blob: 553bf95f700301a4821d4317e9277f784370bd22 [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>
Andy Shevchenko1b2e1222014-11-28 17:50:28 +020023#include <linux/string_helpers.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/uaccess.h>
25#include <linux/poll.h>
26#include <linux/seq_file.h>
27#include <linux/proc_fs.h>
28#include <linux/net.h>
29#include <linux/workqueue.h>
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080030#include <linux/mutex.h>
Trond Myklebustda770052009-08-09 15:14:28 -040031#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <asm/ioctls.h>
33#include <linux/sunrpc/types.h>
34#include <linux/sunrpc/cache.h>
35#include <linux/sunrpc/stats.h>
Trond Myklebust8854e822009-08-09 15:14:30 -040036#include <linux/sunrpc/rpc_pipe_fs.h>
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +040037#include "netns.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#define RPCDBG_FACILITY RPCDBG_CACHE
40
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -050041static bool cache_defer_req(struct cache_req *req, struct cache_head *item);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042static void cache_revisit_request(struct cache_head *item);
43
Neil Brown77862032015-10-16 08:59:08 +110044static void cache_init(struct cache_head *h, struct cache_detail *detail)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
NeilBrownc5b29f82010-08-12 16:55:22 +100046 time_t now = seconds_since_boot();
Kinglong Mee129e5822015-07-27 11:10:15 +080047 INIT_HLIST_NODE(&h->cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 h->flags = 0;
NeilBrownbaab9352006-03-27 01:15:09 -080049 kref_init(&h->ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 h->expiry_time = now + CACHE_NEW_EXPIRY;
Neil Brown77862032015-10-16 08:59:08 +110051 if (now <= detail->flush_time)
52 /* ensure it isn't already expired */
53 now = detail->flush_time + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 h->last_refresh = now;
55}
56
NeilBrown15a5f6b2006-03-27 01:15:02 -080057struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
58 struct cache_head *key, int hash)
59{
Kinglong Mee129e5822015-07-27 11:10:15 +080060 struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL;
61 struct hlist_head *head;
NeilBrown15a5f6b2006-03-27 01:15:02 -080062
63 head = &detail->hash_table[hash];
64
65 read_lock(&detail->hash_lock);
66
Kinglong Mee129e5822015-07-27 11:10:15 +080067 hlist_for_each_entry(tmp, head, cache_list) {
NeilBrown15a5f6b2006-03-27 01:15:02 -080068 if (detail->match(tmp, key)) {
NeilBrownd202cce2010-02-03 17:31:31 +110069 if (cache_is_expired(detail, tmp))
70 /* This entry is expired, we will discard it. */
71 break;
NeilBrown15a5f6b2006-03-27 01:15:02 -080072 cache_get(tmp);
73 read_unlock(&detail->hash_lock);
74 return tmp;
75 }
76 }
77 read_unlock(&detail->hash_lock);
78 /* Didn't find anything, insert an empty entry */
79
80 new = detail->alloc();
81 if (!new)
82 return NULL;
Neil Brown2f349312006-08-05 12:14:29 -070083 /* must fully initialise 'new', else
84 * we might get lose if we need to
85 * cache_put it soon.
86 */
Neil Brown77862032015-10-16 08:59:08 +110087 cache_init(new, detail);
Neil Brown2f349312006-08-05 12:14:29 -070088 detail->init(new, key);
NeilBrown15a5f6b2006-03-27 01:15:02 -080089
90 write_lock(&detail->hash_lock);
91
92 /* check if entry appeared while we slept */
Kinglong Mee129e5822015-07-27 11:10:15 +080093 hlist_for_each_entry(tmp, head, cache_list) {
NeilBrown15a5f6b2006-03-27 01:15:02 -080094 if (detail->match(tmp, key)) {
NeilBrownd202cce2010-02-03 17:31:31 +110095 if (cache_is_expired(detail, tmp)) {
Kinglong Mee129e5822015-07-27 11:10:15 +080096 hlist_del_init(&tmp->cache_list);
NeilBrownd202cce2010-02-03 17:31:31 +110097 detail->entries --;
98 freeme = tmp;
99 break;
100 }
NeilBrown15a5f6b2006-03-27 01:15:02 -0800101 cache_get(tmp);
102 write_unlock(&detail->hash_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800103 cache_put(new, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800104 return tmp;
105 }
106 }
Kinglong Mee129e5822015-07-27 11:10:15 +0800107
108 hlist_add_head(&new->cache_list, head);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800109 detail->entries++;
110 cache_get(new);
111 write_unlock(&detail->hash_lock);
112
NeilBrownd202cce2010-02-03 17:31:31 +1100113 if (freeme)
114 cache_put(freeme, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800115 return new;
116}
Trond Myklebust24c37672008-12-23 16:30:12 -0500117EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800118
NeilBrownebd0cb12006-03-27 01:15:08 -0800119
NeilBrownf866a812009-08-04 15:22:38 +1000120static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
NeilBrownebd0cb12006-03-27 01:15:08 -0800121
Neil Brown77862032015-10-16 08:59:08 +1100122static void cache_fresh_locked(struct cache_head *head, time_t expiry,
123 struct cache_detail *detail)
NeilBrownebd0cb12006-03-27 01:15:08 -0800124{
Neil Brown77862032015-10-16 08:59:08 +1100125 time_t now = seconds_since_boot();
126 if (now <= detail->flush_time)
127 /* ensure it isn't immediately treated as expired */
128 now = detail->flush_time + 1;
NeilBrownebd0cb12006-03-27 01:15:08 -0800129 head->expiry_time = expiry;
Neil Brown77862032015-10-16 08:59:08 +1100130 head->last_refresh = now;
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 */
NeilBrown15a5f6b2006-03-27 01:15:02 -0800151 struct cache_head *tmp;
152
153 if (!test_bit(CACHE_VALID, &old->flags)) {
154 write_lock(&detail->hash_lock);
155 if (!test_bit(CACHE_VALID, &old->flags)) {
156 if (test_bit(CACHE_NEGATIVE, &new->flags))
157 set_bit(CACHE_NEGATIVE, &old->flags);
158 else
159 detail->update(old, new);
Neil Brown77862032015-10-16 08:59:08 +1100160 cache_fresh_locked(old, new->expiry_time, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800161 write_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000162 cache_fresh_unlocked(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800163 return old;
164 }
165 write_unlock(&detail->hash_lock);
166 }
167 /* We need to insert a new entry */
168 tmp = detail->alloc();
169 if (!tmp) {
NeilBrownbaab9352006-03-27 01:15:09 -0800170 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800171 return NULL;
172 }
Neil Brown77862032015-10-16 08:59:08 +1100173 cache_init(tmp, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800174 detail->init(tmp, old);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800175
176 write_lock(&detail->hash_lock);
177 if (test_bit(CACHE_NEGATIVE, &new->flags))
178 set_bit(CACHE_NEGATIVE, &tmp->flags);
179 else
180 detail->update(tmp, new);
Kinglong Mee129e5822015-07-27 11:10:15 +0800181 hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
NeilBrownf2d39582006-05-22 22:35:25 -0700182 detail->entries++;
NeilBrown15a5f6b2006-03-27 01:15:02 -0800183 cache_get(tmp);
Neil Brown77862032015-10-16 08:59:08 +1100184 cache_fresh_locked(tmp, new->expiry_time, detail);
185 cache_fresh_locked(old, 0, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800186 write_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000187 cache_fresh_unlocked(tmp, detail);
188 cache_fresh_unlocked(old, detail);
NeilBrownbaab9352006-03-27 01:15:09 -0800189 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800190 return tmp;
191}
Trond Myklebust24c37672008-12-23 16:30:12 -0500192EXPORT_SYMBOL_GPL(sunrpc_cache_update);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
Trond Myklebustbc74b4f2009-08-09 15:14:29 -0400194static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
195{
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +0300196 if (cd->cache_upcall)
197 return cd->cache_upcall(cd, h);
Stanislav Kinsbursky21cd1252013-02-04 14:02:55 +0300198 return sunrpc_cache_pipe_upcall(cd, h);
Trond Myklebustbc74b4f2009-08-09 15:14:29 -0400199}
NeilBrown989a19b2009-08-04 15:22:38 +1000200
chaoting fanb6040f972013-03-28 22:19:45 +0800201static inline int cache_is_valid(struct cache_head *h)
NeilBrown989a19b2009-08-04 15:22:38 +1000202{
NeilBrownd202cce2010-02-03 17:31:31 +1100203 if (!test_bit(CACHE_VALID, &h->flags))
NeilBrown989a19b2009-08-04 15:22:38 +1000204 return -EAGAIN;
205 else {
206 /* entry is valid */
207 if (test_bit(CACHE_NEGATIVE, &h->flags))
208 return -ENOENT;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500209 else {
210 /*
211 * In combination with write barrier in
212 * sunrpc_cache_update, ensures that anyone
213 * using the cache entry after this sees the
214 * updated contents:
215 */
216 smp_rmb();
NeilBrown989a19b2009-08-04 15:22:38 +1000217 return 0;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500218 }
NeilBrown989a19b2009-08-04 15:22:38 +1000219 }
220}
J. Bruce Fieldse9dc1222009-08-21 11:27:29 -0400221
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500222static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
223{
224 int rv;
225
226 write_lock(&detail->hash_lock);
chaoting fanb6040f972013-03-28 22:19:45 +0800227 rv = cache_is_valid(h);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000228 if (rv == -EAGAIN) {
229 set_bit(CACHE_NEGATIVE, &h->flags);
Neil Brown77862032015-10-16 08:59:08 +1100230 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
231 detail);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000232 rv = -ENOENT;
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500233 }
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500234 write_unlock(&detail->hash_lock);
235 cache_fresh_unlocked(h, detail);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000236 return rv;
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500237}
238
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239/*
240 * This is the generic cache management routine for all
241 * the authentication caches.
