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);
677 spin_unlock(&cache_defer_lock);
679 while (!list_empty(&pending)) {
680 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
681 list_del_init(&dreq->recent);
682 dreq->revisit(dreq, 1);
687 * communicate with user-space
689 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
690 * On read, you get a full request, or block.
691 * On write, an update request is processed.
692 * Poll works if anything to read, and always allows write.
694 * Implemented by linked list of requests. Each open file has
695 * a ->private that also exists in this list. New requests are added
696 * to the end and may wakeup and preceding readers.
697 * New readers are added to the head. If, on read, an item is found with
698 * CACHE_UPCALLING clear, we free it from the list.
702 static DEFINE_SPINLOCK(queue_lock);
703 static DEFINE_MUTEX(queue_io_mutex);
706 struct list_head list;
707 int reader; /* if 0, then request */
709 struct cache_request {
710 struct cache_queue q;
711 struct cache_head *item;
716 struct cache_reader {
717 struct cache_queue q;
718 int offset; /* if non-0, we have a refcnt on next request */
721 static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
722 loff_t *ppos, struct cache_detail *cd)
724 struct cache_reader *rp = filp->private_data;
725 struct cache_request *rq;
726 struct inode *inode = filp->f_path.dentry->d_inode;
732 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent
733 * readers on this file */
735 spin_lock(&queue_lock);
736 /* need to find next request */
737 while (rp->q.list.next != &cd->queue &&
738 list_entry(rp->q.list.next, struct cache_queue, list)
740 struct list_head *next = rp->q.list.next;
741 list_move(&rp->q.list, next);
743 if (rp->q.list.next == &cd->queue) {
744 spin_unlock(&queue_lock);
745 mutex_unlock(&inode->i_mutex);
749 rq = container_of(rp->q.list.next, struct cache_request, q.list);
750 BUG_ON(rq->q.reader);
753 spin_unlock(&queue_lock);
755 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
757 spin_lock(&queue_lock);
758 list_move(&rp->q.list, &rq->q.list);
759 spin_unlock(&queue_lock);
761 if (rp->offset + count > rq->len)
762 count = rq->len - rp->offset;
764 if (copy_to_user(buf, rq->buf + rp->offset, count))
767 if (rp->offset >= rq->len) {
769 spin_lock(&queue_lock);
770 list_move(&rp->q.list, &rq->q.list);
771 spin_unlock(&queue_lock);
776 if (rp->offset == 0) {
777 /* need to release rq */
778 spin_lock(&queue_lock);
780 if (rq->readers == 0 &&
781 !test_bit(CACHE_PENDING, &rq->item->flags)) {
782 list_del(&rq->q.list);
783 spin_unlock(&queue_lock);
784 cache_put(rq->item, cd);
788 spin_unlock(&queue_lock);
792 mutex_unlock(&inode->i_mutex);
793 return err ? err : count;
796 static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
797 size_t count, struct cache_detail *cd)
801 if (copy_from_user(kaddr, buf, count))
804 ret = cd->cache_parse(cd, kaddr, count);
810 static ssize_t cache_slow_downcall(const char __user *buf,
811 size_t count, struct cache_detail *cd)
813 static char write_buf[8192]; /* protected by queue_io_mutex */
814 ssize_t ret = -EINVAL;
816 if (count >= sizeof(write_buf))
818 mutex_lock(&queue_io_mutex);
819 ret = cache_do_downcall(write_buf, buf, count, cd);
820 mutex_unlock(&queue_io_mutex);
825 static ssize_t cache_downcall(struct address_space *mapping,
826 const char __user *buf,
827 size_t count, struct cache_detail *cd)
831 ssize_t ret = -ENOMEM;
