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 <asm/ioctls.h>
31 #include <linux/sunrpc/types.h>
32 #include <linux/sunrpc/cache.h>
33 #include <linux/sunrpc/stats.h>
35 #define RPCDBG_FACILITY RPCDBG_CACHE
37 static int cache_defer_req(struct cache_req *req, struct cache_head *item);
38 static void cache_revisit_request(struct cache_head *item);
40 static void cache_init(struct cache_head *h)
42 time_t now = get_seconds();
46 h->expiry_time = now + CACHE_NEW_EXPIRY;
47 h->last_refresh = now;
50 struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
51 struct cache_head *key, int hash)
53 struct cache_head **head, **hp;
54 struct cache_head *new = NULL;
56 head = &detail->hash_table[hash];
58 read_lock(&detail->hash_lock);
60 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
61 struct cache_head *tmp = *hp;
62 if (detail->match(tmp, key)) {
64 read_unlock(&detail->hash_lock);
68 read_unlock(&detail->hash_lock);
69 /* Didn't find anything, insert an empty entry */
71 new = detail->alloc();
74 /* must fully initialise 'new', else
75 * we might get lose if we need to
79 detail->init(new, key);
81 write_lock(&detail->hash_lock);
83 /* check if entry appeared while we slept */
84 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
85 struct cache_head *tmp = *hp;
86 if (detail->match(tmp, key)) {
88 write_unlock(&detail->hash_lock);
89 cache_put(new, detail);
97 write_unlock(&detail->hash_lock);
101 EXPORT_SYMBOL(sunrpc_cache_lookup);
104 static void queue_loose(struct cache_detail *detail, struct cache_head *ch);
106 static int cache_fresh_locked(struct cache_head *head, time_t expiry)
108 head->expiry_time = expiry;
109 head->last_refresh = get_seconds();
110 return !test_and_set_bit(CACHE_VALID, &head->flags);
113 static void cache_fresh_unlocked(struct cache_head *head,
114 struct cache_detail *detail, int new)
117 cache_revisit_request(head);
118 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
119 cache_revisit_request(head);
120 queue_loose(detail, head);
124 struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
125 struct cache_head *new, struct cache_head *old, int hash)
127 /* The 'old' entry is to be replaced by 'new'.
128 * If 'old' is not VALID, we update it directly,
129 * otherwise we need to replace it
131 struct cache_head **head;
132 struct cache_head *tmp;
135 if (!test_bit(CACHE_VALID, &old->flags)) {
136 write_lock(&detail->hash_lock);
137 if (!test_bit(CACHE_VALID, &old->flags)) {
138 if (test_bit(CACHE_NEGATIVE, &new->flags))
139 set_bit(CACHE_NEGATIVE, &old->flags);
141 detail->update(old, new);
142 is_new = cache_fresh_locked(old, new->expiry_time);
143 write_unlock(&detail->hash_lock);
144 cache_fresh_unlocked(old, detail, is_new);
147 write_unlock(&detail->hash_lock);
149 /* We need to insert a new entry */
150 tmp = detail->alloc();
152 cache_put(old, detail);
156 detail->init(tmp, old);
157 head = &detail->hash_table[hash];
159 write_lock(&detail->hash_lock);
160 if (test_bit(CACHE_NEGATIVE, &new->flags))
161 set_bit(CACHE_NEGATIVE, &tmp->flags);
163 detail->update(tmp, new);
168 is_new = cache_fresh_locked(tmp, new->expiry_time);
169 cache_fresh_locked(old, 0);
170 write_unlock(&detail->hash_lock);
171 cache_fresh_unlocked(tmp, detail, is_new);
172 cache_fresh_unlocked(old, detail, 0);
173 cache_put(old, detail);
176 EXPORT_SYMBOL(sunrpc_cache_update);
178 static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h);
180 * This is the generic cache management routine for all
181 * the authentication caches.
