blob: 72ad836e4fe05d7e5d9153918e5d8c1dacecc4a5 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * net/sunrpc/cache.c
3 *
4 * Generic code for various authentication-related caches
5 * used by sunrpc clients and servers.
6 *
7 * Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au>
8 *
9 * Released under terms in GPL version 2. See COPYING.
10 *
11 */
12
13#include <linux/types.h>
14#include <linux/fs.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>
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080029#include <linux/mutex.h>
Trond Myklebustda770052009-08-09 15:14:28 -040030#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <asm/ioctls.h>
32#include <linux/sunrpc/types.h>
33#include <linux/sunrpc/cache.h>
34#include <linux/sunrpc/stats.h>
Trond Myklebust8854e822009-08-09 15:14:30 -040035#include <linux/sunrpc/rpc_pipe_fs.h>
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +040036#include "netns.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38#define RPCDBG_FACILITY RPCDBG_CACHE
39
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -050040static bool cache_defer_req(struct cache_req *req, struct cache_head *item);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041static void cache_revisit_request(struct cache_head *item);
42
Adrian Bunk74cae612006-03-27 01:15:10 -080043static void cache_init(struct cache_head *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
NeilBrownc5b29f82010-08-12 16:55:22 +100045 time_t now = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 h->next = NULL;
47 h->flags = 0;
NeilBrownbaab9352006-03-27 01:15:09 -080048 kref_init(&h->ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 h->expiry_time = now + CACHE_NEW_EXPIRY;
50 h->last_refresh = now;
51}
52
NeilBrown2f50d8b2010-02-03 17:31:31 +110053static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h)
54{
NeilBrownc5b29f82010-08-12 16:55:22 +100055 return (h->expiry_time < seconds_since_boot()) ||
NeilBrown2f50d8b2010-02-03 17:31:31 +110056 (detail->flush_time > h->last_refresh);
57}
58
NeilBrown15a5f6b2006-03-27 01:15:02 -080059struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
60 struct cache_head *key, int hash)
61{
62 struct cache_head **head, **hp;
NeilBrownd202cce2010-02-03 17:31:31 +110063 struct cache_head *new = NULL, *freeme = NULL;
NeilBrown15a5f6b2006-03-27 01:15:02 -080064
65 head = &detail->hash_table[hash];
66
67 read_lock(&detail->hash_lock);
68
69 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
70 struct cache_head *tmp = *hp;
71 if (detail->match(tmp, key)) {
NeilBrownd202cce2010-02-03 17:31:31 +110072 if (cache_is_expired(detail, tmp))
73 /* This entry is expired, we will discard it. */
74 break;
NeilBrown15a5f6b2006-03-27 01:15:02 -080075 cache_get(tmp);
76 read_unlock(&detail->hash_lock);
77 return tmp;
78 }
79 }
80 read_unlock(&detail->hash_lock);
81 /* Didn't find anything, insert an empty entry */
82
83 new = detail->alloc();
84 if (!new)
85 return NULL;
Neil Brown2f349312006-08-05 12:14:29 -070086 /* must fully initialise 'new', else
87 * we might get lose if we need to
88 * cache_put it soon.
89 */
NeilBrown15a5f6b2006-03-27 01:15:02 -080090 cache_init(new);
Neil Brown2f349312006-08-05 12:14:29 -070091 detail->init(new, key);
NeilBrown15a5f6b2006-03-27 01:15:02 -080092
93 write_lock(&detail->hash_lock);
94
95 /* check if entry appeared while we slept */
96 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
97 struct cache_head *tmp = *hp;
98 if (detail->match(tmp, key)) {
NeilBrownd202cce2010-02-03 17:31:31 +110099 if (cache_is_expired(detail, tmp)) {
100 *hp = tmp->next;
101 tmp->next = NULL;
102 detail->entries --;
103 freeme = tmp;
104 break;
105 }
NeilBrown15a5f6b2006-03-27 01:15:02 -0800106 cache_get(tmp);
107 write_unlock(&detail->hash_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800108 cache_put(new, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800109 return tmp;
110 }
111 }
NeilBrown15a5f6b2006-03-27 01:15:02 -0800112 new->next = *head;
113 *head = new;
114 detail->entries++;
115 cache_get(new);
116 write_unlock(&detail->hash_lock);
117
NeilBrownd202cce2010-02-03 17:31:31 +1100118 if (freeme)
119 cache_put(freeme, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800120 return new;
121}
Trond Myklebust24c37672008-12-23 16:30:12 -0500122EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800123
NeilBrownebd0cb12006-03-27 01:15:08 -0800124
NeilBrownf866a812009-08-04 15:22:38 +1000125static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
NeilBrownebd0cb12006-03-27 01:15:08 -0800126
NeilBrown908329f2009-09-09 16:32:54 +1000127static void cache_fresh_locked(struct cache_head *head, time_t expiry)
NeilBrownebd0cb12006-03-27 01:15:08 -0800128{
129 head->expiry_time = expiry;
NeilBrownc5b29f82010-08-12 16:55:22 +1000130 head->last_refresh = seconds_since_boot();
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500131 smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
NeilBrown908329f2009-09-09 16:32:54 +1000132 set_bit(CACHE_VALID, &head->flags);
NeilBrownebd0cb12006-03-27 01:15:08 -0800133}
134
135static void cache_fresh_unlocked(struct cache_head *head,
NeilBrown908329f2009-09-09 16:32:54 +1000136 struct cache_detail *detail)
NeilBrownebd0cb12006-03-27 01:15:08 -0800137{
NeilBrownebd0cb12006-03-27 01:15:08 -0800138 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
139 cache_revisit_request(head);
NeilBrownf866a812009-08-04 15:22:38 +1000140 cache_dequeue(detail, head);
NeilBrownebd0cb12006-03-27 01:15:08 -0800141 }
142}
143
NeilBrown15a5f6b2006-03-27 01:15:02 -0800144struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
145 struct cache_head *new, struct cache_head *old, int hash)
146{
147 /* The 'old' entry is to be replaced by 'new'.
