Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / sunrpc / cache.c
blob8a7e1c774f9c5933e6de54e992ded2c0540066fc
1 /*
2 * net/sunrpc/cache.c
4 * Generic code for various authentication-related caches
5 * used by sunrpc clients and servers.
7 * Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au>
9 * Released under terms in GPL version 2. See COPYING.
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 <linux/string_helpers.h>
24 #include <linux/uaccess.h>
25 #include <linux/poll.h>
26 #include <linux/seq_file.h>
27 #include <linux/proc_fs.h>
28 #include <linux/net.h>
29 #include <linux/workqueue.h>
30 #include <linux/mutex.h>
31 #include <linux/pagemap.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 #include "netns.h"
39 #define RPCDBG_FACILITY RPCDBG_CACHE
41 static bool cache_defer_req(struct cache_req *req, struct cache_head *item);
42 static void cache_revisit_request(struct cache_head *item);
44 static void cache_init(struct cache_head *h, struct cache_detail *detail)
46 time_t now = seconds_since_boot();
47 INIT_HLIST_NODE(&h->cache_list);
48 h->flags = 0;
49 kref_init(&h->ref);
50 h->expiry_time = now + CACHE_NEW_EXPIRY;
51 if (now <= detail->flush_time)
52 /* ensure it isn't already expired */
53 now = detail->flush_time + 1;
54 h->last_refresh = now;
57 struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
58 struct cache_head *key, int hash)
60 struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL;
61 struct hlist_head *head;
63 head = &detail->hash_table[hash];
65 read_lock(&detail->hash_lock);
67 hlist_for_each_entry(tmp, head, cache_list) {
68 if (detail->match(tmp, key)) {
69 if (cache_is_expired(detail, tmp))
70 /* This entry is expired, we will discard it. */
71 break;
72 cache_get(tmp);
73 read_unlock(&detail->hash_lock);
74 return tmp;
77 read_unlock(&detail->hash_lock);
78 /* Didn't find anything, insert an empty entry */
80 new = detail->alloc();
81 if (!new)
82 return NULL;
83 /* must fully initialise 'new', else
84 * we might get lose if we need to
85 * cache_put it soon.
87 cache_init(new, detail);
88 detail->init(new, key);
90 write_lock(&detail->hash_lock);
92 /* check if entry appeared while we slept */
93 hlist_for_each_entry(tmp, head, cache_list) {
94 if (detail->match(tmp, key)) {
95 if (cache_is_expired(detail, tmp)) {
96 hlist_del_init(&tmp->cache_list);
97 detail->entries --;
98 freeme = tmp;
99 break;
101 cache_get(tmp);
102 write_unlock(&detail->hash_lock);
103 cache_put(new, detail);
104 return tmp;
108 hlist_add_head(&new->cache_list, head);
109 detail->entries++;
110 cache_get(new);
111 write_unlock(&detail->hash_lock);
113 if (freeme)
114 cache_put(freeme, detail);
115 return new;
117 EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
120 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
122 static void cache_fresh_locked(struct cache_head *head, time_t expiry,
123 struct cache_detail *detail)
125 time_t now = seconds_since_boot();
126 if (now <= detail->flush_time)
127 /* ensure it isn't immediately treated as expired */
128 now = detail->flush_time + 1;
129 head->expiry_time = expiry;
130 head->last_refresh = now;
131 smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
132 set_bit(CACHE_VALID, &head->flags);
135 static void cache_fresh_unlocked(struct cache_head *head,
136 struct cache_detail *detail)
138 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
139 cache_revisit_request(head);
140 cache_dequeue(detail, head);
144 struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
145 struct cache_head *new, struct cache_head *old, int hash)
147 /* The 'old' entry is to be replaced by 'new'.
148 * If 'old' is not VALID, we update it directly,
149 * otherwise we need to replace it
151 struct cache_head *tmp;
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, detail);
161 write_unlock(&detail->hash_lock);
162 cache_fresh_unlocked(old, detail);
163 return old;
165 write_unlock(&detail->hash_lock);
167 /* We need to insert a new entry */
168 tmp = detail->alloc();
169 if (!tmp) {
170 cache_put(old, detail);
171 return NULL;
173 cache_init(tmp, detail);
174 detail->init(tmp, old);
176 write_lock(&detail->hash_lock);
177 if (test_bit(CACHE_NEGATIVE, &new->flags))
178 set_bit(CACHE_NEGATIVE, &tmp->flags);
179 else
180 detail->update(tmp, new);
181 hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
182 detail->entries++;
183 cache_get(tmp);
184 cache_fresh_locked(tmp, new->expiry_time, detail);
185 cache_fresh_locked(old, 0, detail);
186 write_unlock(&detail->hash_lock);
187 cache_fresh_unlocked(tmp, detail);
188 cache_fresh_unlocked(old, detail);
189 cache_put(old, detail);
190 return tmp;
192 EXPORT_SYMBOL_GPL(sunrpc_cache_update);
194 static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
196 if (cd->cache_upcall)
197 return cd->cache_upcall(cd, h);
198 return sunrpc_cache_pipe_upcall(cd, h);
201 static inline int cache_is_valid(struct cache_head *h)
203 if (!test_bit(CACHE_VALID, &h->flags))
204 return -EAGAIN;
205 else {
206 /* entry is valid */
207 if (test_bit(CACHE_NEGATIVE, &h->flags))
208 return -ENOENT;
209 else {
211 * In combination with write barrier in
212 * sunrpc_cache_update, ensures that anyone
213 * using the cache entry after this sees the
214 * updated contents:
216 smp_rmb();
217 return 0;
222 static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
224 int rv;
226 write_lock(&detail->hash_lock);
227 rv = cache_is_valid(h);
228 if (rv == -EAGAIN) {
229 set_bit(CACHE_NEGATIVE, &h->flags);
230 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
231 detail);
232 rv = -ENOENT;
234 write_unlock(&detail->hash_lock);
235 cache_fresh_unlocked(h, detail);
236 return rv;
240 * This is the generic cache management routine for all
241 * the authentication caches.
242 * It checks the currency of a cache item and will (later)
243 * initiate an upcall to fill it if needed.
246 * Returns 0 if the cache_head can be used, or cache_puts it and returns
247 * -EAGAIN if upcall is pending and request has been queued
248 * -ETIMEDOUT if upcall failed or request could not be queue or
249 * upcall completed but item is still invalid (implying that
250 * the cache item has been replaced with a newer one).
