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>
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>
38 #define RPCDBG_FACILITY RPCDBG_CACHE
40 static int cache_defer_req(struct cache_req *req, struct cache_head *item);
41 static void cache_revisit_request(struct cache_head *item);
43 static void cache_init(struct cache_head *h)
45 time_t now = seconds_since_boot();
49 h->expiry_time = now + CACHE_NEW_EXPIRY;
50 h->last_refresh = now;
53 static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h)
55 return (h->expiry_time < seconds_since_boot()) ||
56 (detail->flush_time > h->last_refresh);
59 struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
60 struct cache_head *key, int hash)
62 struct cache_head **head, **hp;
63 struct cache_head *new = NULL, *freeme = NULL;
65 head = &detail->hash_table[hash];
67 read_lock(&detail->hash_lock);
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. */
76 read_unlock(&detail->hash_lock);
80 read_unlock(&detail->hash_lock);
81 /* Didn't find anything, insert an empty entry */
83 new = detail->alloc();
86 /* must fully initialise 'new', else
87 * we might get lose if we need to
91 detail->init(new, key);
93 write_lock(&detail->hash_lock);
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)) {
107 write_unlock(&detail->hash_lock);
108 cache_put(new, detail);
116 write_unlock(&detail->hash_lock);
119 cache_put(freeme, detail);
122 EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
125 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
127 static void cache_fresh_locked(struct cache_head *head, time_t expiry)
129 head->expiry_time = expiry;
130 head->last_refresh = seconds_since_boot();
131 set_bit(CACHE_VALID, &head->flags);
134 static void cache_fresh_unlocked(struct cache_head *head,
135 struct cache_detail *detail)
137 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
138 cache_revisit_request(head);
139 cache_dequeue(detail, head);
143 struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
144 struct cache_head *new, struct cache_head *old, int hash)
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
150 struct cache_head **head;
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);
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);
165 write_unlock(&detail->hash_lock);
167 /* We need to insert a new entry */
168 tmp = detail->alloc();
170 cache_put(old, detail);
174 detail->init(tmp, old);
175 head = &detail->hash_table[hash];
177 write_lock(&detail->hash_lock);
178 if (test_bit(CACHE_NEGATIVE, &new->flags))
179 set_bit(CACHE_NEGATIVE, &tmp->flags);
181 detail->update(tmp, new);
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);
194 EXPORT_SYMBOL_GPL(sunrpc_cache_update);
196 static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
198 if (!cd->cache_upcall)
200 return cd->cache_upcall(cd, h);
203 static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h)
205 if (!test_bit(CACHE_VALID, &h->flags))
209 if (test_bit(CACHE_NEGATIVE, &h->flags))
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.
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
230 int cache_check(struct cache_detail *detail,
231 struct cache_head *h, struct cache_req *rqstp)
234 long refresh_age, age;
236 /* First decide return status as best we can */
237 rv = cache_is_valid(detail, h);
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;
246 } else if (rv == -EAGAIN || age > refresh_age/2) {
247 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
249 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
250 switch (cache_make_upcall(detail, h)) {
252 clear_bit(CACHE_PENDING, &h->flags);
253 cache_revisit_request(h);
255 set_bit(CACHE_NEGATIVE, &h->flags);
256 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY);
257 cache_fresh_unlocked(h, detail);
263 clear_bit(CACHE_PENDING, &h->flags);
264 cache_revisit_request(h);
271 if (cache_defer_req(rqstp, h) < 0) {
272 /* Request is not deferred */
273 rv = cache_is_valid(detail, h);
279 cache_put(h, detail);
282 EXPORT_SYMBOL_GPL(cache_check);
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
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.
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
298 * later we might drop old entries with non-NEVER expiry if that table
299 * is getting 'full' for some definition of 'full'
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
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.
311 * A table is then only scanned if the current time is at least
312 * the nextcheck time.
