a cache lookup finds a pending entry, we 516 * need to defer the request and revisit it later. 517 * All deferred requests are stored in a hash table, 518 * indexed by "struct cache_head *". 519 * As it may be wasteful to store a whole request 520 * structure, we allow the request to provide a 521 * deferred form, which must contain a 522 * 'struct cache_deferred_req' 523 * This cache_deferred_req contains a method to allow 524 * it to be revisited when cache info is available 525 */ 526 527 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) 528 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) 529 530 #define DFR_MAX 300 /* ??? */ 531 532 static DEFINE_SPINLOCK(cache_defer_lock); 533 static LIST_HEAD(cache_defer_list); 534 static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; 535 static int cache_defer_cnt; 536 537 static void __unhash_deferred_req(struct cache_deferred_req *dreq) 538 { 539 hlist_del_init(&dreq->hash); 540 if (!list_empty(&dreq->recent)) { 541 list_del_init(&dreq->recent); 542 cache_defer_cnt--; 543 } 544 } 545 546 static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item) 547 { 548 int hash = DFR_HASH(item); 549 550 INIT_LIST_HEAD(&dreq->recent); 551 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]); 552 } 553 554 static void setup_deferral(struct cache_deferred_req *dreq, 555 struct cache_head *item, 556 int count_me) 557 { 558 559 dreq->item = item; 560 561 spin_lock(&cache_defer_lock); 562 563 __hash_deferred_req(dreq, item); 564 565 if (count_me) { 566 cache_defer_cnt++; 567 list_add(&dreq->recent, &cache_defer_list); 568 } 569 570 spin_unlock(&cache_defer_lock); 571 572 } 573 574 struct thread_deferred_req { 575 struct cache_deferred_req handle; 576 struct completion completion; 577 }; 578 579 static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) 580 { 581 struct thread_deferred_req *dr = 582 container_of(dreq, struct thread_deferred_req, handle); 583 complete(&dr->completion); 584 } 585 586 static void cache_wait_req(struct cache_req *req, struct cache_head *item) 587 { 588 struct thread_deferred_req sleeper; 589 struct cache_deferred_req *dreq = &sleeper.handle; 590 591 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); 592 dreq->revisit = cache_restart_thread; 593 594 setup_deferral(dreq, item, 0); 595 596 if (!test_bit(CACHE_PENDING, &item->flags) || 597 wait_for_completion_interruptible_timeout( 598 &sleeper.completion, req->thread_wait) <= 0) { 599 /* The completion wasn't completed, so we need 600 * to clean up 601 */ 602 spin_lock(&cache_defer_lock); 603 if (!hlist_unhashed(&sleeper.handle.hash)) { 604 __unhash_deferred_req(&sleeper.handle); 605 spin_unlock(&cache_defer_lock); 606 } else { 607 /* cache_revisit_request already removed 608 * this from the hash table, but hasn't 609 * called ->revisit yet. It will very soon 610 * and we need to wait for it. 611 */ 612 spin_unlock(&cache_defer_lock); 613 wait_for_completion(&sleeper.completion); 614 } 615 } 616 } 617 618 static void cache_limit_defers(void) 619 { 620 /* Make sure we haven't exceed the limit of allowed deferred 621 * requests. 622 */ 623 struct cache_deferred_req *discard = NULL; 624 625 if (cache_defer_cnt <= DFR_MAX) 626 return; 627 628 spin_lock(&cache_defer_lock); 629 630 /* Consider removing either the first or the last */ 631 if (cache_defer_cnt > DFR_MAX) { 632 if (net_random() & 1) 633 discard = list_entry(cache_defer_list.next, 634 struct cache_deferred_req, recent); 635 else 636 discard = list_entry(cache_defer_list.prev, 637 struct cache_deferred_req, recent); 638 __unhash_deferred_req(discard); 639 } 640 spin_unlock(&cache_defer_lock); 641 if (discard) 642 discard->revisit(discard, 1); 643 } 644 645 /* Return true if and only if a deferred request is queued. */ 646 static bool cache_defer_req(struct cache_req *req, struct cache_head *item) 647 { 648 struct cache_deferred_req *dreq; 649 650 if (req->thread_wait) { 651 cache_wait_req(req, item); 652 if (!test_bit(CACHE_PENDING, &item->flags)) 653 return false; 654 } 655 dreq = req->defer(req); 656 if (dreq == NULL) 657 return false; 658 setup_deferral(dreq, item, 1); 659 if (!test_bit(CACHE_PENDING, &item->flags)) 660 /* Bit could have been cleared before we managed to 661 * set up the deferral, so need to revisit just in case 662 */ 663 cache_revisit_request(item); 664 665 cache_limit_defers(); 