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("flush", S_IFREG
|S_IRUSR
|S_IWUSR
,
320 cd
->proc_ent
, &cache_flush_operations
);
324 p
->owner
= cd
->owner
;
327 if (cd
->cache_request
|| cd
->cache_parse
) {
328 p
= proc_create("channel", S_IFREG
|S_IRUSR
|S_IWUSR
,
329 cd
->proc_ent
, &cache_file_operations
);
333 p
->owner
= cd
->owner
;
336 if (cd
->cache_show
) {
337 p
= proc_create("content", S_IFREG
|S_IRUSR
|S_IWUSR
,
338 cd
->proc_ent
, &content_file_operations
);
342 p
->owner
= cd
->owner
;
347 remove_cache_proc_entries(cd
);
350 #else /* CONFIG_PROC_FS */
351 static int create_cache_proc_entries(struct cache_detail
*cd
)
357 int cache_register(struct cache_detail
*cd
)
361 ret
= create_cache_proc_entries(cd
);
364 rwlock_init(&cd
->hash_lock
);
365 INIT_LIST_HEAD(&cd
->queue
);
366 spin_lock(&cache_list_lock
);
369 atomic_set(&cd
->readers
, 0);
372 list_add(&cd
->others
, &cache_list
);
373 spin_unlock(&cache_list_lock
);
375 /* start the cleaning process */
376 schedule_delayed_work(&cache_cleaner
, 0);
379 EXPORT_SYMBOL(cache_register
);
381 void cache_unregister(struct cache_detail
*cd
)
384 spin_lock(&cache_list_lock
);
385 write_lock(&cd
->hash_lock
);
386 if (cd
->entries
|| atomic_read(&cd
->inuse
)) {
387 write_unlock(&cd
->hash_lock
);
388 spin_unlock(&cache_list_lock
);
391 if (current_detail
== cd
)
392 current_detail
= NULL
;
393 list_del_init(&cd
->others
);
394 write_unlock(&cd
->hash_lock
);
395 spin_unlock(&cache_list_lock
);
396 remove_cache_proc_entries(cd
);
397 if (list_empty(&cache_list
)) {
398 /* module must be being unloaded so its safe to kill the worker */
399 cancel_delayed_work_sync(&cache_cleaner
);
403 printk(KERN_ERR
"nfsd: failed to unregister %s cache\n", cd
->name
);
405 EXPORT_SYMBOL(cache_unregister
);
407 /* clean cache tries to find something to clean
409 * It returns 1 if it cleaned something,
410 * 0 if it didn't find anything this time
411 * -1 if it fell off the end of the list.
413 static int cache_clean(void)
416 struct list_head
*next
;
418 spin_lock(&cache_list_lock
);
420 /* find a suitable table if we don't already have one */
421 while (current_detail
== NULL
||
422 current_index
>= current_detail
->hash_size
) {
424 next
= current_detail
->others
.next
;
426 next
= cache_list
.next
;
427 if (next
== &cache_list
) {
428 current_detail
= NULL
;
429 spin_unlock(&cache_list_lock
);
432 current_detail
= list_entry(next
, struct cache_detail
, others
);
433 if (current_detail
->nextcheck
> get_seconds())
434 current_index
= current_detail
->hash_size
;
437 current_detail
->nextcheck
= get_seconds()+30*60;
441 /* find a non-empty bucket in the table */
442 while (current_detail
&&
443 current_index
< current_detail
->hash_size
&&
444 current_detail
->hash_table
[current_index
] == NULL
)
447 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
449 if (current_detail
&& current_index
< current_detail
->hash_size
) {
450 struct cache_head
*ch
, **cp
;
451 struct cache_detail
*d
;
453 write_lock(¤t_detail
->hash_lock
);
455 /* Ok, now to clean this strand */
457 cp
= & current_detail
->hash_table
[current_index
];
459 for (; ch
; cp
= & ch
->next
, ch
= *cp
) {
460 if (current_detail
->nextcheck
> ch
->expiry_time
)
461 current_detail
->nextcheck
= ch
->expiry_time
+1;
462 if (ch
->expiry_time
>= get_seconds()
463 && ch
->last_refresh
>= current_detail
->flush_time
466 if (test_and_clear_bit(CACHE_PENDING
, &ch
->flags
))
467 queue_loose(current_detail
, ch
);
469 if (atomic_read(&ch
->ref
.refcount
) == 1)
475 current_detail
->entries
--;
478 write_unlock(¤t_detail
->hash_lock
);
482 spin_unlock(&cache_list_lock
);
486 spin_unlock(&cache_list_lock
);
492 * We want to regularly clean the cache, so we need to schedule some work ...