316 static LIST_HEAD(cache_list);
317 static DEFINE_SPINLOCK(cache_list_lock);
318 static struct cache_detail *current_detail;
319 static int current_index;
321 static void do_cache_clean(struct work_struct *work);
322 static struct delayed_work cache_cleaner;
324 static void sunrpc_init_cache_detail(struct cache_detail *cd)
326 rwlock_init(&cd->hash_lock);
327 INIT_LIST_HEAD(&cd->queue);
328 spin_lock(&cache_list_lock);
331 atomic_set(&cd->readers, 0);
334 list_add(&cd->others, &cache_list);
335 spin_unlock(&cache_list_lock);
337 /* start the cleaning process */
338 schedule_delayed_work(&cache_cleaner, 0);
341 static void sunrpc_destroy_cache_detail(struct cache_detail *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);
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);
362 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
365 /* clean cache tries to find something to clean
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.
371 static int cache_clean(void)
374 struct list_head *next;
376 spin_lock(&cache_list_lock);
378 /* find a suitable table if we don't already have one */
379 while (current_detail == NULL ||
380 current_index >= current_detail->hash_size) {
382 next = current_detail->others.next;
384 next = cache_list.next;
385 if (next == &cache_list) {
386 current_detail = NULL;
387 spin_unlock(&cache_list_lock);
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;
395 current_detail->nextcheck = seconds_since_boot()+30*60;
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)
405 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
407 if (current_detail && current_index < current_detail->hash_size) {
408 struct cache_head *ch, **cp;
409 struct cache_detail *d;
411 write_lock(¤t_detail->hash_lock);
413 /* Ok, now to clean this strand */
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))
424 current_detail->entries--;
429 write_unlock(¤t_detail->hash_lock);
433 spin_unlock(&cache_list_lock);
435 if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
436 cache_dequeue(current_detail, ch);
437 cache_revisit_request(ch);
441 spin_unlock(&cache_list_lock);
447 * We want to regularly clean the cache, so we need to schedule some work ...
449 static void do_cache_clean(struct work_struct *work)
452 if (cache_clean() == -1)
453 delay = round_jiffies_relative(30*HZ);
455 if (list_empty(&cache_list))
459 schedule_delayed_work(&cache_cleaner, delay);
464 * Clean all caches promptly. This just calls cache_clean
465 * repeatedly until we are sure that every cache has had a chance to
468 void cache_flush(void)
470 while (cache_clean() != -1)
472 while (cache_clean() != -1)
475 EXPORT_SYMBOL_GPL(cache_flush);
477 void cache_purge(struct cache_detail *detail)
479 detail->flush_time = LONG_MAX;
480 detail->nextcheck = seconds_since_boot();
482 detail->flush_time = 1;
484 EXPORT_SYMBOL_GPL(cache_purge);
488 * Deferral and Revisiting of Requests.
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
502 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
503 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
505 #define DFR_MAX 300 /* ??? */
507 static DEFINE_SPINLOCK(cache_defer_lock);
508 static LIST_HEAD(cache_defer_list);
509 static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
510 static int cache_defer_cnt;
512 static void __unhash_deferred_req(struct cache_deferred_req *dreq)
514 list_del_init(&dreq->recent);
515 hlist_del_init(&dreq->hash);
519 static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
521 int hash = DFR_HASH(item);
523 list_add(&dreq->recent, &cache_defer_list);
524 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
527 static int setup_deferral(struct cache_deferred_req *dreq, struct cache_head *item)
529 struct cache_deferred_req *discard;
533 spin_lock(&cache_defer_lock);
535 __hash_deferred_req(dreq, item);
537 /* it is in, now maybe clean up */
539 if (++cache_defer_cnt > DFR_MAX) {
540 discard = list_entry(cache_defer_list.prev,
541 struct cache_deferred_req, recent);
542 __unhash_deferred_req(discard);
544 spin_unlock(&cache_defer_lock);
547 /* there was one too many */
548 discard->revisit(discard, 1);
550 if (!test_bit(CACHE_PENDING, &item->flags)) {
551 /* must have just been validated... */
552 cache_revisit_request(item);
558 struct thread_deferred_req {
559 struct cache_deferred_req handle;
560 struct completion completion;
563 static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
565 struct thread_deferred_req *dr =
566 container_of(dreq, struct thread_deferred_req, handle);
567 complete(&dr->completion);
570 static int cache_wait_req(struct cache_req *req, struct cache_head *item)
572 struct thread_deferred_req sleeper;
573 struct cache_deferred_req *dreq = &sleeper.handle;
576 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
577 dreq->revisit = cache_restart_thread;
579 ret = setup_deferral(dreq, item);
583 if (wait_for_completion_interruptible_timeout(
584 &sleeper.completion, req->thread_wait) <= 0) {
585 /* The completion wasn't completed, so we need
588 spin_lock(&cache_defer_lock);
589 if (!hlist_unhashed(&sleeper.handle.hash)) {
590 __unhash_deferred_req(&sleeper.handle);
591 spin_unlock(&cache_defer_lock);
593 /* cache_revisit_request already removed
594 * this from the hash table, but hasn't
595 * called ->revisit yet. It will very soon
596 * and we need to wait for it.
