Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/sunrpc/cache.c |
| 3 | * |
| 4 | * Generic code for various authentication-related caches |
| 5 | * used by sunrpc clients and servers. |
| 6 | * |
| 7 | * Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au> |
| 8 | * |
| 9 | * Released under terms in GPL version 2. See COPYING. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/fs.h> |
| 15 | #include <linux/file.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/signal.h> |
| 18 | #include <linux/sched.h> |
| 19 | #include <linux/kmod.h> |
| 20 | #include <linux/list.h> |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/ctype.h> |
| 23 | #include <asm/uaccess.h> |
| 24 | #include <linux/poll.h> |
| 25 | #include <linux/seq_file.h> |
| 26 | #include <linux/proc_fs.h> |
| 27 | #include <linux/net.h> |
| 28 | #include <linux/workqueue.h> |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 29 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <asm/ioctls.h> |
| 31 | #include <linux/sunrpc/types.h> |
| 32 | #include <linux/sunrpc/cache.h> |
| 33 | #include <linux/sunrpc/stats.h> |
| 34 | |
| 35 | #define RPCDBG_FACILITY RPCDBG_CACHE |
| 36 | |
J.Bruce Fields | e0bb89e | 2006-12-13 00:35:25 -0800 | [diff] [blame] | 37 | static int cache_defer_req(struct cache_req *req, struct cache_head *item); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | static void cache_revisit_request(struct cache_head *item); |
| 39 | |
Adrian Bunk | 74cae61 | 2006-03-27 01:15:10 -0800 | [diff] [blame] | 40 | static void cache_init(struct cache_head *h) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | { |
| 42 | time_t now = get_seconds(); |
| 43 | h->next = NULL; |
| 44 | h->flags = 0; |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 45 | kref_init(&h->ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | h->expiry_time = now + CACHE_NEW_EXPIRY; |
| 47 | h->last_refresh = now; |
| 48 | } |
| 49 | |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 50 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, |
| 51 | struct cache_head *key, int hash) |
| 52 | { |
| 53 | struct cache_head **head, **hp; |
| 54 | struct cache_head *new = NULL; |
| 55 | |
| 56 | head = &detail->hash_table[hash]; |
| 57 | |
| 58 | read_lock(&detail->hash_lock); |
| 59 | |
| 60 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { |
| 61 | struct cache_head *tmp = *hp; |
| 62 | if (detail->match(tmp, key)) { |
| 63 | cache_get(tmp); |
| 64 | read_unlock(&detail->hash_lock); |
| 65 | return tmp; |
| 66 | } |
| 67 | } |
| 68 | read_unlock(&detail->hash_lock); |
| 69 | /* Didn't find anything, insert an empty entry */ |
| 70 | |
| 71 | new = detail->alloc(); |
| 72 | if (!new) |
| 73 | return NULL; |
Neil Brown | 2f34931 | 2006-08-05 12:14:29 -0700 | [diff] [blame] | 74 | /* must fully initialise 'new', else |
| 75 | * we might get lose if we need to |
| 76 | * cache_put it soon. |
| 77 | */ |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 78 | cache_init(new); |
Neil Brown | 2f34931 | 2006-08-05 12:14:29 -0700 | [diff] [blame] | 79 | detail->init(new, key); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 80 | |
| 81 | write_lock(&detail->hash_lock); |
| 82 | |
| 83 | /* check if entry appeared while we slept */ |
| 84 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { |
| 85 | struct cache_head *tmp = *hp; |
| 86 | if (detail->match(tmp, key)) { |
| 87 | cache_get(tmp); |
| 88 | write_unlock(&detail->hash_lock); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 89 | cache_put(new, detail); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 90 | return tmp; |
| 91 | } |
| 92 | } |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 93 | new->next = *head; |
| 94 | *head = new; |
| 95 | detail->entries++; |
| 96 | cache_get(new); |
| 97 | write_unlock(&detail->hash_lock); |
| 98 | |
| 99 | return new; |
| 100 | } |
| 101 | EXPORT_SYMBOL(sunrpc_cache_lookup); |
| 102 | |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 103 | |
| 104 | static void queue_loose(struct cache_detail *detail, struct cache_head *ch); |
| 105 | |
| 106 | static int cache_fresh_locked(struct cache_head *head, time_t expiry) |
| 107 | { |
| 108 | head->expiry_time = expiry; |