494 static void do_cache_clean(struct work_struct
*work
)
497 if (cache_clean() == -1)
500 if (list_empty(&cache_list
))
504 schedule_delayed_work(&cache_cleaner
, delay
);
509 * Clean all caches promptly. This just calls cache_clean
510 * repeatedly until we are sure that every cache has had a chance to
513 void cache_flush(void)
515 while (cache_clean() != -1)
517 while (cache_clean() != -1)
520 EXPORT_SYMBOL(cache_flush
);
522 void cache_purge(struct cache_detail
*detail
)
524 detail
->flush_time
= LONG_MAX
;
525 detail
->nextcheck
= get_seconds();
527 detail
->flush_time
= 1;
529 EXPORT_SYMBOL(cache_purge
);
533 * Deferral and Revisiting of Requests.
535 * If a cache lookup finds a pending entry, we
536 * need to defer the request and revisit it later.
537 * All deferred requests are stored in a hash table,
538 * indexed by "struct cache_head *".
539 * As it may be wasteful to store a whole request
540 * structure, we allow the request to provide a
541 * deferred form, which must contain a
542 * 'struct cache_deferred_req'
543 * This cache_deferred_req contains a method to allow
544 * it to be revisited when cache info is available
547 #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
548 #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
550 #define DFR_MAX 300 /* ??? */
552 static DEFINE_SPINLOCK(cache_defer_lock
);
553 static LIST_HEAD(cache_defer_list
);
554 static struct list_head cache_defer_hash
[DFR_HASHSIZE
];
555 static int cache_defer_cnt
;
557 static int cache_defer_req(struct cache_req
*req
, struct cache_head
*item
)
559 struct cache_deferred_req
*dreq
;
560 int hash
= DFR_HASH(item
);
562 if (cache_defer_cnt
>= DFR_MAX
) {
563 /* too much in the cache, randomly drop this one,
564 * or continue and drop the oldest below
569 dreq
= req
->defer(req
);
575 spin_lock(&cache_defer_lock
);
577 list_add(&dreq
->recent
, &cache_defer_list
);
579 if (cache_defer_hash
[hash
].next
== NULL
)
580 INIT_LIST_HEAD(&cache_defer_hash
[hash
]);
581 list_add(&dreq
->hash
, &cache_defer_hash
[hash
]);
583 /* it is in, now maybe clean up */
585 if (++cache_defer_cnt
> DFR_MAX
) {
586 dreq
= list_entry(cache_defer_list
.prev
,
587 struct cache_deferred_req
, recent
);
588 list_del(&dreq
->recent
);
589 list_del(&dreq
->hash
);
592 spin_unlock(&cache_defer_lock
);
595 /* there was one too many */
596 dreq
->revisit(dreq
, 1);
598 if (!test_bit(CACHE_PENDING
, &item
->flags
)) {
599 /* must have just been validated... */
600 cache_revisit_request(item
);
605 static void cache_revisit_request(struct cache_head
*item
)
607 struct cache_deferred_req
*dreq
;
608 struct list_head pending
;
610 struct list_head
*lp
;
611 int hash
= DFR_HASH(item
);
613 INIT_LIST_HEAD(&pending
);
614 spin_lock(&cache_defer_lock
);
616 lp
= cache_defer_hash
[hash
].next
;
618 while (lp
!= &cache_defer_hash
[hash
]) {
619 dreq
= list_entry(lp
, struct cache_deferred_req
, hash
);
621 if (dreq
->item
== item
) {
622 list_del(&dreq
->hash
);
623 list_move(&dreq
->recent
, &pending
);
628 spin_unlock(&cache_defer_lock
);
630 while (!list_empty(&pending
)) {
631 dreq
= list_entry(pending
.next
, struct cache_deferred_req
, recent
);
632 list_del_init(&dreq
->recent
);
633 dreq
->revisit(dreq
, 0);
637 void cache_clean_deferred(void *owner
)
639 struct cache_deferred_req
*dreq
, *tmp
;
640 struct list_head pending
;
643 INIT_LIST_HEAD(&pending
);
644 spin_lock(&cache_defer_lock
);
646 list_for_each_entry_safe(dreq
, tmp
, &cache_defer_list
, recent
) {
647 if (dreq
->owner
== owner
) {
648 list_del(&dreq
->hash
);
649 list_move(&dreq
->recent
, &pending
);
653 spin_unlock(&cache_defer_lock
);
655 while (!list_empty(&pending
)) {
656 dreq
= list_entry(pending
.next
, struct cache_deferred_req
, recent
);
657 list_del_init(&dreq
->recent
);
658 dreq
->revisit(dreq
, 1);
663 * communicate with user-space
665 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
666 * On read, you get a full request, or block.