251 * -ENOENT if cache entry was negative
253 int cache_check(struct cache_detail *detail,
254 struct cache_head *h, struct cache_req *rqstp)
256 int rv;
257 long refresh_age, age;
259 /* First decide return status as best we can */
260 rv = cache_is_valid(h);
262 /* now see if we want to start an upcall */
263 refresh_age = (h->expiry_time - h->last_refresh);
264 age = seconds_since_boot() - h->last_refresh;
266 if (rqstp == NULL) {
267 if (rv == -EAGAIN)
268 rv = -ENOENT;
269 } else if (rv == -EAGAIN ||
270 (h->expiry_time != 0 && age > refresh_age/2)) {
271 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
272 refresh_age, age);
273 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
274 switch (cache_make_upcall(detail, h)) {
275 case -EINVAL:
276 rv = try_to_negate_entry(detail, h);
277 break;
278 case -EAGAIN:
279 cache_fresh_unlocked(h, detail);
280 break;
285 if (rv == -EAGAIN) {
286 if (!cache_defer_req(rqstp, h)) {
288 * Request was not deferred; handle it as best
289 * we can ourselves:
291 rv = cache_is_valid(h);
292 if (rv == -EAGAIN)
293 rv = -ETIMEDOUT;
296 if (rv)
297 cache_put(h, detail);
298 return rv;
300 EXPORT_SYMBOL_GPL(cache_check);
303 * caches need to be periodically cleaned.
304 * For this we maintain a list of cache_detail and
305 * a current pointer into that list and into the table
306 * for that entry.
308 * Each time cache_clean is called it finds the next non-empty entry
309 * in the current table and walks the list in that entry
310 * looking for entries that can be removed.
312 * An entry gets removed if:
313 * - The expiry is before current time
314 * - The last_refresh time is before the flush_time for that cache
316 * later we might drop old entries with non-NEVER expiry if that table
317 * is getting 'full' for some definition of 'full'
319 * The question of "how often to scan a table" is an interesting one
320 * and is answered in part by the use of the "nextcheck" field in the
321 * cache_detail.
322 * When a scan of a table begins, the nextcheck field is set to a time
323 * that is well into the future.
324 * While scanning, if an expiry time is found that is earlier than the
325 * current nextcheck time, nextcheck is set to that expiry time.
326 * If the flush_time is ever set to a time earlier than the nextcheck
327 * time, the nextcheck time is then set to that flush_time.
329 * A table is then only scanned if the current time is at least
330 * the nextcheck time.
334 static LIST_HEAD(cache_list);
335 static DEFINE_SPINLOCK(cache_list_lock);
336 static struct cache_detail *current_detail;
337 static int current_index;
339 static void do_cache_clean(struct work_struct *work);
340 static struct delayed_work cache_cleaner;
342 void sunrpc_init_cache_detail(struct cache_detail *cd)
344 rwlock_init(&cd->hash_lock);
345 INIT_LIST_HEAD(&cd->queue);
346 spin_lock(&cache_list_lock);
347 cd->nextcheck = 0;
348 cd->entries = 0;
349 atomic_set(&cd->readers, 0);
350 cd->last_close = 0;
351 cd->last_warn = -1;
352 list_add(&cd->others, &cache_list);
353 spin_unlock(&cache_list_lock);
355 /* start the cleaning process */
356 queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0);
358 EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
360 void sunrpc_destroy_cache_detail(struct cache_detail *cd)
362 cache_purge(cd);
363 spin_lock(&cache_list_lock);
364 write_lock(&cd->hash_lock);
365 if (current_detail == cd)
366 current_detail = NULL;
367 list_del_init(&cd->others);
368 write_unlock(&cd->hash_lock);
369 spin_unlock(&cache_list_lock);
370 if (list_empty(&cache_list)) {
371 /* module must be being unloaded so its safe to kill the worker */
372 cancel_delayed_work_sync(&cache_cleaner);
375 EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
377 /* clean cache tries to find something to clean
378 * and cleans it.
379 * It returns 1 if it cleaned something,
380 * 0 if it didn't find anything this time
381 * -1 if it fell off the end of the list.
383 static int cache_clean(void)
385 int rv = 0;
386 struct list_head *next;
388 spin_lock(&cache_list_lock);
390 /* find a suitable table if we don't already have one */
391 while (current_detail == NULL ||
392 current_index >= current_detail->hash_size) {
393 if (current_detail)
394 next = current_detail->others.next;
395 else
396 next = cache_list.next;
397 if (next == &cache_list) {
398 current_detail = NULL;
399 spin_unlock(&cache_list_lock);
400 return -1;
402 current_detail = list_entry(next, struct cache_detail, others);
403 if (current_detail->nextcheck > seconds_since_boot())
404 current_index = current_detail->hash_size;
405 else {
406 current_index = 0;
407 current_detail->nextcheck = seconds_since_boot()+30*60;
411 /* find a non-empty bucket in the table */
412 while (current_detail &&
413 current_index < current_detail->hash_size &&
414 hlist_empty(&current_detail->hash_table[current_index]))
415 current_index++;
417 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
419 if (current_detail && current_index < current_detail->hash_size) {
420 struct cache_head *ch = NULL;
421 struct cache_detail *d;
422 struct hlist_head *head;
423 struct hlist_node *tmp;
425 write_lock(&current_detail->hash_lock);
427 /* Ok, now to clean this strand */
429 head = &current_detail->hash_table[current_index];
430 hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
431 if (current_detail->nextcheck > ch->expiry_time)
432 current_detail->nextcheck = ch->expiry_time+1;
433 if (!cache_is_expired(current_detail, ch))
434 continue;
436 hlist_del_init(&ch->cache_list);
437 current_detail->entries--;
438 rv = 1;
439 break;
442 write_unlock(&current_detail->hash_lock);
443 d = current_detail;
444 if (!ch)
445 current_index ++;
446 spin_unlock(&cache_list_lock);
447 if (ch) {
448 set_bit(CACHE_CLEANED, &ch->flags);
449 cache_fresh_unlocked(ch, d);
450 cache_put(ch, d);
452 } else
453 spin_unlock(&cache_list_lock);
455 return rv;
459 * We want to regularly clean the cache, so we need to schedule some work ...
