blob: 20c93b68505e6d21481fe8affa6adfbd2ad7bf49 [file] [log] [blame]
Thomas Gleixnerddc64d02019-05-31 01:09:24 -07001// SPDX-License-Identifier: GPL-2.0-only
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
3 * net/sunrpc/cache.c
4 *
5 * Generic code for various authentication-related caches
6 * used by sunrpc clients and servers.
7 *
8 * Copyright (C) 2002 Neil Brown <[email protected]>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 */
10
11#include <linux/types.h>
12#include <linux/fs.h>
13#include <linux/file.h>
14#include <linux/slab.h>
15#include <linux/signal.h>
16#include <linux/sched.h>
17#include <linux/kmod.h>
18#include <linux/list.h>
19#include <linux/module.h>
20#include <linux/ctype.h>
Andy Shevchenko1b2e1222014-11-28 17:50:28 +020021#include <linux/string_helpers.h>
Linus Torvalds7c0f6ba2016-12-24 11:46:01 -080022#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/poll.h>
24#include <linux/seq_file.h>
25#include <linux/proc_fs.h>
26#include <linux/net.h>
27#include <linux/workqueue.h>
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080028#include <linux/mutex.h>
Trond Myklebustda770052009-08-09 15:14:28 -040029#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/ioctls.h>
31#include <linux/sunrpc/types.h>
32#include <linux/sunrpc/cache.h>
33#include <linux/sunrpc/stats.h>
Trond Myklebust8854e822009-08-09 15:14:30 -040034#include <linux/sunrpc/rpc_pipe_fs.h>
Trond Myklebust78a947f2020-03-01 18:21:44 -050035#include <trace/events/sunrpc.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
Neil Brown77862032015-10-16 08:59:08 +110043static void cache_init(struct cache_head *h, struct cache_detail *detail)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
Arnd Bergmannf5599352017-10-20 16:34:42 +020045 time64_t now = seconds_since_boot();
Kinglong Mee129e5822015-07-27 11:10:15 +080046 INIT_HLIST_NODE(&h->cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 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;
Neil Brown77862032015-10-16 08:59:08 +110050 if (now <= detail->flush_time)
51 /* ensure it isn't already expired */
52 now = detail->flush_time + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 h->last_refresh = now;
54}
55
Vasily Averin4ecd55e2018-11-28 11:45:57 +030056static void cache_fresh_unlocked(struct cache_head *head,
57 struct cache_detail *detail);
58
Trond Myklebustae741362018-10-03 12:01:22 -040059static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail,
60 struct cache_head *key,
61 int hash)
62{
63 struct hlist_head *head = &detail->hash_table[hash];
64 struct cache_head *tmp;
65
66 rcu_read_lock();
67 hlist_for_each_entry_rcu(tmp, head, cache_list) {
Trond Myklebust277f27e22020-03-01 18:21:43 -050068 if (!detail->match(tmp, key))
69 continue;
70 if (test_bit(CACHE_VALID, &tmp->flags) &&
71 cache_is_expired(detail, tmp))
72 continue;
73 tmp = cache_get_rcu(tmp);
74 rcu_read_unlock();
75 return tmp;
Trond Myklebustae741362018-10-03 12:01:22 -040076 }
77 rcu_read_unlock();
78 return NULL;
79}
80
Trond Myklebust809fe3c52020-01-06 13:40:35 -050081static void sunrpc_begin_cache_remove_entry(struct cache_head *ch,
82 struct cache_detail *cd)
83{
84 /* Must be called under cd->hash_lock */
85 hlist_del_init_rcu(&ch->cache_list);
86 set_bit(CACHE_CLEANED, &ch->flags);
87 cd->entries --;
88}
89
90static void sunrpc_end_cache_remove_entry(struct cache_head *ch,
91 struct cache_detail *cd)
92{
93 cache_fresh_unlocked(ch, cd);
94 cache_put(ch, cd);
95}
96
Trond Myklebustb92a8fa2018-10-01 10:41:45 -040097static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
98 struct cache_head *key,
99 int hash)
100{
101 struct cache_head *new, *tmp, *freeme = NULL;
102 struct hlist_head *head = &detail->hash_table[hash];
NeilBrown15a5f6b2006-03-27 01:15:02 -0800103
104 new = detail->alloc();
105 if (!new)
106 return NULL;
Neil Brown2f349312006-08-05 12:14:29 -0700107 /* must fully initialise 'new', else
108 * we might get lose if we need to
109 * cache_put it soon.
110 */
Neil Brown77862032015-10-16 08:59:08 +1100111 cache_init(new, detail);
Neil Brown2f349312006-08-05 12:14:29 -0700112 detail->init(new, key);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800113
Trond Myklebust1863d772018-10-01 10:41:52 -0400114 spin_lock(&detail->hash_lock);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800115
116 /* check if entry appeared while we slept */
Amol Grover51cae672020-02-19 15:05:05 +0530117 hlist_for_each_entry_rcu(tmp, head, cache_list,
118 lockdep_is_held(&detail->hash_lock)) {
Trond Myklebust277f27e22020-03-01 18:21:43 -0500119 if (!detail->match(tmp, key))
120 continue;
121 if (test_bit(CACHE_VALID, &tmp->flags) &&
122 cache_is_expired(detail, tmp)) {
123 sunrpc_begin_cache_remove_entry(tmp, detail);
Trond Myklebust78a947f2020-03-01 18:21:44 -0500124 trace_cache_entry_expired(detail, tmp);
Trond Myklebust277f27e22020-03-01 18:21:43 -0500125 freeme = tmp;
126 break;
NeilBrown15a5f6b2006-03-27 01:15:02 -0800127 }
Trond Myklebust277f27e22020-03-01 18:21:43 -0500128 cache_get(tmp);
129 spin_unlock(&detail->hash_lock);
130 cache_put(new, detail);
131 return tmp;
NeilBrown15a5f6b2006-03-27 01:15:02 -0800132 }
Kinglong Mee129e5822015-07-27 11:10:15 +0800133
Trond Myklebustae741362018-10-03 12:01:22 -0400134 hlist_add_head_rcu(&new->cache_list, head);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800135 detail->entries++;
136 cache_get(new);
Trond Myklebust1863d772018-10-01 10:41:52 -0400137 spin_unlock(&detail->hash_lock);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800138
Trond Myklebust809fe3c52020-01-06 13:40:35 -0500139 if (freeme)
140 sunrpc_end_cache_remove_entry(freeme, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800141 return new;
142}
NeilBrown15a5f6b2006-03-27 01:15:02 -0800143
Trond Myklebustae741362018-10-03 12:01:22 -0400144struct cache_head *sunrpc_cache_lookup_rcu(struct cache_detail *detail,
145 struct cache_head *key, int hash)
146{
147 struct cache_head *ret;
148
149 ret = sunrpc_cache_find_rcu(detail, key, hash);
150 if (ret)
151 return ret;
152 /* Didn't find anything, insert an empty entry */
153 return sunrpc_cache_add_entry(detail, key, hash);
154}
155EXPORT_SYMBOL_GPL(sunrpc_cache_lookup_rcu);
156
NeilBrownf866a812009-08-04 15:22:38 +1000157static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
NeilBrownebd0cb12006-03-27 01:15:08 -0800158
Arnd Bergmannf5599352017-10-20 16:34:42 +0200159static void cache_fresh_locked(struct cache_head *head, time64_t expiry,
Neil Brown77862032015-10-16 08:59:08 +1100160 struct cache_detail *detail)
NeilBrownebd0cb12006-03-27 01:15:08 -0800161{
Arnd Bergmannf5599352017-10-20 16:34:42 +0200162 time64_t now = seconds_since_boot();
Neil Brown77862032015-10-16 08:59:08 +1100163 if (now <= detail->flush_time)
164 /* ensure it isn't immediately treated as expired */
165 now = detail->flush_time + 1;
NeilBrownebd0cb12006-03-27 01:15:08 -0800166 head->expiry_time = expiry;
Neil Brown77862032015-10-16 08:59:08 +1100167 head->last_refresh = now;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500168 smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
NeilBrown908329f2009-09-09 16:32:54 +1000169 set_bit(CACHE_VALID, &head->flags);
NeilBrownebd0cb12006-03-27 01:15:08 -0800170}
171
172static void cache_fresh_unlocked(struct cache_head *head,
NeilBrown908329f2009-09-09 16:32:54 +1000173 struct cache_detail *detail)
NeilBrownebd0cb12006-03-27 01:15:08 -0800174{
NeilBrownebd0cb12006-03-27 01:15:08 -0800175 if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
176 cache_revisit_request(head);
NeilBrownf866a812009-08-04 15:22:38 +1000177 cache_dequeue(detail, head);
NeilBrownebd0cb12006-03-27 01:15:08 -0800178 }
179}
180
Trond Myklebust78a947f2020-03-01 18:21:44 -0500181static void cache_make_negative(struct cache_detail *detail,
182 struct cache_head *h)
183{
184 set_bit(CACHE_NEGATIVE, &h->flags);
185 trace_cache_entry_make_negative(detail, h);
186}
187
188static void cache_entry_update(struct cache_detail *detail,
189 struct cache_head *h,
190 struct cache_head *new)
191{
192 if (!test_bit(CACHE_NEGATIVE, &new->flags)) {
193 detail->update(h, new);
194 trace_cache_entry_update(detail, h);
195 } else {
196 cache_make_negative(detail, h);
197 }
198}
199
NeilBrown15a5f6b2006-03-27 01:15:02 -0800200struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
201 struct cache_head *new, struct cache_head *old, int hash)
202{
203 /* The 'old' entry is to be replaced by 'new'.