833 if (count >= PAGE_CACHE_SIZE)
836 page = find_or_create_page(mapping, 0, GFP_KERNEL);
841 ret = cache_do_downcall(kaddr, buf, count, cd);
844 page_cache_release(page);
847 return cache_slow_downcall(buf, count, cd);
850 static ssize_t cache_write(struct file *filp, const char __user *buf,
851 size_t count, loff_t *ppos,
852 struct cache_detail *cd)
854 struct address_space *mapping = filp->f_mapping;
855 struct inode *inode = filp->f_path.dentry->d_inode;
856 ssize_t ret = -EINVAL;
858 if (!cd->cache_parse)
861 mutex_lock(&inode->i_mutex);
862 ret = cache_downcall(mapping, buf, count, cd);
863 mutex_unlock(&inode->i_mutex);
868 static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
870 static unsigned int cache_poll(struct file *filp, poll_table *wait,
871 struct cache_detail *cd)
874 struct cache_reader *rp = filp->private_data;
875 struct cache_queue *cq;
877 poll_wait(filp, &queue_wait, wait);
879 /* alway allow write */
880 mask = POLL_OUT | POLLWRNORM;
885 spin_lock(&queue_lock);
887 for (cq= &rp->q; &cq->list != &cd->queue;
888 cq = list_entry(cq->list.next, struct cache_queue, list))
890 mask |= POLLIN | POLLRDNORM;
893 spin_unlock(&queue_lock);
897 static int cache_ioctl(struct inode *ino, struct file *filp,
898 unsigned int cmd, unsigned long arg,
899 struct cache_detail *cd)
902 struct cache_reader *rp = filp->private_data;
903 struct cache_queue *cq;
905 if (cmd != FIONREAD || !rp)
908 spin_lock(&queue_lock);
910 /* only find the length remaining in current request,
911 * or the length of the next request
913 for (cq= &rp->q; &cq->list != &cd->queue;
914 cq = list_entry(cq->list.next, struct cache_queue, list))
916 struct cache_request *cr =
917 container_of(cq, struct cache_request, q);
918 len = cr->len - rp->offset;
921 spin_unlock(&queue_lock);
923 return put_user(len, (int __user *)arg);
926 static int cache_open(struct inode *inode, struct file *filp,
927 struct cache_detail *cd)
929 struct cache_reader *rp = NULL;
931 if (!cd || !try_module_get(cd->owner))
933 nonseekable_open(inode, filp);
934 if (filp->f_mode & FMODE_READ) {
935 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
940 atomic_inc(&cd->readers);
941 spin_lock(&queue_lock);
942 list_add(&rp->q.list, &cd->queue);
943 spin_unlock(&queue_lock);
945 filp->private_data = rp;
949 static int cache_release(struct inode *inode, struct file *filp,
950 struct cache_detail *cd)
952 struct cache_reader *rp = filp->private_data;
955 spin_lock(&queue_lock);
957 struct cache_queue *cq;
958 for (cq= &rp->q; &cq->list != &cd->queue;
959 cq = list_entry(cq->list.next, struct cache_queue, list))
961 container_of(cq, struct cache_request, q)
967 list_del(&rp->q.list);
968 spin_unlock(&queue_lock);
970 filp->private_data = NULL;
973 cd->last_close = seconds_since_boot();
974 atomic_dec(&cd->readers);
976 module_put(cd->owner);
982 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
984 struct cache_queue *cq;
985 spin_lock(&queue_lock);
986 list_for_each_entry(cq, &detail->queue, list)
988 struct cache_request *cr = container_of(cq, struct cache_request, q);
991 if (cr->readers != 0)
993 list_del(&cr->q.list);
994 spin_unlock(&queue_lock);
995 cache_put(cr->item, detail);
1000 spin_unlock(&queue_lock);
1004 * Support routines for text-based upcalls.
1005 * Fields are separated by spaces.
1006 * Fields are either mangled to quote space tab newline slosh with slosh
1007 * or a hexified with a leading \x
1008 * Record is terminated with newline.
