cache.c revision 06497524589f2a7717da33969d541674e0a27da6
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 <linux/smp_lock.h> 32#include <asm/ioctls.h> 33#include <linux/sunrpc/types.h> 34#include <linux/sunrpc/cache.h> 35#include <linux/sunrpc/stats.h> 36#include <linux/sunrpc/rpc_pipe_fs.h> 37 38#define RPCDBG_FACILITY RPCDBG_CACHE 39 40static int cache_defer_req(struct cache_req *req, struct cache_head *item); 41static void cache_revisit_request(struct cache_head *item); 42 43static 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 53static 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 59struct 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} 122EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); 123 124 125static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); 126 127static 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 set_bit(CACHE_VALID, &head->flags); 132} 133 134static void cache_fresh_unlocked(struct cache_head *head, 135 struct cache_detail *detail) 136{ 137 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { 138 cache_revisit_request(head); 139 cache_dequeue(detail, head); 140 } 141} 142 143struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 144 struct cache_head *new, struct cache_head *old, int hash) 145{ 146 /* The 'old' entry is to be replaced by 'new'. 147 * If 'old' is not VALID, we update it directly, 148 * otherwise we need to replace it 149 */ 150 struct cache_head **head; 151 struct cache_head *tmp; 152 153 if (!test_bit(CACHE_VALID, &old->flags)) { 154 write_lock(&detail->hash_lock); 155 if (!test_bit(CACHE_VALID, &old->flags)) { 156 if (test_bit(CACHE_NEGATIVE, &new->flags)) 157 set_bit(CACHE_NEGATIVE, &old->flags); 158 else 159 detail->update(old, new); 160 cache_fresh_locked(old, new->expiry_time); 161 write_unlock(&detail->hash_lock); 162 cache_fresh_unlocked(old, detail); 163 return old; 164 } 165 write_unlock(&detail->hash_lock); 166 } 167 /* We need to insert a new entry */ 168 tmp = detail->alloc(); 169 if (!tmp) { 170 cache_put(old, detail); 171 return NULL; 172 } 173 cache_init(tmp); 174 detail->init(tmp, old); 175 head = &detail->hash_table[hash]; 176 177 write_lock(&detail->hash_lock); 178 if (test_bit(CACHE_NEGATIVE, &new->flags)) 179 set_bit(CACHE_NEGATIVE, &tmp->flags); 180 else 181 detail->update(tmp, new); 182 tmp->next = *head; 183 *head = tmp; 184 detail->entries++; 185 cache_get(tmp); 186 cache_fresh_locked(tmp, new->expiry_time); 187 cache_fresh_locked(old, 0); 188 write_unlock(&detail->hash_lock); 189 cache_fresh_unlocked(tmp, detail); 190 cache_fresh_unlocked(old, detail); 191 cache_put(old, detail); 192 return tmp; 193} 194EXPORT_SYMBOL_GPL(sunrpc_cache_update); 195 196static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) 197{ 198 if (!cd->cache_upcall) 199 return -EINVAL; 200 return cd->cache_upcall(cd, h); 201} 202 203static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h) 204{ 205 if (!test_bit(CACHE_VALID, &h->flags)) 206 return -EAGAIN; 207 else { 208 /* entry is valid */ 209 if (test_bit(CACHE_NEGATIVE, &h->flags)) 210 return -ENOENT; 211 else 212 return 0; 213 } 214} 215 216/* 217 * This is the generic cache management routine for all 218 * the authentication caches. 219 * It checks the currency of a cache item and will (later) 220 * initiate an upcall to fill it if needed. 221 * 222 * 223 * Returns 0 if the cache_head can be used, or cache_puts it and returns 224 * -EAGAIN if upcall is pending and request has been queued 225 * -ETIMEDOUT if upcall failed or request could not be queue or 226 * upcall completed but item is still invalid (implying that 227 * the cache item has been replaced with a newer one). 228 * -ENOENT if cache entry was negative 229 */ 230int cache_check(struct cache_detail *detail, 231 struct cache_head *h, struct cache_req *rqstp) 232{ 233 int rv; 234 long refresh_age, age; 235 236 /* First decide return status as best we can */ 237 rv = cache_is_valid(detail, h); 238 239 /* now see if we want to start an upcall */ 240 refresh_age = (h->expiry_time - h->last_refresh); 241 age = seconds_since_boot() - h->last_refresh; 242 243 if (rqstp == NULL) { 244 if (rv == -EAGAIN) 245 rv = -ENOENT; 246 } else if (rv == -EAGAIN || age > refresh_age/2) { 247 dprintk("RPC: Want update, refage=%ld, age=%ld\n", 248 refresh_age, age); 249 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { 250 switch (cache_make_upcall(detail, h)) { 251 case -EINVAL: 252 clear_bit(CACHE_PENDING, &h->flags); 253 cache_revisit_request(h); 254 if (rv == -EAGAIN) { 255 set_bit(CACHE_NEGATIVE, &h->flags); 256 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY); 257 cache_fresh_unlocked(h, detail); 258 rv = -ENOENT; 259 } 260 break; 261 262 case -EAGAIN: 263 clear_bit(CACHE_PENDING, &h->flags); 264 cache_revisit_request(h); 265 break; 266 } 267 } 268 } 269 270 if (rv == -EAGAIN) { 271 if (cache_defer_req(rqstp, h) < 0) { 272 /* Request is not deferred */ 273 rv = cache_is_valid(detail, h); 274 if (rv == -EAGAIN) 275 rv = -ETIMEDOUT; 276 } 277 } 278 if (rv) 279 cache_put(h, detail); 280 return rv; 281} 282EXPORT_SYMBOL_GPL(cache_check); 283 284/* 285 * caches need to be periodically cleaned. 286 * For this we maintain a list of cache_detail and 287 * a current pointer into that list and into the table 288 * for that entry. 289 * 290 * Each time clean_cache is called it finds the next non-empty entry 291 * in the current table and walks the list in that entry 292 * looking for entries that can be removed. 