461 static void do_cache_clean(struct work_struct *work)
463 int delay = 5;
464 if (cache_clean() == -1)
465 delay = round_jiffies_relative(30*HZ);
467 if (list_empty(&cache_list))
468 delay = 0;
470 if (delay)
471 queue_delayed_work(system_power_efficient_wq,
472 &cache_cleaner, delay);
477 * Clean all caches promptly. This just calls cache_clean
478 * repeatedly until we are sure that every cache has had a chance to
479 * be fully cleaned
481 void cache_flush(void)
483 while (cache_clean() != -1)
484 cond_resched();
485 while (cache_clean() != -1)
486 cond_resched();
488 EXPORT_SYMBOL_GPL(cache_flush);
490 void cache_purge(struct cache_detail *detail)
492 struct cache_head *ch = NULL;
493 struct hlist_head *head = NULL;
494 struct hlist_node *tmp = NULL;
495 int i = 0;
497 write_lock(&detail->hash_lock);
498 if (!detail->entries) {
499 write_unlock(&detail->hash_lock);
500 return;
503 dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name);
504 for (i = 0; i < detail->hash_size; i++) {
505 head = &detail->hash_table[i];
506 hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
507 hlist_del_init(&ch->cache_list);
508 detail->entries--;
510 set_bit(CACHE_CLEANED, &ch->flags);
511 write_unlock(&detail->hash_lock);
512 cache_fresh_unlocked(ch, detail);
513 cache_put(ch, detail);
514 write_lock(&detail->hash_lock);
517 write_unlock(&detail->hash_lock);
519 EXPORT_SYMBOL_GPL(cache_purge);
523 * Deferral and Revisiting of Requests.
525 * If a cache lookup finds a pending entry, we
526 * need to defer the request and revisit it later.
527 * All deferred requests are stored in a hash table,
528 * indexed by "struct cache_head *".
529 * As it may be wasteful to store a whole request
530 * structure, we allow the request to provide a
531 * deferred form, which must contain a
532 * 'struct cache_deferred_req'
533 * This cache_deferred_req contains a method to allow
534 * it to be revisited when cache info is available
537 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
538 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
540 #define DFR_MAX 300 /* ??? */
542 static DEFINE_SPINLOCK(cache_defer_lock);
543 static LIST_HEAD(cache_defer_list);
544 static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
545 static int cache_defer_cnt;
547 static void __unhash_deferred_req(struct cache_deferred_req *dreq)
549 hlist_del_init(&dreq->hash);
550 if (!list_empty(&dreq->recent)) {
551 list_del_init(&dreq->recent);
552 cache_defer_cnt--;
556 static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
558 int hash = DFR_HASH(item);
560 INIT_LIST_HEAD(&dreq->recent);
561 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
564 static void setup_deferral(struct cache_deferred_req *dreq,
565 struct cache_head *item,
566 int count_me)
569 dreq->item = item;
571 spin_lock(&cache_defer_lock);
573 __hash_deferred_req(dreq, item);
575 if (count_me) {
576 cache_defer_cnt++;
577 list_add(&dreq->recent, &cache_defer_list);
580 spin_unlock(&cache_defer_lock);
584 struct thread_deferred_req {
585 struct cache_deferred_req handle;
586 struct completion completion;
589 static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
591 struct thread_deferred_req *dr =
592 container_of(dreq, struct thread_deferred_req, handle);
593 complete(&dr->completion);
596 static void cache_wait_req(struct cache_req *req, struct cache_head *item)
598 struct thread_deferred_req sleeper;
599 struct cache_deferred_req *dreq = &sleeper.handle;
601 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
602 dreq->revisit = cache_restart_thread;
604 setup_deferral(dreq, item, 0);
606 if (!test_bit(CACHE_PENDING, &item->flags) ||
607 wait_for_completion_interruptible_timeout(
608 &sleeper.completion, req->thread_wait) <= 0) {
609 /* The completion wasn't completed, so we need
610 * to clean up
612 spin_lock(&cache_defer_lock);
613 if (!hlist_unhashed(&sleeper.handle.hash)) {
614 __unhash_deferred_req(&sleeper.handle);
615 spin_unlock(&cache_defer_lock);
616 } else {
617 /* cache_revisit_request already removed
618 * this from the hash table, but hasn't
619 * called ->revisit yet. It will very soon
620 * and we need to wait for it.
622 spin_unlock(&cache_defer_lock);
623 wait_for_completion(&sleeper.completion);
628 static void cache_limit_defers(void)
630 /* Make sure we haven't exceed the limit of allowed deferred
631 * requests.
633 struct cache_deferred_req *discard = NULL;
635 if (cache_defer_cnt <= DFR_MAX)
636 return;
638 spin_lock(&cache_defer_lock);
640 /* Consider removing either the first or the last */
641 if (cache_defer_cnt > DFR_MAX) {
642 if (prandom_u32() & 1)
643 discard = list_entry(cache_defer_list.next,
644 struct cache_deferred_req, recent);
645 else
646 discard = list_entry(cache_defer_list.prev,
647 struct cache_deferred_req, recent);
648 __unhash_deferred_req(discard);
650 spin_unlock(&cache_defer_lock);
651 if (discard)
652 discard->revisit(discard, 1);
655 /* Return true if and only if a deferred request is queued. */
656 static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
658 struct cache_deferred_req *dreq;
660 if (req->thread_wait) {
661 cache_wait_req(req, item);
662 if (!test_bit(CACHE_PENDING, &item->flags))
663 return false;
665 dreq = req->defer(req);
666 if (dreq == NULL)
667 return false;
668 setup_deferral(dreq, item, 1);
669 if (!test_bit(CACHE_PENDING, &item->flags))
670 /* Bit could have been cleared before we managed to
671 * set up the deferral, so need to revisit just in case
673 cache_revisit_request(item);
675 cache_limit_defers();
676 return true;
679 static void cache_revisit_request(struct cache_head *item)
681 struct cache_deferred_req *dreq;
682 struct list_head pending;
683 struct hlist_node *tmp;
684 int hash = DFR_HASH(item);
686 INIT_LIST_HEAD(&pending);
687 spin_lock(&cache_defer_lock);
689 hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash)
690 if (dreq->item == item) {
691 __unhash_deferred_req(dreq);
692 list_add(&dreq->recent, &pending);
695 spin_unlock(&cache_defer_lock);
697 while (!list_empty(&pending)) {
698 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
699 list_del_init(&dreq->recent);
700 dreq->revisit(dreq, 0);
704 void cache_clean_deferred(void *owner)
706 struct cache_deferred_req *dreq, *tmp;
707 struct list_head pending;
710 INIT_LIST_HEAD(&pending);
711 spin_lock(&cache_defer_lock);
713 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
714 if (dreq->owner == owner) {
715 __unhash_deferred_req(dreq);
716 list_add(&dreq->recent, &pending);
719 spin_unlock(&cache_defer_lock);
721 while (!list_empty(&pending)) {
722 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
723 list_del_init(&dreq->recent);
724 dreq->revisit(dreq, 1);
729 * communicate with user-space
731 * We have a magic /proc file - /proc/net/rpc/<cachename>/channel.