| 109 | head->last_refresh = get_seconds(); |
| 110 | return !test_and_set_bit(CACHE_VALID, &head->flags); |
| 111 | } |
| 112 | |
| 113 | static void cache_fresh_unlocked(struct cache_head *head, |
| 114 | struct cache_detail *detail, int new) |
| 115 | { |
| 116 | if (new) |
| 117 | cache_revisit_request(head); |
| 118 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { |
| 119 | cache_revisit_request(head); |
| 120 | queue_loose(detail, head); |
| 121 | } |
| 122 | } |
| 123 | |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 124 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, |
| 125 | struct cache_head *new, struct cache_head *old, int hash) |
| 126 | { |
| 127 | /* The 'old' entry is to be replaced by 'new'. |
| 128 | * If 'old' is not VALID, we update it directly, |
| 129 | * otherwise we need to replace it |
| 130 | */ |
| 131 | struct cache_head **head; |
| 132 | struct cache_head *tmp; |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 133 | int is_new; |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 134 | |
| 135 | if (!test_bit(CACHE_VALID, &old->flags)) { |
| 136 | write_lock(&detail->hash_lock); |
| 137 | if (!test_bit(CACHE_VALID, &old->flags)) { |
| 138 | if (test_bit(CACHE_NEGATIVE, &new->flags)) |
| 139 | set_bit(CACHE_NEGATIVE, &old->flags); |
| 140 | else |
| 141 | detail->update(old, new); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 142 | is_new = cache_fresh_locked(old, new->expiry_time); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 143 | write_unlock(&detail->hash_lock); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 144 | cache_fresh_unlocked(old, detail, is_new); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 145 | return old; |
| 146 | } |
| 147 | write_unlock(&detail->hash_lock); |
| 148 | } |
| 149 | /* We need to insert a new entry */ |
| 150 | tmp = detail->alloc(); |
| 151 | if (!tmp) { |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 152 | cache_put(old, detail); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 153 | return NULL; |
| 154 | } |
| 155 | cache_init(tmp); |
| 156 | detail->init(tmp, old); |
| 157 | head = &detail->hash_table[hash]; |
| 158 | |
| 159 | write_lock(&detail->hash_lock); |
| 160 | if (test_bit(CACHE_NEGATIVE, &new->flags)) |
| 161 | set_bit(CACHE_NEGATIVE, &tmp->flags); |
| 162 | else |
| 163 | detail->update(tmp, new); |
| 164 | tmp->next = *head; |
| 165 | *head = tmp; |
NeilBrown | f2d3958 | 2006-05-22 22:35:25 -0700 | [diff] [blame] | 166 | detail->entries++; |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 167 | cache_get(tmp); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 168 | is_new = cache_fresh_locked(tmp, new->expiry_time); |
| 169 | cache_fresh_locked(old, 0); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 170 | write_unlock(&detail->hash_lock); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 171 | cache_fresh_unlocked(tmp, detail, is_new); |
| 172 | cache_fresh_unlocked(old, detail, 0); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 173 | cache_put(old, detail); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 174 | return tmp; |
| 175 | } |
| 176 | EXPORT_SYMBOL(sunrpc_cache_update); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | |
| 178 | static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h); |
| 179 | /* |
| 180 | * This is the generic cache management routine for all |
| 181 | * the authentication caches. |
| 182 | * It checks the currency of a cache item and will (later) |
| 183 | * initiate an upcall to fill it if needed. |
| 184 | * |
| 185 | * |
| 186 | * Returns 0 if the cache_head can be used, or cache_puts it and returns |
| 187 | * -EAGAIN if upcall is pending, |
J.Bruce Fields | e0bb89e | 2006-12-13 00:35:25 -0800 | [diff] [blame] | 188 | * -ETIMEDOUT if upcall failed and should be retried, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | * -ENOENT if cache entry was negative |
| 190 | */ |
| 191 | int cache_check(struct cache_detail *detail, |
| 192 | struct cache_head *h, struct cache_req *rqstp) |
| 193 | { |
| 194 | int rv; |
| 195 | long refresh_age, age; |
| 196 | |
| 197 | /* First decide return status as best we can */ |
| 198 | if (!test_bit(CACHE_VALID, &h->flags) || |
