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 <asm/ioctls.h>
32 #include <linux/sunrpc/types.h>
33 #include <linux/sunrpc/cache.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/rpc_pipe_fs.h>
37 #define RPCDBG_FACILITY RPCDBG_CACHE
39 static int cache_defer_req(struct cache_req *req, struct cache_head *item);
40 static void cache_revisit_request(struct cache_head *item);
42 static void cache_init(struct cache_head *h)
44 time_t now = get_seconds();
48 h->expiry_time = now + CACHE_NEW_EXPIRY;
49 h->last_refresh = now;
52 struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
53 struct cache_head *key, int hash)
55 struct cache_head **head, **hp;
56 struct cache_head *new = NULL;
58 head = &detail->hash_table[hash];
60 read_lock(&detail->hash_lock);
62 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
63 struct cache_head *tmp = *hp;
64 if (detail->match(tmp, key)) {
66 read_unlock(&detail->hash_lock);
70 read_unlock(&detail->hash_lock);
71 /* Didn't find anything, insert an empty entry */
73 new = detail->alloc();
76 /* must fully initialise 'new', else
77 * we might get lose if we need to
81 detail->init(new, key);
83 write_lock(&detail->hash_lock);
85 /* check if entry appeared while we slept */
86 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
87 struct cache_head *tmp = *hp;
88 if (detail->match(tmp, key)) {
90 write_unlock(&detail->hash_lock);
91 cache_put(new, detail);
99 write_unlock(&detail->hash_lock);
103 EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
106 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
108 static int cache_fresh_locked(struct cache_head *head, time_t expiry)
110 head->expiry_time = expiry;
111 head->last_refresh = get_seconds();
112 return !test_and_set_bit(CACHE_VALID, &head->flags);
115 static void cache_fresh_unlocked(struct cache_head *head,
116 struct cache_detail *detail, int new)
119 cache_revisit_request(head);
120 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
121 cache_revisit_request(head);
122 cache_dequeue(detail, head);
126 struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
127 struct cache_head *new, struct cache_head *old, int hash)
129 /* The 'old' entry is to be replaced by 'new'.
130 * If 'old' is not VALID, we update it directly,
131 * otherwise we need to replace it
133 struct cache_head **head;
134 struct cache_head *tmp;
137 if (!test_bit(CACHE_VALID, &old->flags)) {
138 write_lock(&detail->hash_lock);
139 if (!test_bit(CACHE_VALID, &old->flags)) {
140 if (test_bit(CACHE_NEGATIVE, &new->flags))
141 set_bit(CACHE_NEGATIVE, &old->flags);
143 detail->update(old, new);
144 is_new = cache_fresh_locked(old, new->expiry_time);
145 write_unlock(&detail->hash_lock);
146 cache_fresh_unlocked(old, detail, is_new);
149 write_unlock(&detail->hash_lock);
151 /* We need to insert a new entry */
152 tmp = detail->alloc();
154 cache_put(old, detail);
158 detail->init(tmp, old);
159 head = &detail->hash_table[hash];
161 write_lock(&detail->hash_lock);
162 if (test_bit(CACHE_NEGATIVE, &new->flags))
163 set_bit(CACHE_NEGATIVE, &tmp->flags);
165 detail->update(tmp, new);
170 is_new = cache_fresh_locked(tmp, new->expiry_time);
171 cache_fresh_locked(old, 0);
172 write_unlock(&detail->hash_lock);
173 cache_fresh_unlocked(tmp, detail, is_new);
174 cache_fresh_unlocked(old, detail, 0);
175 cache_put(old, detail);
178 EXPORT_SYMBOL_GPL(sunrpc_cache_update);
180 static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
182 if (!cd->cache_upcall)
184 return cd->cache_upcall(cd, h);
187 static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h)
189 if (!test_bit(CACHE_VALID, &h->flags) ||
190 h->expiry_time < get_seconds())
192 else if (detail->flush_time > h->last_refresh)
196 if (test_bit(CACHE_NEGATIVE, &h->flags))
204 * This is the generic cache management routine for all
205 * the authentication caches.
206 * It checks the currency of a cache item and will (later)
207 * initiate an upcall to fill it if needed.
210 * Returns 0 if the cache_head can be used, or cache_puts it and returns
211 * -EAGAIN if upcall is pending and request has been queued
212 * -ETIMEDOUT if upcall failed or request could not be queue or
213 * upcall completed but item is still invalid (implying that
214 * the cache item has been replaced with a newer one).
