blob: 2a68bb3db772a4d6001716e28af4385bb9c066bb [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
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300347void 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}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300363EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300365void sunrpc_destroy_cache_detail(struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366{
367 cache_purge(cd);
368 spin_lock(&cache_list_lock);
369 write_lock(&cd->hash_lock);
370 if (cd->entries || atomic_read(&cd->inuse)) {
371 write_unlock(&cd->hash_lock);
372 spin_unlock(&cache_list_lock);
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500373 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 }
375 if (current_detail == cd)
376 current_detail = NULL;
377 list_del_init(&cd->others);
378 write_unlock(&cd->hash_lock);
379 spin_unlock(&cache_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 if (list_empty(&cache_list)) {
381 /* module must be being unloaded so its safe to kill the worker */
Trond Myklebust4011cd92007-08-07 15:33:01 -0400382 cancel_delayed_work_sync(&cache_cleaner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 }
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500384 return;
385out:
386 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300388EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
390/* clean cache tries to find something to clean
391 * and cleans it.
392 * It returns 1 if it cleaned something,
393 * 0 if it didn't find anything this time
394 * -1 if it fell off the end of the list.
395 */
396static int cache_clean(void)
397{
398 int rv = 0;
399 struct list_head *next;
400
401 spin_lock(&cache_list_lock);
402
403 /* find a suitable table if we don't already have one */
404 while (current_detail == NULL ||
405 current_index >= current_detail->hash_size) {
406 if (current_detail)
407 next = current_detail->others.next;
408 else
409 next = cache_list.next;
410 if (next == &cache_list) {
411 current_detail = NULL;
412 spin_unlock(&cache_list_lock);
413 return -1;
414 }
415 current_detail = list_entry(next, struct cache_detail, others);
NeilBrownc5b29f82010-08-12 16:55:22 +1000416 if (current_detail->nextcheck > seconds_since_boot())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 current_index = current_detail->hash_size;
418 else {
419 current_index = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +1000420 current_detail->nextcheck = seconds_since_boot()+30*60;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 }
422 }
423
424 /* find a non-empty bucket in the table */
425 while (current_detail &&
426 current_index < current_detail->hash_size &&
427 current_detail->hash_table[current_index] == NULL)
428 current_index++;
429
430 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 if (current_detail && current_index < current_detail->hash_size) {
433 struct cache_head *ch, **cp;
434 struct cache_detail *d;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800435
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 write_lock(&current_detail->hash_lock);
437
438 /* Ok, now to clean this strand */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 cp = & current_detail->hash_table[current_index];
NeilBrown3af49742010-02-03 17:31:31 +1100441 for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (current_detail->nextcheck > ch->expiry_time)
443 current_detail->nextcheck = ch->expiry_time+1;
NeilBrown2f50d8b2010-02-03 17:31:31 +1100444 if (!cache_is_expired(current_detail, ch))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 *cp = ch->next;
448 ch->next = NULL;
449 current_detail->entries--;
450 rv = 1;
NeilBrown3af49742010-02-03 17:31:31 +1100451 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 }
NeilBrown3af49742010-02-03 17:31:31 +1100453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 write_unlock(&current_detail->hash_lock);
455 d = current_detail;
456 if (!ch)
457 current_index ++;
458 spin_unlock(&cache_list_lock);
NeilBrown5c4d2632009-08-04 15:22:38 +1000459 if (ch) {
NeilBrown3af49742010-02-03 17:31:31 +1100460 if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
461 cache_dequeue(current_detail, ch);
NeilBrown5c4d2632009-08-04 15:22:38 +1000462 cache_revisit_request(ch);
NeilBrownbaab9352006-03-27 01:15:09 -0800463 cache_put(ch, d);
NeilBrown5c4d2632009-08-04 15:22:38 +1000464 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 } else
466 spin_unlock(&cache_list_lock);
467
468 return rv;
469}
470
471/*
472 * We want to regularly clean the cache, so we need to schedule some work ...
473 */
David Howells65f27f32006-11-22 14:55:48 +0000474static void do_cache_clean(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475{
476 int delay = 5;
477 if (cache_clean() == -1)
Anton Blanchard6aad89c2009-06-10 12:52:21 -0700478 delay = round_jiffies_relative(30*HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
480 if (list_empty(&cache_list))
481 delay = 0;
482
483 if (delay)
484 schedule_delayed_work(&cache_cleaner, delay);
485}
486
487
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800488/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 * Clean all caches promptly. This just calls cache_clean
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800490 * repeatedly until we are sure that every cache has had a chance to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 * be fully cleaned
492 */
493void cache_flush(void)
494{
495 while (cache_clean() != -1)
496 cond_resched();
497 while (cache_clean() != -1)
498 cond_resched();
499}
Trond Myklebust24c37672008-12-23 16:30:12 -0500500EXPORT_SYMBOL_GPL(cache_flush);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
502void cache_purge(struct cache_detail *detail)
503{
504 detail->flush_time = LONG_MAX;
NeilBrownc5b29f82010-08-12 16:55:22 +1000505 detail->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 cache_flush();
507 detail->flush_time = 1;
508}
Trond Myklebust24c37672008-12-23 16:30:12 -0500509EXPORT_SYMBOL_GPL(cache_purge);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
511
512/*
513 * Deferral and Revisiting of Requests.
514 *
515 * If a cache lookup finds a pending entry, we
516 * need to defer the request and revisit it later.
517 * All deferred requests are stored in a hash table,
518 * indexed by "struct cache_head *".