598 spin_unlock(&cache_defer_lock);
599 wait_for_completion(&sleeper.completion);
602 if (test_bit(CACHE_PENDING, &item->flags)) {
603 /* item is still pending, try request
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.
616 static int cache_defer_req(struct cache_req *req, struct cache_head *item)
618 struct cache_deferred_req *dreq;
621 if (cache_defer_cnt >= DFR_MAX) {
622 /* too much in the cache, randomly drop this one,
623 * or continue and drop the oldest
628 if (req->thread_wait) {
629 ret = cache_wait_req(req, item);
630 if (ret != -ETIMEDOUT)
633 dreq = req->defer(req);
636 return setup_deferral(dreq, item);
639 static void cache_revisit_request(struct cache_head *item)
641 struct cache_deferred_req *dreq;
642 struct list_head pending;
643 struct hlist_node *lp, *tmp;
644 int hash = DFR_HASH(item);
646 INIT_LIST_HEAD(&pending);
647 spin_lock(&cache_defer_lock);
649 hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash)
650 if (dreq->item == item) {
651 __unhash_deferred_req(dreq);
652 list_add(&dreq->recent, &pending);
655 spin_unlock(&cache_defer_lock);
657 while (!list_empty(&pending)) {
658 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
659 list_del_init(&dreq->recent);
660 dreq->revisit(dreq, 0);
664 void cache_clean_deferred(void *owner)
666 struct cache_deferred_req *dreq, *tmp;
667 struct list_head pending;
670 INIT_LIST_HEAD(&pending);
671 spin_lock(&cache_defer_lock);
673 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
674 if (dreq->owner == owner) {
675 __unhash_deferred_req(dreq);
676 list_add(&dreq->recent, &pending);
679 spin_unlock(&cache_defer_lock);
681 while (!list_empty(&pending)) {
682 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
683 list_del_init(&dreq->recent);
684 dreq->revisit(dreq, 1);
689 * communicate with user-space
691 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
692 * On read, you get a full request, or block.
693 * On write, an update request is processed.
694 * Poll works if anything to read, and always allows write.
696 * Implemented by linked list of requests. Each open file has
697 * a ->private that also exists in this list. New requests are added
698 * to the end and may wakeup and preceding readers.
699 * New readers are added to the head. If, on read, an item is found with
700 * CACHE_UPCALLING clear, we free it from the list.
704 static DEFINE_SPINLOCK(queue_lock);
705 static DEFINE_MUTEX(queue_io_mutex);
708 struct list_head list;
709 int reader; /* if 0, then request */
711 struct cache_request {
712 struct cache_queue q;
713 struct cache_head *item;
718 struct cache_reader {
719 struct cache_queue q;
720 int offset; /* if non-0, we have a refcnt on next request */
723 static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
724 loff_t *ppos, struct cache_detail *cd)
726 struct cache_reader *rp = filp->private_data;
727 struct cache_request *rq;
728 struct inode *inode = filp->f_path.dentry->d_inode;
734 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent
735 * readers on this file */
737 spin_lock(&queue_lock);
738 /* need to find next request */
739 while (rp->q.list.next != &cd->queue &&
740 list_entry(rp->q.list.next, struct cache_queue, list)
742 struct list_head *next = rp->q.list.next;
743 list_move(&rp->q.list, next);
745 if (rp->q.list.next == &cd->queue) {
746 spin_unlock(&queue_lock);
747 mutex_unlock(&inode->i_mutex);
751 rq = container_of(rp->q.list.next, struct cache_request, q.list);
752 BUG_ON(rq->q.reader);
755 spin_unlock(&queue_lock);
757 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
759 spin_lock(&queue_lock);