215 * -ENOENT if cache entry was negative
217 int cache_check(struct cache_detail *detail,
218 struct cache_head *h, struct cache_req *rqstp)
221 long refresh_age, age;
223 /* First decide return status as best we can */
224 rv = cache_is_valid(detail, h);
226 /* now see if we want to start an upcall */
227 refresh_age = (h->expiry_time - h->last_refresh);
228 age = get_seconds() - h->last_refresh;
233 } else if (rv == -EAGAIN || age > refresh_age/2) {
234 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
236 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
237 switch (cache_make_upcall(detail, h)) {
239 clear_bit(CACHE_PENDING, &h->flags);
240 cache_revisit_request(h);
242 set_bit(CACHE_NEGATIVE, &h->flags);
243 cache_fresh_unlocked(h, detail,
244 cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY));
250 clear_bit(CACHE_PENDING, &h->flags);
251 cache_revisit_request(h);
258 if (cache_defer_req(rqstp, h) == 0) {
259 /* Request is not deferred */
260 rv = cache_is_valid(detail, h);
266 cache_put(h, detail);
269 EXPORT_SYMBOL_GPL(cache_check);
272 * caches need to be periodically cleaned.
273 * For this we maintain a list of cache_detail and
274 * a current pointer into that list and into the table
277 * Each time clean_cache is called it finds the next non-empty entry
278 * in the current table and walks the list in that entry
279 * looking for entries that can be removed.
281 * An entry gets removed if:
282 * - The expiry is before current time
283 * - The last_refresh time is before the flush_time for that cache
285 * later we might drop old entries with non-NEVER expiry if that table
286 * is getting 'full' for some definition of 'full'
288 * The question of "how often to scan a table" is an interesting one
289 * and is answered in part by the use of the "nextcheck" field in the
291 * When a scan of a table begins, the nextcheck field is set to a time
292 * that is well into the future.
293 * While scanning, if an expiry time is found that is earlier than the
294 * current nextcheck time, nextcheck is set to that expiry time.
295 * If the flush_time is ever set to a time earlier than the nextcheck
296 * time, the nextcheck time is then set to that flush_time.
298 * A table is then only scanned if the current time is at least
299 * the nextcheck time.
303 static LIST_HEAD(cache_list);
304 static DEFINE_SPINLOCK(cache_list_lock);
305 static struct cache_detail *current_detail;
306 static int current_index;
308 static void do_cache_clean(struct work_struct *work);
309 static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean);
311 static void sunrpc_init_cache_detail(struct cache_detail *cd)
313 rwlock_init(&cd->hash_lock);
314 INIT_LIST_HEAD(&cd->queue);
315 spin_lock(&cache_list_lock);
318 atomic_set(&cd->readers, 0);
321 list_add(&cd->others, &cache_list);
322 spin_unlock(&cache_list_lock);
324 /* start the cleaning process */
325 schedule_delayed_work(&cache_cleaner, 0);
328 static void sunrpc_destroy_cache_detail(struct cache_detail *cd)
331 spin_lock(&cache_list_lock);
332 write_lock(&cd->hash_lock);
333 if (cd->entries || atomic_read(&cd->inuse)) {
334 write_unlock(&cd->hash_lock);
335 spin_unlock(&cache_list_lock);
338 if (current_detail == cd)
339 current_detail = NULL;
340 list_del_init(&cd->others);
341 write_unlock(&cd->hash_lock);
342 spin_unlock(&cache_list_lock);
343 if (list_empty(&cache_list)) {
344 /* module must be being unloaded so its safe to kill the worker */
345 cancel_delayed_work_sync(&cache_cleaner);
349 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
352 /* clean cache tries to find something to clean
354 * It returns 1 if it cleaned something,
355 * 0 if it didn't find anything this time
356 * -1 if it fell off the end of the list.