667 * On write, an update request is processed.
668 * Poll works if anything to read, and always allows write.
670 * Implemented by linked list of requests. Each open file has
671 * a ->private that also exists in this list. New requests are added
672 * to the end and may wakeup and preceding readers.
673 * New readers are added to the head. If, on read, an item is found with
674 * CACHE_UPCALLING clear, we free it from the list.
678 static DEFINE_SPINLOCK(queue_lock
);
679 static DEFINE_MUTEX(queue_io_mutex
);
682 struct list_head list
;
683 int reader
; /* if 0, then request */
685 struct cache_request
{
686 struct cache_queue q
;
687 struct cache_head
*item
;
692 struct cache_reader
{
693 struct cache_queue q
;
694 int offset
; /* if non-0, we have a refcnt on next request */
698 cache_read(struct file
*filp
, char __user
*buf
, size_t count
, loff_t
*ppos
)
700 struct cache_reader
*rp
= filp
->private_data
;
701 struct cache_request
*rq
;
702 struct cache_detail
*cd
= PDE(filp
->f_path
.dentry
->d_inode
)->data
;
708 mutex_lock(&queue_io_mutex
); /* protect against multiple concurrent
709 * readers on this file */
711 spin_lock(&queue_lock
);
712 /* need to find next request */
713 while (rp
->q
.list
.next
!= &cd
->queue
&&
714 list_entry(rp
->q
.list
.next
, struct cache_queue
, list
)
716 struct list_head
*next
= rp
->q
.list
.next
;
717 list_move(&rp
->q
.list
, next
);
719 if (rp
->q
.list
.next
== &cd
->queue
) {
720 spin_unlock(&queue_lock
);
721 mutex_unlock(&queue_io_mutex
);
725 rq
= container_of(rp
->q
.list
.next
, struct cache_request
, q
.list
);
726 BUG_ON(rq
->q
.reader
);
729 spin_unlock(&queue_lock
);
731 if (rp
->offset
== 0 && !test_bit(CACHE_PENDING
, &rq
->item
->flags
)) {
733 spin_lock(&queue_lock
);
734 list_move(&rp
->q
.list
, &rq
->q
.list
);
735 spin_unlock(&queue_lock
);
737 if (rp
->offset
+ count
> rq
->len
)
738 count
= rq
->len
- rp
->offset
;
740 if (copy_to_user(buf
, rq
->buf
+ rp
->offset
, count
))
743 if (rp
->offset
>= rq
->len
) {
745 spin_lock(&queue_lock
);
746 list_move(&rp
->q
.list
, &rq
->q
.list
);
747 spin_unlock(&queue_lock
);
752 if (rp
->offset
== 0) {
753 /* need to release rq */
754 spin_lock(&queue_lock
);
756 if (rq
->readers
== 0 &&
757 !test_bit(CACHE_PENDING
, &rq
->item
->flags
)) {
758 list_del(&rq
->q
.list
);
759 spin_unlock(&queue_lock
);
760 cache_put(rq
->item
, cd
);
764 spin_unlock(&queue_lock
);
768 mutex_unlock(&queue_io_mutex
);
769 return err
? err
: count
;
772 static char write_buf
[8192]; /* protected by queue_io_mutex */
775 cache_write(struct file
*filp
, const char __user
*buf
, size_t count
,
779 struct cache_detail
*cd
= PDE(filp
->f_path
.dentry
->d_inode
)->data
;
783 if (count
>= sizeof(write_buf
))
786 mutex_lock(&queue_io_mutex
);
788 if (copy_from_user(write_buf
, buf
, count
)) {
789 mutex_unlock(&queue_io_mutex
);
792 write_buf
[count
] = '\0';
794 err
= cd
->cache_parse(cd
, write_buf
, count
);
798 mutex_unlock(&queue_io_mutex
