cache.c revision e7f483eabea8ef6d2b5ce1b74c8184cc06819f15
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 hlist_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 hlist_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 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]); 525} 526 527static int setup_deferral(struct cache_deferred_req *dreq, struct cache_head *item) 528{ 529 struct cache_deferred_req *discard; 530 531 dreq->item = item; 532 533 spin_lock(&cache_defer_lock); 534 535 __hash_deferred_req(dreq, item); 536 537 /* it is in, now maybe clean up */ 538 discard = NULL; 539 if (++cache_defer_cnt > DFR_MAX) { 540 discard = list_entry(cache_defer_list.prev, 541 struct cache_deferred_req, recent); 542 __unhash_deferred_req(discard); 543 } 544 spin_unlock(&cache_defer_lock); 545 546 if (discard) 547 /* there was one too many */ 548 discard->revisit(discard, 1); 549 550 if (!test_bit(CACHE_PENDING, &item->flags)) { 551 /* must have just been validated... */ 552 cache_revisit_request(item); 553 return -EAGAIN; 554 } 555 return 0; 556} 557 558struct thread_deferred_req { 559 struct cache_deferred_req handle; 560 struct completion completion; 561}; 562 563static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) 564{ 565 struct thread_deferred_req *dr = 566 container_of(dreq, struct thread_deferred_req, handle); 567 complete(&dr->completion); 568} 569 570static int cache_wait_req(struct cache_req *req, struct cache_head *item) 571{ 572 struct thread_deferred_req sleeper; 573 struct cache_deferred_req *dreq = &sleeper.handle; 574 int ret; 575 576 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); 577 dreq->revisit = cache_restart_thread; 578 579 ret = setup_deferral(dreq, item); 580 if (ret) 581 return ret; 582 583 if (wait_for_completion_interruptible_timeout( 584 &sleeper.completion, req->thread_wait) <= 0) { 585 /* The completion wasn't completed, so we need 586 * to clean up 587 */ 588 spin_lock(&cache_defer_lock); 589 if (!hlist_unhashed(&sleeper.handle.hash)) { 590 __unhash_deferred_req(&sleeper.handle); 591 spin_unlock(&cache_defer_lock); 592 } else { 593 /* cache_revisit_request already removed 594 * this from the hash table, but hasn't 595 * called ->revisit yet. It will very soon 596 * and we need to wait for it. 597 */ 598 spin_unlock(&cache_defer_lock); 599 wait_for_completion(&sleeper.completion); 600 } 601 } 602 if (test_bit(CACHE_PENDING, &item->flags)) { 603 /* item is still pending, try request 604 * deferral 605 */ 606 return -ETIMEDOUT; 607 } 608 /* only return success if we actually deferred the 609 * request. In this case we waited until it was 610 * answered so no deferral has happened - rather 611 * an answer already exists. 612 */ 613 return -EEXIST; 614} 615 616static int cache_defer_req(struct cache_req *req, struct cache_head *item) 617{ 618 struct cache_deferred_req *dreq; 619 int ret; 620 621 if (cache_defer_cnt >= DFR_MAX) { 622 /* too much in the cache, randomly drop this one, 623 * or continue and drop the oldest 624 */ 625 if (net_random()&1) 626 return -ENOMEM; 627 } 628 if (req->thread_wait) { 629 ret = cache_wait_req(req, item); 630 if (ret != -ETIMEDOUT) 631 return ret; 632 } 633 dreq = req->defer(req); 634 if (dreq == NULL) 635 return -ENOMEM; 636 return setup_deferral(dreq, item); 637} 638 639static void cache_revisit_request(struct cache_head *item) 640{ 641 struct cache_deferred_req *dreq; 642 struct list_head pending; 643 struct hlist_node *lp, *tmp; 644 int hash = DFR_HASH(item); 645 646 INIT_LIST_HEAD(&pending); 647 spin_lock(&cache_defer_lock); 648 649 hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash) 650 if (dreq->item == item) { 651 __unhash_deferred_req(dreq); 652 list_add(&dreq->recent, &pending); 653 } 654 655 spin_unlock(&cache_defer_lock); 656 657 while (!list_empty(&pending)) { 658 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 659 list_del_init(&dreq->recent); 660 dreq->revisit(dreq, 0); 661 } 662} 663 664void cache_clean_deferred(void *owner) 665{ 666 struct cache_deferred_req *dreq, *tmp; 667 struct list_head pending; 668 669 670 INIT_LIST_HEAD(&pending); 671 spin_lock(&cache_defer_lock); 672 673 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { 674 if (dreq->owner == owner) 675 __unhash_deferred_req(dreq); 676 } 677 spin_unlock(&cache_defer_lock); 678 679 while (!list_empty(&pending)) { 680 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 681 list_del_init(&dreq->recent); 682 dreq->revisit(dreq, 1); 683 } 684} 685 686/* 687 * communicate with user-space 688 * 689 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. 