182 * It checks the currency of a cache item and will (later)
183 * initiate an upcall to fill it if needed.
186 * Returns 0 if the cache_head can be used, or cache_puts it and returns
187 * -EAGAIN if upcall is pending,
188 * -ETIMEDOUT if upcall failed and should be retried,
189 * -ENOENT if cache entry was negative
191 int cache_check(struct cache_detail *detail,
192 struct cache_head *h, struct cache_req *rqstp)
195 long refresh_age, age;
197 /* First decide return status as best we can */
198 if (!test_bit(CACHE_VALID, &h->flags) ||
199 h->expiry_time < get_seconds())
201 else if (detail->flush_time > h->last_refresh)
205 if (test_bit(CACHE_NEGATIVE, &h->flags))
210 /* now see if we want to start an upcall */
211 refresh_age = (h->expiry_time - h->last_refresh);
212 age = get_seconds() - h->last_refresh;
217 } else if (rv == -EAGAIN || age > refresh_age/2) {
218 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
220 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
221 switch (cache_make_upcall(detail, h)) {
223 clear_bit(CACHE_PENDING, &h->flags);
225 set_bit(CACHE_NEGATIVE, &h->flags);
226 cache_fresh_unlocked(h, detail,
227 cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY));
233 clear_bit(CACHE_PENDING, &h->flags);
234 cache_revisit_request(h);
241 if (cache_defer_req(rqstp, h) != 0)
245 cache_put(h, detail);
250 * caches need to be periodically cleaned.
251 * For this we maintain a list of cache_detail and
252 * a current pointer into that list and into the table
255 * Each time clean_cache is called it finds the next non-empty entry
256 * in the current table and walks the list in that entry
257 * looking for entries that can be removed.
259 * An entry gets removed if:
260 * - The expiry is before current time
261 * - The last_refresh time is before the flush_time for that cache
263 * later we might drop old entries with non-NEVER expiry if that table
264 * is getting 'full' for some definition of 'full'
266 * The question of "how often to scan a table" is an interesting one
267 * and is answered in part by the use of the "nextcheck" field in the
269 * When a scan of a table begins, the nextcheck field is set to a time
270 * that is well into the future.
271 * While scanning, if an expiry time is found that is earlier than the
272 * current nextcheck time, nextcheck is set to that expiry time.
273 * If the flush_time is ever set to a time earlier than the nextcheck
274 * time, the nextcheck time is then set to that flush_time.
276 * A table is then only scanned if the current time is at least
277 * the nextcheck time.
281 static LIST_HEAD(cache_list);
282 static DEFINE_SPINLOCK(cache_list_lock);
283 static struct cache_detail *current_detail;
284 static int current_index;
286 static const struct file_operations cache_file_operations;
287 static const struct file_operations content_file_operations;
288 static const struct file_operations cache_flush_operations;
290 static void do_cache_clean(struct work_struct *work);
291 static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean);
293 static void remove_cache_proc_entries(struct cache_detail *cd)
295 if (cd->proc_ent == NULL)
298 remove_proc_entry("flush", cd->proc_ent);
300 remove_proc_entry("channel", cd->proc_ent);
302 remove_proc_entry("content", cd->proc_ent);
304 remove_proc_entry(cd->name, proc_net_rpc);
307 static void create_cache_proc_entries(struct cache_detail *cd)
309 struct proc_dir_entry *p;
311 cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
312 if (cd->proc_ent == NULL)
314 cd->proc_ent->owner = cd->owner;
315 cd->channel_ent = cd->content_ent = NULL;
317 p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR, cd->proc_ent);
321 p->proc_fops = &cache_flush_operations;
322 p->owner = cd->owner;
325 if (cd->cache_request || cd->cache_parse) {