760 list_move(&rp->q.list, &rq->q.list);
761 spin_unlock(&queue_lock);
763 if (rp->offset + count > rq->len)
764 count = rq->len - rp->offset;
766 if (copy_to_user(buf, rq->buf + rp->offset, count))
769 if (rp->offset >= rq->len) {
771 spin_lock(&queue_lock);
772 list_move(&rp->q.list, &rq->q.list);
773 spin_unlock(&queue_lock);
778 if (rp->offset == 0) {
779 /* need to release rq */
780 spin_lock(&queue_lock);
782 if (rq->readers == 0 &&
783 !test_bit(CACHE_PENDING, &rq->item->flags)) {
784 list_del(&rq->q.list);
785 spin_unlock(&queue_lock);
786 cache_put(rq->item, cd);
790 spin_unlock(&queue_lock);
794 mutex_unlock(&inode->i_mutex);
795 return err ? err : count;
798 static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
799 size_t count, struct cache_detail *cd)
803 if (copy_from_user(kaddr, buf, count))
806 ret = cd->cache_parse(cd, kaddr, count);
812 static ssize_t cache_slow_downcall(const char __user *buf,
813 size_t count, struct cache_detail *cd)
815 static char write_buf[8192]; /* protected by queue_io_mutex */
816 ssize_t ret = -EINVAL;
818 if (count >= sizeof(write_buf))
820 mutex_lock(&queue_io_mutex);
821 ret = cache_do_downcall(write_buf, buf, count, cd);
822 mutex_unlock(&queue_io_mutex);
827 static ssize_t cache_downcall(struct address_space *mapping,
828 const char __user *buf,
829 size_t count, struct cache_detail *cd)
833 ssize_t ret = -ENOMEM;
835 if (count >= PAGE_CACHE_SIZE)
838 page = find_or_create_page(mapping, 0, GFP_KERNEL);
843 ret = cache_do_downcall(kaddr, buf, count, cd);
846 page_cache_release(page);
849 return cache_slow_downcall(buf, count, cd);
852 static ssize_t cache_write(struct file *filp, const char __user *buf,
853 size_t count, loff_t *ppos,
854 struct cache_detail *cd)
856 struct address_space *mapping = filp->f_mapping;
857 struct inode *inode = filp->f_path.dentry->d_inode;
858 ssize_t ret = -EINVAL;
860 if (!cd->cache_parse)
863 mutex_lock(&inode->i_mutex);
864 ret = cache_downcall(mapping, buf, count, cd);
865 mutex_unlock(&inode->i_mutex);
870 static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
872 static unsigned int cache_poll(struct file *filp, poll_table *wait,
873 struct cache_detail *cd)
876 struct cache_reader *rp = filp->private_data;
877 struct cache_queue *cq;
879 poll_wait(filp, &queue_wait, wait);
881 /* alway allow write */
882 mask = POLL_OUT | POLLWRNORM;
887 spin_lock(&queue_lock);
889 for (cq= &rp->q; &cq->list != &cd->queue;
890 cq = list_entry(cq->list.next, struct cache_queue, list))
892 mask |= POLLIN | POLLRDNORM;
895 spin_unlock(&queue_lock);
899 static int cache_ioctl(struct inode *ino, struct file *filp,
900 unsigned int cmd, unsigned long arg,
901 struct cache_detail *cd)
904 struct cache_reader *rp = filp->private_data;
905 struct cache_queue *cq;
907 if (cmd != FIONREAD || !rp)
910 spin_lock(&queue_lock);
912 /* only find the length remaining in current request,
913 * or the length of the next request
915 for (cq= &rp->q; &cq->list != &cd->queue;
916 cq = list_entry(cq->list.next, struct cache_queue, list))
918 struct cache_request *cr =
919 container_of(cq, struct cache_request, q);
920 len = cr->len - rp->offset;
923 spin_unlock(&queue_lock);
925 return put_user(len, (int __user *)arg);
928 static int cache_open(struct inode *inode, struct file *filp,
929 struct cache_detail *cd)
931 struct cache_reader *rp = NULL;
933 if (!cd || !try_module_get(cd->owner))
935 nonseekable_open(inode, filp);
936 if (filp->f_mode & FMODE_READ) {
937 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
942 atomic_inc(&cd->readers);
943 spin_lock(&queue_lock);
944 list_add(&rp->q.list, &cd->queue);