242 * It checks the currency of a cache item and will (later)
243 * initiate an upcall to fill it if needed.
244 *
245 *
246 * Returns 0 if the cache_head can be used, or cache_puts it and returns
NeilBrown989a19b2009-08-04 15:22:38 +1000247 * -EAGAIN if upcall is pending and request has been queued
248 * -ETIMEDOUT if upcall failed or request could not be queue or
249 * upcall completed but item is still invalid (implying that
250 * the cache item has been replaced with a newer one).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 * -ENOENT if cache entry was negative
252 */
253int cache_check(struct cache_detail *detail,
254 struct cache_head *h, struct cache_req *rqstp)
255{
256 int rv;
257 long refresh_age, age;
258
259 /* First decide return status as best we can */
chaoting fanb6040f972013-03-28 22:19:45 +0800260 rv = cache_is_valid(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
262 /* now see if we want to start an upcall */
263 refresh_age = (h->expiry_time - h->last_refresh);
NeilBrownc5b29f82010-08-12 16:55:22 +1000264 age = seconds_since_boot() - h->last_refresh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266 if (rqstp == NULL) {
267 if (rv == -EAGAIN)
268 rv = -ENOENT;
NeilBrown0bebc632013-06-13 12:53:42 +1000269 } else if (rv == -EAGAIN ||
270 (h->expiry_time != 0 && age > refresh_age/2)) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500271 dprintk("RPC: Want update, refage=%ld, age=%ld\n",
272 refresh_age, age);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
274 switch (cache_make_upcall(detail, h)) {
275 case -EINVAL:
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500276 rv = try_to_negate_entry(detail, h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 case -EAGAIN:
NeilBrown2a1c7f52013-06-13 12:53:42 +1000279 cache_fresh_unlocked(h, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 break;
281 }
282 }
283 }
284
NeilBrown989a19b2009-08-04 15:22:38 +1000285 if (rv == -EAGAIN) {
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500286 if (!cache_defer_req(rqstp, h)) {
287 /*
288 * Request was not deferred; handle it as best
289 * we can ourselves:
290 */
chaoting fanb6040f972013-03-28 22:19:45 +0800291 rv = cache_is_valid(h);
NeilBrown989a19b2009-08-04 15:22:38 +1000292 if (rv == -EAGAIN)
293 rv = -ETIMEDOUT;
294 }
295 }
NeilBrown4013ede2006-03-27 01:15:07 -0800296 if (rv)
NeilBrownbaab9352006-03-27 01:15:09 -0800297 cache_put(h, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 return rv;
299}
Trond Myklebust24c37672008-12-23 16:30:12 -0500300EXPORT_SYMBOL_GPL(cache_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302/*
303 * caches need to be periodically cleaned.
304 * For this we maintain a list of cache_detail and
305 * a current pointer into that list and into the table
306 * for that entry.
307 *
NeilBrown013920e2013-06-13 12:53:42 +1000308 * Each time cache_clean is called it finds the next non-empty entry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 * in the current table and walks the list in that entry
310 * looking for entries that can be removed.
311 *
312 * An entry gets removed if:
313 * - The expiry is before current time
314 * - The last_refresh time is before the flush_time for that cache
315 *
316 * later we might drop old entries with non-NEVER expiry if that table
317 * is getting 'full' for some definition of 'full'
318 *
319 * The question of "how often to scan a table" is an interesting one
320 * and is answered in part by the use of the "nextcheck" field in the
321 * cache_detail.
322 * When a scan of a table begins, the nextcheck field is set to a time
323 * that is well into the future.
324 * While scanning, if an expiry time is found that is earlier than the
325 * current nextcheck time, nextcheck is set to that expiry time.
326 * If the flush_time is ever set to a time earlier than the nextcheck
327 * time, the nextcheck time is then set to that flush_time.
328 *
329 * A table is then only scanned if the current time is at least
330 * the nextcheck time.
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800331 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 */
333
334static LIST_HEAD(cache_list);
335static DEFINE_SPINLOCK(cache_list_lock);
336static struct cache_detail *current_detail;
337static int current_index;
338
David Howells65f27f32006-11-22 14:55:48 +0000339static void do_cache_clean(struct work_struct *work);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +0300340static struct delayed_work cache_cleaner;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300342void sunrpc_init_cache_detail(struct cache_detail *cd)
J. Bruce Fieldsffe93862007-11-12 17:04:29 -0500343{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 rwlock_init(&cd->hash_lock);
345 INIT_LIST_HEAD(&cd->queue);
346 spin_lock(&cache_list_lock);
347 cd->nextcheck = 0;
348 cd->entries = 0;
349 atomic_set(&cd->readers, 0);
350 cd->last_close = 0;
351 cd->last_warn = -1;
352 list_add(&cd->others, &cache_list);
353 spin_unlock(&cache_list_lock);
354
355 /* start the cleaning process */
David Howells52bad642006-11-22 14:54:01 +0000356 schedule_delayed_work(&cache_cleaner, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300358EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300360void sunrpc_destroy_cache_detail(struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361{
362 cache_purge(cd);
363 spin_lock(&cache_list_lock);
364 write_lock(&cd->hash_lock);
365 if (cd->entries || atomic_read(&cd->inuse)) {
366 write_unlock(&cd->hash_lock);
367 spin_unlock(&cache_list_lock);
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500368 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 }
370 if (current_detail == cd)
371 current_detail = NULL;
372 list_del_init(&cd->others);
373 write_unlock(&cd->hash_lock);
374 spin_unlock(&cache_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 if (list_empty(&cache_list)) {
376 /* module must be being unloaded so its safe to kill the worker */
Trond Myklebust4011cd92007-08-07 15:33:01 -0400377 cancel_delayed_work_sync(&cache_cleaner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 }
J. Bruce Fieldsdf95a9d2007-11-08 16:09:59 -0500379 return;
380out:
Kinglong Meeecca0632014-04-15 17:13:56 +0800381 printk(KERN_ERR "RPC: failed to unregister %s cache\n", cd->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300383EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
385/* clean cache tries to find something to clean
386 * and cleans it.
387 * It returns 1 if it cleaned something,
388 * 0 if it didn't find anything this time
389 * -1 if it fell off the end of the list.