326 p = create_proc_entry("channel", S_IFREG|S_IRUSR|S_IWUSR,
331 p->proc_fops = &cache_file_operations;
332 p->owner = cd->owner;
335 if (cd->cache_show) {
336 p = create_proc_entry("content", S_IFREG|S_IRUSR|S_IWUSR,
341 p->proc_fops = &content_file_operations;
342 p->owner = cd->owner;
347 void cache_register(struct cache_detail *cd)
349 create_cache_proc_entries(cd);
350 rwlock_init(&cd->hash_lock);
351 INIT_LIST_HEAD(&cd->queue);
352 spin_lock(&cache_list_lock);
355 atomic_set(&cd->readers, 0);
358 list_add(&cd->others, &cache_list);
359 spin_unlock(&cache_list_lock);
361 /* start the cleaning process */
362 schedule_delayed_work(&cache_cleaner, 0);
365 void cache_unregister(struct cache_detail *cd)
368 spin_lock(&cache_list_lock);
369 write_lock(&cd->hash_lock);
370 if (cd->entries || atomic_read(&cd->inuse)) {
371 write_unlock(&cd->hash_lock);
372 spin_unlock(&cache_list_lock);
375 if (current_detail == cd)
376 current_detail = NULL;
377 list_del_init(&cd->others);
378 write_unlock(&cd->hash_lock);
379 spin_unlock(&cache_list_lock);
380 remove_cache_proc_entries(cd);
381 if (list_empty(&cache_list)) {
382 /* module must be being unloaded so its safe to kill the worker */
383 cancel_delayed_work_sync(&cache_cleaner);
387 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
390 /* clean cache tries to find something to clean
392 * It returns 1 if it cleaned something,
393 * 0 if it didn't find anything this time
394 * -1 if it fell off the end of the list.
396 static int cache_clean(void)
399 struct list_head *next;
401 spin_lock(&cache_list_lock);
403 /* find a suitable table if we don't already have one */
404 while (current_detail == NULL ||
405 current_index >= current_detail->hash_size) {
407 next = current_detail->others.next;
409 next = cache_list.next;
410 if (next == &cache_list) {
411 current_detail = NULL;
412 spin_unlock(&cache_list_lock);
415 current_detail = list_entry(next, struct cache_detail, others);
416 if (current_detail->nextcheck > get_seconds())
417 current_index = current_detail->hash_size;
420 current_detail->nextcheck = get_seconds()+30*60;
424 /* find a non-empty bucket in the table */
425 while (current_detail &&
426 current_index < current_detail->hash_size &&
427 current_detail->hash_table[current_index] == NULL)
430 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
432 if (current_detail && current_index < current_detail->hash_size) {
433 struct cache_head *ch, **cp;
434 struct cache_detail *d;
436 write_lock(¤t_detail->hash_lock);
438 /* Ok, now to clean this strand */
440 cp = & current_detail->hash_table[current_index];
442 for (; ch; cp= & ch->next, ch= *cp) {
443 if (current_detail->nextcheck > ch->expiry_time)
444 current_detail->nextcheck = ch->expiry_time+1;
445 if (ch->expiry_time >= get_seconds()
446 && ch->last_refresh >= current_detail->flush_time
449 if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
450 queue_loose(current_detail, ch);
452 if (atomic_read(&ch->ref.refcount) == 1)
458 current_detail->entries--;
461 write_unlock(¤t_detail->hash_lock);
465 spin_unlock(&cache_list_lock);
469 spin_unlock(&cache_list_lock);
475 * We want to regularly clean the cache, so we need to schedule some work ...
477 static void do_cache_clean(struct work_struct *work)
480 if (cache_clean() == -1)
483 if (list_empty(&cache_list))
487 schedule_delayed_work(&cache_cleaner, delay);
492 * Clean all caches promptly. This just calls cache_clean
493 * repeatedly until we are sure that every cache has had a chance to
496 void cache_flush(void)
498 while (cache_clean() != -1)
500 while (cache_clean() != -1)
504 void cache_purge(struct cache_detail *detail)
506 detail->flush_time = LONG_MAX;
507 detail->nextcheck = get_seconds();
509 detail->flush_time = 1;
515 * Deferral and Revisiting of Requests.
