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);
248 EXPORT_SYMBOL(cache_check);
251 * caches need to be periodically cleaned.
252 * For this we maintain a list of cache_detail and
253 * a current pointer into that list and into the table
256 * Each time clean_cache is called it finds the next non-empty entry
257 * in the current table and walks the list in that entry
258 * looking for entries that can be removed.
260 * An entry gets removed if:
261 * - The expiry is before current time
262 * - The last_refresh time is before the flush_time for that cache
264 * later we might drop old entries with non-NEVER expiry if that table
265 * is getting 'full' for some definition of 'full'
267 * The question of "how often to scan a table" is an interesting one
268 * and is answered in part by the use of the "nextcheck" field in the
270 * When a scan of a table begins, the nextcheck field is set to a time
271 * that is well into the future.
272 * While scanning, if an expiry time is found that is earlier than the
273 * current nextcheck time, nextcheck is set to that expiry time.
274 * If the flush_time is ever set to a time earlier than the nextcheck
275 * time, the nextcheck time is then set to that flush_time.
277 * A table is then only scanned if the current time is at least
278 * the nextcheck time.
282 static LIST_HEAD(cache_list);
283 static DEFINE_SPINLOCK(cache_list_lock);
284 static struct cache_detail *current_detail;
285 static int current_index;
287 static const struct file_operations cache_file_operations;
288 static const struct file_operations content_file_operations;
289 static const struct file_operations cache_flush_operations;
291 static void do_cache_clean(struct work_struct *work);
292 static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean);
294 static void remove_cache_proc_entries(struct cache_detail *cd)
296 if (cd->proc_ent == NULL)
299 remove_proc_entry("flush", cd->proc_ent);
301 remove_proc_entry("channel", cd->proc_ent);
303 remove_proc_entry("content", cd->proc_ent);
305 remove_proc_entry(cd->name, proc_net_rpc);
308 #ifdef CONFIG_PROC_FS
309 static int create_cache_proc_entries(struct cache_detail *cd)
311 struct proc_dir_entry *p;
313 cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
314 if (cd->proc_ent == NULL)
316 cd->proc_ent->owner = cd->owner;
317 cd->channel_ent = cd->content_ent = NULL;
319 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
320 cd->proc_ent, &cache_flush_operations, cd);
324 p->owner = cd->owner;
326 if (cd->cache_request || cd->cache_parse) {
327 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
328 cd->proc_ent, &cache_file_operations, cd);
332 p->owner = cd->owner;
334 if (cd->cache_show) {
335 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
336 cd->proc_ent, &content_file_operations, cd);
340 p->owner = cd->owner;
344 remove_cache_proc_entries(cd);
347 #else /* CONFIG_PROC_FS */
348 static int create_cache_proc_entries(struct cache_detail *cd)
354 int cache_register(struct cache_detail *cd)
358 ret = create_cache_proc_entries(cd);
361 rwlock_init(&cd->hash_lock);
362 INIT_LIST_HEAD(&cd->queue);
363 spin_lock(&cache_list_lock);
366 atomic_set(&cd->readers, 0);
369 list_add(&cd->others, &cache_list);
370 spin_unlock(&cache_list_lock);
372 /* start the cleaning process */
373 schedule_delayed_work(&cache_cleaner, 0);
376 EXPORT_SYMBOL(cache_register);
378 void cache_unregister(struct cache_detail *cd)
381 spin_lock(&cache_list_lock);
382 write_lock(&cd->hash_lock);
383 if (cd->entries || atomic_read(&cd->inuse)) {
384 write_unlock(&cd->hash_lock);
385 spin_unlock(&cache_list_lock);
388 if (current_detail == cd)
389 current_detail = NULL;
390 list_del_init(&cd->others);
391 write_unlock(&cd->hash_lock);
392 spin_unlock(&cache_list_lock);
393 remove_cache_proc_entries(cd);
394 if (list_empty(&cache_list)) {
395 /* module must be being unloaded so its safe to kill the worker */
396 cancel_delayed_work_sync(&cache_cleaner);
400 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
402 EXPORT_SYMBOL(cache_unregister);
404 /* clean cache tries to find something to clean
406 * It returns 1 if it cleaned something,
407 * 0 if it didn't find anything this time
408 * -1 if it fell off the end of the list.