204 * If 'old' is not VALID, we update it directly,
205 * otherwise we need to replace it
206 */
NeilBrown15a5f6b2006-03-27 01:15:02 -0800207 struct cache_head *tmp;
208
209 if (!test_bit(CACHE_VALID, &old->flags)) {
Trond Myklebust1863d772018-10-01 10:41:52 -0400210 spin_lock(&detail->hash_lock);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800211 if (!test_bit(CACHE_VALID, &old->flags)) {
Trond Myklebust78a947f2020-03-01 18:21:44 -0500212 cache_entry_update(detail, old, new);
Neil Brown77862032015-10-16 08:59:08 +1100213 cache_fresh_locked(old, new->expiry_time, detail);
Trond Myklebust1863d772018-10-01 10:41:52 -0400214 spin_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000215 cache_fresh_unlocked(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800216 return old;
217 }
Trond Myklebust1863d772018-10-01 10:41:52 -0400218 spin_unlock(&detail->hash_lock);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800219 }
220 /* We need to insert a new entry */
221 tmp = detail->alloc();
222 if (!tmp) {
NeilBrownbaab9352006-03-27 01:15:09 -0800223 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800224 return NULL;
225 }
Neil Brown77862032015-10-16 08:59:08 +1100226 cache_init(tmp, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800227 detail->init(tmp, old);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800228
Trond Myklebust1863d772018-10-01 10:41:52 -0400229 spin_lock(&detail->hash_lock);
Trond Myklebust78a947f2020-03-01 18:21:44 -0500230 cache_entry_update(detail, tmp, new);
Kinglong Mee129e5822015-07-27 11:10:15 +0800231 hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
NeilBrownf2d39582006-05-22 22:35:25 -0700232 detail->entries++;
NeilBrown15a5f6b2006-03-27 01:15:02 -0800233 cache_get(tmp);
Neil Brown77862032015-10-16 08:59:08 +1100234 cache_fresh_locked(tmp, new->expiry_time, detail);
235 cache_fresh_locked(old, 0, detail);
Trond Myklebust1863d772018-10-01 10:41:52 -0400236 spin_unlock(&detail->hash_lock);
NeilBrown908329f2009-09-09 16:32:54 +1000237 cache_fresh_unlocked(tmp, detail);
238 cache_fresh_unlocked(old, detail);
NeilBrownbaab9352006-03-27 01:15:09 -0800239 cache_put(old, detail);
NeilBrown15a5f6b2006-03-27 01:15:02 -0800240 return tmp;
241}
Trond Myklebust24c37672008-12-23 16:30:12 -0500242EXPORT_SYMBOL_GPL(sunrpc_cache_update);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
chaoting fanb6040f972013-03-28 22:19:45 +0800244static inline int cache_is_valid(struct cache_head *h)
NeilBrown989a19b2009-08-04 15:22:38 +1000245{
NeilBrownd202cce2010-02-03 17:31:31 +1100246 if (!test_bit(CACHE_VALID, &h->flags))
NeilBrown989a19b2009-08-04 15:22:38 +1000247 return -EAGAIN;
248 else {
249 /* entry is valid */
250 if (test_bit(CACHE_NEGATIVE, &h->flags))
251 return -ENOENT;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500252 else {
253 /*
254 * In combination with write barrier in
255 * sunrpc_cache_update, ensures that anyone
256 * using the cache entry after this sees the
257 * updated contents:
258 */
259 smp_rmb();
NeilBrown989a19b2009-08-04 15:22:38 +1000260 return 0;
J. Bruce Fieldsfdef7aa2011-01-04 14:12:47 -0500261 }
NeilBrown989a19b2009-08-04 15:22:38 +1000262 }
263}
J. Bruce Fieldse9dc1222009-08-21 11:27:29 -0400264
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500265static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h)
266{
267 int rv;
268
Trond Myklebust1863d772018-10-01 10:41:52 -0400269 spin_lock(&detail->hash_lock);
chaoting fanb6040f972013-03-28 22:19:45 +0800270 rv = cache_is_valid(h);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000271 if (rv == -EAGAIN) {
Trond Myklebust78a947f2020-03-01 18:21:44 -0500272 cache_make_negative(detail, h);
Neil Brown77862032015-10-16 08:59:08 +1100273 cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
274 detail);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000275 rv = -ENOENT;
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500276 }
Trond Myklebust1863d772018-10-01 10:41:52 -0400277 spin_unlock(&detail->hash_lock);
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500278 cache_fresh_unlocked(h, detail);
NeilBrown2a1c7f52013-06-13 12:53:42 +1000279 return rv;
J. Bruce Fields6bab93f2011-01-03 15:10:27 -0500280}
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282/*
283 * This is the generic cache management routine for all
284 * the authentication caches.
285 * It checks the currency of a cache item and will (later)
286 * initiate an upcall to fill it if needed.
287 *
288 *
289 * Returns 0 if the cache_head can be used, or cache_puts it and returns
NeilBrown989a19b2009-08-04 15:22:38 +1000290 * -EAGAIN if upcall is pending and request has been queued
291 * -ETIMEDOUT if upcall failed or request could not be queue or
292 * upcall completed but item is still invalid (implying that
293 * the cache item has been replaced with a newer one).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 * -ENOENT if cache entry was negative
295 */
296int cache_check(struct cache_detail *detail,
297 struct cache_head *h, struct cache_req *rqstp)
298{
299 int rv;
Arnd Bergmannf5599352017-10-20 16:34:42 +0200300 time64_t refresh_age, age;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
302 /* First decide return status as best we can */
chaoting fanb6040f972013-03-28 22:19:45 +0800303 rv = cache_is_valid(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
305 /* now see if we want to start an upcall */
306 refresh_age = (h->expiry_time - h->last_refresh);
NeilBrownc5b29f82010-08-12 16:55:22 +1000307 age = seconds_since_boot() - h->last_refresh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308
309 if (rqstp == NULL) {
310 if (rv == -EAGAIN)
311 rv = -ENOENT;
NeilBrown0bebc632013-06-13 12:53:42 +1000312 } else if (rv == -EAGAIN ||
313 (h->expiry_time != 0 && age > refresh_age/2)) {
Arnd Bergmannf5599352017-10-20 16:34:42 +0200314 dprintk("RPC: Want update, refage=%lld, age=%lld\n",
Chuck Lever46121cf2007-01-31 12:14:08 -0500315 refresh_age, age);
Trond Myklebust65286b82020-03-01 18:21:42 -0500316 switch (detail->cache_upcall(detail, h)) {
317 case -EINVAL:
NeilBrown9d693382019-03-22 13:16:56 +1100318 rv = try_to_negate_entry(detail, h);
Trond Myklebust65286b82020-03-01 18:21:42 -0500319 break;
320 case -EAGAIN:
321 cache_fresh_unlocked(h, detail);
322 break;
323 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 }
325
NeilBrown989a19b2009-08-04 15:22:38 +1000326 if (rv == -EAGAIN) {
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500327 if (!cache_defer_req(rqstp, h)) {
328 /*
329 * Request was not deferred; handle it as best
330 * we can ourselves:
331 */
chaoting fanb6040f972013-03-28 22:19:45 +0800332 rv = cache_is_valid(h);
NeilBrown989a19b2009-08-04 15:22:38 +1000333 if (rv == -EAGAIN)
334 rv = -ETIMEDOUT;
335 }
336 }
NeilBrown4013ede2006-03-27 01:15:07 -0800337 if (rv)
NeilBrownbaab9352006-03-27 01:15:09 -0800338 cache_put(h, detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 return rv;
340}
Trond Myklebust24c37672008-12-23 16:30:12 -0500341EXPORT_SYMBOL_GPL(cache_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343/*
344 * caches need to be periodically cleaned.
345 * For this we maintain a list of cache_detail and
346 * a current pointer into that list and into the table
347 * for that entry.
348 *
NeilBrown013920e2013-06-13 12:53:42 +1000349 * Each time cache_clean is called it finds the next non-empty entry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 * in the current table and walks the list in that entry
351 * looking for entries that can be removed.
352 *
353 * An entry gets removed if:
354 * - The expiry is before current time
355 * - The last_refresh time is before the flush_time for that cache
356 *
357 * later we might drop old entries with non-NEVER expiry if that table
358 * is getting 'full' for some definition of 'full'
359 *
360 * The question of "how often to scan a table" is an interesting one
361 * and is answered in part by the use of the "nextcheck" field in the
362 * cache_detail.
363 * When a scan of a table begins, the nextcheck field is set to a time
364 * that is well into the future.
365 * While scanning, if an expiry time is found that is earlier than the
366 * current nextcheck time, nextcheck is set to that expiry time.
367 * If the flush_time is ever set to a time earlier than the nextcheck
368 * time, the nextcheck time is then set to that flush_time.
369 *
370 * A table is then only scanned if the current time is at least
371 * the nextcheck time.
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800372 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 */
374
375static LIST_HEAD(cache_list);
376static DEFINE_SPINLOCK(cache_list_lock);
377static struct cache_detail *current_detail;
378static int current_index;
379
David Howells65f27f32006-11-22 14:55:48 +0000380static void do_cache_clean(struct work_struct *work);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +0300381static struct delayed_work cache_cleaner;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300383void sunrpc_init_cache_detail(struct cache_detail *cd)
J. Bruce Fieldsffe93862007-11-12 17:04:29 -0500384{
Trond Myklebust1863d772018-10-01 10:41:52 -0400385 spin_lock_init(&cd->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 INIT_LIST_HEAD(&cd->queue);
387 spin_lock(&cache_list_lock);
388 cd->nextcheck = 0;
389 cd->entries = 0;
Dave Wysochanski64a38e82019-07-26 18:33:01 -0400390 atomic_set(&cd->writers, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 cd->last_close = 0;
392 cd->last_warn = -1;
393 list_add(&cd->others, &cache_list);
394 spin_unlock(&cache_list_lock);
395
396 /* start the cleaning process */
Ke Wang77b00bc2016-09-01 15:30:26 +0800397 queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300399EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300401void sunrpc_destroy_cache_detail(struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402{
403 cache_purge(cd);
404 spin_lock(&cache_list_lock);
Trond Myklebust1863d772018-10-01 10:41:52 -0400405 spin_lock(&cd->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 if (current_detail == cd)
407 current_detail = NULL;
408 list_del_init(&cd->others);
Trond Myklebust1863d772018-10-01 10:41:52 -0400409 spin_unlock(&cd->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 spin_unlock(&cache_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 if (list_empty(&cache_list)) {
412 /* module must be being unloaded so its safe to kill the worker */
Trond Myklebust4011cd92007-08-07 15:33:01 -0400413 cancel_delayed_work_sync(&cache_cleaner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415}
Stanislav Kinsbursky820f9442011-11-25 17:12:40 +0300416EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418/* clean cache tries to find something to clean
419 * and cleans it.
420 * It returns 1 if it cleaned something,
421 * 0 if it didn't find anything this time
422 * -1 if it fell off the end of the list.