);
799 return err
? err
: count
;
802 static DECLARE_WAIT_QUEUE_HEAD(queue_wait
);
805 cache_poll(struct file
*filp
, poll_table
*wait
)
808 struct cache_reader
*rp
= filp
->private_data
;
809 struct cache_queue
*cq
;
810 struct cache_detail
*cd
= PDE(filp
->f_path
.dentry
->d_inode
)->data
;
812 poll_wait(filp
, &queue_wait
, wait
);
814 /* alway allow write */
815 mask
= POLL_OUT
| POLLWRNORM
;
820 spin_lock(&queue_lock
);
822 for (cq
= &rp
->q
; &cq
->list
!= &cd
->queue
;
823 cq
= list_entry(cq
->list
.next
, struct cache_queue
, list
))
825 mask
|= POLLIN
| POLLRDNORM
;
828 spin_unlock(&queue_lock
);
833 cache_ioctl(struct inode
*ino
, struct file
*filp
,
834 unsigned int cmd
, unsigned long arg
)
837 struct cache_reader
*rp
= filp
->private_data
;
838 struct cache_queue
*cq
;
839 struct cache_detail
*cd
= PDE(ino
)->data
;
841 if (cmd
!= FIONREAD
|| !rp
)
844 spin_lock(&queue_lock
);
846 /* only find the length remaining in current request,
847 * or the length of the next request
849 for (cq
= &rp
->q
; &cq
->list
!= &cd
->queue
;
850 cq
= list_entry(cq
->list
.next
, struct cache_queue
, list
))
852 struct cache_request
*cr
=
853 container_of(cq
, struct cache_request
, q
);
854 len
= cr
->len
- rp
->offset
;
857 spin_unlock(&queue_lock
);
859 return put_user(len
, (int __user
*)arg
);
863 cache_open(struct inode
*inode
, struct file
*filp
)
865 struct cache_reader
*rp
= NULL
;
867 nonseekable_open(inode
, filp
);
868 if (filp
->f_mode
& FMODE_READ
) {
869 struct cache_detail
*cd
= PDE(inode
)->data
;
871 rp
= kmalloc(sizeof(*rp
), GFP_KERNEL
);
876 atomic_inc(&cd
->readers
);
877 spin_lock(&queue_lock
);
878 list_add(&rp
->q
.list
, &cd
->queue
);
879 spin_unlock(&queue_lock
);
881 filp
->private_data
= rp
;
886 cache_release(struct inode
*inode
, struct file
*filp
)
888 struct cache_reader
*rp
= filp
->private_data
;
889 struct cache_detail
*cd
= PDE(inode
)->data
;
892 spin_lock(&queue_lock
);
894 struct cache_queue
*cq
;
895 for (cq
= &rp
->q
; &cq
->list
!= &cd
->queue
;
896 cq
= list_entry(cq
->list
.next
, struct cache_queue
, list
))
898 container_of(cq
, struct cache_request
, q
)
904 list_del(&rp
->q
.list
);
905 spin_unlock(&queue_lock
);
907 filp
->private_data
= NULL
;
910 cd
->last_close
= get_seconds();
911 atomic_dec(&cd
->readers
);
918 static const struct file_operations cache_file_operations
= {
919 .owner
= THIS_MODULE
,
922 .write
= cache_write
,
924 .ioctl
= cache_ioctl
, /* for FIONREAD */
926 .release
= cache_release
,
930 static void queue_loose(struct cache_detail
*detail
, struct cache_head
*ch
)
932 struct cache_queue
*cq
;
933 spin_lock(&queue_lock
);
934 list_for_each_entry(cq
, &detail
->queue
, list
)
936 struct cache_request
*cr
= container_of(cq
, struct cache_request
, q
);
939 if (cr
->readers
!= 0)
941 list_del(&cr
->q
.list
);
942 spin_unlock(&queue_lock
);
943 cache_put(cr
->item
, detail
);
948 spin_unlock(&queue_lock
);
952 * Support routines for text-based upcalls.
