blob: ae333c1845bb42f28198cdfb957cd03e7412c14c [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
NeilBrown15a5f6b2006-03-27 01:15:02 -080053struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
54 struct cache_head *key, int hash)
55{
56 struct cache_head **head, **hp;
NeilBrownd202cce2010-02-03 17:31:31 +110057 struct cache_head *new = NULL, *freeme = NULL;
NeilBrown15a5f6b2006-03-27 01:15:02 -080058
59 head = &detail->hash_table[hash];
60
61 read_lock(&detail->hash_lock);
62
63 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
64 struct cache_head *tmp = *hp;
65 if (detail->match(tmp, key)) {
NeilBrownd202cce2010-02-03 17:31:31 +110066 if (cache_is_expired(detail, tmp))
67 /* This entry is expired, we will discard it. */
68 break;
NeilBrown15a5f6b2006-03-27 01:15:02 -080069 cache_get(tmp);
70 read_unlock(&detail->hash_lock);
71 return tmp;
72 }
73 }
74 read_unlock(&detail->hash_lock);
75 /* Didn't find anything, insert an empty entry */
76
77 new = detail->alloc();
78 if (!new)
79 return NULL;
Neil Brown2f349312006-08-05 12:14:29 -070080 /* must fully initialise 'new', else
81 * we might get lose if we need to
82 * cache_put it soon.
83 */
NeilBrown15a5f6b2006-03-27 01:15:02 -080084 cache_init(new);
Neil Brown2f349312006-08-05 12:14:29 -070085 detail->init(new, key);
NeilBrown15a5f6b2006-03-27 01:15:02 -080086
87 write_lock(&detail->hash_lock);
88
89 /* check if entry appeared while we slept */
90 for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
91 struct cache_head *tmp = *hp;
92 if (detail->match(tmp, key)) {
NeilBrownd202cce2010-02-03 17:31:31 +110093 if (cache_is_expired(detail, tmp)) {
94 *hp = tmp->next;
95 tmp->next = NULL;
96 detail->entries --;
97 freeme = tmp;
98 break;
99 }
NeilBrown15a5f6b2006-03-27 01:15:02 -0800100 cache_get(tmp);
101 write_unlock(&detail->hash_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800102 cache_put(new, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800103 return tmp;
104 }
105 }
NeilBrown15a5f6b2006-03-27 01:15:02 -0800106 new->next = *head;
107 *head = new;
108 detail->entries++;
109 cache_get(new);
110 write_unlock(&detail->hash_lock);
111
NeilBrownd202cce2010-02-03 17:31:31 +1100112 if (freeme)
113 cache_put(freeme, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800114 return new;
115}
Trond Myklebust24c37672008-12-23 16:30:12 -0500116EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800117
NeilBrownebd0cb12006-03-27 01:15:08 -0800118
NeilBrownf866a812009-08-04 15:22:38 +1000119static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
NeilBrownebd0cb12006-03-27 01:15:08 -0800120
NeilBrown908329f2009-09-09 16:32:54 +1000121static void cache_fresh_locked(struct cache_head *head, time_t expiry)
NeilBrownebd0cb12006-03-27 01:15:08 -0800122{
123 head->expiry_time = expiry;
NeilBrownc5b29f82010-08-12 16:55:22 +1000124 head->last_refresh = seconds_since_boot();
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500125 smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
NeilBrown908329f2009-09-09 16:32:54 +1000126 set_bit(CACHE_VALID, &head->flags);
NeilBrownebd0cb12006-03-27 01:15:08 -0800127}
128
129static void cache_fresh_unlocked(struct cache_head *head,
NeilBrown908329f2009-09-09 16:32:54 +1000130 struct cache_detail *detail)
NeilBrownebd0cb12006-03-27 01:15:08 -0800131{
NeilBrownebd0cb12006-03-27 01:15:08 -0800132 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
133 cache_revisit_request(head);
NeilBrownf866a812009-08-04 15:22:38 +1000134 cache_dequeue(detail, head);
NeilBrownebd0cb12006-03-27 01:15:08 -0800135 }
136}
137
NeilBrown15a5f6b2006-03-27 01:15:02 -0800138struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
139 struct cache_head *new, struct cache_head *old, int hash)
140{
141 /* The 'old' entry is to be replaced by 'new'.
142 * If 'old' is not VALID, we update it directly,
143 * otherwise we need to replace it
144 */
145 struct cache_head **head;
146 struct cache_head *tmp;
147
148 if (!test_bit(CACHE_VALID, &old->flags)) {
149 write_lock(&detail->hash_lock);
150 if (!test_bit(CACHE_VALID, &old->flags)) {
151 if (test_bit(CACHE_NEGATIVE, &new->flags))
152 set_bit(CACHE_NEGATIVE, &old->flags);
153 else
154 detail->update(old, new);
NeilBrown908329f2009-09-09 16:32:54 +1000155 cache_fresh_locked(old, new->expiry_time);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800156 write_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000157 cache_fresh_unlocked(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800158 return old;
159 }
160 write_unlock(&detail->hash_lock);
161 }
162 /* We need to insert a new entry */
163 tmp = detail->alloc();
164 if (!tmp) {
NeilBrownbaab9352006-03-27 01:15:09 -0800165 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800166 return NULL;
167 }
168 cache_init(tmp);
169 detail->init(tmp, old);
170 head = &detail->hash_table[hash];
171
172 write_lock(&detail->hash_lock);
173 if (test_bit(CACHE_NEGATIVE, &new->flags))
174 set_bit(CACHE_NEGATIVE, &tmp->flags);
175 else
176 detail->update(tmp, new);
177 tmp->next = *head;
178 *head = tmp;
NeilBrownf2d39582006-05-22 22:35:25 -0700179 detail->entries++;
NeilBrown15a5f6b2006-03-27 01:15:02 -0800180 cache_get(tmp);
NeilBrown908329f2009-09-09 16:32:54 +1000181 cache_fresh_locked(tmp, new->expiry_time);
NeilBrownebd0cb12006-03-27 01:15:08 -0800182 cache_fresh_locked(old, 0);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800183 write_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000184 cache_fresh_unlocked(tmp, detail);
185 cache_fresh_unlocked(old, detail);
NeilBrownbaab9352006-03-27 01:15:09 -0800186 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800187 return tmp;
188}
Trond Myklebust24c37672008-12-23 16:30:12 -0500189EXPORT_SYMBOL_GPL(sunrpc_cache_update);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
Trond Myklebustbc74b4f2009-08-09 15:14:29 -0400191static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
192{
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +0300193 if (cd->cache_upcall)
194 return cd->cache_upcall(cd, h);
Stanislav Kinsbursky21cd1252013-02-04 14:02:55 +0300195 return sunrpc_cache_pipe_upcall(cd, h);
Trond Myklebustbc74b4f2009-08-09 15:14:29 -0400196}
NeilBrown989a19b2009-08-04 15:22:38 +1000197
chaoting fanb6040f92013-03-28 22:19:45 +0800198static inline int cache_is_valid(struct cache_head *h)
NeilBrown989a19b2009-08-04 15:22:38 +1000199{
NeilBrownd202cce2010-02-03 17:31:31 +1100200 if (!test_bit(CACHE_VALID, &h->flags))
NeilBrown989a19b2009-08-04 15:22:38 +1000201 return -EAGAIN;
202 else {
203 /* entry is valid */
204 if (test_bit(CACHE_NEGATIVE, &h->flags))
205 return -ENOENT;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500206 else {
207 /*
208 * In combination with write barrier in
209 * sunrpc_cache_update, ensures that anyone
210 * using the cache entry after this sees the
211 * updated contents:
212 */
213 smp_rmb();
NeilBrown989a19b2009-08-04 15:22:38 +1000214 return 0;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500215 }
NeilBrown989a19b2009-08-04 15:22:38 +1000216 }
217}
J. Bruce Fieldse9dc1222009-08-21 11:27:29 -0400218
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500219static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
220{
221 int rv;
222
223 write_lock(&detail->hash_lock);
chaoting fanb6040f92013-03-28 22:19:45 +0800224 rv = cache_is_valid(h);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000225 if (rv == -EAGAIN) {
226 set_bit(CACHE_NEGATIVE, &h->flags);
227 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY);
228 rv = -ENOENT;
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500229 }
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500230 write_unlock(&detail->hash_lock);
231 cache_fresh_unlocked(h, detail);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000232 return rv;
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500233}
234
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235/*
236 * This is the generic cache management routine for all
237 * the authentication caches.