423 */
424static int cache_clean(void)
425{
426 int rv = 0;
427 struct list_head *next;
428
429 spin_lock(&cache_list_lock);
430
431 /* find a suitable table if we don't already have one */
432 while (current_detail == NULL ||
433 current_index >= current_detail->hash_size) {
434 if (current_detail)
435 next = current_detail->others.next;
436 else
437 next = cache_list.next;
438 if (next == &cache_list) {
439 current_detail = NULL;
440 spin_unlock(&cache_list_lock);
441 return -1;
442 }
443 current_detail = list_entry(next, struct cache_detail, others);
NeilBrownc5b29f82010-08-12 16:55:22 +1000444 if (current_detail->nextcheck > seconds_since_boot())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 current_index = current_detail->hash_size;
446 else {
447 current_index = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +1000448 current_detail->nextcheck = seconds_since_boot()+30*60;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 }
450 }
451
452 /* find a non-empty bucket in the table */
453 while (current_detail &&
454 current_index < current_detail->hash_size &&
Kinglong Mee129e5822015-07-27 11:10:15 +0800455 hlist_empty(&current_detail->hash_table[current_index]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 current_index++;
457
458 /* find a cleanable entry in the bucket and clean it, or set to next bucket */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800459
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 if (current_detail && current_index < current_detail->hash_size) {
Kinglong Mee129e5822015-07-27 11:10:15 +0800461 struct cache_head *ch = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 struct cache_detail *d;
Kinglong Mee129e5822015-07-27 11:10:15 +0800463 struct hlist_head *head;
464 struct hlist_node *tmp;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800465
Trond Myklebust1863d772018-10-01 10:41:52 -0400466 spin_lock(&current_detail->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
468 /* Ok, now to clean this strand */
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800469
Kinglong Mee129e5822015-07-27 11:10:15 +0800470 head = &current_detail->hash_table[current_index];
471 hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 if (current_detail->nextcheck > ch->expiry_time)
473 current_detail->nextcheck = ch->expiry_time+1;
NeilBrown2f50d8b2010-02-03 17:31:31 +1100474 if (!cache_is_expired(current_detail, ch))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
Trond Myklebust809fe3c52020-01-06 13:40:35 -0500477 sunrpc_begin_cache_remove_entry(ch, current_detail);
Trond Myklebust78a947f2020-03-01 18:21:44 -0500478 trace_cache_entry_expired(current_detail, ch);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 rv = 1;
NeilBrown3af49742010-02-03 17:31:31 +1100480 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
NeilBrown3af49742010-02-03 17:31:31 +1100482
Trond Myklebust1863d772018-10-01 10:41:52 -0400483 spin_unlock(&current_detail->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 d = current_detail;
485 if (!ch)
486 current_index ++;
487 spin_unlock(&cache_list_lock);
Trond Myklebust809fe3c52020-01-06 13:40:35 -0500488 if (ch)
489 sunrpc_end_cache_remove_entry(ch, d);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 } else
491 spin_unlock(&cache_list_lock);
492
493 return rv;
494}
495
496/*
497 * We want to regularly clean the cache, so we need to schedule some work ...
498 */
David Howells65f27f32006-11-22 14:55:48 +0000499static void do_cache_clean(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500{
J. Bruce Fields0aa99c42020-09-21 09:45:35 -0400501 int delay;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502
503 if (list_empty(&cache_list))
J. Bruce Fields0aa99c42020-09-21 09:45:35 -0400504 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
J. Bruce Fields0aa99c42020-09-21 09:45:35 -0400506 if (cache_clean() == -1)
507 delay = round_jiffies_relative(30*HZ);
508 else
509 delay = 5;
510
511 queue_delayed_work(system_power_efficient_wq, &cache_cleaner, delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512}
513
514
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800515/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 * Clean all caches promptly. This just calls cache_clean
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800517 * repeatedly until we are sure that every cache has had a chance to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 * be fully cleaned
519 */
520void cache_flush(void)
521{
522 while (cache_clean() != -1)
523 cond_resched();
524 while (cache_clean() != -1)
525 cond_resched();
526}
Trond Myklebust24c37672008-12-23 16:30:12 -0500527EXPORT_SYMBOL_GPL(cache_flush);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
529void cache_purge(struct cache_detail *detail)
530{
Kinglong Mee471a9302017-02-08 09:54:33 +0800531 struct cache_head *ch = NULL;
532 struct hlist_head *head = NULL;
Kinglong Mee471a9302017-02-08 09:54:33 +0800533 int i = 0;
534
Trond Myklebust1863d772018-10-01 10:41:52 -0400535 spin_lock(&detail->hash_lock);
Kinglong Mee471a9302017-02-08 09:54:33 +0800536 if (!detail->entries) {
Trond Myklebust1863d772018-10-01 10:41:52 -0400537 spin_unlock(&detail->hash_lock);
Kinglong Mee471a9302017-02-08 09:54:33 +0800538 return;
539 }
540
541 dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name);
542 for (i = 0; i < detail->hash_size; i++) {
543 head = &detail->hash_table[i];
Yihao Wu43e33922020-04-06 01:57:22 +0800544 while (!hlist_empty(head)) {
545 ch = hlist_entry(head->first, struct cache_head,
546 cache_list);
Trond Myklebust809fe3c52020-01-06 13:40:35 -0500547 sunrpc_begin_cache_remove_entry(ch, detail);
Trond Myklebust1863d772018-10-01 10:41:52 -0400548 spin_unlock(&detail->hash_lock);
Trond Myklebust809fe3c52020-01-06 13:40:35 -0500549 sunrpc_end_cache_remove_entry(ch, detail);
Trond Myklebust1863d772018-10-01 10:41:52 -0400550 spin_lock(&detail->hash_lock);
Kinglong Mee471a9302017-02-08 09:54:33 +0800551 }
552 }
Trond Myklebust1863d772018-10-01 10:41:52 -0400553 spin_unlock(&detail->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554}
Trond Myklebust24c37672008-12-23 16:30:12 -0500555EXPORT_SYMBOL_GPL(cache_purge);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557
558/*
559 * Deferral and Revisiting of Requests.
560 *
561 * If a cache lookup finds a pending entry, we
562 * need to defer the request and revisit it later.
563 * All deferred requests are stored in a hash table,
564 * indexed by "struct cache_head *".
565 * As it may be wasteful to store a whole request
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800566 * structure, we allow the request to provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 * deferred form, which must contain a
568 * 'struct cache_deferred_req'
569 * This cache_deferred_req contains a method to allow
570 * it to be revisited when cache info is available
571 */
572
573#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
574#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
575
576#define DFR_MAX 300 /* ??? */
577
578static DEFINE_SPINLOCK(cache_defer_lock);
579static LIST_HEAD(cache_defer_list);
NeilBrown11174492010-08-12 17:04:08 +1000580static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581static int cache_defer_cnt;
582
J. Bruce Fields6610f722010-08-26 13:19:52 -0400583static void __unhash_deferred_req(struct cache_deferred_req *dreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584{
NeilBrown11174492010-08-12 17:04:08 +1000585 hlist_del_init(&dreq->hash);
NeilBrowne33534d2010-10-07 15:29:46 +1100586 if (!list_empty(&dreq->recent)) {
587 list_del_init(&dreq->recent);
588 cache_defer_cnt--;
589 }
J. Bruce Fields6610f722010-08-26 13:19:52 -0400590}
591
592static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
593{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 int hash = DFR_HASH(item);
595
NeilBrowne33534d2010-10-07 15:29:46 +1100596 INIT_LIST_HEAD(&dreq->recent);
NeilBrown11174492010-08-12 17:04:08 +1000597 hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
J. Bruce Fields6610f722010-08-26 13:19:52 -0400598}
599
NeilBrowne33534d2010-10-07 15:29:46 +1100600static void setup_deferral(struct cache_deferred_req *dreq,
601 struct cache_head *item,
602 int count_me)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
605 dreq->item = item;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
607 spin_lock(&cache_defer_lock);
608
J. Bruce Fields6610f722010-08-26 13:19:52 -0400609 __hash_deferred_req(dreq, item);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
NeilBrowne33534d2010-10-07 15:29:46 +1100611 if (count_me) {
612 cache_defer_cnt++;
613 list_add(&dreq->recent, &cache_defer_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 }
NeilBrowne33534d2010-10-07 15:29:46 +1100615
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 spin_unlock(&cache_defer_lock);
617
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
J. Bruce Fields3211af12010-08-26 16:56:23 -0400620struct thread_deferred_req {
621 struct cache_deferred_req handle;
622 struct completion completion;
623};
624
625static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many)
626{
627 struct thread_deferred_req *dr =
628 container_of(dreq, struct thread_deferred_req, handle);
629 complete(&dr->completion);
630}
631
NeilBrownd29068c2010-10-07 15:29:46 +1100632static void cache_wait_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400633{
634 struct thread_deferred_req sleeper;
635 struct cache_deferred_req *dreq = &sleeper.handle;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400636
637 sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion);
638 dreq->revisit = cache_restart_thread;
639
NeilBrowne33534d2010-10-07 15:29:46 +1100640 setup_deferral(dreq, item, 0);
J. Bruce Fields3211af12010-08-26 16:56:23 -0400641
NeilBrownd29068c2010-10-07 15:29:46 +1100642 if (!test_bit(CACHE_PENDING, &item->flags) ||
NeilBrown277f68d2010-09-22 12:55:06 +1000643 wait_for_completion_interruptible_timeout(
J. Bruce Fields3211af12010-08-26 16:56:23 -0400644 &sleeper.completion, req->thread_wait) <= 0) {
645 /* The completion wasn't completed, so we need
646 * to clean up
647 */
648 spin_lock(&cache_defer_lock);
NeilBrown11174492010-08-12 17:04:08 +1000649 if (!hlist_unhashed(&sleeper.handle.hash)) {
J. Bruce Fields3211af12010-08-26 16:56:23 -0400650 __unhash_deferred_req(&sleeper.handle);
651 spin_unlock(&cache_defer_lock);
652 } else {
653 /* cache_revisit_request already removed
654 * this from the hash table, but hasn't
655 * called ->revisit yet. It will very soon
656 * and we need to wait for it.
657 */
658 spin_unlock(&cache_defer_lock);
659 wait_for_completion(&sleeper.completion);
660 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 }
J. Bruce Fields3211af12010-08-26 16:56:23 -0400662}
663
NeilBrowne33534d2010-10-07 15:29:46 +1100664static void cache_limit_defers(void)
665{
666 /* Make sure we haven't exceed the limit of allowed deferred
667 * requests.
