cache.c revision f16b6e8d838b2e2bb4561201311c66ac02ad67df
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 512struct thread_deferred_req { 513 struct cache_deferred_req handle; 514 struct completion completion; 515}; 516static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) 517{ 518 struct thread_deferred_req *dr = 519 container_of(dreq, struct thread_deferred_req, handle); 520 complete(&dr->completion); 521} 522 523static int cache_defer_req(struct cache_req *req, struct cache_head *item) 524{ 525 struct cache_deferred_req *dreq, *discard; 526 int hash = DFR_HASH(item); 527 struct thread_deferred_req sleeper; 528 529 if (cache_defer_cnt >= DFR_MAX) { 530 /* too much in the cache, randomly drop this one, 531 * or continue and drop the oldest below 532 */ 533 if (net_random()&1) 534 return -ENOMEM; 535 } 536 if (req->thread_wait) { 537 dreq = &sleeper.handle; 538 sleeper.completion = 539 COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); 540 dreq->revisit = cache_restart_thread; 541 } else 542 dreq = req->defer(req); 543 544 retry: 545 if (dreq == NULL) 546 return -ENOMEM; 547 548 dreq->item = item; 549 550 spin_lock(&cache_defer_lock); 551 552 list_add(&dreq->recent, &cache_defer_list); 553 554 if (cache_defer_hash[hash].next == NULL) 555 INIT_LIST_HEAD(&cache_defer_hash[hash]); 556 list_add(&dreq->hash, &cache_defer_hash[hash]); 557 558 /* it is in, now maybe clean up */ 559 discard = NULL; 560 if (++cache_defer_cnt > DFR_MAX) { 561 discard = list_entry(cache_defer_list.prev, 562 struct cache_deferred_req, recent); 563 list_del_init(&discard->recent); 564 list_del_init(&discard->hash); 565 cache_defer_cnt--; 566 } 567 spin_unlock(&cache_defer_lock); 568 569 if (discard) 570 /* there was one too many */ 571 discard->revisit(discard, 1); 572 573 if (!test_bit(CACHE_PENDING, &item->flags)) { 574 /* must have just been validated... */ 575 cache_revisit_request(item); 576 return -EAGAIN; 577 } 578 579 if (dreq == &sleeper.handle) { 580 if (wait_for_completion_interruptible_timeout( 581 &sleeper.completion, req->thread_wait) <= 0) { 582 /* The completion wasn't completed, so we need 583 * to clean up 584 */ 585 spin_lock(&cache_defer_lock); 586 if (!list_empty(&sleeper.handle.hash)) { 587 list_del_init(&sleeper.handle.recent); 588 list_del_init(&sleeper.handle.hash); 589 cache_defer_cnt--; 590 spin_unlock(&cache_defer_lock); 591 } else { 592 /* cache_revisit_request already removed 593 * this from the hash table, but hasn't 594 * called ->revisit yet. It will very soon 595 * and we need to wait for it. 596 */ 597 spin_unlock(&cache_defer_lock); 598 wait_for_completion(&sleeper.completion); 599 } 600 } 601 if (test_bit(CACHE_PENDING, &item->flags)) { 602 /* item is still pending, try request 603 * deferral 604 */ 605 dreq = req->defer(req); 606 goto retry; 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 return 0; 616} 617 618static void cache_revisit_request(struct cache_head *item) 619{ 620 struct cache_deferred_req *dreq; 621 struct list_head pending; 622 623 struct list_head *lp; 624 int hash = DFR_HASH(item); 625 626 INIT_LIST_HEAD(&pending); 627 spin_lock(&cache_defer_lock); 628 629 lp = cache_defer_hash[hash].next; 630 if (lp) { 631 while (lp != &cache_defer_hash[hash]) { 632 dreq = list_entry(lp, struct cache_deferred_req, hash); 633 lp = lp->next; 634 if (dreq->item == item) { 635 list_del_init(&dreq->hash); 636 list_move(&dreq->recent, &pending); 637 cache_defer_cnt--; 638 } 639 } 640 } 641 spin_unlock(&cache_defer_lock); 642 643 while (!list_empty(&pending)) { 644 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 645 list_del_init(&dreq->recent); 646 dreq->revisit(dreq, 0); 647 } 648} 649 650void cache_clean_deferred(void *owner) 651{ 652 struct cache_deferred_req *dreq, *tmp; 653 struct list_head pending; 654 655 656 INIT_LIST_HEAD(&pending); 657 spin_lock(&cache_defer_lock); 658 659 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { 660 if (dreq->owner == owner) { 661 list_del_init(&dreq->hash); 662 list_move(&dreq->recent, &pending); 663 cache_defer_cnt--; 664 } 665 } 666 spin_unlock(&cache_defer_lock); 667 668 while (!list_empty(&pending)) { 669 dreq = list_entry(pending.next, struct cache_deferred_req, recent); 670 list_del_init(&dreq->recent); 671 dreq->revisit(dreq, 1); 672 } 673} 674 675/* 676 * communicate with user-space 677 * 678 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. 