690 * On read, you get a full request, or block. 691 * On write, an update request is processed. 692 * Poll works if anything to read, and always allows write. 693 * 694 * Implemented by linked list of requests. Each open file has 695 * a ->private that also exists in this list. New requests are added 696 * to the end and may wakeup and preceding readers. 697 * New readers are added to the head. If, on read, an item is found with 698 * CACHE_UPCALLING clear, we free it from the list. 699 * 700 */ 701 702static DEFINE_SPINLOCK(queue_lock); 703static DEFINE_MUTEX(queue_io_mutex); 704 705struct cache_queue { 706 struct list_head list; 707 int reader; /* if 0, then request */ 708}; 709struct cache_request { 710 struct cache_queue q; 711 struct cache_head *item; 712 char * buf; 713 int len; 714 int readers; 715}; 716struct cache_reader { 717 struct cache_queue q; 718 int offset; /* if non-0, we have a refcnt on next request */ 719}; 720 721static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, 722 loff_t *ppos, struct cache_detail *cd) 723{ 724 struct cache_reader *rp = filp->private_data; 725 struct cache_request *rq; 726 struct inode *inode = filp->f_path.dentry->d_inode; 727 int err; 728 729 if (count == 0) 730 return 0; 731 732 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent 733 * readers on this file */ 734 again: 735 spin_lock(&queue_lock); 736 /* need to find next request */ 737 while (rp->q.list.next != &cd->queue && 738 list_entry(rp->q.list.next, struct cache_queue, list) 739 ->reader) { 740 struct list_head *next = rp->q.list.next; 741 list_move(&rp->q.list, next); 742 } 743 if (rp->q.list.next == &cd->queue) { 744 spin_unlock(&queue_lock); 745 mutex_unlock(&inode->i_mutex); 746 BUG_ON(rp->offset); 747 return 0; 748 } 749 rq = container_of(rp->q.list.next, struct cache_request, q.list); 750 BUG_ON(rq->q.reader); 751 if (rp->offset == 0) 752 rq->readers++; 753 spin_unlock(&queue_lock); 754 755 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { 756 err = -EAGAIN; 757 spin_lock(&queue_lock); 758 list_move(&rp->q.list, &rq->q.list); 759 spin_unlock(&queue_lock); 760 } else { 761 if (rp->offset + count > rq->len) 762 count = rq->len - rp->offset; 763 err = -EFAULT; 764 if (copy_to_user(buf, rq->buf + rp->offset, count)) 765 goto out; 766 rp->offset += count; 767 if (rp->offset >= rq->len) { 768 rp->offset = 0; 769 spin_lock(&queue_lock); 770 list_move(&rp->q.list, &rq->q.list); 771 spin_unlock(&queue_lock); 772 } 773 err = 0; 774 } 775 out: 776 if (rp->offset == 0) { 777 /* need to release rq */ 778 spin_lock(&queue_lock); 779 rq->readers--; 780 if (rq->readers == 0 && 781 !test_bit(CACHE_PENDING, &rq->item->flags)) { 782 list_del(&rq->q.list); 783 spin_unlock(&queue_lock); 784 cache_put(rq->item, cd); 785 kfree(rq->buf); 786 kfree(rq); 787 } else 788 spin_unlock(&queue_lock); 789 } 790 if (err == -EAGAIN) 791 goto again; 792 mutex_unlock(&inode->i_mutex); 793 return err ? err : count; 794} 795 796static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, 797 size_t count, struct cache_detail *cd) 798{ 799 ssize_t ret; 800 801 if (copy_from_user(kaddr, buf, count)) 802 return -EFAULT; 803 kaddr[count] = '\0'; 804 ret = cd->cache_parse(cd, kaddr, count); 805 if (!ret) 806 ret = count; 807 return ret; 808} 809 810static ssize_t cache_slow_downcall(const char __user *buf, 811 size_t count, struct cache_detail *cd) 812{ 813 static char write_buf[8192]; /* protected by queue_io_mutex */ 814 ssize_t ret = -EINVAL; 815 816 if (count >= sizeof(write_buf)) 817 