390 */
391static int cache_clean(void)
392{
393 int rv = 0;
394 struct list_head *next;
395
396 spin_lock(&cache_list_lock);
397
398 /* find a suitable table if we don't already have one */
399 while (current_detail == NULL ||
400 current_index >= current_detail->hash_size) {
401 if (current_detail)
402 next = current_detail->others.next;
403 else
404 next = cache_list.next;
405 if (next == &cache_list) {
406 current_detail = NULL;
407 spin_unlock(&cache_list_lock);
408 return -1;
409 }
410 current_detail = list_entry(next, struct cache_detail, others);
NeilBrownc5b29f82010-08-12 16:55:22 +1000411 if (current_detail->nextcheck > seconds_since_boot())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 current_index = current_detail->hash_size;
413 else {
414 current_index = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +1000415 current_detail->nextcheck = seconds_since_boot()+30*60;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 }
417 }
418
419 /* find a non-empty bucket in the table */
420 while (current_detail &&
421 current_index < current_detail->hash_size &&
Kinglong Mee129e5822015-07-27 11:10:15 +0800422 hlist_empty(&current_detail->hash_table[current_index]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 current_index++;
424
425 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800426
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 if (current_detail && current_index < current_detail->hash_size) {
Kinglong Mee129e5822015-07-27 11:10:15 +0800428 struct cache_head *ch = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 struct cache_detail *d;
Kinglong Mee129e5822015-07-27 11:10:15 +0800430 struct hlist_head *head;
431 struct hlist_node *tmp;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800432
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 write_lock(&current_detail->hash_lock);
434
435 /* Ok, now to clean this strand */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800436
Kinglong Mee129e5822015-07-27 11:10:15 +0800437 head = &current_detail->hash_table[current_index];
438 hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 if (current_detail->nextcheck > ch->expiry_time)
440 current_detail->nextcheck = ch->expiry_time+1;
NeilBrown2f50d8b2010-02-03 17:31:31 +1100441 if (!cache_is_expired(current_detail, ch))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443
Kinglong Mee129e5822015-07-27 11:10:15 +0800444 hlist_del_init(&ch->cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 current_detail->entries--;
446 rv = 1;
NeilBrown3af49742010-02-03 17:31:31 +1100447 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 }
NeilBrown3af49742010-02-03 17:31:31 +1100449
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 write_unlock(&current_detail->hash_lock);
451 d = current_detail;
452 if (!ch)
453 current_index ++;
454 spin_unlock(&cache_list_lock);
NeilBrown5c4d2632009-08-04 15:22:38 +1000455 if (ch) {
NeilBrown013920e2013-06-13 12:53:42 +1000456 set_bit(CACHE_CLEANED, &ch->flags);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000457 cache_fresh_unlocked(ch, d);
NeilBrownbaab9352006-03-27 01:15:09 -0800458 cache_put(ch, d);
NeilBrown5c4d2632009-08-04 15:22:38 +1000459 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 } else
461 spin_unlock(&cache_list_lock);
462
463 return rv;
464}
465
466/*
467 * We want to regularly clean the cache, so we need to schedule some work ...
468 */
David Howells65f27f32006-11-22 14:55:48 +0000469static void do_cache_clean(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470{
471 int delay = 5;
472 if (cache_clean() == -1)
Anton Blanchard6aad89c2009-06-10 12:52:21 -0700473 delay = round_jiffies_relative(30*HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474
475 if (list_empty(&cache_list))
476 delay = 0;
477
478 if (delay)
479 schedule_delayed_work(&cache_cleaner, delay);
480}
481
482
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800483/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 * Clean all caches promptly. This just calls cache_clean
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800485 * repeatedly until we are sure that every cache has had a chance to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 * be fully cleaned
487 */
488void cache_flush(void)
489{
490 while (cache_clean() != -1)
491 cond_resched();
492 while (cache_clean() != -1)
493 cond_resched();
494}
Trond Myklebust24c37672008-12-23 16:30:12 -0500495EXPORT_SYMBOL_GPL(cache_flush);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
497void cache_purge(struct cache_detail *detail)
498{
Neil Brown77862032015-10-16 08:59:08 +1100499 time_t now = seconds_since_boot();
500 if (detail->flush_time >= now)
501 now = detail->flush_time + 1;
502 /* 'now' is the maximum value any 'last_refresh' can have */
503 detail->flush_time = now;
NeilBrownc5b29f82010-08-12 16:55:22 +1000504 detail->nextcheck = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 cache_flush();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506}
Trond Myklebust24c37672008-12-23 16:30:12 -0500507EXPORT_SYMBOL_GPL(cache_purge);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
509
510/*
511 * Deferral and Revisiting of Requests.
512 *
513 * If a cache lookup finds a pending entry, we
514 * need to defer the request and revisit it later.
515 * All deferred requests are stored in a hash table,
516 * indexed by "struct cache_head *".
517 * As it may be wasteful to store a whole request
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800518 * structure, we allow the request to provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 * deferred form, which must contain a
520 * 'struct cache_deferred_req'
521 * This cache_deferred_req contains a method to allow
522 * it to be revisited when cache info is available
523 */
524
525#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
526#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
527
528#define DFR_MAX 300 /* ??? */
529
530static DEFINE_SPINLOCK(cache_defer_lock);
531static LIST_HEAD(cache_defer_list);
NeilBrown11174492010-08-12 17:04:08 +1000532static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533static int cache_defer_cnt;
534
J. Bruce Fields6610f722010-08-26 13:19:52 -0400535static void __unhash_deferred_req(struct cache_deferred_req *dreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536{
NeilBrown11174492010-08-12 17:04:08 +1000537 hlist_del_init(&dreq->hash);
NeilBrowne33534d2010-10-07 15:29:46 +1100538 if (!list_empty(&dreq->recent)) {
539 list_del_init(&dreq->recent);
540 cache_defer_cnt--;
541 }
J. Bruce Fields6610f722010-08-26 13:19:52 -0400542}
543
544static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
545{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 int hash = DFR_HASH(item);
547
NeilBrowne33534d2010-10-07 15:29:46 +1100548 INIT_LIST_HEAD(&dreq->recent);
NeilBrown11174492010-08-12 17:04:08 +1000549 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
J. Bruce Fields6610f722010-08-26 13:19:52 -0400550}
551
NeilBrowne33534d2010-10-07 15:29:46 +1100552static void setup_deferral(struct cache_deferred_req *dreq,
553 struct cache_head *item,
554 int count_me)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557 dreq->item = item;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 spin_lock(&cache_defer_lock);
560
J. Bruce Fields6610f722010-08-26 13:19:52 -0400561 __hash_deferred_req(dreq, item);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
NeilBrowne33534d2010-10-07 15:29:46 +1100563 if (count_me) {
564 cache_defer_cnt++;
565 list_add(&dreq->recent, &cache_defer_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 }
NeilBrowne33534d2010-10-07 15:29:46 +1100567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 spin_unlock(&cache_defer_lock);
569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
J. Bruce Fields3211af12010-08-26 16:56:23 -0400572struct thread_deferred_req {
573 struct cache_deferred_req handle;
574 struct completion completion;
575};
576
577static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
578{
579 struct thread_deferred_req *dr =
580 container_of(dreq, struct thread_deferred_req, handle);
581 complete(&dr->completion);
582}
583
NeilBrownd29068c2010-10-07 15:29:46 +1100584static void cache_wait_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400585{
586 struct thread_deferred_req sleeper;
587 struct cache_deferred_req *dreq = &sleeper.handle;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400588
589 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
590 dreq->revisit = cache_restart_thread;
591
NeilBrowne33534d2010-10-07 15:29:46 +1100592 setup_deferral(dreq, item, 0);
J. Bruce Fields3211af12010-08-26 16:56:23 -0400593
NeilBrownd29068c2010-10-07 15:29:46 +1100594 if (!test_bit(CACHE_PENDING, &item->flags) ||
NeilBrown277f68d2010-09-22 12:55:06 +1000595 wait_for_completion_interruptible_timeout(
J. Bruce Fields3211af12010-08-26 16:56:23 -0400596 &sleeper.completion, req->thread_wait) <= 0) {
597 /* The completion wasn't completed, so we need
598 * to clean up
599 */
600 spin_lock(&cache_defer_lock);
NeilBrown11174492010-08-12 17:04:08 +1000601 if (!hlist_unhashed(&sleeper.handle.hash)) {
J. Bruce Fields3211af12010-08-26 16:56:23 -0400602 __unhash_deferred_req(&sleeper.handle);
603 spin_unlock(&cache_defer_lock);
604 } else {
605 /* cache_revisit_request already removed
606 * this from the hash table, but hasn't
607 * called ->revisit yet. It will very soon
608 * and we need to wait for it.
609 */
610 spin_unlock(&cache_defer_lock);
611 wait_for_completion(&sleeper.completion);
612 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 }
J. Bruce Fields3211af12010-08-26 16:56:23 -0400614}
615
NeilBrowne33534d2010-10-07 15:29:46 +1100616static void cache_limit_defers(void)
617{
618 /* Make sure we haven't exceed the limit of allowed deferred
619 * requests.