679 * On read, you get a full request, or block. 680 * On write, an update request is processed. 681 * Poll works if anything to read, and always allows write. 682 * 683 * Implemented by linked list of requests. Each open file has 684 * a ->private that also exists in this list. New requests are added 685 * to the end and may wakeup and preceding readers. 686 * New readers are added to the head. If, on read, an item is found with 687 * CACHE_UPCALLING clear, we free it from the list. 688 * 689 */ 690 691static DEFINE_SPINLOCK(queue_lock); 692static DEFINE_MUTEX(queue_io_mutex); 693 694struct cache_queue { 695 struct list_head list; 696 int reader; /* if 0, then request */ 697}; 698struct cache_request { 699 struct cache_queue q; 700 struct cache_head *item; 701 char * buf; 702 int len; 703 int readers; 704}; 705struct cache_reader { 706 struct cache_queue q; 707 int offset; /* if non-0, we have a refcnt on next request */ 708}; 709 710static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, 711 loff_t *ppos, struct cache_detail *cd) 712{ 713 struct cache_reader *rp = filp->private_data; 714 struct cache_request *rq; 715 struct inode *inode = filp->f_path.dentry->d_inode; 716 int err; 717 718 if (count == 0) 719 return 0; 720 721 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent 722 * readers on this file */ 723 again: 724 spin_lock(&queue_lock); 725 /* need to find next request */ 726 while (rp->q.list.next != &cd->queue && 727 list_entry(rp->q.list.next, struct cache_queue, list) 728 ->reader) { 729 struct list_head *next = rp->q.list.next; 730 list_move(&rp->q.list, next); 731 } 732 if (rp->q.list.next == &cd->queue) { 733 spin_unlock(&queue_lock); 734 mutex_unlock(&inode->i_mutex); 735 BUG_ON(rp->offset); 736 return 0; 737 } 738 rq = container_of(rp->q.list.next, struct cache_request, q.list); 739 BUG_ON(rq->q.reader); 740 if (rp->offset == 0) 741 rq->readers++; 742 spin_unlock(&queue_lock); 743 744 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { 745 err = -EAGAIN; 746 spin_lock(&queue_lock); 747 list_move(&rp->q.list, &rq->q.list); 748 spin_unlock(&queue_lock); 749 } else { 750 if (rp->offset + count > rq->len) 751 count = rq->len - rp->offset; 752 err = -EFAULT; 753 if (copy_to_user(buf, rq->buf + rp->offset, count)) 754 goto out; 755 rp->offset += count; 756 if (rp->offset >= rq->len) { 757 rp->offset = 0; 758 spin_lock(&queue_lock); 759 list_move(&rp->q.list, &rq->q.list); 760 spin_unlock(&queue_lock); 761 } 762 err = 0; 763 } 764 out: 765 if (rp->offset == 0) { 766 /* need to release rq */ 767 spin_lock(&queue_lock); 768 rq->readers--; 769 if (rq->readers == 0 && 770 !test_bit(CACHE_PENDING, &rq->item->flags)) { 771 list_del(&rq->q.list); 772 spin_unlock(&queue_lock); 773 cache_put(rq->item, cd); 774 kfree(rq->buf); 775 kfree(rq); 776 } else 777 spin_unlock(&queue_lock); 778 } 779 if (err == -EAGAIN) 780 goto again; 781 mutex_unlock(&inode->i_mutex); 782 return err ? err : count; 783} 784 785static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, 786 size_t count, struct cache_detail *cd) 787{ 788 ssize_t ret; 789 790 if (copy_from_user(kaddr, buf, count)) 791 return -EFAULT; 792 kaddr[count] = '\0'; 793 ret = cd->cache_parse(cd, kaddr, count); 794 if (!ret) 795 ret = count; 796 return ret; 797} 798 799static ssize_t cache_slow_downcall(const char __user *buf, 800 size_t count, struct cache_detail *cd) 801{ 802 static char write_buf[8192]; /* protected by queue_io_mutex */ 803 ssize_t ret = -EINVAL; 804 805 if (count >= sizeof(write_buf)) 806 goto out; 807 mutex_lock(&queue_io_mutex); 