732 * On read, you get a full request, or block.
733 * On write, an update request is processed.
734 * Poll works if anything to read, and always allows write.
736 * Implemented by linked list of requests. Each open file has
737 * a ->private that also exists in this list. New requests are added
738 * to the end and may wakeup and preceding readers.
739 * New readers are added to the head. If, on read, an item is found with
740 * CACHE_UPCALLING clear, we free it from the list.
744 static DEFINE_SPINLOCK(queue_lock);
745 static DEFINE_MUTEX(queue_io_mutex);
747 struct cache_queue {
748 struct list_head list;
749 int reader; /* if 0, then request */
751 struct cache_request {
752 struct cache_queue q;
753 struct cache_head *item;
754 char * buf;
755 int len;
756 int readers;
758 struct cache_reader {
759 struct cache_queue q;
760 int offset; /* if non-0, we have a refcnt on next request */
763 static int cache_request(struct cache_detail *detail,
764 struct cache_request *crq)
766 char *bp = crq->buf;
767 int len = PAGE_SIZE;
769 detail->cache_request(detail, crq->item, &bp, &len);
770 if (len < 0)
771 return -EAGAIN;
772 return PAGE_SIZE - len;
775 static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
776 loff_t *ppos, struct cache_detail *cd)
778 struct cache_reader *rp = filp->private_data;
779 struct cache_request *rq;
780 struct inode *inode = file_inode(filp);
781 int err;
783 if (count == 0)
784 return 0;
786 inode_lock(inode); /* protect against multiple concurrent
787 * readers on this file */
788 again:
789 spin_lock(&queue_lock);
790 /* need to find next request */
791 while (rp->q.list.next != &cd->queue &&
792 list_entry(rp->q.list.next, struct cache_queue, list)
793 ->reader) {
794 struct list_head *next = rp->q.list.next;
795 list_move(&rp->q.list, next);
797 if (rp->q.list.next == &cd->queue) {
798 spin_unlock(&queue_lock);
799 inode_unlock(inode);
800 WARN_ON_ONCE(rp->offset);
801 return 0;
803 rq = container_of(rp->q.list.next, struct cache_request, q.list);
804 WARN_ON_ONCE(rq->q.reader);
805 if (rp->offset == 0)
806 rq->readers++;
807 spin_unlock(&queue_lock);
809 if (rq->len == 0) {
810 err = cache_request(cd, rq);
811 if (err < 0)
812 goto out;
813 rq->len = err;
816 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
817 err = -EAGAIN;
818 spin_lock(&queue_lock);
819 list_move(&rp->q.list, &rq->q.list);
820 spin_unlock(&queue_lock);
821 } else {
822 if (rp->offset + count > rq->len)
823 count = rq->len - rp->offset;
824 err = -EFAULT;
825 if (copy_to_user(buf, rq->buf + rp->offset, count))
826 goto out;
827 rp->offset += count;
828 if (rp->offset >= rq->len) {
829 rp->offset = 0;
830 spin_lock(&queue_lock);
831 list_move(&rp->q.list, &rq->q.list);
832 spin_unlock(&queue_lock);
834 err = 0;
836 out:
837 if (rp->offset == 0) {
838 /* need to release rq */
839 spin_lock(&queue_lock);
840 rq->readers--;
841 if (rq->readers == 0 &&
842 !test_bit(CACHE_PENDING, &rq->item->flags)) {
843 list_del(&rq->q.list);
844 spin_unlock(&queue_lock);
845 cache_put(rq->item, cd);
846 kfree(rq->buf);
847 kfree(rq);
848 } else
849 spin_unlock(&queue_lock);
851 if (err == -EAGAIN)
852 goto again;
853 inode_unlock(inode);
854 return err ? err : count;
857 static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
858 size_t count, struct cache_detail *cd)
860 ssize_t ret;
862 if (count == 0)
863 return -EINVAL;
864 if (copy_from_user(kaddr, buf, count))
865 return -EFAULT;
866 kaddr[count] = '\0';
867 ret = cd->cache_parse(cd, kaddr, count);
868 if (!ret)
869 ret = count;
870 return ret;
873 static ssize_t cache_slow_downcall(const char __user *buf,
874 size_t count, struct cache_detail *cd)
876 static char write_buf[8192]; /* protected by queue_io_mutex */
877 ssize_t ret = -EINVAL;
879 if (count >= sizeof(write_buf))
880 goto out;
881 mutex_lock(&queue_io_mutex);
882 ret = cache_do_downcall(write_buf, buf, count, cd);
883 mutex_unlock(&queue_io_mutex);
884 out:
885 return ret;
888 static ssize_t cache_downcall(struct address_space *mapping,
889 const char __user *buf,
890 size_t count, struct cache_detail *cd)
892 struct page *page;
893 char *kaddr;
894 ssize_t ret = -ENOMEM;
896 if (count >= PAGE_SIZE)
897 goto out_slow;
899 page = find_or_create_page(mapping, 0, GFP_KERNEL);
900 if (!page)
901 goto out_slow;
903 kaddr = kmap(page);
904 ret = cache_do_downcall(kaddr, buf, count, cd);
905 kunmap(page);
906 unlock_page(page);
907 put_page(page);
908 return ret;
909 out_slow:
910 return cache_slow_downcall(buf, count, cd);
913 static ssize_t cache_write(struct file *filp, const char __user *buf,
914 size_t count, loff_t *ppos,
915 struct cache_detail *cd)
917 struct address_space *mapping = filp->f_mapping;
918 struct inode *inode = file_inode(filp);
919 ssize_t ret = -EINVAL;
921 if (!cd->cache_parse)
922 goto out;
924 inode_lock(inode);
925 ret = cache_downcall(mapping, buf, count, cd);
926 inode_unlock(inode);
927 out:
928 return ret;
931 static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
933 static __poll_t cache_poll(struct file *filp, poll_table *wait,
934 struct cache_detail *cd)
936 __poll_t mask;
937 struct cache_reader *rp = filp->private_data;
938 struct cache_queue *cq;