goto out; 818 mutex_lock(&queue_io_mutex); 819 ret = cache_do_downcall(write_buf, buf, count, cd); 820 mutex_unlock(&queue_io_mutex); 821out: 822 return ret; 823} 824 825static ssize_t cache_downcall(struct address_space *mapping, 826 const char __user *buf, 827 size_t count, struct cache_detail *cd) 828{ 829 struct page *page; 830 char *kaddr; 831 ssize_t ret = -ENOMEM; 832 833 if (count >= PAGE_CACHE_SIZE) 834 goto out_slow; 835 836 page = find_or_create_page(mapping, 0, GFP_KERNEL); 837 if (!page) 838 goto out_slow; 839 840 kaddr = kmap(page); 841 ret = cache_do_downcall(kaddr, buf, count, cd); 842 kunmap(page); 843 unlock_page(page); 844 page_cache_release(page); 845 return ret; 846out_slow: 847 return cache_slow_downcall(buf, count, cd); 848} 849 850static ssize_t cache_write(struct file *filp, const char __user *buf, 851 size_t count, loff_t *ppos, 852 struct cache_detail *cd) 853{ 854 struct address_space *mapping = filp->f_mapping; 855 struct inode *inode = filp->f_path.dentry->d_inode; 856 ssize_t ret = -EINVAL; 857 858 if (!cd->cache_parse) 859 goto out; 860 861 mutex_lock(&inode->i_mutex); 862 ret = cache_downcall(mapping, buf, count, cd); 863 mutex_unlock(&inode->i_mutex); 864out: 865 return ret; 866} 867 868static DECLARE_WAIT_QUEUE_HEAD(queue_wait); 869 870static unsigned int cache_poll(struct file *filp, poll_table *wait, 871 struct cache_detail *cd) 872{ 873 unsigned int mask; 874 struct cache_reader *rp = filp->private_data; 875 struct cache_queue *cq; 876 877 poll_wait(filp, &queue_wait, wait); 878 879 /* alway allow write */ 880 mask = POLL_OUT | POLLWRNORM; 881 882 if (!rp) 883 return mask; 884 885 spin_lock(&queue_lock); 886 887 for (cq= &rp->q; &cq->list != &cd->queue; 888 cq = list_entry(cq->list.next, struct cache_queue, list)) 889 if (!cq->reader) { 890 mask |= POLLIN | POLLRDNORM; 891 break; 892 } 893 spin_unlock(&queue_lock); 894 return mask; 895} 896 897static int cache_ioctl(struct inode *ino, struct file *filp, 898 unsigned int cmd, unsigned long arg, 899 struct cache_detail *cd) 900{ 901 int len = 0; 902 struct cache_reader *rp = filp->private_data; 903 struct cache_queue *cq; 904 905 if (cmd != FIONREAD || !rp) 906 return -EINVAL; 907 908 spin_lock(&queue_lock); 909 910 /* only find the length remaining in current request, 911 * or the length of the next request 912 */ 913 for (cq= &rp->q; &cq->list != &cd->queue; 914 cq = list_entry(cq->list.next, struct cache_queue, list)) 915 if (!cq->reader) { 916 struct cache_request *cr = 917 container_of(cq, struct cache_request, q); 918 len = cr->len - rp->offset; 919 break; 920 } 921 spin_unlock(&queue_lock); 922 923 return put_user(len, (int __user *)arg); 924} 925 926static int cache_open(struct inode *inode, struct file *filp, 927 struct cache_detail *cd) 928{ 929 struct cache_reader *rp = NULL; 930 931 if (!cd || !try_module_get(cd->owner)) 932 return -EACCES; 933 nonseekable_open(inode, filp); 934 if (filp->f_mode & FMODE_READ) { 935 rp = kmalloc(sizeof(*rp), GFP_KERNEL); 936 if (!rp) 937 return -ENOMEM; 938 rp->offset = 0; 939 rp->q.reader = 1; 940 atomic_inc(&cd->readers); 941 spin_lock(&queue_lock); 942 list_add(&rp->q.list, &cd->queue); 943 spin_unlock(&queue_lock); 944 } 945 filp->private_data = rp; 946 return 0; 947} 948 949static int cache_release(struct inode *inode, struct file *filp, 950 struct cache_detail *cd) 951{ 952 struct cache_reader *rp = filp->private_data; 953 954 if (rp) { 955 spin_lock(&queue_lock); 956 if (rp->offset) { 957 struct cache_queue *cq; 958 for (cq= &rp->q; &cq->list != &cd->queue; 959 cq = list_entry(cq->list.next, struct cache_queue, list)) 960 if (!cq->reader) { 961 container_of(cq, struct cache_request, q) 962 ->readers--; 963 break; 964 } 965 rp->offset = 0; 966 } 967 list_del(&rp->q.list); 968 spin_unlock(&queue_lock); 969 970 filp->private_data = NULL; 971 kfree(rp); 972 973 cd->last_close = seconds_since_boot(); 974 atomic_dec(&cd->readers); 975 } 976 module_put(cd->owner); 977 return 0; 978} 979 980 981 982static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) 983{ 984 struct cache_queue *cq; 985 spin_lock(&queue_lock); 986 list_for_each_entry(cq, &detail->queue, list) 987 if (!cq->reader) { 988 struct cache_request *cr = container_of(cq, struct cache_request, q); 989 if (cr->item != ch) 990 continue; 991 if (cr->readers != 0) 992 continue; 993 list_del(&cr->q.list); 994 spin_unlock(&queue_lock); 995 cache_put(cr->item, detail); 996 kfree(cr->buf); 997 kfree(cr); 998 return; 999 } 1000 spin_unlock(&queue_lock); 1001} 1002 1003/* 1004 * Support routines for text-based upcalls. 