945 spin_unlock(&queue_lock);
947 filp->private_data = rp;
951 static int cache_release(struct inode *inode, struct file *filp,
952 struct cache_detail *cd)
954 struct cache_reader *rp = filp->private_data;
957 spin_lock(&queue_lock);
959 struct cache_queue *cq;
960 for (cq= &rp->q; &cq->list != &cd->queue;
961 cq = list_entry(cq->list.next, struct cache_queue, list))
963 container_of(cq, struct cache_request, q)
969 list_del(&rp->q.list);
970 spin_unlock(&queue_lock);
972 filp->private_data = NULL;
975 cd->last_close = seconds_since_boot();
976 atomic_dec(&cd->readers);
978 module_put(cd->owner);
984 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
986 struct cache_queue *cq;
987 spin_lock(&queue_lock);
988 list_for_each_entry(cq, &detail->queue, list)
990 struct cache_request *cr = container_of(cq, struct cache_request, q);
993 if (cr->readers != 0)
995 list_del(&cr->q.list);
996 spin_unlock(&queue_lock);
997 cache_put(cr->item, detail);
1002 spin_unlock(&queue_lock);
1006 * Support routines for text-based upcalls.
1007 * Fields are separated by spaces.
1008 * Fields are either mangled to quote space tab newline slosh with slosh
1009 * or a hexified with a leading \x
1010 * Record is terminated with newline.
1014 void qword_add(char **bpp, int *lp, char *str)
1020 if (len < 0) return;
1022 while ((c=*str++) && len)
1030 *bp++ = '0' + ((c & 0300)>>6);
1031 *bp++ = '0' + ((c & 0070)>>3);
1032 *bp++ = '0' + ((c & 0007)>>0);
1040 if (c || len <1) len = -1;
1048 EXPORT_SYMBOL_GPL(qword_add);
1050 void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1055 if (len < 0) return;
1061 while (blen && len >= 2) {
1062 unsigned char c = *buf++;
1063 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
1064 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
1069 if (blen || len<1) len = -1;
1077 EXPORT_SYMBOL_GPL(qword_addhex);
1079 static void warn_no_listener(struct cache_detail *detail)
1081 if (detail->last_warn != detail->last_close) {
1082 detail->last_warn = detail->last_close;
1083 if (detail->warn_no_listener)
1084 detail->warn_no_listener(detail, detail->last_close != 0);
1088 static bool cache_listeners_exist(struct cache_detail *detail)
1090 if (atomic_read(&detail->readers))
1092 if (detail->last_close == 0)
1093 /* This cache was never opened */
1095 if (detail->last_close < seconds_since_boot() - 30)
1097 * We allow for the possibility that someone might
1098 * restart a userspace daemon without restarting the
1099 * server; but after 30 seconds, we give up.
1106 * register an upcall request to user-space and queue it up for read() by the
1109 * Each request is at most one page long.
1111 int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
1112 void (*cache_request)(struct cache_detail *,
1113 struct cache_head *,
1119 struct cache_request *crq;
1123 if (!cache_listeners_exist(detail)) {
1124 warn_no_listener(detail);
1128 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1132 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1138 bp = buf; len = PAGE_SIZE;
1140 cache_request(detail, h, &bp, &len);
1148 crq->item = cache_get(h);
1150 crq->len = PAGE_SIZE - len;
1152 spin_lock(&queue_lock);
1153 list_add_tail(&crq->q.list, &detail->queue);
1154 spin_unlock(&queue_lock);
1155 wake_up(&queue_wait);
1158 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
1161 * parse a message from user-space and pass it
1162 * to an appropriate cache
1163 * Messages are, like requests, separated into fields by
1164 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1167 * reply cachename expiry key ... content....