519 * As it may be wasteful to store a whole request
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800520 * structure, we allow the request to provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 * deferred form, which must contain a
522 * 'struct cache_deferred_req'
523 * This cache_deferred_req contains a method to allow
524 * it to be revisited when cache info is available
525 */
526
527#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
528#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
529
530#define DFR_MAX 300 /* ??? */
531
532static DEFINE_SPINLOCK(cache_defer_lock);
533static LIST_HEAD(cache_defer_list);
NeilBrown11174492010-08-12 17:04:08 +1000534static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535static int cache_defer_cnt;
536
J. Bruce Fields6610f722010-08-26 13:19:52 -0400537static void __unhash_deferred_req(struct cache_deferred_req *dreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538{
NeilBrown11174492010-08-12 17:04:08 +1000539 hlist_del_init(&dreq->hash);
NeilBrowne33534d2010-10-07 15:29:46 +1100540 if (!list_empty(&dreq->recent)) {
541 list_del_init(&dreq->recent);
542 cache_defer_cnt--;
543 }
J. Bruce Fields6610f722010-08-26 13:19:52 -0400544}
545
546static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
547{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 int hash = DFR_HASH(item);
549
NeilBrowne33534d2010-10-07 15:29:46 +1100550 INIT_LIST_HEAD(&dreq->recent);
NeilBrown11174492010-08-12 17:04:08 +1000551 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
J. Bruce Fields6610f722010-08-26 13:19:52 -0400552}
553
NeilBrowne33534d2010-10-07 15:29:46 +1100554static void setup_deferral(struct cache_deferred_req *dreq,
555 struct cache_head *item,
556 int count_me)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 dreq->item = item;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560
561 spin_lock(&cache_defer_lock);
562
J. Bruce Fields6610f722010-08-26 13:19:52 -0400563 __hash_deferred_req(dreq, item);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
NeilBrowne33534d2010-10-07 15:29:46 +1100565 if (count_me) {
566 cache_defer_cnt++;
567 list_add(&dreq->recent, &cache_defer_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 }
NeilBrowne33534d2010-10-07 15:29:46 +1100569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 spin_unlock(&cache_defer_lock);
571
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
J. Bruce Fields3211af12010-08-26 16:56:23 -0400574struct thread_deferred_req {
575 struct cache_deferred_req handle;
576 struct completion completion;
577};
578
579static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
580{
581 struct thread_deferred_req *dr =
582 container_of(dreq, struct thread_deferred_req, handle);
583 complete(&dr->completion);
584}
585
NeilBrownd29068c42010-10-07 15:29:46 +1100586static void cache_wait_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400587{
588 struct thread_deferred_req sleeper;
589 struct cache_deferred_req *dreq = &sleeper.handle;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400590
591 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
592 dreq->revisit = cache_restart_thread;
593
NeilBrowne33534d2010-10-07 15:29:46 +1100594 setup_deferral(dreq, item, 0);
J. Bruce Fields3211af12010-08-26 16:56:23 -0400595
NeilBrownd29068c42010-10-07 15:29:46 +1100596 if (!test_bit(CACHE_PENDING, &item->flags) ||
NeilBrown277f68d2010-09-22 12:55:06 +1000597 wait_for_completion_interruptible_timeout(
J. Bruce Fields3211af12010-08-26 16:56:23 -0400598 &sleeper.completion, req->thread_wait) <= 0) {
599 /* The completion wasn't completed, so we need
600 * to clean up
601 */
602 spin_lock(&cache_defer_lock);
NeilBrown11174492010-08-12 17:04:08 +1000603 if (!hlist_unhashed(&sleeper.handle.hash)) {
J. Bruce Fields3211af12010-08-26 16:56:23 -0400604 __unhash_deferred_req(&sleeper.handle);
605 spin_unlock(&cache_defer_lock);
606 } else {
607 /* cache_revisit_request already removed
608 * this from the hash table, but hasn't
609 * called ->revisit yet. It will very soon
610 * and we need to wait for it.
611 */
612 spin_unlock(&cache_defer_lock);
613 wait_for_completion(&sleeper.completion);
614 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 }
J. Bruce Fields3211af12010-08-26 16:56:23 -0400616}
617
NeilBrowne33534d2010-10-07 15:29:46 +1100618static void cache_limit_defers(void)
619{
620 /* Make sure we haven't exceed the limit of allowed deferred
621 * requests.
622 */
623 struct cache_deferred_req *discard = NULL;
624
625 if (cache_defer_cnt <= DFR_MAX)
626 return;
627
628 spin_lock(&cache_defer_lock);
629
630 /* Consider removing either the first or the last */
631 if (cache_defer_cnt > DFR_MAX) {
632 if (net_random() & 1)
633 discard = list_entry(cache_defer_list.next,
634 struct cache_deferred_req, recent);
635 else
636 discard = list_entry(cache_defer_list.prev,
637 struct cache_deferred_req, recent);
638 __unhash_deferred_req(discard);
639 }
640 spin_unlock(&cache_defer_lock);
641 if (discard)
642 discard->revisit(discard, 1);
643}
644
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500645/* Return true if and only if a deferred request is queued. */
646static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400647{
648 struct cache_deferred_req *dreq;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400649
J. Bruce Fields3211af12010-08-26 16:56:23 -0400650 if (req->thread_wait) {
NeilBrownd29068c42010-10-07 15:29:46 +1100651 cache_wait_req(req, item);
652 if (!test_bit(CACHE_PENDING, &item->flags))
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500653 return false;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400654 }
655 dreq = req->defer(req);
656 if (dreq == NULL)
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500657 return false;
NeilBrowne33534d2010-10-07 15:29:46 +1100658 setup_deferral(dreq, item, 1);
NeilBrownd29068c42010-10-07 15:29:46 +1100659 if (!test_bit(CACHE_PENDING, &item->flags))
660 /* Bit could have been cleared before we managed to
661 * set up the deferral, so need to revisit just in case
662 */
663 cache_revisit_request(item);
NeilBrowne33534d2010-10-07 15:29:46 +1100664
665 cache_limit_defers();
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500666 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667}
668
669static void cache_revisit_request(struct cache_head *item)
670{
671 struct cache_deferred_req *dreq;
672 struct list_head pending;
NeilBrown11174492010-08-12 17:04:08 +1000673 struct hlist_node *lp, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 int hash = DFR_HASH(item);
675
676 INIT_LIST_HEAD(&pending);
677 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800678
NeilBrown11174492010-08-12 17:04:08 +1000679 hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash)
680 if (dreq->item == item) {
681 __unhash_deferred_req(dreq);
682 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 }
NeilBrown11174492010-08-12 17:04:08 +1000684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 spin_unlock(&cache_defer_lock);
686
687 while (!list_empty(&pending)) {
688 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
689 list_del_init(&dreq->recent);
690 dreq->revisit(dreq, 0);
691 }
692}
693
694void cache_clean_deferred(void *owner)
695{
696 struct cache_deferred_req *dreq, *tmp;
697 struct list_head pending;
698
699
700 INIT_LIST_HEAD(&pending);
701 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
704 if (dreq->owner == owner) {
J. Bruce Fields6610f722010-08-26 13:19:52 -0400705 __unhash_deferred_req(dreq);
NeilBrowne95dffa2010-09-22 12:55:06 +1000706 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 }
708 }
709 spin_unlock(&cache_defer_lock);
710
711 while (!list_empty(&pending)) {
712 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
713 list_del_init(&dreq->recent);
714 dreq->revisit(dreq, 1);
715 }
716}
717
718/*
719 * communicate with user-space
720 *
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500721 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
722 * On read, you get a full request, or block.