620 */
621 struct cache_deferred_req *discard = NULL;
622
623 if (cache_defer_cnt <= DFR_MAX)
624 return;
625
626 spin_lock(&cache_defer_lock);
627
628 /* Consider removing either the first or the last */
629 if (cache_defer_cnt > DFR_MAX) {
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -0500630 if (prandom_u32() & 1)
NeilBrowne33534d2010-10-07 15:29:46 +1100631 discard = list_entry(cache_defer_list.next,
632 struct cache_deferred_req, recent);
633 else
634 discard = list_entry(cache_defer_list.prev,
635 struct cache_deferred_req, recent);
636 __unhash_deferred_req(discard);
637 }
638 spin_unlock(&cache_defer_lock);
639 if (discard)
640 discard->revisit(discard, 1);
641}
642
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500643/* Return true if and only if a deferred request is queued. */
644static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400645{
646 struct cache_deferred_req *dreq;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400647
J. Bruce Fields3211af12010-08-26 16:56:23 -0400648 if (req->thread_wait) {
NeilBrownd29068c2010-10-07 15:29:46 +1100649 cache_wait_req(req, item);
650 if (!test_bit(CACHE_PENDING, &item->flags))
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500651 return false;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400652 }
653 dreq = req->defer(req);
654 if (dreq == NULL)
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500655 return false;
NeilBrowne33534d2010-10-07 15:29:46 +1100656 setup_deferral(dreq, item, 1);
NeilBrownd29068c2010-10-07 15:29:46 +1100657 if (!test_bit(CACHE_PENDING, &item->flags))
658 /* Bit could have been cleared before we managed to
659 * set up the deferral, so need to revisit just in case
660 */
661 cache_revisit_request(item);
NeilBrowne33534d2010-10-07 15:29:46 +1100662
663 cache_limit_defers();
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500664 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665}
666
667static void cache_revisit_request(struct cache_head *item)
668{
669 struct cache_deferred_req *dreq;
670 struct list_head pending;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800671 struct hlist_node *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 int hash = DFR_HASH(item);
673
674 INIT_LIST_HEAD(&pending);
675 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800676
Sasha Levinb67bfe02013-02-27 17:06:00 -0800677 hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash)
NeilBrown11174492010-08-12 17:04:08 +1000678 if (dreq->item == item) {
679 __unhash_deferred_req(dreq);
680 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 }
NeilBrown11174492010-08-12 17:04:08 +1000682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 spin_unlock(&cache_defer_lock);
684
685 while (!list_empty(&pending)) {
686 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
687 list_del_init(&dreq->recent);
688 dreq->revisit(dreq, 0);
689 }
690}
691
692void cache_clean_deferred(void *owner)
693{
694 struct cache_deferred_req *dreq, *tmp;
695 struct list_head pending;
696
697
698 INIT_LIST_HEAD(&pending);
699 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
702 if (dreq->owner == owner) {
J. Bruce Fields6610f722010-08-26 13:19:52 -0400703 __unhash_deferred_req(dreq);
NeilBrowne95dffa2010-09-22 12:55:06 +1000704 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 }
706 }
707 spin_unlock(&cache_defer_lock);
708
709 while (!list_empty(&pending)) {
710 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
711 list_del_init(&dreq->recent);
712 dreq->revisit(dreq, 1);
713 }
714}
715
716/*
717 * communicate with user-space
718 *
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500719 * We have a magic /proc file - /proc/sunrpc/<cachename>/channel.
720 * On read, you get a full request, or block.
721 * On write, an update request is processed.
722 * Poll works if anything to read, and always allows write.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800724 * Implemented by linked list of requests. Each open file has
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500725 * a ->private that also exists in this list. New requests are added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 * to the end and may wakeup and preceding readers.
727 * New readers are added to the head. If, on read, an item is found with
728 * CACHE_UPCALLING clear, we free it from the list.
729 *
730 */
731
732static DEFINE_SPINLOCK(queue_lock);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800733static DEFINE_MUTEX(queue_io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
735struct cache_queue {
736 struct list_head list;
737 int reader; /* if 0, then request */
738};
739struct cache_request {
740 struct cache_queue q;
741 struct cache_head *item;
742 char * buf;
743 int len;
744 int readers;
745};
746struct cache_reader {
747 struct cache_queue q;
748 int offset; /* if non-0, we have a refcnt on next request */
749};
750
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +0300751static int cache_request(struct cache_detail *detail,
752 struct cache_request *crq)
753{
754 char *bp = crq->buf;
755 int len = PAGE_SIZE;
756
757 detail->cache_request(detail, crq->item, &bp, &len);
758 if (len < 0)
759 return -EAGAIN;
760 return PAGE_SIZE - len;
761}
762
Trond Myklebust173912a2009-08-09 15:14:29 -0400763static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
764 loff_t *ppos, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765{
766 struct cache_reader *rp = filp->private_data;
767 struct cache_request *rq;
Al Viro496ad9a2013-01-23 17:07:38 -0500768 struct inode *inode = file_inode(filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 int err;
770
771 if (count == 0)
772 return 0;
773
Al Viro59551022016-01-22 15:40:57 -0500774 inode_lock(inode); /* protect against multiple concurrent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 * readers on this file */
776 again:
777 spin_lock(&queue_lock);
778 /* need to find next request */
779 while (rp->q.list.next != &cd->queue &&
780 list_entry(rp->q.list.next, struct cache_queue, list)
781 ->reader) {
782 struct list_head *next = rp->q.list.next;
783 list_move(&rp->q.list, next);
784 }
785 if (rp->q.list.next == &cd->queue) {
786 spin_unlock(&queue_lock);
Al Viro59551022016-01-22 15:40:57 -0500787 inode_unlock(inode);
Weston Andros Adamson0db74d92012-10-23 10:43:36 -0400788 WARN_ON_ONCE(rp->offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 return 0;
790 }
791 rq = container_of(rp->q.list.next, struct cache_request, q.list);
Weston Andros Adamson0db74d92012-10-23 10:43:36 -0400792 WARN_ON_ONCE(rq->q.reader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 if (rp->offset == 0)
794 rq->readers++;
795 spin_unlock(&queue_lock);
796
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +0300797 if (rq->len == 0) {
798 err = cache_request(cd, rq);
799 if (err < 0)
800 goto out;
801 rq->len = err;
802 }
803
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
805 err = -EAGAIN;
806 spin_lock(&queue_lock);
807 list_move(&rp->q.list, &rq->q.list);
808 spin_unlock(&queue_lock);
809 } else {
810 if (rp->offset + count > rq->len)
811 count = rq->len - rp->offset;
812 err = -EFAULT;
813 if (copy_to_user(buf, rq->buf + rp->offset, count))
814 goto out;
815 rp->offset += count;
816 if (rp->offset >= rq->len) {
817 rp->offset = 0;
818 spin_lock(&queue_lock);
819 list_move(&rp->q.list, &rq->q.list);
820 spin_unlock(&queue_lock);
821 }
822 err = 0;
823 }
824 out:
825 if (rp->offset == 0) {
826 /* need to release rq */
827 spin_lock(&queue_lock);
828 rq->readers--;
829 if (rq->readers == 0 &&
830 !test_bit(CACHE_PENDING, &rq->item->flags)) {
831 list_del(&rq->q.list);
832 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800833 cache_put(rq->item, cd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 kfree(rq->buf);
835 kfree(rq);
836 } else
837 spin_unlock(&queue_lock);
838 }
839 if (err == -EAGAIN)
840 goto again;
Al Viro59551022016-01-22 15:40:57 -0500841 inode_unlock(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 return err ? err : count;
843}
844
Trond Myklebustda770052009-08-09 15:14:28 -0400845static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
846 size_t count, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847{
Trond Myklebustda770052009-08-09 15:14:28 -0400848 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849
Dan Carpenter6d8d1742012-01-18 12:56:02 +0300850 if (count == 0)
851 return -EINVAL;
Trond Myklebustda770052009-08-09 15:14:28 -0400852 if (copy_from_user(kaddr, buf, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 return -EFAULT;
Trond Myklebustda770052009-08-09 15:14:28 -0400854 kaddr[count] = '\0';
855 ret = cd->cache_parse(cd, kaddr, count);
856 if (!ret)
857 ret = count;
858 return ret;
859}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860
Trond Myklebustda770052009-08-09 15:14:28 -0400861static ssize_t cache_slow_downcall(const char __user *buf,
862 size_t count, struct cache_detail *cd)
863{
864 static char write_buf[8192]; /* protected by queue_io_mutex */
865 ssize_t ret = -EINVAL;
866
867 if (count >= sizeof(write_buf))
868 goto out;
869 mutex_lock(&queue_io_mutex);
870 ret = cache_do_downcall(write_buf, buf, count, cd);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800871 mutex_unlock(&queue_io_mutex);
Trond Myklebustda770052009-08-09 15:14:28 -0400872out:
873 return ret;
874}
875
876static ssize_t cache_downcall(struct address_space *mapping,
877 const char __user *buf,
878 size_t count, struct cache_detail *cd)
879{
880 struct page *page;