358 static int cache_clean(void)
361 struct list_head *next;
363 spin_lock(&cache_list_lock);
365 /* find a suitable table if we don't already have one */
366 while (current_detail == NULL ||
367 current_index >= current_detail->hash_size) {
369 next = current_detail->others.next;
371 next = cache_list.next;
372 if (next == &cache_list) {
373 current_detail = NULL;
374 spin_unlock(&cache_list_lock);
377 current_detail = list_entry(next, struct cache_detail, others);
378 if (current_detail->nextcheck > get_seconds())
379 current_index = current_detail->hash_size;
382 current_detail->nextcheck = get_seconds()+30*60;
386 /* find a non-empty bucket in the table */
387 while (current_detail &&
388 current_index < current_detail->hash_size &&
389 current_detail->hash_table[current_index] == NULL)
392 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
394 if (current_detail && current_index < current_detail->hash_size) {
395 struct cache_head *ch, **cp;
396 struct cache_detail *d;
398 write_lock(¤t_detail->hash_lock);
400 /* Ok, now to clean this strand */
402 cp = & current_detail->hash_table[current_index];
404 for (; ch; cp= & ch->next, ch= *cp) {
405 if (current_detail->nextcheck > ch->expiry_time)
406 current_detail->nextcheck = ch->expiry_time+1;
407 if (ch->expiry_time >= get_seconds()
408 && ch->last_refresh >= current_detail->flush_time
411 if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
412 cache_dequeue(current_detail, ch);
414 if (atomic_read(&ch->ref.refcount) == 1)
420 current_detail->entries--;
423 write_unlock(¤t_detail->hash_lock);
427 spin_unlock(&cache_list_lock);
429 cache_revisit_request(ch);
433 spin_unlock(&cache_list_lock);
439 * We want to regularly clean the cache, so we need to schedule some work ...
441 static void do_cache_clean(struct work_struct *work)
444 if (cache_clean() == -1)
445 delay = round_jiffies_relative(30*HZ);
447 if (list_empty(&cache_list))
451 schedule_delayed_work(&cache_cleaner, delay);
456 * Clean all caches promptly. This just calls cache_clean
457 * repeatedly until we are sure that every cache has had a chance to
460 void cache_flush(void)
462 while (cache_clean() != -1)
464 while (cache_clean() != -1)
467 EXPORT_SYMBOL_GPL(cache_flush);
469 void cache_purge(struct cache_detail *detail)
471 detail->flush_time = LONG_MAX;
472 detail->nextcheck = get_seconds();
474 detail->flush_time = 1;
476 EXPORT_SYMBOL_GPL(cache_purge);
480 * Deferral and Revisiting of Requests.
482 * If a cache lookup finds a pending entry, we
483 * need to defer the request and revisit it later.
484 * All deferred requests are stored in a hash table,
485 * indexed by "struct cache_head *".
486 * As it may be wasteful to store a whole request
487 * structure, we allow the request to provide a
488 * deferred form, which must contain a
489 * 'struct cache_deferred_req'
490 * This cache_deferred_req contains a method to allow
491 * it to be revisited when cache info is available
494 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
495 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
497 #define DFR_MAX 300 /* ??? */
499 static DEFINE_SPINLOCK(cache_defer_lock);
500 static LIST_HEAD(cache_defer_list);
501 static struct list_head cache_defer_hash[DFR_HASHSIZE];
502 static int cache_defer_cnt;
504 static int cache_defer_req(struct cache_req *req, struct cache_head *item)
506 struct cache_deferred_req *dreq;
507 int hash = DFR_HASH(item);
509 if (cache_defer_cnt >= DFR_MAX) {
510 /* too much in the cache, randomly drop this one,
511 * or continue and drop the oldest below
516 dreq = req->defer(req);
522 spin_lock(&cache_defer_lock);
524 list_add(&dreq->recent, &cache_defer_list);
526 if (cache_defer_hash[hash].next == NULL)
527 INIT_LIST_HEAD(&cache_defer_hash[hash]);
528 list_add(&dreq->hash, &cache_defer_hash[hash]);
530 /* it is in, now maybe clean up */
532 if (++cache_defer_cnt > DFR_MAX) {
533 dreq = list_entry(cache_defer_list.prev,
534 struct cache_deferred_req, recent);
535 list_del(&dreq->recent);
536 list_del(&dreq->hash);