1005 * Fields are separated by spaces. 1006 * Fields are either mangled to quote space tab newline slosh with slosh 1007 * or a hexified with a leading \x 1008 * Record is terminated with newline. 1009 * 1010 */ 1011 1012void qword_add(char **bpp, int *lp, char *str) 1013{ 1014 char *bp = *bpp; 1015 int len = *lp; 1016 char c; 1017 1018 if (len < 0) return; 1019 1020 while ((c=*str++) && len) 1021 switch(c) { 1022 case ' ': 1023 case '\t': 1024 case '\n': 1025 case '\\': 1026 if (len >= 4) { 1027 *bp++ = '\\'; 1028 *bp++ = '0' + ((c & 0300)>>6); 1029 *bp++ = '0' + ((c & 0070)>>3); 1030 *bp++ = '0' + ((c & 0007)>>0); 1031 } 1032 len -= 4; 1033 break; 1034 default: 1035 *bp++ = c; 1036 len--; 1037 } 1038 if (c || len <1) len = -1; 1039 else { 1040 *bp++ = ' '; 1041 len--; 1042 } 1043 *bpp = bp; 1044 *lp = len; 1045} 1046EXPORT_SYMBOL_GPL(qword_add); 1047 1048void qword_addhex(char **bpp, int *lp, char *buf, int blen) 1049{ 1050 char *bp = *bpp; 1051 int len = *lp; 1052 1053 if (len < 0) return; 1054 1055 if (len > 2) { 1056 *bp++ = '\\'; 1057 *bp++ = 'x'; 1058 len -= 2; 1059 while (blen && len >= 2) { 1060 unsigned char c = *buf++; 1061 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 1062 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 1063 len -= 2; 1064 blen--; 1065 } 1066 } 1067 if (blen || len<1) len = -1; 1068 else { 1069 *bp++ = ' '; 1070 len--; 1071 } 1072 *bpp = bp; 1073 *lp = len; 1074} 1075EXPORT_SYMBOL_GPL(qword_addhex); 1076 1077static void warn_no_listener(struct cache_detail *detail) 1078{ 1079 if (detail->last_warn != detail->last_close) { 1080 detail->last_warn = detail->last_close; 1081 if (detail->warn_no_listener) 1082 detail->warn_no_listener(detail, detail->last_close != 0); 1083 } 1084} 1085 1086static bool cache_listeners_exist(struct cache_detail *detail) 1087{ 1088 if (atomic_read(&detail->readers)) 1089 return true; 1090 if (detail->last_close == 0) 1091 /* This cache was never opened */ 1092 return false; 1093 if (detail->last_close < seconds_since_boot() - 30) 1094 /* 1095 * We allow for the possibility that someone might 1096 * restart a userspace daemon without restarting the 1097 * server; but after 30 seconds, we give up. 1098 */ 1099 return false; 1100 return true; 1101} 1102 1103/* 1104 * register an upcall request to user-space and queue it up for read() by the 1105 * upcall daemon. 1106 * 1107 * Each request is at most one page long. 1108 */ 1109int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, 1110 void (*cache_request)(struct cache_detail *, 1111 struct cache_head *, 1112 char **, 1113 int *)) 1114{ 1115 1116 char *buf; 1117 struct cache_request *crq; 1118 char *bp; 1119 int len; 1120 1121 if (!cache_listeners_exist(detail)) { 1122 warn_no_listener(detail); 1123 return -EINVAL; 1124 } 1125 1126 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 1127 if (!buf) 1128 return -EAGAIN; 1129 1130 crq = kmalloc(sizeof (*crq), GFP_KERNEL); 1131 if (!crq) { 1132 kfree(buf); 1133 return -EAGAIN; 1134 } 1135 1136 bp = buf; len = PAGE_SIZE; 1137 1138 cache_request(detail, h, &bp, &len); 1139 1140 if (len < 0) { 1141 kfree(buf); 1142 kfree(crq); 1143 return -EAGAIN; 1144 } 1145 crq->q.reader = 0; 1146 crq->item = cache_get(h); 1147 crq->buf = buf; 1148 crq->len = PAGE_SIZE - len; 1149 crq->readers = 0; 1150 spin_lock(&queue_lock); 1151 list_add_tail(&crq->q.list, &detail->queue); 1152 spin_unlock(&queue_lock); 1153 wake_up(&queue_wait); 1154 return 0; 1155} 1156EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); 1157 1158/* 1159 * parse a message from user-space and pass it 1160 * to an appropriate cache 1161 * Messages are, like requests, separated into fields by 1162 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal 1163 * 1164 * Message is 1165 * reply cachename expiry key ... content.... 