881 char *kaddr;
882 ssize_t ret = -ENOMEM;
883
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300884 if (count >= PAGE_SIZE)
Trond Myklebustda770052009-08-09 15:14:28 -0400885 goto out_slow;
886
887 page = find_or_create_page(mapping, 0, GFP_KERNEL);
888 if (!page)
889 goto out_slow;
890
891 kaddr = kmap(page);
892 ret = cache_do_downcall(kaddr, buf, count, cd);
893 kunmap(page);
894 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300895 put_page(page);
Trond Myklebustda770052009-08-09 15:14:28 -0400896 return ret;
897out_slow:
898 return cache_slow_downcall(buf, count, cd);
899}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
Trond Myklebust173912a2009-08-09 15:14:29 -0400901static ssize_t cache_write(struct file *filp, const char __user *buf,
902 size_t count, loff_t *ppos,
903 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904{
Trond Myklebustda770052009-08-09 15:14:28 -0400905 struct address_space *mapping = filp->f_mapping;
Al Viro496ad9a2013-01-23 17:07:38 -0500906 struct inode *inode = file_inode(filp);
Trond Myklebustda770052009-08-09 15:14:28 -0400907 ssize_t ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
Trond Myklebustda770052009-08-09 15:14:28 -0400909 if (!cd->cache_parse)
910 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911
Al Viro59551022016-01-22 15:40:57 -0500912 inode_lock(inode);
Trond Myklebustda770052009-08-09 15:14:28 -0400913 ret = cache_downcall(mapping, buf, count, cd);
Al Viro59551022016-01-22 15:40:57 -0500914 inode_unlock(inode);
Trond Myklebustda770052009-08-09 15:14:28 -0400915out:
916 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917}
918
919static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
920
Trond Myklebust173912a2009-08-09 15:14:29 -0400921static unsigned int cache_poll(struct file *filp, poll_table *wait,
922 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923{
924 unsigned int mask;
925 struct cache_reader *rp = filp->private_data;
926 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927
928 poll_wait(filp, &queue_wait, wait);
929
930 /* alway allow write */
Al Viro1711fd9a2015-03-07 21:08:46 +0000931 mask = POLLOUT | POLLWRNORM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932
933 if (!rp)
934 return mask;
935
936 spin_lock(&queue_lock);
937
938 for (cq= &rp->q; &cq->list != &cd->queue;
939 cq = list_entry(cq->list.next, struct cache_queue, list))
940 if (!cq->reader) {
941 mask |= POLLIN | POLLRDNORM;
942 break;
943 }
944 spin_unlock(&queue_lock);
945 return mask;
946}
947
Trond Myklebust173912a2009-08-09 15:14:29 -0400948static int cache_ioctl(struct inode *ino, struct file *filp,
949 unsigned int cmd, unsigned long arg,
950 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951{
952 int len = 0;
953 struct cache_reader *rp = filp->private_data;
954 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955
956 if (cmd != FIONREAD || !rp)
957 return -EINVAL;
958
959 spin_lock(&queue_lock);
960
961 /* only find the length remaining in current request,
962 * or the length of the next request
963 */
964 for (cq= &rp->q; &cq->list != &cd->queue;
965 cq = list_entry(cq->list.next, struct cache_queue, list))
966 if (!cq->reader) {
967 struct cache_request *cr =
968 container_of(cq, struct cache_request, q);
969 len = cr->len - rp->offset;
970 break;
971 }
972 spin_unlock(&queue_lock);
973
974 return put_user(len, (int __user *)arg);
975}
976
Trond Myklebust173912a2009-08-09 15:14:29 -0400977static int cache_open(struct inode *inode, struct file *filp,
978 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979{
980 struct cache_reader *rp = NULL;
981
Trond Myklebustf7e86ab2009-08-19 18:13:00 -0400982 if (!cd || !try_module_get(cd->owner))
983 return -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 nonseekable_open(inode, filp);
985 if (filp->f_mode & FMODE_READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
Alexey Khoroshilova7823c72013-03-23 00:36:44 +0400987 if (!rp) {
988 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 return -ENOMEM;
Alexey Khoroshilova7823c72013-03-23 00:36:44 +0400990 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 rp->offset = 0;
992 rp->q.reader = 1;
993 atomic_inc(&cd->readers);
994 spin_lock(&queue_lock);
995 list_add(&rp->q.list, &cd->queue);
996 spin_unlock(&queue_lock);
997 }
998 filp->private_data = rp;
999 return 0;
1000}
1001
Trond Myklebust173912a2009-08-09 15:14:29 -04001002static int cache_release(struct inode *inode, struct file *filp,
1003 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004{
1005 struct cache_reader *rp = filp->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006
1007 if (rp) {
1008 spin_lock(&queue_lock);
1009 if (rp->offset) {
1010 struct cache_queue *cq;
1011 for (cq= &rp->q; &cq->list != &cd->queue;
1012 cq = list_entry(cq->list.next, struct cache_queue, list))
1013 if (!cq->reader) {
1014 container_of(cq, struct cache_request, q)
1015 ->readers--;
1016 break;
1017 }
1018 rp->offset = 0;
1019 }
1020 list_del(&rp->q.list);
1021 spin_unlock(&queue_lock);
1022
1023 filp->private_data = NULL;
1024 kfree(rp);
1025
NeilBrownc5b29f82010-08-12 16:55:22 +10001026 cd->last_close = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 atomic_dec(&cd->readers);
1028 }
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001029 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 return 0;
1031}
1032
1033
1034
NeilBrownf866a812009-08-04 15:22:38 +10001035static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036{
NeilBrownf9e1aed2013-06-13 12:53:42 +10001037 struct cache_queue *cq, *tmp;
1038 struct cache_request *cr;
1039 struct list_head dequeued;
1040
1041 INIT_LIST_HEAD(&dequeued);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 spin_lock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001043 list_for_each_entry_safe(cq, tmp, &detail->queue, list)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 if (!cq->reader) {
NeilBrownf9e1aed2013-06-13 12:53:42 +10001045 cr = container_of(cq, struct cache_request, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 if (cr->item != ch)
1047 continue;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001048 if (test_bit(CACHE_PENDING, &ch->flags))
1049 /* Lost a race and it is pending again */
1050 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 if (cr->readers != 0)
NeilBrown4013ede2006-03-27 01:15:07 -08001052 continue;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001053 list_move(&cr->q.list, &dequeued);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 }
1055 spin_unlock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001056 while (!list_empty(&dequeued)) {
1057 cr = list_entry(dequeued.next, struct cache_request, q.list);
1058 list_del(&cr->q.list);
1059 cache_put(cr->item, detail);
1060 kfree(cr->buf);
1061 kfree(cr);
1062 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063}
1064
1065/*
1066 * Support routines for text-based upcalls.
1067 * Fields are separated by spaces.
1068 * Fields are either mangled to quote space tab newline slosh with slosh
1069 * or a hexified with a leading \x
1070 * Record is terminated with newline.
1071 *
1072 */
1073
1074void qword_add(char **bpp, int *lp, char *str)
1075{
1076 char *bp = *bpp;
1077 int len = *lp;
Andy Shevchenko1b2e1222014-11-28 17:50:28 +02001078 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079
1080 if (len < 0) return;
1081
Rasmus Villemoes41416f22015-04-15 16:17:28 -07001082 ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
1083 if (ret >= len) {
1084 bp += len;
Andy Shevchenko1b2e1222014-11-28 17:50:28 +02001085 len = -1;
Rasmus Villemoes41416f22015-04-15 16:17:28 -07001086 } else {
1087 bp += ret;
Andy Shevchenko1b2e1222014-11-28 17:50:28 +02001088 len -= ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 *bp++ = ' ';
1090 len--;
1091 }
1092 *bpp = bp;
1093 *lp = len;
1094}
Trond Myklebust24c37672008-12-23 16:30:12 -05001095EXPORT_SYMBOL_GPL(qword_add);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096
1097void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1098{
1099 char *bp = *bpp;
1100 int len = *lp;
1101
1102 if (len < 0) return;
1103
1104 if (len > 2) {
1105 *bp++ = '\\';
1106 *bp++ = 'x';
1107 len -= 2;
1108 while (blen && len >= 2) {
Andy Shevchenko056785e2013-12-12 15:49:21 +02001109 bp = hex_byte_pack(bp, *buf++);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 len -= 2;
1111 blen--;
1112 }
1113 }
1114 if (blen || len<1) len = -1;
1115 else {
1116 *bp++ = ' ';
1117 len--;
1118 }
1119 *bpp = bp;
1120 *lp = len;
1121}
Trond Myklebust24c37672008-12-23 16:30:12 -05001122EXPORT_SYMBOL_GPL(qword_addhex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123
1124static void warn_no_listener(struct cache_detail *detail)
1125{
1126 if (detail->last_warn != detail->last_close) {
1127 detail->last_warn = detail->last_close;
1128 if (detail->warn_no_listener)
Trond Myklebust2da8ca22009-08-09 15:14:26 -04001129 detail->warn_no_listener(detail, detail->last_close != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 }
1131}
1132
J. Bruce Fields06497522010-09-19 22:55:06 -04001133static bool cache_listeners_exist(struct cache_detail *detail)
1134{
1135 if (atomic_read(&detail->readers))
1136 return true;
1137 if (detail->last_close == 0)
1138 /* This cache was never opened */
1139 return false;
1140 if (detail->last_close < seconds_since_boot() - 30)
1141 /*
1142 * We allow for the possibility that someone might
1143 * restart a userspace daemon without restarting the
1144 * server; but after 30 seconds, we give up.
