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 -EINVAL; 201 return cd->cache_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 *lp, *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, lp, 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 ssize_t cache_read(struct file *filp, char __user *buf, size_t count, 754 loff_t *ppos, struct cache_detail *cd) 755 { 756 struct cache_reader *rp = filp->private_data; 757 struct cache_request *rq; 758 struct inode *inode = filp->f_path.dentry->d_inode; 759 int err; 760 761 if (count == 0) 762 return 0; 763 764 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent 765 * readers on this file */ 766 again: 767 spin_lock(&queue_lock); 768 /* need to find next request */ 769 while (rp->q.list.next != &cd->queue && 770 list_entry(rp->q.list.next, struct cache_queue, list) 771 ->reader) { 772 struct list_head *next = rp->q.list.next; 773 list_move(&rp->q.list, next); 774 } 775 if (rp->q.list.next == &cd->queue) { 776 spin_unlock(&queue_lock); 777 mutex_unlock(&inode->i_mutex); 778 BUG_ON(rp->offset); 779 return 0; 780 } 781 rq = container_of(rp->q.list.next, struct cache_request, q.list); 782 BUG_ON(rq->q.reader); 783 if (rp->offset == 0) 784 rq->readers++; 785 spin_unlock(&queue_lock); 786 787 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { 788 err = -EAGAIN; 789 spin_lock(&queue_lock); 790 list_move(&rp->q.list, &rq->q.list); 791 spin_unlock(&queue_lock); 792 } else { 793 if (rp->offset + count > rq->len) 794 count = rq->len - rp->offset; 795 err = -EFAULT; 796 if (copy_to_user(buf, rq->buf + rp->offset, count)) 797 goto out; 798 rp->offset += count; 799 if (rp->offset >= rq->len) { 800 rp->offset = 0; 801 spin_lock(&queue_lock); 802 list_move(&rp->q.list, &rq->q.list); 803 spin_unlock(&queue_lock); 804 } 805 err = 0; 806 } 807 out: 808 if (rp->offset == 0) { 809 /* need to release rq */ 810 spin_lock(&queue_lock); 811 rq->readers--; 812 if (rq->readers == 0 && 813 !test_bit(CACHE_PENDING, &rq->item->flags)) { 814 list_del(&rq->q.list); 815 spin_unlock(&queue_lock); 816 cache_put(rq->item, cd); 817 kfree(rq->buf); 818 kfree(rq); 819 } else 820 spin_unlock(&queue_lock); 821 } 822 if (err == -EAGAIN) 823 goto again; 824 mutex_unlock(&inode->i_mutex); 825 return err ? err : count; 826 } 827 828 static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, 829 size_t count, struct cache_detail *cd) 830 { 831 ssize_t ret; 832 833 if (copy_from_user(kaddr, buf, count)) 834 return -EFAULT; 835 kaddr[count] = '\0'; 836 ret = cd->cache_parse(cd, kaddr, count); 837 if (!ret) 838 ret = count; 839 return ret; 840 } 841 842 static ssize_t cache_slow_downcall(const char __user *buf, 843 size_t count, struct cache_detail *cd) 844 { 845 static char write_buf[8192]; /* protected by queue_io_mutex */ 846 ssize_t ret = -EINVAL; 847 848 if (count >= sizeof(write_buf)) 849 goto out; 850 mutex_lock(&queue_io_mutex); 851 ret = cache_do_downcall(write_buf, buf, count, cd); 852 mutex_unlock(&queue_io_mutex); 853 out: 854 return ret; 855 } 856 857 static ssize_t cache_downcall(struct address_space *mapping, 858 const char __user *buf, 859 size_t count, struct cache_detail *cd) 860 { 861 struct page *page; 862 char *kaddr; 863 ssize_t ret = -ENOMEM; 864 865 if (count >= PAGE_CACHE_SIZE) 866 goto out_slow; 867 868 page = find_or_create_page(mapping, 0, GFP_KERNEL); 869 if (!page) 870 goto out_slow; 871 872 kaddr = kmap(page); 873 ret = cache_do_downcall(kaddr, buf, count, cd); 874 kunmap(page); 875 unlock_page(page); 876 