148 * If 'old' is not VALID, we update it directly,
149 * otherwise we need to replace it
150 */
151 struct cache_head **head;
152 struct cache_head *tmp;
153
154 if (!test_bit(CACHE_VALID, &old->flags)) {
155 write_lock(&detail->hash_lock);
156 if (!test_bit(CACHE_VALID, &old->flags)) {
157 if (test_bit(CACHE_NEGATIVE, &new->flags))
158 set_bit(CACHE_NEGATIVE, &old->flags);
159 else
160 detail->update(old, new);
NeilBrown908329f2009-09-09 16:32:54 +1000161 cache_fresh_locked(old, new->expiry_time);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800162 write_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000163 cache_fresh_unlocked(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800164 return old;
165 }
166 write_unlock(&detail->hash_lock);
167 }
168 /* We need to insert a new entry */
169 tmp = detail->alloc();
170 if (!tmp) {
NeilBrownbaab9352006-03-27 01:15:09 -0800171 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800172 return NULL;
173 }
174 cache_init(tmp);
175 detail->init(tmp, old);
176 head = &detail->hash_table[hash];
177
178 write_lock(&detail->hash_lock);
179 if (test_bit(CACHE_NEGATIVE, &new->flags))
180 set_bit(CACHE_NEGATIVE, &tmp->flags);
181 else
182 detail->update(tmp, new);
183 tmp->next = *head;
184 *head = tmp;
NeilBrownf2d39582006-05-22 22:35:25 -0700185 detail->entries++;
NeilBrown15a5f6b2006-03-27 01:15:02 -0800186 cache_get(tmp);
NeilBrown908329f2009-09-09 16:32:54 +1000187 cache_fresh_locked(tmp, new->expiry_time);
NeilBrownebd0cb12006-03-27 01:15:08 -0800188 cache_fresh_locked(old, 0);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800189 write_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000190 cache_fresh_unlocked(tmp, detail);
191 cache_fresh_unlocked(old, detail);
NeilBrownbaab9352006-03-27 01:15:09 -0800192 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800193 return tmp;
194}
Trond Myklebust24c37672008-12-23 16:30:12 -0500195EXPORT_SYMBOL_GPL(sunrpc_cache_update);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
Trond Myklebustbc74b4f2009-08-09 15:14:29 -0400197static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
198{
199 if (!cd->cache_upcall)
200 return -EINVAL;
201 return cd->cache_upcall(cd, h);
202}
NeilBrown989a19b2009-08-04 15:22:38 +1000203
204static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h)
205{
NeilBrownd202cce2010-02-03 17:31:31 +1100206 if (!test_bit(CACHE_VALID, &h->flags))
NeilBrown989a19b2009-08-04 15:22:38 +1000207 return -EAGAIN;
208 else {
209 /* entry is valid */
210 if (test_bit(CACHE_NEGATIVE, &h->flags))
211 return -ENOENT;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500212 else {
213 /*
214 * In combination with write barrier in
215 * sunrpc_cache_update, ensures that anyone
216 * using the cache entry after this sees the
217 * updated contents:
218 */
219 smp_rmb();
NeilBrown989a19b2009-08-04 15:22:38 +1000220 return 0;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500221 }
NeilBrown989a19b2009-08-04 15:22:38 +1000222 }
223}
J. Bruce Fieldse9dc1222009-08-21 11:27:29 -0400224
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500225static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
226{
227 int rv;
228
229 write_lock(&detail->hash_lock);
230 rv = cache_is_valid(detail, h);
231 if (rv != -EAGAIN) {
232 write_unlock(&detail->hash_lock);
233 return rv;
234 }
235 set_bit(CACHE_NEGATIVE, &h->flags);
236 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY);
237 write_unlock(&detail->hash_lock);
238 cache_fresh_unlocked(h, detail);
239 return -ENOENT;
240}
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242/*
243 * This is the generic cache management routine for all
244 * the authentication caches.
245 * It checks the currency of a cache item and will (later)
246 * initiate an upcall to fill it if needed.
247 *
248 *
249 * Returns 0 if the cache_head can be used, or cache_puts it and returns
NeilBrown989a19b2009-08-04 15:22:38 +1000250 * -EAGAIN if upcall is pending and request has been queued
251 * -ETIMEDOUT if upcall failed or request could not be queue or
252 * upcall completed but item is still invalid (implying that
253 * the cache item has been replaced with a newer one).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 * -ENOENT if cache entry was negative
255 */
256int cache_check(struct cache_detail *detail,
257 struct cache_head *h, struct cache_req *rqstp)
258{
259 int rv;
260 long refresh_age, age;
261
262 /* First decide return status as best we can */
NeilBrown989a19b2009-08-04 15:22:38 +1000263 rv = cache_is_valid(detail, h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265 /* now see if we want to start an upcall */
266 refresh_age = (h->expiry_time - h->last_refresh);
NeilBrownc5b29f82010-08-12 16:55:22 +1000267 age = seconds_since_boot() - h->last_refresh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
269 if (rqstp == NULL) {
270 if (rv == -EAGAIN)
271 rv = -ENOENT;
272 } else if (rv == -EAGAIN || age > refresh_age/2) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500273 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
274 refresh_age, age);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
276 switch (cache_make_upcall(detail, h)) {
277 case -EINVAL:
278 clear_bit(CACHE_PENDING, &h->flags);
NeilBrown5c4d2632009-08-04 15:22:38 +1000279 cache_revisit_request(h);
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500280 rv = try_to_negate_entry(detail, h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 case -EAGAIN:
283 clear_bit(CACHE_PENDING, &h->flags);
284 cache_revisit_request(h);
285 break;
286 }
287 }
288 }
289
NeilBrown989a19b2009-08-04 15:22:38 +1000290 if (rv == -EAGAIN) {
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500291 if (!cache_defer_req(rqstp, h)) {
292 /*
293 * Request was not deferred; handle it as best
294 * we can ourselves:
295 */
NeilBrown989a19b2009-08-04 15:22:38 +1000296 rv = cache_is_valid(detail, h);
297 if (rv == -EAGAIN)
298 rv = -ETIMEDOUT;
299 }
300 }
NeilBrown4013ede2006-03-27 01:15:07 -0800301 if (rv)
NeilBrownbaab9352006-03-27 01:15:09 -0800302 cache_put(h, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 return rv;
304}
Trond Myklebust24c37672008-12-23 16:30:12 -0500305EXPORT_SYMBOL_GPL(cache_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307/*
308 * caches need to be periodically cleaned.
309 * For this we maintain a list of cache_detail and
310 * a current pointer into that list and into the table
311 * for that entry.
312 *
313 * Each time clean_cache is called it finds the next non-empty entry
314 * in the current table and walks the list in that entry
315 * looking for entries that can be removed.
316 *
317 * An entry gets removed if:
318 * - The expiry is before current time
319 * - The last_refresh time is before the flush_time for that cache
320 *
321 * later we might drop old entries with non-NEVER expiry if that table
322 * is getting 'full' for some definition of 'full'
323 *
324 * The question of "how often to scan a table" is an interesting one
325 * and is answered in part by the use of the "nextcheck" field in the
326 * cache_detail.
327 * When a scan of a table begins, the nextcheck field is set to a time
328 * that is well into the future.
329 * While scanning, if an expiry time is found that is earlier than the
330 * current nextcheck time, nextcheck is set to that expiry time.
331 * If the flush_time is ever set to a time earlier than the nextcheck
332 * time, the nextcheck time is then set to that flush_time.
333 *
334 * A table is then only scanned if the current time is at least
335 * the nextcheck time.
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800336 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 */
338
339static LIST_HEAD(cache_list);
340static DEFINE_SPINLOCK(cache_list_lock);
341static struct cache_detail *current_detail;
342static int current_index;
343
David Howells65f27f32006-11-22 14:55:48 +0000344static void do_cache_clean(struct work_struct *work);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +0300345static struct delayed_work cache_cleaner;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
Trond Myklebust5b7a1b92009-08-09 15:14:27 -0400347static void sunrpc_init_cache_detail(struct cache_detail *cd)
J. Bruce Fieldsffe93862007-11-12 17:04:29 -0500348{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 rwlock_init(&cd->hash_lock);
350 INIT_LIST_HEAD(&cd->queue);
351 spin_lock(&cache_list_lock);
352 cd->nextcheck = 0;
353 cd->entries = 0;
354 atomic_set(&cd->readers, 0);
355 cd->last_close = 0;
356 cd->last_warn = -1;
357 list_add(&cd->others, &cache_list);
358 spin_unlock(&cache_list_lock);
359
360 /* start the cleaning process */
David Howells52bad642006-11-22 14:54:01 +0000361 schedule_delayed_work(&cache_cleaner, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362}
363
Trond Myklebust5b7a1b92009-08-09 15:14:27 -0400364static void sunrpc_destroy_cache_detail(struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365{
366 cache_purge(cd);
367 spin_lock(&cache_list_lock);
368 write_lock(&cd->hash_lock);
369 if (cd->entries || atomic_read(&cd->inuse)) {
370 write_unlock(&cd->hash_lock);
371 spin_unlock(&cache_list_lock);
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500372 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 }
374 if (current_detail == cd)
375 current_detail = NULL;
376 list_del_init(&cd->others);
377 write_unlock(&cd->hash_lock);
378 spin_unlock(&cache_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 if (list_empty(&cache_list)) {
380 /* module must be being unloaded so its safe to kill the worker */
Trond Myklebust4011cd92007-08-07 15:33:01 -0400381 cancel_delayed_work_sync(&cache_cleaner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 }
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500383 return;
384out:
385 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386}
387
388/* clean cache tries to find something to clean
389 * and cleans it.