293 * 294 * An entry gets removed if: 295 * - The expiry is before current time 296 * - The last_refresh time is before the flush_time for that cache 297 * 298 * later we might drop old entries with non-NEVER expiry if that table 299 * is getting 'full' for some definition of 'full' 300 * 301 * The question of "how often to scan a table" is an interesting one 302 * and is answered in part by the use of the "nextcheck" field in the 303 * cache_detail. 304 * When a scan of a table begins, the nextcheck field is set to a time 305 * that is well into the future. 306 * While scanning, if an expiry time is found that is earlier than the 307 * current nextcheck time, nextcheck is set to that expiry time. 308 * If the flush_time is ever set to a time earlier than the nextcheck 309 * time, the nextcheck time is then set to that flush_time. 310 * 311 * A table is then only scanned if the current time is at least 312 * the nextcheck time. 313 * 314 */ 315 316static LIST_HEAD(cache_list); 317static DEFINE_SPINLOCK(cache_list_lock); 318static struct cache_detail *current_detail; 319static int current_index; 320 321static void do_cache_clean(struct work_struct *work); 322static struct delayed_work cache_cleaner; 323 324static void sunrpc_init_cache_detail(struct cache_detail *cd) 325{ 326 rwlock_init(&cd->hash_lock); 327 INIT_LIST_HEAD(&cd->queue); 328 spin_lock(&cache_list_lock); 329 cd->nextcheck = 0; 330 cd->entries = 0; 331 atomic_set(&cd->readers, 0); 332 cd->last_close = 0; 333 cd->last_warn = -1; 334 list_add(&cd->others, &cache_list); 335 spin_unlock(&cache_list_lock); 336 337 /* start the cleaning process */ 338 schedule_delayed_work(&cache_cleaner, 0); 339} 340 341static void sunrpc_destroy_cache_detail(struct cache_detail *cd) 342{ 343 cache_purge(cd); 344 spin_lock(&cache_list_lock); 345 write_lock(&cd->hash_lock); 346 if (cd->entries || atomic_read(&cd->inuse)) { 347 write_unlock(&cd->hash_lock); 348 spin_unlock(&cache_list_lock); 349 goto out; 350 } 351 if (current_detail == cd) 352 current_detail = NULL; 353 list_del_init(&cd->others); 354 write_unlock(&cd->hash_lock); 355 spin_unlock(&cache_list_lock); 356 if (list_empty(&cache_list)) { 357 /* module must be being unloaded so its safe to kill the worker */ 358 cancel_delayed_work_sync(&cache_cleaner); 359 } 360 return; 361out: 362 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name); 363} 364 365/* clean cache tries to find something to clean 366 * and cleans it. 367 * It returns 1 if it cleaned something, 368 * 0 if it didn't find anything this time 369 * -1 if it fell off the end of the list. 370 */ 371static int cache_clean(void) 372{ 373 int rv = 0; 374 struct list_head *next; 375 376 spin_lock(&cache_list_lock); 377 378 /* find a suitable table if we don't already have one */ 379 while (current_detail == NULL || 380 current_index >= current_detail->hash_size) { 381 if (current_detail) 382 next = current_detail->others.next; 383 else 384 next = cache_list.next; 385 if (next == &cache_list) { 386 current_detail = NULL; 387 spin_unlock(&cache_list_lock); 388 return -1; 389 } 390 current_detail = list_entry(next, struct cache_detail, others); 391 if (current_detail->nextcheck > seconds_since_boot()) 392 current_index = current_detail->hash_size; 393 else { 394 current_index = 0; 395 current_detail->nextcheck = seconds_since_boot()+30*60; 396 } 397 } 398 399 /* find a non-empty bucket in the table */ 400 while (current_detail && 401 current_index < current_detail->hash_size && 402 current_detail->hash_table[current_index] == NULL) 403 current_index++; 404 405 /* find a cleanable entry in the bucket and clean it, or set to next bucket */ 406 407 if (current_detail && current_index < current_detail->hash_size) { 408 struct cache_head *ch, **cp; 409 struct cache_detail *d; 410 411 write_lock(¤t_detail->hash_lock); 412 413 /* Ok, now to clean this strand */ 414 415 cp = & current_detail->hash_table[current_index]; 416 for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) { 417 if (current_detail->nextcheck > ch->expiry_time) 418 current_detail->nextcheck = ch->expiry_time+1; 419 if (!cache_is_expired(current_detail, ch)) 420 continue; 421 422 *cp = ch->next; 423 ch->next = NULL; 424 current_detail->entries--; 425 rv = 1; 426 break; 427 } 428 429 write_unlock(¤t_detail->hash_lock); 430 d = current_detail; 431 if (!ch) 432 current_index ++; 433 spin_unlock(&cache_list_lock); 434 if (ch) { 435 if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) 436 cache_dequeue(current_detail, ch); 437 cache_revisit_request(ch); 438 cache_put(ch, d); 439 } 440 } else 441 spin_unlock(&cache_list_lock); 442 443 return rv; 444} 445 446/* 447 * We want to regularly clean the cache, so we need to schedule some work ... 448 */ 449static void do_cache_clean(struct work_struct *work) 450{ 451 int delay = 5; 452 if (cache_clean() == -1) 453 delay = round_jiffies_relative(30*HZ); 454 455 if (list_empty(&cache_list)) 456 delay = 0; 457 458 if (delay) 459 schedule_delayed_work(&cache_cleaner, delay); 460} 461 462 463/* 464 * Clean all caches promptly. This just calls cache_clean 465 * repeatedly until we are sure that every cache has had a chance to 466 * be fully cleaned 467 */ 468void cache_flush(void) 469{ 470 while (cache_clean() != -1) 471 cond_resched(); 472 while (cache_clean() != -1) 473 cond_resched(); 474} 475EXPORT_SYMBOL_GPL(cache_flush); 476 477void cache_purge(struct cache_detail *detail) 478{ 479 detail->flush_time = LONG_MAX; 480 detail->nextcheck = seconds_since_boot(); 481 cache_flush(); 482 detail->flush_time = 1; 483} 484EXPORT_SYMBOL_GPL(cache_purge); 485 486 487/* 488 * Deferral and Revisiting of Requests. 