808 ret = cache_do_downcall(write_buf, buf, count, cd); 809 mutex_unlock(&queue_io_mutex); 810out: 811 return ret; 812} 813 814static ssize_t cache_downcall(struct address_space *mapping, 815 const char __user *buf, 816 size_t count, struct cache_detail *cd) 817{ 818 struct page *page; 819 char *kaddr; 820 ssize_t ret = -ENOMEM; 821 822 if (count >= PAGE_CACHE_SIZE) 823 goto out_slow; 824 825 page = find_or_create_page(mapping, 0, GFP_KERNEL); 826 if (!page) 827 goto out_slow; 828 829 kaddr = kmap(page); 830 ret = cache_do_downcall(kaddr, buf, count, cd); 831 kunmap(page); 832 unlock_page(page); 833 page_cache_release(page); 834 return ret; 835out_slow: 836 return cache_slow_downcall(buf, count, cd); 837} 838 839static ssize_t cache_write(struct file *filp, const char __user *buf, 840 size_t count, loff_t *ppos, 841 struct cache_detail *cd) 842{ 843 struct address_space *mapping = filp->f_mapping; 844 struct inode *inode = filp->f_path.dentry->d_inode; 845 ssize_t ret = -EINVAL; 846 847 if (!cd->cache_parse) 848 goto out; 849 850 mutex_lock(&inode->i_mutex); 851 ret = cache_downcall(mapping, buf, count, cd); 852 mutex_unlock(&inode->i_mutex); 853out: 854 return ret; 855} 856 857static DECLARE_WAIT_QUEUE_HEAD(queue_wait); 858 859static unsigned int cache_poll(struct file *filp, poll_table *wait, 860 struct cache_detail *cd) 861{ 862 unsigned int mask; 863 struct cache_reader *rp = filp->private_data; 864 struct cache_queue *cq; 865 866 poll_wait(filp, &queue_wait, wait); 867 868 /* alway allow write */ 869 mask = POLL_OUT | POLLWRNORM; 870 871 if (!rp) 872 return mask; 873 874 spin_lock(&queue_lock); 875 876 for (cq= &rp->q; &cq->list != &cd->queue; 877 cq = list_entry(cq->list.next, struct cache_queue, list)) 878 if (!cq->reader) { 879 mask |= POLLIN | POLLRDNORM; 880 break; 881 } 882 spin_unlock(&queue_lock); 883 return mask; 884} 885 886static int cache_ioctl(struct inode *ino, struct file *filp, 887 unsigned int cmd, unsigned long arg, 888 struct cache_detail *cd) 889{ 890 int len = 0; 891 struct cache_reader *rp = filp->private_data; 892 struct cache_queue *cq; 893 894 if (cmd != FIONREAD || !rp) 895 return -EINVAL; 896 897 spin_lock(&queue_lock); 898 899 /* only find the length remaining in current request, 900 * or the length of the next request 901 */ 902 for (cq= &rp->q; &cq->list != &cd->queue; 903 cq = list_entry(cq->list.next, struct cache_queue, list)) 904 if (!cq->reader) { 905 struct cache_request *cr = 906 container_of(cq, struct cache_request, q); 907 len = cr->len - rp->offset; 908 break; 909 } 910 spin_unlock(&queue_lock); 911 912 return put_user(len, (int __user *)arg); 913} 914 915static int cache_open(struct inode *inode, struct file *filp, 916 struct cache_detail *cd) 917{ 918 struct cache_reader *rp = NULL; 919 920 if (!cd || !try_module_get(cd->owner)) 921 return -EACCES; 922 nonseekable_open(inode, filp); 923 if (filp->f_mode & FMODE_READ) { 924 rp = kmalloc(sizeof(*rp), GFP_KERNEL); 925 if (!rp) 926 return -ENOMEM; 927 rp->offset = 0; 928 rp->q.reader = 1; 929 atomic_inc(&cd->readers); 930 spin_lock(&queue_lock); 931 list_add(&rp->q.list, &cd->queue); 932 spin_unlock(&queue_lock); 933 } 934 filp->private_data = rp; 935 return 0; 936} 937 938static int cache_release(struct inode *inode, struct file *filp, 939 struct cache_detail *cd) 940{ 941 struct cache_reader *rp = filp->private_data; 942 943 if (rp) { 944 spin_lock(&queue_lock); 945 if (rp->offset) { 946 struct cache_queue *cq; 947 for (cq= &rp->q; &cq->list != &cd->queue; 948 cq = list_entry(cq->list.next, struct cache_queue, list)) 949 if (!cq->reader) { 950 container_of(cq, struct cache_request, q) 951 ->readers--; 952 break; 953 } 954 rp->offset = 0; 955 } 956 list_del(&rp->q.list); 957 spin_unlock(&queue_lock); 958 959 filp->private_data = NULL; 960 kfree(rp); 961 962 cd->last_close = seconds_since_boot(); 963 atomic_dec(&cd->readers); 964 } 965 module_put(cd->owner); 966 return 0; 967} 968 969 970 971static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) 972{ 973 struct cache_queue *cq; 974 spin_lock(&queue_lock); 975 list_for_each_entry(cq, &detail->queue, list) 976 if (!cq->reader) { 977 struct cache_request *cr = container_of(cq, struct cache_request, q); 978 if (cr->item != ch) 979 continue; 980 if (cr->readers != 0) 981 continue; 982 list_del(&cr->q.list); 983 spin_unlock(&queue_lock); 984 cache_put(cr->item, detail); 985 kfree(cr->buf); 986 kfree(cr); 987 return; 988 } 989 spin_unlock(&queue_lock); 990} 991 992/* 993 * Support routines for text-based upcalls. 