390 * It returns 1 if it cleaned something,
391 * 0 if it didn't find anything this time
392 * -1 if it fell off the end of the list.
393 */
394static int cache_clean(void)
395{
396 int rv = 0;
397 struct list_head *next;
398
399 spin_lock(&cache_list_lock);
400
401 /* find a suitable table if we don't already have one */
402 while (current_detail == NULL ||
403 current_index >= current_detail->hash_size) {
404 if (current_detail)
405 next = current_detail->others.next;
406 else
407 next = cache_list.next;
408 if (next == &cache_list) {
409 current_detail = NULL;
410 spin_unlock(&cache_list_lock);
411 return -1;
412 }
413 current_detail = list_entry(next, struct cache_detail, others);
NeilBrownc5b29f82010-08-12 16:55:22 +1000414 if (current_detail->nextcheck > seconds_since_boot())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 current_index = current_detail->hash_size;
416 else {
417 current_index = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +1000418 current_detail->nextcheck = seconds_since_boot()+30*60;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 }
420 }
421
422 /* find a non-empty bucket in the table */
423 while (current_detail &&
424 current_index < current_detail->hash_size &&
425 current_detail->hash_table[current_index] == NULL)
426 current_index++;
427
428 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800429
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 if (current_detail && current_index < current_detail->hash_size) {
431 struct cache_head *ch, **cp;
432 struct cache_detail *d;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 write_lock(&current_detail->hash_lock);
435
436 /* Ok, now to clean this strand */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 cp = & current_detail->hash_table[current_index];
NeilBrown3af49742010-02-03 17:31:31 +1100439 for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 if (current_detail->nextcheck > ch->expiry_time)
441 current_detail->nextcheck = ch->expiry_time+1;
NeilBrown2f50d8b2010-02-03 17:31:31 +1100442 if (!cache_is_expired(current_detail, ch))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 *cp = ch->next;
446 ch->next = NULL;
447 current_detail->entries--;
448 rv = 1;
NeilBrown3af49742010-02-03 17:31:31 +1100449 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 }
NeilBrown3af49742010-02-03 17:31:31 +1100451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 write_unlock(&current_detail->hash_lock);
453 d = current_detail;
454 if (!ch)
455 current_index ++;
456 spin_unlock(&cache_list_lock);
NeilBrown5c4d2632009-08-04 15:22:38 +1000457 if (ch) {
NeilBrown3af49742010-02-03 17:31:31 +1100458 if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
459 cache_dequeue(current_detail, ch);
NeilBrown5c4d2632009-08-04 15:22:38 +1000460 cache_revisit_request(ch);
NeilBrownbaab9352006-03-27 01:15:09 -0800461 cache_put(ch, d);
NeilBrown5c4d2632009-08-04 15:22:38 +1000462 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 } else
464 spin_unlock(&cache_list_lock);
465
466 return rv;
467}
468
469/*
470 * We want to regularly clean the cache, so we need to schedule some work ...
471 */
David Howells65f27f32006-11-22 14:55:48 +0000472static void do_cache_clean(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473{
474 int delay = 5;
475 if (cache_clean() == -1)
Anton Blanchard6aad89c2009-06-10 12:52:21 -0700476 delay = round_jiffies_relative(30*HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477
478 if (list_empty(&cache_list))
479 delay = 0;
480
481 if (delay)
482 schedule_delayed_work(&cache_cleaner, delay);
483}
484
485
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800486/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 * Clean all caches promptly. This just calls cache_clean
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800488 * repeatedly until we are sure that every cache has had a chance to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 * be fully cleaned
490 */
491void cache_flush(void)
492{
493 while (cache_clean() != -1)
494 cond_resched();
495 while (cache_clean() != -1)
496 cond_resched();
497}
Trond Myklebust24c37672008-12-23 16:30:12 -0500498EXPORT_SYMBOL_GPL(cache_flush);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
500void cache_purge(struct cache_detail *detail)
501{
502 detail->flush_time = LONG_MAX;
NeilBrownc5b29f82010-08-12 16:55:22 +1000503 detail->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 cache_flush();
505 detail->flush_time = 1;
506}
Trond Myklebust24c37672008-12-23 16:30:12 -0500507EXPORT_SYMBOL_GPL(cache_purge);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
509
510/*
511 * Deferral and Revisiting of Requests.
512 *
513 * If a cache lookup finds a pending entry, we
514 * need to defer the request and revisit it later.
515 * All deferred requests are stored in a hash table,
516 * indexed by "struct cache_head *".
517 * As it may be wasteful to store a whole request
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800518 * structure, we allow the request to provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 * deferred form, which must contain a
520 * 'struct cache_deferred_req'
521 * This cache_deferred_req contains a method to allow
522 * it to be revisited when cache info is available
523 */
524
525#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
526#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
527
528#define DFR_MAX 300 /* ??? */
529
530static DEFINE_SPINLOCK(cache_defer_lock);
531static LIST_HEAD(cache_defer_list);
NeilBrown11174492010-08-12 17:04:08 +1000532static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533static int cache_defer_cnt;
534
J. Bruce Fields6610f722010-08-26 13:19:52 -0400535static void __unhash_deferred_req(struct cache_deferred_req *dreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536{
NeilBrown11174492010-08-12 17:04:08 +1000537 hlist_del_init(&dreq->hash);
NeilBrowne33534d2010-10-07 15:29:46 +1100538 if (!list_empty(&dreq->recent)) {
539 list_del_init(&dreq->recent);
540 cache_defer_cnt--;
541 }
J. Bruce Fields6610f722010-08-26 13:19:52 -0400542}
543
544static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
545{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 int hash = DFR_HASH(item);
547
NeilBrowne33534d2010-10-07 15:29:46 +1100548 INIT_LIST_HEAD(&dreq->recent);
NeilBrown11174492010-08-12 17:04:08 +1000549 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
J. Bruce Fields6610f722010-08-26 13:19:52 -0400550}
551
NeilBrowne33534d2010-10-07 15:29:46 +1100552static void setup_deferral(struct cache_deferred_req *dreq,
553 struct cache_head *item,
554 int count_me)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557 dreq->item = item;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 spin_lock(&cache_defer_lock);
560
J. Bruce Fields6610f722010-08-26 13:19:52 -0400561 __hash_deferred_req(dreq, item);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
NeilBrowne33534d2010-10-07 15:29:46 +1100563 if (count_me) {
564 cache_defer_cnt++;
565 list_add(&dreq->recent, &cache_defer_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 }
NeilBrowne33534d2010-10-07 15:29:46 +1100567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 spin_unlock(&cache_defer_lock);
569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
J. Bruce Fields3211af12010-08-26 16:56:23 -0400572struct thread_deferred_req {
573 struct cache_deferred_req handle;
574 struct completion completion;
575};
576
577static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
578{
579 struct thread_deferred_req *dr =
580 container_of(dreq, struct thread_deferred_req, handle);
581 complete(&dr->completion);
582}
583
NeilBrownd29068c42010-10-07 15:29:46 +1100584static void cache_wait_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400585{
586 struct thread_deferred_req sleeper;
587 struct cache_deferred_req *dreq = &sleeper.handle;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400588
589 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
590 dreq->revisit = cache_restart_thread;
591
NeilBrowne33534d2010-10-07 15:29:46 +1100592 setup_deferral(dreq, item, 0);
J. Bruce Fields3211af12010-08-26 16:56:23 -0400593
NeilBrownd29068c42010-10-07 15:29:46 +1100594 if (!test_bit(CACHE_PENDING, &item->flags) ||
NeilBrown277f68d2010-09-22 12:55:06 +1000595 wait_for_completion_interruptible_timeout(
J. Bruce Fields3211af12010-08-26 16:56:23 -0400596 &sleeper.completion, req->thread_wait) <= 0) {
597 /* The completion wasn't completed, so we need
598 * to clean up
599 */
600 spin_lock(&cache_defer_lock);
NeilBrown11174492010-08-12 17:04:08 +1000601 if (!hlist_unhashed(&sleeper.handle.hash)) {
J. Bruce Fields3211af12010-08-26 16:56:23 -0400602 __unhash_deferred_req(&sleeper.handle);
603 spin_unlock(&cache_defer_lock);
604 } else {
605 /* cache_revisit_request already removed
606 * this from the hash table, but hasn't
607 * called ->revisit yet. It will very soon
608 * and we need to wait for it.