489 * 490 * If a cache lookup finds a pending entry, we 491 * need to defer the request and revisit it later. 492 * All deferred requests are stored in a hash table, 493 * indexed by "struct cache_head *". 494 * As it may be wasteful to store a whole request 495 * structure, we allow the request to provide a 496 * deferred form, which must contain a 497 * 'struct cache_deferred_req' 498 * This cache_deferred_req contains a method to allow 499 * it to be revisited when cache info is available 500 */ 501 502#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) 503#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) 504 505#define DFR_MAX 300 /* ??? */ 506 507static DEFINE_SPINLOCK(cache_defer_lock); 508static LIST_HEAD(cache_defer_list); 509static struct list_head cache_defer_hash[DFR_HASHSIZE]; 510static int cache_defer_cnt; 511 512static void __unhash_deferred_req(struct cache_deferred_req *dreq) 513{ 514 list_del_init(&dreq->recent); 515 list_del_init(&dreq->hash); 516 cache_defer_cnt--; 517} 518 519static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item) 520{ 521 int hash = DFR_HASH(item); 522 523 list_add(&dreq->recent, &cache_defer_list); 524 if (cache_defer_hash[hash].next == NULL) 525 INIT_LIST_HEAD(&cache_defer_hash[hash]); 526 list_add(&dreq->hash, &cache_defer_hash[hash]); 527} 528 529static int setup_deferral(struct cache_deferred_req *dreq, struct cache_head *item) 530{ 531 struct cache_deferred_req *discard; 532 533 dreq->item = item; 534 535 spin_lock(&cache_defer_lock); 536 537 __hash_deferred_req(dreq, item); 538 539 /* it is in, now maybe clean up */ 540 discard = NULL; 541 if (++cache_defer_cnt > DFR_MAX) { 542 discard = list_entry(cache_defer_list.prev, 543 struct cache_deferred_req, recent); 544 __unhash_deferred_req(discard); 545 } 546 spin_unlock(&cache_defer_lock); 547 548 if (discard) 549 /* there was one too many */ 550 discard->revisit(discard, 1); 551 552 if (!test_bit(CACHE_PENDING, &item->flags)) { 553 /* must have just been validated... */ 554 cache_revisit_request(item); 555 return -EAGAIN; 556 } 557 return 0; 558} 559 560struct thread_deferred_req { 561 struct cache_deferred_req handle; 562 struct completion completion; 563}; 564 565static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) 566{ 567 struct thread_deferred_req *dr = 568 container_of(dreq, struct thread_deferred_req, handle); 569 complete(&dr->completion); 570} 571 572static int cache_wait_req(struct cache_req *req, struct cache_head *item) 573{ 574 struct thread_deferred_req sleeper; 575 struct cache_deferred_req *dreq = &sleeper.handle; 576 int ret; 577 578 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); 579 dreq->revisit = cache_restart_thread; 580 581 ret = setup_deferral(dreq, item); 582 if (ret) 583 return ret; 584 585 if (wait_for_completion_interruptible_timeout( 586 &sleeper.completion, req->thread_wait) <= 0) { 587 /* The completion wasn't completed, so we need 588 * to clean up 589 */ 590 spin_lock(&cache_defer_lock); 591 if (!list_empty(&sleeper.handle.hash)) { 592 __unhash_deferred_req(&sleeper.handle); 593 spin_unlock(&cache_defer_lock); 594 } else { 595 /* cache_revisit_request already removed 596 * this from the hash table, but hasn't 597 * called ->revisit yet. It will very soon 598 * and we need to wait for it. 599 */ 600 spin_unlock(&cache_defer_lock); 601 wait_for_completion(&sleeper.completion); 602 } 603 } 604 if (test_bit(CACHE_PENDING, &item->flags)) { 605 /* item is still pending, try request 606 * deferral 607 */ 608 return -ETIMEDOUT; 609 } 610 /* only return success if we actually deferred the 611 * request. In this case we waited until it was 612 * answered so no deferral has happened - rather 613 * an answer already exists. 614 */ 615 return -EEXIST; 616} 617 618static int cache_defer_req(struct cache_req *req, struct cache_head *item) 619{ 620 struct cache_deferred_req *dreq; 621 int ret; 622 623 if (cache_defer_cnt >= DFR_MAX) { 624 /* too much in the cache, randomly drop this one, 625 * or continue and drop the oldest 626 */ 627 if (net_random()&1) 628 return -ENOMEM; 629 } 630 if (req->thread_wait) { 631 ret = cache_wait_req(req, item); 632 if (ret != -ETIMEDOUT) 633 return ret; 634 } 635 dreq = req->defer(req); 636 if (dreq == NULL) 637 return -ENOMEM; 638 return setup_deferral(dreq, item); 639} 640 641static void cache_revisit_request(struct cache_head *item) 642{ 643 struct cache_deferred_req *dreq; 644 struct list_head pending; 645 646 struct list_head *lp; 647 int hash = DFR_HASH(item); 648 649 INIT_LIST_HEAD(&pending); 650 spin_lock(&cache_defer_lock); 651 652 lp = cache_defer_hash[hash].next; 653 if (lp) { 654 while (lp != &cache_defer_hash[hash]) { 655 dreq = list_entry(lp, struct cache_deferred_req, hash); 656 lp = lp->next; 657 if (dreq->item == item) { 658 __unhash_deferred_req(dreq); 659 list_add(&dreq->recent, &pending); 660 } 661 } 662 } 663 spin_unlock(&cache_defer_lock); 664 665 while (!list_empty(&pending)) { 666 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 667 list_del_init(&dreq->recent); 668 dreq->revisit(dreq, 0); 669 } 670} 671 672void cache_clean_deferred(void *owner) 673{ 674 struct cache_deferred_req *dreq, *tmp; 675 struct list_head pending; 676 677 678 INIT_LIST_HEAD(&pending); 679 spin_lock(&cache_defer_lock); 680 681 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { 682 if (dreq->owner == owner) 683 __unhash_deferred_req(dreq); 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, 1); 691 } 692} 693 694/* 695 * communicate with user-space 696 * 697 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. 