994 * Fields are separated by spaces. 995 * Fields are either mangled to quote space tab newline slosh with slosh 996 * or a hexified with a leading \x 997 * Record is terminated with newline. 998 * 999 */ 1000 1001void qword_add(char **bpp, int *lp, char *str) 1002{ 1003 char *bp = *bpp; 1004 int len = *lp; 1005 char c; 1006 1007 if (len < 0) return; 1008 1009 while ((c=*str++) && len) 1010 switch(c) { 1011 case ' ': 1012 case '\t': 1013 case '\n': 1014 case '\\': 1015 if (len >= 4) { 1016 *bp++ = '\\'; 1017 *bp++ = '0' + ((c & 0300)>>6); 1018 *bp++ = '0' + ((c & 0070)>>3); 1019 *bp++ = '0' + ((c & 0007)>>0); 1020 } 1021 len -= 4; 1022 break; 1023 default: 1024 *bp++ = c; 1025 len--; 1026 } 1027 if (c || len <1) len = -1; 1028 else { 1029 *bp++ = ' '; 1030 len--; 1031 } 1032 *bpp = bp; 1033 *lp = len; 1034} 1035EXPORT_SYMBOL_GPL(qword_add); 1036 1037void qword_addhex(char **bpp, int *lp, char *buf, int blen) 1038{ 1039 char *bp = *bpp; 1040 int len = *lp; 1041 1042 if (len < 0) return; 1043 1044 if (len > 2) { 1045 *bp++ = '\\'; 1046 *bp++ = 'x'; 1047 len -= 2; 1048 while (blen && len >= 2) { 1049 unsigned char c = *buf++; 1050 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 1051 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 1052 len -= 2; 1053 blen--; 1054 } 1055 } 1056 if (blen || len<1) len = -1; 1057 else { 1058 *bp++ = ' '; 1059 len--; 1060 } 1061 *bpp = bp; 1062 *lp = len; 1063} 1064EXPORT_SYMBOL_GPL(qword_addhex); 1065 1066static void warn_no_listener(struct cache_detail *detail) 1067{ 1068 if (detail->last_warn != detail->last_close) { 1069 detail->last_warn = detail->last_close; 1070 if (detail->warn_no_listener) 1071 detail->warn_no_listener(detail, detail->last_close != 0); 1072 } 1073} 1074 1075/* 1076 * register an upcall request to user-space and queue it up for read() by the 1077 * upcall daemon. 1078 * 1079 * Each request is at most one page long. 1080 */ 1081int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, 1082 void (*cache_request)(struct cache_detail *, 1083 struct cache_head *, 1084 char **, 1085 int *)) 1086{ 1087 1088 char *buf; 1089 struct cache_request *crq; 1090 char *bp; 1091 int len; 1092 1093 if (atomic_read(&detail->readers) == 0 && 1094 detail->last_close < seconds_since_boot() - 30) { 1095 warn_no_listener(detail); 1096 return -EINVAL; 1097 } 1098 1099 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 1100 if (!buf) 1101 return -EAGAIN; 1102 1103 crq = kmalloc(sizeof (*crq), GFP_KERNEL); 1104 if (!crq) { 1105 kfree(buf); 1106 return -EAGAIN; 1107 } 1108 1109 bp = buf; len = PAGE_SIZE; 1110 1111 cache_request(detail, h, &bp, &len); 1112 1113 if (len < 0) { 1114 kfree(buf); 1115 kfree(crq); 1116 return -EAGAIN; 1117 } 1118 crq->q.reader = 0; 1119 crq->item = cache_get(h); 1120 crq->buf = buf; 1121 crq->len = PAGE_SIZE - len; 1122 crq->readers = 0; 1123 spin_lock(&queue_lock); 1124 list_add_tail(&crq->q.list, &detail->queue); 1125 spin_unlock(&queue_lock); 1126 wake_up(&queue_wait); 1127 return 0; 1128} 1129EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); 1130 1131/* 1132 * parse a message from user-space and pass it 1133 * to an appropriate cache 1134 * Messages are, like requests, separated into fields by 1135 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal 1136 * 1137 * Message is 1138 * reply cachename expiry key ... content.... 