723 * On write, an update request is processed.
724 * Poll works if anything to read, and always allows write.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800726 * Implemented by linked list of requests. Each open file has
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500727 * a ->private that also exists in this list. New requests are added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 * to the end and may wakeup and preceding readers.
729 * New readers are added to the head. If, on read, an item is found with
730 * CACHE_UPCALLING clear, we free it from the list.
731 *
732 */
733
734static DEFINE_SPINLOCK(queue_lock);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800735static DEFINE_MUTEX(queue_io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737struct cache_queue {
738 struct list_head list;
739 int reader; /* if 0, then request */
740};
741struct cache_request {
742 struct cache_queue q;
743 struct cache_head *item;
744 char * buf;
745 int len;
746 int readers;
747};
748struct cache_reader {
749 struct cache_queue q;
750 int offset; /* if non-0, we have a refcnt on next request */
751};
752
Trond Myklebust173912a2009-08-09 15:14:29 -0400753static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
754 loff_t *ppos, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755{
756 struct cache_reader *rp = filp->private_data;
757 struct cache_request *rq;
Trond Myklebustda770052009-08-09 15:14:28 -0400758 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 int err;
760
761 if (count == 0)
762 return 0;
763
Trond Myklebustda770052009-08-09 15:14:28 -0400764 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 * readers on this file */
766 again:
767 spin_lock(&queue_lock);
768 /* need to find next request */
769 while (rp->q.list.next != &cd->queue &&
770 list_entry(rp->q.list.next, struct cache_queue, list)
771 ->reader) {
772 struct list_head *next = rp->q.list.next;
773 list_move(&rp->q.list, next);
774 }
775 if (rp->q.list.next == &cd->queue) {
776 spin_unlock(&queue_lock);
Trond Myklebustda770052009-08-09 15:14:28 -0400777 mutex_unlock(&inode->i_mutex);
Kris Katterjohn09a62662006-01-08 22:24:28 -0800778 BUG_ON(rp->offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 return 0;
780 }
781 rq = container_of(rp->q.list.next, struct cache_request, q.list);
Kris Katterjohn09a62662006-01-08 22:24:28 -0800782 BUG_ON(rq->q.reader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 if (rp->offset == 0)
784 rq->readers++;
785 spin_unlock(&queue_lock);
786
787 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
788 err = -EAGAIN;
789 spin_lock(&queue_lock);
790 list_move(&rp->q.list, &rq->q.list);
791 spin_unlock(&queue_lock);
792 } else {
793 if (rp->offset + count > rq->len)
794 count = rq->len - rp->offset;
795 err = -EFAULT;
796 if (copy_to_user(buf, rq->buf + rp->offset, count))
797 goto out;
798 rp->offset += count;
799 if (rp->offset >= rq->len) {
800 rp->offset = 0;
801 spin_lock(&queue_lock);
802 list_move(&rp->q.list, &rq->q.list);
803 spin_unlock(&queue_lock);
804 }
805 err = 0;
806 }
807 out:
808 if (rp->offset == 0) {
809 /* need to release rq */
810 spin_lock(&queue_lock);
811 rq->readers--;
812 if (rq->readers == 0 &&
813 !test_bit(CACHE_PENDING, &rq->item->flags)) {
814 list_del(&rq->q.list);
815 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800816 cache_put(rq->item, cd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 kfree(rq->buf);
818 kfree(rq);
819 } else
820 spin_unlock(&queue_lock);
821 }
822 if (err == -EAGAIN)
823 goto again;
Trond Myklebustda770052009-08-09 15:14:28 -0400824 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 return err ? err : count;
826}
827
Trond Myklebustda770052009-08-09 15:14:28 -0400828static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
829 size_t count, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830{
Trond Myklebustda770052009-08-09 15:14:28 -0400831 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832
Dan Carpenter6d8d1742012-01-18 12:56:02 +0300833 if (count == 0)
834 return -EINVAL;
Trond Myklebustda770052009-08-09 15:14:28 -0400835 if (copy_from_user(kaddr, buf, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 return -EFAULT;
Trond Myklebustda770052009-08-09 15:14:28 -0400837 kaddr[count] = '\0';
838 ret = cd->cache_parse(cd, kaddr, count);
839 if (!ret)
840 ret = count;
841 return ret;
842}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843
Trond Myklebustda770052009-08-09 15:14:28 -0400844static ssize_t cache_slow_downcall(const char __user *buf,
845 size_t count, struct cache_detail *cd)
846{
847 static char write_buf[8192]; /* protected by queue_io_mutex */
848 ssize_t ret = -EINVAL;
849
850 if (count >= sizeof(write_buf))
851 goto out;
852 mutex_lock(&queue_io_mutex);
853 ret = cache_do_downcall(write_buf, buf, count, cd);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800854 mutex_unlock(&queue_io_mutex);
Trond Myklebustda770052009-08-09 15:14:28 -0400855out:
856 return ret;
857}
858
859static ssize_t cache_downcall(struct address_space *mapping,
860 const char __user *buf,
861 size_t count, struct cache_detail *cd)
862{
863 struct page *page;
864 char *kaddr;
865 ssize_t ret = -ENOMEM;
866
867 if (count >= PAGE_CACHE_SIZE)
868 goto out_slow;
869
870 page = find_or_create_page(mapping, 0, GFP_KERNEL);
871 if (!page)
872 goto out_slow;
873
874 kaddr = kmap(page);
875 ret = cache_do_downcall(kaddr, buf, count, cd);
876 kunmap(page);