1012 void qword_add(char **bpp, int *lp, char *str)
1018 if (len < 0) return;
1020 while ((c=*str++) && len)
1028 *bp++ = '0' + ((c & 0300)>>6);
1029 *bp++ = '0' + ((c & 0070)>>3);
1030 *bp++ = '0' + ((c & 0007)>>0);
1038 if (c || len <1) len = -1;
1046 EXPORT_SYMBOL_GPL(qword_add);
1048 void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1053 if (len < 0) return;
1059 while (blen && len >= 2) {
1060 unsigned char c = *buf++;
1061 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
1062 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
1067 if (blen || len<1) len = -1;
1075 EXPORT_SYMBOL_GPL(qword_addhex);
1077 static void warn_no_listener(struct cache_detail *detail)
1079 if (detail->last_warn != detail->last_close) {
1080 detail->last_warn = detail->last_close;
1081 if (detail->warn_no_listener)
1082 detail->warn_no_listener(detail, detail->last_close != 0);
1086 static bool cache_listeners_exist(struct cache_detail *detail)
1088 if (atomic_read(&detail->readers))
1090 if (detail->last_close == 0)
1091 /* This cache was never opened */
1093 if (detail->last_close < seconds_since_boot() - 30)
1095 * We allow for the possibility that someone might
1096 * restart a userspace daemon without restarting the
1097 * server; but after 30 seconds, we give up.
1104 * register an upcall request to user-space and queue it up for read() by the
1107 * Each request is at most one page long.
1109 int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
1110 void (*cache_request)(struct cache_detail *,
1111 struct cache_head *,
1117 struct cache_request *crq;
1121 if (!cache_listeners_exist(detail)) {
1122 warn_no_listener(detail);
1126 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1130 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1136 bp = buf; len = PAGE_SIZE;
1138 cache_request(detail, h, &bp, &len);
1146 crq->item = cache_get(h);
1148 crq->len = PAGE_SIZE - len;
1150 spin_lock(&queue_lock);
1151 list_add_tail(&crq->q.list, &detail->queue);
1152 spin_unlock(&queue_lock);
1153 wake_up(&queue_wait);
1156 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
1159 * parse a message from user-space and pass it
1160 * to an appropriate cache
1161 * Messages are, like requests, separated into fields by
1162 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1165 * reply cachename expiry key ... content....
1167 * key and content are both parsed by cache
1170 #define isodigit(c) (isdigit(c) && c <= '7')
1171 int qword_get(char **bpp, char *dest, int bufsize)
1173 /* return bytes copied, or -1 on error */
1177 while (*bp == ' ') bp++;
1179 if (bp[0] == '\\' && bp[1] == 'x') {
1182 while (len < bufsize) {
1185 h = hex_to_bin(bp[0]);
1189 l = hex_to_bin(bp[1]);
1193 *dest++ = (h << 4) | l;
1198 /* text with \nnn octal quoting */
1199 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1201 isodigit(bp[1]) && (bp[1] <= '3') &&
1204 int byte = (*++bp -'0');
1206 byte = (byte << 3) | (*bp++ - '0');
1207 byte = (byte << 3) | (*bp++ - '0');
1217 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1219 while (*bp == ' ') bp++;
1224 EXPORT_SYMBOL_GPL(qword_get);
1228 * support /proc/sunrpc/cache/$CACHENAME/content
1230 * We call ->cache_show passing NULL for the item to
1231 * get a header, then pass each real item in the cache
1235 struct cache_detail *cd;
1238 static void *c_start(struct seq_file *m, loff_t *pos)
1239 __acquires(cd->hash_lock)
1242 unsigned hash, entry;
1243 struct cache_head *ch;
1244 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1247 read_lock(&cd->hash_lock);
1249 return SEQ_START_TOKEN;
1251 entry = n & ((1LL<<32) - 1);
1253 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1256 n &= ~((1LL<<32) - 1);
1260 } while(hash < cd->hash_size &&
1261 cd->hash_table[hash]==NULL);