1169 * key and content are both parsed by cache
1172 #define isodigit(c) (isdigit(c) && c <= '7')
1173 int qword_get(char **bpp, char *dest, int bufsize)
1175 /* return bytes copied, or -1 on error */
1179 while (*bp == ' ') bp++;
1181 if (bp[0] == '\\' && bp[1] == 'x') {
1184 while (len < bufsize) {
1187 h = hex_to_bin(bp[0]);
1191 l = hex_to_bin(bp[1]);
1195 *dest++ = (h << 4) | l;
1200 /* text with \nnn octal quoting */
1201 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1203 isodigit(bp[1]) && (bp[1] <= '3') &&
1206 int byte = (*++bp -'0');
1208 byte = (byte << 3) | (*bp++ - '0');
1209 byte = (byte << 3) | (*bp++ - '0');
1219 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1221 while (*bp == ' ') bp++;
1226 EXPORT_SYMBOL_GPL(qword_get);
1230 * support /proc/sunrpc/cache/$CACHENAME/content
1232 * We call ->cache_show passing NULL for the item to
1233 * get a header, then pass each real item in the cache
1237 struct cache_detail *cd;
1240 static void *c_start(struct seq_file *m, loff_t *pos)
1241 __acquires(cd->hash_lock)
1244 unsigned hash, entry;
1245 struct cache_head *ch;
1246 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1249 read_lock(&cd->hash_lock);
1251 return SEQ_START_TOKEN;
1253 entry = n & ((1LL<<32) - 1);
1255 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1258 n &= ~((1LL<<32) - 1);
1262 } while(hash < cd->hash_size &&
1263 cd->hash_table[hash]==NULL);
1264 if (hash >= cd->hash_size)
1267 return cd->hash_table[hash];
1270 static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1272 struct cache_head *ch = p;
1273 int hash = (*pos >> 32);
1274 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1276 if (p == SEQ_START_TOKEN)
1278 else if (ch->next == NULL) {
1285 *pos &= ~((1LL<<32) - 1);
1286 while (hash < cd->hash_size &&
1287 cd->hash_table[hash] == NULL) {
1291 if (hash >= cd->hash_size)
1294 return cd->hash_table[hash];
1297 static void c_stop(struct seq_file *m, void *p)
1298 __releases(cd->hash_lock)
1300 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1301 read_unlock(&cd->hash_lock);
1304 static int c_show(struct seq_file *m, void *p)
1306 struct cache_head *cp = p;
1307 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1309 if (p == SEQ_START_TOKEN)
1310 return cd->cache_show(m, cd, NULL);
1313 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
1314 convert_to_wallclock(cp->expiry_time),
1315 atomic_read(&cp->ref.refcount), cp->flags);
1317 if (cache_check(cd, cp, NULL))
1318 /* cache_check does a cache_put on failure */
1319 seq_printf(m, "# ");
1323 return cd->cache_show(m, cd, cp);
1326 static const struct seq_operations cache_content_op = {
1333 static int content_open(struct inode *inode, struct file *file,
1334 struct cache_detail *cd)
1338 if (!cd || !try_module_get(cd->owner))
1340 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
1342 module_put(cd->owner);
1350 static int content_release(struct inode *inode, struct file *file,
1351 struct cache_detail *cd)
1353 int ret = seq_release_private(inode, file);
1354 module_put(cd->owner);
1358 static int open_flush(struct inode *inode, struct file *file,
1359 struct cache_detail *cd)
1361 if (!cd || !try_module_get(cd->owner))
1363 return nonseekable_open(inode, file);
1366 static int release_flush(struct inode *inode, struct file *file,
1367 struct cache_detail *cd)
1369 module_put(cd->owner);
1373 static ssize_t read_flush(struct file *file, char __user *buf,
1374 size_t count, loff_t *ppos,
1375 struct cache_detail *cd)
1378 unsigned long p = *ppos;
1381 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time));
1388 if (copy_to_user(buf, (void*)(tbuf+p), len))
1394 static ssize_t write_flush(struct file *file, const char __user *buf,
1395 size_t count, loff_t *ppos,
1396 struct cache_detail *cd)
1401 if (*ppos || count > sizeof(tbuf)-1)
1403 if (copy_from_user(tbuf, buf, count))
1406 simple_strtoul(tbuf, &ep, 0);
1407 if (*ep && *ep != '\n')
1411 cd->flush_time = get_expiry(&bp);
1412 cd->nextcheck = seconds_since_boot();
1419 static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1420 size_t count, loff_t *ppos)
1422 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1424 return cache_read(filp, buf, count, ppos, cd);