page_cache_release(page); 877 return ret; 878 out_slow: 879 return cache_slow_downcall(buf, count, cd); 880 } 881 882 static ssize_t cache_write(struct file *filp, const char __user *buf, 883 size_t count, loff_t *ppos, 884 struct cache_detail *cd) 885 { 886 struct address_space *mapping = filp->f_mapping; 887 struct inode *inode = filp->f_path.dentry->d_inode; 888 ssize_t ret = -EINVAL; 889 890 if (!cd->cache_parse) 891 goto out; 892 893 mutex_lock(&inode->i_mutex); 894 ret = cache_downcall(mapping, buf, count, cd); 895 mutex_unlock(&inode->i_mutex); 896 out: 897 return ret; 898 } 899 900 static DECLARE_WAIT_QUEUE_HEAD(queue_wait); 901 902 static unsigned int cache_poll(struct file *filp, poll_table *wait, 903 struct cache_detail *cd) 904 { 905 unsigned int mask; 906 struct cache_reader *rp = filp->private_data; 907 struct cache_queue *cq; 908 909 poll_wait(filp, &queue_wait, wait); 910 911 /* alway allow write */ 912 mask = POLL_OUT | POLLWRNORM; 913 914 if (!rp) 915 return mask; 916 917 spin_lock(&queue_lock); 918 919 for (cq= &rp->q; &cq->list != &cd->queue; 920 cq = list_entry(cq->list.next, struct cache_queue, list)) 921 if (!cq->reader) { 922 mask |= POLLIN | POLLRDNORM; 923 break; 924 } 925 spin_unlock(&queue_lock); 926 return mask; 927 } 928 929 static int cache_ioctl(struct inode *ino, struct file *filp, 930 unsigned int cmd, unsigned long arg, 931 struct cache_detail *cd) 932 { 933 int len = 0; 934 struct cache_reader *rp = filp->private_data; 935 struct cache_queue *cq; 936 937 if (cmd != FIONREAD || !rp) 938 return -EINVAL; 939 940 spin_lock(&queue_lock); 941 942 /* only find the length remaining in current request, 943 * or the length of the next request 944 */ 945 for (cq= &rp->q; &cq->list != &cd->queue; 946 cq = list_entry(cq->list.next, struct cache_queue, list)) 947 if (!cq->reader) { 948 struct cache_request *cr = 949 container_of(cq, struct cache_request, q); 950 len = cr->len - rp->offset; 951 break; 952 } 953 spin_unlock(&queue_lock); 954 955 return put_user(len, (int __user *)arg); 956 } 957 958 static int cache_open(struct inode *inode, struct file *filp, 959 struct cache_detail *cd) 960 { 961 struct cache_reader *rp = NULL; 962 963 if (!cd || !try_module_get(cd->owner)) 964 return -EACCES; 965 nonseekable_open(inode, filp); 966 if (filp->f_mode & FMODE_READ) { 967 rp = kmalloc(sizeof(*rp), GFP_KERNEL); 968 if (!rp) 969 return -ENOMEM; 970 rp->offset = 0; 971 rp->q.reader = 1; 972 atomic_inc(&cd->readers); 973 spin_lock(&queue_lock); 974 list_add(&rp->q.list, &cd->queue); 975 spin_unlock(&queue_lock); 976 } 977 filp->private_data = rp; 978 return 0; 979 } 980 981 static int cache_release(struct inode *inode, struct file *filp, 982 struct cache_detail *cd) 983 { 984 struct cache_reader *rp = filp->private_data; 985 986 if (rp) { 987 spin_lock(&queue_lock); 988 if (rp->offset) { 989 struct cache_queue *cq; 990 for (cq= &rp->q; &cq->list != &cd->queue; 991 cq = list_entry(cq->list.next, struct cache_queue, list)) 992 if (!cq->reader) { 993 container_of(cq, struct cache_request, q) 994 ->readers--; 995 break; 996 } 997 rp->offset = 0; 998 } 999 list_del(&rp->q.list); 1000 spin_unlock(&queue_lock); 1001 1002 filp->private_data = NULL; 1003 kfree(rp); 1004 1005 cd->last_close = seconds_since_boot(); 1006 atomic_dec(&cd->readers); 1007 } 1008 module_put(cd->owner); 1009 return 0; 1010 } 1011 1012 1013 1014 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) 1015 { 1016 struct cache_queue *cq; 1017 spin_lock(&queue_lock); 1018 list_for_each_entry(cq, &detail->queue, list) 1019 if (!cq->reader) { 1020 struct cache_request *cr = container_of(cq, struct cache_request, q); 1021 if (cr->item != ch) 1022 continue; 1023 if (cr->readers != 0) 1024 continue; 1025 list_del(&cr->q.list); 1026 spin_unlock(&queue_lock); 1027 cache_put(cr->item, detail); 1028 kfree(cr->buf); 1029 kfree(cr); 1030 return; 1031 } 1032 spin_unlock(&queue_lock); 1033 } 1034 1035 /* 1036 * Support routines for text-based upcalls. 