238 * It checks the currency of a cache item and will (later)
239 * initiate an upcall to fill it if needed.
240 *
241 *
242 * Returns 0 if the cache_head can be used, or cache_puts it and returns
NeilBrown989a19b2009-08-04 15:22:38 +1000243 * -EAGAIN if upcall is pending and request has been queued
244 * -ETIMEDOUT if upcall failed or request could not be queue or
245 * upcall completed but item is still invalid (implying that
246 * the cache item has been replaced with a newer one).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 * -ENOENT if cache entry was negative
248 */
249int cache_check(struct cache_detail *detail,
250 struct cache_head *h, struct cache_req *rqstp)
251{
252 int rv;
253 long refresh_age, age;
254
255 /* First decide return status as best we can */
chaoting fanb6040f92013-03-28 22:19:45 +0800256 rv = cache_is_valid(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 /* now see if we want to start an upcall */
259 refresh_age = (h->expiry_time - h->last_refresh);
NeilBrownc5b29f82010-08-12 16:55:22 +1000260 age = seconds_since_boot() - h->last_refresh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
262 if (rqstp == NULL) {
263 if (rv == -EAGAIN)
264 rv = -ENOENT;
NeilBrown0bebc6332013-06-13 12:53:42 +1000265 } else if (rv == -EAGAIN ||
266 (h->expiry_time != 0 && age > refresh_age/2)) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500267 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
268 refresh_age, age);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
270 switch (cache_make_upcall(detail, h)) {
271 case -EINVAL:
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500272 rv = try_to_negate_entry(detail, h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 case -EAGAIN:
NeilBrown2a1c7f52013-06-13 12:53:42 +1000275 cache_fresh_unlocked(h, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 break;
277 }
278 }
279 }
280
NeilBrown989a19b2009-08-04 15:22:38 +1000281 if (rv == -EAGAIN) {
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500282 if (!cache_defer_req(rqstp, h)) {
283 /*
284 * Request was not deferred; handle it as best
285 * we can ourselves:
286 */
chaoting fanb6040f92013-03-28 22:19:45 +0800287 rv = cache_is_valid(h);
NeilBrown989a19b2009-08-04 15:22:38 +1000288 if (rv == -EAGAIN)
289 rv = -ETIMEDOUT;
290 }
291 }
NeilBrown4013ede2006-03-27 01:15:07 -0800292 if (rv)
NeilBrownbaab9352006-03-27 01:15:09 -0800293 cache_put(h, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 return rv;
295}
Trond Myklebust24c37672008-12-23 16:30:12 -0500296EXPORT_SYMBOL_GPL(cache_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298/*
299 * caches need to be periodically cleaned.
300 * For this we maintain a list of cache_detail and
301 * a current pointer into that list and into the table
302 * for that entry.
303 *
NeilBrown013920e2013-06-13 12:53:42 +1000304 * Each time cache_clean is called it finds the next non-empty entry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 * in the current table and walks the list in that entry
306 * looking for entries that can be removed.
307 *
308 * An entry gets removed if:
309 * - The expiry is before current time
310 * - The last_refresh time is before the flush_time for that cache
311 *
312 * later we might drop old entries with non-NEVER expiry if that table
313 * is getting 'full' for some definition of 'full'
314 *
315 * The question of "how often to scan a table" is an interesting one
316 * and is answered in part by the use of the "nextcheck" field in the
317 * cache_detail.
318 * When a scan of a table begins, the nextcheck field is set to a time
319 * that is well into the future.
320 * While scanning, if an expiry time is found that is earlier than the
321 * current nextcheck time, nextcheck is set to that expiry time.
322 * If the flush_time is ever set to a time earlier than the nextcheck
323 * time, the nextcheck time is then set to that flush_time.
324 *
325 * A table is then only scanned if the current time is at least
326 * the nextcheck time.
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800327 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 */
329
330static LIST_HEAD(cache_list);
331static DEFINE_SPINLOCK(cache_list_lock);
332static struct cache_detail *current_detail;
333static int current_index;
334
David Howells65f27f32006-11-22 14:55:48 +0000335static void do_cache_clean(struct work_struct *work);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +0300336static struct delayed_work cache_cleaner;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300338void sunrpc_init_cache_detail(struct cache_detail *cd)
J. Bruce Fieldsffe93862007-11-12 17:04:29 -0500339{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 rwlock_init(&cd->hash_lock);
341 INIT_LIST_HEAD(&cd->queue);
342 spin_lock(&cache_list_lock);
343 cd->nextcheck = 0;
344 cd->entries = 0;
345 atomic_set(&cd->readers, 0);
346 cd->last_close = 0;
347 cd->last_warn = -1;
348 list_add(&cd->others, &cache_list);
349 spin_unlock(&cache_list_lock);
350
351 /* start the cleaning process */
David Howells52bad642006-11-22 14:54:01 +0000352 schedule_delayed_work(&cache_cleaner, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300354EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300356void sunrpc_destroy_cache_detail(struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357{
358 cache_purge(cd);
359 spin_lock(&cache_list_lock);
360 write_lock(&cd->hash_lock);
361 if (cd->entries || atomic_read(&cd->inuse)) {
362 write_unlock(&cd->hash_lock);
363 spin_unlock(&cache_list_lock);
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500364 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 }
366 if (current_detail == cd)
367 current_detail = NULL;
368 list_del_init(&cd->others);
369 write_unlock(&cd->hash_lock);
370 spin_unlock(&cache_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 if (list_empty(&cache_list)) {
372 /* module must be being unloaded so its safe to kill the worker */
Trond Myklebust4011cd92007-08-07 15:33:01 -0400373 cancel_delayed_work_sync(&cache_cleaner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 }
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500375 return;
376out:
377 printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300379EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
381/* clean cache tries to find something to clean
382 * and cleans it.
383 * It returns 1 if it cleaned something,
384 * 0 if it didn't find anything this time
385 * -1 if it fell off the end of the list.
386 */
387static int cache_clean(void)
388{
389 int rv = 0;
390 struct list_head *next;
391
392 spin_lock(&cache_list_lock);
393
394 /* find a suitable table if we don't already have one */
395 while (current_detail == NULL ||
396 current_index >= current_detail->hash_size) {
397 if (current_detail)
398 next = current_detail->others.next;
399 else
400 next = cache_list.next;
401 if (next == &cache_list) {
402 current_detail = NULL;
403 spin_unlock(&cache_list_lock);
404 return -1;
405 }
406 current_detail = list_entry(next, struct cache_detail, others);
NeilBrownc5b29f82010-08-12 16:55:22 +1000407 if (current_detail->nextcheck > seconds_since_boot())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 current_index = current_detail->hash_size;
409 else {
410 current_index = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +1000411 current_detail->nextcheck = seconds_since_boot()+30*60;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 }
413 }
414
415 /* find a non-empty bucket in the table */
416 while (current_detail &&
417 current_index < current_detail->hash_size &&
418 current_detail->hash_table[current_index] == NULL)
419 current_index++;
420
421 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800422
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 if (current_detail && current_index < current_detail->hash_size) {
424 struct cache_head *ch, **cp;
425 struct cache_detail *d;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800426
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 write_lock(&current_detail->hash_lock);
428
429 /* Ok, now to clean this strand */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 cp = & current_detail->hash_table[current_index];
NeilBrown3af49742010-02-03 17:31:31 +1100432 for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 if (current_detail->nextcheck > ch->expiry_time)
434 current_detail->nextcheck = ch->expiry_time+1;
NeilBrown2f50d8b2010-02-03 17:31:31 +1100435 if (!cache_is_expired(current_detail, ch))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 *cp = ch->next;
439 ch->next = NULL;
440 current_detail->entries--;
441 rv = 1;
NeilBrown3af49742010-02-03 17:31:31 +1100442 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 }
NeilBrown3af49742010-02-03 17:31:31 +1100444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 write_unlock(&current_detail->hash_lock);
446 d = current_detail;
447 if (!ch)
448 current_index ++;
449 spin_unlock(&cache_list_lock);
NeilBrown5c4d2632009-08-04 15:22:38 +1000450 if (ch) {
NeilBrown013920e2013-06-13 12:53:42 +1000451 set_bit(CACHE_CLEANED, &ch->flags);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000452 cache_fresh_unlocked(ch, d);
NeilBrownbaab9352006-03-27 01:15:09 -0800453 cache_put(ch, d);
NeilBrown5c4d2632009-08-04 15:22:38 +1000454 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 } else
456 spin_unlock(&cache_list_lock);
457
458 return rv;
459}
460
461/*
462 * We want to regularly clean the cache, so we need to schedule some work ...