668 */
669 struct cache_deferred_req *discard = NULL;
670
671 if (cache_defer_cnt <= DFR_MAX)
672 return;
673
674 spin_lock(&cache_defer_lock);
675
676 /* Consider removing either the first or the last */
677 if (cache_defer_cnt > DFR_MAX) {
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -0500678 if (prandom_u32() & 1)
NeilBrowne33534d2010-10-07 15:29:46 +1100679 discard = list_entry(cache_defer_list.next,
680 struct cache_deferred_req, recent);
681 else
682 discard = list_entry(cache_defer_list.prev,
683 struct cache_deferred_req, recent);
684 __unhash_deferred_req(discard);
685 }
686 spin_unlock(&cache_defer_lock);
687 if (discard)
688 discard->revisit(discard, 1);
689}
690
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500691/* Return true if and only if a deferred request is queued. */
692static bool cache_defer_req(struct cache_req *req, struct cache_head *item)
J. Bruce Fields3211af12010-08-26 16:56:23 -0400693{
694 struct cache_deferred_req *dreq;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400695
J. Bruce Fields3211af12010-08-26 16:56:23 -0400696 if (req->thread_wait) {
NeilBrownd29068c2010-10-07 15:29:46 +1100697 cache_wait_req(req, item);
698 if (!test_bit(CACHE_PENDING, &item->flags))
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500699 return false;
J. Bruce Fields3211af12010-08-26 16:56:23 -0400700 }
701 dreq = req->defer(req);
702 if (dreq == NULL)
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500703 return false;
NeilBrowne33534d2010-10-07 15:29:46 +1100704 setup_deferral(dreq, item, 1);
NeilBrownd29068c2010-10-07 15:29:46 +1100705 if (!test_bit(CACHE_PENDING, &item->flags))
706 /* Bit could have been cleared before we managed to
707 * set up the deferral, so need to revisit just in case
708 */
709 cache_revisit_request(item);
NeilBrowne33534d2010-10-07 15:29:46 +1100710
711 cache_limit_defers();
J. Bruce Fieldsd76d1812011-01-02 21:28:34 -0500712 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713}
714
715static void cache_revisit_request(struct cache_head *item)
716{
717 struct cache_deferred_req *dreq;
718 struct list_head pending;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800719 struct hlist_node *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 int hash = DFR_HASH(item);
721
722 INIT_LIST_HEAD(&pending);
723 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800724
Sasha Levinb67bfe02013-02-27 17:06:00 -0800725 hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash)
NeilBrown11174492010-08-12 17:04:08 +1000726 if (dreq->item == item) {
727 __unhash_deferred_req(dreq);
728 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 }
NeilBrown11174492010-08-12 17:04:08 +1000730
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 spin_unlock(&cache_defer_lock);
732
733 while (!list_empty(&pending)) {
734 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
735 list_del_init(&dreq->recent);
736 dreq->revisit(dreq, 0);
737 }
738}
739
740void cache_clean_deferred(void *owner)
741{
742 struct cache_deferred_req *dreq, *tmp;
743 struct list_head pending;
744
745
746 INIT_LIST_HEAD(&pending);
747 spin_lock(&cache_defer_lock);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) {
750 if (dreq->owner == owner) {
J. Bruce Fields6610f722010-08-26 13:19:52 -0400751 __unhash_deferred_req(dreq);
NeilBrowne95dffa2010-09-22 12:55:06 +1000752 list_add(&dreq->recent, &pending);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 }
754 }
755 spin_unlock(&cache_defer_lock);
756
757 while (!list_empty(&pending)) {
758 dreq = list_entry(pending.next, struct cache_deferred_req, recent);
759 list_del_init(&dreq->recent);
760 dreq->revisit(dreq, 1);
761 }
762}
763
764/*
765 * communicate with user-space
766 *
Kinglong Mee6489a8f2017-02-07 21:49:17 +0800767 * We have a magic /proc file - /proc/net/rpc/<cachename>/channel.
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500768 * On read, you get a full request, or block.
769 * On write, an update request is processed.
770 * Poll works if anything to read, and always allows write.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800772 * Implemented by linked list of requests. Each open file has
J. Bruce Fieldsa490c682007-11-06 14:15:19 -0500773 * a ->private that also exists in this list. New requests are added
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 * to the end and may wakeup and preceding readers.
775 * New readers are added to the head. If, on read, an item is found with
776 * CACHE_UPCALLING clear, we free it from the list.
777 *
778 */
779
780static DEFINE_SPINLOCK(queue_lock);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800781static DEFINE_MUTEX(queue_io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
783struct cache_queue {
784 struct list_head list;
785 int reader; /* if 0, then request */
786};
787struct cache_request {
788 struct cache_queue q;
789 struct cache_head *item;
790 char * buf;
791 int len;
792 int readers;
793};
794struct cache_reader {
795 struct cache_queue q;
796 int offset; /* if non-0, we have a refcnt on next request */
797};
798
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +0300799static int cache_request(struct cache_detail *detail,
800 struct cache_request *crq)
801{
802 char *bp = crq->buf;
803 int len = PAGE_SIZE;
804
805 detail->cache_request(detail, crq->item, &bp, &len);
806 if (len < 0)
807 return -EAGAIN;
808 return PAGE_SIZE - len;
809}
810
Trond Myklebust173912a2009-08-09 15:14:29 -0400811static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
812 loff_t *ppos, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813{
814 struct cache_reader *rp = filp->private_data;
815 struct cache_request *rq;
Al Viro496ad9a2013-01-23 17:07:38 -0500816 struct inode *inode = file_inode(filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 int err;
818
819 if (count == 0)
820 return 0;
821
Al Viro59551022016-01-22 15:40:57 -0500822 inode_lock(inode); /* protect against multiple concurrent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 * readers on this file */
824 again:
825 spin_lock(&queue_lock);
826 /* need to find next request */
827 while (rp->q.list.next != &cd->queue &&
828 list_entry(rp->q.list.next, struct cache_queue, list)
829 ->reader) {
830 struct list_head *next = rp->q.list.next;
831 list_move(&rp->q.list, next);
832 }
833 if (rp->q.list.next == &cd->queue) {
834 spin_unlock(&queue_lock);
Al Viro59551022016-01-22 15:40:57 -0500835 inode_unlock(inode);
Weston Andros Adamson0db74d92012-10-23 10:43:36 -0400836 WARN_ON_ONCE(rp->offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 return 0;
838 }
839 rq = container_of(rp->q.list.next, struct cache_request, q.list);
Weston Andros Adamson0db74d92012-10-23 10:43:36 -0400840 WARN_ON_ONCE(rq->q.reader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 if (rp->offset == 0)
842 rq->readers++;
843 spin_unlock(&queue_lock);
844
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +0300845 if (rq->len == 0) {
846 err = cache_request(cd, rq);
847 if (err < 0)
848 goto out;
849 rq->len = err;
850 }
851
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
853 err = -EAGAIN;
854 spin_lock(&queue_lock);
855 list_move(&rp->q.list, &rq->q.list);
856 spin_unlock(&queue_lock);
857 } else {
858 if (rp->offset + count > rq->len)
859 count = rq->len - rp->offset;
860 err = -EFAULT;
861 if (copy_to_user(buf, rq->buf + rp->offset, count))
862 goto out;
863 rp->offset += count;
864 if (rp->offset >= rq->len) {
865 rp->offset = 0;
866 spin_lock(&queue_lock);
867 list_move(&rp->q.list, &rq->q.list);
868 spin_unlock(&queue_lock);
869 }
870 err = 0;
871 }
872 out:
873 if (rp->offset == 0) {
874 /* need to release rq */
875 spin_lock(&queue_lock);
876 rq->readers--;
877 if (rq->readers == 0 &&
878 !test_bit(CACHE_PENDING, &rq->item->flags)) {
879 list_del(&rq->q.list);
880 spin_unlock(&queue_lock);
NeilBrownbaab9352006-03-27 01:15:09 -0800881 cache_put(rq->item, cd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 kfree(rq->buf);
883 kfree(rq);
884 } else
885 spin_unlock(&queue_lock);
886 }
887 if (err == -EAGAIN)
888 goto again;
Al Viro59551022016-01-22 15:40:57 -0500889 inode_unlock(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 return err ? err : count;
891}
892
Trond Myklebustda770052009-08-09 15:14:28 -0400893static ssize_t cache_do_downcall(char *kaddr, const char __user *buf,
894 size_t count, struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895{
Trond Myklebustda770052009-08-09 15:14:28 -0400896 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897
Dan Carpenter6d8d1742012-01-18 12:56:02 +0300898 if (count == 0)
899 return -EINVAL;
Trond Myklebustda770052009-08-09 15:14:28 -0400900 if (copy_from_user(kaddr, buf, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 return -EFAULT;
Trond Myklebustda770052009-08-09 15:14:28 -0400902 kaddr[count] = '\0';
903 ret = cd->cache_parse(cd, kaddr, count);
904 if (!ret)
905 ret = count;
906 return ret;
907}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
Trond Myklebustda770052009-08-09 15:14:28 -0400909static ssize_t cache_slow_downcall(const char __user *buf,
910 size_t count, struct cache_detail *cd)
911{
Roberto Bergantinos Corpas27a1e8a2020-10-19 11:33:56 +0200912 static char write_buf[32768]; /* protected by queue_io_mutex */
Trond Myklebustda770052009-08-09 15:14:28 -0400913 ssize_t ret = -EINVAL;
914
915 if (count >= sizeof(write_buf))
916 goto out;
917 mutex_lock(&queue_io_mutex);
918 ret = cache_do_downcall(write_buf, buf, count, cd);
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -0800919 mutex_unlock(&queue_io_mutex);
Trond Myklebustda770052009-08-09 15:14:28 -0400920out:
921 return ret;
922}
923
924static ssize_t cache_downcall(struct address_space *mapping,
925 const char __user *buf,
926 size_t count, struct cache_detail *cd)
927{
928 struct page *page;
929 char *kaddr;
930 ssize_t ret = -ENOMEM;
931
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300932 if (count >= PAGE_SIZE)
Trond Myklebustda770052009-08-09 15:14:28 -0400933 goto out_slow;
934
935 page = find_or_create_page(mapping, 0, GFP_KERNEL);
936 if (!page)
937 goto out_slow;
938
939 kaddr = kmap(page);
940 ret = cache_do_downcall(kaddr, buf, count, cd);
941 kunmap(page);
942 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300943 put_page(page);