940 poll_wait(filp, &queue_wait, wait);
942 /* alway allow write */
943 mask = EPOLLOUT | EPOLLWRNORM;
945 if (!rp)
946 return mask;
948 spin_lock(&queue_lock);
950 for (cq= &rp->q; &cq->list != &cd->queue;
951 cq = list_entry(cq->list.next, struct cache_queue, list))
952 if (!cq->reader) {
953 mask |= EPOLLIN | EPOLLRDNORM;
954 break;
956 spin_unlock(&queue_lock);
957 return mask;
960 static int cache_ioctl(struct inode *ino, struct file *filp,
961 unsigned int cmd, unsigned long arg,
962 struct cache_detail *cd)
964 int len = 0;
965 struct cache_reader *rp = filp->private_data;
966 struct cache_queue *cq;
968 if (cmd != FIONREAD || !rp)
969 return -EINVAL;
971 spin_lock(&queue_lock);
973 /* only find the length remaining in current request,
974 * or the length of the next request
976 for (cq= &rp->q; &cq->list != &cd->queue;
977 cq = list_entry(cq->list.next, struct cache_queue, list))
978 if (!cq->reader) {
979 struct cache_request *cr =
980 container_of(cq, struct cache_request, q);
981 len = cr->len - rp->offset;
982 break;
984 spin_unlock(&queue_lock);
986 return put_user(len, (int __user *)arg);
989 static int cache_open(struct inode *inode, struct file *filp,
990 struct cache_detail *cd)
992 struct cache_reader *rp = NULL;
994 if (!cd || !try_module_get(cd->owner))
995 return -EACCES;
996 nonseekable_open(inode, filp);
997 if (filp->f_mode & FMODE_READ) {
998 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
999 if (!rp) {
1000 module_put(cd->owner);
1001 return -ENOMEM;
1003 rp->offset = 0;
1004 rp->q.reader = 1;
1005 atomic_inc(&cd->readers);
1006 spin_lock(&queue_lock);
1007 list_add(&rp->q.list, &cd->queue);
1008 spin_unlock(&queue_lock);
1010 filp->private_data = rp;
1011 return 0;
1014 static int cache_release(struct inode *inode, struct file *filp,
1015 struct cache_detail *cd)
1017 struct cache_reader *rp = filp->private_data;
1019 if (rp) {
1020 spin_lock(&queue_lock);
1021 if (rp->offset) {
1022 struct cache_queue *cq;
1023 for (cq= &rp->q; &cq->list != &cd->queue;
1024 cq = list_entry(cq->list.next, struct cache_queue, list))
1025 if (!cq->reader) {
1026 container_of(cq, struct cache_request, q)
1027 ->readers--;
1028 break;
1030 rp->offset = 0;
1032 list_del(&rp->q.list);
1033 spin_unlock(&queue_lock);
1035 filp->private_data = NULL;
1036 kfree(rp);
1038 cd->last_close = seconds_since_boot();
1039 atomic_dec(&cd->readers);
1041 module_put(cd->owner);
1042 return 0;
1047 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
1049 struct cache_queue *cq, *tmp;
1050 struct cache_request *cr;
1051 struct list_head dequeued;
1053 INIT_LIST_HEAD(&dequeued);
1054 spin_lock(&queue_lock);
1055 list_for_each_entry_safe(cq, tmp, &detail->queue, list)
1056 if (!cq->reader) {
1057 cr = container_of(cq, struct cache_request, q);
1058 if (cr->item != ch)
1059 continue;
1060 if (test_bit(CACHE_PENDING, &ch->flags))
1061 /* Lost a race and it is pending again */
1062 break;
1063 if (cr->readers != 0)
1064 continue;
1065 list_move(&cr->q.list, &dequeued);
1067 spin_unlock(&queue_lock);
1068 while (!list_empty(&dequeued)) {
1069 cr = list_entry(dequeued.next, struct cache_request, q.list);
1070 list_del(&cr->q.list);
1071 cache_put(cr->item, detail);
1072 kfree(cr->buf);
1073 kfree(cr);
1078 * Support routines for text-based upcalls.
1079 * Fields are separated by spaces.
1080 * Fields are either mangled to quote space tab newline slosh with slosh
1081 * or a hexified with a leading \x
1082 * Record is terminated with newline.
1086 void qword_add(char **bpp, int *lp, char *str)
1088 char *bp = *bpp;
1089 int len = *lp;
1090 int ret;
1092 if (len < 0) return;
1094 ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
1095 if (ret >= len) {
1096 bp += len;
1097 len = -1;
1098 } else {
1099 bp += ret;
1100 len -= ret;
1101 *bp++ = ' ';
1102 len--;
1104 *bpp = bp;
1105 *lp = len;
1107 EXPORT_SYMBOL_GPL(qword_add);
1109 void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1111 char *bp = *bpp;
1112 int len = *lp;
1114 if (len < 0) return;
1116 if (len > 2) {
1117 *bp++ = '\\';
1118 *bp++ = 'x';
1119 len -= 2;
1120 while (blen && len >= 2) {
1121 bp = hex_byte_pack(bp, *buf++);
1122 len -= 2;
1123 blen--;
1126 if (blen || len<1) len = -1;
1127 else {
1128 *bp++ = ' ';
1129 len--;
1131 *bpp = bp;
1132 *lp = len;
1134 EXPORT_SYMBOL_GPL(qword_addhex);
1136 static void warn_no_listener(struct cache_detail *detail)
1138 if (detail->last_warn != detail->last_close) {
1139 detail->last_warn = detail->last_close;
1140 if (detail->warn_no_listener)
1141 detail->warn_no_listener(detail, detail->last_close != 0);
1145 static bool cache_listeners_exist(struct cache_detail *detail)
1147 if (atomic_read(&detail->readers))
1148 return true;
1149 if (detail->last_close == 0)
1150 /* This cache was never opened */
1151 return false;
1152 if (detail->last_close < seconds_since_boot() - 30)
1154 * We allow for the possibility that someone might
1155 * restart a userspace daemon without restarting the
1156 * server; but after 30 seconds, we give up.
1158 return false;
1159 return true;
1163 * register an upcall request to user-space and queue it up for read() by the
1164 * upcall daemon.
1166 * Each request is at most one page long.