609 */
610 spin_unlock(&cache_defer_lock);
611 wait_for_completion(&sleeper.completion);
612 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 }
J. Bruce Fields3211af12010-08-26 16:56:23 -0400614}
615
NeilBrowne33534d2010-10-07 15:29:46 +1100616static void cache_limit_defers(void)
617{
618 /* Make sure we haven't exceed the limit of allowed deferred
619 * requests.
620 */
621 struct cache_deferred_req *discard = NULL;
622
623 if (cache_defer_cnt <= DFR_MAX)
624 return;
625
626 spin_lock(&cache_defer_lock);
627
628 /* Consider removing either the first or the last */
629 if (cache_defer_cnt > DFR_MAX) {
630 if (net_random() & 1)
631 discard = list_entry(cache_defer_list.next,
632 struct cache_deferred_req, recent);
633 else
634 discard = list_entry(cache_defer_list.prev,
635 struct cache_deferred_req, recent);
636 __unhash_deferred_req(discard);
637 }
638 spin_unlock(&cache_defer_lock);
639 if (discard)
640 discard->revisit(discard, 1);
641}
642
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500643/* Return true if and only if a deferred request is queued. */
644static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400645{
646 struct cache_deferred_req *dreq;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400647
J. Bruce Fields3211af12010-08-26 16:56:23 -0400648 if (req->thread_wait) {
NeilBrownd29068c42010-10-07 15:29:46 +1100649 cache_wait_req(req, item);
650 if (!test_bit(CACHE_PENDING, &item->flags))
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500651 return false;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400652 }
653 dreq = req->defer(req);
654 if (dreq == NULL)
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500655 return false;
NeilBrowne33534d2010-10-07 15:29:46 +1100656 setup_deferral(dreq, item, 1);
NeilBrownd29068c42010-10-07 15:29:46 +1100657 if (!test_bit(CACHE_PENDING, &item->flags))
658 /* Bit could have been cleared before we managed to
659 * set up the deferral, so need to revisit just in case
660 */
661 cache_revisit_request(item);
NeilBrowne33534d2010-10-07 15:29:46 +1100662
663 cache_limit_defers();
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500664 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665}
666
667static void cache_revisit_request(struct cache_head *item)
668{
669 struct cache_deferred_req *dreq;
670 struct list_head pending;
NeilBrown11174492010-08-12 17:04:08 +1000671 struct hlist_node *lp, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 int hash = DFR_HASH(item);
673
674 INIT_LIST_HEAD(&pending);
675 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800676
NeilBrown11174492010-08-12 17:04:08 +1000677 hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash)
678 if (dreq->item == item) {
679 __unhash_deferred_req(dreq);
680 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 }
NeilBrown11174492010-08-12 17:04:08 +1000682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 spin_unlock(&cache_defer_lock);
684
685 while (!list_empty(&pending)) {
686 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
687 list_del_init(&dreq->recent);
688 dreq->revisit(dreq, 0);
689 }
690}
691
692void cache_clean_deferred(void *owner)
693{
694 struct cache_deferred_req *dreq, *tmp;
695 struct list_head pending;
696
697
698 INIT_LIST_HEAD(&pending);
699 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
702 if (dreq->owner == owner) {
J. Bruce Fields6610f722010-08-26 13:19:52 -0400703 __unhash_deferred_req(dreq);
NeilBrowne95dffa2010-09-22 12:55:06 +1000704 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 }
706 }
707 spin_unlock(&cache_defer_lock);
708
709 while (!list_empty(&pending)) {
710 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
711 list_del_init(&dreq->recent);
712 dreq->revisit(dreq, 1);
713 }
714}
715
716/*
717 * communicate with user-space
718 *
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500719 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
720 * On read, you get a full request, or block.
721 * On write, an update request is processed.
722 * Poll works if anything to read, and always allows write.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800724 * Implemented by linked list of requests. Each open file has
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500725 * a ->private that also exists in this list. New requests are added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 * to the end and may wakeup and preceding readers.
727 * New readers are added to the head. If, on read, an item is found with
728 * CACHE_UPCALLING clear, we free it from the list.
729 *
730 */
731
732static DEFINE_SPINLOCK(queue_lock);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800733static DEFINE_MUTEX(queue_io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
735struct cache_queue {
736 struct list_head list;
737 int reader; /* if 0, then request */
738};
739struct cache_request {
740 struct cache_queue q;
741 struct cache_head *item;
742 char * buf;
743 int len;
744 int readers;
745};
746struct cache_reader {
747 struct cache_queue q;
748 int offset; /* if non-0, we have a refcnt on next request */
749};
750
Trond Myklebust173912a2009-08-09 15:14:29 -0400751static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
752 loff_t *ppos, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753{
754 struct cache_reader *rp = filp->private_data;
755 struct cache_request *rq;
Trond Myklebustda770052009-08-09 15:14:28 -0400756 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 int err;
758
759 if (count == 0)
760 return 0;
761
Trond Myklebustda770052009-08-09 15:14:28 -0400762 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 * readers on this file */
764 again:
765 spin_lock(&queue_lock);
766 /* need to find next request */
767 while (rp->q.list.next != &cd->queue &&
768 list_entry(rp->q.list.next, struct cache_queue, list)
769 ->reader) {
770 struct list_head *next = rp->q.list.next;
771 list_move(&rp->q.list, next);
772 }
773 if (rp->q.list.next == &cd->queue) {
774 spin_unlock(&queue_lock);
Trond Myklebustda770052009-08-09 15:14:28 -0400775 mutex_unlock(&inode->i_mutex);
Kris Katterjohn09a62662006-01-08 22:24:28 -0800776 BUG_ON(rp->offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 return 0;
778 }
779 rq = container_of(rp->q.list.next, struct cache_request, q.list);
Kris Katterjohn09a62662006-01-08 22:24:28 -0800780 BUG_ON(rq->q.reader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 if (rp->offset == 0)
782 rq->readers++;
783 spin_unlock(&queue_lock);
784
785 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
786 err = -EAGAIN;
787 spin_lock(&queue_lock);
788 list_move(&rp->q.list, &rq->q.list);
789 spin_unlock(&queue_lock);
790 } else {
791 if (rp->offset + count > rq->len)
792 count = rq->len - rp->offset;
793 err = -EFAULT;
794 if (copy_to_user(buf, rq->buf + rp->offset, count))
795 goto out;
796 rp->offset += count;
797 if (rp->offset >= rq->len) {
798 rp->offset = 0;
799 spin_lock(&queue_lock);
800 list_move(&rp->q.list, &rq->q.list);
801 spin_unlock(&queue_lock);
802 }
803 err = 0;
804 }
805 out:
806 if (rp->offset == 0) {
807 /* need to release rq */
808 spin_lock(&queue_lock);
809 rq->readers--;
810 if (rq->readers == 0 &&
811 !test_bit(CACHE_PENDING, &rq->item->flags)) {
812 list_del(&rq->q.list);
813 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800814 cache_put(rq->item, cd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 kfree(rq->buf);