| 199 | h->expiry_time < get_seconds()) |
| 200 | rv = -EAGAIN; |
| 201 | else if (detail->flush_time > h->last_refresh) |
| 202 | rv = -EAGAIN; |
| 203 | else { |
| 204 | /* entry is valid */ |
| 205 | if (test_bit(CACHE_NEGATIVE, &h->flags)) |
| 206 | rv = -ENOENT; |
| 207 | else rv = 0; |
| 208 | } |
| 209 | |
| 210 | /* now see if we want to start an upcall */ |
| 211 | refresh_age = (h->expiry_time - h->last_refresh); |
| 212 | age = get_seconds() - h->last_refresh; |
| 213 | |
| 214 | if (rqstp == NULL) { |
| 215 | if (rv == -EAGAIN) |
| 216 | rv = -ENOENT; |
| 217 | } else if (rv == -EAGAIN || age > refresh_age/2) { |
Chuck Lever | 46121cf | 2007-01-31 12:14:08 -0500 | [diff] [blame] | 218 | dprintk("RPC: Want update, refage=%ld, age=%ld\n", |
| 219 | refresh_age, age); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { |
| 221 | switch (cache_make_upcall(detail, h)) { |
| 222 | case -EINVAL: |
| 223 | clear_bit(CACHE_PENDING, &h->flags); |
| 224 | if (rv == -EAGAIN) { |
| 225 | set_bit(CACHE_NEGATIVE, &h->flags); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 226 | cache_fresh_unlocked(h, detail, |
| 227 | cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | rv = -ENOENT; |
| 229 | } |
| 230 | break; |
| 231 | |
| 232 | case -EAGAIN: |
| 233 | clear_bit(CACHE_PENDING, &h->flags); |
| 234 | cache_revisit_request(h); |
| 235 | break; |
| 236 | } |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | if (rv == -EAGAIN) |
J.Bruce Fields | e0bb89e | 2006-12-13 00:35:25 -0800 | [diff] [blame] | 241 | if (cache_defer_req(rqstp, h) != 0) |
| 242 | rv = -ETIMEDOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 244 | if (rv) |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 245 | cache_put(h, detail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | return rv; |
| 247 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 248 | EXPORT_SYMBOL(cache_check); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | /* |
| 251 | * caches need to be periodically cleaned. |
| 252 | * For this we maintain a list of cache_detail and |
| 253 | * a current pointer into that list and into the table |
| 254 | * for that entry. |
| 255 | * |
| 256 | * Each time clean_cache is called it finds the next non-empty entry |
| 257 | * in the current table and walks the list in that entry |
| 258 | * looking for entries that can be removed. |
| 259 | * |
| 260 | * An entry gets removed if: |
| 261 | * - The expiry is before current time |
| 262 | * - The last_refresh time is before the flush_time for that cache |
| 263 | * |
| 264 | * later we might drop old entries with non-NEVER expiry if that table |
| 265 | * is getting 'full' for some definition of 'full' |
| 266 | * |
| 267 | * The question of "how often to scan a table" is an interesting one |
| 268 | * and is answered in part by the use of the "nextcheck" field in the |
| 269 | * cache_detail. |
| 270 | * When a scan of a table begins, the nextcheck field is set to a time |
| 271 | * that is well into the future. |
| 272 | * While scanning, if an expiry time is found that is earlier than the |
| 273 | * current nextcheck time, nextcheck is set to that expiry time. |
| 274 | * If the flush_time is ever set to a time earlier than the nextcheck |
| 275 | * time, the nextcheck time is then set to that flush_time. |
| 276 | * |
| 277 | * A table is then only scanned if the current time is at least |
| 278 | * the nextcheck time. |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 279 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | */ |
| 281 | |
| 282 | static LIST_HEAD(cache_list); |
| 283 | static DEFINE_SPINLOCK(cache_list_lock); |
| 284 | static struct cache_detail *current_detail; |
| 285 | static int current_index; |
| 286 | |
Arjan van de Ven | da7071d | 2007-02-12 00:55:36 -0800 | [diff] [blame] | 287 | static const struct file_operations cache_file_operations; |
| 288 | static const struct file_operations content_file_operations; |
| 289 | static const struct file_operations cache_flush_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 291 | static void do_cache_clean(struct work_struct *work); |
| 292 | static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 294 | static void remove_cache_proc_entries(struct cache_detail *cd) |