1145 */
1146 return false;
1147 return true;
1148}
1149
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150/*
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001151 * register an upcall request to user-space and queue it up for read() by the
1152 * upcall daemon.
1153 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 * Each request is at most one page long.
1155 */
Stanislav Kinsbursky21cd1252013-02-04 14:02:55 +03001156int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157{
1158
1159 char *buf;
1160 struct cache_request *crq;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001161 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +03001163 if (!detail->cache_request)
1164 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165
J. Bruce Fields06497522010-09-19 22:55:06 -04001166 if (!cache_listeners_exist(detail)) {
1167 warn_no_listener(detail);
1168 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 }
NeilBrown013920e2013-06-13 12:53:42 +10001170 if (test_bit(CACHE_CLEANED, &h->flags))
1171 /* Too late to make an upcall */
1172 return -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173
1174 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1175 if (!buf)
1176 return -EAGAIN;
1177
1178 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1179 if (!crq) {
1180 kfree(buf);
1181 return -EAGAIN;
1182 }
1183
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 crq->q.reader = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 crq->buf = buf;
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +03001186 crq->len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 crq->readers = 0;
1188 spin_lock(&queue_lock);
NeilBrowna6ab1e82016-03-04 17:20:13 +11001189 if (test_bit(CACHE_PENDING, &h->flags)) {
1190 crq->item = cache_get(h);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001191 list_add_tail(&crq->q.list, &detail->queue);
NeilBrowna6ab1e82016-03-04 17:20:13 +11001192 } else
NeilBrownf9e1aed2013-06-13 12:53:42 +10001193 /* Lost a race, no longer PENDING, so don't enqueue */
1194 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 spin_unlock(&queue_lock);
1196 wake_up(&queue_wait);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001197 if (ret == -EAGAIN) {
1198 kfree(buf);
1199 kfree(crq);
1200 }
1201 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202}
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001203EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204
1205/*
1206 * parse a message from user-space and pass it
1207 * to an appropriate cache
1208 * Messages are, like requests, separated into fields by
1209 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1210 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001211 * Message is
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 * reply cachename expiry key ... content....
1213 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001214 * key and content are both parsed by cache
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 */
1216
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217int qword_get(char **bpp, char *dest, int bufsize)
1218{
1219 /* return bytes copied, or -1 on error */
1220 char *bp = *bpp;
1221 int len = 0;
1222
1223 while (*bp == ' ') bp++;
1224
1225 if (bp[0] == '\\' && bp[1] == 'x') {
1226 /* HEX STRING */
1227 bp += 2;
Stefan Hajnoczib7052cd2016-02-18 18:55:54 +00001228 while (len < bufsize - 1) {
Andy Shevchenkoe7f483ea2010-09-21 09:40:25 +03001229 int h, l;
1230
1231 h = hex_to_bin(bp[0]);
1232 if (h < 0)
1233 break;
1234
1235 l = hex_to_bin(bp[1]);
1236 if (l < 0)
1237 break;
1238
1239 *dest++ = (h << 4) | l;
1240 bp += 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 len++;
1242 }
1243 } else {
1244 /* text with \nnn octal quoting */
1245 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1246 if (*bp == '\\' &&
1247 isodigit(bp[1]) && (bp[1] <= '3') &&
1248 isodigit(bp[2]) &&
1249 isodigit(bp[3])) {
1250 int byte = (*++bp -'0');
1251 bp++;
1252 byte = (byte << 3) | (*bp++ - '0');
1253 byte = (byte << 3) | (*bp++ - '0');
1254 *dest++ = byte;
1255 len++;
1256 } else {
1257 *dest++ = *bp++;
1258 len++;
1259 }
1260 }
1261 }
1262
1263 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1264 return -1;
1265 while (*bp == ' ') bp++;
1266 *bpp = bp;
1267 *dest = '\0';
1268 return len;
1269}
Trond Myklebust24c37672008-12-23 16:30:12 -05001270EXPORT_SYMBOL_GPL(qword_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271
1272
1273/*
1274 * support /proc/sunrpc/cache/$CACHENAME/content
1275 * as a seqfile.
1276 * We call ->cache_show passing NULL for the item to
1277 * get a header, then pass each real item in the cache
1278 */
1279
Kinglong Meec8c081b2015-07-27 11:09:42 +08001280void *cache_seq_start(struct seq_file *m, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001281 __acquires(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282{
1283 loff_t n = *pos;
Eric Dumazet95c96172012-04-15 05:58:06 +00001284 unsigned int hash, entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 struct cache_head *ch;
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001286 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287
1288 read_lock(&cd->hash_lock);
1289 if (!n--)
1290 return SEQ_START_TOKEN;
1291 hash = n >> 32;
1292 entry = n & ((1LL<<32) - 1);
1293
Kinglong Mee129e5822015-07-27 11:10:15 +08001294 hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 if (!entry--)
1296 return ch;
1297 n &= ~((1LL<<32) - 1);
1298 do {
1299 hash++;
1300 n += 1LL<<32;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001301 } while(hash < cd->hash_size &&
Kinglong Mee129e5822015-07-27 11:10:15 +08001302 hlist_empty(&cd->hash_table[hash]));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 if (hash >= cd->hash_size)
1304 return NULL;
1305 *pos = n+1;
Kinglong Mee129e5822015-07-27 11:10:15 +08001306 return hlist_entry_safe(cd->hash_table[hash].first,
1307 struct cache_head, cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308}
Kinglong Meec8c081b2015-07-27 11:09:42 +08001309EXPORT_SYMBOL_GPL(cache_seq_start);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310
Kinglong Meec8c081b2015-07-27 11:09:42 +08001311void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312{
1313 struct cache_head *ch = p;
1314 int hash = (*pos >> 32);
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001315 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316
1317 if (p == SEQ_START_TOKEN)
1318 hash = 0;
Kinglong Mee129e5822015-07-27 11:10:15 +08001319 else if (ch->cache_list.next == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 hash++;
1321 *pos += 1LL<<32;
1322 } else {
1323 ++*pos;
Kinglong Mee129e5822015-07-27 11:10:15 +08001324 return hlist_entry_safe(ch->cache_list.next,
1325 struct cache_head, cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 }
1327 *pos &= ~((1LL<<32) - 1);
1328 while (hash < cd->hash_size &&
Kinglong Mee129e5822015-07-27 11:10:15 +08001329 hlist_empty(&cd->hash_table[hash])) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 hash++;
1331 *pos += 1LL<<32;
1332 }
1333 if (hash >= cd->hash_size)
1334 return NULL;
1335 ++*pos;
Kinglong Mee129e5822015-07-27 11:10:15 +08001336 return hlist_entry_safe(cd->hash_table[hash].first,
1337 struct cache_head, cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338}
Kinglong Meec8c081b2015-07-27 11:09:42 +08001339EXPORT_SYMBOL_GPL(cache_seq_next);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340
Kinglong Meec8c081b2015-07-27 11:09:42 +08001341void cache_seq_stop(struct seq_file *m, void *p)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001342 __releases(cd->hash_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343{
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001344 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 read_unlock(&cd->hash_lock);
1346}
Kinglong Meec8c081b2015-07-27 11:09:42 +08001347EXPORT_SYMBOL_GPL(cache_seq_stop);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348
1349static int c_show(struct seq_file *m, void *p)
1350{
1351 struct cache_head *cp = p;
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001352 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353
1354 if (p == SEQ_START_TOKEN)
1355 return cd->cache_show(m, cd, NULL);
1356
1357 ifdebug(CACHE)
NeilBrown4013ede2006-03-27 01:15:07 -08001358 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
NeilBrownc5b29f82010-08-12 16:55:22 +10001359 convert_to_wallclock(cp->expiry_time),
1360 atomic_read(&cp->ref.refcount), cp->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 cache_get(cp);
1362 if (cache_check(cd, cp, NULL))
1363 /* cache_check does a cache_put on failure */
1364 seq_printf(m, "# ");
NeilBrown200724a2012-07-12 10:37:34 +10001365 else {
1366 if (cache_is_expired(cd, cp))
1367 seq_printf(m, "# ");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368 cache_put(cp, cd);
NeilBrown200724a2012-07-12 10:37:34 +10001369 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370
1371 return cd->cache_show(m, cd, cp);
1372}
1373
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001374static const struct seq_operations cache_content_op = {
Kinglong Meec8c081b2015-07-27 11:09:42 +08001375 .start = cache_seq_start,
1376 .next = cache_seq_next,
1377 .stop = cache_seq_stop,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378 .show = c_show,
1379};
1380
Trond Myklebust173912a2009-08-09 15:14:29 -04001381static int content_open(struct inode *inode, struct file *file,