Trond Myklebustda770052009-08-09 15:14:28 -0400944 return ret;
945out_slow:
946 return cache_slow_downcall(buf, count, cd);
947}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948
Trond Myklebust173912a2009-08-09 15:14:29 -0400949static ssize_t cache_write(struct file *filp, const char __user *buf,
950 size_t count, loff_t *ppos,
951 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952{
Trond Myklebustda770052009-08-09 15:14:28 -0400953 struct address_space *mapping = filp->f_mapping;
Al Viro496ad9a2013-01-23 17:07:38 -0500954 struct inode *inode = file_inode(filp);
Trond Myklebustda770052009-08-09 15:14:28 -0400955 ssize_t ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956
Trond Myklebustda770052009-08-09 15:14:28 -0400957 if (!cd->cache_parse)
958 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959
Al Viro59551022016-01-22 15:40:57 -0500960 inode_lock(inode);
Trond Myklebustda770052009-08-09 15:14:28 -0400961 ret = cache_downcall(mapping, buf, count, cd);
Al Viro59551022016-01-22 15:40:57 -0500962 inode_unlock(inode);
Trond Myklebustda770052009-08-09 15:14:28 -0400963out:
964 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965}
966
967static DECLARE_WAIT_QUEUE_HEAD(queue_wait);
968
Al Viroade994f2017-07-03 00:01:49 -0400969static __poll_t cache_poll(struct file *filp, poll_table *wait,
Trond Myklebust173912a2009-08-09 15:14:29 -0400970 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971{
Al Viroade994f2017-07-03 00:01:49 -0400972 __poll_t mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 struct cache_reader *rp = filp->private_data;
974 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975
976 poll_wait(filp, &queue_wait, wait);
977
978 /* alway allow write */
Linus Torvaldsa9a08842018-02-11 14:34:03 -0800979 mask = EPOLLOUT | EPOLLWRNORM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980
981 if (!rp)
982 return mask;
983
984 spin_lock(&queue_lock);
985
986 for (cq= &rp->q; &cq->list != &cd->queue;
987 cq = list_entry(cq->list.next, struct cache_queue, list))
988 if (!cq->reader) {
Linus Torvaldsa9a08842018-02-11 14:34:03 -0800989 mask |= EPOLLIN | EPOLLRDNORM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 break;
991 }
992 spin_unlock(&queue_lock);
993 return mask;
994}
995
Trond Myklebust173912a2009-08-09 15:14:29 -0400996static int cache_ioctl(struct inode *ino, struct file *filp,
997 unsigned int cmd, unsigned long arg,
998 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999{
1000 int len = 0;
1001 struct cache_reader *rp = filp->private_data;
1002 struct cache_queue *cq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003
1004 if (cmd != FIONREAD || !rp)
1005 return -EINVAL;
1006
1007 spin_lock(&queue_lock);
1008
1009 /* only find the length remaining in current request,
1010 * or the length of the next request
1011 */
1012 for (cq= &rp->q; &cq->list != &cd->queue;
1013 cq = list_entry(cq->list.next, struct cache_queue, list))
1014 if (!cq->reader) {
1015 struct cache_request *cr =
1016 container_of(cq, struct cache_request, q);
1017 len = cr->len - rp->offset;
1018 break;
1019 }
1020 spin_unlock(&queue_lock);
1021
1022 return put_user(len, (int __user *)arg);
1023}
1024
Trond Myklebust173912a2009-08-09 15:14:29 -04001025static int cache_open(struct inode *inode, struct file *filp,
1026 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027{
1028 struct cache_reader *rp = NULL;
1029
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001030 if (!cd || !try_module_get(cd->owner))
1031 return -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032 nonseekable_open(inode, filp);
1033 if (filp->f_mode & FMODE_READ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 rp = kmalloc(sizeof(*rp), GFP_KERNEL);
Alexey Khoroshilova7823c72013-03-23 00:36:44 +04001035 if (!rp) {
1036 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 return -ENOMEM;
Alexey Khoroshilova7823c72013-03-23 00:36:44 +04001038 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 rp->offset = 0;
1040 rp->q.reader = 1;
Dave Wysochanski64a38e82019-07-26 18:33:01 -04001041
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 spin_lock(&queue_lock);
1043 list_add(&rp->q.list, &cd->queue);
1044 spin_unlock(&queue_lock);
1045 }
Dave Wysochanski64a38e82019-07-26 18:33:01 -04001046 if (filp->f_mode & FMODE_WRITE)
1047 atomic_inc(&cd->writers);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 filp->private_data = rp;
1049 return 0;
1050}
1051
Trond Myklebust173912a2009-08-09 15:14:29 -04001052static int cache_release(struct inode *inode, struct file *filp,
1053 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054{
1055 struct cache_reader *rp = filp->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056
1057 if (rp) {
1058 spin_lock(&queue_lock);
1059 if (rp->offset) {
1060 struct cache_queue *cq;
1061 for (cq= &rp->q; &cq->list != &cd->queue;
1062 cq = list_entry(cq->list.next, struct cache_queue, list))
1063 if (!cq->reader) {
1064 container_of(cq, struct cache_request, q)
1065 ->readers--;
1066 break;
1067 }
1068 rp->offset = 0;
1069 }
1070 list_del(&rp->q.list);
1071 spin_unlock(&queue_lock);
1072
1073 filp->private_data = NULL;
1074 kfree(rp);
1075
Dave Wysochanski64a38e82019-07-26 18:33:01 -04001076 }
1077 if (filp->f_mode & FMODE_WRITE) {
1078 atomic_dec(&cd->writers);
NeilBrownc5b29f82010-08-12 16:55:22 +10001079 cd->last_close = seconds_since_boot();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080 }
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001081 module_put(cd->owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 return 0;
1083}
1084
1085
1086
NeilBrownf866a812009-08-04 15:22:38 +10001087static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088{
NeilBrownf9e1aed2013-06-13 12:53:42 +10001089 struct cache_queue *cq, *tmp;
1090 struct cache_request *cr;
1091 struct list_head dequeued;
1092
1093 INIT_LIST_HEAD(&dequeued);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 spin_lock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001095 list_for_each_entry_safe(cq, tmp, &detail->queue, list)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 if (!cq->reader) {
NeilBrownf9e1aed2013-06-13 12:53:42 +10001097 cr = container_of(cq, struct cache_request, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 if (cr->item != ch)
1099 continue;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001100 if (test_bit(CACHE_PENDING, &ch->flags))
1101 /* Lost a race and it is pending again */
1102 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 if (cr->readers != 0)
NeilBrown4013ede2006-03-27 01:15:07 -08001104 continue;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001105 list_move(&cr->q.list, &dequeued);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 }
1107 spin_unlock(&queue_lock);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001108 while (!list_empty(&dequeued)) {
1109 cr = list_entry(dequeued.next, struct cache_request, q.list);
1110 list_del(&cr->q.list);
1111 cache_put(cr->item, detail);
1112 kfree(cr->buf);
1113 kfree(cr);
1114 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115}
1116
1117/*
1118 * Support routines for text-based upcalls.
1119 * Fields are separated by spaces.
1120 * Fields are either mangled to quote space tab newline slosh with slosh
1121 * or a hexified with a leading \x
1122 * Record is terminated with newline.
1123 *
1124 */
1125
1126void qword_add(char **bpp, int *lp, char *str)
1127{
1128 char *bp = *bpp;
1129 int len = *lp;
Andy Shevchenko1b2e1222014-11-28 17:50:28 +02001130 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131
1132 if (len < 0) return;
1133
Rasmus Villemoes41416f22015-04-15 16:17:28 -07001134 ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
1135 if (ret >= len) {
1136 bp += len;
Andy Shevchenko1b2e1222014-11-28 17:50:28 +02001137 len = -1;
Rasmus Villemoes41416f22015-04-15 16:17:28 -07001138 } else {
1139 bp += ret;
Andy Shevchenko1b2e1222014-11-28 17:50:28 +02001140 len -= ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 *bp++ = ' ';
1142 len--;
1143 }
1144 *bpp = bp;
1145 *lp = len;
1146}
Trond Myklebust24c37672008-12-23 16:30:12 -05001147EXPORT_SYMBOL_GPL(qword_add);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
1149void qword_addhex(char **bpp, int *lp, char *buf, int blen)
1150{
1151 char *bp = *bpp;
1152 int len = *lp;
1153
1154 if (len < 0) return;
1155
1156 if (len > 2) {
1157 *bp++ = '\\';
1158 *bp++ = 'x';
1159 len -= 2;
1160 while (blen && len >= 2) {
Andy Shevchenko056785e2013-12-12 15:49:21 +02001161 bp = hex_byte_pack(bp, *buf++);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162 len -= 2;
1163 blen--;
1164 }
1165 }
1166 if (blen || len<1) len = -1;
1167 else {
1168 *bp++ = ' ';
1169 len--;
1170 }
1171 *bpp = bp;
1172 *lp = len;
1173}
Trond Myklebust24c37672008-12-23 16:30:12 -05001174EXPORT_SYMBOL_GPL(qword_addhex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175
1176static void warn_no_listener(struct cache_detail *detail)
1177{
1178 if (detail->last_warn != detail->last_close) {
1179 detail->last_warn = detail->last_close;
1180 if (detail->warn_no_listener)
Trond Myklebust2da8ca22009-08-09 15:14:26 -04001181 detail->warn_no_listener(detail, detail->last_close != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 }
1183}
1184
J. Bruce Fields06497522010-09-19 22:55:06 -04001185static bool cache_listeners_exist(struct cache_detail *detail)
1186{
Dave Wysochanski64a38e82019-07-26 18:33:01 -04001187 if (atomic_read(&detail->writers))
J. Bruce Fields06497522010-09-19 22:55:06 -04001188 return true;
1189 if (detail->last_close == 0)
1190 /* This cache was never opened */
1191 return false;
1192 if (detail->last_close < seconds_since_boot() - 30)
1193 /*
1194 * We allow for the possibility that someone might
1195 * restart a userspace daemon without restarting the
1196 * server; but after 30 seconds, we give up.
1197 */
1198 return false;
1199 return true;
1200}
1201
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202/*
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001203 * register an upcall request to user-space and queue it up for read() by the
1204 * upcall daemon.
1205 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 * Each request is at most one page long.