953 * Fields are separated by spaces.
954 * Fields are either mangled to quote space tab newline slosh with slosh
955 * or a hexified with a leading \x
956 * Record is terminated with newline.
960 void qword_add(char **bpp
, int *lp
, char *str
)
968 while ((c
=*str
++) && len
)
976 *bp
++ = '0' + ((c
& 0300)>>6);
977 *bp
++ = '0' + ((c
& 0070)>>3);
978 *bp
++ = '0' + ((c
& 0007)>>0);
986 if (c
|| len
<1) len
= -1;
994 EXPORT_SYMBOL(qword_add
);
996 void qword_addhex(char **bpp
, int *lp
, char *buf
, int blen
)
1001 if (len
< 0) return;
1007 while (blen
&& len
>= 2) {
1008 unsigned char c
= *buf
++;
1009 *bp
++ = '0' + ((c
&0xf0)>>4) + (c
>=0xa0)*('a'-'9'-1);
1010 *bp
++ = '0' + (c
&0x0f) + ((c
&0x0f)>=0x0a)*('a'-'9'-1);
1015 if (blen
|| len
<1) len
= -1;
1023 EXPORT_SYMBOL(qword_addhex
);
1025 static void warn_no_listener(struct cache_detail
*detail
)
1027 if (detail
->last_warn
!= detail
->last_close
) {
1028 detail
->last_warn
= detail
->last_close
;
1029 if (detail
->warn_no_listener
)
1030 detail
->warn_no_listener(detail
);
1035 * register an upcall request to user-space.
1036 * Each request is at most one page long.
1038 static int cache_make_upcall(struct cache_detail
*detail
, struct cache_head
*h
)
1042 struct cache_request
*crq
;
1046 if (detail
->cache_request
== NULL
)
1049 if (atomic_read(&detail
->readers
) == 0 &&
1050 detail
->last_close
< get_seconds() - 30) {
1051 warn_no_listener(detail
);
1055 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
1059 crq
= kmalloc(sizeof (*crq
), GFP_KERNEL
);
1065 bp
= buf
; len
= PAGE_SIZE
;
1067 detail
->cache_request(detail
, h
, &bp
, &len
);
1075 crq
->item
= cache_get(h
);
1077 crq
->len
= PAGE_SIZE
- len
;
1079 spin_lock(&queue_lock
);
1080 list_add_tail(&crq
->q
.list
, &detail
->queue
);
1081 spin_unlock(&queue_lock
);
1082 wake_up(&queue_wait
);
1087 * parse a message from user-space and pass it
1088 * to an appropriate cache
1089 * Messages are, like requests, separated into fields by
1090 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1093 * reply cachename expiry key ... content....
1095 * key and content are both parsed by cache
1098 #define isodigit(c) (isdigit(c) && c <= '7')
1099 int qword_get(char **bpp
, char *dest
, int bufsize
)
1101 /* return bytes copied, or -1 on error */
1105 while (*bp
== ' ') bp
++;
1107 if (bp
[0] == '\\' && bp
[1] == 'x') {
1110 while (isxdigit(bp
[0]) && isxdigit(bp
[1]) && len
< bufsize
) {
1111 int byte
= isdigit(*bp
) ? *bp
-'0' : toupper(*bp
)-'A'+10;
1114 byte
|= isdigit(*bp
) ? *bp
-'0' : toupper(*bp
)-'A'+10;
1120 /* text with \nnn octal quoting */
1121 while (*bp
!= ' ' && *bp
!= '\n' && *bp
&& len
< bufsize
-1) {
1123 isodigit(bp
[1]) && (bp
[1] <= '3') &&
1126 int byte
= (*++bp
-'0');
1128 byte
= (byte
<< 3) | (*bp
++ - '0');
1129 byte
= (byte
<< 3) | (*bp
++ - '0');
1139 if (*bp
!= ' ' && *bp
!= '\n' && *bp
!= '\0')
1141 while (*bp
== ' ') bp
++;
1146 EXPORT_SYMBOL(qword_get
);
1150 * support /proc/sunrpc/cache/$CACHENAME/content
1152 * We call ->cache_show passing NULL for the item to