1037 * Fields are separated by spaces. 1038 * Fields are either mangled to quote space tab newline slosh with slosh 1039 * or a hexified with a leading \x 1040 * Record is terminated with newline. 1041 * 1042 */ 1043 1044 void qword_add(char **bpp, int *lp, char *str) 1045 { 1046 char *bp = *bpp; 1047 int len = *lp; 1048 char c; 1049 1050 if (len < 0) return; 1051 1052 while ((c=*str++) && len) 1053 switch(c) { 1054 case ' ': 1055 case '\t': 1056 case '\n': 1057 case '\\': 1058 if (len >= 4) { 1059 *bp++ = '\\'; 1060 *bp++ = '0' + ((c & 0300)>>6); 1061 *bp++ = '0' + ((c & 0070)>>3); 1062 *bp++ = '0' + ((c & 0007)>>0); 1063 } 1064 len -= 4; 1065 break; 1066 default: 1067 *bp++ = c; 1068 len--; 1069 } 1070 if (c || len <1) len = -1; 1071 else { 1072 *bp++ = ' '; 1073 len--; 1074 } 1075 *bpp = bp; 1076 *lp = len; 1077 } 1078 EXPORT_SYMBOL_GPL(qword_add); 1079 1080 void qword_addhex(char **bpp, int *lp, char *buf, int blen) 1081 { 1082 char *bp = *bpp; 1083 int len = *lp; 1084 1085 if (len < 0) return; 1086 1087 if (len > 2) { 1088 *bp++ = '\\'; 1089 *bp++ = 'x'; 1090 len -= 2; 1091 while (blen && len >= 2) { 1092 unsigned char c = *buf++; 1093 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 1094 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 1095 len -= 2; 1096 blen--; 1097 } 1098 } 1099 if (blen || len<1) len = -1; 1100 else { 1101 *bp++ = ' '; 1102 len--; 1103 } 1104 *bpp = bp; 1105 *lp = len; 1106 } 1107 EXPORT_SYMBOL_GPL(qword_addhex); 1108 1109 static void warn_no_listener(struct cache_detail *detail) 1110 { 1111 if (detail->last_warn != detail->last_close) { 1112 detail->last_warn = detail->last_close; 1113 if (detail->warn_no_listener) 1114 detail->warn_no_listener(detail, detail->last_close != 0); 1115 } 1116 } 1117 1118 static bool cache_listeners_exist(struct cache_detail *detail) 1119 { 1120 if (atomic_read(&detail->readers)) 1121 return true; 1122 if (detail->last_close == 0) 1123 /* This cache was never opened */ 1124 return false; 1125 if (detail->last_close < seconds_since_boot() - 30) 1126 /* 1127 * We allow for the possibility that someone might 1128 * restart a userspace daemon without restarting the 1129 * server; but after 30 seconds, we give up. 1130 */ 1131 return false; 1132 return true; 1133 } 1134 1135 /* 1136 * register an upcall request to user-space and queue it up for read() by the 1137 * upcall daemon. 1138 * 1139 * Each request is at most one page long. 1140 */ 1141 int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, 1142 void (*cache_request)(struct cache_detail *, 1143 struct cache_head *, 1144 char **, 1145 int *)) 1146 { 1147 1148 char *buf; 1149 struct cache_request *crq; 1150 char *bp; 1151 int len; 1152 1153 if (!cache_listeners_exist(detail)) { 1154 warn_no_listener(detail); 1155 return -EINVAL; 1156 } 1157 1158 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 1159 if (!buf) 1160 return -EAGAIN; 1161 1162 crq = kmalloc(sizeof (*crq), GFP_KERNEL); 1163 if (!crq) { 1164 kfree(buf); 1165 return -EAGAIN; 1166 } 1167 1168 bp = buf; len = PAGE_SIZE; 1169 