698 * On read, you get a full request, or block. 699 * On write, an update request is processed. 700 * Poll works if anything to read, and always allows write. 701 * 702 * Implemented by linked list of requests. Each open file has 703 * a ->private that also exists in this list. New requests are added 704 * to the end and may wakeup and preceding readers. 705 * New readers are added to the head. If, on read, an item is found with 706 * CACHE_UPCALLING clear, we free it from the list. 707 * 708 */ 709 710static DEFINE_SPINLOCK(queue_lock); 711static DEFINE_MUTEX(queue_io_mutex); 712 713struct cache_queue { 714 struct list_head list; 715 int reader; /* if 0, then request */ 716}; 717struct cache_request { 718 struct cache_queue q; 719 struct cache_head *item; 720 char * buf; 721 int len; 722 int readers; 723}; 724struct cache_reader { 725 struct cache_queue q; 726 int offset; /* if non-0, we have a refcnt on next request */ 727}; 728 729static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, 730 loff_t *ppos, struct cache_detail *cd) 731{ 732 struct cache_reader *rp = filp->private_data; 733 struct cache_request *rq; 734 struct inode *inode = filp->f_path.dentry->d_inode; 735 int err; 736 737 if (count == 0) 738 return 0; 739 740 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent 741 * readers on this file */ 742 again: 743 spin_lock(&queue_lock); 744 /* need to find next request */ 745 while (rp->q.list.next != &cd->queue && 746 list_entry(rp->q.list.next, struct cache_queue, list) 747 ->reader) { 748 struct list_head *next = rp->q.list.next; 749 list_move(&rp->q.list, next); 750 } 751 if (rp->q.list.next == &cd->queue) { 752 spin_unlock(&queue_lock); 753 mutex_unlock(&inode->i_mutex); 754 BUG_ON(rp->offset); 755 return 0; 756 } 757 rq = container_of(rp->q.list.next, struct cache_request, q.list); 758 BUG_ON(rq->q.reader); 759 if (rp->offset == 0) 760 rq->readers++; 761 spin_unlock(&queue_lock); 762 763 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { 764 err = -EAGAIN; 765 spin_lock(&queue_lock); 766 list_move(&rp->q.list, &rq->q.list); 767 spin_unlock(&queue_lock); 768 } else { 769 if (rp->offset + count > rq->len) 770 count = rq->len - rp->offset; 771 err = -EFAULT; 772 if (copy_to_user(buf, rq->buf + rp->offset, count)) 773 goto out; 774 rp->offset += count; 775 if (rp->offset >= rq->len) { 776 rp->offset = 0; 777 spin_lock(&queue_lock); 778 list_move(&rp->q.list, &rq->q.list); 779 spin_unlock(&queue_lock); 780 } 781 err = 0; 782 } 783 out: 784 if (rp->offset == 0) { 785 /* need to release rq */ 786 spin_lock(&queue_lock); 787 rq->readers--; 788 if (rq->readers == 0 && 789 !test_bit(CACHE_PENDING, &rq->item->flags)) { 790 list_del(&rq->q.list); 791 spin_unlock(&queue_lock); 792 cache_put(rq->item, cd); 793 kfree(rq->buf); 794 kfree(rq); 795 } else 796 spin_unlock(&queue_lock); 797 } 798 if (err == -EAGAIN) 799 goto again; 800 mutex_unlock(&inode->i_mutex); 801 return err ? err : count; 802} 803 804static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, 805 size_t count, struct cache_detail *cd) 806{ 807 ssize_t ret; 808 809 if (copy_from_user(kaddr, buf, count)) 810 return -EFAULT; 811 kaddr[count] = '\0'; 812 ret = cd->cache_parse(cd, kaddr, count); 813 if (!ret) 814 ret = count; 815 return ret; 816} 817 818static ssize_t cache_slow_downcall(const char __user *buf, 819 size_t count, struct cache_detail *cd) 820{ 821 static char write_buf[8192]; /* protected by queue_io_mutex */ 822 ssize_t ret = -EINVAL; 823 824 if (count >= sizeof(write_buf)) 825 goto out; 826 mutex_lock(&queue_io_mutex); 827 ret = cache_do_downcall(write_buf, buf, count, cd); 828 mutex_unlock(&queue_io_mutex); 829out: 830 return ret; 831} 832 833static ssize_t cache_downcall(struct address_space *mapping, 834 const char __user *buf, 835 size_t count, struct cache_detail *cd) 836{ 837 struct page *page; 838 char *kaddr; 839 ssize_t ret = -ENOMEM; 840 841 if (count >= PAGE_CACHE_SIZE) 842 goto out_slow; 843 844 page = find_or_create_page(mapping, 0, GFP_KERNEL); 845 if (!page) 846 goto out_slow; 847 848 kaddr = kmap(page); 849 ret = cache_do_downcall(kaddr, buf, count, cd); 850 kunmap(page); 851 unlock_page(page); 852 page_cache_release(page); 853 return ret; 854out_slow: 855 return cache_slow_downcall(buf, count, cd); 856} 857 858static ssize_t cache_write(struct file *filp, const char __user *buf, 859 size_t count, loff_t *ppos, 860 struct cache_detail *cd) 861{ 862 struct address_space *mapping = filp->f_mapping; 863 struct inode *inode = filp->f_path.dentry->d_inode; 864 ssize_t ret = -EINVAL; 865 866 if (!cd->cache_parse) 867 goto out; 868 869 mutex_lock(&inode->i_mutex); 870 ret = cache_downcall(mapping, buf, count, cd); 871 mutex_unlock(&inode->i_mutex); 872out: 873 return ret; 874} 875 876static DECLARE_WAIT_QUEUE_HEAD(queue_wait); 877 878static unsigned int cache_poll(struct file *filp, poll_table *wait, 879 struct cache_detail *cd) 880{ 881 unsigned int mask; 882 struct cache_reader *rp = filp->private_data; 883 struct cache_queue *cq; 884 885 poll_wait(filp, &queue_wait, wait); 886 887 /* alway allow write */ 888 mask = POLL_OUT | POLLWRNORM; 889 890 if (!rp) 891 return mask; 892 893 spin_lock(&queue_lock); 894 895 for (cq= &rp->q; &cq->list != &cd->queue; 896 cq = list_entry(cq->list.next, struct cache_queue, list)) 897 if (!cq->reader) { 898 mask |= POLLIN | POLLRDNORM; 899 break; 900 } 901 spin_unlock(&queue_lock); 902 return mask; 903} 904 905static int cache_ioctl(struct inode *ino, struct file *filp, 906 unsigned int cmd, unsigned long arg, 907 struct cache_detail *cd) 908{ 909 int len = 0; 910 struct cache_reader *rp = filp->private_data; 911 struct cache_queue *cq; 912 913 if (cmd != FIONREAD || !rp) 914 return -EINVAL; 915 916 spin_lock(&queue_lock); 917 918 /* only find the length remaining in current request, 919 * or the length of the next request 920 */ 921 for (cq= &rp->q; &cq->list != &cd->queue; 922 cq = list_entry(cq->list.next, struct cache_queue, list)) 923 if (!cq->reader) { 924 struct cache_request *cr = 925 container_of(cq, struct cache_request, q); 926 len = cr->len - rp->offset; 927 break; 928 } 929 spin_unlock(&queue_lock); 930 931 return put_user(len, (int __user *)arg); 932} 933 934static int cache_open(struct inode *inode, struct file *filp, 935 struct cache_detail *cd) 936{ 937 struct cache_reader *rp = NULL; 938 939 if (!cd || !try_module_get(cd->owner)) 940 return -EACCES; 941 nonseekable_open(inode, filp); 942 if (filp->f_mode & FMODE_READ) { 943 rp = kmalloc(sizeof(*rp), GFP_KERNEL); 944 if (!rp) 945 return -ENOMEM; 946 rp->offset = 0; 947 rp->q.reader = 1; 948 atomic_inc(&cd->readers); 949 spin_lock(&queue_lock); 950 list_add(&rp->q.list, &cd->queue); 951 spin_unlock(&queue_lock); 952 } 953 filp->private_data = rp; 954 return 0; 955} 956 957static int cache_release(struct inode *inode, struct file *filp, 958 struct cache_detail *cd) 959{ 960 struct cache_reader *rp = filp->private_data; 961 962 if (rp) { 963 spin_lock(&queue_lock); 964 if (rp->offset) { 965 struct cache_queue *cq; 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 container_of(cq, struct cache_request, q) 970 ->readers--; 971 break; 972 } 973 rp->offset = 0; 974 } 975 list_del(&rp->q.list); 976 spin_unlock(&queue_lock); 977 978 filp->private_data = NULL; 979 kfree(rp); 980 981 cd->last_close = seconds_since_boot(); 982 atomic_dec(&cd->readers); 983 } 984 module_put(cd->owner); 985 return 0; 986} 987 988 989 990static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) 991{ 992 struct cache_queue *cq; 993 spin_lock(&queue_lock); 994 list_for_each_entry(cq, &detail->queue, list) 995 if (!cq->reader) { 996 struct cache_request *cr = container_of(cq, struct cache_request, q); 997 if (cr->item != ch) 998 continue; 999 if (cr->readers != 0) 1000 continue; 1001 list_del(&cr->q.list); 1002 spin_unlock(&queue_lock); 1003 cache_put(cr->item, detail); 1004 kfree(cr->buf); 1005 kfree(cr); 1006 return; 1007 } 1008 spin_unlock(&queue_lock); 1009} 1010 1011/* 1012 * Support routines for text-based upcalls. 1013 * Fields are separated by spaces. 1014 * Fields are either mangled to quote space tab newline slosh with slosh 1015 * or a hexified with a leading \x 1016 * Record is terminated with newline. 1017 * 1018 */ 1019 1020void qword_add(char **bpp, int *lp, char *str) 1021{ 1022 char *bp = *bpp; 1023 int len = *lp; 1024 char c; 1025 1026 if (len < 0) return; 1027 1028 while ((c=*str++) && len) 1029 switch(c) { 1030 case ' ': 1031 case '\t': 1032 case '\n': 1033 case '\\': 1034 if (len >= 4) { 1035 *bp++ = '\\'; 1036 *bp++ = '0' + ((c & 0300)>>6); 1037 *bp++ = '0' + ((c & 0070)>>3); 1038 *bp++ = '0' + ((c & 0007)>>0); 1039 } 1040 len -= 4; 1041 break; 1042 default: 1043 *bp++ = c; 1044 len--; 1045 } 1046 if (c || len <1) len = -1; 1047 else { 1048 *bp++ = ' '; 1049 len--; 1050 } 1051 *bpp = bp; 1052 *lp = len; 1053} 1054EXPORT_SYMBOL_GPL(qword_add); 1055 1056void qword_addhex(char **bpp, int *lp, char *buf, int blen) 1057{ 1058 char *bp = *bpp; 1059 int len = *lp; 1060 1061 if (len < 0) return; 1062 1063 if (len > 2) { 1064 *bp++ = '\\'; 1065 *bp++ = 'x'; 1066 len -= 2; 1067 while (blen && len >= 2) { 1068 unsigned char c = *buf++; 1069 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 1070 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 1071 len -= 2; 1072 blen--; 1073 } 1074 } 1075 if (blen || len<1) len = -1; 1076 else { 1077 *bp++ = ' '; 1078 len--; 1079 } 1080 *bpp = bp; 1081 *lp = len; 1082} 1083EXPORT_SYMBOL_GPL(qword_addhex); 1084 1085static void warn_no_listener(struct cache_detail *detail) 1086{ 1087 if (detail->last_warn != detail->last_close) { 1088 detail->last_warn = detail->last_close; 1089 if (detail->warn_no_listener) 1090 detail->warn_no_listener(detail, detail->last_close != 0); 1091 } 1092} 1093 1094static bool cache_listeners_exist(struct cache_detail *detail) 1095{ 1096 if (atomic_read(&detail->readers)) 1097 return true; 1098 if (detail->last_close == 0) 1099 /* This cache was never opened */ 1100 return false; 1101 if (detail->last_close < seconds_since_boot() - 30) 1102 /* 1103 * We allow for the possibility that someone might 1104 * restart a userspace daemon without restarting the 1105 * server; but after 30 seconds, we give up. 1106 */ 1107 return false; 1108 return true; 1109} 1110 1111/* 1112 * register an upcall request to user-space and queue it up for read() by the 1113 * upcall daemon. 1114 * 1115 * Each request is at most one page long. 1116 */ 1117int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, 1118 void (*cache_request)(struct cache_detail *, 1119 struct cache_head *, 1120 char **, 1121 int *)) 1122{ 1123 1124 char *buf; 1125 struct cache_request *crq; 1126 char *bp; 1127 int len; 1128 1129 if (!cache_listeners_exist(detail)) { 1130 warn_no_listener(detail); 1131 return -EINVAL; 1132 } 1133 1134 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 1135 if (!buf) 1136 return -EAGAIN; 1137 1138 crq = kmalloc(sizeof (*crq), GFP_KERNEL); 1139 if (!crq) { 1140 kfree(buf); 1141 return -EAGAIN; 1142 } 1143 1144 bp = buf; len = PAGE_SIZE; 1145 1146 cache_request(detail, h, &bp, &len); 1147 1148 if (len < 0) { 1149 kfree(buf); 1150 kfree(crq); 1151 return -EAGAIN; 1152 } 1153 crq->q.reader = 0; 1154 crq->item = cache_get(h); 1155 crq->buf = buf; 1156 crq->len = PAGE_SIZE - len; 1157 crq->readers = 0; 1158 spin_lock(&queue_lock); 1159 list_add_tail(&crq->q.list, &detail->queue); 1160 spin_unlock(&queue_lock); 1161 wake_up(&queue_wait); 1162 return 0; 1163} 1164EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); 1165 1166/* 1167 * parse a message from user-space and pass it 1168 * to an appropriate cache 1169 * Messages are, like requests, separated into fields by 1170 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal 1171 * 1172 * Message is 1173 * reply cachename expiry key ... content.... 