877 unlock_page(page);
878 page_cache_release(page);
879 return ret;
880out_slow:
881 return cache_slow_downcall(buf, count, cd);
882}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Trond Myklebust173912a2009-08-09 15:14:29 -0400884static ssize_t cache_write(struct file *filp, const char __user *buf,
885 size_t count, loff_t *ppos,
886 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887{
Trond Myklebustda770052009-08-09 15:14:28 -0400888 struct address_space *mapping = filp->f_mapping;
889 struct inode *inode = filp->f_path.dentry->d_inode;
Trond Myklebustda770052009-08-09 15:14:28 -0400890 ssize_t ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
Trond Myklebustda770052009-08-09 15:14:28 -0400892 if (!cd->cache_parse)
893 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
Trond Myklebustda770052009-08-09 15:14:28 -0400895 mutex_lock(&inode->i_mutex);
896 ret = cache_downcall(mapping, buf, count, cd);
897 mutex_unlock(&inode->i_mutex);
898out:
899 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900}
901
902static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
903
Trond Myklebust173912a2009-08-09 15:14:29 -0400904static unsigned int cache_poll(struct file *filp, poll_table *wait,
905 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906{
907 unsigned int mask;
908 struct cache_reader *rp = filp->private_data;
909 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
911 poll_wait(filp, &queue_wait, wait);
912
913 /* alway allow write */
914 mask = POLL_OUT | POLLWRNORM;
915
916 if (!rp)
917 return mask;
918
919 spin_lock(&queue_lock);
920
921 for (cq= &rp->q; &cq->list != &cd->queue;
922 cq = list_entry(cq->list.next, struct cache_queue, list))
923 if (!cq->reader) {
924 mask |= POLLIN | POLLRDNORM;
925 break;
926 }
927 spin_unlock(&queue_lock);
928 return mask;
929}
930
Trond Myklebust173912a2009-08-09 15:14:29 -0400931static int cache_ioctl(struct inode *ino, struct file *filp,
932 unsigned int cmd, unsigned long arg,
933 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934{
935 int len = 0;
936 struct cache_reader *rp = filp->private_data;
937 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938
939 if (cmd != FIONREAD || !rp)
940 return -EINVAL;
941
942 spin_lock(&queue_lock);
943
944 /* only find the length remaining in current request,
945 * or the length of the next request
946 */
947 for (cq= &rp->q; &cq->list != &cd->queue;
948 cq = list_entry(cq->list.next, struct cache_queue, list))
949 if (!cq->reader) {
950 struct cache_request *cr =
951 container_of(cq, struct cache_request, q);
952 len = cr->len - rp->offset;
953 break;
954 }
955 spin_unlock(&queue_lock);
956
957 return put_user(len, (int __user *)arg);
958}
959
Trond Myklebust173912a2009-08-09 15:14:29 -0400960static int cache_open(struct inode *inode, struct file *filp,
961 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962{
963 struct cache_reader *rp = NULL;
964
Trond Myklebustf7e86ab2009-08-19 18:13:00 -0400965 if (!cd || !try_module_get(cd->owner))
966 return -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 nonseekable_open(inode, filp);
968 if (filp->f_mode & FMODE_READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
970 if (!rp)
971 return -ENOMEM;
972 rp->offset = 0;
973 rp->q.reader = 1;
974 atomic_inc(&cd->readers);
975 spin_lock(&queue_lock);
976 list_add(&rp->q.list, &cd->queue);
977 spin_unlock(&queue_lock);
978 }
979 filp->private_data = rp;
980 return 0;
981}
982
Trond Myklebust173912a2009-08-09 15:14:29 -0400983static int cache_release(struct inode *inode, struct file *filp,
984 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985{
986 struct cache_reader *rp = filp->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987
988 if (rp) {
989 spin_lock(&queue_lock);
990 if (rp->offset) {
991 struct cache_queue *cq;
992 for (cq= &rp->q; &cq->list != &cd->queue;
993 cq = list_entry(cq->list.next, struct cache_queue, list))
994 if (!cq->reader) {
995 container_of(cq, struct cache_request, q)
996 ->readers--;
997 break;
998 }
999 rp->offset = 0;
1000 }
1001 list_del(&rp->q.list);
1002 spin_unlock(&queue_lock);
1003
1004 filp->private_data = NULL;
1005 kfree(rp);
1006
NeilBrownc5b29f82010-08-12 16:55:22 +10001007 cd->last_close = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 atomic_dec(&cd->readers);
1009 }
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001010 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 return 0;
1012}
1013
1014
1015
NeilBrownf866a812009-08-04 15:22:38 +10001016static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017{
1018 struct cache_queue *cq;
1019 spin_lock(&queue_lock);
1020 list_for_each_entry(cq, &detail->queue, list)
1021 if (!cq->reader) {
1022 struct cache_request *cr = container_of(cq, struct cache_request, q);
1023 if (cr->item != ch)
1024 continue;
1025 if (cr->readers != 0)
NeilBrown4013ede2006-03-27 01:15:07 -08001026 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 list_del(&cr->q.list);
1028 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -08001029 cache_put(cr->item, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 kfree(cr->buf);
1031 kfree(cr);
1032 return;
1033 }
1034 spin_unlock(&queue_lock);
1035}
1036
1037/*
1038 * Support routines for text-based upcalls.
1039 * Fields are separated by spaces.
1040 * Fields are either mangled to quote space tab newline slosh with slosh
1041 * or a hexified with a leading \x
1042 * Record is terminated with newline.