410 static int cache_clean(void)
413 struct list_head *next;
415 spin_lock(&cache_list_lock);
417 /* find a suitable table if we don't already have one */
418 while (current_detail == NULL ||
419 current_index >= current_detail->hash_size) {
421 next = current_detail->others.next;
423 next = cache_list.next;
424 if (next == &cache_list) {
425 current_detail = NULL;
426 spin_unlock(&cache_list_lock);
429 current_detail = list_entry(next, struct cache_detail, others);
430 if (current_detail->nextcheck > get_seconds())
431 current_index = current_detail->hash_size;
434 current_detail->nextcheck = get_seconds()+30*60;
438 /* find a non-empty bucket in the table */
439 while (current_detail &&
440 current_index < current_detail->hash_size &&
441 current_detail->hash_table[current_index] == NULL)
444 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
446 if (current_detail && current_index < current_detail->hash_size) {
447 struct cache_head *ch, **cp;
448 struct cache_detail *d;
450 write_lock(¤t_detail->hash_lock);
452 /* Ok, now to clean this strand */
454 cp = & current_detail->hash_table[current_index];
456 for (; ch; cp= & ch->next, ch= *cp) {
457 if (current_detail->nextcheck > ch->expiry_time)
458 current_detail->nextcheck = ch->expiry_time+1;
459 if (ch->expiry_time >= get_seconds()
460 && ch->last_refresh >= current_detail->flush_time
463 if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
464 queue_loose(current_detail, ch);
466 if (atomic_read(&ch->ref.refcount) == 1)
472 current_detail->entries--;
475 write_unlock(¤t_detail->hash_lock);
479 spin_unlock(&cache_list_lock);
483 spin_unlock(&cache_list_lock);
489 * We want to regularly clean the cache, so we need to schedule some work ...
491 static void do_cache_clean(struct work_struct *work)
494 if (cache_clean() == -1)
497 if (list_empty(&cache_list))
501 schedule_delayed_work(&cache_cleaner, delay);
506 * Clean all caches promptly. This just calls cache_clean
507 * repeatedly until we are sure that every cache has had a chance to
510 void cache_flush(void)
512 while (cache_clean() != -1)
514 while (cache_clean() != -1)
517 EXPORT_SYMBOL(cache_flush);
519 void cache_purge(struct cache_detail *detail)
521 detail->flush_time = LONG_MAX;
522 detail->nextcheck = get_seconds();
524 detail->flush_time = 1;
526 EXPORT_SYMBOL(cache_purge);
530 * Deferral and Revisiting of Requests.
532 * If a cache lookup finds a pending entry, we
533 * need to defer the request and revisit it later.
534 * All deferred requests are stored in a hash table,
535 * indexed by "struct cache_head *".
536 * As it may be wasteful to store a whole request
537 * structure, we allow the request to provide a
538 * deferred form, which must contain a
539 * 'struct cache_deferred_req'
540 * This cache_deferred_req contains a method to allow
541 * it to be revisited when cache info is available
544 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
545 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
547 #define DFR_MAX 300 /* ??? */
549 static DEFINE_SPINLOCK(cache_defer_lock);
550 static LIST_HEAD(cache_defer_list);
551 static struct list_head cache_defer_hash[DFR_HASHSIZE];
552 static int cache_defer_cnt;
554 static int cache_defer_req(struct cache_req *req, struct cache_head *item)
556 struct cache_deferred_req *dreq;
557 int hash = DFR_HASH(item);
559 if (cache_defer_cnt >= DFR_MAX) {
560 /* too much in the cache, randomly drop this one,
561 * or continue and drop the oldest below
566 dreq = req->defer(req);
572 spin_lock(&cache_defer_lock);
574 list_add(&dreq->recent, &cache_defer_list);
576 if (cache_defer_hash[hash].next == NULL)
577 INIT_LIST_HEAD(&cache_defer_hash[hash]);
578 list_add(&dreq->hash, &cache_defer_hash[hash]);
580 /* it is in, now maybe clean up */
582 if (++cache_defer_cnt > DFR_MAX) {
583 dreq = list_entry(cache_defer_list.prev,
584 struct cache_deferred_req, recent);
585 list_del(&dreq->recent);
586 list_del(&dreq->hash);
589 spin_unlock(&cache_defer_lock);
592 /* there was one too many */
593 dreq->revisit(dreq, 1);
595 if (!test_bit(CACHE_PENDING, &item->flags)) {
596 /* must have just been validated... */
597 cache_revisit_request(item);
602 static void cache_revisit_request(struct cache_head *item)
604 struct cache_deferred_req *dreq;
605 struct list_head pending;
607 struct list_head *lp;
608 int hash = DFR_HASH(item);
610 INIT_LIST_HEAD(&pending);
611 spin_lock(&cache_defer_lock);
613 lp = cache_defer_hash[hash].next;
615 while (lp != &cache_defer_hash[hash]) {
616 dreq = list_entry(lp, struct cache_deferred_req, hash);
618 if (dreq->item == item) {
619 list_del(&dreq->hash);
620 list_move(&dreq->recent, &pending);
625 spin_unlock(&cache_defer_lock);
627 while (!list_empty(&pending)) {
628 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
629 list_del_init(&dreq->recent);
630 dreq->revisit(dreq, 0);
634 void cache_clean_deferred(void *owner)
636 struct cache_deferred_req *dreq, *tmp;
637 struct list_head pending;
640 INIT_LIST_HEAD(&pending);
641 spin_lock(&cache_defer_lock);
643 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
644 if (dreq->owner == owner) {
645 list_del(&dreq->hash);
646 list_move(&dreq->recent, &pending);
650 spin_unlock(&cache_defer_lock);
652 while (!list_empty(&pending)) {
653 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
654 list_del_init(&dreq->recent);
655 dreq->revisit(dreq, 1);
660 * communicate with user-space
662 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
663 * On read, you get a full request, or block.