1166 * 1167 * key and content are both parsed by cache 1168 */ 1169 1170#define isodigit(c) (isdigit(c) && c <= '7') 1171int qword_get(char **bpp, char *dest, int bufsize) 1172{ 1173 /* return bytes copied, or -1 on error */ 1174 char *bp = *bpp; 1175 int len = 0; 1176 1177 while (*bp == ' ') bp++; 1178 1179 if (bp[0] == '\\' && bp[1] == 'x') { 1180 /* HEX STRING */ 1181 bp += 2; 1182 while (len < bufsize) { 1183 int h, l; 1184 1185 h = hex_to_bin(bp[0]); 1186 if (h < 0) 1187 break; 1188 1189 l = hex_to_bin(bp[1]); 1190 if (l < 0) 1191 break; 1192 1193 *dest++ = (h << 4) | l; 1194 bp += 2; 1195 len++; 1196 } 1197 } else { 1198 /* text with \nnn octal quoting */ 1199 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { 1200 if (*bp == '\\' && 1201 isodigit(bp[1]) && (bp[1] <= '3') && 1202 isodigit(bp[2]) && 1203 isodigit(bp[3])) { 1204 int byte = (*++bp -'0'); 1205 bp++; 1206 byte = (byte << 3) | (*bp++ - '0'); 1207 byte = (byte << 3) | (*bp++ - '0'); 1208 *dest++ = byte; 1209 len++; 1210 } else { 1211 *dest++ = *bp++; 1212 len++; 1213 } 1214 } 1215 } 1216 1217 if (*bp != ' ' && *bp != '\n' && *bp != '\0') 1218 return -1; 1219 while (*bp == ' ') bp++; 1220 *bpp = bp; 1221 *dest = '\0'; 1222 return len; 1223} 1224EXPORT_SYMBOL_GPL(qword_get); 1225 1226 1227/* 1228 * support /proc/sunrpc/cache/$CACHENAME/content 1229 * as a seqfile. 1230 * We call ->cache_show passing NULL for the item to 1231 * get a header, then pass each real item in the cache 1232 */ 1233 1234struct handle { 1235 struct cache_detail *cd; 1236}; 1237 1238static void *c_start(struct seq_file *m, loff_t *pos) 1239 __acquires(cd->hash_lock) 1240{ 1241 loff_t n = *pos; 1242 unsigned hash, entry; 1243 struct cache_head *ch; 1244 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1245 1246 1247 read_lock(&cd->hash_lock); 1248 if (!n--) 1249 return SEQ_START_TOKEN; 1250 hash = n >> 32; 1251 entry = n & ((1LL<<32) - 1); 1252 1253 for (ch=cd->hash_table[hash]; ch; ch=ch->next) 1254 if (!entry--) 1255 return ch; 1256 n &= ~((1LL<<32) - 1); 1257 do { 1258 hash++; 1259 n += 1LL<<32; 1260 } while(hash < cd->hash_size && 1261 cd->hash_table[hash]==NULL); 1262 if (hash >= cd->hash_size) 1263 return NULL; 1264 *pos = n+1; 1265 return cd->hash_table[hash]; 1266} 1267 1268static void *c_next(struct seq_file *m, void *p, loff_t *pos) 1269{ 1270 struct cache_head *ch = p; 1271 int hash = (*pos >> 32); 1272 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1273 1274 if (p == SEQ_START_TOKEN) 1275 hash = 0; 1276 else if (ch->next == NULL) { 1277 hash++; 1278 *pos += 1LL<<32; 1279 } else { 1280 ++*pos; 1281 return ch->next; 1282 } 1283 *pos &= ~((1LL<<32) - 1); 1284 while (hash < cd->hash_size && 1285 cd->hash_table[hash] == NULL) { 1286 hash++; 1287 *pos += 1LL<<32; 1288 } 1289 if (hash >= cd->hash_size) 1290 return NULL; 1291 ++*pos; 1292 return cd->hash_table[hash]; 1293} 1294 1295static void c_stop(struct seq_file *m, void *p) 1296 __releases(cd->hash_lock) 1297{ 1298 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1299 read_unlock(&cd->hash_lock); 1300} 1301 1302static int c_show(struct seq_file *m, void *p) 1303{ 1304 struct cache_head *cp = p; 1305 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1306 1307 if (p == SEQ_START_TOKEN) 1308 return cd->cache_show(m, cd, NULL); 1309 1310 ifdebug(CACHE) 1311 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", 1312 convert_to_wallclock(cp->expiry_time), 1313 atomic_read(&cp->ref.refcount), cp->flags); 1314 cache_get(cp); 1315 if (cache_check(cd, cp, NULL)) 1316 /* cache_check does a cache_put on failure */ 1317 seq_printf(m, "# "); 1318 else 1319 cache_put(cp, cd); 1320 1321 return cd->cache_show(m, cd, cp); 1322} 1323 1324static const struct seq_operations cache_content_op = { 1325 .start = c_start, 1326 .next = c_next, 1327 .stop = c_stop, 1328 .show = c_show, 1329}; 1330 1331static int content_open(struct inode *inode, struct file *file, 1332 struct cache_detail *cd) 1333{ 1334 struct handle *han; 1335 1336 if (!cd || !try_module_get(cd->owner)) 1337 return -EACCES; 1338 han = __seq_open_private(file, &cache_content_op, sizeof(*han)); 1339 if (han == NULL) { 1340 module_put(cd->owner); 1341 return -ENOMEM; 1342 } 1343 1344 han->cd = cd; 1345 return 0; 1346} 1347 1348static int content_release(struct inode *inode, struct file *file, 1349 struct cache_detail *cd) 1350{ 1351 int ret = seq_release_private(inode, file); 1352 module_put(cd->owner); 1353 return ret; 1354} 1355 1356static int open_flush(struct inode *inode, struct file *file, 1357 struct cache_detail *cd) 1358{ 1359 if (!cd || !try_module_get(cd->owner)) 1360 return -EACCES; 1361 return nonseekable_open(inode, file); 1362} 1363 1364static int release_flush(struct inode *inode, struct file *file, 1365 struct cache_detail *cd) 1366{ 1367 module_put(cd->owner); 1368 return 0; 1369} 1370 1371static ssize_t read_flush(struct file *file, char __user *buf, 1372 size_t count, loff_t *ppos, 1373 struct cache_detail *cd) 1374{ 1375 char tbuf[20]; 1376 unsigned long p = *ppos; 1377 size_t len; 1378 1379 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time)); 1380 len = strlen(tbuf); 1381 if (p >= len) 1382 return 0; 1383 len -= p; 1384 if (len > count) 1385 len = count; 1386 if (copy_to_user(buf, (void*)(tbuf+p), len)) 1387 return -EFAULT; 1388 *ppos += len; 1389 return len; 1390} 1391 1392static ssize_t write_flush(struct file *file, const char __user *buf, 1393 size_t count, loff_t *ppos, 1394 struct cache_detail *cd) 1395{ 1396 char tbuf[20]; 1397 char *bp, *ep; 1398 1399 if (*ppos || count > sizeof(tbuf)-1) 1400 return -EINVAL; 1401 if (copy_from_user(tbuf, buf, count)) 1402 return -EFAULT; 1403 tbuf[count] = 0; 1404 simple_strtoul(tbuf, &ep, 0); 1405 if (*ep && *ep != '\n') 1406 return -EINVAL; 1407 1408 bp = tbuf; 1409 cd->flush_time = get_expiry(&bp); 1410 cd->nextcheck = seconds_since_boot(); 1411 cache_flush(); 1412 1413 *ppos += count; 1414 return count; 1415} 1416 1417static ssize_t cache_read_procfs(struct file *filp, char __user *buf, 1418 size_t count, loff_t *ppos) 1419{ 1420 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1421 1422 return cache_read(filp, buf, count, ppos, cd); 1423} 1424 1425static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, 1426 size_t count, loff_t *ppos) 1427{ 1428 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1429 1430 return cache_write(filp, buf, count, ppos, cd); 1431} 1432 1433static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) 1434{ 1435 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1436 1437 return cache_poll(filp, wait, cd); 1438} 1439 1440static long cache_ioctl_procfs(struct file *filp, 1441 unsigned int cmd, unsigned long arg) 1442{ 1443 long ret; 1444 struct inode *inode = filp->f_path.dentry->d_inode; 1445 struct cache_detail *cd = PDE(inode)->data; 1446 1447 lock_kernel(); 1448 ret = cache_ioctl(inode, filp, cmd, arg, cd); 1449 unlock_kernel(); 1450 1451 return ret; 1452} 1453 1454static int cache_open_procfs(struct inode *inode, struct file *filp) 1455{ 1456 struct cache_detail *cd = PDE(inode)->data; 1457 1458 return cache_open(inode, filp, cd); 1459} 1460 1461static int cache_release_procfs(struct inode *inode, struct file *filp) 1462{ 1463 struct cache_detail *cd = PDE(inode)->data; 1464 1465 return cache_release(inode, filp, cd); 1466} 1467 1468static const struct file_operations cache_file_operations_procfs = { 1469 .owner = THIS_MODULE, 1470 .llseek = no_llseek, 1471 .read = cache_read_procfs, 1472 .write = cache_write_procfs, 1473 .poll = cache_poll_procfs, 1474 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ 1475 .open = cache_open_procfs, 1476 .release = cache_release_procfs, 1477}; 1478 1479static int content_open_procfs(struct inode *inode, struct file *filp) 1480{ 1481 struct cache_detail *cd = PDE(inode)->data; 1482 1483 return content_open(inode, filp, cd); 