1153 * get a header, then pass each real item in the cache
1157 struct cache_detail
*cd
;
1160 static void *c_start(struct seq_file
*m
, loff_t
*pos
)
1161 __acquires(cd
->hash_lock
)
1164 unsigned hash
, entry
;
1165 struct cache_head
*ch
;
1166 struct cache_detail
*cd
= ((struct handle
*)m
->private)->cd
;
1169 read_lock(&cd
->hash_lock
);
1171 return SEQ_START_TOKEN
;
1173 entry
= n
& ((1LL<<32) - 1);
1175 for (ch
=cd
->hash_table
[hash
]; ch
; ch
=ch
->next
)
1178 n
&= ~((1LL<<32) - 1);
1182 } while(hash
< cd
->hash_size
&&
1183 cd
->hash_table
[hash
]==NULL
);
1184 if (hash
>= cd
->hash_size
)
1187 return cd
->hash_table
[hash
];
1190 static void *c_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
1192 struct cache_head
*ch
= p
;
1193 int hash
= (*pos
>> 32);
1194 struct cache_detail
*cd
= ((struct handle
*)m
->private)->cd
;
1196 if (p
== SEQ_START_TOKEN
)
1198 else if (ch
->next
== NULL
) {
1205 *pos
&= ~((1LL<<32) - 1);
1206 while (hash
< cd
->hash_size
&&
1207 cd
->hash_table
[hash
] == NULL
) {
1211 if (hash
>= cd
->hash_size
)
1214 return cd
->hash_table
[hash
];
1217 static void c_stop(struct seq_file
*m
, void *p
)
1218 __releases(cd
->hash_lock
)
1220 struct cache_detail
*cd
= ((struct handle
*)m
->private)->cd
;
1221 read_unlock(&cd
->hash_lock
);
1224 static int c_show(struct seq_file
*m
, void *p
)
1226 struct cache_head
*cp
= p
;
1227 struct cache_detail
*cd
= ((struct handle
*)m
->private)->cd
;
1229 if (p
== SEQ_START_TOKEN
)
1230 return cd
->cache_show(m
, cd
, NULL
);
1233 seq_printf(m
, "# expiry=%ld refcnt=%d flags=%lx\n",
1234 cp
->expiry_time
, atomic_read(&cp
->ref
.refcount
), cp
->flags
);
1236 if (cache_check(cd
, cp
, NULL
))
1237 /* cache_check does a cache_put on failure */
1238 seq_printf(m
, "# ");
1242 return cd
->cache_show(m
, cd
, cp
);
1245 static const struct seq_operations cache_content_op
= {
1252 static int content_open(struct inode
*inode
, struct file
*file
)
1255 struct cache_detail
*cd
= PDE(inode
)->data
;
1257 han
= __seq_open_private(file
, &cache_content_op
, sizeof(*han
));
1265 static const struct file_operations content_file_operations
= {
1266 .open
= content_open
,
1268 .llseek
= seq_lseek
,
1269 .release
= seq_release_private
,
1272 static ssize_t
read_flush(struct file
*file
, char __user
*buf
,
1273 size_t count
, loff_t
*ppos
)
1275 struct cache_detail
*cd
= PDE(file
->f_path
.dentry
->d_inode
)->data
;
1277 unsigned long p
= *ppos
;
1280 sprintf(tbuf
, "%lu\n", cd
->flush_time
);
1287 if (copy_to_user(buf
, (void*)(tbuf
+p
), len
))
1293 static ssize_t
write_flush(struct file
* file
, const char __user
* buf
,
1294 size_t count
, loff_t
*ppos
)
1296 struct cache_detail
*cd
= PDE(file
->f_path
.dentry
->d_inode
)->data
;
1300 if (*ppos
|| count
> sizeof(tbuf
)-1)
1302 if (copy_from_user(tbuf
, buf
, count
))
1305 flushtime
= simple_strtoul(tbuf
, &ep
, 0);
1306 if (*ep
&& *ep
!= '\n')
1309 cd
->flush_time
= flushtime
;
1310 cd
->nextcheck
= get_seconds();
1317 static const struct file_operations cache_flush_operations
= {
1318 .open
= nonseekable_open
,
1320 .write
= write_flush
,