664 * On write, an update request is processed.
665 * Poll works if anything to read, and always allows write.
667 * Implemented by linked list of requests. Each open file has
668 * a ->private that also exists in this list. New requests are added
669 * to the end and may wakeup and preceding readers.
670 * New readers are added to the head. If, on read, an item is found with
671 * CACHE_UPCALLING clear, we free it from the list.
675 static DEFINE_SPINLOCK(queue_lock);
676 static DEFINE_MUTEX(queue_io_mutex);
679 struct list_head list;
680 int reader; /* if 0, then request */
682 struct cache_request {
683 struct cache_queue q;
684 struct cache_head *item;
689 struct cache_reader {
690 struct cache_queue q;
691 int offset; /* if non-0, we have a refcnt on next request */
695 cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
697 struct cache_reader *rp = filp->private_data;
698 struct cache_request *rq;
699 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
705 mutex_lock(&queue_io_mutex); /* protect against multiple concurrent
706 * readers on this file */
708 spin_lock(&queue_lock);
709 /* need to find next request */
710 while (rp->q.list.next != &cd->queue &&
711 list_entry(rp->q.list.next, struct cache_queue, list)
713 struct list_head *next = rp->q.list.next;
714 list_move(&rp->q.list, next);
716 if (rp->q.list.next == &cd->queue) {
717 spin_unlock(&queue_lock);
718 mutex_unlock(&queue_io_mutex);
722 rq = container_of(rp->q.list.next, struct cache_request, q.list);
723 BUG_ON(rq->q.reader);
726 spin_unlock(&queue_lock);
728 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
730 spin_lock(&queue_lock);
731 list_move(&rp->q.list, &rq->q.list);
732 spin_unlock(&queue_lock);
734 if (rp->offset + count > rq->len)
735 count = rq->len - rp->offset;
737 if (copy_to_user(buf, rq->buf + rp->offset, count))
740 if (rp->offset >= rq->len) {
742 spin_lock(&queue_lock);
743 list_move(&rp->q.list, &rq->q.list);
744 spin_unlock(&queue_lock);
749 if (rp->offset == 0) {
750 /* need to release rq */
751 spin_lock(&queue_lock);
753 if (rq->readers == 0 &&
754 !test_bit(CACHE_PENDING, &rq->item->flags)) {
755 list_del(&rq->q.list);
756 spin_unlock(&queue_lock);
757 cache_put(rq->item, cd);
761 spin_unlock(&queue_lock);
765 mutex_unlock(&queue_io_mutex);
766 return err ? err : count;
769 static char write_buf[8192]; /* protected by queue_io_mutex */
772 cache_write(struct file *filp, const char __user *buf, size_t count,
776 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
780 if (count >= sizeof(write_buf))
783 mutex_lock(&queue_io_mutex);
785 if (copy_from_user(write_buf, buf, count)) {
786 mutex_unlock(&queue_io_mutex);
789 write_buf[count] = '\0';
791 err = cd->cache_parse(cd, write_buf, count);
795 mutex_unlock(&queue_io_mutex);
796 return err ? err : count;
799 static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
802 cache_poll(struct file *filp, poll_table *wait)
805 struct cache_reader *rp = filp->private_data;
806 struct cache_queue *cq;
807 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
809 poll_wait(filp, &queue_wait, wait);
811 /* alway allow write */
812 mask = POLL_OUT | POLLWRNORM;
817 spin_lock(&queue_lock);
819 for (cq= &rp->q; &cq->list != &cd->queue;
820 cq = list_entry(cq->list.next, struct cache_queue, list))
822 mask |= POLLIN | POLLRDNORM;
825 spin_unlock(&queue_lock);