463 */
David Howells65f27f32006-11-22 14:55:48 +0000464static void do_cache_clean(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465{
466 int delay = 5;
467 if (cache_clean() == -1)
Anton Blanchard6aad89c2009-06-10 12:52:21 -0700468 delay = round_jiffies_relative(30*HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
470 if (list_empty(&cache_list))
471 delay = 0;
472
473 if (delay)
474 schedule_delayed_work(&cache_cleaner, delay);
475}
476
477
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800478/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 * Clean all caches promptly. This just calls cache_clean
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800480 * repeatedly until we are sure that every cache has had a chance to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 * be fully cleaned
482 */
483void cache_flush(void)
484{
485 while (cache_clean() != -1)
486 cond_resched();
487 while (cache_clean() != -1)
488 cond_resched();
489}
Trond Myklebust24c37672008-12-23 16:30:12 -0500490EXPORT_SYMBOL_GPL(cache_flush);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
492void cache_purge(struct cache_detail *detail)
493{
494 detail->flush_time = LONG_MAX;
NeilBrownc5b29f82010-08-12 16:55:22 +1000495 detail->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 cache_flush();
497 detail->flush_time = 1;
498}
Trond Myklebust24c37672008-12-23 16:30:12 -0500499EXPORT_SYMBOL_GPL(cache_purge);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
501
502/*
503 * Deferral and Revisiting of Requests.
504 *
505 * If a cache lookup finds a pending entry, we
506 * need to defer the request and revisit it later.
507 * All deferred requests are stored in a hash table,
508 * indexed by "struct cache_head *".
509 * As it may be wasteful to store a whole request
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800510 * structure, we allow the request to provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 * deferred form, which must contain a
512 * 'struct cache_deferred_req'
513 * This cache_deferred_req contains a method to allow
514 * it to be revisited when cache info is available
515 */
516
517#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
518#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
519
520#define DFR_MAX 300 /* ??? */
521
522static DEFINE_SPINLOCK(cache_defer_lock);
523static LIST_HEAD(cache_defer_list);
NeilBrown11174492010-08-12 17:04:08 +1000524static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525static int cache_defer_cnt;
526
J. Bruce Fields6610f722010-08-26 13:19:52 -0400527static void __unhash_deferred_req(struct cache_deferred_req *dreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528{
NeilBrown11174492010-08-12 17:04:08 +1000529 hlist_del_init(&dreq->hash);
NeilBrowne33534d2010-10-07 15:29:46 +1100530 if (!list_empty(&dreq->recent)) {
531 list_del_init(&dreq->recent);
532 cache_defer_cnt--;
533 }
J. Bruce Fields6610f722010-08-26 13:19:52 -0400534}
535
536static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
537{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 int hash = DFR_HASH(item);
539
NeilBrowne33534d2010-10-07 15:29:46 +1100540 INIT_LIST_HEAD(&dreq->recent);
NeilBrown11174492010-08-12 17:04:08 +1000541 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
J. Bruce Fields6610f722010-08-26 13:19:52 -0400542}
543
NeilBrowne33534d2010-10-07 15:29:46 +1100544static void setup_deferral(struct cache_deferred_req *dreq,
545 struct cache_head *item,
546 int count_me)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
549 dreq->item = item;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
551 spin_lock(&cache_defer_lock);
552
J. Bruce Fields6610f722010-08-26 13:19:52 -0400553 __hash_deferred_req(dreq, item);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
NeilBrowne33534d2010-10-07 15:29:46 +1100555 if (count_me) {
556 cache_defer_cnt++;
557 list_add(&dreq->recent, &cache_defer_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 }
NeilBrowne33534d2010-10-07 15:29:46 +1100559
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 spin_unlock(&cache_defer_lock);
561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
J. Bruce Fields3211af12010-08-26 16:56:23 -0400564struct thread_deferred_req {
565 struct cache_deferred_req handle;
566 struct completion completion;
567};
568
569static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
570{
571 struct thread_deferred_req *dr =
572 container_of(dreq, struct thread_deferred_req, handle);
573 complete(&dr->completion);
574}
575
NeilBrownd29068c42010-10-07 15:29:46 +1100576static void cache_wait_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400577{
578 struct thread_deferred_req sleeper;
579 struct cache_deferred_req *dreq = &sleeper.handle;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400580
581 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
582 dreq->revisit = cache_restart_thread;
583
NeilBrowne33534d2010-10-07 15:29:46 +1100584 setup_deferral(dreq, item, 0);
J. Bruce Fields3211af12010-08-26 16:56:23 -0400585
NeilBrownd29068c42010-10-07 15:29:46 +1100586 if (!test_bit(CACHE_PENDING, &item->flags) ||
NeilBrown277f68d2010-09-22 12:55:06 +1000587 wait_for_completion_interruptible_timeout(
J. Bruce Fields3211af12010-08-26 16:56:23 -0400588 &sleeper.completion, req->thread_wait) <= 0) {
589 /* The completion wasn't completed, so we need
590 * to clean up
591 */
592 spin_lock(&cache_defer_lock);
NeilBrown11174492010-08-12 17:04:08 +1000593 if (!hlist_unhashed(&sleeper.handle.hash)) {
J. Bruce Fields3211af12010-08-26 16:56:23 -0400594 __unhash_deferred_req(&sleeper.handle);
595 spin_unlock(&cache_defer_lock);
596 } else {
597 /* cache_revisit_request already removed
598 * this from the hash table, but hasn't
599 * called ->revisit yet. It will very soon
600 * and we need to wait for it.
601 */
602 spin_unlock(&cache_defer_lock);
603 wait_for_completion(&sleeper.completion);
604 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 }
J. Bruce Fields3211af12010-08-26 16:56:23 -0400606}
607
NeilBrowne33534d2010-10-07 15:29:46 +1100608static void cache_limit_defers(void)
609{
610 /* Make sure we haven't exceed the limit of allowed deferred
611 * requests.