1207 */
Trond Myklebust65286b82020-03-01 18:21:42 -05001208static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 char *buf;
1211 struct cache_request *crq;
NeilBrownf9e1aed2013-06-13 12:53:42 +10001212 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213
NeilBrown013920e2013-06-13 12:53:42 +10001214 if (test_bit(CACHE_CLEANED, &h->flags))
1215 /* Too late to make an upcall */
1216 return -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217
1218 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1219 if (!buf)
1220 return -EAGAIN;
1221
1222 crq = kmalloc(sizeof (*crq), GFP_KERNEL);
1223 if (!crq) {
1224 kfree(buf);
1225 return -EAGAIN;
1226 }
1227
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 crq->q.reader = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 crq->buf = buf;
Stanislav Kinsburskyd94af6d2013-02-04 14:03:03 +03001230 crq->len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 crq->readers = 0;
1232 spin_lock(&queue_lock);
NeilBrowna6ab1e82016-03-04 17:20:13 +11001233 if (test_bit(CACHE_PENDING, &h->flags)) {
1234 crq->item = cache_get(h);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001235 list_add_tail(&crq->q.list, &detail->queue);
Trond Myklebust78a947f2020-03-01 18:21:44 -05001236 trace_cache_entry_upcall(detail, h);
NeilBrowna6ab1e82016-03-04 17:20:13 +11001237 } else
NeilBrownf9e1aed2013-06-13 12:53:42 +10001238 /* Lost a race, no longer PENDING, so don't enqueue */
1239 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 spin_unlock(&queue_lock);
1241 wake_up(&queue_wait);
NeilBrownf9e1aed2013-06-13 12:53:42 +10001242 if (ret == -EAGAIN) {
1243 kfree(buf);
1244 kfree(crq);
1245 }
1246 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247}
Trond Myklebust65286b82020-03-01 18:21:42 -05001248
1249int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
1250{
1251 if (test_and_set_bit(CACHE_PENDING, &h->flags))
1252 return 0;
1253 return cache_pipe_upcall(detail, h);
1254}
Trond Myklebustbc74b4f2009-08-09 15:14:29 -04001255EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256
Trond Myklebust65286b82020-03-01 18:21:42 -05001257int sunrpc_cache_pipe_upcall_timeout(struct cache_detail *detail,
1258 struct cache_head *h)
1259{
1260 if (!cache_listeners_exist(detail)) {
1261 warn_no_listener(detail);
Trond Myklebust78a947f2020-03-01 18:21:44 -05001262 trace_cache_entry_no_listener(detail, h);
Trond Myklebust65286b82020-03-01 18:21:42 -05001263 return -EINVAL;
1264 }
1265 return sunrpc_cache_pipe_upcall(detail, h);
1266}
1267EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall_timeout);
1268
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269/*
1270 * parse a message from user-space and pass it
1271 * to an appropriate cache
1272 * Messages are, like requests, separated into fields by
1273 * spaces and dequotes as \xHEXSTRING or embedded \nnn octal
1274 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001275 * Message is
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 * reply cachename expiry key ... content....
1277 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001278 * key and content are both parsed by cache
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 */
1280
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281int qword_get(char **bpp, char *dest, int bufsize)
1282{
1283 /* return bytes copied, or -1 on error */
1284 char *bp = *bpp;
1285 int len = 0;
1286
1287 while (*bp == ' ') bp++;
1288
1289 if (bp[0] == '\\' && bp[1] == 'x') {
1290 /* HEX STRING */
1291 bp += 2;
Stefan Hajnoczib7052cd2016-02-18 18:55:54 +00001292 while (len < bufsize - 1) {
Andy Shevchenkoe7f483ea2010-09-21 09:40:25 +03001293 int h, l;
1294
1295 h = hex_to_bin(bp[0]);
1296 if (h < 0)
1297 break;
1298
1299 l = hex_to_bin(bp[1]);
1300 if (l < 0)
1301 break;
1302
1303 *dest++ = (h << 4) | l;
1304 bp += 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 len++;
1306 }
1307 } else {
1308 /* text with \nnn octal quoting */
1309 while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) {
1310 if (*bp == '\\' &&
1311 isodigit(bp[1]) && (bp[1] <= '3') &&
1312 isodigit(bp[2]) &&
1313 isodigit(bp[3])) {
1314 int byte = (*++bp -'0');
1315 bp++;
1316 byte = (byte << 3) | (*bp++ - '0');
1317 byte = (byte << 3) | (*bp++ - '0');
1318 *dest++ = byte;
1319 len++;
1320 } else {
1321 *dest++ = *bp++;
1322 len++;
1323 }
1324 }
1325 }
1326
1327 if (*bp != ' ' && *bp != '\n' && *bp != '\0')
1328 return -1;
1329 while (*bp == ' ') bp++;
1330 *bpp = bp;
1331 *dest = '\0';
1332 return len;
1333}
Trond Myklebust24c37672008-12-23 16:30:12 -05001334EXPORT_SYMBOL_GPL(qword_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335
1336
1337/*
Kinglong Mee6489a8f2017-02-07 21:49:17 +08001338 * support /proc/net/rpc/$CACHENAME/content
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 * as a seqfile.
1340 * We call ->cache_show passing NULL for the item to
1341 * get a header, then pass each real item in the cache
1342 */
1343
Trond Myklebustae741362018-10-03 12:01:22 -04001344static void *__cache_seq_start(struct seq_file *m, loff_t *pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345{
1346 loff_t n = *pos;
Eric Dumazet95c96172012-04-15 05:58:06 +00001347 unsigned int hash, entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 struct cache_head *ch;
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001349 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 if (!n--)
1352 return SEQ_START_TOKEN;
1353 hash = n >> 32;
1354 entry = n & ((1LL<<32) - 1);
1355
Trond Myklebustae741362018-10-03 12:01:22 -04001356 hlist_for_each_entry_rcu(ch, &cd->hash_table[hash], cache_list)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 if (!entry--)
1358 return ch;
1359 n &= ~((1LL<<32) - 1);
1360 do {
1361 hash++;
1362 n += 1LL<<32;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001363 } while(hash < cd->hash_size &&
Kinglong Mee129e5822015-07-27 11:10:15 +08001364 hlist_empty(&cd->hash_table[hash]));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 if (hash >= cd->hash_size)
1366 return NULL;
1367 *pos = n+1;
Trond Myklebustae741362018-10-03 12:01:22 -04001368 return hlist_entry_safe(rcu_dereference_raw(
1369 hlist_first_rcu(&cd->hash_table[hash])),
Kinglong Mee129e5822015-07-27 11:10:15 +08001370 struct cache_head, cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371}
Trond Myklebustae741362018-10-03 12:01:22 -04001372
Trond Myklebustd48cf352018-10-01 10:41:51 -04001373static void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374{
1375 struct cache_head *ch = p;
1376 int hash = (*pos >> 32);
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001377 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378
1379 if (p == SEQ_START_TOKEN)
1380 hash = 0;
Kinglong Mee129e5822015-07-27 11:10:15 +08001381 else if (ch->cache_list.next == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 hash++;
1383 *pos += 1LL<<32;
1384 } else {
1385 ++*pos;
Trond Myklebustae741362018-10-03 12:01:22 -04001386 return hlist_entry_safe(rcu_dereference_raw(
1387 hlist_next_rcu(&ch->cache_list)),
Kinglong Mee129e5822015-07-27 11:10:15 +08001388 struct cache_head, cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 }
1390 *pos &= ~((1LL<<32) - 1);
1391 while (hash < cd->hash_size &&
Kinglong Mee129e5822015-07-27 11:10:15 +08001392 hlist_empty(&cd->hash_table[hash])) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393 hash++;
1394 *pos += 1LL<<32;
1395 }
1396 if (hash >= cd->hash_size)
1397 return NULL;
1398 ++*pos;
Trond Myklebustae741362018-10-03 12:01:22 -04001399 return hlist_entry_safe(rcu_dereference_raw(
1400 hlist_first_rcu(&cd->hash_table[hash])),
Kinglong Mee129e5822015-07-27 11:10:15 +08001401 struct cache_head, cache_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402}
1403
Trond Myklebustae741362018-10-03 12:01:22 -04001404void *cache_seq_start_rcu(struct seq_file *m, loff_t *pos)
1405 __acquires(RCU)
1406{
1407 rcu_read_lock();
1408 return __cache_seq_start(m, pos);
1409}
1410EXPORT_SYMBOL_GPL(cache_seq_start_rcu);
1411
1412void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos)
1413{
1414 return cache_seq_next(file, p, pos);
1415}
1416EXPORT_SYMBOL_GPL(cache_seq_next_rcu);
1417
1418void cache_seq_stop_rcu(struct seq_file *m, void *p)
1419 __releases(RCU)
1420{
1421 rcu_read_unlock();
1422}
1423EXPORT_SYMBOL_GPL(cache_seq_stop_rcu);
1424
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425static int c_show(struct seq_file *m, void *p)
1426{
1427 struct cache_head *cp = p;
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001428 struct cache_detail *cd = m->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429
1430 if (p == SEQ_START_TOKEN)
1431 return cd->cache_show(m, cd, NULL);
1432
1433 ifdebug(CACHE)
Arnd Bergmannf5599352017-10-20 16:34:42 +02001434 seq_printf(m, "# expiry=%lld refcnt=%d flags=%lx\n",
NeilBrownc5b29f82010-08-12 16:55:22 +10001435 convert_to_wallclock(cp->expiry_time),
Peter Zijlstra2c935bc2016-11-14 17:29:48 +01001436 kref_read(&cp->ref), cp->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437 cache_get(cp);
1438 if (cache_check(cd, cp, NULL))
1439 /* cache_check does a cache_put on failure */
Xu Wang9dbc1f42020-09-16 05:39:18 +00001440 seq_puts(m, "# ");
NeilBrown200724a2012-07-12 10:37:34 +10001441 else {
1442 if (cache_is_expired(cd, cp))
Xu Wang9dbc1f42020-09-16 05:39:18 +00001443 seq_puts(m, "# ");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 cache_put(cp, cd);
NeilBrown200724a2012-07-12 10:37:34 +10001445 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446
1447 return cd->cache_show(m, cd, cp);
1448}
1449
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001450static const struct seq_operations cache_content_op = {
Trond Myklebustd48cf352018-10-01 10:41:51 -04001451 .start = cache_seq_start_rcu,
1452 .next = cache_seq_next_rcu,
1453 .stop = cache_seq_stop_rcu,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 .show = c_show,
1455};
1456
Trond Myklebust173912a2009-08-09 15:14:29 -04001457static int content_open(struct inode *inode, struct file *file,
1458 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459{
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001460 struct seq_file *seq;
1461 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001463 if (!cd || !try_module_get(cd->owner))
1464 return -EACCES;
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001465
1466 err = seq_open(file, &cache_content_op);
1467 if (err) {
Li Zefana5990ea2010-03-11 14:08:10 -08001468 module_put(cd->owner);
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001469 return err;
Li Zefana5990ea2010-03-11 14:08:10 -08001470 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001472 seq = file->private_data;
1473 seq->private = cd;
Pavel Emelyanovec931032007-10-10 02:31:07 -07001474 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001475}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001477static int content_release(struct inode *inode, struct file *file,
1478 struct cache_detail *cd)
1479{
Kinglong Mee9936f2a2015-07-27 11:09:10 +08001480 int ret = seq_release(inode, file);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001481 module_put(cd->owner);
1482 return ret;
1483}
1484
1485static int open_flush(struct inode *inode, struct file *file,
1486 struct cache_detail *cd)
1487{
1488 if (!cd || !try_module_get(cd->owner))
1489 return -EACCES;
1490 return nonseekable_open(inode, file);
1491}
1492
1493static int release_flush(struct inode *inode, struct file *file,
1494 struct cache_detail *cd)
1495{
1496 module_put(cd->owner);
1497 return 0;
1498}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499
1500static ssize_t read_flush(struct file *file, char __user *buf,
Trond Myklebust173912a2009-08-09 15:14:29 -04001501 size_t count, loff_t *ppos,
1502 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503{
Sasha Levin212ba902012-07-17 00:01:26 +02001504 char tbuf[22];
Chuck Lever01b29692007-10-26 13:31:20 -04001505 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506
Arnd Bergmannf5599352017-10-20 16:34:42 +02001507 len = snprintf(tbuf, sizeof(tbuf), "%llu\n",
Kinglong Mee8ccc8692017-02-07 21:50:32 +08001508 convert_to_wallclock(cd->flush_time));
1509 return simple_read_from_buffer(buf, count, ppos, tbuf, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510}
1511
Trond Myklebust173912a2009-08-09 15:14:29 -04001512static ssize_t write_flush(struct file *file, const char __user *buf,
1513 size_t count, loff_t *ppos,
1514 struct cache_detail *cd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516 char tbuf[20];
NeilBrown3b68e6e2018-02-14 12:15:06 +11001517 char *ep;
Arnd Bergmannf5599352017-10-20 16:34:42 +02001518 time64_t now;
NeilBrownc5b29f82010-08-12 16:55:22 +10001519
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 if (*ppos || count > sizeof(tbuf)-1)
1521 return -EINVAL;
1522 if (copy_from_user(tbuf, buf, count))
1523 return -EFAULT;
1524 tbuf[count] = 0;
NeilBrownc5b29f82010-08-12 16:55:22 +10001525 simple_strtoul(tbuf, &ep, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 if (*ep && *ep != '\n')
1527 return -EINVAL;
NeilBrown3b68e6e2018-02-14 12:15:06 +11001528 /* Note that while we check that 'buf' holds a valid number,
1529 * we always ignore the value and just flush everything.