1170 cache_request(detail, h, &bp, &len); 1171 1172 if (len < 0) { 1173 kfree(buf); 1174 kfree(crq); 1175 return -EAGAIN; 1176 } 1177 crq->q.reader = 0; 1178 crq->item = cache_get(h); 1179 crq->buf = buf; 1180 crq->len = PAGE_SIZE - len; 1181 crq->readers = 0; 1182 spin_lock(&queue_lock); 1183 list_add_tail(&crq->q.list, &detail->queue); 1184 spin_unlock(&queue_lock); 1185 wake_up(&queue_wait); 1186 return 0; 1187 } 1188 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); 1189 1190 /* 1191 * parse a message from user-space and pass it 1192 * to an appropriate cache 1193 * Messages are, like requests, separated into fields by 1194 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal 1195 * 1196 * Message is 1197 * reply cachename expiry key ... content.... 1198 * 1199 * key and content are both parsed by cache 1200 */ 1201 1202 #define isodigit(c) (isdigit(c) && c <= '7') 1203 int qword_get(char **bpp, char *dest, int bufsize) 1204 { 1205 /* return bytes copied, or -1 on error */ 1206 char *bp = *bpp; 1207 int len = 0; 1208 1209 while (*bp == ' ') bp++; 1210 1211 if (bp[0] == '\\' && bp[1] == 'x') { 1212 /* HEX STRING */ 1213 bp += 2; 1214 while (len < bufsize) { 1215 int h, l; 1216 1217 h = hex_to_bin(bp[0]); 1218 if (h < 0) 1219 break; 1220 1221 l = hex_to_bin(bp[1]); 1222 if (l < 0) 1223 break; 1224 1225 *dest++ = (h << 4) | l; 1226 bp += 2; 1227 len++; 1228 } 1229 } else { 1230 /* text with \nnn octal quoting */ 1231 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { 1232 if (*bp == '\\' && 1233 isodigit(bp[1]) && (bp[1] <= '3') && 1234 isodigit(bp[2]) && 1235 isodigit(bp[3])) { 1236 int byte = (*++bp -'0'); 1237 bp++; 1238 byte = (byte << 3) | (*bp++ - '0'); 1239 byte = (byte << 3) | (*bp++ - '0'); 1240 *dest++ = byte; 1241 len++; 1242 } else { 1243 *dest++ = *bp++; 1244 len++; 1245 } 1246 } 1247 } 1248 1249 if (*bp != ' ' && *bp != '\n' && *bp != '\0') 1250 return -1; 1251 while (*bp == ' ') bp++; 1252 *bpp = bp; 1253 *dest = '\0'; 1254 return len; 1255 } 1256 EXPORT_SYMBOL_GPL(qword_get); 1257 1258 1259 /* 1260 * support /proc/sunrpc/cache/$CACHENAME/content 1261 * as a seqfile. 1262 * We call ->cache_show passing NULL for the item to 1263 * get a header, then pass each real item in the cache 1264 */ 1265 1266 struct handle { 1267 struct cache_detail *cd; 1268 }; 1269 1270 static void *c_start(struct seq_file *m, loff_t *pos) 1271 __acquires(cd->hash_lock) 1272 { 1273 loff_t n = *pos; 1274 unsigned hash, entry; 1275 struct cache_head *ch; 1276 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1277 1278 1279 read_lock(&cd->hash_lock); 1280 if (!n--) 1281 return SEQ_START_TOKEN; 1282 hash = n >> 32; 1283 entry = n & ((1LL<<32) - 1); 1284 1285 for (ch=cd->hash_table[hash]; ch; ch=ch->next) 1286 if (!entry--) 1287 return ch; 1288 n &= ~((1LL<<32) - 1); 1289 do { 1290 hash++; 1291 n += 1LL<<32; 1292 } while(hash < cd->hash_size && 1293 cd->hash_table[hash]==NULL); 1294 if (hash >= cd->hash_size) 1295 return NULL; 1296 *pos = n+1; 1297 return cd->hash_table[hash]; 1298 } 1299 1300 static void *c_next(struct seq_file *m, void *p, loff_t *pos) 1301 { 1302 struct cache_head *ch = p; 1303 int hash = (*pos >> 32); 1304 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1305 1306 if (p == SEQ_START_TOKEN) 1307 hash = 0; 1308 else if (ch->next == NULL) { 1309 hash++; 1310 *pos += 1LL<<32; 1311 } else { 1312 ++*pos; 1313 return ch->next; 1314 } 1315 *pos &= ~((1LL<<32) - 1); 1316 while (hash < cd->hash_size && 1317 cd->hash_table[hash] == NULL) { 