666 return true; 667 } 668 669 static void cache_revisit_request(struct cache_head *item) 670 { 671 struct cache_deferred_req *dreq; 672 struct list_head pending; 673 struct hlist_node *tmp; 674 int hash = DFR_HASH(item); 675 676 INIT_LIST_HEAD(&pending); 677 spin_lock(&cache_defer_lock); 678 679 hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash) 680 if (dreq->item == item) { 681 __unhash_deferred_req(dreq); 682 list_add(&dreq->recent, &pending); 683 } 684 685 spin_unlock(&cache_defer_lock); 686 687 while (!list_empty(&pending)) { 688 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 689 list_del_init(&dreq->recent); 690 dreq->revisit(dreq, 0); 691 } 692 } 693 694 void cache_clean_deferred(void *owner) 695 { 696 struct cache_deferred_req *dreq, *tmp; 697 struct list_head pending; 698 699 700 INIT_LIST_HEAD(&pending); 701 spin_lock(&cache_defer_lock); 702 703 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { 704 if (dreq->owner == owner) { 705 __unhash_deferred_req(dreq); 706 list_add(&dreq->recent, &pending); 707 } 708 } 709 spin_unlock(&cache_defer_lock); 710 711 while (!list_empty(&pending)) { 712 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 713 list_del_init(&dreq->recent); 714 dreq->revisit(dreq, 1); 715 } 716 } 717 718 /* 719 * communicate with user-space 720 * 721 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. 722 * On read, you get a full request, or block. 723 * On write, an update request is processed. 724 * Poll works if anything to read, and always allows write. 725 * 726 * Implemented by linked list of requests. Each open file has 727 * a ->private that also exists in this list. New requests are added 728 * to the end and may wakeup and preceding readers. 729 * New readers are added to the head. If, on read, an item is found with 730 * CACHE_UPCALLING clear, we free it from the list. 731 * 732 */ 733 734 static DEFINE_SPINLOCK(queue_lock); 735 static DEFINE_MUTEX(queue_io_mutex); 736 737 struct cache_queue { 738 struct list_head list; 739 int reader; /* if 0, then request */ 740 }; 741 struct cache_request { 742 struct cache_queue q; 743 struct cache_head *item; 744 char * buf; 745 int len; 746 int readers; 747 }; 748 struct cache_reader { 749 struct cache_queue q; 750 int offset; /* if non-0, we have a refcnt on next request */ 751 }; 752 753 static int cache_request(struct cache_detail *detail, 754 struct cache_request *crq) 755 { 756 char *bp = crq->buf; 757 int len = PAGE_SIZE; 758 759 detail->cache_request(detail, crq->item, &bp, &len); 760 if (len < 0) 761 return -EAGAIN; 762 return PAGE_SIZE - len; 763 } 764 765 static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, 766 loff_t *ppos, struct cache_detail *cd) 767 { 768 struct cache_reader *rp = filp->private_data; 769 struct cache_request *rq; 770 struct inode *inode = file_inode(filp); 771 int err; 772 773 if (count == 0) 774 return 0; 775 776 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent 777 * readers on this file */ 778 again: 779 spin_lock(&queue_lock); 780 /* need to find next request */ 781 while (rp->q.list.next != &cd->queue && 782 list_entry(rp->q.list.next, struct cache_queue, list) 783 ->reader) { 784 struct list_head *next = rp->q.list.next; 785 list_move(&rp->q.list, next); 786 } 787 if (rp->q.list.next == &cd->queue) { 788 spin_unlock(&queue_lock); 789 mutex_unlock(&inode->i_mutex); 790 WARN_ON_ONCE(rp->offset); 791 return 0; 792 } 793 rq = container_of(rp->q.list.next, struct cache_request, q.list); 794 WARN_ON_ONCE(rq->q.reader); 795 if (rp->offset == 0) 796 rq->readers++; 797 spin_unlock(&queue_lock); 798 799 if (rq->len == 0) { 800 err = cache_request(cd, rq); 801 if (err < 0) 802 goto out; 803 rq->len = err; 804 } 805 806 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { 807 err = -EAGAIN; 808 spin_lock(&queue_lock); 809 list_move(&rp->q.list, &rq->q.list); 810 spin_unlock(&queue_lock); 811 } else { 812 if (rp->offset + count > rq->len) 813 count = rq->len - rp->offset; 814 err = -EFAULT; 815 if (copy_to_user(buf, rq->buf + rp->offset, count)) 816 goto out; 817 rp->offset += count; 818 if (rp->offset >= rq->len) { 819 rp->offset = 0; 820 spin_lock(&queue_lock); 821 list_move(&rp->q.list, &rq->q.list); 822 spin_unlock(&queue_lock); 823 } 824 err = 0; 825 } 826 out: 827 if (rp->offset == 0) { 828 /* need to release rq */ 829 spin_lock(&queue_lock); 