1168 int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
1171 char *buf;
1172 struct cache_request *crq;
1173 int ret = 0;
1175 if (!detail->cache_request)
1176 return -EINVAL;
1178 if (!cache_listeners_exist(detail)) {
1179 warn_no_listener(detail);
1180 return -EINVAL;
1182 if (test_bit(CACHE_CLEANED, &h->flags))
1183 /* Too late to make an upcall */
1184 return -EAGAIN;
1186 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1187 if (!buf)
1188 return -EAGAIN;
1190 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1191 if (!crq) {
1192 kfree(buf);
1193 return -EAGAIN;
1196 crq->q.reader = 0;
1197 crq->buf = buf;
1198 crq->len = 0;
1199 crq->readers = 0;
1200 spin_lock(&queue_lock);
1201 if (test_bit(CACHE_PENDING, &h->flags)) {
1202 crq->item = cache_get(h);
1203 list_add_tail(&crq->q.list, &detail->queue);
1204 } else
1205 /* Lost a race, no longer PENDING, so don't enqueue */
1206 ret = -EAGAIN;
1207 spin_unlock(&queue_lock);
1208 wake_up(&queue_wait);
1209 if (ret == -EAGAIN) {
1210 kfree(buf);
1211 kfree(crq);
1213 return ret;
1215 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
1218 * parse a message from user-space and pass it
1219 * to an appropriate cache
1220 * Messages are, like requests, separated into fields by
1221 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1223 * Message is
1224 * reply cachename expiry key ... content....
1226 * key and content are both parsed by cache
1229 int qword_get(char **bpp, char *dest, int bufsize)
1231 /* return bytes copied, or -1 on error */
1232 char *bp = *bpp;
1233 int len = 0;
1235 while (*bp == ' ') bp++;
1237 if (bp[0] == '\\' && bp[1] == 'x') {
1238 /* HEX STRING */
1239 bp += 2;
1240 while (len < bufsize - 1) {
1241 int h, l;
1243 h = hex_to_bin(bp[0]);
1244 if (h < 0)
1245 break;
1247 l = hex_to_bin(bp[1]);
1248 if (l < 0)
1249 break;
1251 *dest++ = (h << 4) | l;
1252 bp += 2;
1253 len++;
1255 } else {
1256 /* text with \nnn octal quoting */
1257 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1258 if (*bp == '\\' &&
1259 isodigit(bp[1]) && (bp[1] <= '3') &&
1260 isodigit(bp[2]) &&
1261 isodigit(bp[3])) {
1262 int byte = (*++bp -'0');
1263 bp++;
1264 byte = (byte << 3) | (*bp++ - '0');
1265 byte = (byte << 3) | (*bp++ - '0');
1266 *dest++ = byte;
1267 len++;
1268 } else {
1269 *dest++ = *bp++;
1270 len++;
1275 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1276 return -1;
1277 while (*bp == ' ') bp++;
1278 *bpp = bp;
1279 *dest = '\0';
1280 return len;
1282 EXPORT_SYMBOL_GPL(qword_get);
1286 * support /proc/net/rpc/$CACHENAME/content
1287 * as a seqfile.
1288 * We call ->cache_show passing NULL for the item to
1289 * get a header, then pass each real item in the cache
1292 void *cache_seq_start(struct seq_file *m, loff_t *pos)
1293 __acquires(cd->hash_lock)
1295 loff_t n = *pos;
1296 unsigned int hash, entry;
1297 struct cache_head *ch;
1298 struct cache_detail *cd = m->private;
1300 read_lock(&cd->hash_lock);
1301 if (!n--)
1302 return SEQ_START_TOKEN;
1303 hash = n >> 32;
1304 entry = n & ((1LL<<32) - 1);
1306 hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list)
1307 if (!entry--)
1308 return ch;
1309 n &= ~((1LL<<32) - 1);
1310 do {
1311 hash++;
1312 n += 1LL<<32;
1313 } while(hash < cd->hash_size &&
1314 hlist_empty(&cd->hash_table[hash]));
1315 if (hash >= cd->hash_size)
1316 return NULL;
1317 *pos = n+1;
1318 return hlist_entry_safe(cd->hash_table[hash].first,
1319 struct cache_head, cache_list);
1321 EXPORT_SYMBOL_GPL(cache_seq_start);
1323 void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
1325 struct cache_head *ch = p;
1326 int hash = (*pos >> 32);
1327 struct cache_detail *cd = m->private;
1329 if (p == SEQ_START_TOKEN)
1330 hash = 0;
1331 else if (ch->cache_list.next == NULL) {
1332 hash++;
1333 *pos += 1LL<<32;
1334 } else {
1335 ++*pos;
1336 return hlist_entry_safe(ch->cache_list.next,
1337 struct cache_head, cache_list);
1339 *pos &= ~((1LL<<32) - 1);
1340 while (hash < cd->hash_size &&
1341 hlist_empty(&cd->hash_table[hash])) {
1342 hash++;
1343 *pos += 1LL<<32;
1345 if (hash >= cd->hash_size)
1346 return NULL;
1347 ++*pos;
1348 return hlist_entry_safe(cd->hash_table[hash].first,
1349 struct cache_head, cache_list);
1351 EXPORT_SYMBOL_GPL(cache_seq_next);
1353 void cache_seq_stop(struct seq_file *m, void *p)
1354 __releases(cd->hash_lock)
1356 struct cache_detail *cd = m->private;
1357 read_unlock(&cd->hash_lock);
1359 EXPORT_SYMBOL_GPL(cache_seq_stop);
1361 static int c_show(struct seq_file *m, void *p)
1363 struct cache_head *cp = p;
1364 struct cache_detail *cd = m->private;
1366 if (p == SEQ_START_TOKEN)
1367 return cd->cache_show(m, cd, NULL);
1369 ifdebug(CACHE)
1370 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
1371 convert_to_wallclock(cp->expiry_time),
1372 kref_read(&cp->ref), cp->flags);
1373 cache_get(cp);
1374 if (cache_check(cd, cp, NULL))
1375 /* cache_check does a cache_put on failure */
1376 seq_printf(m, "# ");
1377 else {
1378 if (cache_is_expired(cd, cp))
1379 seq_printf(m, "# ");
1380 cache_put(cp, cd);
1383 return cd->cache_show(m, cd, cp);
1386 static const struct seq_operations cache_content_op = {
1387 .start = cache_seq_start,
1388 .next = cache_seq_next,
1389 .stop = cache_seq_stop,
1390 .show = c_show,
1393 static int content_open(struct inode *inode, struct file *file,
1394 struct cache_detail *cd)
1396 struct seq_file *seq;
1397 int err;
1399 if (!cd || !try_module_get(cd->owner))
1400 return -EACCES;
1402 err = seq_open(file, &cache_content_op);
1403 if (err) {
1404 module_put(cd->owner);
1405 return err;
1408 seq = file->private_data;
1409 seq->private = cd;
1410 return 0;
1413 static int content_release(struct inode *inode, struct file *file,