1262 if (hash >= cd->hash_size)
1265 return cd->hash_table[hash];
1268 static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1270 struct cache_head *ch = p;
1271 int hash = (*pos >> 32);
1272 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1274 if (p == SEQ_START_TOKEN)
1276 else if (ch->next == NULL) {
1283 *pos &= ~((1LL<<32) - 1);
1284 while (hash < cd->hash_size &&
1285 cd->hash_table[hash] == NULL) {
1289 if (hash >= cd->hash_size)
1292 return cd->hash_table[hash];
1295 static void c_stop(struct seq_file *m, void *p)
1296 __releases(cd->hash_lock)
1298 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1299 read_unlock(&cd->hash_lock);
1302 static int c_show(struct seq_file *m, void *p)
1304 struct cache_head *cp = p;
1305 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1307 if (p == SEQ_START_TOKEN)
1308 return cd->cache_show(m, cd, NULL);
1311 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
1312 convert_to_wallclock(cp->expiry_time),
1313 atomic_read(&cp->ref.refcount), cp->flags);
1315 if (cache_check(cd, cp, NULL))
1316 /* cache_check does a cache_put on failure */
1317 seq_printf(m, "# ");
1321 return cd->cache_show(m, cd, cp);
1324 static const struct seq_operations cache_content_op = {
1331 static int content_open(struct inode *inode, struct file *file,
1332 struct cache_detail *cd)
1336 if (!cd || !try_module_get(cd->owner))
1338 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
1340 module_put(cd->owner);
1348 static int content_release(struct inode *inode, struct file *file,
1349 struct cache_detail *cd)
1351 int ret = seq_release_private(inode, file);
1352 module_put(cd->owner);
1356 static int open_flush(struct inode *inode, struct file *file,
1357 struct cache_detail *cd)
1359 if (!cd || !try_module_get(cd->owner))
1361 return nonseekable_open(inode, file);
1364 static int release_flush(struct inode *inode, struct file *file,
1365 struct cache_detail *cd)
1367 module_put(cd->owner);
1371 static ssize_t read_flush(struct file *file, char __user *buf,
1372 size_t count, loff_t *ppos,
1373 struct cache_detail *cd)
1376 unsigned long p = *ppos;
1379 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time));
1386 if (copy_to_user(buf, (void*)(tbuf+p), len))
1392 static ssize_t write_flush(struct file *file, const char __user *buf,
1393 size_t count, loff_t *ppos,
1394 struct cache_detail *cd)
1399 if (*ppos || count > sizeof(tbuf)-1)
1401 if (copy_from_user(tbuf, buf, count))
1404 simple_strtoul(tbuf, &ep, 0);
1405 if (*ep && *ep != '\n')
1409 cd->flush_time = get_expiry(&bp);
1410 cd->nextcheck = seconds_since_boot();
1417 static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1418 size_t count, loff_t *ppos)
1420 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1422 return cache_read(filp, buf, count, ppos, cd);
1425 static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1426 size_t count, loff_t *ppos)
1428 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1430 return cache_write(filp, buf, count, ppos, cd);
1433 static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1435 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1437 return cache_poll(filp, wait, cd);
1440 static long cache_ioctl_procfs(struct file *filp,
1441 unsigned int cmd, unsigned long arg)
1444 struct inode *inode = filp->f_path.dentry->d_inode;
1445 struct cache_detail *cd = PDE(inode)->data;
1448 ret = cache_ioctl(inode, filp, cmd, arg, cd);
1454 static int cache_open_procfs(struct inode *inode, struct file *filp)
1456 struct cache_detail *cd = PDE(inode)->data;
1458 return cache_open(inode, filp, cd);
1461 static int cache_release_procfs(struct inode *inode, struct file *filp)
1463 struct cache_detail *cd = PDE(inode)->data;