1318 hash++; 1319 *pos += 1LL<<32; 1320 } 1321 if (hash >= cd->hash_size) 1322 return NULL; 1323 ++*pos; 1324 return cd->hash_table[hash]; 1325 } 1326 1327 static void c_stop(struct seq_file *m, void *p) 1328 __releases(cd->hash_lock) 1329 { 1330 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1331 read_unlock(&cd->hash_lock); 1332 } 1333 1334 static int c_show(struct seq_file *m, void *p) 1335 { 1336 struct cache_head *cp = p; 1337 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1338 1339 if (p == SEQ_START_TOKEN) 1340 return cd->cache_show(m, cd, NULL); 1341 1342 ifdebug(CACHE) 1343 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", 1344 convert_to_wallclock(cp->expiry_time), 1345 atomic_read(&cp->ref.refcount), cp->flags); 1346 cache_get(cp); 1347 if (cache_check(cd, cp, NULL)) 1348 /* cache_check does a cache_put on failure */ 1349 seq_printf(m, "# "); 1350 else 1351 cache_put(cp, cd); 1352 1353 return cd->cache_show(m, cd, cp); 1354 } 1355 1356 static const struct seq_operations cache_content_op = { 1357 .start = c_start, 1358 .next = c_next, 1359 .stop = c_stop, 1360 .show = c_show, 1361 }; 1362 1363 static int content_open(struct inode *inode, struct file *file, 1364 struct cache_detail *cd) 1365 { 1366 struct handle *han; 1367 1368 if (!cd || !try_module_get(cd->owner)) 1369 return -EACCES; 1370 han = __seq_open_private(file, &cache_content_op, sizeof(*han)); 1371 if (han == NULL) { 1372 module_put(cd->owner); 1373 return -ENOMEM; 1374 } 1375 1376 han->cd = cd; 1377 return 0; 1378 } 1379 1380 static int content_release(struct inode *inode, struct file *file, 1381 struct cache_detail *cd) 1382 { 1383 int ret = seq_release_private(inode, file); 1384 module_put(cd->owner); 1385 return ret; 1386 } 1387 1388 static int open_flush(struct inode *inode, struct file *file, 1389 struct cache_detail *cd) 1390 { 1391 if (!cd || !try_module_get(cd->owner)) 1392 return -EACCES; 1393 return nonseekable_open(inode, file); 1394 } 1395 1396 static int release_flush(struct inode *inode, struct file *file, 1397 struct cache_detail *cd) 1398 { 1399 module_put(cd->owner); 1400 return 0; 1401 } 1402 1403 static ssize_t read_flush(struct file *file, char __user *buf, 1404 size_t count, loff_t *ppos, 1405 struct cache_detail *cd) 1406 { 1407 char tbuf[20]; 1408 unsigned long p = *ppos; 1409 size_t len; 1410 1411 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time)); 1412 len = strlen(tbuf); 1413 if (p >= len) 1414 return 0; 1415 len -= p; 1416 if (len > count) 1417 len = count; 1418 if (copy_to_user(buf, (void*)(tbuf+p), len)) 1419 return -EFAULT; 1420 *ppos += len; 1421 return len; 1422 } 1423 1424 static ssize_t write_flush(struct file *file, const char __user *buf, 1425 size_t count, loff_t *ppos, 1426 struct cache_detail *cd) 1427 { 1428 char tbuf[20]; 1429 char *bp, *ep; 1430 1431 if (*ppos || count > sizeof(tbuf)-1) 1432 return -EINVAL; 1433 if (copy_from_user(tbuf, buf, count)) 1434 return -EFAULT; 1435 tbuf[count] = 0; 1436 simple_strtoul(tbuf, &ep, 0); 1437 if (*ep && *ep != '\n') 1438 return -EINVAL; 1439 1440 bp = tbuf; 1441 cd->flush_time = get_expiry(&bp); 1442 cd->nextcheck = seconds_since_boot(); 1443 cache_flush(); 1444 1445 *ppos += count; 1446 return count; 1447 } 1448 1449 static ssize_t cache_read_procfs(struct file *filp, char __user *buf, 1450 size_t count, loff_t *ppos) 1451 { 1452 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1453 1454 return cache_read(filp, buf, count, ppos, cd); 1455 } 1456 1457 