1414 struct cache_detail *cd)
1416 int ret = seq_release(inode, file);
1417 module_put(cd->owner);
1418 return ret;
1421 static int open_flush(struct inode *inode, struct file *file,
1422 struct cache_detail *cd)
1424 if (!cd || !try_module_get(cd->owner))
1425 return -EACCES;
1426 return nonseekable_open(inode, file);
1429 static int release_flush(struct inode *inode, struct file *file,
1430 struct cache_detail *cd)
1432 module_put(cd->owner);
1433 return 0;
1436 static ssize_t read_flush(struct file *file, char __user *buf,
1437 size_t count, loff_t *ppos,
1438 struct cache_detail *cd)
1440 char tbuf[22];
1441 size_t len;
1443 len = snprintf(tbuf, sizeof(tbuf), "%lu\n",
1444 convert_to_wallclock(cd->flush_time));
1445 return simple_read_from_buffer(buf, count, ppos, tbuf, len);
1448 static ssize_t write_flush(struct file *file, const char __user *buf,
1449 size_t count, loff_t *ppos,
1450 struct cache_detail *cd)
1452 char tbuf[20];
1453 char *bp, *ep;
1454 time_t then, now;
1456 if (*ppos || count > sizeof(tbuf)-1)
1457 return -EINVAL;
1458 if (copy_from_user(tbuf, buf, count))
1459 return -EFAULT;
1460 tbuf[count] = 0;
1461 simple_strtoul(tbuf, &ep, 0);
1462 if (*ep && *ep != '\n')
1463 return -EINVAL;
1465 bp = tbuf;
1466 then = get_expiry(&bp);
1467 now = seconds_since_boot();
1468 cd->nextcheck = now;
1469 /* Can only set flush_time to 1 second beyond "now", or
1470 * possibly 1 second beyond flushtime. This is because
1471 * flush_time never goes backwards so it mustn't get too far
1472 * ahead of time.
1474 if (then >= now) {
1475 /* Want to flush everything, so behave like cache_purge() */
1476 if (cd->flush_time >= now)
1477 now = cd->flush_time + 1;
1478 then = now;
1481 cd->flush_time = then;
1482 cache_flush();
1484 *ppos += count;
1485 return count;
1488 static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1489 size_t count, loff_t *ppos)
1491 struct cache_detail *cd = PDE_DATA(file_inode(filp));
1493 return cache_read(filp, buf, count, ppos, cd);
1496 static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1497 size_t count, loff_t *ppos)
1499 struct cache_detail *cd = PDE_DATA(file_inode(filp));
1501 return cache_write(filp, buf, count, ppos, cd);
1504 static __poll_t cache_poll_procfs(struct file *filp, poll_table *wait)
1506 struct cache_detail *cd = PDE_DATA(file_inode(filp));
1508 return cache_poll(filp, wait, cd);
1511 static long cache_ioctl_procfs(struct file *filp,
1512 unsigned int cmd, unsigned long arg)
1514 struct inode *inode = file_inode(filp);
1515 struct cache_detail *cd = PDE_DATA(inode);
1517 return cache_ioctl(inode, filp, cmd, arg, cd);
1520 static int cache_open_procfs(struct inode *inode, struct file *filp)
1522 struct cache_detail *cd = PDE_DATA(inode);
1524 return cache_open(inode, filp, cd);
1527 static int cache_release_procfs(struct inode *inode, struct file *filp)
1529 struct cache_detail *cd = PDE_DATA(inode);
1531 return cache_release(inode, filp, cd);
1534 static const struct file_operations cache_file_operations_procfs = {
1535 .owner = THIS_MODULE,
1536 .llseek = no_llseek,
1537 .read = cache_read_procfs,
1538 .write = cache_write_procfs,
1539 .poll = cache_poll_procfs,
1540 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
1541 .open = cache_open_procfs,
1542 .release = cache_release_procfs,
1545 static int content_open_procfs(struct inode *inode, struct file *filp)
1547 struct cache_detail *cd = PDE_DATA(inode);
1549 return content_open(inode, filp, cd);
1552 static int content_release_procfs(struct inode *inode, struct file *filp)
1554 struct cache_detail *cd = PDE_DATA(inode);
1556 return content_release(inode, filp, cd);
1559 static const struct file_operations content_file_operations_procfs = {
1560 .open = content_open_procfs,
1561 .read = seq_read,
1562 .llseek = seq_lseek,
1563 .release = content_release_procfs,
1566 static int open_flush_procfs(struct inode *inode, struct file *filp)
1568 struct cache_detail *cd = PDE_DATA(inode);
1570 return open_flush(inode, filp, cd);
1573 static int release_flush_procfs(struct inode *inode, struct file *filp)
1575 struct cache_detail *cd = PDE_DATA(inode);
1577 return release_flush(inode, filp, cd);
1580 static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1581 size_t count, loff_t *ppos)
1583 struct cache_detail *cd = PDE_DATA(file_inode(filp));
1585 return read_flush(filp, buf, count, ppos, cd);
1588 static ssize_t write_flush_procfs(struct file *filp,
1589 const char __user *buf,
1590 size_t count, loff_t *ppos)
1592 struct cache_detail *cd = PDE_DATA(file_inode(filp));
1594 return write_flush(filp, buf, count, ppos, cd);
1597 static const struct file_operations cache_flush_operations_procfs = {
1598 .open = open_flush_procfs,
1599 .read = read_flush_procfs,
1600 .write = write_flush_procfs,
1601 .release = release_flush_procfs,
1602 .llseek = no_llseek,
1605 static void remove_cache_proc_entries(struct cache_detail *cd)
1607 if (cd->procfs) {
1608 proc_remove(cd->procfs);
1609 cd->procfs = NULL;
1613 #ifdef CONFIG_PROC_FS
1614 static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
1616 struct proc_dir_entry *p;
1617 struct sunrpc_net *sn;
1619 sn = net_generic(net, sunrpc_net_id);
1620 cd->procfs = proc_mkdir(cd->name, sn->proc_net_rpc);
1621 if (cd->procfs == NULL)
1622 goto out_nomem;
1624 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1625 cd->procfs, &cache_flush_operations_procfs, cd);
1626 if (p == NULL)
1627 goto out_nomem;
1629 if (cd->cache_request || cd->cache_parse) {
1630 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1631 cd->procfs, &cache_file_operations_procfs, cd);
1632 if (p == NULL)
1633 goto out_nomem;