612 */
613 struct cache_deferred_req *discard = NULL;
614
615 if (cache_defer_cnt <= DFR_MAX)
616 return;
617
618 spin_lock(&cache_defer_lock);
619
620 /* Consider removing either the first or the last */
621 if (cache_defer_cnt > DFR_MAX) {
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -0500622 if (prandom_u32() & 1)
NeilBrowne33534d2010-10-07 15:29:46 +1100623 discard = list_entry(cache_defer_list.next,
624 struct cache_deferred_req, recent);
625 else
626 discard = list_entry(cache_defer_list.prev,
627 struct cache_deferred_req, recent);
628 __unhash_deferred_req(discard);
629 }
630 spin_unlock(&cache_defer_lock);
631 if (discard)
632 discard->revisit(discard, 1);
633}
634
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500635/* Return true if and only if a deferred request is queued. */
636static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400637{
638 struct cache_deferred_req *dreq;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400639
J. Bruce Fields3211af12010-08-26 16:56:23 -0400640 if (req->thread_wait) {
NeilBrownd29068c42010-10-07 15:29:46 +1100641 cache_wait_req(req, item);
642 if (!test_bit(CACHE_PENDING, &item->flags))
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500643 return false;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400644 }
645 dreq = req->defer(req);
646 if (dreq == NULL)
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500647 return false;
NeilBrowne33534d2010-10-07 15:29:46 +1100648 setup_deferral(dreq, item, 1);
NeilBrownd29068c42010-10-07 15:29:46 +1100649 if (!test_bit(CACHE_PENDING, &item->flags))
650 /* Bit could have been cleared before we managed to
651 * set up the deferral, so need to revisit just in case
652 */
653 cache_revisit_request(item);
NeilBrowne33534d2010-10-07 15:29:46 +1100654
655 cache_limit_defers();
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500656 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657}
658
659static void cache_revisit_request(struct cache_head *item)
660{
661 struct cache_deferred_req *dreq;
662 struct list_head pending;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800663 struct hlist_node *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 int hash = DFR_HASH(item);
665
666 INIT_LIST_HEAD(&pending);
667 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800668
Sasha Levinb67bfe02013-02-27 17:06:00 -0800669 hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash)
NeilBrown11174492010-08-12 17:04:08 +1000670 if (dreq->item == item) {
671 __unhash_deferred_req(dreq);
672 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 }
NeilBrown11174492010-08-12 17:04:08 +1000674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 spin_unlock(&cache_defer_lock);
676
677 while (!list_empty(&pending)) {
678 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
679 list_del_init(&dreq->recent);
680 dreq->revisit(dreq, 0);
681 }
682}
683
684void cache_clean_deferred(void *owner)
685{
686 struct cache_deferred_req *dreq, *tmp;
687 struct list_head pending;
688
689
690 INIT_LIST_HEAD(&pending);
691 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800692
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
694 if (dreq->owner == owner) {
J. Bruce Fields6610f722010-08-26 13:19:52 -0400695 __unhash_deferred_req(dreq);
NeilBrowne95dffa2010-09-22 12:55:06 +1000696 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 }
698 }
699 spin_unlock(&cache_defer_lock);
700
701 while (!list_empty(&pending)) {
702 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
703 list_del_init(&dreq->recent);
704 dreq->revisit(dreq, 1);
705 }
706}
707
708/*
709 * communicate with user-space
710 *
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500711 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
712 * On read, you get a full request, or block.
713 * On write, an update request is processed.
714 * Poll works if anything to read, and always allows write.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800716 * Implemented by linked list of requests. Each open file has
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500717 * a ->private that also exists in this list. New requests are added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 * to the end and may wakeup and preceding readers.
719 * New readers are added to the head. If, on read, an item is found with
720 * CACHE_UPCALLING clear, we free it from the list.
721 *
722 */
723
724static DEFINE_SPINLOCK(queue_lock);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800725static DEFINE_MUTEX(queue_io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
727struct cache_queue {
728 struct list_head list;
729 int reader; /* if 0, then request */
730};
731struct cache_request {
732 struct cache_queue q;
733 struct cache_head *item;
734 char * buf;
735 int len;
736 int readers;
737};
738struct cache_reader {
739 struct cache_queue q;
740 int offset; /* if non-0, we have a refcnt on next request */
741};
742
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +0300743static int cache_request(struct cache_detail *detail,
744 struct cache_request *crq)
745{
746 char *bp = crq->buf;
747 int len = PAGE_SIZE;
748
749 detail->cache_request(detail, crq->item, &bp, &len);
750 if (len < 0)
751 return -EAGAIN;
752 return PAGE_SIZE - len;
753}
754
Trond Myklebust173912a2009-08-09 15:14:29 -0400755static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
756 loff_t *ppos, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757{
758 struct cache_reader *rp = filp->private_data;
759 struct cache_request *rq;
Al Viro496ad9a2013-01-23 17:07:38 -0500760 struct inode *inode = file_inode(filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 int err;
762
763 if (count == 0)
764 return 0;
765
Trond Myklebustda770052009-08-09 15:14:28 -0400766 mutex_lock(&inode->i_mutex); /* protect against multiple concurrent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 * readers on this file */
768 again:
769 spin_lock(&queue_lock);
770 /* need to find next request */
771 while (rp->q.list.next != &cd->queue &&
772 list_entry(rp->q.list.next, struct cache_queue, list)
773 ->reader) {
774 struct list_head *next = rp->q.list.next;
775 list_move(&rp->q.list, next);
776 }
777 if (rp->q.list.next == &cd->queue) {
778 spin_unlock(&queue_lock);
Trond Myklebustda770052009-08-09 15:14:28 -0400779 mutex_unlock(&inode->i_mutex);
Weston Andros Adamson0db74d92012-10-23 10:43:36 -0400780 WARN_ON_ONCE(rp->offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 return 0;
782 }
783 rq = container_of(rp->q.list.next, struct cache_request, q.list);
Weston Andros Adamson0db74d92012-10-23 10:43:36 -0400784 WARN_ON_ONCE(rq->q.reader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 if (rp->offset == 0)
786 rq->readers++;
787 spin_unlock(&queue_lock);
788
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +0300789 if (rq->len == 0) {
790 err = cache_request(cd, rq);
791 if (err < 0)
792 goto out;
793 rq->len = err;
794 }
795
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
797 err = -EAGAIN;
798 spin_lock(&queue_lock);
799 list_move(&rp->q.list, &rq->q.list);
800 spin_unlock(&queue_lock);
801 } else {
802 if (rp->offset + count > rq->len)
803 count = rq->len - rp->offset;
804 err = -EFAULT;
805 if (copy_to_user(buf, rq->buf + rp->offset, count))
806 goto out;
807 rp->offset += count;
808 if (rp->offset >= rq->len) {
809 rp->offset = 0;
810 spin_lock(&queue_lock);
811 list_move(&rp->q.list, &rq->q.list);
812 spin_unlock(&queue_lock);
813 }
814 err = 0;
815 }
816 out:
817 if (rp->offset == 0) {
818 /* need to release rq */
819 spin_lock(&queue_lock);
820 rq->readers--;
821 if (rq->readers == 0 &&
822 !test_bit(CACHE_PENDING, &rq->item->flags)) {
823 list_del(&rq->q.list);
824 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800825 cache_put(rq->item, cd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 kfree(rq->buf);
827 kfree(rq);
828 } else
829 spin_unlock(&queue_lock);
830 }
831 if (err == -EAGAIN)
832 goto again;
Trond Myklebustda770052009-08-09 15:14:28 -0400833 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 return err ? err : count;
835}
836
Trond Myklebustda770052009-08-09 15:14:28 -0400837static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
838 size_t count, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839{
Trond Myklebustda770052009-08-09 15:14:28 -0400840 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841
Dan Carpenter6d8d1742012-01-18 12:56:02 +0300842 if (count == 0)
843 return -EINVAL;
Trond Myklebustda770052009-08-09 15:14:28 -0400844 if (copy_from_user(kaddr, buf, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 return -EFAULT;
Trond Myklebustda770052009-08-09 15:14:28 -0400846 kaddr[count] = '\0';
847 ret = cd->cache_parse(cd, kaddr, count);
848 if (!ret)
849 ret = count;
850 return ret;
851}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Trond Myklebustda770052009-08-09 15:14:28 -0400853static ssize_t cache_slow_downcall(const char __user *buf,
854 size_t count, struct cache_detail *cd)
855{
856 static char write_buf[8192]; /* protected by queue_io_mutex */
857 ssize_t ret = -EINVAL;
858
859 if (count >= sizeof(write_buf))
860 goto out;
861 mutex_lock(&queue_io_mutex);
862 ret = cache_do_downcall(write_buf, buf, count, cd);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800863 mutex_unlock(&queue_io_mutex);