539 spin_unlock(&cache_defer_lock);
542 /* there was one too many */
543 dreq->revisit(dreq, 1);
545 if (!test_bit(CACHE_PENDING, &item->flags)) {
546 /* must have just been validated... */
547 cache_revisit_request(item);
553 static void cache_revisit_request(struct cache_head *item)
555 struct cache_deferred_req *dreq;
556 struct list_head pending;
558 struct list_head *lp;
559 int hash = DFR_HASH(item);
561 INIT_LIST_HEAD(&pending);
562 spin_lock(&cache_defer_lock);
564 lp = cache_defer_hash[hash].next;
566 while (lp != &cache_defer_hash[hash]) {
567 dreq = list_entry(lp, struct cache_deferred_req, hash);
569 if (dreq->item == item) {
570 list_del(&dreq->hash);
571 list_move(&dreq->recent, &pending);
576 spin_unlock(&cache_defer_lock);
578 while (!list_empty(&pending)) {
579 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
580 list_del_init(&dreq->recent);
581 dreq->revisit(dreq, 0);
585 void cache_clean_deferred(void *owner)
587 struct cache_deferred_req *dreq, *tmp;
588 struct list_head pending;
591 INIT_LIST_HEAD(&pending);
592 spin_lock(&cache_defer_lock);
594 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
595 if (dreq->owner == owner) {
596 list_del(&dreq->hash);
597 list_move(&dreq->recent, &pending);
601 spin_unlock(&cache_defer_lock);
603 while (!list_empty(&pending)) {
604 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
605 list_del_init(&dreq->recent);
606 dreq->revisit(dreq, 1);
611 * communicate with user-space
613 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
614 * On read, you get a full request, or block.
615 * On write, an update request is processed.
616 * Poll works if anything to read, and always allows write.
618 * Implemented by linked list of requests. Each open file has
619 * a ->private that also exists in this list. New requests are added
620 * to the end and may wakeup and preceding readers.
621 * New readers are added to the head. If, on read, an item is found with
622 * CACHE_UPCALLING clear, we free it from the list.
626 static DEFINE_SPINLOCK(queue_lock);
627 static DEFINE_MUTEX(queue_io_mutex);
630 struct list_head list;
631 int reader; /* if 0, then request */
633 struct cache_request {
634 struct cache_queue q;
635 struct cache_head *item;
640 struct cache_reader {
641 struct cache_queue q;
642 int offset; /* if non-0, we have a refcnt on next request */
645 static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
646 loff_t *ppos, struct cache_detail *cd)
648 struct cache_reader *rp = filp->private_data;
649 struct cache_request *rq;
650 struct inode *inode = filp->f_path.dentry->d_inode;
656 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent
657 * readers on this file */
659 spin_lock(&queue_lock);
660 /* need to find next request */
661 while (rp->q.list.next != &cd->queue &&
662 list_entry(rp->q.list.next, struct cache_queue, list)
664 struct list_head *next = rp->q.list.next;
665 list_move(&rp->q.list, next);
667 if (rp->q.list.next == &cd->queue) {
668 spin_unlock(&queue_lock);
669 mutex_unlock(&inode->i_mutex);
673 rq = container_of(rp->q.list.next, struct cache_request, q.list);
674 BUG_ON(rq->q.reader);
677 spin_unlock(&queue_lock);
679 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
681 spin_lock(&queue_lock);
682 list_move(&rp->q.list, &rq->q.list);
683 spin_unlock(&queue_lock);
685 if (rp->offset + count > rq->len)
686 count = rq->len - rp->offset;
688 if (copy_to_user(buf, rq->buf + rp->offset, count))
691 if (rp->offset >= rq->len) {
693 spin_lock(&queue_lock);
694 list_move(&rp->q.list, &rq->q.list);
695 spin_unlock(&queue_lock);
700 if (rp->offset == 0) {
701 /* need to release rq */
702 spin_lock(&queue_lock);
704 if (rq->readers == 0 &&
705 !test_bit(CACHE_PENDING, &rq->item->flags)) {
706 list_del(&rq->q.list);
707 spin_unlock(&queue_lock);
708 cache_put(rq->item, cd);
712 spin_unlock(&queue_lock);
716 mutex_unlock(&inode->i_mutex);
717 return err ? err : count;
720 static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
721 size_t count, struct cache_detail *cd)
725 if (copy_from_user(kaddr, buf, count))