1043 *
1044 */
1045
1046void qword_add(char **bpp, int *lp, char *str)
1047{
1048 char *bp = *bpp;
1049 int len = *lp;
1050 char c;
1051
1052 if (len < 0) return;
1053
1054 while ((c=*str++) && len)
1055 switch(c) {
1056 case ' ':
1057 case '\t':
1058 case '\n':
1059 case '\\':
1060 if (len >= 4) {
1061 *bp++ = '\\';
1062 *bp++ = '0' + ((c & 0300)>>6);
1063 *bp++ = '0' + ((c & 0070)>>3);
1064 *bp++ = '0' + ((c & 0007)>>0);
1065 }
1066 len -= 4;
1067 break;
1068 default:
1069 *bp++ = c;
1070 len--;
1071 }
1072 if (c || len <1) len = -1;
1073 else {
1074 *bp++ = ' ';
1075 len--;
1076 }
1077 *bpp = bp;
1078 *lp = len;
1079}
Trond Myklebust24c37672008-12-23 16:30:12 -05001080EXPORT_SYMBOL_GPL(qword_add);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081
1082void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1083{
1084 char *bp = *bpp;
1085 int len = *lp;
1086
1087 if (len < 0) return;
1088
1089 if (len > 2) {
1090 *bp++ = '\\';
1091 *bp++ = 'x';
1092 len -= 2;
1093 while (blen && len >= 2) {
1094 unsigned char c = *buf++;
1095 *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
1096 *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
1097 len -= 2;
1098 blen--;
1099 }
1100 }
1101 if (blen || len<1) len = -1;
1102 else {
1103 *bp++ = ' ';
1104 len--;
1105 }
1106 *bpp = bp;
1107 *lp = len;
1108}
Trond Myklebust24c37672008-12-23 16:30:12 -05001109EXPORT_SYMBOL_GPL(qword_addhex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110
1111static void warn_no_listener(struct cache_detail *detail)
1112{
1113 if (detail->last_warn != detail->last_close) {
1114 detail->last_warn = detail->last_close;
1115 if (detail->warn_no_listener)
Trond Myklebust2da8ca22009-08-09 15:14:26 -04001116 detail->warn_no_listener(detail, detail->last_close != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 }
1118}
1119
J. Bruce Fields06497522010-09-19 22:55:06 -04001120static bool cache_listeners_exist(struct cache_detail *detail)
1121{
1122 if (atomic_read(&detail->readers))
1123 return true;
1124 if (detail->last_close == 0)
1125 /* This cache was never opened */
1126 return false;
1127 if (detail->last_close < seconds_since_boot() - 30)
1128 /*
1129 * We allow for the possibility that someone might
1130 * restart a userspace daemon without restarting the
1131 * server; but after 30 seconds, we give up.
1132 */
1133 return false;
1134 return true;
1135}
1136
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137/*
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001138 * register an upcall request to user-space and queue it up for read() by the
1139 * upcall daemon.
1140 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 * Each request is at most one page long.
1142 */
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001143int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h,
1144 void (*cache_request)(struct cache_detail *,
1145 struct cache_head *,
1146 char **,
1147 int *))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148{
1149
1150 char *buf;
1151 struct cache_request *crq;
1152 char *bp;
1153 int len;
1154
J. Bruce Fields06497522010-09-19 22:55:06 -04001155 if (!cache_listeners_exist(detail)) {
1156 warn_no_listener(detail);
1157 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 }
1159
1160 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1161 if (!buf)
1162 return -EAGAIN;
1163
1164 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1165 if (!crq) {
1166 kfree(buf);
1167 return -EAGAIN;
1168 }
1169
1170 bp = buf; len = PAGE_SIZE;
1171
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001172 cache_request(detail, h, &bp, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173
1174 if (len < 0) {
1175 kfree(buf);
1176 kfree(crq);
1177 return -EAGAIN;
1178 }
1179 crq->q.reader = 0;
1180 crq->item = cache_get(h);
1181 crq->buf = buf;
1182 crq->len = PAGE_SIZE - len;
1183 crq->readers = 0;
1184 spin_lock(&queue_lock);
1185 list_add_tail(&crq->q.list, &detail->queue);
1186 spin_unlock(&queue_lock);
1187 wake_up(&queue_wait);
1188 return 0;
1189}
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001190EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191
1192/*
1193 * parse a message from user-space and pass it
1194 * to an appropriate cache
1195 * Messages are, like requests, separated into fields by
1196 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1197 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001198 * Message is
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 * reply cachename expiry key ... content....
1200 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001201 * key and content are both parsed by cache
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 */
1203
1204#define isodigit(c) (isdigit(c) && c <= '7')
1205int qword_get(char **bpp, char *dest, int bufsize)
1206{
1207 /* return bytes copied, or -1 on error */
1208 char *bp = *bpp;
1209 int len = 0;
1210
1211 while (*bp == ' ') bp++;
1212
1213 if (bp[0] == '\\' && bp[1] == 'x') {
1214 /* HEX STRING */
1215 bp += 2;
Andy Shevchenkoe7f483e2010-09-21 09:40:25 +03001216 while (len < bufsize) {
1217 int h, l;
1218
1219 h = hex_to_bin(bp[0]);
1220 if (h < 0)
1221 break;
1222
1223 l = hex_to_bin(bp[1]);
1224 if (l < 0)
1225 break;
1226
1227 *dest++ = (h << 4) | l;
1228 bp += 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 len++;
1230 }
1231 } else {
1232 /* text with \nnn octal quoting */
1233 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1234 if (*bp == '\\' &&
1235 isodigit(bp[1]) && (bp[1] <= '3') &&
1236 isodigit(bp[2]) &&
1237 isodigit(bp[3])) {
1238 int byte = (*++bp -'0');
1239 bp++;
1240 byte = (byte << 3) | (*bp++ - '0');
1241 byte = (byte << 3) | (*bp++ - '0');
1242 *dest++ = byte;
1243 len++;
1244 } else {
1245 *dest++ = *bp++;
1246 len++;
1247 }
1248 }
1249 }
1250
1251 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1252 return -1;
1253 while (*bp == ' ') bp++;
1254 *bpp = bp;
1255 *dest = '\0';
1256 return len;
1257}
Trond Myklebust24c37672008-12-23 16:30:12 -05001258EXPORT_SYMBOL_GPL(qword_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259
1260
1261/*
1262 * support /proc/sunrpc/cache/$CACHENAME/content
1263 * as a seqfile.