517 * If a cache lookup finds a pending entry, we
518 * need to defer the request and revisit it later.
519 * All deferred requests are stored in a hash table,
520 * indexed by "struct cache_head *".
521 * As it may be wasteful to store a whole request
522 * structure, we allow the request to provide a
523 * deferred form, which must contain a
524 * 'struct cache_deferred_req'
525 * This cache_deferred_req contains a method to allow
526 * it to be revisited when cache info is available
529 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
530 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
532 #define DFR_MAX 300 /* ??? */
534 static DEFINE_SPINLOCK(cache_defer_lock);
535 static LIST_HEAD(cache_defer_list);
536 static struct list_head cache_defer_hash[DFR_HASHSIZE];
537 static int cache_defer_cnt;
539 static int cache_defer_req(struct cache_req *req, struct cache_head *item)
541 struct cache_deferred_req *dreq;
542 int hash = DFR_HASH(item);
544 if (cache_defer_cnt >= DFR_MAX) {
545 /* too much in the cache, randomly drop this one,
546 * or continue and drop the oldest below
551 dreq = req->defer(req);
556 dreq->recv_time = get_seconds();
558 spin_lock(&cache_defer_lock);
560 list_add(&dreq->recent, &cache_defer_list);
562 if (cache_defer_hash[hash].next == NULL)
563 INIT_LIST_HEAD(&cache_defer_hash[hash]);
564 list_add(&dreq->hash, &cache_defer_hash[hash]);
566 /* it is in, now maybe clean up */
568 if (++cache_defer_cnt > DFR_MAX) {
569 dreq = list_entry(cache_defer_list.prev,
570 struct cache_deferred_req, recent);
571 list_del(&dreq->recent);
572 list_del(&dreq->hash);
575 spin_unlock(&cache_defer_lock);
578 /* there was one too many */
579 dreq->revisit(dreq, 1);
581 if (!test_bit(CACHE_PENDING, &item->flags)) {
582 /* must have just been validated... */
583 cache_revisit_request(item);
588 static void cache_revisit_request(struct cache_head *item)
590 struct cache_deferred_req *dreq;
591 struct list_head pending;
593 struct list_head *lp;
594 int hash = DFR_HASH(item);
596 INIT_LIST_HEAD(&pending);
597 spin_lock(&cache_defer_lock);
599 lp = cache_defer_hash[hash].next;
601 while (lp != &cache_defer_hash[hash]) {
602 dreq = list_entry(lp, struct cache_deferred_req, hash);
604 if (dreq->item == item) {
605 list_del(&dreq->hash);
606 list_move(&dreq->recent, &pending);
611 spin_unlock(&cache_defer_lock);
613 while (!list_empty(&pending)) {
614 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
615 list_del_init(&dreq->recent);
616 dreq->revisit(dreq, 0);
620 void cache_clean_deferred(void *owner)
622 struct cache_deferred_req *dreq, *tmp;
623 struct list_head pending;
626 INIT_LIST_HEAD(&pending);
627 spin_lock(&cache_defer_lock);
629 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
630 if (dreq->owner == owner) {
631 list_del(&dreq->hash);
632 list_move(&dreq->recent, &pending);
636 spin_unlock(&cache_defer_lock);
638 while (!list_empty(&pending)) {
639 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
640 list_del_init(&dreq->recent);
641 dreq->revisit(dreq, 1);
646 * communicate with user-space
648 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
649 * On read, you get a full request, or block.
650 * On write, an update request is processed.
651 * Poll works if anything to read, and always allows write.
653 * Implemented by linked list of requests. Each open file has
654 * a ->private that also exists in this list. New requests are added
655 * to the end and may wakeup and preceding readers.
656 * New readers are added to the head. If, on read, an item is found with
657 * CACHE_UPCALLING clear, we free it from the list.