728 ret = cd->cache_parse(cd, kaddr, count);
734 static ssize_t cache_slow_downcall(const char __user *buf,
735 size_t count, struct cache_detail *cd)
737 static char write_buf[8192]; /* protected by queue_io_mutex */
738 ssize_t ret = -EINVAL;
740 if (count >= sizeof(write_buf))
742 mutex_lock(&queue_io_mutex);
743 ret = cache_do_downcall(write_buf, buf, count, cd);
744 mutex_unlock(&queue_io_mutex);
749 static ssize_t cache_downcall(struct address_space *mapping,
750 const char __user *buf,
751 size_t count, struct cache_detail *cd)
755 ssize_t ret = -ENOMEM;
757 if (count >= PAGE_CACHE_SIZE)
760 page = find_or_create_page(mapping, 0, GFP_KERNEL);
765 ret = cache_do_downcall(kaddr, buf, count, cd);
768 page_cache_release(page);
771 return cache_slow_downcall(buf, count, cd);
774 static ssize_t cache_write(struct file *filp, const char __user *buf,
775 size_t count, loff_t *ppos,
776 struct cache_detail *cd)
778 struct address_space *mapping = filp->f_mapping;
779 struct inode *inode = filp->f_path.dentry->d_inode;
780 ssize_t ret = -EINVAL;
782 if (!cd->cache_parse)
785 mutex_lock(&inode->i_mutex);
786 ret = cache_downcall(mapping, buf, count, cd);
787 mutex_unlock(&inode->i_mutex);
792 static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
794 static unsigned int cache_poll(struct file *filp, poll_table *wait,
795 struct cache_detail *cd)
798 struct cache_reader *rp = filp->private_data;
799 struct cache_queue *cq;
801 poll_wait(filp, &queue_wait, wait);
803 /* alway allow write */
804 mask = POLL_OUT | POLLWRNORM;
809 spin_lock(&queue_lock);
811 for (cq= &rp->q; &cq->list != &cd->queue;
812 cq = list_entry(cq->list.next, struct cache_queue, list))
814 mask |= POLLIN | POLLRDNORM;
817 spin_unlock(&queue_lock);
821 static int cache_ioctl(struct inode *ino, struct file *filp,
822 unsigned int cmd, unsigned long arg,
823 struct cache_detail *cd)
826 struct cache_reader *rp = filp->private_data;
827 struct cache_queue *cq;
829 if (cmd != FIONREAD || !rp)
832 spin_lock(&queue_lock);
834 /* only find the length remaining in current request,
835 * or the length of the next request
837 for (cq= &rp->q; &cq->list != &cd->queue;
838 cq = list_entry(cq->list.next, struct cache_queue, list))
840 struct cache_request *cr =
841 container_of(cq, struct cache_request, q);
842 len = cr->len - rp->offset;
845 spin_unlock(&queue_lock);
847 return put_user(len, (int __user *)arg);
850 static int cache_open(struct inode *inode, struct file *filp,
851 struct cache_detail *cd)
853 struct cache_reader *rp = NULL;
855 if (!cd || !try_module_get(cd->owner))
857 nonseekable_open(inode, filp);
858 if (filp->f_mode & FMODE_READ) {
859 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
864 atomic_inc(&cd->readers);
865 spin_lock(&queue_lock);
866 list_add(&rp->q.list, &cd->queue);
867 spin_unlock(&queue_lock);
869 filp->private_data = rp;
873 static int cache_release(struct inode *inode, struct file *filp,
874 struct cache_detail *cd)
876 struct cache_reader *rp = filp->private_data;
879 spin_lock(&queue_lock);
881 struct cache_queue *cq;
882 for (cq= &rp->q; &cq->list != &cd->queue;
883 cq = list_entry(cq->list.next, struct cache_queue, list))
885 container_of(cq, struct cache_request, q)
891 list_del(&rp->q.list);
892 spin_unlock(&queue_lock);
894 filp->private_data = NULL;
897 cd->last_close = get_seconds();
898 atomic_dec(&cd->readers);
900 module_put(cd->owner);
906 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
908 struct cache_queue *cq;
909 spin_lock(&queue_lock);
910 list_for_each_entry(cq, &detail->queue, list)
912 struct cache_request *cr = container_of(cq, struct cache_request, q);
915 if (cr->readers != 0)
917 list_del(&cr->q.list);
918 spin_unlock(&queue_lock);
919 cache_put(cr->item, detail);
924 spin_unlock(&queue_lock);
928 * Support routines for text-based upcalls.
929 * Fields are separated by spaces.
930 * Fields are either mangled to quote space tab newline slosh with slosh
931 * or a hexified with a leading \x
932 * Record is terminated with newline.