830 cache_ioctl(struct inode *ino, struct file *filp,
831 unsigned int cmd, unsigned long arg)
834 struct cache_reader *rp = filp->private_data;
835 struct cache_queue *cq;
836 struct cache_detail *cd = PDE(ino)->data;
838 if (cmd != FIONREAD || !rp)
841 spin_lock(&queue_lock);
843 /* only find the length remaining in current request,
844 * or the length of the next request
846 for (cq= &rp->q; &cq->list != &cd->queue;
847 cq = list_entry(cq->list.next, struct cache_queue, list))
849 struct cache_request *cr =
850 container_of(cq, struct cache_request, q);
851 len = cr->len - rp->offset;
854 spin_unlock(&queue_lock);
856 return put_user(len, (int __user *)arg);
860 cache_open(struct inode *inode, struct file *filp)
862 struct cache_reader *rp = NULL;
864 nonseekable_open(inode, filp);
865 if (filp->f_mode & FMODE_READ) {
866 struct cache_detail *cd = PDE(inode)->data;
868 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
873 atomic_inc(&cd->readers);
874 spin_lock(&queue_lock);
875 list_add(&rp->q.list, &cd->queue);
876 spin_unlock(&queue_lock);
878 filp->private_data = rp;
883 cache_release(struct inode *inode, struct file *filp)
885 struct cache_reader *rp = filp->private_data;
886 struct cache_detail *cd = PDE(inode)->data;
889 spin_lock(&queue_lock);
891 struct cache_queue *cq;
892 for (cq= &rp->q; &cq->list != &cd->queue;
893 cq = list_entry(cq->list.next, struct cache_queue, list))
895 container_of(cq, struct cache_request, q)
901 list_del(&rp->q.list);
902 spin_unlock(&queue_lock);
904 filp->private_data = NULL;
907 cd->last_close = get_seconds();
908 atomic_dec(&cd->readers);
915 static const struct file_operations cache_file_operations = {
916 .owner = THIS_MODULE,
919 .write = cache_write,
921 .ioctl = cache_ioctl, /* for FIONREAD */
923 .release = cache_release,
927 static void queue_loose(struct cache_detail *detail, struct cache_head *ch)
929 struct cache_queue *cq;
930 spin_lock(&queue_lock);
931 list_for_each_entry(cq, &detail->queue, list)
933 struct cache_request *cr = container_of(cq, struct cache_request, q);
936 if (cr->readers != 0)
938 list_del(&cr->q.list);
939 spin_unlock(&queue_lock);
940 cache_put(cr->item, detail);
945 spin_unlock(&queue_lock);
949 * Support routines for text-based upcalls.
950 * Fields are separated by spaces.
951 * Fields are either mangled to quote space tab newline slosh with slosh
952 * or a hexified with a leading \x
953 * Record is terminated with newline.
957 void qword_add(char **bpp, int *lp, char *str)
965 while ((c=*str++) && len)
973 *bp++ = '0' + ((c & 0300)>>6);
974 *bp++ = '0' + ((c & 0070)>>3);
975 *bp++ = '0' + ((c & 0007)>>0);
983 if (c || len <1) len = -1;
991 EXPORT_SYMBOL(qword_add);
993 void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1004 while (blen && len >= 2) {
1005 unsigned char c = *buf++;
1006 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
1007 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
1012 if (blen || len<1) len = -1;
1020 EXPORT_SYMBOL(qword_addhex);
1022 static void warn_no_listener(struct cache_detail *detail)
1024 if (detail->last_warn != detail->last_close) {
1025 detail->last_warn = detail->last_close;
1026 if (detail->warn_no_listener)
1027 detail->warn_no_listener(detail);
1032 * register an upcall request to user-space.
1033 * Each request is at most one page long.