1264 * We call ->cache_show passing NULL for the item to
1265 * get a header, then pass each real item in the cache
1266 */
1267
1268struct handle {
1269 struct cache_detail *cd;
1270};
1271
1272static void *c_start(struct seq_file *m, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001273 __acquires(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274{
1275 loff_t n = *pos;
Eric Dumazet95c96172012-04-15 05:58:06 +00001276 unsigned int hash, entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 struct cache_head *ch;
1278 struct cache_detail *cd = ((struct handle*)m->private)->cd;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001279
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280
1281 read_lock(&cd->hash_lock);
1282 if (!n--)
1283 return SEQ_START_TOKEN;
1284 hash = n >> 32;
1285 entry = n & ((1LL<<32) - 1);
1286
1287 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1288 if (!entry--)
1289 return ch;
1290 n &= ~((1LL<<32) - 1);
1291 do {
1292 hash++;
1293 n += 1LL<<32;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001294 } while(hash < cd->hash_size &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 cd->hash_table[hash]==NULL);
1296 if (hash >= cd->hash_size)
1297 return NULL;
1298 *pos = n+1;
1299 return cd->hash_table[hash];
1300}
1301
1302static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1303{
1304 struct cache_head *ch = p;
1305 int hash = (*pos >> 32);
1306 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1307
1308 if (p == SEQ_START_TOKEN)
1309 hash = 0;
1310 else if (ch->next == NULL) {
1311 hash++;
1312 *pos += 1LL<<32;
1313 } else {
1314 ++*pos;
1315 return ch->next;
1316 }
1317 *pos &= ~((1LL<<32) - 1);
1318 while (hash < cd->hash_size &&
1319 cd->hash_table[hash] == NULL) {
1320 hash++;
1321 *pos += 1LL<<32;
1322 }
1323 if (hash >= cd->hash_size)
1324 return NULL;
1325 ++*pos;
1326 return cd->hash_table[hash];
1327}
1328
1329static void c_stop(struct seq_file *m, void *p)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001330 __releases(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331{
1332 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1333 read_unlock(&cd->hash_lock);
1334}
1335
1336static int c_show(struct seq_file *m, void *p)
1337{
1338 struct cache_head *cp = p;
1339 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1340
1341 if (p == SEQ_START_TOKEN)
1342 return cd->cache_show(m, cd, NULL);
1343
1344 ifdebug(CACHE)
NeilBrown4013ede2006-03-27 01:15:07 -08001345 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
NeilBrownc5b29f82010-08-12 16:55:22 +10001346 convert_to_wallclock(cp->expiry_time),
1347 atomic_read(&cp->ref.refcount), cp->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 cache_get(cp);
1349 if (cache_check(cd, cp, NULL))
1350 /* cache_check does a cache_put on failure */
1351 seq_printf(m, "# ");
NeilBrown200724a2012-07-12 10:37:34 +10001352 else {
1353 if (cache_is_expired(cd, cp))
1354 seq_printf(m, "# ");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 cache_put(cp, cd);
NeilBrown200724a2012-07-12 10:37:34 +10001356 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357
1358 return cd->cache_show(m, cd, cp);
1359}
1360
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001361static const struct seq_operations cache_content_op = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 .start = c_start,
1363 .next = c_next,
1364 .stop = c_stop,
1365 .show = c_show,
1366};
1367
Trond Myklebust173912a2009-08-09 15:14:29 -04001368static int content_open(struct inode *inode, struct file *file,
1369 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 struct handle *han;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001373 if (!cd || !try_module_get(cd->owner))
1374 return -EACCES;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001375 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
Li Zefana5990ea2010-03-11 14:08:10 -08001376 if (han == NULL) {
1377 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378 return -ENOMEM;
Li Zefana5990ea2010-03-11 14:08:10 -08001379 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380
1381 han->cd = cd;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001382 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001385static int content_release(struct inode *inode, struct file *file,
1386 struct cache_detail *cd)
1387{
1388 int ret = seq_release_private(inode, file);
1389 module_put(cd->owner);
1390 return ret;
1391}
1392
1393static int open_flush(struct inode *inode, struct file *file,
1394 struct cache_detail *cd)
1395{
1396 if (!cd || !try_module_get(cd->owner))
1397 return -EACCES;
1398 return nonseekable_open(inode, file);
1399}
1400
1401static int release_flush(struct inode *inode, struct file *file,
1402 struct cache_detail *cd)
1403{
1404 module_put(cd->owner);
1405 return 0;
1406}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407
1408static ssize_t read_flush(struct file *file, char __user *buf,
Trond Myklebust173912a2009-08-09 15:14:29 -04001409 size_t count, loff_t *ppos,
1410 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 char tbuf[20];
1413 unsigned long p = *ppos;
Chuck Lever01b29692007-10-26 13:31:20 -04001414 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415
NeilBrownc5b29f82010-08-12 16:55:22 +10001416 sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417 len = strlen(tbuf);
1418 if (p >= len)
1419 return 0;
1420 len -= p;
Chuck Lever01b29692007-10-26 13:31:20 -04001421 if (len > count)
1422 len = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 if (copy_to_user(buf, (void*)(tbuf+p), len))
Chuck Lever01b29692007-10-26 13:31:20 -04001424 return -EFAULT;
1425 *ppos += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001426 return len;
1427}
1428
Trond Myklebust173912a2009-08-09 15:14:29 -04001429static ssize_t write_flush(struct file *file, const char __user *buf,
1430 size_t count, loff_t *ppos,
1431 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433 char tbuf[20];
NeilBrownc5b29f82010-08-12 16:55:22 +10001434 char *bp, *ep;
1435
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 if (*ppos || count > sizeof(tbuf)-1)
1437 return -EINVAL;
1438 if (copy_from_user(tbuf, buf, count))
1439 return -EFAULT;
1440 tbuf[count] = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +10001441 simple_strtoul(tbuf, &ep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 if (*ep && *ep != '\n')
1443 return -EINVAL;
1444
NeilBrownc5b29f82010-08-12 16:55:22 +10001445 bp = tbuf;
1446 cd->flush_time = get_expiry(&bp);
1447 cd->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 cache_flush();
1449
1450 *ppos += count;
1451 return count;
1452}
1453
Trond Myklebust173912a2009-08-09 15:14:29 -04001454static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1455 size_t count, loff_t *ppos)
1456{
1457 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1458
1459 return cache_read(filp, buf, count, ppos, cd);
1460}
1461
1462static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1463 size_t count, loff_t *ppos)