1382 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383{
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001384 struct seq_file *seq;
1385 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001387 if (!cd || !try_module_get(cd->owner))
1388 return -EACCES;
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001389
1390 err = seq_open(file, &cache_content_op);
1391 if (err) {
Li Zefana5990ea2010-03-11 14:08:10 -08001392 module_put(cd->owner);
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001393 return err;
Li Zefana5990ea2010-03-11 14:08:10 -08001394 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001396 seq = file->private_data;
1397 seq->private = cd;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001398 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001401static int content_release(struct inode *inode, struct file *file,
1402 struct cache_detail *cd)
1403{
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001404 int ret = seq_release(inode, file);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001405 module_put(cd->owner);
1406 return ret;
1407}
1408
1409static int open_flush(struct inode *inode, struct file *file,
1410 struct cache_detail *cd)
1411{
1412 if (!cd || !try_module_get(cd->owner))
1413 return -EACCES;
1414 return nonseekable_open(inode, file);
1415}
1416
1417static int release_flush(struct inode *inode, struct file *file,
1418 struct cache_detail *cd)
1419{
1420 module_put(cd->owner);
1421 return 0;
1422}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423
1424static ssize_t read_flush(struct file *file, char __user *buf,
Trond Myklebust173912a2009-08-09 15:14:29 -04001425 size_t count, loff_t *ppos,
1426 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427{
Sasha Levin212ba902012-07-17 00:01:26 +02001428 char tbuf[22];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 unsigned long p = *ppos;
Chuck Lever01b29692007-10-26 13:31:20 -04001430 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431
Sasha Levin212ba902012-07-17 00:01:26 +02001432 snprintf(tbuf, sizeof(tbuf), "%lu\n", convert_to_wallclock(cd->flush_time));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433 len = strlen(tbuf);
1434 if (p >= len)
1435 return 0;
1436 len -= p;
Chuck Lever01b29692007-10-26 13:31:20 -04001437 if (len > count)
1438 len = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439 if (copy_to_user(buf, (void*)(tbuf+p), len))
Chuck Lever01b29692007-10-26 13:31:20 -04001440 return -EFAULT;
1441 *ppos += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 return len;
1443}
1444
Trond Myklebust173912a2009-08-09 15:14:29 -04001445static ssize_t write_flush(struct file *file, const char __user *buf,
1446 size_t count, loff_t *ppos,
1447 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 char tbuf[20];
NeilBrownc5b29f82010-08-12 16:55:22 +10001450 char *bp, *ep;
Neil Brown77862032015-10-16 08:59:08 +11001451 time_t then, now;
NeilBrownc5b29f82010-08-12 16:55:22 +10001452
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;
Neil Brown77862032015-10-16 08:59:08 +11001463 then = get_expiry(&bp);
1464 now = seconds_since_boot();
1465 cd->nextcheck = now;
1466 /* Can only set flush_time to 1 second beyond "now", or
1467 * possibly 1 second beyond flushtime. This is because
1468 * flush_time never goes backwards so it mustn't get too far
1469 * ahead of time.
1470 */
1471 if (then >= now) {
1472 /* Want to flush everything, so behave like cache_purge() */
1473 if (cd->flush_time >= now)
1474 now = cd->flush_time + 1;
1475 then = now;
1476 }
1477
1478 cd->flush_time = then;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 cache_flush();
1480
1481 *ppos += count;
1482 return count;
1483}
1484
Trond Myklebust173912a2009-08-09 15:14:29 -04001485static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1486 size_t count, loff_t *ppos)
1487{
Al Virod9dda782013-03-31 18:16:14 -04001488 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001489
1490 return cache_read(filp, buf, count, ppos, cd);
1491}
1492
1493static ssize_t cache_write_procfs(struct file *filp, const char __user *buf,
1494 size_t count, loff_t *ppos)
1495{
Al Virod9dda782013-03-31 18:16:14 -04001496 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001497
1498 return cache_write(filp, buf, count, ppos, cd);
1499}
1500
1501static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
1502{
Al Virod9dda782013-03-31 18:16:14 -04001503 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001504
1505 return cache_poll(filp, wait, cd);
1506}
1507
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001508static long cache_ioctl_procfs(struct file *filp,
1509 unsigned int cmd, unsigned long arg)
Trond Myklebust173912a2009-08-09 15:14:29 -04001510{
Al Viro496ad9a2013-01-23 17:07:38 -05001511 struct inode *inode = file_inode(filp);
Al Virod9dda782013-03-31 18:16:14 -04001512 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001513
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001514 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001515}
1516
1517static int cache_open_procfs(struct inode *inode, struct file *filp)
1518{
Al Virod9dda782013-03-31 18:16:14 -04001519 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001520
1521 return cache_open(inode, filp, cd);
1522}
1523
1524static int cache_release_procfs(struct inode *inode, struct file *filp)
1525{
Al Virod9dda782013-03-31 18:16:14 -04001526 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001527
1528 return cache_release(inode, filp, cd);
1529}
1530
1531static const struct file_operations cache_file_operations_procfs = {
1532 .owner = THIS_MODULE,
1533 .llseek = no_llseek,
1534 .read = cache_read_procfs,
1535 .write = cache_write_procfs,
1536 .poll = cache_poll_procfs,
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001537 .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
Trond Myklebust173912a2009-08-09 15:14:29 -04001538 .open = cache_open_procfs,
1539 .release = cache_release_procfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540};
Trond Myklebust173912a2009-08-09 15:14:29 -04001541
1542static int content_open_procfs(struct inode *inode, struct file *filp)
1543{
Al Virod9dda782013-03-31 18:16:14 -04001544 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001545
1546 return content_open(inode, filp, cd);
1547}
1548
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001549static int content_release_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 content_release(inode, filp, cd);
1554}
1555
Trond Myklebust173912a2009-08-09 15:14:29 -04001556static const struct file_operations content_file_operations_procfs = {
1557 .open = content_open_procfs,
1558 .read = seq_read,
1559 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001560 .release = content_release_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001561};
1562
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001563static int open_flush_procfs(struct inode *inode, struct file *filp)
1564{
Al Virod9dda782013-03-31 18:16:14 -04001565 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001566
1567 return open_flush(inode, filp, cd);
1568}
1569
1570static int release_flush_procfs(struct inode *inode, struct file *filp)
1571{
Al Virod9dda782013-03-31 18:16:14 -04001572 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001573
1574 return release_flush(inode, filp, cd);
1575}
1576
Trond Myklebust173912a2009-08-09 15:14:29 -04001577static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1578 size_t count, loff_t *ppos)
1579{
Al Virod9dda782013-03-31 18:16:14 -04001580 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001581
1582 return read_flush(filp, buf, count, ppos, cd);
1583}
1584
1585static ssize_t write_flush_procfs(struct file *filp,
1586 const char __user *buf,
1587 size_t count, loff_t *ppos)
1588{
Al Virod9dda782013-03-31 18:16:14 -04001589 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001590
1591 return write_flush(filp, buf, count, ppos, cd);
1592}
1593
1594static const struct file_operations cache_flush_operations_procfs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001595 .open = open_flush_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001596 .read = read_flush_procfs,
1597 .write = write_flush_procfs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001598 .release = release_flush_procfs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001599 .llseek = no_llseek,
Trond Myklebust173912a2009-08-09 15:14:29 -04001600};
1601
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001602static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001603{
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001604 struct sunrpc_net *sn;
1605
Trond Myklebust173912a2009-08-09 15:14:29 -04001606 if (cd->u.procfs.proc_ent == NULL)
1607 return;
1608 if (cd->u.procfs.flush_ent)
1609 remove_proc_entry("flush", cd->u.procfs.proc_ent);
1610 if (cd->u.procfs.channel_ent)
1611 remove_proc_entry("channel", cd->u.procfs.proc_ent);
1612 if (cd->u.procfs.content_ent)
1613 remove_proc_entry("content", cd->u.procfs.proc_ent);
1614 cd->u.procfs.proc_ent = NULL;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001615 sn = net_generic(net, sunrpc_net_id);
1616 remove_proc_entry(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001617}
1618
1619#ifdef CONFIG_PROC_FS
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001620static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001621{