1139 * 1140 * key and content are both parsed by cache 1141 */ 1142 1143#define isodigit(c) (isdigit(c) && c <= '7') 1144int qword_get(char **bpp, char *dest, int bufsize) 1145{ 1146 /* return bytes copied, or -1 on error */ 1147 char *bp = *bpp; 1148 int len = 0; 1149 1150 while (*bp == ' ') bp++; 1151 1152 if (bp[0] == '\\' && bp[1] == 'x') { 1153 /* HEX STRING */ 1154 bp += 2; 1155 while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { 1156 int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; 1157 bp++; 1158 byte <<= 4; 1159 byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; 1160 *dest++ = byte; 1161 bp++; 1162 len++; 1163 } 1164 } else { 1165 /* text with \nnn octal quoting */ 1166 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { 1167 if (*bp == '\\' && 1168 isodigit(bp[1]) && (bp[1] <= '3') && 1169 isodigit(bp[2]) && 1170 isodigit(bp[3])) { 1171 int byte = (*++bp -'0'); 1172 bp++; 1173 byte = (byte << 3) | (*bp++ - '0'); 1174 byte = (byte << 3) | (*bp++ - '0'); 1175 *dest++ = byte; 1176 len++; 1177 } else { 1178 *dest++ = *bp++; 1179 len++; 1180 } 1181 } 1182 } 1183 1184 if (*bp != ' ' && *bp != '\n' && *bp != '\0') 1185 return -1; 1186 while (*bp == ' ') bp++; 1187 *bpp = bp; 1188 *dest = '\0'; 1189 return len; 1190} 1191EXPORT_SYMBOL_GPL(qword_get); 1192 1193 1194/* 1195 * support /proc/sunrpc/cache/$CACHENAME/content 1196 * as a seqfile. 1197 * We call ->cache_show passing NULL for the item to 1198 * get a header, then pass each real item in the cache 1199 */ 1200 1201struct handle { 1202 struct cache_detail *cd; 1203}; 1204 1205static void *c_start(struct seq_file *m, loff_t *pos) 1206 __acquires(cd->hash_lock) 1207{ 1208 loff_t n = *pos; 1209 unsigned hash, entry; 1210 struct cache_head *ch; 1211 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1212 1213 1214 read_lock(&cd->hash_lock); 1215 if (!n--) 1216 return SEQ_START_TOKEN; 1217 hash = n >> 32; 1218 entry = n & ((1LL<<32) - 1); 1219 1220 for (ch=cd->hash_table[hash]; ch; ch=ch->next) 1221 if (!entry--) 1222 return ch; 1223 n &= ~((1LL<<32) - 1); 1224 do { 1225 hash++; 1226 n += 1LL<<32; 1227 } while(hash < cd->hash_size && 1228 cd->hash_table[hash]==NULL); 1229 if (hash >= cd->hash_size) 1230 return NULL; 1231 *pos = n+1; 1232 return cd->hash_table[hash]; 1233} 1234 1235static void *c_next(struct seq_file *m, void *p, loff_t *pos) 1236{ 1237 struct cache_head *ch = p; 1238 int hash = (*pos >> 32); 1239 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1240 1241 if (p == SEQ_START_TOKEN) 1242 hash = 0; 1243 else if (ch->next == NULL) { 1244 hash++; 1245 *pos += 1LL<<32; 1246 } else { 1247 ++*pos; 1248 return ch->next; 1249 } 1250 *pos &= ~((1LL<<32) - 1); 1251 while (hash < cd->hash_size && 1252 cd->hash_table[hash] == NULL) { 1253 hash++; 1254 *pos += 1LL<<32; 1255 } 1256 if (hash >= cd->hash_size) 1257 return NULL; 1258 ++*pos; 1259 return cd->hash_table[hash]; 1260} 1261 1262static void c_stop(struct seq_file *m, void *p) 1263 __releases(cd->hash_lock) 1264{ 1265 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1266 read_unlock(&cd->hash_lock); 1267} 1268 1269static int c_show(struct seq_file *m, void *p) 1270{ 1271 struct cache_head *cp = p; 1272 struct cache_detail *cd = ((struct handle*)m->private)->cd; 1273 1274 if (p == SEQ_START_TOKEN) 1275 return cd->cache_show(m, cd, NULL); 1276 1277 ifdebug(CACHE) 1278 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", 1279 convert_to_wallclock(cp->expiry_time), 1280 atomic_read(&cp->ref.refcount), cp->flags); 1281 cache_get(cp); 1282 if (cache_check(cd, cp, NULL)) 1283 /* cache_check does a cache_put on failure */ 1284 seq_printf(m, "# "); 1285 else 1286 cache_put(cp, cd); 1287 1288 return cd->cache_show(m, cd, cp); 1289} 1290 1291static const struct seq_operations cache_content_op = { 1292 .start = c_start, 1293 .next = c_next, 1294 .stop = c_stop, 1295 .show = c_show, 1296}; 1297 1298static int content_open(struct inode *inode, struct file *file, 1299 struct cache_detail *cd) 1300{ 1301 struct handle *han; 1302 1303 if (!cd || !try_module_get(cd->owner)) 1304 