816 kfree(rq);
817 } else
818 spin_unlock(&queue_lock);
819 }
820 if (err == -EAGAIN)
821 goto again;
Trond Myklebustda770052009-08-09 15:14:28 -0400822 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 return err ? err : count;
824}
825
Trond Myklebustda770052009-08-09 15:14:28 -0400826static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
827 size_t count, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828{
Trond Myklebustda770052009-08-09 15:14:28 -0400829 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
Trond Myklebustda770052009-08-09 15:14:28 -0400831 if (copy_from_user(kaddr, buf, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 return -EFAULT;
Trond Myklebustda770052009-08-09 15:14:28 -0400833 kaddr[count] = '\0';
834 ret = cd->cache_parse(cd, kaddr, count);
835 if (!ret)
836 ret = count;
837 return ret;
838}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839
Trond Myklebustda770052009-08-09 15:14:28 -0400840static ssize_t cache_slow_downcall(const char __user *buf,
841 size_t count, struct cache_detail *cd)
842{
843 static char write_buf[8192]; /* protected by queue_io_mutex */
844 ssize_t ret = -EINVAL;
845
846 if (count >= sizeof(write_buf))
847 goto out;
848 mutex_lock(&queue_io_mutex);
849 ret = cache_do_downcall(write_buf, buf, count, cd);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800850 mutex_unlock(&queue_io_mutex);
Trond Myklebustda770052009-08-09 15:14:28 -0400851out:
852 return ret;
853}
854
855static ssize_t cache_downcall(struct address_space *mapping,
856 const char __user *buf,
857 size_t count, struct cache_detail *cd)
858{
859 struct page *page;
860 char *kaddr;
861 ssize_t ret = -ENOMEM;
862
863 if (count >= PAGE_CACHE_SIZE)
864 goto out_slow;
865
866 page = find_or_create_page(mapping, 0, GFP_KERNEL);
867 if (!page)
868 goto out_slow;
869
870 kaddr = kmap(page);
871 ret = cache_do_downcall(kaddr, buf, count, cd);
872 kunmap(page);
873 unlock_page(page);
874 page_cache_release(page);
875 return ret;
876out_slow:
877 return cache_slow_downcall(buf, count, cd);
878}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
Trond Myklebust173912a2009-08-09 15:14:29 -0400880static ssize_t cache_write(struct file *filp, const char __user *buf,
881 size_t count, loff_t *ppos,
882 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883{
Trond Myklebustda770052009-08-09 15:14:28 -0400884 struct address_space *mapping = filp->f_mapping;
885 struct inode *inode = filp->f_path.dentry->d_inode;
Trond Myklebustda770052009-08-09 15:14:28 -0400886 ssize_t ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
Trond Myklebustda770052009-08-09 15:14:28 -0400888 if (!cd->cache_parse)
889 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890
Trond Myklebustda770052009-08-09 15:14:28 -0400891 mutex_lock(&inode->i_mutex);
892 ret = cache_downcall(mapping, buf, count, cd);
893 mutex_unlock(&inode->i_mutex);
894out:
895 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896}
897
898static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
899
Trond Myklebust173912a2009-08-09 15:14:29 -0400900static unsigned int cache_poll(struct file *filp, poll_table *wait,
901 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902{
903 unsigned int mask;
904 struct cache_reader *rp = filp->private_data;
905 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
907 poll_wait(filp, &queue_wait, wait);
908
909 /* alway allow write */
910 mask = POLL_OUT | POLLWRNORM;
911
912 if (!rp)
913 return mask;
914
915 spin_lock(&queue_lock);
916
917 for (cq= &rp->q; &cq->list != &cd->queue;
918 cq = list_entry(cq->list.next, struct cache_queue, list))
919 if (!cq->reader) {
920 mask |= POLLIN | POLLRDNORM;
921 break;
922 }
923 spin_unlock(&queue_lock);
924 return mask;
925}
926
Trond Myklebust173912a2009-08-09 15:14:29 -0400927static int cache_ioctl(struct inode *ino, struct file *filp,
928 unsigned int cmd, unsigned long arg,
929 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930{
931 int len = 0;
932 struct cache_reader *rp = filp->private_data;
933 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
935 if (cmd != FIONREAD || !rp)
936 return -EINVAL;
937
938 spin_lock(&queue_lock);
939
940 /* only find the length remaining in current request,
941 * or the length of the next request
942 */
943 for (cq= &rp->q; &cq->list != &cd->queue;
944 cq = list_entry(cq->list.next, struct cache_queue, list))
945 if (!cq->reader) {
946 struct cache_request *cr =
947 container_of(cq, struct cache_request, q);
948 len = cr->len - rp->offset;
949 break;
950 }
951 spin_unlock(&queue_lock);
952
953 return put_user(len, (int __user *)arg);
954}
955
Trond Myklebust173912a2009-08-09 15:14:29 -0400956static int cache_open(struct inode *inode, struct file *filp,
957 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958{
959 struct cache_reader *rp = NULL;
960
Trond Myklebustf7e86ab2009-08-19 18:13:00 -0400961 if (!cd || !try_module_get(cd->owner))
962 return -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 nonseekable_open(inode, filp);
964 if (filp->f_mode & FMODE_READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
966 if (!rp)
967 return -ENOMEM;
968 rp->offset = 0;
969 rp->q.reader = 1;
970 atomic_inc(&cd->readers);
971 spin_lock(&queue_lock);
972 list_add(&rp->q.list, &cd->queue);
973 spin_unlock(&queue_lock);
974 }
975 filp->private_data = rp;
976 return 0;
977}
978
Trond Myklebust173912a2009-08-09 15:14:29 -0400979static int cache_release(struct inode *inode, struct file *filp,
980 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981{
982 struct cache_reader *rp = filp->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983
984 if (rp) {
985 spin_lock(&queue_lock);
986 if (rp->offset) {
987 struct cache_queue *cq;
988 for (cq= &rp->q; &cq->list != &cd->queue;
989 cq = list_entry(cq->list.next, struct cache_queue, list))
990 if (!cq->reader) {
991 container_of(cq, struct cache_request, q)
992 ->readers--;
993 break;
994 }
995 rp->offset = 0;
996 }
997 list_del(&rp->q.list);
998 spin_unlock(&queue_lock);
999
1000 filp->private_data = NULL;
1001 kfree(rp);
1002
NeilBrownc5b29f82010-08-12 16:55:22 +10001003 cd->last_close = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 atomic_dec(&cd->readers);
1005 }
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001006 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 return 0;
1008}
1009
1010
1011
NeilBrownf866a812009-08-04 15:22:38 +10001012static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013{
1014 struct cache_queue *cq;
1015 spin_lock(&queue_lock);
1016 list_for_each_entry(cq, &detail->queue, list)
1017 if (!cq->reader) {
1018 struct cache_request *cr = container_of(cq, struct cache_request, q);
1019 if (cr->item != ch)
1020 continue;
1021 if (cr->readers != 0)
NeilBrown4013ede2006-03-27 01:15:07 -08001022 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 list_del(&cr->q.list);
1024 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -08001025 cache_put(cr->item, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 kfree(cr->buf);
1027 kfree(cr);
1028 return;
1029 }
1030 spin_unlock(&queue_lock);
1031}
1032
1033/*
1034 * Support routines for text-based upcalls.
1035 * Fields are separated by spaces.
1036 * Fields are either mangled to quote space tab newline slosh with slosh
1037 * or a hexified with a leading \x
1038 * Record is terminated with newline.