1174 * 1175 * key and content are both parsed by cache 1176 */ 1177 1178#define isodigit(c) (isdigit(c) && c <= '7') 1179int qword_get(char **bpp, char *dest, int bufsize) 1180{ 1181 /* return bytes copied, or -1 on error */ 1182 char *bp = *bpp; 1183 int len = 0; 1184 1185 while (*bp == ' ') bp++; 1186 1187 if (bp[0] == '\\' && bp[1] == 'x') { 1188 /* HEX STRING */ 1189 bp += 2; 1190 while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { 1191 int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; 1192 bp++; 1193 byte <<= 4; 1194 byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; 1195 *dest++ = byte; 1196 bp++; 1197 len++; 1198 } 1199 } else { 1200 /* text with \nnn octal quoting */ 1201 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { 1202 if (*bp == '\\' && 1203 isodigit(bp[1]) && (bp[1] <= '3') && 1204 isodigit(bp[2]) && 1205 isodigit(bp[3])) { 1206 int byte = (*++bp -'0'); 1207 bp++; 1208 byte = (byte << 3) | (*bp++ - '0'); 1209 byte = (byte << 3) | (*bp++ - '0'); 1210 *dest++ = byte; 1211 len++; 1212 } else { 1213 *dest++ = *bp++; 1214 len++; 1215 } 1216 } 1217 } 1218 1219 if (*bp != ' ' && *bp != '\n' && *bp != '\0') 1220 return -1; 1221 while (*bp == ' ') bp++; 1222 *bpp = bp; 1223 *dest = '\0'; 1224 return len; 1225} 1226EXPORT_SYMBOL_GPL(qword_get); 1227 1228 1229/* 1230 * support /proc/sunrpc/cache/$CACHENAME/content 1231 * as a seqfile. 1232 * We call ->cache_show passing NULL for the item to 1233 * get a header, then pass each real item in the cache 1234 */ 1235 1236struct handle { 1237 struct cache_detail *cd; 1238}; 1239 1240static void *c_start(struct seq_file *m, loff_t *pos) 1241 __acquires(cd->hash_lock) 1242{ 1243 loff_t n = *pos; 1244 unsigned hash, entry; 1245 struct cache_head *ch; 1246 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1247 1248 1249 read_lock(&cd->hash_lock); 1250 if (!n--) 1251 return SEQ_START_TOKEN; 1252 hash = n >> 32; 1253 entry = n & ((1LL<<32) - 1); 1254 1255 for (ch=cd->hash_table[hash]; ch; ch=ch->next) 1256 if (!entry--) 1257 return ch; 1258 n &= ~((1LL<<32) - 1); 1259 do { 1260 hash++; 1261 n += 1LL<<32; 1262 } while(hash < cd->hash_size && 1263 cd->hash_table[hash]==NULL); 1264 if (hash >= cd->hash_size) 1265 return NULL; 1266 *pos = n+1; 1267 return cd->hash_table[hash]; 1268} 1269 1270static void *c_next(struct seq_file *m, void *p, loff_t *pos) 1271{ 1272 struct cache_head *ch = p; 1273 int hash = (*pos >> 32); 1274 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1275 1276 if (p == SEQ_START_TOKEN) 1277 hash = 0; 1278 else if (ch->next == NULL) { 1279 hash++; 1280 *pos += 1LL<<32; 1281 } else { 1282 ++*pos; 1283 return ch->next; 1284 } 1285 *pos &= ~((1LL<<32) - 1); 1286 while (hash < cd->hash_size && 1287 cd->hash_table[hash] == NULL) { 1288 hash++; 1289 *pos += 1LL<<32; 1290 } 1291 if (hash >= cd->hash_size) 1292 return NULL; 1293 ++*pos; 1294 return cd->hash_table[hash]; 1295} 1296 1297static void c_stop(struct seq_file *m, void *p) 1298 __releases(cd->hash_lock) 1299{ 1300 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1301 read_unlock(&cd->hash_lock); 1302} 1303 1304static int c_show(struct seq_file *m, void *p) 1305{ 1306 struct cache_head *cp = p; 1307 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1308 1309 if (p == SEQ_START_TOKEN) 1310 return cd->cache_show(m, cd, NULL); 1311 1312 ifdebug(CACHE) 1313 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", 1314 convert_to_wallclock(cp->expiry_time), 1315 atomic_read(&cp->ref.refcount), cp->flags); 1316 cache_get(cp); 1317 if (cache_check(cd, cp, NULL)) 1318 /* cache_check does a cache_put on failure */ 1319 seq_printf(m, "# "); 1320 else 1321 cache_put(cp, cd); 1322 1323 return cd->cache_show(m, cd, cp); 1324} 1325 1326static const struct seq_operations cache_content_op = { 1327 .start = c_start, 1328 .next = c_next, 1329 .stop = c_stop, 1330 .show = c_show, 1331}; 1332 1333static int content_open(struct inode *inode, struct file *file, 1334 struct cache_detail *cd) 1335{ 1336 struct handle *han; 1337 1338 if (!cd || !try_module_get(cd->owner)) 1339 return -EACCES; 1340 han = __seq_open_private(file, &cache_content_op, sizeof(*han)); 1341 if (han == NULL) { 1342 module_put(cd->owner); 1343 return -ENOMEM; 1344 } 1345 1346 han->cd = cd; 1347 return 0; 1348} 1349 1350static int content_release(struct inode *inode, struct file *file, 1351 struct cache_detail *cd) 1352{ 1353 int ret = seq_release_private(inode, file); 1354 module_put(cd->owner); 1355 return ret; 1356} 1357 1358static int open_flush(struct inode *inode, struct file *file, 1359 struct cache_detail *cd) 1360{ 1361 if (!cd || !try_module_get(cd->owner)) 1362 return -EACCES; 1363 return nonseekable_open(inode, file); 1364} 1365 1366static int release_flush(struct inode *inode, struct file *file, 1367 struct cache_detail *cd) 1368{ 1369 module_put(cd->owner); 1370 return 0; 1371} 1372 