return -EACCES; 1305 han = __seq_open_private(file, &cache_content_op, sizeof(*han)); 1306 if (han == NULL) { 1307 module_put(cd->owner); 1308 return -ENOMEM; 1309 } 1310 1311 han->cd = cd; 1312 return 0; 1313} 1314 1315static int content_release(struct inode *inode, struct file *file, 1316 struct cache_detail *cd) 1317{ 1318 int ret = seq_release_private(inode, file); 1319 module_put(cd->owner); 1320 return ret; 1321} 1322 1323static int open_flush(struct inode *inode, struct file *file, 1324 struct cache_detail *cd) 1325{ 1326 if (!cd || !try_module_get(cd->owner)) 1327 return -EACCES; 1328 return nonseekable_open(inode, file); 1329} 1330 1331static int release_flush(struct inode *inode, struct file *file, 1332 struct cache_detail *cd) 1333{ 1334 module_put(cd->owner); 1335 return 0; 1336} 1337 1338static ssize_t read_flush(struct file *file, char __user *buf, 1339 size_t count, loff_t *ppos, 1340 struct cache_detail *cd) 1341{ 1342 char tbuf[20]; 1343 unsigned long p = *ppos; 1344 size_t len; 1345 1346 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time)); 1347 len = strlen(tbuf); 1348 if (p >= len) 1349 return 0; 1350 len -= p; 1351 if (len > count) 1352 len = count; 1353 if (copy_to_user(buf, (void*)(tbuf+p), len)) 1354 return -EFAULT; 1355 *ppos += len; 1356 return len; 1357} 1358 1359static ssize_t write_flush(struct file *file, const char __user *buf, 1360 size_t count, loff_t *ppos, 1361 struct cache_detail *cd) 1362{ 1363 char tbuf[20]; 1364 char *bp, *ep; 1365 1366 if (*ppos || count > sizeof(tbuf)-1) 1367 return -EINVAL; 1368 if (copy_from_user(tbuf, buf, count)) 1369 return -EFAULT; 1370 tbuf[count] = 0; 1371 simple_strtoul(tbuf, &ep, 0); 1372 if (*ep && *ep != '\n') 1373 return -EINVAL; 1374 1375 bp = tbuf; 1376 cd->flush_time = get_expiry(&bp); 1377 cd->nextcheck = seconds_since_boot(); 1378 cache_flush(); 1379 1380 *ppos += count; 1381 return count; 1382} 1383 1384static ssize_t cache_read_procfs(struct file *filp, char __user *buf, 1385 size_t count, loff_t *ppos) 1386{ 1387 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1388 1389 return cache_read(filp, buf, count, ppos, cd); 1390} 1391 1392static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, 1393 size_t count, loff_t *ppos) 1394{ 1395 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1396 1397 return cache_write(filp, buf, count, ppos, cd); 1398} 1399 1400static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) 1401{ 1402 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1403 1404 return cache_poll(filp, wait, cd); 1405} 1406 1407static long cache_ioctl_procfs(struct file *filp, 1408 unsigned int cmd, unsigned long arg) 1409{ 1410 long ret; 1411 struct inode *inode = filp->f_path.dentry->d_inode; 1412 struct cache_detail *cd = PDE(inode)->data; 1413 1414 lock_kernel(); 1415 ret = cache_ioctl(inode, filp, cmd, arg, cd); 1416 unlock_kernel(); 1417 1418 return ret; 1419} 1420 1421static int cache_open_procfs(struct inode *inode, struct file *filp) 1422{ 1423 struct cache_detail *cd = PDE(inode)->data; 1424 1425 return cache_open(inode, filp, cd); 1426} 1427 1428static int cache_release_procfs(struct inode *inode, struct file *filp) 1429{ 1430 struct cache_detail *cd = PDE(inode)->data; 1431 1432 return cache_release(inode, filp, cd); 1433} 1434 1435static const struct file_operations cache_file_operations_procfs = { 1436 .owner = THIS_MODULE, 1437 .llseek = no_llseek, 1438 .read = cache_read_procfs, 1439 .write = cache_write_procfs, 1440 .poll = cache_poll_procfs, 1441 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ 1442 .open = cache_open_procfs, 1443 .release = cache_release_procfs, 1444}; 1445 1446static int content_open_procfs(struct inode *inode, struct file *filp) 1447{ 1448 struct cache_detail *cd = PDE(inode)->data; 1449 1450 return content_open(inode, filp, cd); 1451} 1452 1453static int content_release_procfs(struct inode *inode, struct file *filp) 1454{ 1455 struct cache_detail *cd = PDE(inode)->data; 1456 1457 