static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, 1458 size_t count, loff_t *ppos) 1459 { 1460 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1461 1462 return cache_write(filp, buf, count, ppos, cd); 1463 } 1464 1465 static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) 1466 { 1467 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1468 1469 return cache_poll(filp, wait, cd); 1470 } 1471 1472 static long cache_ioctl_procfs(struct file *filp, 1473 unsigned int cmd, unsigned long arg) 1474 { 1475 struct inode *inode = filp->f_path.dentry->d_inode; 1476 struct cache_detail *cd = PDE(inode)->data; 1477 1478 return cache_ioctl(inode, filp, cmd, arg, cd); 1479 } 1480 1481 static int cache_open_procfs(struct inode *inode, struct file *filp) 1482 { 1483 struct cache_detail *cd = PDE(inode)->data; 1484 1485 return cache_open(inode, filp, cd); 1486 } 1487 1488 static int cache_release_procfs(struct inode *inode, struct file *filp) 1489 { 1490 struct cache_detail *cd = PDE(inode)->data; 1491 1492 return cache_release(inode, filp, cd); 1493 } 1494 1495 static const struct file_operations cache_file_operations_procfs = { 1496 .owner = THIS_MODULE, 1497 .llseek = no_llseek, 1498 .read = cache_read_procfs, 1499 .write = cache_write_procfs, 1500 .poll = cache_poll_procfs, 1501 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ 1502 .open = cache_open_procfs, 1503 .release = cache_release_procfs, 1504 }; 1505 1506 static int content_open_procfs(struct inode *inode, struct file *filp) 1507 { 1508 struct cache_detail *cd = PDE(inode)->data; 1509 1510 return content_open(inode, filp, cd); 1511 } 1512 1513 static int content_release_procfs(struct inode *inode, struct file *filp) 1514 { 1515 struct cache_detail *cd = PDE(inode)->data; 1516 1517 return content_release(inode, filp, cd); 1518 } 1519 1520 static const struct file_operations content_file_operations_procfs = { 1521 .open = content_open_procfs, 1522 .read = seq_read, 1523 .llseek = seq_lseek, 1524 .release = content_release_procfs, 1525 }; 1526 1527 static int open_flush_procfs(struct inode *inode, struct file *filp) 1528 { 1529 struct cache_detail *cd = PDE(inode)->data; 1530 1531 return open_flush(inode, filp, cd); 1532 } 1533 1534 static int release_flush_procfs(struct inode *inode, struct file *filp) 1535 { 1536 struct cache_detail *cd = PDE(inode)->data; 1537 1538 return release_flush(inode, filp, cd); 1539 } 1540 1541 static ssize_t read_flush_procfs(struct file *filp, char __user *buf, 1542 size_t count, loff_t *ppos) 1543 { 1544 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1545 1546 return read_flush(filp, buf, count, ppos, cd); 1547 } 1548 1549 static ssize_t write_flush_procfs(struct file *filp, 1550 const char __user *buf, 1551 size_t count, loff_t *ppos) 1552 { 1553 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1554 1555 return write_flush(filp, buf, count, ppos, cd); 1556 } 1557 1558 static const struct file_operations cache_flush_operations_procfs = { 1559 .open = open_flush_procfs, 1560 .read = read_flush_procfs, 1561 .write = write_flush_procfs, 1562 .release = release_flush_procfs, 1563 .llseek = no_llseek, 1564 }; 1565 1566 static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net) 1567 { 1568 struct sunrpc_net *sn; 1569 1570 if (cd->u.procfs.proc_ent == NULL) 1571 return; 1572 if (cd->u.procfs.flush_ent) 1573 remove_proc_entry("flush", cd->u.procfs.proc_ent); 1574 if (cd->u.procfs.channel_ent) 1575 remove_proc_entry("channel", cd->u.procfs.proc_ent); 1576 if (cd->u.procfs.content_ent) 