1427 static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1428 size_t count, loff_t *ppos)
1430 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1432 return cache_write(filp, buf, count, ppos, cd);
1435 static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1437 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1439 return cache_poll(filp, wait, cd);
1442 static long cache_ioctl_procfs(struct file *filp,
1443 unsigned int cmd, unsigned long arg)
1446 struct inode *inode = filp->f_path.dentry->d_inode;
1447 struct cache_detail *cd = PDE(inode)->data;
1450 ret = cache_ioctl(inode, filp, cmd, arg, cd);
1456 static int cache_open_procfs(struct inode *inode, struct file *filp)
1458 struct cache_detail *cd = PDE(inode)->data;
1460 return cache_open(inode, filp, cd);
1463 static int cache_release_procfs(struct inode *inode, struct file *filp)
1465 struct cache_detail *cd = PDE(inode)->data;
1467 return cache_release(inode, filp, cd);
1470 static const struct file_operations cache_file_operations_procfs = {
1471 .owner = THIS_MODULE,
1472 .llseek = no_llseek,
1473 .read = cache_read_procfs,
1474 .write = cache_write_procfs,
1475 .poll = cache_poll_procfs,
1476 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
1477 .open = cache_open_procfs,
1478 .release = cache_release_procfs,
1481 static int content_open_procfs(struct inode *inode, struct file *filp)
1483 struct cache_detail *cd = PDE(inode)->data;
1485 return content_open(inode, filp, cd);
1488 static int content_release_procfs(struct inode *inode, struct file *filp)
1490 struct cache_detail *cd = PDE(inode)->data;
1492 return content_release(inode, filp, cd);
1495 static const struct file_operations content_file_operations_procfs = {
1496 .open = content_open_procfs,
1498 .llseek = seq_lseek,
1499 .release = content_release_procfs,
1502 static int open_flush_procfs(struct inode *inode, struct file *filp)
1504 struct cache_detail *cd = PDE(inode)->data;
1506 return open_flush(inode, filp, cd);
1509 static int release_flush_procfs(struct inode *inode, struct file *filp)
1511 struct cache_detail *cd = PDE(inode)->data;
1513 return release_flush(inode, filp, cd);
1516 static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1517 size_t count, loff_t *ppos)
1519 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1521 return read_flush(filp, buf, count, ppos, cd);
1524 static ssize_t write_flush_procfs(struct file *filp,
1525 const char __user *buf,
1526 size_t count, loff_t *ppos)
1528 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1530 return write_flush(filp, buf, count, ppos, cd);
1533 static const struct file_operations cache_flush_operations_procfs = {
1534 .open = open_flush_procfs,
1535 .read = read_flush_procfs,
1536 .write = write_flush_procfs,
1537 .release = release_flush_procfs,
1540 static void remove_cache_proc_entries(struct cache_detail *cd)
1542 if (cd->u.procfs.proc_ent == NULL)
1544 if (cd->u.procfs.flush_ent)
1545 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1546 if (cd->u.procfs.channel_ent)
1547 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1548 if (cd->u.procfs.content_ent)
1549 remove_proc_entry("content", cd->u.procfs.proc_ent);
1550 cd->u.procfs.proc_ent = NULL;
1551 remove_proc_entry(cd->name, proc_net_rpc);
1554 #ifdef CONFIG_PROC_FS
1555 static int create_cache_proc_entries(struct cache_detail *cd)
1557 struct proc_dir_entry *p;
1559 cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc);
1560 if (cd->u.procfs.proc_ent == NULL)
1562 cd->u.procfs.channel_ent = NULL;
1563 cd->u.procfs.content_ent = NULL;
1565 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1566 cd->u.procfs.proc_ent,
1567 &cache_flush_operations_procfs, cd);
1568 cd->u.procfs.flush_ent = p;
1572 if (cd->cache_upcall || cd->cache_parse) {
1573 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1574 cd->u.procfs.proc_ent,
1575 &cache_file_operations_procfs, cd);
1576 cd->u.procfs.channel_ent = p;
1580 if (cd->cache_show) {
1581 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
1582 cd->u.procfs.proc_ent,
1583 &content_file_operations_procfs, cd);
1584 cd->u.procfs.content_ent = p;
1590 remove_cache_proc_entries(cd);
1593 #else /* CONFIG_PROC_FS */