1622 struct proc_dir_entry *p;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001623 struct sunrpc_net *sn;
Trond Myklebust173912a2009-08-09 15:14:29 -04001624
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001625 sn = net_generic(net, sunrpc_net_id);
1626 cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc);
Trond Myklebust173912a2009-08-09 15:14:29 -04001627 if (cd->u.procfs.proc_ent == NULL)
1628 goto out_nomem;
1629 cd->u.procfs.channel_ent = NULL;
1630 cd->u.procfs.content_ent = NULL;
1631
1632 p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR,
1633 cd->u.procfs.proc_ent,
1634 &cache_flush_operations_procfs, cd);
1635 cd->u.procfs.flush_ent = p;
1636 if (p == NULL)
1637 goto out_nomem;
1638
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +03001639 if (cd->cache_request || cd->cache_parse) {
Trond Myklebust173912a2009-08-09 15:14:29 -04001640 p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR,
1641 cd->u.procfs.proc_ent,
1642 &cache_file_operations_procfs, cd);
1643 cd->u.procfs.channel_ent = p;
1644 if (p == NULL)
1645 goto out_nomem;
1646 }
1647 if (cd->cache_show) {
Yanchuan Nianec168672013-01-04 19:45:35 +08001648 p = proc_create_data("content", S_IFREG|S_IRUSR,
Trond Myklebust173912a2009-08-09 15:14:29 -04001649 cd->u.procfs.proc_ent,
1650 &content_file_operations_procfs, cd);
1651 cd->u.procfs.content_ent = p;
1652 if (p == NULL)
1653 goto out_nomem;
1654 }
1655 return 0;
1656out_nomem:
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001657 remove_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001658 return -ENOMEM;
1659}
1660#else /* CONFIG_PROC_FS */
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001661static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001662{
1663 return 0;
1664}
1665#endif
1666
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001667void __init cache_initialize(void)
1668{
Tejun Heo203b42f2012-08-21 13:18:23 -07001669 INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001670}
1671
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001672int cache_register_net(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001673{
1674 int ret;
1675
1676 sunrpc_init_cache_detail(cd);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001677 ret = create_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001678 if (ret)
1679 sunrpc_destroy_cache_detail(cd);
1680 return ret;
1681}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001682EXPORT_SYMBOL_GPL(cache_register_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001683
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001684void cache_unregister_net(struct cache_detail *cd, struct net *net)
1685{
1686 remove_cache_proc_entries(cd, net);
1687 sunrpc_destroy_cache_detail(cd);
1688}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001689EXPORT_SYMBOL_GPL(cache_unregister_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001690
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001691struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001692{
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001693 struct cache_detail *cd;
Kinglong Mee129e5822015-07-27 11:10:15 +08001694 int i;
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001695
1696 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
1697 if (cd == NULL)
1698 return ERR_PTR(-ENOMEM);
1699
Kinglong Mee129e5822015-07-27 11:10:15 +08001700 cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head),
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001701 GFP_KERNEL);
1702 if (cd->hash_table == NULL) {
1703 kfree(cd);
1704 return ERR_PTR(-ENOMEM);
1705 }
Kinglong Mee129e5822015-07-27 11:10:15 +08001706
1707 for (i = 0; i < cd->hash_size; i++)
1708 INIT_HLIST_HEAD(&cd->hash_table[i]);
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001709 cd->net = net;
1710 return cd;
Trond Myklebust173912a2009-08-09 15:14:29 -04001711}
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001712EXPORT_SYMBOL_GPL(cache_create_net);
1713
1714void cache_destroy_net(struct cache_detail *cd, struct net *net)
1715{
1716 kfree(cd->hash_table);
1717 kfree(cd);
1718}
1719EXPORT_SYMBOL_GPL(cache_destroy_net);
Trond Myklebust8854e822009-08-09 15:14:30 -04001720
1721static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1722 size_t count, loff_t *ppos)
1723{
Al Viro496ad9a2013-01-23 17:07:38 -05001724 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001725
1726 return cache_read(filp, buf, count, ppos, cd);
1727}
1728
1729static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1730 size_t count, loff_t *ppos)
1731{
Al Viro496ad9a2013-01-23 17:07:38 -05001732 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001733
1734 return cache_write(filp, buf, count, ppos, cd);
1735}
1736
1737static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait)
1738{
Al Viro496ad9a2013-01-23 17:07:38 -05001739 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001740
1741 return cache_poll(filp, wait, cd);
1742}
1743
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001744static long cache_ioctl_pipefs(struct file *filp,
Trond Myklebust8854e822009-08-09 15:14:30 -04001745 unsigned int cmd, unsigned long arg)
1746{
Al Viro496ad9a2013-01-23 17:07:38 -05001747 struct inode *inode = file_inode(filp);
Trond Myklebust8854e822009-08-09 15:14:30 -04001748 struct cache_detail *cd = RPC_I(inode)->private;
1749
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001750 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust8854e822009-08-09 15:14:30 -04001751}
1752
1753static int cache_open_pipefs(struct inode *inode, struct file *filp)
1754{
1755 struct cache_detail *cd = RPC_I(inode)->private;
1756
1757 return cache_open(inode, filp, cd);
1758}
1759
1760static int cache_release_pipefs(struct inode *inode, struct file *filp)
1761{
1762 struct cache_detail *cd = RPC_I(inode)->private;
1763
1764 return cache_release(inode, filp, cd);
1765}
1766
1767const struct file_operations cache_file_operations_pipefs = {
1768 .owner = THIS_MODULE,
1769 .llseek = no_llseek,
1770 .read = cache_read_pipefs,
1771 .write = cache_write_pipefs,
1772 .poll = cache_poll_pipefs,
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001773 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
Trond Myklebust8854e822009-08-09 15:14:30 -04001774 .open = cache_open_pipefs,
1775 .release = cache_release_pipefs,
1776};
1777
1778static int content_open_pipefs(struct inode *inode, struct file *filp)
1779{
1780 struct cache_detail *cd = RPC_I(inode)->private;
1781
1782 return content_open(inode, filp, cd);
1783}
1784
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001785static int content_release_pipefs(struct inode *inode, struct file *filp)
1786{
1787 struct cache_detail *cd = RPC_I(inode)->private;
1788
1789 return content_release(inode, filp, cd);
1790}
1791
Trond Myklebust8854e822009-08-09 15:14:30 -04001792const struct file_operations content_file_operations_pipefs = {
1793 .open = content_open_pipefs,
1794 .read = seq_read,
1795 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001796 .release = content_release_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001797};
1798
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001799static int open_flush_pipefs(struct inode *inode, struct file *filp)
1800{
1801 struct cache_detail *cd = RPC_I(inode)->private;
1802
1803 return open_flush(inode, filp, cd);
1804}
1805
1806static int release_flush_pipefs(struct inode *inode, struct file *filp)
1807{
1808 struct cache_detail *cd = RPC_I(inode)->private;
1809
1810 return release_flush(inode, filp, cd);
1811}
1812
Trond Myklebust8854e822009-08-09 15:14:30 -04001813static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1814 size_t count, loff_t *ppos)
1815{
Al Viro496ad9a2013-01-23 17:07:38 -05001816 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001817
1818 return read_flush(filp, buf, count, ppos, cd);
1819}
1820
1821static ssize_t write_flush_pipefs(struct file *filp,
1822 const char __user *buf,
1823 size_t count, loff_t *ppos)
1824{
Al Viro496ad9a2013-01-23 17:07:38 -05001825 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001826
1827 return write_flush(filp, buf, count, ppos, cd);
1828}
1829
1830const struct file_operations cache_flush_operations_pipefs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001831 .open = open_flush_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001832 .read = read_flush_pipefs,
1833 .write = write_flush_pipefs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001834 .release = release_flush_pipefs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001835 .llseek = no_llseek,
Trond Myklebust8854e822009-08-09 15:14:30 -04001836};
1837
1838int sunrpc_cache_register_pipefs(struct dentry *parent,
Al Viro64f14262011-07-25 00:35:13 -04001839 const char *name, umode_t umode,
Trond Myklebust8854e822009-08-09 15:14:30 -04001840 struct cache_detail *cd)
1841{
Al Viroa95e6912013-07-14 16:43:54 +04001842 struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd);
1843 if (IS_ERR(dir))
1844 return PTR_ERR(dir);
1845 cd->u.pipefs.dir = dir;
1846 return 0;
Trond Myklebust8854e822009-08-09 15:14:30 -04001847}
1848EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1849
1850void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1851{
1852 rpc_remove_cache_dir(cd->u.pipefs.dir);
1853 cd->u.pipefs.dir = NULL;
Trond Myklebust8854e822009-08-09 15:14:30 -04001854}
1855EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
1856