1039 *
1040 */
1041
1042void qword_add(char **bpp, int *lp, char *str)
1043{
1044 char *bp = *bpp;
1045 int len = *lp;
1046 char c;
1047
1048 if (len < 0) return;
1049
1050 while ((c=*str++) && len)
1051 switch(c) {
1052 case ' ':
1053 case '\t':
1054 case '\n':
1055 case '\\':
1056 if (len >= 4) {
1057 *bp++ = '\\';
1058 *bp++ = '0' + ((c & 0300)>>6);
1059 *bp++ = '0' + ((c & 0070)>>3);
1060 *bp++ = '0' + ((c & 0007)>>0);
1061 }
1062 len -= 4;
1063 break;
1064 default:
1065 *bp++ = c;
1066 len--;
1067 }
1068 if (c || len <1) len = -1;
1069 else {
1070 *bp++ = ' ';
1071 len--;
1072 }
1073 *bpp = bp;
1074 *lp = len;
1075}
Trond Myklebust24c37672008-12-23 16:30:12 -05001076EXPORT_SYMBOL_GPL(qword_add);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077
1078void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1079{
1080 char *bp = *bpp;
1081 int len = *lp;
1082
1083 if (len < 0) return;
1084
1085 if (len > 2) {
1086 *bp++ = '\\';
1087 *bp++ = 'x';
1088 len -= 2;
1089 while (blen && len >= 2) {
1090 unsigned char c = *buf++;
1091 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
1092 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
1093 len -= 2;
1094 blen--;
1095 }
1096 }
1097 if (blen || len<1) len = -1;
1098 else {
1099 *bp++ = ' ';
1100 len--;
1101 }
1102 *bpp = bp;
1103 *lp = len;
1104}
Trond Myklebust24c37672008-12-23 16:30:12 -05001105EXPORT_SYMBOL_GPL(qword_addhex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106
1107static void warn_no_listener(struct cache_detail *detail)
1108{
1109 if (detail->last_warn != detail->last_close) {
1110 detail->last_warn = detail->last_close;
1111 if (detail->warn_no_listener)
Trond Myklebust2da8ca22009-08-09 15:14:26 -04001112 detail->warn_no_listener(detail, detail->last_close != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 }
1114}
1115
J. Bruce Fields06497522010-09-19 22:55:06 -04001116static bool cache_listeners_exist(struct cache_detail *detail)
1117{
1118 if (atomic_read(&detail->readers))
1119 return true;
1120 if (detail->last_close == 0)
1121 /* This cache was never opened */
1122 return false;
1123 if (detail->last_close < seconds_since_boot() - 30)
1124 /*
1125 * We allow for the possibility that someone might
1126 * restart a userspace daemon without restarting the
1127 * server; but after 30 seconds, we give up.
1128 */
1129 return false;
1130 return true;
1131}
1132
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133/*
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001134 * register an upcall request to user-space and queue it up for read() by the
1135 * upcall daemon.
1136 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 * Each request is at most one page long.
1138 */
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001139int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
1140 void (*cache_request)(struct cache_detail *,
1141 struct cache_head *,
1142 char **,
1143 int *))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144{
1145
1146 char *buf;
1147 struct cache_request *crq;
1148 char *bp;
1149 int len;
1150
J. Bruce Fields06497522010-09-19 22:55:06 -04001151 if (!cache_listeners_exist(detail)) {
1152 warn_no_listener(detail);
1153 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 }
1155
1156 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1157 if (!buf)
1158 return -EAGAIN;
1159
1160 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1161 if (!crq) {
1162 kfree(buf);
1163 return -EAGAIN;
1164 }
1165
1166 bp = buf; len = PAGE_SIZE;
1167
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001168 cache_request(detail, h, &bp, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169
1170 if (len < 0) {
1171 kfree(buf);
1172 kfree(crq);
1173 return -EAGAIN;
1174 }
1175 crq->q.reader = 0;
1176 crq->item = cache_get(h);
1177 crq->buf = buf;
1178 crq->len = PAGE_SIZE - len;
1179 crq->readers = 0;
1180 spin_lock(&queue_lock);
1181 list_add_tail(&crq->q.list, &detail->queue);
1182 spin_unlock(&queue_lock);
1183 wake_up(&queue_wait);
1184 return 0;
1185}
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001186EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187
1188/*
1189 * parse a message from user-space and pass it
1190 * to an appropriate cache
1191 * Messages are, like requests, separated into fields by
1192 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1193 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001194 * Message is
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 * reply cachename expiry key ... content....
1196 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001197 * key and content are both parsed by cache
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 */
1199
1200#define isodigit(c) (isdigit(c) && c <= '7')
1201int qword_get(char **bpp, char *dest, int bufsize)
1202{
1203 /* return bytes copied, or -1 on error */
1204 char *bp = *bpp;
1205 int len = 0;
1206
1207 while (*bp == ' ') bp++;
1208
1209 if (bp[0] == '\\' && bp[1] == 'x') {
1210 /* HEX STRING */
1211 bp += 2;
Andy Shevchenkoe7f483e2010-09-21 09:40:25 +03001212 while (len < bufsize) {
1213 int h, l;
1214
1215 h = hex_to_bin(bp[0]);
1216 if (h < 0)
1217 break;
1218
1219 l = hex_to_bin(bp[1]);
1220 if (l < 0)
1221 break;
1222
1223 *dest++ = (h << 4) | l;
1224 bp += 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 len++;
1226 }
1227 } else {
1228 /* text with \nnn octal quoting */
1229 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1230 if (*bp == '\\' &&
1231 isodigit(bp[1]) && (bp[1] <= '3') &&
1232 isodigit(bp[2]) &&
1233 isodigit(bp[3])) {
1234 int byte = (*++bp -'0');
1235 bp++;
1236 byte = (byte << 3) | (*bp++ - '0');
1237 byte = (byte << 3) | (*bp++ - '0');
1238 *dest++ = byte;
1239 len++;
1240 } else {
1241 *dest++ = *bp++;
1242 len++;
1243 }
1244 }
1245 }
1246
1247 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1248 return -1;
1249 while (*bp == ' ') bp++;
1250 *bpp = bp;
1251 *dest = '\0';
1252 return len;
1253}
Trond Myklebust24c37672008-12-23 16:30:12 -05001254EXPORT_SYMBOL_GPL(qword_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255
1256
1257/*
1258 * support /proc/sunrpc/cache/$CACHENAME/content
1259 * as a seqfile.