936 void qword_add(char **bpp, int *lp, char *str)
944 while ((c=*str++) && len)
952 *bp++ = '0' + ((c & 0300)>>6);
953 *bp++ = '0' + ((c & 0070)>>3);
954 *bp++ = '0' + ((c & 0007)>>0);
962 if (c || len <1) len = -1;
970 EXPORT_SYMBOL_GPL(qword_add);
972 void qword_addhex(char **bpp, int *lp, char *buf, int blen)
983 while (blen && len >= 2) {
984 unsigned char c = *buf++;
985 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
986 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
991 if (blen || len<1) len = -1;
999 EXPORT_SYMBOL_GPL(qword_addhex);
1001 static void warn_no_listener(struct cache_detail *detail)
1003 if (detail->last_warn != detail->last_close) {
1004 detail->last_warn = detail->last_close;
1005 if (detail->warn_no_listener)
1006 detail->warn_no_listener(detail, detail->last_close != 0);
1011 * register an upcall request to user-space and queue it up for read() by the
1014 * Each request is at most one page long.
1016 int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
1017 void (*cache_request)(struct cache_detail *,
1018 struct cache_head *,
1024 struct cache_request *crq;
1028 if (atomic_read(&detail->readers) == 0 &&
1029 detail->last_close < get_seconds() - 30) {
1030 warn_no_listener(detail);
1034 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1038 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1044 bp = buf; len = PAGE_SIZE;
1046 cache_request(detail, h, &bp, &len);
1054 crq->item = cache_get(h);
1056 crq->len = PAGE_SIZE - len;
1058 spin_lock(&queue_lock);
1059 list_add_tail(&crq->q.list, &detail->queue);
1060 spin_unlock(&queue_lock);
1061 wake_up(&queue_wait);
1064 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
1067 * parse a message from user-space and pass it
1068 * to an appropriate cache
1069 * Messages are, like requests, separated into fields by
1070 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1073 * reply cachename expiry key ... content....
1075 * key and content are both parsed by cache
1078 #define isodigit(c) (isdigit(c) && c <= '7')
1079 int qword_get(char **bpp, char *dest, int bufsize)
1081 /* return bytes copied, or -1 on error */
1085 while (*bp == ' ') bp++;
1087 if (bp[0] == '\\' && bp[1] == 'x') {
1090 while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) {
1091 int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
1094 byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10;
1100 /* text with \nnn octal quoting */
1101 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1103 isodigit(bp[1]) && (bp[1] <= '3') &&
1106 int byte = (*++bp -'0');
1108 byte = (byte << 3) | (*bp++ - '0');
1109 byte = (byte << 3) | (*bp++ - '0');
1119 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1121 while (*bp == ' ') bp++;
1126 EXPORT_SYMBOL_GPL(qword_get);
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,
1233 struct cache_detail *cd)
1237 if (!cd || !try_module_get(cd->owner))
1239 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
1247 static int content_release(struct inode *inode, struct file *file,
1248 struct cache_detail *cd)
1250 int ret = seq_release_private(inode, file);
1251 module_put(cd->owner);
1255 static int open_flush(struct inode *inode, struct file *file,
1256 struct cache_detail *cd)
1258 if (!cd || !try_module_get(cd->owner))
1260 return nonseekable_open(inode, file);
1263 static int release_flush(struct inode *inode, struct file *file,
1264 struct cache_detail *cd)
1266 module_put(cd->owner);
1270 static ssize_t read_flush(struct file *file, char __user *buf,
1271 size_t count, loff_t *ppos,
1272 struct cache_detail *cd)
1275 unsigned long p = *ppos;
1278 sprintf(tbuf, "%lu\n", cd->flush_time);
1285 if (copy_to_user(buf, (void*)(tbuf+p), len))
1291 static ssize_t write_flush(struct file *file, const char __user *buf,
1292 size_t count, loff_t *ppos,
1293 struct cache_detail *cd)
1298 if (*ppos || count > sizeof(tbuf)-1)
1300 if (copy_from_user(tbuf, buf, count))
1303 flushtime = simple_strtoul(tbuf, &ep, 0);
1304 if (*ep && *ep != '\n')
1307 cd->flush_time = flushtime;
1308 cd->nextcheck = get_seconds();
1315 static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1316 size_t count, loff_t *ppos)