Trond Myklebustda770052009-08-09 15:14:28 -0400864out:
865 return ret;
866}
867
868static ssize_t cache_downcall(struct address_space *mapping,
869 const char __user *buf,
870 size_t count, struct cache_detail *cd)
871{
872 struct page *page;
873 char *kaddr;
874 ssize_t ret = -ENOMEM;
875
876 if (count >= PAGE_CACHE_SIZE)
877 goto out_slow;
878
879 page = find_or_create_page(mapping, 0, GFP_KERNEL);
880 if (!page)
881 goto out_slow;
882
883 kaddr = kmap(page);
884 ret = cache_do_downcall(kaddr, buf, count, cd);
885 kunmap(page);
886 unlock_page(page);
887 page_cache_release(page);
888 return ret;
889out_slow:
890 return cache_slow_downcall(buf, count, cd);
891}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
Trond Myklebust173912a2009-08-09 15:14:29 -0400893static ssize_t cache_write(struct file *filp, const char __user *buf,
894 size_t count, loff_t *ppos,
895 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896{
Trond Myklebustda770052009-08-09 15:14:28 -0400897 struct address_space *mapping = filp->f_mapping;
Al Viro496ad9a2013-01-23 17:07:38 -0500898 struct inode *inode = file_inode(filp);
Trond Myklebustda770052009-08-09 15:14:28 -0400899 ssize_t ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
Trond Myklebustda770052009-08-09 15:14:28 -0400901 if (!cd->cache_parse)
902 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
Trond Myklebustda770052009-08-09 15:14:28 -0400904 mutex_lock(&inode->i_mutex);
905 ret = cache_downcall(mapping, buf, count, cd);
906 mutex_unlock(&inode->i_mutex);
907out:
908 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909}
910
911static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
912
Trond Myklebust173912a2009-08-09 15:14:29 -0400913static unsigned int cache_poll(struct file *filp, poll_table *wait,
914 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915{
916 unsigned int mask;
917 struct cache_reader *rp = filp->private_data;
918 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919
920 poll_wait(filp, &queue_wait, wait);
921
922 /* alway allow write */
923 mask = POLL_OUT | POLLWRNORM;
924
925 if (!rp)
926 return mask;
927
928 spin_lock(&queue_lock);
929
930 for (cq= &rp->q; &cq->list != &cd->queue;
931 cq = list_entry(cq->list.next, struct cache_queue, list))
932 if (!cq->reader) {
933 mask |= POLLIN | POLLRDNORM;
934 break;
935 }
936 spin_unlock(&queue_lock);
937 return mask;
938}
939
Trond Myklebust173912a2009-08-09 15:14:29 -0400940static int cache_ioctl(struct inode *ino, struct file *filp,
941 unsigned int cmd, unsigned long arg,
942 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943{
944 int len = 0;
945 struct cache_reader *rp = filp->private_data;
946 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947
948 if (cmd != FIONREAD || !rp)
949 return -EINVAL;
950
951 spin_lock(&queue_lock);
952
953 /* only find the length remaining in current request,
954 * or the length of the next request
955 */
956 for (cq= &rp->q; &cq->list != &cd->queue;
957 cq = list_entry(cq->list.next, struct cache_queue, list))
958 if (!cq->reader) {
959 struct cache_request *cr =
960 container_of(cq, struct cache_request, q);
961 len = cr->len - rp->offset;
962 break;
963 }
964 spin_unlock(&queue_lock);
965
966 return put_user(len, (int __user *)arg);
967}
968
Trond Myklebust173912a2009-08-09 15:14:29 -0400969static int cache_open(struct inode *inode, struct file *filp,
970 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971{
972 struct cache_reader *rp = NULL;
973
Trond Myklebustf7e86ab2009-08-19 18:13:00 -0400974 if (!cd || !try_module_get(cd->owner))
975 return -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 nonseekable_open(inode, filp);
977 if (filp->f_mode & FMODE_READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
Alexey Khoroshilova7823c72013-03-23 00:36:44 +0400979 if (!rp) {
980 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 return -ENOMEM;
Alexey Khoroshilova7823c72013-03-23 00:36:44 +0400982 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 rp->offset = 0;
984 rp->q.reader = 1;
985 atomic_inc(&cd->readers);
986 spin_lock(&queue_lock);
987 list_add(&rp->q.list, &cd->queue);
988 spin_unlock(&queue_lock);
989 }
990 filp->private_data = rp;
991 return 0;
992}
993
Trond Myklebust173912a2009-08-09 15:14:29 -0400994static int cache_release(struct inode *inode, struct file *filp,
995 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996{
997 struct cache_reader *rp = filp->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998
999 if (rp) {
1000 spin_lock(&queue_lock);
1001 if (rp->offset) {
1002 struct cache_queue *cq;
1003 for (cq= &rp->q; &cq->list != &cd->queue;
1004 cq = list_entry(cq->list.next, struct cache_queue, list))
1005 if (!cq->reader) {
1006 container_of(cq, struct cache_request, q)
1007 ->readers--;
1008 break;
1009 }
1010 rp->offset = 0;
1011 }
1012 list_del(&rp->q.list);
1013 spin_unlock(&queue_lock);
1014
1015 filp->private_data = NULL;
1016 kfree(rp);
1017
NeilBrownc5b29f82010-08-12 16:55:22 +10001018 cd->last_close = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 atomic_dec(&cd->readers);
1020 }
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001021 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022 return 0;
1023}
1024
1025
1026
NeilBrownf866a812009-08-04 15:22:38 +10001027static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028{
NeilBrownf9e1aed2013-06-13 12:53:42 +10001029 struct cache_queue *cq, *tmp;
1030 struct cache_request *cr;
1031 struct list_head dequeued;
1032
1033 INIT_LIST_HEAD(&dequeued);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 spin_lock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001035 list_for_each_entry_safe(cq, tmp, &detail->queue, list)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 if (!cq->reader) {
NeilBrownf9e1aed2013-06-13 12:53:42 +10001037 cr = container_of(cq, struct cache_request, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 if (cr->item != ch)
1039 continue;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001040 if (test_bit(CACHE_PENDING, &ch->flags))
1041 /* Lost a race and it is pending again */
1042 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 if (cr->readers != 0)
NeilBrown4013ede2006-03-27 01:15:07 -08001044 continue;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001045 list_move(&cr->q.list, &dequeued);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 }
1047 spin_unlock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001048 while (!list_empty(&dequeued)) {
1049 cr = list_entry(dequeued.next, struct cache_request, q.list);
1050 list_del(&cr->q.list);
1051 cache_put(cr->item, detail);
1052 kfree(cr->buf);
1053 kfree(cr);
1054 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055}
1056
1057/*
1058 * Support routines for text-based upcalls.
1059 * Fields are separated by spaces.
1060 * Fields are either mangled to quote space tab newline slosh with slosh
1061 * or a hexified with a leading \x
1062 * Record is terminated with newline.
1063 *
1064 */
1065
1066void qword_add(char **bpp, int *lp, char *str)
1067{
1068 char *bp = *bpp;
1069 int len = *lp;
1070 char c;
1071
1072 if (len < 0) return;
1073
1074 while ((c=*str++) && len)
1075 switch(c) {
1076 case ' ':
1077 case '\t':
1078 case '\n':
1079 case '\\':
1080 if (len >= 4) {
1081 *bp++ = '\\';
1082 *bp++ = '0' + ((c & 0300)>>6);
1083 *bp++ = '0' + ((c & 0070)>>3);
1084 *bp++ = '0' + ((c & 0007)>>0);
1085 }
1086 len -= 4;
1087 break;
1088 default:
1089 *bp++ = c;
1090 len--;
1091 }
1092 if (c || len <1) len = -1;
1093 else {
1094 *bp++ = ' ';
1095 len--;
1096 }
1097 *bpp = bp;
1098 *lp = len;
1099}
Trond Myklebust24c37672008-12-23 16:30:12 -05001100EXPORT_SYMBOL_GPL(qword_add);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101
1102void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1103{
1104 char *bp = *bpp;
1105 int len = *lp;
1106
1107 if (len < 0) return;
1108
1109 if (len > 2) {
1110 *bp++ = '\\';
1111 *bp++ = 'x';
1112 len -= 2;
1113 while (blen && len >= 2) {
Andy Shevchenko056785e2013-12-12 15:49:21 +02001114 bp = hex_byte_pack(bp, *buf++);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 len -= 2;
1116 blen--;
1117 }
1118 }
1119 if (blen || len<1) len = -1;
1120 else {
1121 *bp++ = ' ';
1122 len--;
1123 }
1124 *bpp = bp;
1125 *lp = len;
1126}
Trond Myklebust24c37672008-12-23 16:30:12 -05001127EXPORT_SYMBOL_GPL(qword_addhex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128
1129static void warn_no_listener(struct cache_detail *detail)
1130{
1131 if (detail->last_warn != detail->last_close) {
1132 detail->last_warn = detail->last_close;
1133 if (detail->warn_no_listener)
Trond Myklebust2da8ca22009-08-09 15:14:26 -04001134 detail->warn_no_listener(detail, detail->last_close != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 }
1136}
1137
J. Bruce Fields06497522010-09-19 22:55:06 -04001138static bool cache_listeners_exist(struct cache_detail *detail)
1139{
1140 if (atomic_read(&detail->readers))
1141 return true;
1142 if (detail->last_close == 0)
1143 /* This cache was never opened */
1144 return false;
1145 if (detail->last_close < seconds_since_boot() - 30)
1146 /*
1147 * We allow for the possibility that someone might
1148 * restart a userspace daemon without restarting the
1149 * server; but after 30 seconds, we give up.