return content_release(inode, filp, cd); 1458} 1459 1460static const struct file_operations content_file_operations_procfs = { 1461 .open = content_open_procfs, 1462 .read = seq_read, 1463 .llseek = seq_lseek, 1464 .release = content_release_procfs, 1465}; 1466 1467static int open_flush_procfs(struct inode *inode, struct file *filp) 1468{ 1469 struct cache_detail *cd = PDE(inode)->data; 1470 1471 return open_flush(inode, filp, cd); 1472} 1473 1474static int release_flush_procfs(struct inode *inode, struct file *filp) 1475{ 1476 struct cache_detail *cd = PDE(inode)->data; 1477 1478 return release_flush(inode, filp, cd); 1479} 1480 1481static ssize_t read_flush_procfs(struct file *filp, char __user *buf, 1482 size_t count, loff_t *ppos) 1483{ 1484 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1485 1486 return read_flush(filp, buf, count, ppos, cd); 1487} 1488 1489static ssize_t write_flush_procfs(struct file *filp, 1490 const char __user *buf, 1491 size_t count, loff_t *ppos) 1492{ 1493 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; 1494 1495 return write_flush(filp, buf, count, ppos, cd); 1496} 1497 1498static const struct file_operations cache_flush_operations_procfs = { 1499 .open = open_flush_procfs, 1500 .read = read_flush_procfs, 1501 .write = write_flush_procfs, 1502 .release = release_flush_procfs, 1503}; 1504 1505static void remove_cache_proc_entries(struct cache_detail *cd) 1506{ 1507 if (cd->u.procfs.proc_ent == NULL) 1508 return; 1509 if (cd->u.procfs.flush_ent) 1510 remove_proc_entry("flush", cd->u.procfs.proc_ent); 1511 if (cd->u.procfs.channel_ent) 1512 remove_proc_entry("channel", cd->u.procfs.proc_ent); 1513 if (cd->u.procfs.content_ent) 1514 remove_proc_entry("content", cd->u.procfs.proc_ent); 1515 cd->u.procfs.proc_ent = NULL; 1516 remove_proc_entry(cd->name, proc_net_rpc); 1517} 1518 1519#ifdef CONFIG_PROC_FS 1520static int create_cache_proc_entries(struct cache_detail *cd) 1521{ 1522 struct proc_dir_entry *p; 1523 1524 cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc); 1525 if (cd->u.procfs.proc_ent == NULL) 1526 goto out_nomem; 1527 cd->u.procfs.channel_ent = NULL; 1528 cd->u.procfs.content_ent = NULL; 1529 1530 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, 1531 cd->u.procfs.proc_ent, 1532 &cache_flush_operations_procfs, cd); 1533 cd->u.procfs.flush_ent = p; 1534 if (p == NULL) 1535 goto out_nomem; 1536 1537 if (cd->cache_upcall || cd->cache_parse) { 1538 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, 1539 cd->u.procfs.proc_ent, 1540 &cache_file_operations_procfs, cd); 1541 cd->u.procfs.channel_ent = p; 1542 if (p == NULL) 1543 goto out_nomem; 1544 } 1545 if (cd->cache_show) { 1546 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, 1547 cd->u.procfs.proc_ent, 1548 &content_file_operations_procfs, cd); 1549 cd->u.procfs.content_ent = p; 1550 if (p == NULL) 1551 goto out_nomem; 1552 } 1553 return 0; 1554out_nomem: 1555 remove_cache_proc_entries(cd); 1556 return -ENOMEM; 1557} 1558#else /* CONFIG_PROC_FS */ 1559static int create_cache_proc_entries(struct cache_detail *cd) 1560{ 1561 return 0; 1562} 1563#endif 1564 1565void __init cache_initialize(void) 1566{ 1567 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean); 1568} 1569 1570int cache_register(struct cache_detail *cd) 1571{ 1572 int ret; 1573 1574 sunrpc_init_cache_detail(cd); 1575 ret = create_cache_proc_entries(cd); 1576 if (ret) 1577 sunrpc_destroy_cache_detail(cd); 1578 return ret; 1579} 1580EXPORT_SYMBOL_GPL(cache_register); 1581 1582void cache_unregister(struct cache_detail *cd) 1583{ 1584 remove_cache_proc_entries(cd); 1585 sunrpc_destroy_cache_detail(cd); 1586} 1587EXPORT_SYMBOL_GPL(cache_unregister); 1588 1589static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, 1590 size_t count, loff_t *ppos) 1591{ 1592 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1593 1594 return cache_read(filp, buf, count, ppos, cd); 1595} 1596 1597static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, 