830 rq->readers--; 831 if (rq->readers == 0 && 832 !test_bit(CACHE_PENDING, &rq->item->flags)) { 833 list_del(&rq->q.list); 834 spin_unlock(&queue_lock); 835 cache_put(rq->item, cd); 836 kfree(rq->buf); 837 kfree(rq); 838 } else 839 spin_unlock(&queue_lock); 840 } 841 if (err == -EAGAIN) 842 goto again; 843 mutex_unlock(&inode->i_mutex); 844 return err ? err : count; 845 } 846 847 static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, 848 size_t count, struct cache_detail *cd) 849 { 850 ssize_t ret; 851 852 if (count == 0) 853 return -EINVAL; 854 if (copy_from_user(kaddr, buf, count)) 855 return -EFAULT; 856 kaddr[count] = '\0'; 857 ret = cd->cache_parse(cd, kaddr, count); 858 if (!ret) 859 ret = count; 860 return ret; 861 } 862 863 static ssize_t cache_slow_downcall(const char __user *buf, 864 size_t count, struct cache_detail *cd) 865 { 866 static char write_buf[8192]; /* protected by queue_io_mutex */ 867 ssize_t ret = -EINVAL; 868 869 if (count >= sizeof(write_buf)) 870 goto out; 871 mutex_lock(&queue_io_mutex); 872 ret = cache_do_downcall(write_buf, buf, count, cd); 873 mutex_unlock(&queue_io_mutex); 874 out: 875 return ret; 876 } 877 878 static ssize_t cache_downcall(struct address_space *mapping, 879 const char __user *buf, 880 size_t count, struct cache_detail *cd) 881 { 882 struct page *page; 883 char *kaddr; 884 ssize_t ret = -ENOMEM; 885 886 if (count >= PAGE_CACHE_SIZE) 887 goto out_slow; 888 889 page = find_or_create_page(mapping, 0, GFP_KERNEL); 890 if (!page) 891 goto out_slow; 892 893 kaddr = kmap(page); 894 ret = cache_do_downcall(kaddr, buf, count, cd); 895 kunmap(page); 896 unlock_page(page); 897 page_cache_release(page); 898 return ret; 899 out_slow: 900 return cache_slow_downcall(buf, count, cd); 901 } 902 903 static ssize_t cache_write(struct file *filp, const char __user *buf, 904 size_t count, loff_t *ppos, 905 struct cache_detail *cd) 906 { 907 struct address_space *mapping = filp->f_mapping; 908 struct inode *inode = file_inode(filp); 909 ssize_t ret = -EINVAL; 910 911 if (!cd->cache_parse) 912 goto out; 913 914 mutex_lock(&inode->i_mutex); 915 ret = cache_downcall(mapping, buf, count, cd); 916 mutex_unlock(&inode->i_mutex); 917 out: 918 return ret; 919 } 920 921 static DECLARE_WAIT_QUEUE_HEAD(queue_wait); 922 923 static unsigned int cache_poll(struct file *filp, poll_table *wait, 924 struct cache_detail *cd) 925 { 926 unsigned int mask; 927 struct cache_reader *rp = filp->private_data; 928 struct cache_queue *cq; 929 930 poll_wait(filp, &queue_wait, wait); 931 932 /* alway allow write */ 933 mask = POLL_OUT | POLLWRNORM; 934 935 if (!rp) 936 return mask; 937 938 spin_lock(&queue_lock); 939 940 for (cq= &rp->q; &cq->list != &cd->queue; 941 cq = list_entry(cq->list.next, struct cache_queue, list)) 942 if (!cq->reader) { 943 mask |= POLLIN | POLLRDNORM; 944 break; 945 } 946 spin_unlock(&queue_lock); 947 return mask; 948 } 949 950 static int cache_ioctl(struct inode *ino, struct file *filp, 951 unsigned int cmd, unsigned long arg, 952 struct cache_detail *cd) 953 { 954 int len = 0; 955 struct cache_reader *rp = filp->private_data; 956 struct cache_queue *cq; 957 958 if (cmd != FIONREAD || !rp) 959 return -EINVAL; 960 961 spin_lock(&queue_lock); 962 963 /* only find the length remaining in current request, 964 * or the length of the next request 965 */ 966 for (cq= &rp->q; &cq->list != &cd->queue; 967 cq = list_entry(cq->list.next, struct cache_queue, list)) 968 if (!cq->reader) { 969 struct cache_request *cr = 970 container_of(cq, struct cache_request, q); 971 len = cr->len - rp->offset; 972 break; 973 } 974 spin_unlock(&queue_lock); 975 976 return put_user(len, (int __user *)arg); 977 } 978 979 static int cache_open(struct inode *inode, struct file *filp, 980 struct cache_detail *cd) 981 { 982 struct cache_reader *rp = NULL; 983 984 if (!cd || !try_module_get(cd->owner)) 985 return -EACCES; 986 nonseekable_open(inode, filp); 987 if (filp->f_mode & FMODE_READ) { 988 rp = kmalloc(sizeof(*rp), GFP_KERNEL); 989 if (!rp) 990 return -ENOMEM; 991 rp->offset = 0; 992 rp->q.reader = 1; 993 atomic_inc(&cd->readers); 994 spin_lock(&queue_lock); 995 list_add(&rp->q.list, &cd->queue); 996 spin_unlock(&queue_lock); 997 } 998 filp->private_data = rp; 999 return 0; 1000 } 1001 1002 static int cache_release(struct inode *inode, struct file *filp, 1003 struct