1464{
1465 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1466
1467 return cache_write(filp, buf, count, ppos, cd);
1468}
1469
1470static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1471{
1472 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1473
1474 return cache_poll(filp, wait, cd);
1475}
1476
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001477static long cache_ioctl_procfs(struct file *filp,
1478 unsigned int cmd, unsigned long arg)
Trond Myklebust173912a2009-08-09 15:14:29 -04001479{
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001480 struct inode *inode = filp->f_path.dentry->d_inode;
Trond Myklebust173912a2009-08-09 15:14:29 -04001481 struct cache_detail *cd = PDE(inode)->data;
1482
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001483 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001484}
1485
1486static int cache_open_procfs(struct inode *inode, struct file *filp)
1487{
1488 struct cache_detail *cd = PDE(inode)->data;
1489
1490 return cache_open(inode, filp, cd);
1491}
1492
1493static int cache_release_procfs(struct inode *inode, struct file *filp)
1494{
1495 struct cache_detail *cd = PDE(inode)->data;
1496
1497 return cache_release(inode, filp, cd);
1498}
1499
1500static const struct file_operations cache_file_operations_procfs = {
1501 .owner = THIS_MODULE,
1502 .llseek = no_llseek,
1503 .read = cache_read_procfs,
1504 .write = cache_write_procfs,
1505 .poll = cache_poll_procfs,
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001506 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
Trond Myklebust173912a2009-08-09 15:14:29 -04001507 .open = cache_open_procfs,
1508 .release = cache_release_procfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001509};
Trond Myklebust173912a2009-08-09 15:14:29 -04001510
1511static int content_open_procfs(struct inode *inode, struct file *filp)
1512{
1513 struct cache_detail *cd = PDE(inode)->data;
1514
1515 return content_open(inode, filp, cd);
1516}
1517
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001518static int content_release_procfs(struct inode *inode, struct file *filp)
1519{
1520 struct cache_detail *cd = PDE(inode)->data;
1521
1522 return content_release(inode, filp, cd);
1523}
1524
Trond Myklebust173912a2009-08-09 15:14:29 -04001525static const struct file_operations content_file_operations_procfs = {
1526 .open = content_open_procfs,
1527 .read = seq_read,
1528 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001529 .release = content_release_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001530};
1531
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001532static int open_flush_procfs(struct inode *inode, struct file *filp)
1533{
1534 struct cache_detail *cd = PDE(inode)->data;
1535
1536 return open_flush(inode, filp, cd);
1537}
1538
1539static int release_flush_procfs(struct inode *inode, struct file *filp)
1540{
1541 struct cache_detail *cd = PDE(inode)->data;
1542
1543 return release_flush(inode, filp, cd);
1544}
1545
Trond Myklebust173912a2009-08-09 15:14:29 -04001546static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1547 size_t count, loff_t *ppos)
1548{
1549 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1550
1551 return read_flush(filp, buf, count, ppos, cd);
1552}
1553
1554static ssize_t write_flush_procfs(struct file *filp,
1555 const char __user *buf,
1556 size_t count, loff_t *ppos)
1557{
1558 struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
1559
1560 return write_flush(filp, buf, count, ppos, cd);
1561}
1562
1563static const struct file_operations cache_flush_operations_procfs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001564 .open = open_flush_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001565 .read = read_flush_procfs,
1566 .write = write_flush_procfs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001567 .release = release_flush_procfs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001568 .llseek = no_llseek,
Trond Myklebust173912a2009-08-09 15:14:29 -04001569};
1570
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001571static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001572{
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001573 struct sunrpc_net *sn;
1574
Trond Myklebust173912a2009-08-09 15:14:29 -04001575 if (cd->u.procfs.proc_ent == NULL)
1576 return;
1577 if (cd->u.procfs.flush_ent)
1578 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1579 if (cd->u.procfs.channel_ent)
1580 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1581 if (cd->u.procfs.content_ent)
1582 remove_proc_entry("content", cd->u.procfs.proc_ent);
1583 cd->u.procfs.proc_ent = NULL;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001584 sn = net_generic(net, sunrpc_net_id);
1585 remove_proc_entry(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001586}
1587
1588#ifdef CONFIG_PROC_FS
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001589static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001590{
1591 struct proc_dir_entry *p;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001592 struct sunrpc_net *sn;
Trond Myklebust173912a2009-08-09 15:14:29 -04001593
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001594 sn = net_generic(net, sunrpc_net_id);
1595 cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001596 if (cd->u.procfs.proc_ent == NULL)
1597 goto out_nomem;
1598 cd->u.procfs.channel_ent = NULL;
1599 cd->u.procfs.content_ent = NULL;
1600
1601 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1602 cd->u.procfs.proc_ent,
1603 &cache_flush_operations_procfs, cd);
1604 cd->u.procfs.flush_ent = p;
1605 if (p == NULL)
1606 goto out_nomem;
1607
1608 if (cd->cache_upcall || cd->cache_parse) {
1609 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1610 cd->u.procfs.proc_ent,
1611 &cache_file_operations_procfs, cd);
1612 cd->u.procfs.channel_ent = p;
1613 if (p == NULL)
1614 goto out_nomem;
1615 }
1616 if (cd->cache_show) {
1617 p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
1618 cd->u.procfs.proc_ent,
1619 &content_file_operations_procfs, cd);
1620 cd->u.procfs.content_ent = p;
1621 if (p == NULL)
1622 goto out_nomem;
1623 }
1624 return 0;
1625out_nomem:
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001626 remove_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001627 return -ENOMEM;
1628}
1629#else /* CONFIG_PROC_FS */
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001630static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001631{
1632 return 0;
1633}
1634#endif
1635
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001636void __init cache_initialize(void)
1637{
Tejun Heo203b42f2012-08-21 13:18:23 -07001638 INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001639}
1640
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001641int cache_register_net(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001642{
1643 int ret;
1644