661 static DEFINE_SPINLOCK(queue_lock);
662 static DEFINE_MUTEX(queue_io_mutex);
665 struct list_head list;
666 int reader; /* if 0, then request */
668 struct cache_request {
669 struct cache_queue q;
670 struct cache_head *item;
675 struct cache_reader {
676 struct cache_queue q;
677 int offset; /* if non-0, we have a refcnt on next request */
681 cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
683 struct cache_reader *rp = filp->private_data;
684 struct cache_request *rq;
685 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
691 mutex_lock(&queue_io_mutex); /* protect against multiple concurrent
692 * readers on this file */
694 spin_lock(&queue_lock);
695 /* need to find next request */
696 while (rp->q.list.next != &cd->queue &&
697 list_entry(rp->q.list.next, struct cache_queue, list)
699 struct list_head *next = rp->q.list.next;
700 list_move(&rp->q.list, next);
702 if (rp->q.list.next == &cd->queue) {
703 spin_unlock(&queue_lock);
704 mutex_unlock(&queue_io_mutex);
708 rq = container_of(rp->q.list.next, struct cache_request, q.list);
709 BUG_ON(rq->q.reader);
712 spin_unlock(&queue_lock);
714 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
716 spin_lock(&queue_lock);
717 list_move(&rp->q.list, &rq->q.list);
718 spin_unlock(&queue_lock);
720 if (rp->offset + count > rq->len)
721 count = rq->len - rp->offset;
723 if (copy_to_user(buf, rq->buf + rp->offset, count))
726 if (rp->offset >= rq->len) {
728 spin_lock(&queue_lock);
729 list_move(&rp->q.list, &rq->q.list);
730 spin_unlock(&queue_lock);
735 if (rp->offset == 0) {
736 /* need to release rq */
737 spin_lock(&queue_lock);
739 if (rq->readers == 0 &&
740 !test_bit(CACHE_PENDING, &rq->item->flags)) {
741 list_del(&rq->q.list);
742 spin_unlock(&queue_lock);
743 cache_put(rq->item, cd);
747 spin_unlock(&queue_lock);
751 mutex_unlock(&queue_io_mutex);
752 return err ? err : count;
755 static char write_buf[8192]; /* protected by queue_io_mutex */
758 cache_write(struct file *filp, const char __user *buf, size_t count,
762 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
766 if (count >= sizeof(write_buf))
769 mutex_lock(&queue_io_mutex);
771 if (copy_from_user(write_buf, buf, count)) {
772 mutex_unlock(&queue_io_mutex);
775 write_buf[count] = '\0';
777 err = cd->cache_parse(cd, write_buf, count);
781 mutex_unlock(&queue_io_mutex);
782 return err ? err : count;
785 static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
788 cache_poll(struct file *filp, poll_table *wait)
791 struct cache_reader *rp = filp->private_data;
792 struct cache_queue *cq;
793 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
795 poll_wait(filp, &queue_wait, wait);
797 /* alway allow write */
798 mask = POLL_OUT | POLLWRNORM;
803 spin_lock(&queue_lock);
805 for (cq= &rp->q; &cq->list != &cd->queue;
806 cq = list_entry(cq->list.next, struct cache_queue, list))
808 mask |= POLLIN | POLLRDNORM;
811 spin_unlock(&queue_lock);
816 cache_ioctl(struct inode *ino, struct file *filp,
817 unsigned int cmd, unsigned long arg)
820 struct cache_reader *rp = filp->private_data;
821 struct cache_queue *cq;
822 struct cache_detail *cd = PDE(ino)->data;
824 if (cmd != FIONREAD || !rp)
827 spin_lock(&queue_lock);
829 /* only find the length remaining in current request,
830 * or the length of the next request
832 for (cq= &rp->q; &cq->list != &cd->queue;
833 cq = list_entry(cq->list.next, struct cache_queue, list))
835 struct cache_request *cr =
836 container_of(cq, struct cache_request, q);
837 len = cr->len - rp->offset;
840 spin_unlock(&queue_lock);