1465 return cache_release(inode, filp, cd);
1468 static const struct file_operations cache_file_operations_procfs = {
1469 .owner = THIS_MODULE,
1470 .llseek = no_llseek,
1471 .read = cache_read_procfs,
1472 .write = cache_write_procfs,
1473 .poll = cache_poll_procfs,
1474 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
1475 .open = cache_open_procfs,
1476 .release = cache_release_procfs,
1479 static int content_open_procfs(struct inode *inode, struct file *filp)
1481 struct cache_detail *cd = PDE(inode)->data;
1483 return content_open(inode, filp, cd);
1486 static int content_release_procfs(struct inode *inode, struct file *filp)
1488 struct cache_detail *cd = PDE(inode)->data;
1490 return content_release(inode, filp, cd);
1493 static const struct file_operations content_file_operations_procfs = {
1494 .open = content_open_procfs,
1496 .llseek = seq_lseek,
1497 .release = content_release_procfs,
1500 static int open_flush_procfs(struct inode *inode, struct file *filp)
1502 struct cache_detail *cd = PDE(inode)->data;
1504 return open_flush(inode, filp, cd);
1507 static int release_flush_procfs(struct inode *inode, struct file *filp)
1509 struct cache_detail *cd = PDE(inode)->data;
1511 return release_flush(inode, filp, cd);
1514 static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1515 size_t count, loff_t *ppos)
1517 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1519 return read_flush(filp, buf, count, ppos, cd);
1522 static ssize_t write_flush_procfs(struct file *filp,
1523 const char __user *buf,
1524 size_t count, loff_t *ppos)
1526 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1528 return write_flush(filp, buf, count, ppos, cd);
1531 static const struct file_operations cache_flush_operations_procfs = {
1532 .open = open_flush_procfs,
1533 .read = read_flush_procfs,
1534 .write = write_flush_procfs,
1535 .release = release_flush_procfs,
1538 static void remove_cache_proc_entries(struct cache_detail *cd)
1540 if (cd->u.procfs.proc_ent == NULL)
1542 if (cd->u.procfs.flush_ent)
1543 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1544 if (cd->u.procfs.channel_ent)
1545 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1546 if (cd->u.procfs.content_ent)
1547 remove_proc_entry("content", cd->u.procfs.proc_ent);
1548 cd->u.procfs.proc_ent = NULL;
1549 remove_proc_entry(cd->name, proc_net_rpc);
1552 #ifdef CONFIG_PROC_FS
1553 static int create_cache_proc_entries(struct cache_detail *cd)
1555 struct proc_dir_entry *p;
1557 cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc);
1558 if (cd->u.procfs.proc_ent == NULL)
1560 cd->u.procfs.channel_ent = NULL;
1561 cd->u.procfs.content_ent = NULL;
1563 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1564 cd->u.procfs.proc_ent,
1565 &cache_flush_operations_procfs, cd);
1566 cd->u.procfs.flush_ent = p;
1570 if (cd->cache_upcall || cd->cache_parse) {
1571 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1572 cd->u.procfs.proc_ent,
1573 &cache_file_operations_procfs, cd);
1574 cd->u.procfs.channel_ent = p;
1578 if (cd->cache_show) {
1579 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
1580 cd->u.procfs.proc_ent,
1581 &content_file_operations_procfs, cd);
1582 cd->u.procfs.content_ent = p;
1588 remove_cache_proc_entries(cd);
1591 #else /* CONFIG_PROC_FS */
1592 static int create_cache_proc_entries(struct cache_detail *cd)
1598 void __init cache_initialize(void)
1600 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean);
1603 int cache_register(struct cache_detail *cd)
1607 sunrpc_init_cache_detail(cd);
1608 ret = create_cache_proc_entries(cd);
1610 sunrpc_destroy_cache_detail(cd);
1613 EXPORT_SYMBOL_GPL(cache_register);
1615 void cache_unregister(struct cache_detail *cd)
1617 remove_cache_proc_entries(cd);