cache_detail *cd) 1004 { 1005 struct cache_reader *rp = filp->private_data; 1006 1007 if (rp) { 1008 spin_lock(&queue_lock); 1009 if (rp->offset) { 1010 struct cache_queue *cq; 1011 for (cq= &rp->q; &cq->list != &cd->queue; 1012 cq = list_entry(cq->list.next, struct cache_queue, list)) 1013 if (!cq->reader) { 1014 container_of(cq, struct cache_request, q) 1015 ->readers--; 1016 break; 1017 } 1018 rp->offset = 0; 1019 } 1020 list_del(&rp->q.list); 1021 spin_unlock(&queue_lock); 1022 1023 filp->private_data = NULL; 1024 kfree(rp); 1025 1026 cd->last_close = seconds_since_boot(); 1027 atomic_dec(&cd->readers); 1028 } 1029 module_put(cd->owner); 1030 return 0; 1031 } 1032 1033 1034 1035 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) 1036 { 1037 struct cache_queue *cq; 1038 spin_lock(&queue_lock); 1039 list_for_each_entry(cq, &detail->queue, list) 1040 if (!cq->reader) { 1041 struct cache_request *cr = container_of(cq, struct cache_request, q); 1042 if (cr->item != ch) 1043 continue; 1044 if (cr->readers != 0) 1045 continue; 1046 list_del(&cr->q.list); 1047 spin_unlock(&queue_lock); 1048 cache_put(cr->item, detail); 1049 kfree(cr->buf); 1050 kfree(cr); 1051 return; 1052 } 1053 spin_unlock(&queue_lock); 1054 } 1055 1056 /* 1057 * Support routines for text-based upcalls. 1058 * Fields are separated by spaces. 1059 * Fields are either mangled to quote space tab newline slosh with slosh 1060 * or a hexified with a leading \x 1061 * Record is terminated with newline. 1062 * 1063 */ 1064 1065 void qword_add(char **bpp, int *lp, char *str) 1066 { 1067 char *bp = *bpp; 1068 int len = *lp; 1069 char c; 1070 1071 if (len < 0) return; 1072 1073 while ((c=*str++) && len) 1074 switch(c) { 1075 case ' ': 1076 case '\t': 1077 case '\n': 1078 case '\\': 1079 if (len >= 4) { 1080 *bp++ = '\\'; 1081 *bp++ = '0' + ((c & 0300)>>6); 1082 *bp++ = '0' + ((c & 0070)>>3); 1083 *bp++ = '0' + ((c & 0007)>>0); 1084 } 1085 len -= 4; 1086 break; 1087 default: 1088 *bp++ = c; 1089 len--; 1090 } 1091 if (c || len <1) len = -1; 1092 else { 1093 *bp++ = ' '; 1094 len--; 1095 } 1096 *bpp = bp; 1097 *lp = len; 1098 } 1099 EXPORT_SYMBOL_GPL(qword_add); 1100 1101 void qword_addhex(char **bpp, int *lp, char *buf, int blen) 1102 { 1103 char *bp = *bpp; 1104 int len = *lp; 1105 1106 if (len < 0) return; 1107 1108 if (len > 2) { 1109 *bp++ = '\\'; 1110 *bp++ = 'x'; 1111 len -= 2; 1112 while (blen && len >= 2) { 1113 unsigned char c = *buf++; 1114 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 1115 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 1116 len -= 2; 1117 blen--; 1118 } 1119 } 1120 if (blen || len<1) len = -1; 1121 else { 1122 *bp++ = ' '; 1123 len--; 1124 } 1125 *bpp = bp; 1126 *lp = len; 1127 } 1128 EXPORT_SYMBOL_GPL(qword_addhex); 1129 1130 static void warn_no_listener(struct cache_detail *detail) 1131 { 1132 if (detail->last_warn != detail->last_close) { 1133 detail->last_warn = detail->last_close; 1134 if (detail->warn_no_listener) 1135 detail->warn_no_listener(detail, detail->last_close != 0); 1136 } 1137 } 1138 1139 static bool cache_listeners_exist(struct cache_detail *detail) 1140 { 1141 if (atomic_read(&detail->readers)) 1142 return true; 1143 if (detail->last_close == 0) 1144 /* This cache was never opened */ 1145 return false; 1146 if (detail->last_close < seconds_since_boot() - 30) 1147 /* 1148 * We allow for the possibility that someone might 1149 * restart a userspace daemon without restarting the 1150 * server; but after 30 seconds, we give up. 1151 */ 1152 return false; 1153 return true; 1154 } 1155 1156 /* 1157 * register an upcall request to user-space and queue it up for read() by the 1158 * upcall daemon. 1159 * 1160 * Each request is at most one page long. 1161 */ 1162 int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) 1163 { 1164 1165 char *buf; 1166 struct cache_request *crq; 1167 1168 if (!detail->cache_request) 1169 return -EINVAL; 1170 1171 if (!cache_listeners_exist(detail)) { 1172 warn_no_listener(detail); 1173 return -EINVAL; 1174 } 1175 1176 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 1177 if (!buf) 1178 return -EAGAIN; 1179 1180 crq = kmalloc(sizeof (*crq), GFP_KERNEL); 1181 if (!crq) { 1182 kfree(buf); 1183 return -EAGAIN; 1184 } 1185 1186 crq->q.reader = 0; 1187 crq->item = cache_get(h); 1188 crq->buf = buf; 1189 crq->len = 0; 1190 crq->readers = 0; 1191 spin_lock(&queue_lock); 1192 list_add_tail(&crq->q.list, &detail->queue); 1193 spin_unlock(&queue_lock); 1194 wake_up(&queue_wait); 1195 return 0; 1196 } 1197 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); 1198 1199 /* 1200 * parse a message from user-space and pass it 1201 * to an appropriate cache 1202 * Messages are, like requests, separated into fields by 1203 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal 1204 * 1205 * Message is 1206 * reply cachename expiry key ... content.... 