1594 static int create_cache_proc_entries(struct cache_detail *cd)
1600 void __init cache_initialize(void)
1602 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean);
1605 int cache_register(struct cache_detail *cd)
1609 sunrpc_init_cache_detail(cd);
1610 ret = create_cache_proc_entries(cd);
1612 sunrpc_destroy_cache_detail(cd);
1615 EXPORT_SYMBOL_GPL(cache_register);
1617 void cache_unregister(struct cache_detail *cd)
1619 remove_cache_proc_entries(cd);
1620 sunrpc_destroy_cache_detail(cd);
1622 EXPORT_SYMBOL_GPL(cache_unregister);
1624 static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1625 size_t count, loff_t *ppos)
1627 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1629 return cache_read(filp, buf, count, ppos, cd);
1632 static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1633 size_t count, loff_t *ppos)
1635 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1637 return cache_write(filp, buf, count, ppos, cd);
1640 static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1642 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1644 return cache_poll(filp, wait, cd);
1647 static long cache_ioctl_pipefs(struct file *filp,
1648 unsigned int cmd, unsigned long arg)
1650 struct inode *inode = filp->f_dentry->d_inode;
1651 struct cache_detail *cd = RPC_I(inode)->private;
1655 ret = cache_ioctl(inode, filp, cmd, arg, cd);
1661 static int cache_open_pipefs(struct inode *inode, struct file *filp)
1663 struct cache_detail *cd = RPC_I(inode)->private;
1665 return cache_open(inode, filp, cd);
1668 static int cache_release_pipefs(struct inode *inode, struct file *filp)
1670 struct cache_detail *cd = RPC_I(inode)->private;
1672 return cache_release(inode, filp, cd);
1675 const struct file_operations cache_file_operations_pipefs = {
1676 .owner = THIS_MODULE,
1677 .llseek = no_llseek,
1678 .read = cache_read_pipefs,
1679 .write = cache_write_pipefs,
1680 .poll = cache_poll_pipefs,
1681 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
1682 .open = cache_open_pipefs,
1683 .release = cache_release_pipefs,
1686 static int content_open_pipefs(struct inode *inode, struct file *filp)
1688 struct cache_detail *cd = RPC_I(inode)->private;
1690 return content_open(inode, filp, cd);
1693 static int content_release_pipefs(struct inode *inode, struct file *filp)
1695 struct cache_detail *cd = RPC_I(inode)->private;
1697 return content_release(inode, filp, cd);
1700 const struct file_operations content_file_operations_pipefs = {
1701 .open = content_open_pipefs,
1703 .llseek = seq_lseek,
1704 .release = content_release_pipefs,
1707 static int open_flush_pipefs(struct inode *inode, struct file *filp)
1709 struct cache_detail *cd = RPC_I(inode)->private;
1711 return open_flush(inode, filp, cd);
1714 static int release_flush_pipefs(struct inode *inode, struct file *filp)
1716 struct cache_detail *cd = RPC_I(inode)->private;
1718 return release_flush(inode, filp, cd);
1721 static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1722 size_t count, loff_t *ppos)
1724 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1726 return read_flush(filp, buf, count, ppos, cd);
1729 static ssize_t write_flush_pipefs(struct file *filp,
1730 const char __user *buf,
1731 size_t count, loff_t *ppos)
1733 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1735 return write_flush(filp, buf, count, ppos, cd);
1738 const struct file_operations cache_flush_operations_pipefs = {
1739 .open = open_flush_pipefs,
1740 .read = read_flush_pipefs,
1741 .write = write_flush_pipefs,
1742 .release = release_flush_pipefs,
1745 int sunrpc_cache_register_pipefs(struct dentry *parent,
1746 const char *name, mode_t umode,
1747 struct cache_detail *cd)
1753 sunrpc_init_cache_detail(cd);
1755 q.len = strlen(name);
1756 q.hash = full_name_hash(q.name, q.len);
1757 dir = rpc_create_cache_dir(parent, &q, umode, cd);
1759 cd->u.pipefs.dir = dir;
1761 sunrpc_destroy_cache_detail(cd);
1766 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1768 void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1770 rpc_remove_cache_dir(cd->u.pipefs.dir);
1771 cd->u.pipefs.dir = NULL;
1772 sunrpc_destroy_cache_detail(cd);
1774 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);