1260 * We call ->cache_show passing NULL for the item to
1261 * get a header, then pass each real item in the cache
1262 */
1263
1264struct handle {
1265 struct cache_detail *cd;
1266};
1267
1268static void *c_start(struct seq_file *m, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001269 __acquires(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270{
1271 loff_t n = *pos;
1272 unsigned hash, entry;
1273 struct cache_head *ch;
1274 struct cache_detail *cd = ((struct handle*)m->private)->cd;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001275
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276
1277 read_lock(&cd->hash_lock);
1278 if (!n--)
1279 return SEQ_START_TOKEN;
1280 hash = n >> 32;
1281 entry = n & ((1LL<<32) - 1);
1282
1283 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1284 if (!entry--)
1285 return ch;
1286 n &= ~((1LL<<32) - 1);
1287 do {
1288 hash++;
1289 n += 1LL<<32;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001290 } while(hash < cd->hash_size &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 cd->hash_table[hash]==NULL);
1292 if (hash >= cd->hash_size)
1293 return NULL;
1294 *pos = n+1;
1295 return cd->hash_table[hash];
1296}
1297
1298static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1299{
1300 struct cache_head *ch = p;
1301 int hash = (*pos >> 32);
1302 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1303
1304 if (p == SEQ_START_TOKEN)
1305 hash = 0;
1306 else if (ch->next == NULL) {
1307 hash++;
1308 *pos += 1LL<<32;
1309 } else {
1310 ++*pos;
1311 return ch->next;
1312 }
1313 *pos &= ~((1LL<<32) - 1);
1314 while (hash < cd->hash_size &&
1315 cd->hash_table[hash] == NULL) {
1316 hash++;
1317 *pos += 1LL<<32;
1318 }
1319 if (hash >= cd->hash_size)
1320 return NULL;
1321 ++*pos;
1322 return cd->hash_table[hash];
1323}
1324
1325static void c_stop(struct seq_file *m, void *p)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001326 __releases(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327{
1328 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1329 read_unlock(&cd->hash_lock);
1330}
1331
1332static int c_show(struct seq_file *m, void *p)
1333{
1334 struct cache_head *cp = p;
1335 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1336
1337 if (p == SEQ_START_TOKEN)
1338 return cd->cache_show(m, cd, NULL);
1339
1340 ifdebug(CACHE)
NeilBrown4013ede2006-03-27 01:15:07 -08001341 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
NeilBrownc5b29f82010-08-12 16:55:22 +10001342 convert_to_wallclock(cp->expiry_time),
1343 atomic_read(&cp->ref.refcount), cp->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 cache_get(cp);
1345 if (cache_check(cd, cp, NULL))
1346 /* cache_check does a cache_put on failure */
1347 seq_printf(m, "# ");
1348 else
1349 cache_put(cp, cd);
1350
1351 return cd->cache_show(m, cd, cp);
1352}
1353
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001354static const struct seq_operations cache_content_op = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 .start = c_start,
1356 .next = c_next,
1357 .stop = c_stop,
1358 .show = c_show,
1359};
1360
Trond Myklebust173912a2009-08-09 15:14:29 -04001361static int content_open(struct inode *inode, struct file *file,
1362 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 struct handle *han;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001366 if (!cd || !try_module_get(cd->owner))
1367 return -EACCES;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001368 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
Li Zefana5990ea2010-03-11 14:08:10 -08001369 if (han == NULL) {
1370 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 return -ENOMEM;
Li Zefana5990ea2010-03-11 14:08:10 -08001372 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373
1374 han->cd = cd;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001375 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001378static int content_release(struct inode *inode, struct file *file,
1379 struct cache_detail *cd)
1380{
1381 int ret = seq_release_private(inode, file);
1382 module_put(cd->owner);
1383 return ret;
1384}
1385
1386static int open_flush(struct inode *inode, struct file *file,
1387 struct cache_detail *cd)
1388{
1389 if (!cd || !try_module_get(cd->owner))
1390 return -EACCES;
1391 return nonseekable_open(inode, file);
1392}
1393
1394static int release_flush(struct inode *inode, struct file *file,
1395 struct cache_detail *cd)
1396{
1397 module_put(cd->owner);
1398 return 0;
1399}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400
1401static ssize_t read_flush(struct file *file, char __user *buf,
Trond Myklebust173912a2009-08-09 15:14:29 -04001402 size_t count, loff_t *ppos,
1403 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405 char tbuf[20];
1406 unsigned long p = *ppos;
Chuck Lever01b29692007-10-26 13:31:20 -04001407 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408
NeilBrownc5b29f82010-08-12 16:55:22 +10001409 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 len = strlen(tbuf);
1411 if (p >= len)
1412 return 0;
1413 len -= p;
Chuck Lever01b29692007-10-26 13:31:20 -04001414 if (len > count)
1415 len = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 if (copy_to_user(buf, (void*)(tbuf+p), len))
Chuck Lever01b29692007-10-26 13:31:20 -04001417 return -EFAULT;
1418 *ppos += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 return len;
1420}
1421
Trond Myklebust173912a2009-08-09 15:14:29 -04001422static ssize_t write_flush(struct file *file, const char __user *buf,
1423 size_t count, loff_t *ppos,
1424 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001426 char tbuf[20];
NeilBrownc5b29f82010-08-12 16:55:22 +10001427 char *bp, *ep;
1428
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 if (*ppos || count > sizeof(tbuf)-1)
1430 return -EINVAL;
1431 if (copy_from_user(tbuf, buf, count))
1432 return -EFAULT;
1433 tbuf[count] = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +10001434 simple_strtoul(tbuf, &ep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435 if (*ep && *ep != '\n')
1436 return -EINVAL;
1437
NeilBrownc5b29f82010-08-12 16:55:22 +10001438 bp = tbuf;
1439 cd->flush_time = get_expiry(&bp);
1440 cd->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 cache_flush();
1442
1443 *ppos += count;
1444 return count;
1445}
1446
Trond Myklebust173912a2009-08-09 15:14:29 -04001447static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1448 size_t count, loff_t *ppos)
1449{
1450 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1451
1452 return cache_read(filp, buf, count, ppos, cd);
1453}
1454
1455static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1456 size_t count, loff_t *ppos)
1457{
1458 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1459
1460 return cache_write(filp, buf, count, ppos, cd);
1461}
1462
1463static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1464{
1465 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1466
1467 return cache_poll(filp, wait, cd);
1468}
1469
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001470static long cache_ioctl_procfs(struct file *filp,
1471 unsigned int cmd, unsigned long arg)
Trond Myklebust173912a2009-08-09 15:14:29 -04001472{
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001473 struct inode *inode = filp->f_path.dentry->d_inode;
Trond Myklebust173912a2009-08-09 15:14:29 -04001474 struct cache_detail *cd = PDE(inode)->data;
1475
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001476 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001477}
1478
1479static int cache_open_procfs(struct inode *inode, struct file *filp)
1480{
1481 struct cache_detail *cd = PDE(inode)->data;
1482
1483 return cache_open(inode, filp, cd);
1484}
1485
1486static int cache_release_procfs(struct inode *inode, struct file *filp)
1487{
1488 struct cache_detail *cd = PDE(inode)->data;
1489
1490 return cache_release(inode, filp, cd);
1491}
1492
1493static const struct file_operations cache_file_operations_procfs = {
1494 .owner = THIS_MODULE,
1495 .llseek = no_llseek,
1496 .read = cache_read_procfs,
1497 .write = cache_write_procfs,
1498 .poll = cache_poll_procfs,
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001499 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
Trond Myklebust173912a2009-08-09 15:14:29 -04001500 .open = cache_open_procfs,
1501 .release = cache_release_procfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502};
Trond Myklebust173912a2009-08-09 15:14:29 -04001503
1504static int content_open_procfs(struct inode *inode, struct file *filp)
1505{
1506 struct cache_detail *cd = PDE(inode)->data;
1507
1508 return content_open(inode, filp, cd);
1509}
1510
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001511static int content_release_procfs(struct inode *inode, struct file *filp)
1512{
1513 struct cache_detail *cd = PDE(inode)->data;
1514
1515 return content_release(inode, filp, cd);
1516}
1517
Trond Myklebust173912a2009-08-09 15:14:29 -04001518static const struct file_operations content_file_operations_procfs = {
1519 .open = content_open_procfs,
1520 .read = seq_read,
1521 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001522 .release = content_release_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001523};
1524
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001525static int open_flush_procfs(struct inode *inode, struct file *filp)
1526{
1527 struct cache_detail *cd = PDE(inode)->data;
1528
1529 return open_flush(inode, filp, cd);
1530}
1531
1532static int release_flush_procfs(struct inode *inode, struct file *filp)
1533{
1534 struct cache_detail *cd = PDE(inode)->data;
1535
1536 return release_flush(inode, filp, cd);
1537}
1538
Trond Myklebust173912a2009-08-09 15:14:29 -04001539static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1540 size_t count, loff_t *ppos)
1541{
1542 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1543