1318 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1320 return cache_read(filp, buf, count, ppos, cd);
1323 static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1324 size_t count, loff_t *ppos)
1326 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1328 return cache_write(filp, buf, count, ppos, cd);
1331 static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1333 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1335 return cache_poll(filp, wait, cd);
1338 static int cache_ioctl_procfs(struct inode *inode, struct file *filp,
1339 unsigned int cmd, unsigned long arg)
1341 struct cache_detail *cd = PDE(inode)->data;
1343 return cache_ioctl(inode, filp, cmd, arg, cd);
1346 static int cache_open_procfs(struct inode *inode, struct file *filp)
1348 struct cache_detail *cd = PDE(inode)->data;
1350 return cache_open(inode, filp, cd);
1353 static int cache_release_procfs(struct inode *inode, struct file *filp)
1355 struct cache_detail *cd = PDE(inode)->data;
1357 return cache_release(inode, filp, cd);
1360 static const struct file_operations cache_file_operations_procfs = {
1361 .owner = THIS_MODULE,
1362 .llseek = no_llseek,
1363 .read = cache_read_procfs,
1364 .write = cache_write_procfs,
1365 .poll = cache_poll_procfs,
1366 .ioctl = cache_ioctl_procfs, /* for FIONREAD */
1367 .open = cache_open_procfs,
1368 .release = cache_release_procfs,
1371 static int content_open_procfs(struct inode *inode, struct file *filp)
1373 struct cache_detail *cd = PDE(inode)->data;
1375 return content_open(inode, filp, cd);
1378 static int content_release_procfs(struct inode *inode, struct file *filp)
1380 struct cache_detail *cd = PDE(inode)->data;
1382 return content_release(inode, filp, cd);
1385 static const struct file_operations content_file_operations_procfs = {
1386 .open = content_open_procfs,
1388 .llseek = seq_lseek,
1389 .release = content_release_procfs,
1392 static int open_flush_procfs(struct inode *inode, struct file *filp)
1394 struct cache_detail *cd = PDE(inode)->data;
1396 return open_flush(inode, filp, cd);
1399 static int release_flush_procfs(struct inode *inode, struct file *filp)
1401 struct cache_detail *cd = PDE(inode)->data;
1403 return release_flush(inode, filp, cd);
1406 static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1407 size_t count, loff_t *ppos)
1409 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1411 return read_flush(filp, buf, count, ppos, cd);
1414 static ssize_t write_flush_procfs(struct file *filp,
1415 const char __user *buf,
1416 size_t count, loff_t *ppos)
1418 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1420 return write_flush(filp, buf, count, ppos, cd);
1423 static const struct file_operations cache_flush_operations_procfs = {
1424 .open = open_flush_procfs,
1425 .read = read_flush_procfs,
1426 .write = write_flush_procfs,
1427 .release = release_flush_procfs,
1430 static void remove_cache_proc_entries(struct cache_detail *cd)
1432 if (cd->u.procfs.proc_ent == NULL)
1434 if (cd->u.procfs.flush_ent)
1435 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1436 if (cd->u.procfs.channel_ent)
1437 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1438 if (cd->u.procfs.content_ent)
1439 remove_proc_entry("content", cd->u.procfs.proc_ent);
1440 cd->u.procfs.proc_ent = NULL;
1441 remove_proc_entry(cd->name, proc_net_rpc);
1444 #ifdef CONFIG_PROC_FS
1445 static int create_cache_proc_entries(struct cache_detail *cd)
1447 struct proc_dir_entry *p;
1449 cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc);
1450 if (cd->u.procfs.proc_ent == NULL)
1452 cd->u.procfs.channel_ent = NULL;
1453 cd->u.procfs.content_ent = NULL;
1455 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1456 cd->u.procfs.proc_ent,
1457 &cache_flush_operations_procfs, cd);
1458 cd->u.procfs.flush_ent = p;
1462 if (cd->cache_upcall || cd->cache_parse) {
1463 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1464 cd->u.procfs.proc_ent,
1465 &cache_file_operations_procfs, cd);
1466 cd->u.procfs.channel_ent = p;
1470 if (cd->cache_show) {
1471 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
1472 cd->u.procfs.proc_ent,
1473 &content_file_operations_procfs, cd);