1577 remove_proc_entry("content", cd->u.procfs.proc_ent); 1578 cd->u.procfs.proc_ent = NULL; 1579 sn = net_generic(net, sunrpc_net_id); 1580 remove_proc_entry(cd->name, sn->proc_net_rpc); 1581 } 1582 1583 #ifdef CONFIG_PROC_FS 1584 static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) 1585 { 1586 struct proc_dir_entry *p; 1587 struct sunrpc_net *sn; 1588 1589 sn = net_generic(net, sunrpc_net_id); 1590 cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc); 1591 if (cd->u.procfs.proc_ent == NULL) 1592 goto out_nomem; 1593 cd->u.procfs.channel_ent = NULL; 1594 cd->u.procfs.content_ent = NULL; 1595 1596 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, 1597 cd->u.procfs.proc_ent, 1598 &cache_flush_operations_procfs, cd); 1599 cd->u.procfs.flush_ent = p; 1600 if (p == NULL) 1601 goto out_nomem; 1602 1603 if (cd->cache_upcall || cd->cache_parse) { 1604 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, 1605 cd->u.procfs.proc_ent, 1606 &cache_file_operations_procfs, cd); 1607 cd->u.procfs.channel_ent = p; 1608 if (p == NULL) 1609 goto out_nomem; 1610 } 1611 if (cd->cache_show) { 1612 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, 1613 cd->u.procfs.proc_ent, 1614 &content_file_operations_procfs, cd); 1615 cd->u.procfs.content_ent = p; 1616 if (p == NULL) 1617 goto out_nomem; 1618 } 1619 return 0; 1620 out_nomem: 1621 remove_cache_proc_entries(cd, net); 1622 return -ENOMEM; 1623 } 1624 #else /* CONFIG_PROC_FS */ 1625 static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) 1626 { 1627 return 0; 1628 } 1629 #endif 1630 1631 void __init cache_initialize(void) 1632 { 1633 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean); 1634 } 1635 1636 int cache_register_net(struct cache_detail *cd, struct net *net) 1637 { 1638 int ret; 1639 1640 sunrpc_init_cache_detail(cd); 1641 ret = create_cache_proc_entries(cd, net); 1642 if (ret) 1643 sunrpc_destroy_cache_detail(cd); 1644 return ret; 1645 } 1646 EXPORT_SYMBOL_GPL(cache_register_net); 1647 1648 void cache_unregister_net(struct cache_detail *cd, struct net *net) 1649 { 1650 remove_cache_proc_entries(cd, net); 1651 sunrpc_destroy_cache_detail(cd); 1652 } 1653 EXPORT_SYMBOL_GPL(cache_unregister_net); 1654 1655 struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) 1656 { 1657 struct cache_detail *cd; 1658 1659 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); 1660 if (cd == NULL) 1661 return ERR_PTR(-ENOMEM); 1662 1663 cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *), 1664 GFP_KERNEL); 1665 if (cd->hash_table == NULL) { 1666 kfree(cd); 1667 return ERR_PTR(-ENOMEM); 1668 } 1669 cd->net = net; 1670 return cd; 1671 } 1672 EXPORT_SYMBOL_GPL(cache_create_net); 1673 1674 void cache_destroy_net(struct cache_detail *cd, struct net *net) 1675 { 1676 kfree(cd->hash_table); 1677 kfree(cd); 1678 } 1679 EXPORT_SYMBOL_GPL(cache_destroy_net); 1680 1681 static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, 1682 size_t count, loff_t *ppos) 1683 { 1684 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1685 1686 return cache_read(filp, buf, count, ppos, cd); 1687 } 1688 1689 static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, 1690 size_t count, loff_t *ppos) 1691 { 1692 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1693 1694 return cache_write(filp, buf, count, ppos, cd); 1695 } 1696 1697 static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) 1698 { 1699 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1700 1701 return cache_poll(filp, wait, cd); 