1373static ssize_t read_flush(struct file *file, char __user *buf, 1374 size_t count, loff_t *ppos, 1375 struct cache_detail *cd) 1376{ 1377 char tbuf[20]; 1378 unsigned long p = *ppos; 1379 size_t len; 1380 1381 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time)); 1382 len = strlen(tbuf); 1383 if (p >= len) 1384 return 0; 1385 len -= p; 1386 if (len > count) 1387 len = count; 1388 if (copy_to_user(buf, (void*)(tbuf+p), len)) 1389 return -EFAULT; 1390 *ppos += len; 1391 return len; 1392} 1393 1394static ssize_t write_flush(struct file *file, const char __user *buf, 1395 size_t count, loff_t *ppos, 1396 struct cache_detail *cd) 1397{ 1398 char tbuf[20]; 1399 char *bp, *ep; 1400 1401 if (*ppos || count > sizeof(tbuf)-1) 1402 return -EINVAL; 1403 if (copy_from_user(tbuf, buf, count)) 1404 return -EFAULT; 1405 tbuf[count] = 0; 1406 simple_strtoul(tbuf, &ep, 0); 1407 if (*ep && *ep != '\n') 1408 return -EINVAL; 1409 1410 bp = tbuf; 1411 cd->flush_time = get_expiry(&bp); 1412 cd->nextcheck = seconds_since_boot(); 1413 cache_flush(); 1414 1415 *ppos += count; 1416 return count; 1417} 1418 1419static ssize_t cache_read_procfs(struct file *filp, char __user *buf, 1420 size_t count, loff_t *ppos) 1421{ 1422 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1423 1424 return cache_read(filp, buf, count, ppos, cd); 1425} 1426 1427static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, 1428 size_t count, loff_t *ppos) 1429{ 1430 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1431 1432 return cache_write(filp, buf, count, ppos, cd); 1433} 1434 1435static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) 1436{ 1437 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1438 1439 return cache_poll(filp, wait, cd); 1440} 1441 1442static long cache_ioctl_procfs(struct file *filp, 1443 unsigned int cmd, unsigned long arg) 1444{ 1445 long ret; 1446 struct inode *inode = filp->f_path.dentry->d_inode; 1447 struct cache_detail *cd = PDE(inode)->data; 1448 1449 lock_kernel(); 1450 ret = cache_ioctl(inode, filp, cmd, arg, cd); 1451 unlock_kernel(); 1452 1453 return ret; 1454} 1455 1456static int cache_open_procfs(struct inode *inode, struct file *filp) 1457{ 1458 struct cache_detail *cd = PDE(inode)->data; 1459 1460 return cache_open(inode, filp, cd); 1461} 1462 1463static int cache_release_procfs(struct inode *inode, struct file *filp) 1464{ 1465 struct cache_detail *cd = PDE(inode)->data; 1466 1467 return cache_release(inode, filp, cd); 1468} 1469 1470static const struct file_operations cache_file_operations_procfs = { 1471 .owner = THIS_MODULE, 1472 .llseek = no_llseek, 1473 .read = cache_read_procfs, 1474 .write = cache_write_procfs, 1475 .poll = cache_poll_procfs, 1476 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ 1477 .open = cache_open_procfs, 1478 .release = cache_release_procfs, 1479}; 1480 1481static int content_open_procfs(struct inode *inode, struct file *filp) 1482{ 1483 struct cache_detail *cd = PDE(inode)->data; 1484 1485 return content_open(inode, filp, cd); 1486} 1487 1488static int content_release_procfs(struct inode *inode, struct file *filp) 1489{ 1490 struct cache_detail *cd = PDE(inode)->data; 1491 1492 return content_release(inode, filp, cd); 1493} 1494 1495static const struct file_operations content_file_operations_procfs = { 1496 .open = content_open_procfs, 1497 .read = seq_read, 1498 .llseek = seq_lseek, 1499 .release = content_release_procfs, 1500}; 1501 1502static int open_flush_procfs(struct inode *inode, struct file *filp) 1503{ 1504 struct cache_detail *cd = PDE(inode)->data; 1505 1506 return open_flush(inode, filp, cd); 1507} 1508 1509static int release_flush_procfs(struct inode *inode, struct file *filp) 1510{ 1511 struct cache_detail *cd = PDE(inode)->data; 1512 1513 return release_flush(inode, filp, cd); 1514} 1515 1516static ssize_t read_flush_procfs(struct file *filp, char __user *buf, 1517 size_t count, loff_t *ppos) 1518{ 1519 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1520 1521 return read_flush(filp, buf, count, ppos, cd); 1522} 1523 1524static ssize_t write_flush_procfs(struct file *filp, 1525 const char __user *buf, 1526 size_t count, loff_t *ppos) 1527{ 1528 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1529 1530 return write_flush(filp, buf, count, ppos, cd); 1531} 1532 1533static const struct file_operations cache_flush_operations_procfs = { 1534 .open = open_flush_procfs, 1535 .read = read_flush_procfs, 1536 .write = write_flush_procfs, 1537 .release = release_flush_procfs, 1538}; 1539 1540static void remove_cache_proc_entries(struct cache_detail *cd) 1541{ 1542 if (cd->u.procfs.proc_ent == NULL) 1543 return; 1544 if (cd->u.procfs.flush_ent) 1545 remove_proc_entry("flush", cd->u.procfs.proc_ent); 1546 if (cd->u.procfs.channel_ent) 1547 remove_proc_entry("channel", cd->u.procfs.proc_ent); 1548 if (cd->u.procfs.content_ent) 1549 remove_proc_entry("content", cd->u.procfs.proc_ent); 1550 cd->u.procfs.proc_ent = NULL; 1551 remove_proc_entry(cd->name, proc_net_rpc); 1552} 1553 1554#ifdef CONFIG_PROC_FS 1555static int create_cache_proc_entries(struct cache_detail *cd) 1556{ 1557 struct proc_dir_entry *p; 1558 1559 cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc); 1560 if (cd->u.procfs.proc_ent == NULL) 1561 goto out_nomem; 1562 cd->u.procfs.channel_ent = NULL; 1563 cd->u.procfs.content_ent = NULL; 1564 1565 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, 1566 cd->u.procfs.proc_ent, 1567 &cache_flush_operations_procfs, cd); 1568 cd->u.procfs.flush_ent = p; 1569 if (p == NULL) 1570 goto out_nomem; 1571 1572 