1645 sunrpc_init_cache_detail(cd);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001646 ret = create_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001647 if (ret)
1648 sunrpc_destroy_cache_detail(cd);
1649 return ret;
1650}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001651EXPORT_SYMBOL_GPL(cache_register_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001652
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001653void cache_unregister_net(struct cache_detail *cd, struct net *net)
1654{
1655 remove_cache_proc_entries(cd, net);
1656 sunrpc_destroy_cache_detail(cd);
1657}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001658EXPORT_SYMBOL_GPL(cache_unregister_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001659
Stanislav Kinsbursky0a402d52012-01-19 21:42:21 +04001660struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001661{
Stanislav Kinsbursky0a402d52012-01-19 21:42:21 +04001662 struct cache_detail *cd;
1663
1664 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
1665 if (cd == NULL)
1666 return ERR_PTR(-ENOMEM);
1667
1668 cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *),
1669 GFP_KERNEL);
1670 if (cd->hash_table == NULL) {
1671 kfree(cd);
1672 return ERR_PTR(-ENOMEM);
1673 }
1674 cd->net = net;
1675 return cd;
Trond Myklebust173912a2009-08-09 15:14:29 -04001676}
Stanislav Kinsbursky0a402d52012-01-19 21:42:21 +04001677EXPORT_SYMBOL_GPL(cache_create_net);
1678
1679void cache_destroy_net(struct cache_detail *cd, struct net *net)
1680{
1681 kfree(cd->hash_table);
1682 kfree(cd);
1683}
1684EXPORT_SYMBOL_GPL(cache_destroy_net);
Trond Myklebust8854e822009-08-09 15:14:30 -04001685
1686static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1687 size_t count, loff_t *ppos)
1688{
1689 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1690
1691 return cache_read(filp, buf, count, ppos, cd);
1692}
1693
1694static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1695 size_t count, loff_t *ppos)
1696{
1697 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1698
1699 return cache_write(filp, buf, count, ppos, cd);
1700}
1701
1702static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1703{
1704 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1705
1706 return cache_poll(filp, wait, cd);
1707}
1708
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001709static long cache_ioctl_pipefs(struct file *filp,
Trond Myklebust8854e822009-08-09 15:14:30 -04001710 unsigned int cmd, unsigned long arg)
1711{
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001712 struct inode *inode = filp->f_dentry->d_inode;
Trond Myklebust8854e822009-08-09 15:14:30 -04001713 struct cache_detail *cd = RPC_I(inode)->private;
1714
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001715 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust8854e822009-08-09 15:14:30 -04001716}
1717
1718static int cache_open_pipefs(struct inode *inode, struct file *filp)
1719{
1720 struct cache_detail *cd = RPC_I(inode)->private;
1721
1722 return cache_open(inode, filp, cd);
1723}
1724
1725static int cache_release_pipefs(struct inode *inode, struct file *filp)
1726{
1727 struct cache_detail *cd = RPC_I(inode)->private;
1728
1729 return cache_release(inode, filp, cd);
1730}
1731
1732const struct file_operations cache_file_operations_pipefs = {
1733 .owner = THIS_MODULE,
1734 .llseek = no_llseek,
1735 .read = cache_read_pipefs,
1736 .write = cache_write_pipefs,
1737 .poll = cache_poll_pipefs,
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001738 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
Trond Myklebust8854e822009-08-09 15:14:30 -04001739 .open = cache_open_pipefs,
1740 .release = cache_release_pipefs,
1741};
1742
1743static int content_open_pipefs(struct inode *inode, struct file *filp)
1744{
1745 struct cache_detail *cd = RPC_I(inode)->private;
1746
1747 return content_open(inode, filp, cd);
1748}
1749
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001750static int content_release_pipefs(struct inode *inode, struct file *filp)
1751{
1752 struct cache_detail *cd = RPC_I(inode)->private;
1753
1754 return content_release(inode, filp, cd);
1755}
1756
Trond Myklebust8854e822009-08-09 15:14:30 -04001757const struct file_operations content_file_operations_pipefs = {
1758 .open = content_open_pipefs,
1759 .read = seq_read,
1760 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001761 .release = content_release_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001762};
1763
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001764static int open_flush_pipefs(struct inode *inode, struct file *filp)
1765{
1766 struct cache_detail *cd = RPC_I(inode)->private;
1767
1768 return open_flush(inode, filp, cd);
1769}
1770
1771static int release_flush_pipefs(struct inode *inode, struct file *filp)
1772{
1773 struct cache_detail *cd = RPC_I(inode)->private;
1774
1775 return release_flush(inode, filp, cd);
1776}
1777
Trond Myklebust8854e822009-08-09 15:14:30 -04001778static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1779 size_t count, loff_t *ppos)
1780{
1781 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1782
1783 return read_flush(filp, buf, count, ppos, cd);
1784}
1785
1786static ssize_t write_flush_pipefs(struct file *filp,
1787 const char __user *buf,
1788 size_t count, loff_t *ppos)
1789{
1790 struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private;
1791
1792 return write_flush(filp, buf, count, ppos, cd);
1793}
1794
1795const struct file_operations cache_flush_operations_pipefs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001796 .open = open_flush_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001797 .read = read_flush_pipefs,
1798 .write = write_flush_pipefs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001799 .release = release_flush_pipefs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001800 .llseek = no_llseek,
Trond Myklebust8854e822009-08-09 15:14:30 -04001801};
1802
1803int sunrpc_cache_register_pipefs(struct dentry *parent,
Al Viro64f14262011-07-25 00:35:13 -04001804 const char *name, umode_t umode,
Trond Myklebust8854e822009-08-09 15:14:30 -04001805 struct cache_detail *cd)
1806{
1807 struct qstr q;
1808 struct dentry *dir;
1809 int ret = 0;
1810
Trond Myklebust8854e822009-08-09 15:14:30 -04001811 q.name = name;
1812 q.len = strlen(name);
1813 q.hash = full_name_hash(q.name, q.len);
1814 dir = rpc_create_cache_dir(parent, &q, umode, cd);
1815 if (!IS_ERR(dir))
1816 cd->u.pipefs.dir = dir;
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +03001817 else
Trond Myklebust8854e822009-08-09 15:14:30 -04001818 ret = PTR_ERR(dir);
Trond Myklebust8854e822009-08-09 15:14:30 -04001819 return ret;
1820}
1821EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1822
1823void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1824{
1825 rpc_remove_cache_dir(cd->u.pipefs.dir);
1826 cd->u.pipefs.dir = NULL;
Trond Myklebust8854e822009-08-09 15:14:30 -04001827}
1828EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
1829