1484} 1485 1486static int content_release_procfs(struct inode *inode, struct file *filp) 1487{ 1488 struct cache_detail *cd = PDE(inode)->data; 1489 1490 return content_release(inode, filp, cd); 1491} 1492 1493static const struct file_operations content_file_operations_procfs = { 1494 .open = content_open_procfs, 1495 .read = seq_read, 1496 .llseek = seq_lseek, 1497 .release = content_release_procfs, 1498}; 1499 1500static int open_flush_procfs(struct inode *inode, struct file *filp) 1501{ 1502 struct cache_detail *cd = PDE(inode)->data; 1503 1504 return open_flush(inode, filp, cd); 1505} 1506 1507static int release_flush_procfs(struct inode *inode, struct file *filp) 1508{ 1509 struct cache_detail *cd = PDE(inode)->data; 1510 1511 return release_flush(inode, filp, cd); 1512} 1513 1514static ssize_t read_flush_procfs(struct file *filp, char __user *buf, 1515 size_t count, loff_t *ppos) 1516{ 1517 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1518 1519 return read_flush(filp, buf, count, ppos, cd); 1520} 1521 1522static ssize_t write_flush_procfs(struct file *filp, 1523 const char __user *buf, 1524 size_t count, loff_t *ppos) 1525{ 1526 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1527 1528 return write_flush(filp, buf, count, ppos, cd); 1529} 1530 1531static const struct file_operations cache_flush_operations_procfs = { 1532 .open = open_flush_procfs, 1533 .read = read_flush_procfs, 1534 .write = write_flush_procfs, 1535 .release = release_flush_procfs, 1536}; 1537 1538static void remove_cache_proc_entries(struct cache_detail *cd) 1539{ 1540 if (cd->u.procfs.proc_ent == NULL) 1541 return; 1542 if (cd->u.procfs.flush_ent) 1543 remove_proc_entry("flush", cd->u.procfs.proc_ent); 1544 if (cd->u.procfs.channel_ent) 1545 remove_proc_entry("channel", cd->u.procfs.proc_ent); 1546 if (cd->u.procfs.content_ent) 1547 remove_proc_entry("content", cd->u.procfs.proc_ent); 1548 cd->u.procfs.proc_ent = NULL; 1549 remove_proc_entry(cd->name, proc_net_rpc); 1550} 1551 1552#ifdef CONFIG_PROC_FS 1553static int create_cache_proc_entries(struct cache_detail *cd) 1554{ 1555 struct proc_dir_entry *p; 1556 1557 cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc); 1558 if (cd->u.procfs.proc_ent == NULL) 1559 goto out_nomem; 1560 cd->u.procfs.channel_ent = NULL; 1561 cd->u.procfs.content_ent = NULL; 1562 1563 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, 1564 cd->u.procfs.proc_ent, 1565 &cache_flush_operations_procfs, cd); 1566 cd->u.procfs.flush_ent = p; 1567 if (p == NULL) 1568 goto out_nomem; 1569 1570 if (cd->cache_upcall || cd->cache_parse) { 1571 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, 1572 cd->u.procfs.proc_ent, 1573 &cache_file_operations_procfs, cd); 1574 cd->u.procfs.channel_ent = p; 1575 if (p == NULL) 1576 goto out_nomem; 1577 } 1578 if (cd->cache_show) { 1579 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, 1580 cd->u.procfs.proc_ent, 1581 &content_file_operations_procfs, cd); 1582 cd->u.procfs.content_ent = p; 1583 if (p == NULL) 1584 goto out_nomem; 1585 } 1586 return 0; 1587out_nomem: 1588 remove_cache_proc_entries(cd); 1589 return -ENOMEM; 1590} 1591#else /* CONFIG_PROC_FS */ 1592static int create_cache_proc_entries(struct cache_detail *cd) 1593{ 1594 return 0; 1595} 1596#endif 1597 1598void __init cache_initialize(void) 1599{ 1600 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean); 1601} 1602 1603int cache_register(struct cache_detail *cd) 1604{ 1605 int ret; 1606 1607 sunrpc_init_cache_detail(cd); 1608 ret = create_cache_proc_entries(cd); 1609 if (ret) 1610 sunrpc_destroy_cache_detail(cd); 1611 return ret; 1612} 1613EXPORT_SYMBOL_GPL(cache_register); 1614 1615void cache_unregister(struct cache_detail *cd) 1616{ 1617 remove_cache_proc_entries(cd); 1618 sunrpc_destroy_cache_detail(cd); 1619} 1620EXPORT_SYMBOL_GPL(cache_unregister); 1621 1622static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, 1623 size_t count, loff_t *ppos) 1624{ 1625 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1626 1627 return cache_read(filp, buf, count, ppos, cd); 