1530 * Making use of the number leads to races.
Neil Brown77862032015-10-16 08:59:08 +11001531 */
Neil Brown77862032015-10-16 08:59:08 +11001532
NeilBrown3b68e6e2018-02-14 12:15:06 +11001533 now = seconds_since_boot();
1534 /* Always flush everything, so behave like cache_purge()
1535 * Do this by advancing flush_time to the current time,
1536 * or by one second if it has already reached the current time.
1537 * Newly added cache entries will always have ->last_refresh greater
1538 * that ->flush_time, so they don't get flushed prematurely.
1539 */
1540
1541 if (cd->flush_time >= now)
1542 now = cd->flush_time + 1;
1543
1544 cd->flush_time = now;
1545 cd->nextcheck = now;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 cache_flush();
1547
Jeff Laytonf69d6d82019-08-18 14:18:44 -04001548 if (cd->flush)
1549 cd->flush();
1550
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551 *ppos += count;
1552 return count;
1553}
1554
Trond Myklebust173912a2009-08-09 15:14:29 -04001555static ssize_t cache_read_procfs(struct file *filp, char __user *buf,
1556 size_t count, loff_t *ppos)
1557{
Al Virod9dda782013-03-31 18:16:14 -04001558 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001559
1560 return cache_read(filp, buf, count, ppos, cd);
1561}
1562
1563static ssize_t cache_write_procfs(struct file *filp, const 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 cache_write(filp, buf, count, ppos, cd);
1569}
1570
Al Viroade994f2017-07-03 00:01:49 -04001571static __poll_t cache_poll_procfs(struct file *filp, poll_table *wait)
Trond Myklebust173912a2009-08-09 15:14:29 -04001572{
Al Virod9dda782013-03-31 18:16:14 -04001573 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001574
1575 return cache_poll(filp, wait, cd);
1576}
1577
Frederic Weisbeckerd79b6f42010-03-30 07:27:50 +02001578static long cache_ioctl_procfs(struct file *filp,
1579 unsigned int cmd, unsigned long arg)
Trond Myklebust173912a2009-08-09 15:14:29 -04001580{
Al Viro496ad9a2013-01-23 17:07:38 -05001581 struct inode *inode = file_inode(filp);
Al Virod9dda782013-03-31 18:16:14 -04001582 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001583
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001584 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001585}
1586
1587static int cache_open_procfs(struct inode *inode, struct file *filp)
1588{
Al Virod9dda782013-03-31 18:16:14 -04001589 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001590
1591 return cache_open(inode, filp, cd);
1592}
1593
1594static int cache_release_procfs(struct inode *inode, struct file *filp)
1595{
Al Virod9dda782013-03-31 18:16:14 -04001596 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001597
1598 return cache_release(inode, filp, cd);
1599}
1600
Alexey Dobriyan97a32532020-02-03 17:37:17 -08001601static const struct proc_ops cache_channel_proc_ops = {
1602 .proc_lseek = no_llseek,
1603 .proc_read = cache_read_procfs,
1604 .proc_write = cache_write_procfs,
1605 .proc_poll = cache_poll_procfs,
1606 .proc_ioctl = cache_ioctl_procfs, /* for FIONREAD */
1607 .proc_open = cache_open_procfs,
1608 .proc_release = cache_release_procfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609};
Trond Myklebust173912a2009-08-09 15:14:29 -04001610
1611static int content_open_procfs(struct inode *inode, struct file *filp)
1612{
Al Virod9dda782013-03-31 18:16:14 -04001613 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebust173912a2009-08-09 15:14:29 -04001614
1615 return content_open(inode, filp, cd);
1616}
1617
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001618static int content_release_procfs(struct inode *inode, struct file *filp)
1619{
Al Virod9dda782013-03-31 18:16:14 -04001620 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001621
1622 return content_release(inode, filp, cd);
1623}
1624
Alexey Dobriyan97a32532020-02-03 17:37:17 -08001625static const struct proc_ops content_proc_ops = {
1626 .proc_open = content_open_procfs,
1627 .proc_read = seq_read,
1628 .proc_lseek = seq_lseek,
1629 .proc_release = content_release_procfs,
Trond Myklebust173912a2009-08-09 15:14:29 -04001630};
1631
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001632static int open_flush_procfs(struct inode *inode, struct file *filp)
1633{
Al Virod9dda782013-03-31 18:16:14 -04001634 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001635
1636 return open_flush(inode, filp, cd);
1637}
1638
1639static int release_flush_procfs(struct inode *inode, struct file *filp)
1640{
Al Virod9dda782013-03-31 18:16:14 -04001641 struct cache_detail *cd = PDE_DATA(inode);
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001642
1643 return release_flush(inode, filp, cd);
1644}
1645
Trond Myklebust173912a2009-08-09 15:14:29 -04001646static ssize_t read_flush_procfs(struct file *filp, char __user *buf,
1647 size_t count, loff_t *ppos)
1648{
Al Virod9dda782013-03-31 18:16:14 -04001649 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001650
1651 return read_flush(filp, buf, count, ppos, cd);
1652}
1653
1654static ssize_t write_flush_procfs(struct file *filp,
1655 const char __user *buf,
1656 size_t count, loff_t *ppos)
1657{
Al Virod9dda782013-03-31 18:16:14 -04001658 struct cache_detail *cd = PDE_DATA(file_inode(filp));
Trond Myklebust173912a2009-08-09 15:14:29 -04001659
1660 return write_flush(filp, buf, count, ppos, cd);
1661}
1662
Alexey Dobriyan97a32532020-02-03 17:37:17 -08001663static const struct proc_ops cache_flush_proc_ops = {
1664 .proc_open = open_flush_procfs,
1665 .proc_read = read_flush_procfs,
1666 .proc_write = write_flush_procfs,
1667 .proc_release = release_flush_procfs,
1668 .proc_lseek = no_llseek,
Trond Myklebust173912a2009-08-09 15:14:29 -04001669};
1670
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001671static void remove_cache_proc_entries(struct cache_detail *cd)
Trond Myklebust173912a2009-08-09 15:14:29 -04001672{
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001673 if (cd->procfs) {
1674 proc_remove(cd->procfs);
1675 cd->procfs = NULL;
1676 }
Trond Myklebust173912a2009-08-09 15:14:29 -04001677}
1678
1679#ifdef CONFIG_PROC_FS
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001680static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001681{
1682 struct proc_dir_entry *p;
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001683 struct sunrpc_net *sn;
Trond Myklebust173912a2009-08-09 15:14:29 -04001684
Pavel Emelyanov4f42d0d2010-09-27 14:01:58 +04001685 sn = net_generic(net, sunrpc_net_id);
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001686 cd->procfs = proc_mkdir(cd->name, sn->proc_net_rpc);
1687 if (cd->procfs == NULL)
Trond Myklebust173912a2009-08-09 15:14:29 -04001688 goto out_nomem;
Trond Myklebust173912a2009-08-09 15:14:29 -04001689
Joe Perchesd6444062018-03-23 15:54:38 -07001690 p = proc_create_data("flush", S_IFREG | 0600,
Alexey Dobriyan97a32532020-02-03 17:37:17 -08001691 cd->procfs, &cache_flush_proc_ops, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001692 if (p == NULL)
1693 goto out_nomem;
1694
Stanislav Kinsbursky2d438332013-02-04 14:02:50 +03001695 if (cd->cache_request || cd->cache_parse) {
Joe Perchesd6444062018-03-23 15:54:38 -07001696 p = proc_create_data("channel", S_IFREG | 0600, cd->procfs,
Alexey Dobriyan97a32532020-02-03 17:37:17 -08001697 &cache_channel_proc_ops, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001698 if (p == NULL)
1699 goto out_nomem;
1700 }
1701 if (cd->cache_show) {
Joe Perchesd6444062018-03-23 15:54:38 -07001702 p = proc_create_data("content", S_IFREG | 0400, cd->procfs,
Alexey Dobriyan97a32532020-02-03 17:37:17 -08001703 &content_proc_ops, cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001704 if (p == NULL)
1705 goto out_nomem;
1706 }
1707 return 0;
1708out_nomem:
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001709 remove_cache_proc_entries(cd);
Trond Myklebust173912a2009-08-09 15:14:29 -04001710 return -ENOMEM;
1711}
1712#else /* CONFIG_PROC_FS */
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001713static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001714{
1715 return 0;
1716}
1717#endif
1718
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001719void __init cache_initialize(void)
1720{
Tejun Heo203b42f72012-08-21 13:18:23 -07001721 INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean);
Artem Bityutskiy8eab9452010-07-01 18:05:56 +03001722}
1723
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001724int cache_register_net(struct cache_detail *cd, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001725{
1726 int ret;
1727