1598 size_t count, loff_t *ppos) 1599{ 1600 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1601 1602 return cache_write(filp, buf, count, ppos, cd); 1603} 1604 1605static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) 1606{ 1607 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1608 1609 return cache_poll(filp, wait, cd); 1610} 1611 1612static long cache_ioctl_pipefs(struct file *filp, 1613 unsigned int cmd, unsigned long arg) 1614{ 1615 struct inode *inode = filp->f_dentry->d_inode; 1616 struct cache_detail *cd = RPC_I(inode)->private; 1617 long ret; 1618 1619 lock_kernel(); 1620 ret = cache_ioctl(inode, filp, cmd, arg, cd); 1621 unlock_kernel(); 1622 1623 return ret; 1624} 1625 1626static int cache_open_pipefs(struct inode *inode, struct file *filp) 1627{ 1628 struct cache_detail *cd = RPC_I(inode)->private; 1629 1630 return cache_open(inode, filp, cd); 1631} 1632 1633static int cache_release_pipefs(struct inode *inode, struct file *filp) 1634{ 1635 struct cache_detail *cd = RPC_I(inode)->private; 1636 1637 return cache_release(inode, filp, cd); 1638} 1639 1640const struct file_operations cache_file_operations_pipefs = { 1641 .owner = THIS_MODULE, 1642 .llseek = no_llseek, 1643 .read = cache_read_pipefs, 1644 .write = cache_write_pipefs, 1645 .poll = cache_poll_pipefs, 1646 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ 1647 .open = cache_open_pipefs, 1648 .release = cache_release_pipefs, 1649}; 1650 1651static int content_open_pipefs(struct inode *inode, struct file *filp) 1652{ 1653 struct cache_detail *cd = RPC_I(inode)->private; 1654 1655 return content_open(inode, filp, cd); 1656} 1657 1658static int content_release_pipefs(struct inode *inode, struct file *filp) 1659{ 1660 struct cache_detail *cd = RPC_I(inode)->private; 1661 1662 return content_release(inode, filp, cd); 1663} 1664 1665const struct file_operations content_file_operations_pipefs = { 1666 .open = content_open_pipefs, 1667 .read = seq_read, 1668 .llseek = seq_lseek, 1669 .release = content_release_pipefs, 1670}; 1671 1672static int open_flush_pipefs(struct inode *inode, struct file *filp) 1673{ 1674 struct cache_detail *cd = RPC_I(inode)->private; 1675 1676 return open_flush(inode, filp, cd); 1677} 1678 1679static int release_flush_pipefs(struct inode *inode, struct file *filp) 1680{ 1681 struct cache_detail *cd = RPC_I(inode)->private; 1682 1683 return release_flush(inode, filp, cd); 1684} 1685 1686static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, 1687 size_t count, loff_t *ppos) 1688{ 1689 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1690 1691 return read_flush(filp, buf, count, ppos, cd); 1692} 1693 1694static ssize_t write_flush_pipefs(struct file *filp, 1695 const char __user *buf, 1696 size_t count, loff_t *ppos) 1697{ 1698 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; 1699 1700 return write_flush(filp, buf, count, ppos, cd); 1701} 1702 1703const struct file_operations cache_flush_operations_pipefs = { 1704 .open = open_flush_pipefs, 1705 .read = read_flush_pipefs, 1706 .write = write_flush_pipefs, 1707 .release = release_flush_pipefs, 1708}; 1709 1710int sunrpc_cache_register_pipefs(struct dentry *parent, 1711 const char *name, mode_t umode, 1712 struct cache_detail *cd) 1713{ 1714 struct qstr q; 1715 struct dentry *dir; 1716 int ret = 0; 1717 1718 sunrpc_init_cache_detail(cd); 1719 q.name = name; 1720 q.len = strlen(name); 1721 q.hash = full_name_hash(q.name, q.len); 1722 dir = rpc_create_cache_dir(parent, &q, umode, cd); 1723 if (!IS_ERR(dir)) 1724 cd->u.pipefs.dir = dir; 1725 else { 1726 sunrpc_destroy_cache_detail(cd); 1727 ret = PTR_ERR(dir); 1728 } 1729 return ret; 1730} 1731EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); 1732 1733void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) 1734{ 1735 rpc_remove_cache_dir(cd->u.pipefs.dir); 1736 cd->u.pipefs.dir = NULL; 1737 sunrpc_destroy_cache_detail(cd); 1738} 1739EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); 1740 1741