1628} 1629 1630static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, 1631 size_t count, loff_t *ppos) 1632{ 1633 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1634 1635 return cache_write(filp, buf, count, ppos, cd); 1636} 1637 1638static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) 1639{ 1640 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1641 1642 return cache_poll(filp, wait, cd); 1643} 1644 1645static long cache_ioctl_pipefs(struct file *filp, 1646 unsigned int cmd, unsigned long arg) 1647{ 1648 struct inode *inode = filp->f_dentry->d_inode; 1649 struct cache_detail *cd = RPC_I(inode)->private; 1650 long ret; 1651 1652 lock_kernel(); 1653 ret = cache_ioctl(inode, filp, cmd, arg, cd); 1654 unlock_kernel(); 1655 1656 return ret; 1657} 1658 1659static int cache_open_pipefs(struct inode *inode, struct file *filp) 1660{ 1661 struct cache_detail *cd = RPC_I(inode)->private; 1662 1663 return cache_open(inode, filp, cd); 1664} 1665 1666static int cache_release_pipefs(struct inode *inode, struct file *filp) 1667{ 1668 struct cache_detail *cd = RPC_I(inode)->private; 1669 1670 return cache_release(inode, filp, cd); 1671} 1672 1673const struct file_operations cache_file_operations_pipefs = { 1674 .owner = THIS_MODULE, 1675 .llseek = no_llseek, 1676 .read = cache_read_pipefs, 1677 .write = cache_write_pipefs, 1678 .poll = cache_poll_pipefs, 1679 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ 1680 .open = cache_open_pipefs, 1681 .release = cache_release_pipefs, 1682}; 1683 1684static int content_open_pipefs(struct inode *inode, struct file *filp) 1685{ 1686 struct cache_detail *cd = RPC_I(inode)->private; 1687 1688 return content_open(inode, filp, cd); 1689} 1690 1691static int content_release_pipefs(struct inode *inode, struct file *filp) 1692{ 1693 struct cache_detail *cd = RPC_I(inode)->private; 1694 1695 return content_release(inode, filp, cd); 1696} 1697 1698const struct file_operations content_file_operations_pipefs = { 1699 .open = content_open_pipefs, 1700 .read = seq_read, 1701 .llseek = seq_lseek, 1702 .release = content_release_pipefs, 1703}; 1704 1705static int open_flush_pipefs(struct inode *inode, struct file *filp) 1706{ 1707 struct cache_detail *cd = RPC_I(inode)->private; 1708 1709 return open_flush(inode, filp, cd); 1710} 1711 1712static int release_flush_pipefs(struct inode *inode, struct file *filp) 1713{ 1714 struct cache_detail *cd = RPC_I(inode)->private; 1715 1716 return release_flush(inode, filp, cd); 1717} 1718 1719static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, 1720 size_t count, loff_t *ppos) 1721{ 1722 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1723 1724 return read_flush(filp, buf, count, ppos, cd); 1725} 1726 1727static ssize_t write_flush_pipefs(struct file *filp, 1728 const char __user *buf, 1729 size_t count, loff_t *ppos) 1730{ 1731 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1732 1733 return write_flush(filp, buf, count, ppos, cd); 1734} 1735 1736const struct file_operations cache_flush_operations_pipefs = { 1737 .open = open_flush_pipefs, 1738 .read = read_flush_pipefs, 1739 .write = write_flush_pipefs, 1740 .release = release_flush_pipefs, 1741}; 1742 1743int sunrpc_cache_register_pipefs(struct dentry *parent, 1744 const char *name, mode_t umode, 1745 struct cache_detail *cd) 1746{ 1747 struct qstr q; 1748 struct dentry *dir; 1749 int ret = 0; 1750 1751 sunrpc_init_cache_detail(cd); 1752 q.name = name; 1753 q.len = strlen(name); 1754 q.hash = full_name_hash(q.name, q.len); 1755 dir = rpc_create_cache_dir(parent, &q, umode, cd); 1756 if (!IS_ERR(dir)) 1757 cd->u.pipefs.dir = dir; 1758 else { 1759 sunrpc_destroy_cache_detail(cd); 1760 ret = PTR_ERR(dir); 1761 } 1762 return ret; 1763} 1764EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); 1765 1766void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) 1767{ 1768 rpc_remove_cache_dir(cd->u.pipefs.dir); 1769 cd->u.pipefs.dir = NULL; 1770 sunrpc_destroy_cache_detail(cd); 1771} 1772EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); 1773 1774