1035 static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h)
1039 struct cache_request *crq;
1043 if (detail->cache_request == NULL)
1046 if (atomic_read(&detail->readers) == 0 &&
1047 detail->last_close < get_seconds() - 30) {
1048 warn_no_listener(detail);
1052 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1056 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1062 bp = buf; len = PAGE_SIZE;
1064 detail->cache_request(detail, h, &bp, &len);
1072 crq->item = cache_get(h);
1074 crq->len = PAGE_SIZE - len;
1076 spin_lock(&queue_lock);
1077 list_add_tail(&crq->q.list, &detail->queue);
1078 spin_unlock(&queue_lock);
1079 wake_up(&queue_wait);
1084 * parse a message from user-space and pass it
1085 * to an appropriate cache
1086 * Messages are, like requests, separated into fields by
1087 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1090 * reply cachename expiry key ... content....
1092 * key and content are both parsed by cache
1095 #define isodigit(c) (isdigit(c) && c <= '7')
1096 int qword_get(char **bpp, char *dest, int bufsize)
1098 /* return bytes copied, or -1 on error */
1102 while (*bp == ' ') bp++;
1104 if (bp[0] == '\\' && bp[1] == 'x') {
1107 while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) {
1108 int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
1111 byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
1117 /* text with \nnn octal quoting */
1118 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1120 isodigit(bp[1]) && (bp[1] <= '3') &&
1123 int byte = (*++bp -'0');
1125 byte = (byte << 3) | (*bp++ - '0');
1126 byte = (byte << 3) | (*bp++ - '0');
1136 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1138 while (*bp == ' ') bp++;
1143 EXPORT_SYMBOL(qword_get);
1147 * support /proc/sunrpc/cache/$CACHENAME/content
1149 * We call ->cache_show passing NULL for the item to
1150 * get a header, then pass each real item in the cache
1154 struct cache_detail *cd;
1157 static void *c_start(struct seq_file *m, loff_t *pos)
1158 __acquires(cd->hash_lock)
1161 unsigned hash, entry;
1162 struct cache_head *ch;
1163 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1166 read_lock(&cd->hash_lock);
1168 return SEQ_START_TOKEN;
1170 entry = n & ((1LL<<32) - 1);
1172 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1175 n &= ~((1LL<<32) - 1);
1179 } while(hash < cd->hash_size &&
1180 cd->hash_table[hash]==NULL);
1181 if (hash >= cd->hash_size)
1184 return cd->hash_table[hash];
1187 static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1189 struct cache_head *ch = p;
1190 int hash = (*pos >> 32);
1191 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1193 if (p == SEQ_START_TOKEN)
1195 else if (ch->next == NULL) {
1202 *pos &= ~((1LL<<32) - 1);
1203 while (hash < cd->hash_size &&
1204 cd->hash_table[hash] == NULL) {
1208 if (hash >= cd->hash_size)
1211 return cd->hash_table[hash];
1214 static void c_stop(struct seq_file *m, void *p)
1215 __releases(cd->hash_lock)
1217 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1218 read_unlock(&cd->hash_lock);
1221 static int c_show(struct seq_file *m, void *p)
1223 struct cache_head *cp = p;
1224 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1226 if (p == SEQ_START_TOKEN)
1227 return cd->cache_show(m, cd, NULL);
1230 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
1231 cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags);
1233 if (cache_check(cd, cp, NULL))
1234 /* cache_check does a cache_put on failure */
1235 seq_printf(m, "# ");
1239 return cd->cache_show(m, cd, cp);
1242 static const struct seq_operations cache_content_op = {
1249 static int content_open(struct inode *inode, struct file *file)
1252 struct cache_detail *cd = PDE(inode)->data;
1254 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
1262 static const struct file_operations content_file_operations = {
1263 .open = content_open,
1265 .llseek = seq_lseek,
1266 .release = seq_release_private,
1269 static ssize_t read_flush(struct file *file, char __user *buf,
1270 size_t count, loff_t *ppos)
1272 struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
1274 unsigned long p = *ppos;
1277 sprintf(tbuf, "%lu\n", cd->flush_time);
1284 if (copy_to_user(buf, (void*)(tbuf+p), len))
1290 static ssize_t write_flush(struct file * file, const char __user * buf,
1291 size_t count, loff_t *ppos)
1293 struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
1297 if (*ppos || count > sizeof(tbuf)-1)
1299 if (copy_from_user(tbuf, buf, count))
1302 flushtime = simple_strtoul(tbuf, &ep, 0);
1303 if (*ep && *ep != '\n')
1306 cd->flush_time = flushtime;
1307 cd->nextcheck = get_seconds();
1314 static const struct file_operations cache_flush_operations = {
1315 .open = nonseekable_open,
1317 .write = write_flush,