842 return put_user(len, (int __user *)arg);
846 cache_open(struct inode *inode, struct file *filp)
848 struct cache_reader *rp = NULL;
850 nonseekable_open(inode, filp);
851 if (filp->f_mode & FMODE_READ) {
852 struct cache_detail *cd = PDE(inode)->data;
854 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
859 atomic_inc(&cd->readers);
860 spin_lock(&queue_lock);
861 list_add(&rp->q.list, &cd->queue);
862 spin_unlock(&queue_lock);
864 filp->private_data = rp;
869 cache_release(struct inode *inode, struct file *filp)
871 struct cache_reader *rp = filp->private_data;
872 struct cache_detail *cd = PDE(inode)->data;
875 spin_lock(&queue_lock);
877 struct cache_queue *cq;
878 for (cq= &rp->q; &cq->list != &cd->queue;
879 cq = list_entry(cq->list.next, struct cache_queue, list))
881 container_of(cq, struct cache_request, q)
887 list_del(&rp->q.list);
888 spin_unlock(&queue_lock);
890 filp->private_data = NULL;
893 cd->last_close = get_seconds();
894 atomic_dec(&cd->readers);
901 static const struct file_operations cache_file_operations = {
902 .owner = THIS_MODULE,
905 .write = cache_write,
907 .ioctl = cache_ioctl, /* for FIONREAD */
909 .release = cache_release,
913 static void queue_loose(struct cache_detail *detail, struct cache_head *ch)
915 struct cache_queue *cq;
916 spin_lock(&queue_lock);
917 list_for_each_entry(cq, &detail->queue, list)
919 struct cache_request *cr = container_of(cq, struct cache_request, q);
922 if (cr->readers != 0)
924 list_del(&cr->q.list);
925 spin_unlock(&queue_lock);
926 cache_put(cr->item, detail);
931 spin_unlock(&queue_lock);
935 * Support routines for text-based upcalls.
936 * Fields are separated by spaces.
937 * Fields are either mangled to quote space tab newline slosh with slosh
938 * or a hexified with a leading \x
939 * Record is terminated with newline.
943 void qword_add(char **bpp, int *lp, char *str)
951 while ((c=*str++) && len)
959 *bp++ = '0' + ((c & 0300)>>6);
960 *bp++ = '0' + ((c & 0070)>>3);
961 *bp++ = '0' + ((c & 0007)>>0);
969 if (c || len <1) len = -1;
978 void qword_addhex(char **bpp, int *lp, char *buf, int blen)
989 while (blen && len >= 2) {
990 unsigned char c = *buf++;
991 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
992 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
997 if (blen || len<1) len = -1;
1006 static void warn_no_listener(struct cache_detail *detail)
1008 if (detail->last_warn != detail->last_close) {
1009 detail->last_warn = detail->last_close;
1010 if (detail->warn_no_listener)
1011 detail->warn_no_listener(detail);
1016 * register an upcall request to user-space.
1017 * Each request is at most one page long.
1019 static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h)
1023 struct cache_request *crq;
1027 if (detail->cache_request == NULL)
1030 if (atomic_read(&detail->readers) == 0 &&
1031 detail->last_close < get_seconds() - 30) {
1032 warn_no_listener(detail);
1036 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1040 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1046 bp = buf; len = PAGE_SIZE;
1048 detail->cache_request(detail, h, &bp, &len);
1056 crq->item = cache_get(h);
1058 crq->len = PAGE_SIZE - len;
1060 spin_lock(&queue_lock);
1061 list_add_tail(&crq->q.list, &detail->queue);
1062 spin_unlock(&queue_lock);
1063 wake_up(&queue_wait);
1068 * parse a message from user-space and pass it
1069 * to an appropriate cache
1070 * Messages are, like requests, separated into fields by
1071 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1074 * reply cachename expiry key ... content....