1728 sunrpc_init_cache_detail(cd);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001729 ret = create_cache_proc_entries(cd, net);
Trond Myklebust173912a2009-08-09 15:14:29 -04001730 if (ret)
1731 sunrpc_destroy_cache_detail(cd);
1732 return ret;
1733}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001734EXPORT_SYMBOL_GPL(cache_register_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001735
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001736void cache_unregister_net(struct cache_detail *cd, struct net *net)
1737{
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001738 remove_cache_proc_entries(cd);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001739 sunrpc_destroy_cache_detail(cd);
1740}
Stanislav Kinsburskyf5c8593b2011-12-07 12:57:56 +03001741EXPORT_SYMBOL_GPL(cache_unregister_net);
Pavel Emelyanov593ce162010-09-27 14:00:15 +04001742
Bhumika Goyald34971a2017-10-17 18:14:23 +02001743struct cache_detail *cache_create_net(const struct cache_detail *tmpl, struct net *net)
Trond Myklebust173912a2009-08-09 15:14:29 -04001744{
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001745 struct cache_detail *cd;
Kinglong Mee129e5822015-07-27 11:10:15 +08001746 int i;
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001747
1748 cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
1749 if (cd == NULL)
1750 return ERR_PTR(-ENOMEM);
1751
Kees Cook6396bb22018-06-12 14:03:40 -07001752 cd->hash_table = kcalloc(cd->hash_size, sizeof(struct hlist_head),
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001753 GFP_KERNEL);
1754 if (cd->hash_table == NULL) {
1755 kfree(cd);
1756 return ERR_PTR(-ENOMEM);
1757 }
Kinglong Mee129e5822015-07-27 11:10:15 +08001758
1759 for (i = 0; i < cd->hash_size; i++)
1760 INIT_HLIST_HEAD(&cd->hash_table[i]);
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001761 cd->net = net;
1762 return cd;
Trond Myklebust173912a2009-08-09 15:14:29 -04001763}
Stanislav Kinsbursky0a402d5a2012-01-19 21:42:21 +04001764EXPORT_SYMBOL_GPL(cache_create_net);
1765
1766void cache_destroy_net(struct cache_detail *cd, struct net *net)
1767{
1768 kfree(cd->hash_table);
1769 kfree(cd);
1770}
1771EXPORT_SYMBOL_GPL(cache_destroy_net);
Trond Myklebust8854e822009-08-09 15:14:30 -04001772
1773static ssize_t cache_read_pipefs(struct file *filp, char __user *buf,
1774 size_t count, loff_t *ppos)
1775{
Al Viro496ad9a2013-01-23 17:07:38 -05001776 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001777
1778 return cache_read(filp, buf, count, ppos, cd);
1779}
1780
1781static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf,
1782 size_t count, loff_t *ppos)
1783{
Al Viro496ad9a2013-01-23 17:07:38 -05001784 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001785
1786 return cache_write(filp, buf, count, ppos, cd);
1787}
1788
Al Viroade994f2017-07-03 00:01:49 -04001789static __poll_t cache_poll_pipefs(struct file *filp, poll_table *wait)
Trond Myklebust8854e822009-08-09 15:14:30 -04001790{
Al Viro496ad9a2013-01-23 17:07:38 -05001791 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001792
1793 return cache_poll(filp, wait, cd);
1794}
1795
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001796static long cache_ioctl_pipefs(struct file *filp,
Trond Myklebust8854e822009-08-09 15:14:30 -04001797 unsigned int cmd, unsigned long arg)
1798{
Al Viro496ad9a2013-01-23 17:07:38 -05001799 struct inode *inode = file_inode(filp);
Trond Myklebust8854e822009-08-09 15:14:30 -04001800 struct cache_detail *cd = RPC_I(inode)->private;
1801
Arnd Bergmanna6f8dbc2010-10-04 21:18:23 +02001802 return cache_ioctl(inode, filp, cmd, arg, cd);
Trond Myklebust8854e822009-08-09 15:14:30 -04001803}
1804
1805static int cache_open_pipefs(struct inode *inode, struct file *filp)
1806{
1807 struct cache_detail *cd = RPC_I(inode)->private;
1808
1809 return cache_open(inode, filp, cd);
1810}
1811
1812static int cache_release_pipefs(struct inode *inode, struct file *filp)
1813{
1814 struct cache_detail *cd = RPC_I(inode)->private;
1815
1816 return cache_release(inode, filp, cd);
1817}
1818
1819const struct file_operations cache_file_operations_pipefs = {
1820 .owner = THIS_MODULE,
1821 .llseek = no_llseek,
1822 .read = cache_read_pipefs,
1823 .write = cache_write_pipefs,
1824 .poll = cache_poll_pipefs,
Frederic Weisbecker9918ff22010-05-19 15:08:17 +02001825 .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */
Trond Myklebust8854e822009-08-09 15:14:30 -04001826 .open = cache_open_pipefs,
1827 .release = cache_release_pipefs,
1828};
1829
1830static int content_open_pipefs(struct inode *inode, struct file *filp)
1831{
1832 struct cache_detail *cd = RPC_I(inode)->private;
1833
1834 return content_open(inode, filp, cd);
1835}
1836
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001837static int content_release_pipefs(struct inode *inode, struct file *filp)
1838{
1839 struct cache_detail *cd = RPC_I(inode)->private;
1840
1841 return content_release(inode, filp, cd);
1842}
1843
Trond Myklebust8854e822009-08-09 15:14:30 -04001844const struct file_operations content_file_operations_pipefs = {
1845 .open = content_open_pipefs,
1846 .read = seq_read,
1847 .llseek = seq_lseek,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001848 .release = content_release_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001849};
1850
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001851static int open_flush_pipefs(struct inode *inode, struct file *filp)
1852{
1853 struct cache_detail *cd = RPC_I(inode)->private;
1854
1855 return open_flush(inode, filp, cd);
1856}
1857
1858static int release_flush_pipefs(struct inode *inode, struct file *filp)
1859{
1860 struct cache_detail *cd = RPC_I(inode)->private;
1861
1862 return release_flush(inode, filp, cd);
1863}
1864
Trond Myklebust8854e822009-08-09 15:14:30 -04001865static ssize_t read_flush_pipefs(struct file *filp, char __user *buf,
1866 size_t count, loff_t *ppos)
1867{
Al Viro496ad9a2013-01-23 17:07:38 -05001868 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001869
1870 return read_flush(filp, buf, count, ppos, cd);
1871}
1872
1873static ssize_t write_flush_pipefs(struct file *filp,
1874 const char __user *buf,
1875 size_t count, loff_t *ppos)
1876{
Al Viro496ad9a2013-01-23 17:07:38 -05001877 struct cache_detail *cd = RPC_I(file_inode(filp))->private;
Trond Myklebust8854e822009-08-09 15:14:30 -04001878
1879 return write_flush(filp, buf, count, ppos, cd);
1880}
1881
1882const struct file_operations cache_flush_operations_pipefs = {
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001883 .open = open_flush_pipefs,
Trond Myklebust8854e822009-08-09 15:14:30 -04001884 .read = read_flush_pipefs,
1885 .write = write_flush_pipefs,
Trond Myklebustf7e86ab2009-08-19 18:13:00 -04001886 .release = release_flush_pipefs,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001887 .llseek = no_llseek,
Trond Myklebust8854e822009-08-09 15:14:30 -04001888};
1889
1890int sunrpc_cache_register_pipefs(struct dentry *parent,
Al Viro64f14262011-07-25 00:35:13 -04001891 const char *name, umode_t umode,
Trond Myklebust8854e822009-08-09 15:14:30 -04001892 struct cache_detail *cd)
1893{
Al Viroa95e6912013-07-14 16:43:54 +04001894 struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd);
1895 if (IS_ERR(dir))
1896 return PTR_ERR(dir);
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001897 cd->pipefs = dir;
Al Viroa95e6912013-07-14 16:43:54 +04001898 return 0;
Trond Myklebust8854e822009-08-09 15:14:30 -04001899}
1900EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
1901
1902void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
1903{
Kinglong Mee863d7d9c2017-02-07 21:47:16 +08001904 if (cd->pipefs) {
1905 rpc_remove_cache_dir(cd->pipefs);
1906 cd->pipefs = NULL;
1907 }
Trond Myklebust8854e822009-08-09 15:14:30 -04001908}
1909EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
1910
Neil Brown2b477c02016-12-22 12:38:06 -05001911void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h)
1912{
Trond Myklebust1863d772018-10-01 10:41:52 -04001913 spin_lock(&cd->hash_lock);
Neil Brown2b477c02016-12-22 12:38:06 -05001914 if (!hlist_unhashed(&h->cache_list)){
Trond Myklebust809fe3c52020-01-06 13:40:35 -05001915 sunrpc_begin_cache_remove_entry(h, cd);
Trond Myklebust1863d772018-10-01 10:41:52 -04001916 spin_unlock(&cd->hash_lock);
Trond Myklebust809fe3c52020-01-06 13:40:35 -05001917 sunrpc_end_cache_remove_entry(h, cd);
Neil Brown2b477c02016-12-22 12:38:06 -05001918 } else
Trond Myklebust1863d772018-10-01 10:41:52 -04001919 spin_unlock(&cd->hash_lock);
Neil Brown2b477c02016-12-22 12:38:06 -05001920}
1921EXPORT_SYMBOL_GPL(sunrpc_cache_unhash);