1635 if (cd->cache_show) {
1636 p = proc_create_data("content", S_IFREG|S_IRUSR,
1637 cd->procfs, &content_file_operations_procfs, cd);
1638 if (p == NULL)
1639 goto out_nomem;
1641 return 0;
1642 out_nomem:
1643 remove_cache_proc_entries(cd);
1644 return -ENOMEM;
1646 #else /* CONFIG_PROC_FS */
1647 static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
1649 return 0;
1651 #endif
1653 void __init cache_initialize(void)
1655 INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
1658 int cache_register_net(struct cache_detail *cd, struct net *net)
1660 int ret;
1662 sunrpc_init_cache_detail(cd);
1663 ret = create_cache_proc_entries(cd, net);
1664 if (ret)
1665 sunrpc_destroy_cache_detail(cd);
1666 return ret;
1668 EXPORT_SYMBOL_GPL(cache_register_net);
1670 void cache_unregister_net(struct cache_detail *cd, struct net *net)
1672 remove_cache_proc_entries(cd);
1673 sunrpc_destroy_cache_detail(cd);
1675 EXPORT_SYMBOL_GPL(cache_unregister_net);
1677 struct cache_detail *cache_create_net(const struct cache_detail *tmpl, struct net *net)
1679 struct cache_detail *cd;
1680 int i;
1682 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
1683 if (cd == NULL)
1684 return ERR_PTR(-ENOMEM);
1686 cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head),
1687 GFP_KERNEL);
1688 if (cd->hash_table == NULL) {
1689 kfree(cd);
1690 return ERR_PTR(-ENOMEM);
1693 for (i = 0; i < cd->hash_size; i++)
1694 INIT_HLIST_HEAD(&cd->hash_table[i]);
1695 cd->net = net;
1696 return cd;
1698 EXPORT_SYMBOL_GPL(cache_create_net);
1700 void cache_destroy_net(struct cache_detail *cd, struct net *net)
1702 kfree(cd->hash_table);
1703 kfree(cd);
1705 EXPORT_SYMBOL_GPL(cache_destroy_net);
1707 static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1708 size_t count, loff_t *ppos)
1710 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
1712 return cache_read(filp, buf, count, ppos, cd);
1715 static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1716 size_t count, loff_t *ppos)
1718 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
1720 return cache_write(filp, buf, count, ppos, cd);
1723 static __poll_t cache_poll_pipefs(struct file *filp, poll_table *wait)
1725 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
1727 return cache_poll(filp, wait, cd);
1730 static long cache_ioctl_pipefs(struct file *filp,
1731 unsigned int cmd, unsigned long arg)
1733 struct inode *inode = file_inode(filp);
1734 struct cache_detail *cd = RPC_I(inode)->private;
1736 return cache_ioctl(inode, filp, cmd, arg, cd);
1739 static int cache_open_pipefs(struct inode *inode, struct file *filp)
1741 struct cache_detail *cd = RPC_I(inode)->private;
1743 return cache_open(inode, filp, cd);
1746 static int cache_release_pipefs(struct inode *inode, struct file *filp)
1748 struct cache_detail *cd = RPC_I(inode)->private;
1750 return cache_release(inode, filp, cd);
1753 const struct file_operations cache_file_operations_pipefs = {
1754 .owner = THIS_MODULE,
1755 .llseek = no_llseek,
1756 .read = cache_read_pipefs,
1757 .write = cache_write_pipefs,
1758 .poll = cache_poll_pipefs,
1759 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
1760 .open = cache_open_pipefs,
1761 .release = cache_release_pipefs,
1764 static int content_open_pipefs(struct inode *inode, struct file *filp)
1766 struct cache_detail *cd = RPC_I(inode)->private;
1768 return content_open(inode, filp, cd);
1771 static int content_release_pipefs(struct inode *inode, struct file *filp)
1773 struct cache_detail *cd = RPC_I(inode)->private;
1775 return content_release(inode, filp, cd);
1778 const struct file_operations content_file_operations_pipefs = {
1779 .open = content_open_pipefs,
1780 .read = seq_read,
1781 .llseek = seq_lseek,
1782 .release = content_release_pipefs,
1785 static int open_flush_pipefs(struct inode *inode, struct file *filp)
1787 struct cache_detail *cd = RPC_I(inode)->private;
1789 return open_flush(inode, filp, cd);
1792 static int release_flush_pipefs(struct inode *inode, struct file *filp)
1794 struct cache_detail *cd = RPC_I(inode)->private;
1796 return release_flush(inode, filp, cd);
1799 static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1800 size_t count, loff_t *ppos)
1802 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
1804 return read_flush(filp, buf, count, ppos, cd);
1807 static ssize_t write_flush_pipefs(struct file *filp,
1808 const char __user *buf,
1809 size_t count, loff_t *ppos)
1811 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
1813 return write_flush(filp, buf, count, ppos, cd);
1816 const struct file_operations cache_flush_operations_pipefs = {
1817 .open = open_flush_pipefs,
1818 .read = read_flush_pipefs,
1819 .write = write_flush_pipefs,
1820 .release = release_flush_pipefs,
1821 .llseek = no_llseek,
1824 int sunrpc_cache_register_pipefs(struct dentry *parent,
1825 const char *name, umode_t umode,
1826 struct cache_detail *cd)
1828 struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd);
1829 if (IS_ERR(dir))
1830 return PTR_ERR(dir);
1831 cd->pipefs = dir;
1832 return 0;
1834 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1836 void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1838 if (cd->pipefs) {
1839 rpc_remove_cache_dir(cd->pipefs);
1840 cd->pipefs = NULL;
1843 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
1845 void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h)
1847 write_lock(&cd->hash_lock);
1848 if (!hlist_unhashed(&h->cache_list)){
1849 hlist_del_init(&h->cache_list);
1850 cd->entries--;
1851 write_unlock(&cd->hash_lock);
1852 cache_put(h, cd);
1853 } else
1854 write_unlock(&cd->hash_lock);
1856 EXPORT_SYMBOL_GPL(sunrpc_cache_unhash);