1618 sunrpc_destroy_cache_detail(cd);
1620 EXPORT_SYMBOL_GPL(cache_unregister);
1622 static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1623 size_t count, loff_t *ppos)
1625 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1627 return cache_read(filp, buf, count, ppos, cd);
1630 static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1631 size_t count, loff_t *ppos)
1633 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1635 return cache_write(filp, buf, count, ppos, cd);
1638 static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1640 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1642 return cache_poll(filp, wait, cd);
1645 static long cache_ioctl_pipefs(struct file *filp,
1646 unsigned int cmd, unsigned long arg)
1648 struct inode *inode = filp->f_dentry->d_inode;
1649 struct cache_detail *cd = RPC_I(inode)->private;
1653 ret = cache_ioctl(inode, filp, cmd, arg, cd);
1659 static int cache_open_pipefs(struct inode *inode, struct file *filp)
1661 struct cache_detail *cd = RPC_I(inode)->private;
1663 return cache_open(inode, filp, cd);
1666 static int cache_release_pipefs(struct inode *inode, struct file *filp)
1668 struct cache_detail *cd = RPC_I(inode)->private;
1670 return cache_release(inode, filp, cd);
1673 const struct file_operations cache_file_operations_pipefs = {
1674 .owner = THIS_MODULE,
1675 .llseek = no_llseek,
1676 .read = cache_read_pipefs,
1677 .write = cache_write_pipefs,
1678 .poll = cache_poll_pipefs,
1679 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
1680 .open = cache_open_pipefs,
1681 .release = cache_release_pipefs,
1684 static int content_open_pipefs(struct inode *inode, struct file *filp)
1686 struct cache_detail *cd = RPC_I(inode)->private;
1688 return content_open(inode, filp, cd);
1691 static int content_release_pipefs(struct inode *inode, struct file *filp)
1693 struct cache_detail *cd = RPC_I(inode)->private;
1695 return content_release(inode, filp, cd);
1698 const struct file_operations content_file_operations_pipefs = {
1699 .open = content_open_pipefs,
1701 .llseek = seq_lseek,
1702 .release = content_release_pipefs,
1705 static int open_flush_pipefs(struct inode *inode, struct file *filp)
1707 struct cache_detail *cd = RPC_I(inode)->private;
1709 return open_flush(inode, filp, cd);
1712 static int release_flush_pipefs(struct inode *inode, struct file *filp)
1714 struct cache_detail *cd = RPC_I(inode)->private;
1716 return release_flush(inode, filp, cd);
1719 static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1720 size_t count, loff_t *ppos)
1722 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1724 return read_flush(filp, buf, count, ppos, cd);
1727 static ssize_t write_flush_pipefs(struct file *filp,
1728 const char __user *buf,
1729 size_t count, loff_t *ppos)
1731 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1733 return write_flush(filp, buf, count, ppos, cd);
1736 const struct file_operations cache_flush_operations_pipefs = {
1737 .open = open_flush_pipefs,
1738 .read = read_flush_pipefs,
1739 .write = write_flush_pipefs,
1740 .release = release_flush_pipefs,
1743 int sunrpc_cache_register_pipefs(struct dentry *parent,
1744 const char *name, mode_t umode,
1745 struct cache_detail *cd)
1751 sunrpc_init_cache_detail(cd);
1753 q.len = strlen(name);
1754 q.hash = full_name_hash(q.name, q.len);
1755 dir = rpc_create_cache_dir(parent, &q, umode, cd);
1757 cd->u.pipefs.dir = dir;
1759 sunrpc_destroy_cache_detail(cd);
1764 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1766 void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1768 rpc_remove_cache_dir(cd->u.pipefs.dir);
1769 cd->u.pipefs.dir = NULL;
1770 sunrpc_destroy_cache_detail(cd);
1772 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);