1150 */
1151 return false;
1152 return true;
1153}
1154
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155/*
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001156 * register an upcall request to user-space and queue it up for read() by the
1157 * upcall daemon.
1158 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 * Each request is at most one page long.
1160 */
Stanislav Kinsbursky21cd1252013-02-04 14:02:55 +03001161int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162{
1163
1164 char *buf;
1165 struct cache_request *crq;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001166 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +03001168 if (!detail->cache_request)
1169 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170
J. Bruce Fields06497522010-09-19 22:55:06 -04001171 if (!cache_listeners_exist(detail)) {
1172 warn_no_listener(detail);
1173 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 }
NeilBrown013920e2013-06-13 12:53:42 +10001175 if (test_bit(CACHE_CLEANED, &h->flags))
1176 /* Too late to make an upcall */
1177 return -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178
1179 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1180 if (!buf)
1181 return -EAGAIN;
1182
1183 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1184 if (!crq) {
1185 kfree(buf);
1186 return -EAGAIN;
1187 }
1188
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 crq->q.reader = 0;
1190 crq->item = cache_get(h);
1191 crq->buf = buf;
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +03001192 crq->len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 crq->readers = 0;
1194 spin_lock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001195 if (test_bit(CACHE_PENDING, &h->flags))
1196 list_add_tail(&crq->q.list, &detail->queue);
1197 else
1198 /* Lost a race, no longer PENDING, so don't enqueue */
1199 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200 spin_unlock(&queue_lock);
1201 wake_up(&queue_wait);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001202 if (ret == -EAGAIN) {
1203 kfree(buf);
1204 kfree(crq);
1205 }
1206 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207}
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001208EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209
1210/*
1211 * parse a message from user-space and pass it
1212 * to an appropriate cache
1213 * Messages are, like requests, separated into fields by
1214 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1215 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001216 * Message is
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 * reply cachename expiry key ... content....
1218 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001219 * key and content are both parsed by cache
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 */
1221
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222int qword_get(char **bpp, char *dest, int bufsize)
1223{
1224 /* return bytes copied, or -1 on error */
1225 char *bp = *bpp;
1226 int len = 0;
1227
1228 while (*bp == ' ') bp++;
1229
1230 if (bp[0] == '\\' && bp[1] == 'x') {
1231 /* HEX STRING */
1232 bp += 2;
Andy Shevchenkoe7f483e2010-09-21 09:40:25 +03001233 while (len < bufsize) {
1234 int h, l;
1235
1236 h = hex_to_bin(bp[0]);
1237 if (h < 0)
1238 break;
1239
1240 l = hex_to_bin(bp[1]);
1241 if (l < 0)
1242 break;
1243
1244 *dest++ = (h << 4) | l;
1245 bp += 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 len++;
1247 }
1248 } else {
1249 /* text with \nnn octal quoting */
1250 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1251 if (*bp == '\\' &&
1252 isodigit(bp[1]) && (bp[1] <= '3') &&
1253 isodigit(bp[2]) &&
1254 isodigit(bp[3])) {
1255 int byte = (*++bp -'0');
1256 bp++;
1257 byte = (byte << 3) | (*bp++ - '0');
1258 byte = (byte << 3) | (*bp++ - '0');
1259 *dest++ = byte;
1260 len++;
1261 } else {
1262 *dest++ = *bp++;
1263 len++;
1264 }
1265 }
1266 }
1267
1268 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1269 return -1;
1270 while (*bp == ' ') bp++;
1271 *bpp = bp;
1272 *dest = '\0';
1273 return len;
1274}
Trond Myklebust24c37672008-12-23 16:30:12 -05001275EXPORT_SYMBOL_GPL(qword_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276
1277
1278/*
1279 * support /proc/sunrpc/cache/$CACHENAME/content
1280 * as a seqfile.
1281 * We call ->cache_show passing NULL for the item to
1282 * get a header, then pass each real item in the cache
1283 */
1284
1285struct handle {
1286 struct cache_detail *cd;
1287};
1288
1289static void *c_start(struct seq_file *m, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001290 __acquires(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291{
1292 loff_t n = *pos;
Eric Dumazet95c96172012-04-15 05:58:06 +00001293 unsigned int hash, entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 struct cache_head *ch;
1295 struct cache_detail *cd = ((struct handle*)m->private)->cd;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001296
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297
1298 read_lock(&cd->hash_lock);
1299 if (!n--)
1300 return SEQ_START_TOKEN;
1301 hash = n >> 32;
1302 entry = n & ((1LL<<32) - 1);
1303
1304 for (ch=cd->hash_table[hash]; ch; ch=ch->next)
1305 if (!entry--)
1306 return ch;
1307 n &= ~((1LL<<32) - 1);
1308 do {
1309 hash++;
1310 n += 1LL<<32;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001311 } while(hash < cd->hash_size &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 cd->hash_table[hash]==NULL);
1313 if (hash >= cd->hash_size)
1314 return NULL;
1315 *pos = n+1;
1316 return cd->hash_table[hash];
1317}
1318
1319static void *c_next(struct seq_file *m, void *p, loff_t *pos)
1320{
1321 struct cache_head *ch = p;
1322 int hash = (*pos >> 32);
1323 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1324
1325 if (p == SEQ_START_TOKEN)
1326 hash = 0;
1327 else if (ch->next == NULL) {
1328 hash++;
1329 *pos += 1LL<<32;
1330 } else {
1331 ++*pos;
1332 return ch->next;
1333 }
1334 *pos &= ~((1LL<<32) - 1);
1335 while (hash < cd->hash_size &&
1336 cd->hash_table[hash] == NULL) {
1337 hash++;
1338 *pos += 1LL<<32;
1339 }
1340 if (hash >= cd->hash_size)
1341 return NULL;
1342 ++*pos;
1343 return cd->hash_table[hash];
1344}
1345
1346static void c_stop(struct seq_file *m, void *p)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001347 __releases(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348{
1349 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1350 read_unlock(&cd->hash_lock);
1351}
1352
1353static int c_show(struct seq_file *m, void *p)
1354{
1355 struct cache_head *cp = p;
1356 struct cache_detail *cd = ((struct handle*)m->private)->cd;
1357
1358 if (p == SEQ_START_TOKEN)
1359 return cd->cache_show(m, cd, NULL);
1360
1361 ifdebug(CACHE)
NeilBrown4013ede2006-03-27 01:15:07 -08001362 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
NeilBrownc5b29f82010-08-12 16:55:22 +10001363 convert_to_wallclock(cp->expiry_time),
1364 atomic_read(&cp->ref.refcount), cp->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 cache_get(cp);
1366 if (cache_check(cd, cp, NULL))
1367 /* cache_check does a cache_put on failure */
1368 seq_printf(m, "# ");
NeilBrown200724a2012-07-12 10:37:34 +10001369 else {
1370 if (cache_is_expired(cd, cp))
1371 seq_printf(m, "# ");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372 cache_put(cp, cd);
NeilBrown200724a2012-07-12 10:37:34 +10001373 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374
1375 return cd->cache_show(m, cd, cp);
1376}
1377
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001378static const struct seq_operations cache_content_op = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379 .start = c_start,
1380 .next = c_next,
1381 .stop = c_stop,
1382 .show = c_show,
1383};
1384
Trond Myklebust173912a2009-08-09 15:14:29 -04001385static int content_open(struct inode *inode, struct file *file,
1386 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 struct handle *han;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001390 if (!cd || !try_module_get(cd->owner))
1391 return -EACCES;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001392 han = __seq_open_private(file, &cache_content_op, sizeof(*han));
Li Zefana5990ea2010-03-11 14:08:10 -08001393 if (han == NULL) {
1394 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 return -ENOMEM;
Li Zefana5990ea2010-03-11 14:08:10 -08001396 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397
1398 han->cd = cd;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001399 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001402static int content_release(struct inode *inode, struct file *file,
1403 struct cache_detail *cd)