1207 * 1208 * key and content are both parsed by cache 1209 */ 1210 1211 #define isodigit(c) (isdigit(c) && c <= '7') 1212 int qword_get(char **bpp, char *dest, int bufsize) 1213 { 1214 /* return bytes copied, or -1 on error */ 1215 char *bp = *bpp; 1216 int len = 0; 1217 1218 while (*bp == ' ') bp++; 1219 1220 if (bp[0] == '\\' && bp[1] == 'x') { 1221 /* HEX STRING */ 1222 bp += 2; 1223 while (len < bufsize) { 1224 int h, l; 1225 1226 h = hex_to_bin(bp[0]); 1227 if (h < 0) 1228 break; 1229 1230 l = hex_to_bin(bp[1]); 1231 if (l < 0) 1232 break; 1233 1234 *dest++ = (h << 4) | l; 1235 bp += 2; 1236 len++; 1237 } 1238 } else { 1239 /* text with \nnn octal quoting */ 1240 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { 1241 if (*bp == '\\' && 1242 isodigit(bp[1]) && (bp[1] <= '3') && 1243 isodigit(bp[2]) && 1244 isodigit(bp[3])) { 1245 int byte = (*++bp -'0'); 1246 bp++; 1247 byte = (byte << 3) | (*bp++ - '0'); 1248 byte = (byte << 3) | (*bp++ - '0'); 1249 *dest++ = byte; 1250 len++; 1251 } else { 1252 *dest++ = *bp++; 1253 len++; 1254 } 1255 } 1256 } 1257 1258 if (*bp != ' ' && *bp != '\n' && *bp != '\0') 1259 return -1; 1260 while (*bp == ' ') bp++; 1261 *bpp = bp; 1262 *dest = '\0'; 1263 return len; 1264 } 1265 EXPORT_SYMBOL_GPL(qword_get); 1266 1267 1268 /* 1269 * support /proc/sunrpc/cache/$CACHENAME/content 1270 * as a seqfile. 1271 * We call ->cache_show passing NULL for the item to 1272 * get a header, then pass each real item in the cache 1273 */ 1274 1275 struct handle { 1276 struct cache_detail *cd; 1277 }; 1278 1279 static void *c_start(struct seq_file *m, loff_t *pos) 1280 __acquires(cd->hash_lock) 1281 { 1282 loff_t n = *pos; 1283 unsigned int hash, entry; 1284 struct cache_head *ch; 1285 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1286 1287 1288 read_lock(&cd->hash_lock); 1289 if (!n--) 1290 return SEQ_START_TOKEN; 1291 hash = n >> 32; 1292 entry = n & ((1LL<<32) - 1); 1293 1294 for (ch=cd->hash_table[hash]; ch; ch=ch->next) 1295 if (!entry--) 1296 return ch; 1297 n &= ~((1LL<<32) - 1); 1298 do { 1299 hash++; 1300 n += 1LL<<32; 1301 } while(hash < cd->hash_size && 1302 cd->hash_table[hash]==NULL); 1303 if (hash >= cd->hash_size) 1304 return NULL; 1305 *pos = n+1; 1306 return cd->hash_table[hash]; 1307 } 1308 1309 static void *c_next(struct seq_file *m, void *p, loff_t *pos) 1310 { 1311 struct cache_head *ch = p; 1312 int hash = (*pos >> 32); 1313 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1314 1315 if (p == SEQ_START_TOKEN) 1316 hash = 0; 1317 else if (ch->next == NULL) { 1318 hash++; 1319 *pos += 1LL<<32; 1320 } else { 1321 ++*pos; 1322 return ch->next; 1323 } 1324 *pos &= ~((1LL<<32) - 1); 1325 while (hash < cd->hash_size && 1326 cd->hash_table[hash] == NULL) { 1327 hash++; 1328 *pos += 1LL<<32; 1329 } 1330 if (hash >= cd->hash_size) 1331 return NULL; 1332 ++*pos; 1333 return cd->hash_table[hash]; 1334 } 1335 1336 static void c_stop(struct seq_file *m, void *p) 1337 __releases(cd->hash_lock) 1338 { 1339 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1340 read_unlock(&cd->hash_lock); 1341 } 1342 1343 static int c_show(struct seq_file *m, void *p) 1344 { 1345 struct cache_head *cp = p; 1346 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1347 1348 if (p == SEQ_START_TOKEN) 1349 return cd->cache_show(m, cd, NULL); 1350 1351 ifdebug(CACHE) 1352 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", 1353 convert_to_wallclock(cp->expiry_time), 1354 atomic_read(&cp->ref.refcount), cp->flags); 1355 cache_get(cp); 1356 if (cache_check(cd, cp, NULL)) 1357 /* cache_check does a cache_put on failure */ 1358 seq_printf(m, "# "); 1359 else { 1360 if (cache_is_expired(cd, cp)) 1361 seq_printf(m, "# "); 1362 cache_put(cp, cd); 1363 } 1364 1365 return cd->cache_show(m, cd, cp); 1366 } 1367 1368 static const struct seq_operations cache_content_op = { 1369 .start = c_start, 1370 .next = c_next, 1371 .stop = c_stop, 1372 .show = c_show, 1373 }; 1374 1375 static int content_open(struct inode *inode, struct file *file, 1376 struct cache_detail *cd) 1377 { 1378 struct handle *han; 1379 1380 if (!cd || !try_module_get(cd->owner)) 1381 return -EACCES; 1382 han = __seq_open_private(file, &cache_content_op, sizeof(*han)); 1383 if (han == NULL) { 1384 module_put(cd->owner); 1385 return -ENOMEM; 1386 } 1387 1388 han->cd = cd; 1389 return 0; 1390 } 1391 1392 static int content_release(struct inode *inode, struct file *file, 1393 struct cache_detail *cd) 1394 { 1395 int ret = seq_release_private(inode, file); 1396 module_put(cd->owner); 1397 return ret; 1398 } 1399 1400 static int open_flush(struct inode *inode, struct file *file, 1401 struct cache_detail *cd) 1402 { 1403 if (!cd || !try_module_get(cd->owner)) 1404 return -EACCES; 1405 return nonseekable_open(inode, file); 1406 } 1407 1408 static int release_flush(struct inode *inode, struct file *file, 1409 struct cache_detail *cd) 1410 { 1411 module_put(cd->owner); 1412 return 0; 1413 } 1414 1415 static ssize_t read_flush(struct file *file, char __user *buf, 1416 size_t count, loff_t *ppos, 1417 struct cache_detail *cd) 1418 { 1419 char tbuf[22]; 1420 unsigned long p = *ppos; 1421 size_t len; 1422 1423 snprintf(tbuf, sizeof(tbuf), "%lu\n", convert_to_wallclock(cd->flush_time)); 1424 len = strlen(tbuf); 1425 if (p >= len) 1426 return 0; 1427 len -= p; 1428 if (len > count) 1429 len = count; 1430 if (copy_to_user(buf, (void*)(tbuf+p), len)) 1431 return -EFAULT; 1432 *ppos += len; 1433 return len; 1434 } 1435 1436 static ssize_t write_flush(struct file *file, const char __user *buf, 1437 size_t count, loff_t *ppos, 1438 struct cache_detail *cd) 1439 { 1440 char tbuf[20]; 1441 char *bp, *ep; 1442 1443 if (*ppos || count > sizeof(tbuf)-1) 1444 return -EINVAL; 1445 if (copy_from_user(tbuf, buf, count)) 1446 return -EFAULT; 1447 tbuf[count] = 0; 1448 simple_strtoul(tbuf, &ep, 0); 1449 if (*ep && *ep != '\n') 1450 return -EINVAL; 1451 1452 bp = tbuf; 1453 cd->flush_time = get_expiry(&bp); 1454 cd->nextcheck = seconds_since_boot(); 1455 cache_flush(); 1456 1457 *ppos += count; 1458 return count; 1459 } 1460 1461 static ssize_t cache_read_procfs(struct file *filp, char __user *buf, 1462 size_t count, loff_t *ppos) 1463 { 1464 struct cache_detail *cd = PDE(file_inode(filp))->data; 1465 1466 return cache_read(filp, buf, count, ppos, cd); 1467 } 1468 1469 static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, 1470 size_t count, loff_t *ppos) 1471 { 1472 struct cache_detail *cd = PDE(file_inode(filp))->data; 1473 1474 return cache_write(filp, buf, count, ppos, cd); 1475 } 1476 1477 static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) 1478 { 1479 struct cache_detail *cd = PDE(file_inode(filp))->data; 1480 1481 return cache_poll(filp, wait, cd); 1482 } 1483 1484 static long cache_ioctl_procfs(struct file *filp, 1485 unsigned int cmd, unsigned long arg) 1486 { 1487 struct inode *inode = file_inode(filp); 1488 struct cache_detail *cd = PDE(inode)->data; 1489 1490 return cache_ioctl(inode, filp, cmd, arg, cd); 1491 } 1492 1493 static int cache_open_procfs(struct inode *inode, struct file *filp) 1494 { 1495 struct cache_detail *cd = PDE(inode)->data; 1496 1497 return cache_open(inode, filp, cd); 1498 } 1499 1500 static int cache_release_procfs(struct inode *inode, struct file *filp) 1501 { 1502 struct cache_detail *cd = PDE(inode)->data; 1503 1504 return cache_release(inode, filp, cd); 1505 } 1506 1507 static const struct file_operations cache_file_operations_procfs = { 1508 .owner = THIS_MODULE, 1509 .llseek = no_llseek, 1510 .read = cache_read_procfs, 1511 .write = cache_write_procfs, 1512 .poll = cache_poll_procfs, 1513 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ 1514 .open = cache_open_procfs, 1515 .release = cache_release_procfs, 1516 }; 1517 1518 static int content_open_procfs(struct inode *inode, struct file *filp) 1519 { 1520 struct cache_detail *cd = PDE(inode)->data; 1521 1522 return content_open(inode, filp, cd); 1523 } 1524 1525 static int content_release_procfs(struct inode *inode, struct file *filp) 1526 { 1527 struct cache_detail *cd = PDE(inode)->data; 1528 1529 return content_release(inode, filp, cd); 1530 } 1531 1532 static const struct file_operations