1076 * key and content are both parsed by cache
1079 #define isodigit(c) (isdigit(c) && c <= '7')
1080 int qword_get(char **bpp, char *dest, int bufsize)
1082 /* return bytes copied, or -1 on error */
1086 while (*bp == ' ') bp++;
1088 if (bp[0] == '\\' && bp[1] == 'x') {
1091 while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) {
1092 int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
1095 byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
1101 /* text with \nnn octal quoting */
1102 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1104 isodigit(bp[1]) && (bp[1] <= '3') &&
1107 int byte = (*++bp -'0');
1109 byte = (byte << 3) | (*bp++ - '0');
1110 byte = (byte << 3) | (*bp++ - '0');
1120 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1122 while (*bp == ' ') bp++;
1130 * support /proc/sunrpc/cache/$CACHENAME/content
1132 * We call ->cache_show passing NULL for the item to
1133 * get a header, then pass each real item in the cache
1137 struct cache_detail *cd;
1140 static void *c_start(struct seq_file *m, loff_t *pos)
1141 __acquires(cd->hash_lock)
1144 unsigned hash, entry;
1145 struct cache_head *ch;
1146 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1149 read_lock(&cd->hash_lock);
1151 return SEQ_START_TOKEN;
1153 entry = n & ((1LL<<32) - 1);
1155 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1158 n &= ~((1LL<<32) - 1);
1162 } while(hash < cd->hash_size &&
1163 cd->hash_table[hash]==NULL);
1164 if (hash >= cd->hash_size)
1167 return cd->hash_table[hash];
1170 static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1172 struct cache_head *ch = p;
1173 int hash = (*pos >> 32);
1174 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1176 if (p == SEQ_START_TOKEN)
1178 else if (ch->next == NULL) {
1185 *pos &= ~((1LL<<32) - 1);
1186 while (hash < cd->hash_size &&
1187 cd->hash_table[hash] == NULL) {
1191 if (hash >= cd->hash_size)
1194 return cd->hash_table[hash];
1197 static void c_stop(struct seq_file *m, void *p)
1198 __releases(cd->hash_lock)
1200 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1201 read_unlock(&cd->hash_lock);
1204 static int c_show(struct seq_file *m, void *p)
1206 struct cache_head *cp = p;
1207 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1209 if (p == SEQ_START_TOKEN)
1210 return cd->cache_show(m, cd, NULL);
1213 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
1214 cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags);
1216 if (cache_check(cd, cp, NULL))
1217 /* cache_check does a cache_put on failure */
1218 seq_printf(m, "# ");
1222 return cd->cache_show(m, cd, cp);
1225 static const struct seq_operations cache_content_op = {
1232 static int content_open(struct inode *inode, struct file *file)
1235 struct cache_detail *cd = PDE(inode)->data;
1237 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
1245 static const struct file_operations content_file_operations = {
1246 .open = content_open,
1248 .llseek = seq_lseek,
1249 .release = seq_release_private,
1252 static ssize_t read_flush(struct file *file, char __user *buf,
1253 size_t count, loff_t *ppos)
1255 struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
1257 unsigned long p = *ppos;
1260 sprintf(tbuf, "%lu\n", cd->flush_time);
1267 if (copy_to_user(buf, (void*)(tbuf+p), len))
1273 static ssize_t write_flush(struct file * file, const char __user * buf,
1274 size_t count, loff_t *ppos)
1276 struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
1280 if (*ppos || count > sizeof(tbuf)-1)
1282 if (copy_from_user(tbuf, buf, count))
1285 flushtime = simple_strtoul(tbuf, &ep, 0);
1286 if (*ep && *ep != '\n')
1289 cd->flush_time = flushtime;
1290 cd->nextcheck = get_seconds();
1297 static const struct file_operations cache_flush_operations = {
1298 .open = nonseekable_open,
1300 .write = write_flush,