1404{
1405 int ret = seq_release_private(inode, file);
1406 module_put(cd->owner);
1407 return ret;
1408}
1409
1410static int open_flush(struct inode *inode, struct file *file,
1411 struct cache_detail *cd)
1412{
1413 if (!cd || !try_module_get(cd->owner))
1414 return -EACCES;
1415 return nonseekable_open(inode, file);
1416}
1417
1418static int release_flush(struct inode *inode, struct file *file,
1419 struct cache_detail *cd)
1420{
1421 module_put(cd->owner);
1422 return 0;
1423}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424
1425static ssize_t read_flush(struct file *file, char __user *buf,
Trond Myklebust173912a2009-08-09 15:14:29 -04001426 size_t count, loff_t *ppos,
1427 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428{
Sasha Levin212ba902012-07-17 00:01:26 +02001429 char tbuf[22];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 unsigned long p = *ppos;
Chuck Lever01b29692007-10-26 13:31:20 -04001431 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432
Sasha Levin212ba902012-07-17 00:01:26 +02001433 snprintf(tbuf, sizeof(tbuf), "%lu\n", convert_to_wallclock(cd->flush_time));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 len = strlen(tbuf);
1435 if (p >= len)
1436 return 0;
1437 len -= p;
Chuck Lever01b29692007-10-26 13:31:20 -04001438 if (len > count)
1439 len = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 if (copy_to_user(buf, (void*)(tbuf+p), len))
Chuck Lever01b29692007-10-26 13:31:20 -04001441 return -EFAULT;
1442 *ppos += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 return len;
1444}
1445
Trond Myklebust173912a2009-08-09 15:14:29 -04001446static ssize_t write_flush(struct file *file, const char __user *buf,
1447 size_t count, loff_t *ppos,
1448 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450 char tbuf[20];
NeilBrownc5b29f82010-08-12 16:55:22 +10001451 char *bp, *ep;
1452
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453 if (*ppos || count > sizeof(tbuf)-1)
1454 return -EINVAL;
1455 if (copy_from_user(tbuf, buf, count))
1456 return -EFAULT;
1457 tbuf[count] = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +10001458 simple_strtoul(tbuf, &ep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459 if (*ep && *ep != '\n')
1460 return -EINVAL;
1461
NeilBrownc5b29f82010-08-12 16:55:22 +10001462 bp = tbuf;
1463 cd->flush_time = get_expiry(&bp);
1464 cd->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465 cache_flush();
1466
1467 *ppos += count;
1468 return count;
1469}
1470
Trond Myklebust173912a2009-08-09 15:14:29 -04001471static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1472 size_t count, loff_t *ppos)
1473{
Al Virod9dda782013-03-31 18:16:14 -04001474 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001475
1476 return cache_read(filp, buf, count, ppos, cd);
1477}
1478
1479static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1480 size_t count, loff_t *ppos)
1481{
Al Virod9dda782013-03-31 18:16:14 -04001482 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001483
1484 return cache_write(filp, buf, count, ppos, cd);
1485}
1486
1487static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1488{
Al Virod9dda782013-03-31 18:16:14 -04001489 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001490
1491 return cache_poll(filp, wait, cd);
1492}
1493
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001494static long cache_ioctl_procfs(struct file *filp,
1495 unsigned int cmd, unsigned long arg)
Trond Myklebust173912a2009-08-09 15:14:29 -04001496{
Al Viro496ad9a2013-01-23 17:07:38 -05001497 struct inode *inode = file_inode(filp);
Al Virod9dda782013-03-31 18:16:14 -04001498 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001499
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001500 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001501}
1502
1503static int cache_open_procfs(struct inode *inode, struct file *filp)
1504{
Al Virod9dda782013-03-31 18:16:14 -04001505 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001506
1507 return cache_open(inode, filp, cd);
1508}
1509
1510static int cache_release_procfs(struct inode *inode, struct file *filp)
1511{
Al Virod9dda782013-03-31 18:16:14 -04001512 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001513
1514 return cache_release(inode, filp, cd);
1515}
1516
1517static const struct file_operations cache_file_operations_procfs = {
1518 .owner = THIS_MODULE,
1519 .llseek = no_llseek,
1520 .read = cache_read_procfs,
1521 .write = cache_write_procfs,
1522 .poll = cache_poll_procfs,
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001523 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
Trond Myklebust173912a2009-08-09 15:14:29 -04001524 .open = cache_open_procfs,
1525 .release = cache_release_procfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526};
Trond Myklebust173912a2009-08-09 15:14:29 -04001527
1528static int content_open_procfs(struct inode *inode, struct file *filp)
1529{
Al Virod9dda782013-03-31 18:16:14 -04001530 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001531
1532 return content_open(inode, filp, cd);
1533}
1534
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001535static int content_release_procfs(struct inode *inode, struct file *filp)
1536{
Al Virod9dda782013-03-31 18:16:14 -04001537 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001538
1539 return content_release(inode, filp, cd);
1540}
1541
Trond Myklebust173912a2009-08-09 15:14:29 -04001542static const struct file_operations content_file_operations_procfs = {
1543 .open = content_open_procfs,
1544 .read = seq_read,
1545 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001546 .release = content_release_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001547};
1548
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001549static int open_flush_procfs(struct inode *inode, struct file *filp)
1550{
Al Virod9dda782013-03-31 18:16:14 -04001551 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001552
1553 return open_flush(inode, filp, cd);
1554}
1555
1556static int release_flush_procfs(struct inode *inode, struct file *filp)
1557{
Al Virod9dda782013-03-31 18:16:14 -04001558 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001559
1560 return release_flush(inode, filp, cd);
1561}
1562
Trond Myklebust173912a2009-08-09 15:14:29 -04001563static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1564 size_t count, loff_t *ppos)
1565{
Al Virod9dda782013-03-31 18:16:14 -04001566 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001567
1568 return read_flush(filp, buf, count, ppos, cd);
1569}
1570
1571static ssize_t write_flush_procfs(struct file *filp,
1572 const char __user *buf,
1573 size_t count, loff_t *ppos)
1574{
Al Virod9dda782013-03-31 18:16:14 -04001575 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001576
1577 return write_flush(filp, buf, count, ppos, cd);
1578}
1579
1580static const struct file_operations cache_flush_operations_procfs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001581 .open = open_flush_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001582 .read = read_flush_procfs,
1583 .write = write_flush_procfs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001584 .release = release_flush_procfs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001585 .llseek = no_llseek,
Trond Myklebust173912a2009-08-09 15:14:29 -04001586};
1587
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001588static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001589{
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001590 struct sunrpc_net *sn;
1591
Trond Myklebust173912a2009-08-09 15:14:29 -04001592 if (cd->u.procfs.proc_ent == NULL)
1593 return;
1594 if (cd->u.procfs.flush_ent)
1595 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1596 if (cd->u.procfs.channel_ent)
1597 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1598 if (cd->u.procfs.content_ent)
1599 remove_proc_entry("content", cd->u.procfs.proc_ent);
1600 cd->u.procfs.proc_ent = NULL;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001601 sn = net_generic(net, sunrpc_net_id);
1602 remove_proc_entry(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001603}
1604
1605#ifdef CONFIG_PROC_FS
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001606static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001607{
1608 struct proc_dir_entry *p;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001609 struct sunrpc_net *sn;
Trond Myklebust173912a2009-08-09 15:14:29 -04001610
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001611 sn = net_generic(net, sunrpc_net_id);
1612 cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001613 if (cd->u.procfs.proc_ent == NULL)