1702 } 1703 1704 static long cache_ioctl_pipefs(struct file *filp, 1705 unsigned int cmd, unsigned long arg) 1706 { 1707 struct inode *inode = filp->f_dentry->d_inode; 1708 struct cache_detail *cd = RPC_I(inode)->private; 1709 1710 return cache_ioctl(inode, filp, cmd, arg, cd); 1711 } 1712 1713 static int cache_open_pipefs(struct inode *inode, struct file *filp) 1714 { 1715 struct cache_detail *cd = RPC_I(inode)->private; 1716 1717 return cache_open(inode, filp, cd); 1718 } 1719 1720 static int cache_release_pipefs(struct inode *inode, struct file *filp) 1721 { 1722 struct cache_detail *cd = RPC_I(inode)->private; 1723 1724 return cache_release(inode, filp, cd); 1725 } 1726 1727 const struct file_operations cache_file_operations_pipefs = { 1728 .owner = THIS_MODULE, 1729 .llseek = no_llseek, 1730 .read = cache_read_pipefs, 1731 .write = cache_write_pipefs, 1732 .poll = cache_poll_pipefs, 1733 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ 1734 .open = cache_open_pipefs, 1735 .release = cache_release_pipefs, 1736 }; 1737 1738 static int content_open_pipefs(struct inode *inode, struct file *filp) 1739 { 1740 struct cache_detail *cd = RPC_I(inode)->private; 1741 1742 return content_open(inode, filp, cd); 1743 } 1744 1745 static int content_release_pipefs(struct inode *inode, struct file *filp) 1746 { 1747 struct cache_detail *cd = RPC_I(inode)->private; 1748 1749 return content_release(inode, filp, cd); 1750 } 1751 1752 const struct file_operations content_file_operations_pipefs = { 1753 .open = content_open_pipefs, 1754 .read = seq_read, 1755 .llseek = seq_lseek, 1756 .release = content_release_pipefs, 1757 }; 1758 1759 static int open_flush_pipefs(struct inode *inode, struct file *filp) 1760 { 1761 struct cache_detail *cd = RPC_I(inode)->private; 1762 1763 return open_flush(inode, filp, cd); 1764 } 1765 1766 static int release_flush_pipefs(struct inode *inode, struct file *filp) 1767 { 1768 struct cache_detail *cd = RPC_I(inode)->private; 1769 1770 return release_flush(inode, filp, cd); 1771 } 1772 1773 static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, 1774 size_t count, loff_t *ppos) 1775 { 1776 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1777 1778 return read_flush(filp, buf, count, ppos, cd); 1779 } 1780 1781 static ssize_t write_flush_pipefs(struct file *filp, 1782 const char __user *buf, 1783 size_t count, loff_t *ppos) 1784 { 1785 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1786 1787 return write_flush(filp, buf, count, ppos, cd); 1788 } 1789 1790 const struct file_operations cache_flush_operations_pipefs = { 1791 .open = open_flush_pipefs, 1792 .read = read_flush_pipefs, 1793 .write = write_flush_pipefs, 1794 .release = release_flush_pipefs, 1795 .llseek = no_llseek, 1796 }; 1797 1798 int sunrpc_cache_register_pipefs(struct dentry *parent, 1799 const char *name, umode_t umode, 1800 struct cache_detail *cd) 1801 { 1802 struct qstr q; 1803 struct dentry *dir; 1804 int ret = 0; 1805 1806 q.name = name; 1807 q.len = strlen(name); 1808 q.hash = full_name_hash(q.name, q.len); 1809 dir = rpc_create_cache_dir(parent, &q, umode, cd); 1810 if (!IS_ERR(dir)) 1811 cd->u.pipefs.dir = dir; 1812 else 1813 ret = PTR_ERR(dir); 1814 return ret; 1815 } 1816 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); 1817 1818 void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) 1819 { 1820 rpc_remove_cache_dir(cd->u.pipefs.dir); 1821 cd->u.pipefs.dir = NULL; 1822 } 1823 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); 1824 1825