1474 cd->u.procfs.content_ent = p;
1480 remove_cache_proc_entries(cd);
1483 #else /* CONFIG_PROC_FS */
1484 static int create_cache_proc_entries(struct cache_detail *cd)
1490 int cache_register(struct cache_detail *cd)
1494 sunrpc_init_cache_detail(cd);
1495 ret = create_cache_proc_entries(cd);
1497 sunrpc_destroy_cache_detail(cd);
1500 EXPORT_SYMBOL_GPL(cache_register);
1502 void cache_unregister(struct cache_detail *cd)
1504 remove_cache_proc_entries(cd);
1505 sunrpc_destroy_cache_detail(cd);
1507 EXPORT_SYMBOL_GPL(cache_unregister);
1509 static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1510 size_t count, loff_t *ppos)
1512 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1514 return cache_read(filp, buf, count, ppos, cd);
1517 static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1518 size_t count, loff_t *ppos)
1520 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1522 return cache_write(filp, buf, count, ppos, cd);
1525 static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1527 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1529 return cache_poll(filp, wait, cd);
1532 static int cache_ioctl_pipefs(struct inode *inode, struct file *filp,
1533 unsigned int cmd, unsigned long arg)
1535 struct cache_detail *cd = RPC_I(inode)->private;
1537 return cache_ioctl(inode, filp, cmd, arg, cd);
1540 static int cache_open_pipefs(struct inode *inode, struct file *filp)
1542 struct cache_detail *cd = RPC_I(inode)->private;
1544 return cache_open(inode, filp, cd);
1547 static int cache_release_pipefs(struct inode *inode, struct file *filp)
1549 struct cache_detail *cd = RPC_I(inode)->private;
1551 return cache_release(inode, filp, cd);
1554 const struct file_operations cache_file_operations_pipefs = {
1555 .owner = THIS_MODULE,
1556 .llseek = no_llseek,
1557 .read = cache_read_pipefs,
1558 .write = cache_write_pipefs,
1559 .poll = cache_poll_pipefs,
1560 .ioctl = cache_ioctl_pipefs, /* for FIONREAD */
1561 .open = cache_open_pipefs,
1562 .release = cache_release_pipefs,
1565 static int content_open_pipefs(struct inode *inode, struct file *filp)
1567 struct cache_detail *cd = RPC_I(inode)->private;
1569 return content_open(inode, filp, cd);
1572 static int content_release_pipefs(struct inode *inode, struct file *filp)
1574 struct cache_detail *cd = RPC_I(inode)->private;
1576 return content_release(inode, filp, cd);
1579 const struct file_operations content_file_operations_pipefs = {
1580 .open = content_open_pipefs,
1582 .llseek = seq_lseek,
1583 .release = content_release_pipefs,
1586 static int open_flush_pipefs(struct inode *inode, struct file *filp)
1588 struct cache_detail *cd = RPC_I(inode)->private;
1590 return open_flush(inode, filp, cd);
1593 static int release_flush_pipefs(struct inode *inode, struct file *filp)
1595 struct cache_detail *cd = RPC_I(inode)->private;
1597 return release_flush(inode, filp, cd);
1600 static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1601 size_t count, loff_t *ppos)
1603 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1605 return read_flush(filp, buf, count, ppos, cd);
1608 static ssize_t write_flush_pipefs(struct file *filp,
1609 const char __user *buf,
1610 size_t count, loff_t *ppos)
1612 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1614 return write_flush(filp, buf, count, ppos, cd);
1617 const struct file_operations cache_flush_operations_pipefs = {
1618 .open = open_flush_pipefs,
1619 .read = read_flush_pipefs,
1620 .write = write_flush_pipefs,
1621 .release = release_flush_pipefs,
1624 int sunrpc_cache_register_pipefs(struct dentry *parent,
1625 const char *name, mode_t umode,
1626 struct cache_detail *cd)
1632 sunrpc_init_cache_detail(cd);
1634 q.len = strlen(name);
1635 q.hash = full_name_hash(q.name, q.len);
1636 dir = rpc_create_cache_dir(parent, &q, umode, cd);
1638 cd->u.pipefs.dir = dir;
1640 sunrpc_destroy_cache_detail(cd);
1645 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1647 void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1649 rpc_remove_cache_dir(cd->u.pipefs.dir);
1650 cd->u.pipefs.dir = NULL;
1651 sunrpc_destroy_cache_detail(cd);
1653 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);