if (cd->cache_upcall || cd->cache_parse) { 1573 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, 1574 cd->u.procfs.proc_ent, 1575 &cache_file_operations_procfs, cd); 1576 cd->u.procfs.channel_ent = p; 1577 if (p == NULL) 1578 goto out_nomem; 1579 } 1580 if (cd->cache_show) { 1581 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, 1582 cd->u.procfs.proc_ent, 1583 &content_file_operations_procfs, cd); 1584 cd->u.procfs.content_ent = p; 1585 if (p == NULL) 1586 goto out_nomem; 1587 } 1588 return 0; 1589out_nomem: 1590 remove_cache_proc_entries(cd); 1591 return -ENOMEM; 1592} 1593#else /* CONFIG_PROC_FS */ 1594static int create_cache_proc_entries(struct cache_detail *cd) 1595{ 1596 return 0; 1597} 1598#endif 1599 1600void __init cache_initialize(void) 1601{ 1602 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean); 1603} 1604 1605int cache_register(struct cache_detail *cd) 1606{ 1607 int ret; 1608 1609 sunrpc_init_cache_detail(cd); 1610 ret = create_cache_proc_entries(cd); 1611 if (ret) 1612 sunrpc_destroy_cache_detail(cd); 1613 return ret; 1614} 1615EXPORT_SYMBOL_GPL(cache_register); 1616 1617void cache_unregister(struct cache_detail *cd) 1618{ 1619 remove_cache_proc_entries(cd); 1620 sunrpc_destroy_cache_detail(cd); 1621} 1622EXPORT_SYMBOL_GPL(cache_unregister); 1623 1624static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, 1625 size_t count, loff_t *ppos) 1626{ 1627 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1628 1629 return cache_read(filp, buf, count, ppos, cd); 1630} 1631 1632static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, 1633 size_t count, loff_t *ppos) 1634{ 1635 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1636 1637 return cache_write(filp, buf, count, ppos, cd); 1638} 1639 1640static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) 1641{ 1642 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1643 1644 return cache_poll(filp, wait, cd); 1645} 1646 1647static long cache_ioctl_pipefs(struct file *filp, 1648 unsigned int cmd, unsigned long arg) 1649{ 1650 struct inode *inode = filp->f_dentry->d_inode; 1651 struct cache_detail *cd = RPC_I(inode)->private; 1652 long ret; 1653 1654 lock_kernel(); 1655 ret = cache_ioctl(inode, filp, cmd, arg, cd); 1656 unlock_kernel(); 1657 1658 return ret; 1659} 1660 1661static int cache_open_pipefs(struct inode *inode, struct file *filp) 1662{ 1663 struct cache_detail *cd = RPC_I(inode)->private; 1664 1665 return cache_open(inode, filp, cd); 1666} 1667 1668static int cache_release_pipefs(struct inode *inode, struct file *filp) 1669{ 1670 struct cache_detail *cd = RPC_I(inode)->private; 1671 1672 return cache_release(inode, filp, cd); 1673} 1674 1675const struct file_operations cache_file_operations_pipefs = { 1676 .owner = THIS_MODULE, 1677 .llseek = no_llseek, 1678 .read = cache_read_pipefs, 1679 .write = cache_write_pipefs, 1680 .poll = cache_poll_pipefs, 1681 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ 1682 .open = cache_open_pipefs, 1683 .release = cache_release_pipefs, 1684}; 1685 1686static int content_open_pipefs(struct inode *inode, struct file *filp) 1687{ 1688 struct cache_detail *cd = RPC_I(inode)->private; 1689 1690 return content_open(inode, filp, cd); 1691} 1692 1693static int content_release_pipefs(struct inode *inode, struct file *filp) 1694{ 1695 struct cache_detail *cd = RPC_I(inode)->private; 1696 1697 return content_release(inode, filp, cd); 1698} 1699 1700const struct file_operations content_file_operations_pipefs = { 1701 .open = content_open_pipefs, 1702 .read = seq_read, 1703 .llseek = seq_lseek, 1704 .release = content_release_pipefs, 1705}; 1706 1707static int open_flush_pipefs(struct inode *inode, struct file *filp) 1708{ 1709 struct cache_detail *cd = RPC_I(inode)->private; 1710 1711 return open_flush(inode, filp, cd); 1712} 1713 1714static int release_flush_pipefs(struct inode *inode, struct file *filp) 1715{ 1716 struct cache_detail *cd = RPC_I(inode)->private; 1717 1718 return release_flush(inode, filp, cd); 1719} 1720 1721static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, 1722 size_t count, loff_t *ppos) 1723{ 1724 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1725 1726 return read_flush(filp, buf, count, ppos, cd); 1727} 1728 1729static ssize_t write_flush_pipefs(struct file *filp, 1730 const char __user *buf, 1731 size_t count, loff_t *ppos) 1732{ 1733 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1734 1735 return write_flush(filp, buf, count, ppos, cd); 1736} 1737 1738const struct file_operations cache_flush_operations_pipefs = { 1739 .open = open_flush_pipefs, 1740 .read = read_flush_pipefs, 1741 .write = write_flush_pipefs, 1742 .release = release_flush_pipefs, 1743}; 1744 1745int sunrpc_cache_register_pipefs(struct dentry *parent, 1746 const char *name, mode_t umode, 1747 struct cache_detail *cd) 1748{ 1749 struct qstr q; 1750 struct dentry *dir; 1751 int ret = 0; 1752 1753 sunrpc_init_cache_detail(cd); 1754 q.name = name; 1755 q.len = strlen(name); 1756 q.hash = full_name_hash(q.name, q.len); 1757 dir = rpc_create_cache_dir(parent, &q, umode, cd); 1758 if (!IS_ERR(dir)) 1759 cd->u.pipefs.dir = dir; 1760 else { 1761 sunrpc_destroy_cache_detail(cd); 1762 ret = PTR_ERR(dir); 1763 } 1764 return ret; 1765} 1766EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); 1767 1768void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) 1769{ 1770 rpc_remove_cache_dir(cd->u.pipefs.dir); 1771 cd->u.pipefs.dir = NULL; 1772 sunrpc_destroy_cache_detail(cd); 1773} 1774EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); 1775 1776