1614 goto out_nomem;
1615 cd->u.procfs.channel_ent = NULL;
1616 cd->u.procfs.content_ent = NULL;
1617
1618 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1619 cd->u.procfs.proc_ent,
1620 &cache_flush_operations_procfs, cd);
1621 cd->u.procfs.flush_ent = p;
1622 if (p == NULL)
1623 goto out_nomem;
1624
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +03001625 if (cd->cache_request || cd->cache_parse) {
Trond Myklebust173912a2009-08-09 15:14:29 -04001626 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1627 cd->u.procfs.proc_ent,
1628 &cache_file_operations_procfs, cd);
1629 cd->u.procfs.channel_ent = p;
1630 if (p == NULL)
1631 goto out_nomem;
1632 }
1633 if (cd->cache_show) {
Yanchuan Nianec168672013-01-04 19:45:35 +08001634 p = proc_create_data("content", S_IFREG|S_IRUSR,
Trond Myklebust173912a2009-08-09 15:14:29 -04001635 cd->u.procfs.proc_ent,
1636 &content_file_operations_procfs, cd);
1637 cd->u.procfs.content_ent = p;
1638 if (p == NULL)
1639 goto out_nomem;
1640 }
1641 return 0;
1642out_nomem:
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001643 remove_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001644 return -ENOMEM;
1645}
1646#else /* CONFIG_PROC_FS */
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001647static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001648{
1649 return 0;
1650}
1651#endif
1652
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001653void __init cache_initialize(void)
1654{
Tejun Heo203b42f2012-08-21 13:18:23 -07001655 INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001656}
1657
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001658int cache_register_net(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001659{
1660 int ret;
1661
1662 sunrpc_init_cache_detail(cd);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001663 ret = create_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001664 if (ret)
1665 sunrpc_destroy_cache_detail(cd);
1666 return ret;
1667}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001668EXPORT_SYMBOL_GPL(cache_register_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001669
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001670void cache_unregister_net(struct cache_detail *cd, struct net *net)
1671{
1672 remove_cache_proc_entries(cd, net);
1673 sunrpc_destroy_cache_detail(cd);
1674}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001675EXPORT_SYMBOL_GPL(cache_unregister_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001676
Stanislav Kinsbursky0a402d52012-01-19 21:42:21 +04001677struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001678{
Stanislav Kinsbursky0a402d52012-01-19 21:42:21 +04001679 struct cache_detail *cd;
1680
1681 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
1682 if (cd == NULL)
1683 return ERR_PTR(-ENOMEM);
1684
1685 cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *),
1686 GFP_KERNEL);
1687 if (cd->hash_table == NULL) {
1688 kfree(cd);
1689 return ERR_PTR(-ENOMEM);
1690 }
1691 cd->net = net;
1692 return cd;
Trond Myklebust173912a2009-08-09 15:14:29 -04001693}
Stanislav Kinsbursky0a402d52012-01-19 21:42:21 +04001694EXPORT_SYMBOL_GPL(cache_create_net);
1695
1696void cache_destroy_net(struct cache_detail *cd, struct net *net)
1697{
1698 kfree(cd->hash_table);
1699 kfree(cd);
1700}
1701EXPORT_SYMBOL_GPL(cache_destroy_net);
Trond Myklebust8854e822009-08-09 15:14:30 -04001702
1703static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1704 size_t count, loff_t *ppos)
1705{
Al Viro496ad9a2013-01-23 17:07:38 -05001706 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001707
1708 return cache_read(filp, buf, count, ppos, cd);
1709}
1710
1711static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1712 size_t count, loff_t *ppos)
1713{
Al Viro496ad9a2013-01-23 17:07:38 -05001714 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001715
1716 return cache_write(filp, buf, count, ppos, cd);
1717}
1718
1719static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1720{
Al Viro496ad9a2013-01-23 17:07:38 -05001721 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001722
1723 return cache_poll(filp, wait, cd);
1724}
1725
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001726static long cache_ioctl_pipefs(struct file *filp,
Trond Myklebust8854e822009-08-09 15:14:30 -04001727 unsigned int cmd, unsigned long arg)
1728{
Al Viro496ad9a2013-01-23 17:07:38 -05001729 struct inode *inode = file_inode(filp);
Trond Myklebust8854e822009-08-09 15:14:30 -04001730 struct cache_detail *cd = RPC_I(inode)->private;
1731
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001732 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust8854e822009-08-09 15:14:30 -04001733}
1734
1735static int cache_open_pipefs(struct inode *inode, struct file *filp)
1736{
1737 struct cache_detail *cd = RPC_I(inode)->private;
1738
1739 return cache_open(inode, filp, cd);
1740}
1741
1742static int cache_release_pipefs(struct inode *inode, struct file *filp)
1743{
1744 struct cache_detail *cd = RPC_I(inode)->private;
1745
1746 return cache_release(inode, filp, cd);
1747}
1748
1749const struct file_operations cache_file_operations_pipefs = {
1750 .owner = THIS_MODULE,
1751 .llseek = no_llseek,
1752 .read = cache_read_pipefs,
1753 .write = cache_write_pipefs,
1754 .poll = cache_poll_pipefs,
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001755 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
Trond Myklebust8854e822009-08-09 15:14:30 -04001756 .open = cache_open_pipefs,
1757 .release = cache_release_pipefs,
1758};
1759
1760static int content_open_pipefs(struct inode *inode, struct file *filp)
1761{
1762 struct cache_detail *cd = RPC_I(inode)->private;
1763
1764 return content_open(inode, filp, cd);
1765}
1766
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001767static int content_release_pipefs(struct inode *inode, struct file *filp)
1768{
1769 struct cache_detail *cd = RPC_I(inode)->private;
1770
1771 return content_release(inode, filp, cd);
1772}
1773
Trond Myklebust8854e822009-08-09 15:14:30 -04001774const struct file_operations content_file_operations_pipefs = {
1775 .open = content_open_pipefs,
1776 .read = seq_read,
1777 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001778 .release = content_release_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001779};
1780
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001781static int open_flush_pipefs(struct inode *inode, struct file *filp)
1782{
1783 struct cache_detail *cd = RPC_I(inode)->private;
1784
1785 return open_flush(inode, filp, cd);
1786}
1787
1788static int release_flush_pipefs(struct inode *inode, struct file *filp)
1789{
1790 struct cache_detail *cd = RPC_I(inode)->private;
1791
1792 return release_flush(inode, filp, cd);
1793}
1794
Trond Myklebust8854e822009-08-09 15:14:30 -04001795static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1796 size_t count, loff_t *ppos)
1797{
Al Viro496ad9a2013-01-23 17:07:38 -05001798 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001799
1800 return read_flush(filp, buf, count, ppos, cd);
1801}
1802
1803static ssize_t write_flush_pipefs(struct file *filp,
1804 const char __user *buf,
1805 size_t count, loff_t *ppos)
1806{
Al Viro496ad9a2013-01-23 17:07:38 -05001807 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001808
1809 return write_flush(filp, buf, count, ppos, cd);
1810}
1811
1812const struct file_operations cache_flush_operations_pipefs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001813 .open = open_flush_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001814 .read = read_flush_pipefs,
1815 .write = write_flush_pipefs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001816 .release = release_flush_pipefs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001817 .llseek = no_llseek,
Trond Myklebust8854e822009-08-09 15:14:30 -04001818};
1819
1820int sunrpc_cache_register_pipefs(struct dentry *parent,
Al Viro64f14262011-07-25 00:35:13 -04001821 const char *name, umode_t umode,
Trond Myklebust8854e822009-08-09 15:14:30 -04001822 struct cache_detail *cd)
1823{
Al Viroa95e6912013-07-14 16:43:54 +04001824 struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd);
1825 if (IS_ERR(dir))
1826 return PTR_ERR(dir);
1827 cd->u.pipefs.dir = dir;
1828 return 0;
Trond Myklebust8854e822009-08-09 15:14:30 -04001829}
1830EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1831
1832void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1833{
1834 rpc_remove_cache_dir(cd->u.pipefs.dir);
1835 cd->u.pipefs.dir = NULL;
Trond Myklebust8854e822009-08-09 15:14:30 -04001836}
1837EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
1838