1544 return read_flush(filp, buf, count, ppos, cd);
1545}
1546
1547static ssize_t write_flush_procfs(struct file *filp,
1548 const char __user *buf,
1549 size_t count, loff_t *ppos)
1550{
1551 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1552
1553 return write_flush(filp, buf, count, ppos, cd);
1554}
1555
1556static const struct file_operations cache_flush_operations_procfs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001557 .open = open_flush_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001558 .read = read_flush_procfs,
1559 .write = write_flush_procfs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001560 .release = release_flush_procfs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001561 .llseek = no_llseek,
Trond Myklebust173912a2009-08-09 15:14:29 -04001562};
1563
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001564static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001565{
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001566 struct sunrpc_net *sn;
1567
Trond Myklebust173912a2009-08-09 15:14:29 -04001568 if (cd->u.procfs.proc_ent == NULL)
1569 return;
1570 if (cd->u.procfs.flush_ent)
1571 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1572 if (cd->u.procfs.channel_ent)
1573 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1574 if (cd->u.procfs.content_ent)
1575 remove_proc_entry("content", cd->u.procfs.proc_ent);
1576 cd->u.procfs.proc_ent = NULL;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001577 sn = net_generic(net, sunrpc_net_id);
1578 remove_proc_entry(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001579}
1580
1581#ifdef CONFIG_PROC_FS
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001582static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001583{
1584 struct proc_dir_entry *p;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001585 struct sunrpc_net *sn;
Trond Myklebust173912a2009-08-09 15:14:29 -04001586
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001587 sn = net_generic(net, sunrpc_net_id);
1588 cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001589 if (cd->u.procfs.proc_ent == NULL)
1590 goto out_nomem;
1591 cd->u.procfs.channel_ent = NULL;
1592 cd->u.procfs.content_ent = NULL;
1593
1594 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1595 cd->u.procfs.proc_ent,
1596 &cache_flush_operations_procfs, cd);
1597 cd->u.procfs.flush_ent = p;
1598 if (p == NULL)
1599 goto out_nomem;
1600
1601 if (cd->cache_upcall || cd->cache_parse) {
1602 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1603 cd->u.procfs.proc_ent,
1604 &cache_file_operations_procfs, cd);
1605 cd->u.procfs.channel_ent = p;
1606 if (p == NULL)
1607 goto out_nomem;
1608 }
1609 if (cd->cache_show) {
1610 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
1611 cd->u.procfs.proc_ent,
1612 &content_file_operations_procfs, cd);
1613 cd->u.procfs.content_ent = p;
1614 if (p == NULL)
1615 goto out_nomem;
1616 }
1617 return 0;
1618out_nomem:
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001619 remove_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001620 return -ENOMEM;
1621}
1622#else /* CONFIG_PROC_FS */
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001623static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001624{
1625 return 0;
1626}
1627#endif
1628
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001629void __init cache_initialize(void)
1630{
1631 INIT_DELAYED_WORK_DEFERRABLE(&cache_cleaner, do_cache_clean);
1632}
1633
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001634int cache_register_net(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001635{
1636 int ret;
1637
1638 sunrpc_init_cache_detail(cd);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001639 ret = create_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001640 if (ret)
1641 sunrpc_destroy_cache_detail(cd);
1642 return ret;
1643}
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001644
1645int cache_register(struct cache_detail *cd)
1646{
1647 return cache_register_net(cd, &init_net);
1648}
Trond Myklebust173912a2009-08-09 15:14:29 -04001649EXPORT_SYMBOL_GPL(cache_register);
1650
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001651void cache_unregister_net(struct cache_detail *cd, struct net *net)
1652{
1653 remove_cache_proc_entries(cd, net);
1654 sunrpc_destroy_cache_detail(cd);
1655}
1656
Trond Myklebust173912a2009-08-09 15:14:29 -04001657void cache_unregister(struct cache_detail *cd)
1658{
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001659 cache_unregister_net(cd, &init_net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001660}
1661EXPORT_SYMBOL_GPL(cache_unregister);
Trond Myklebust8854e822009-08-09 15:14:30 -04001662
1663static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1664 size_t count, loff_t *ppos)
1665{
1666 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1667
1668 return cache_read(filp, buf, count, ppos, cd);
1669}
1670
1671static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1672 size_t count, loff_t *ppos)
1673{
1674 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1675
1676 return cache_write(filp, buf, count, ppos, cd);
1677}
1678
1679static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1680{
1681 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1682
1683 return cache_poll(filp, wait, cd);
1684}
1685
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001686static long cache_ioctl_pipefs(struct file *filp,
Trond Myklebust8854e822009-08-09 15:14:30 -04001687 unsigned int cmd, unsigned long arg)
1688{
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001689 struct inode *inode = filp->f_dentry->d_inode;
Trond Myklebust8854e822009-08-09 15:14:30 -04001690 struct cache_detail *cd = RPC_I(inode)->private;
1691
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001692 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust8854e822009-08-09 15:14:30 -04001693}
1694
1695static int cache_open_pipefs(struct inode *inode, struct file *filp)
1696{
1697 struct cache_detail *cd = RPC_I(inode)->private;
1698
1699 return cache_open(inode, filp, cd);
1700}
1701
1702static int cache_release_pipefs(struct inode *inode, struct file *filp)
1703{
1704 struct cache_detail *cd = RPC_I(inode)->private;
1705
1706 return cache_release(inode, filp, cd);
1707}
1708
1709const struct file_operations cache_file_operations_pipefs = {
1710 .owner = THIS_MODULE,
1711 .llseek = no_llseek,
1712 .read = cache_read_pipefs,
1713 .write = cache_write_pipefs,
1714 .poll = cache_poll_pipefs,
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001715 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
Trond Myklebust8854e822009-08-09 15:14:30 -04001716 .open = cache_open_pipefs,
1717 .release = cache_release_pipefs,
1718};
1719
1720static int content_open_pipefs(struct inode *inode, struct file *filp)
1721{
1722 struct cache_detail *cd = RPC_I(inode)->private;
1723
1724 return content_open(inode, filp, cd);
1725}
1726
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001727static int content_release_pipefs(struct inode *inode, struct file *filp)
1728{
1729 struct cache_detail *cd = RPC_I(inode)->private;
1730
1731 return content_release(inode, filp, cd);
1732}
1733
Trond Myklebust8854e822009-08-09 15:14:30 -04001734const struct file_operations content_file_operations_pipefs = {
1735 .open = content_open_pipefs,
1736 .read = seq_read,
1737 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001738 .release = content_release_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001739};
1740
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001741static int open_flush_pipefs(struct inode *inode, struct file *filp)
1742{
1743 struct cache_detail *cd = RPC_I(inode)->private;
1744
1745 return open_flush(inode, filp, cd);
1746}
1747
1748static int release_flush_pipefs(struct inode *inode, struct file *filp)
1749{
1750 struct cache_detail *cd = RPC_I(inode)->private;
1751
1752 return release_flush(inode, filp, cd);
1753}
1754
Trond Myklebust8854e822009-08-09 15:14:30 -04001755static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1756 size_t count, loff_t *ppos)
1757{
1758 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1759
1760 return read_flush(filp, buf, count, ppos, cd);
1761}
1762
1763static ssize_t write_flush_pipefs(struct file *filp,
1764 const char __user *buf,
1765 size_t count, loff_t *ppos)
1766{
1767 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1768
1769 return write_flush(filp, buf, count, ppos, cd);
1770}
1771
1772const struct file_operations cache_flush_operations_pipefs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001773 .open = open_flush_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001774 .read = read_flush_pipefs,
1775 .write = write_flush_pipefs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001776 .release = release_flush_pipefs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001777 .llseek = no_llseek,
Trond Myklebust8854e822009-08-09 15:14:30 -04001778};
1779
1780int sunrpc_cache_register_pipefs(struct dentry *parent,
1781 const char *name, mode_t umode,
1782 struct cache_detail *cd)
1783{
1784 struct qstr q;
1785 struct dentry *dir;
1786 int ret = 0;
1787
1788 sunrpc_init_cache_detail(cd);
1789 q.name = name;
1790 q.len = strlen(name);
1791 q.hash = full_name_hash(q.name, q.len);
1792 dir = rpc_create_cache_dir(parent, &q, umode, cd);
1793 if (!IS_ERR(dir))
1794 cd->u.pipefs.dir = dir;
1795 else {
1796 sunrpc_destroy_cache_detail(cd);
1797 ret = PTR_ERR(dir);
1798 }
1799 return ret;
1800}
1801EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1802
1803void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1804{
1805 rpc_remove_cache_dir(cd->u.pipefs.dir);
1806 cd->u.pipefs.dir = NULL;
1807 sunrpc_destroy_cache_detail(cd);
1808}
1809EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
1810