content_file_operations_procfs = { 1533 .open = content_open_procfs, 1534 .read = seq_read, 1535 .llseek = seq_lseek, 1536 .release = content_release_procfs, 1537 }; 1538 1539 static int open_flush_procfs(struct inode *inode, struct file *filp) 1540 { 1541 struct cache_detail *cd = PDE(inode)->data; 1542 1543 return open_flush(inode, filp, cd); 1544 } 1545 1546 static int release_flush_procfs(struct inode *inode, struct file *filp) 1547 { 1548 struct cache_detail *cd = PDE(inode)->data; 1549 1550 return release_flush(inode, filp, cd); 1551 } 1552 1553 static ssize_t read_flush_procfs(struct file *filp, char __user *buf, 1554 size_t count, loff_t *ppos) 1555 { 1556 struct cache_detail *cd = PDE(file_inode(filp))->data; 1557 1558 return read_flush(filp, buf, count, ppos, cd); 1559 } 1560 1561 static ssize_t write_flush_procfs(struct file *filp, 1562 const char __user *buf, 1563 size_t count, loff_t *ppos) 1564 { 1565 struct cache_detail *cd = PDE(file_inode(filp))->data; 1566 1567 return write_flush(filp, buf, count, ppos, cd); 1568 } 1569 1570 static const struct file_operations cache_flush_operations_procfs = { 1571 .open = open_flush_procfs, 1572 .read = read_flush_procfs, 1573 .write = write_flush_procfs, 1574 .release = release_flush_procfs, 1575 .llseek = no_llseek, 1576 }; 1577 1578 static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net) 1579 { 1580 struct sunrpc_net *sn; 1581 1582 if (cd->u.procfs.proc_ent == NULL) 1583 return; 1584 if (cd->u.procfs.flush_ent) 1585 remove_proc_entry("flush", cd->u.procfs.proc_ent); 1586 if (cd->u.procfs.channel_ent) 1587 remove_proc_entry("channel", cd->u.procfs.proc_ent); 1588 if (cd->u.procfs.content_ent) 1589 remove_proc_entry("content", cd->u.procfs.proc_ent); 1590 cd->u.procfs.proc_ent = NULL; 1591 sn = net_generic(net, sunrpc_net_id); 1592 remove_proc_entry(cd->name, sn->proc_net_rpc); 1593 } 1594 1595 #ifdef CONFIG_PROC_FS 1596 static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) 1597 { 1598 struct proc_dir_entry *p; 1599 struct sunrpc_net *sn; 1600 1601 sn = net_generic(net, sunrpc_net_id); 1602 cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc); 1603 if (cd->u.procfs.proc_ent == NULL) 1604 goto out_nomem; 1605 cd->u.procfs.channel_ent = NULL; 1606 cd->u.procfs.content_ent = NULL; 1607 1608 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, 1609 cd->u.procfs.proc_ent, 1610 &cache_flush_operations_procfs, cd); 1611 cd->u.procfs.flush_ent = p; 1612 if (p == NULL) 1613 goto out_nomem; 1614 1615 if (cd->cache_request || cd->cache_parse) { 1616 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, 1617 cd->u.procfs.proc_ent, 1618 &cache_file_operations_procfs, cd); 1619 cd->u.procfs.channel_ent = p; 1620 if (p == NULL) 1621 goto out_nomem; 1622 } 1623 if (cd->cache_show) { 1624 p = proc_create_data("content", S_IFREG|S_IRUSR, 1625 cd->u.procfs.proc_ent, 1626 &content_file_operations_procfs, cd); 1627 cd->u.procfs.content_ent = p; 1628 if (p == NULL) 1629 goto out_nomem; 1630 } 1631 return 0; 1632 out_nomem: 1633 remove_cache_proc_entries(cd, net); 1634 return -ENOMEM; 1635 } 1636 #else /* CONFIG_PROC_FS */ 1637 static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) 1638 { 1639 return 0; 1640 } 1641 #endif 1642 1643 void __init cache_initialize(void) 1644 { 1645 INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean); 1646 } 1647 1648 int cache_register_net(struct cache_detail *cd, struct net *net) 1649 { 1650 int ret; 1651 1652 sunrpc_init_cache_detail(cd); 1653 ret = create_cache_proc_entries(cd, net); 1654 if (ret) 1655 sunrpc_destroy_cache_detail(cd); 1656 return ret; 1657 } 1658 EXPORT_SYMBOL_GPL(cache_register_net); 1659 1660 void cache_unregister_net(struct cache_detail *cd, struct net *net) 1661 { 1662 remove_cache_proc_entries(cd, net); 1663 sunrpc_destroy_cache_detail(cd); 1664 } 1665 EXPORT_SYMBOL_GPL(cache_unregister_net); 1666 1667 struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) 1668 { 1669 struct cache_detail *cd; 1670 1671 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); 1672 if (cd == NULL) 1673 return ERR_PTR(-ENOMEM); 1674 1675 cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *), 1676 GFP_KERNEL); 1677 if (cd->hash_table == NULL) { 1678 kfree(cd); 1679 return ERR_PTR(-ENOMEM); 1680 } 1681 cd->net = net; 1682 return cd; 1683 } 1684 EXPORT_SYMBOL_GPL(cache_create_net); 1685 1686 void cache_destroy_net(struct cache_detail *cd, struct net *net) 1687 { 1688 kfree(cd->hash_table); 1689 kfree(cd); 1690 } 1691 EXPORT_SYMBOL_GPL(cache_destroy_net); 1692 1693 static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, 1694 size_t count, loff_t *ppos) 1695 { 1696 struct cache_detail *cd = RPC_I(file_inode(filp))->private; 1697 1698 return cache_read(filp, buf, count, ppos, cd); 1699 } 1700 1701 static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, 1702 size_t count, loff_t *ppos) 1703 { 1704 struct cache_detail *cd = RPC_I(file_inode(filp))->private; 1705 1706 return cache_write(filp, buf, count, ppos, cd); 1707 } 1708 1709 static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) 1710 { 1711 struct cache_detail *cd = RPC_I(file_inode(filp))->private; 1712 1713 return cache_poll(filp, wait, cd); 1714 } 1715 1716 static long cache_ioctl_pipefs(struct file *filp, 1717 unsigned int cmd, unsigned long arg) 1718 { 1719 struct inode *inode = file_inode(filp); 1720 struct cache_detail *cd = RPC_I(inode)->private; 1721 1722 return cache_ioctl(inode, filp, cmd, arg, cd); 1723 } 1724 1725 static int cache_open_pipefs(struct inode *inode, struct file *filp) 1726 { 1727 struct cache_detail *cd = RPC_I(inode)->private; 1728 1729 return cache_open(inode, filp, cd); 1730 } 1731 1732 static int cache_release_pipefs(struct inode *inode, struct file *filp) 1733 { 1734 struct cache_detail *cd = RPC_I(inode)->private; 1735 1736 return cache_release(inode, filp, cd); 1737 } 1738 1739 const struct file_operations cache_file_operations_pipefs = { 1740 .owner = THIS_MODULE, 1741 .llseek = no_llseek, 1742 .read = cache_read_pipefs, 1743 .write = cache_write_pipefs, 1744 .poll = cache_poll_pipefs, 1745 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ 1746 .open = cache_open_pipefs, 1747 .release = cache_release_pipefs, 1748 }; 1749 1750 static int content_open_pipefs(struct inode *inode, struct file *filp) 1751 { 1752 struct cache_detail *cd = RPC_I(inode)->private; 1753 1754 return content_open(inode, filp, cd); 1755 } 1756 1757 static int content_release_pipefs(struct inode *inode, struct file *filp) 1758 { 1759 struct cache_detail *cd = RPC_I(inode)->private; 1760 1761 return content_release(inode, filp, cd); 1762 } 1763 1764 const struct file_operations content_file_operations_pipefs = { 1765 .open = content_open_pipefs, 1766 .read = seq_read, 1767 .llseek = seq_lseek, 1768 .release = content_release_pipefs, 1769 }; 1770 1771 static int open_flush_pipefs(struct inode *inode, struct file *filp) 1772 { 1773 struct cache_detail *cd = RPC_I(inode)->private; 1774 1775 return open_flush(inode, filp, cd); 1776 } 1777 1778 static int release_flush_pipefs(struct inode *inode, struct file *filp) 1779 { 1780 struct cache_detail *cd = RPC_I(inode)->private; 1781 1782 return release_flush(inode, filp, cd); 1783 } 1784 1785 static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, 1786 size_t count, loff_t *ppos) 1787 { 1788 struct cache_detail *cd = RPC_I(file_inode(filp))->private; 1789 1790 return read_flush(filp, buf, count, ppos, cd); 1791 } 1792 1793 static ssize_t write_flush_pipefs(struct file *filp, 1794 const char __user *buf, 1795 size_t count, loff_t *ppos) 1796 { 1797 struct cache_detail *cd = RPC_I(file_inode(filp))->private; 1798 1799 return write_flush(filp, buf, count, ppos, cd); 1800 } 1801 1802 const struct file_operations cache_flush_operations_pipefs = { 1803 .open = open_flush_pipefs, 1804 .read = read_flush_pipefs, 1805 .write = write_flush_pipefs, 1806 .release = release_flush_pipefs, 1807 .llseek = no_llseek, 1808 }; 1809 1810 int sunrpc_cache_register_pipefs(struct dentry *parent, 1811 const char *name, umode_t umode, 1812 struct cache_detail *cd) 1813 { 1814 struct qstr q; 1815 struct dentry *dir; 1816 int ret = 0; 1817 1818 q.name = name; 1819 q.len = strlen(name); 1820 q.hash = full_name_hash(q.name, q.len); 1821 dir = rpc_create_cache_dir(parent, &q, umode, cd); 1822 if (!IS_ERR(dir)) 1823 cd->u.pipefs.dir = dir; 1824 else 1825 ret = PTR_ERR(dir); 1826 return ret; 1827 } 1828 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); 1829 1830 void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) 1831 { 1832 rpc_remove_cache_dir(cd->u.pipefs.dir); 1833 cd->u.pipefs.dir = NULL; 1834 } 1835 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); 1836 1837