| 295 | { |
| 296 | if (cd->proc_ent == NULL) |
| 297 | return; |
| 298 | if (cd->flush_ent) |
| 299 | remove_proc_entry("flush", cd->proc_ent); |
| 300 | if (cd->channel_ent) |
| 301 | remove_proc_entry("channel", cd->proc_ent); |
| 302 | if (cd->content_ent) |
| 303 | remove_proc_entry("content", cd->proc_ent); |
| 304 | cd->proc_ent = NULL; |
| 305 | remove_proc_entry(cd->name, proc_net_rpc); |
| 306 | } |
| 307 | |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 308 | #ifdef CONFIG_PROC_FS |
| 309 | static int create_cache_proc_entries(struct cache_detail *cd) |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 310 | { |
| 311 | struct proc_dir_entry *p; |
| 312 | |
| 313 | cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc); |
| 314 | if (cd->proc_ent == NULL) |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 315 | goto out_nomem; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 316 | cd->proc_ent->owner = cd->owner; |
| 317 | cd->channel_ent = cd->content_ent = NULL; |
| 318 | |
Denis V. Lunev | e7fe233 | 2008-05-02 02:44:36 -0700 | [diff] [blame^] | 319 | p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, |
| 320 | cd->proc_ent, &cache_flush_operations, cd); |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 321 | cd->flush_ent = p; |
| 322 | if (p == NULL) |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 323 | goto out_nomem; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 324 | p->owner = cd->owner; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 325 | |
| 326 | if (cd->cache_request || cd->cache_parse) { |
Denis V. Lunev | e7fe233 | 2008-05-02 02:44:36 -0700 | [diff] [blame^] | 327 | p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, |
| 328 | cd->proc_ent, &cache_file_operations, cd); |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 329 | cd->channel_ent = p; |
| 330 | if (p == NULL) |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 331 | goto out_nomem; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 332 | p->owner = cd->owner; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 333 | } |
| 334 | if (cd->cache_show) { |
Denis V. Lunev | e7fe233 | 2008-05-02 02:44:36 -0700 | [diff] [blame^] | 335 | p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, |
| 336 | cd->proc_ent, &content_file_operations, cd); |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 337 | cd->content_ent = p; |
| 338 | if (p == NULL) |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 339 | goto out_nomem; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 340 | p->owner = cd->owner; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 341 | } |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 342 | return 0; |
| 343 | out_nomem: |
| 344 | remove_cache_proc_entries(cd); |
| 345 | return -ENOMEM; |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 346 | } |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 347 | #else /* CONFIG_PROC_FS */ |
| 348 | static int create_cache_proc_entries(struct cache_detail *cd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | { |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 350 | return 0; |
| 351 | } |
| 352 | #endif |
| 353 | |
| 354 | int cache_register(struct cache_detail *cd) |
| 355 | { |
| 356 | int ret; |
| 357 | |
| 358 | ret = create_cache_proc_entries(cd); |
| 359 | if (ret) |
| 360 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | rwlock_init(&cd->hash_lock); |
| 362 | INIT_LIST_HEAD(&cd->queue); |
| 363 | spin_lock(&cache_list_lock); |
| 364 | cd->nextcheck = 0; |
| 365 | cd->entries = 0; |
| 366 | atomic_set(&cd->readers, 0); |
| 367 | cd->last_close = 0; |
| 368 | cd->last_warn = -1; |
| 369 | list_add(&cd->others, &cache_list); |
| 370 | spin_unlock(&cache_list_lock); |
| 371 | |
| 372 | /* start the cleaning process */ |
David Howells | 52bad64 | 2006-11-22 14:54:01 +0000 | [diff] [blame] | 373 | schedule_delayed_work(&cache_cleaner, 0); |
J. Bruce Fields | dbf847e | 2007-11-08 17:20:34 -0500 | [diff] [blame] | 374 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 376 | EXPORT_SYMBOL(cache_register); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | |
J. Bruce Fields | df95a9d | 2007-11-08 16:09:59 -0500 | [diff] [blame] | 378 | void cache_unregister(struct cache_detail *cd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | { |
| 380 | cache_purge(cd); |
| 381 | spin_lock(&cache_list_lock); |
| 382 | write_lock(&cd->hash_lock); |
| 383 | if (cd->entries || atomic_read(&cd->inuse)) { |
| 384 | write_unlock(&cd->hash_lock); |
| 385 | spin_unlock(&cache_list_lock); |
J. Bruce Fields | df95a9d | 2007-11-08 16:09:59 -0500 | [diff] [blame] | 386 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | } |
| 388 | if (current_detail == cd) |
| 389 | current_detail = NULL; |
| 390 | list_del_init(&cd->others); |
| 391 | write_unlock(&cd->hash_lock); |
| 392 | spin_unlock(&cache_list_lock); |
J. Bruce Fields | ffe9386 | 2007-11-12 17:04:29 -0500 | [diff] [blame] | 393 | remove_cache_proc_entries(cd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | if (list_empty(&cache_list)) { |
| 395 | /* module must be being unloaded so its safe to kill the worker */ |
Trond Myklebust | 4011cd9 | 2007-08-07 15:33:01 -0400 | [diff] [blame] | 396 | cancel_delayed_work_sync(&cache_cleaner); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | } |
J. Bruce Fields | df95a9d | 2007-11-08 16:09:59 -0500 | [diff] [blame] | 398 | return; |
| 399 | out: |
| 400 | printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 402 | EXPORT_SYMBOL(cache_unregister); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | |
| 404 | /* clean cache tries to find something to clean |
| 405 | * and cleans it. |
| 406 | * It returns 1 if it cleaned something, |
| 407 | * 0 if it didn't find anything this time |
| 408 | * -1 if it fell off the end of the list. |
| 409 | */ |
| 410 | static int cache_clean(void) |
| 411 | { |
| 412 | int rv = 0; |
| 413 | struct list_head *next; |
| 414 | |
| 415 | spin_lock(&cache_list_lock); |
| 416 | |
| 417 | /* find a suitable table if we don't already have one */ |
| 418 | while (current_detail == NULL || |
| 419 | current_index >= current_detail->hash_size) { |
| 420 | if (current_detail) |
| 421 | next = current_detail->others.next; |
| 422 | else |
| 423 | next = cache_list.next; |
| 424 | if (next == &cache_list) { |
| 425 | current_detail = NULL; |
| 426 | spin_unlock(&cache_list_lock); |
| 427 | return -1; |
| 428 | } |
| 429 | current_detail = list_entry(next, struct cache_detail, others); |
| 430 | if (current_detail->nextcheck > get_seconds()) |
| 431 | current_index = current_detail->hash_size; |
| 432 | else { |
| 433 | current_index = 0; |
| 434 | current_detail->nextcheck = get_seconds()+30*60; |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | /* find a non-empty bucket in the table */ |
| 439 | while (current_detail && |
| 440 | current_index < current_detail->hash_size && |
| 441 | current_detail->hash_table[current_index] == NULL) |
| 442 | current_index++; |
| 443 | |
| 444 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 445 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | if (current_detail && current_index < current_detail->hash_size) { |
| 447 | struct cache_head *ch, **cp; |
| 448 | struct cache_detail *d; |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | write_lock(¤t_detail->hash_lock); |
| 451 | |
| 452 | /* Ok, now to clean this strand */ |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 453 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | cp = & current_detail->hash_table[current_index]; |
| 455 | ch = *cp; |
| 456 | for (; ch; cp= & ch->next, ch= *cp) { |
| 457 | if (current_detail->nextcheck > ch->expiry_time) |
| 458 | current_detail->nextcheck = ch->expiry_time+1; |
| 459 | if (ch->expiry_time >= get_seconds() |
| 460 | && ch->last_refresh >= current_detail->flush_time |
| 461 | ) |
| 462 | continue; |
| 463 | if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) |
| 464 | queue_loose(current_detail, ch); |
| 465 | |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 466 | if (atomic_read(&ch->ref.refcount) == 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | break; |
| 468 | } |
| 469 | if (ch) { |
| 470 | *cp = ch->next; |
| 471 | ch->next = NULL; |
| 472 | current_detail->entries--; |
| 473 | rv = 1; |
| 474 | } |
| 475 | write_unlock(¤t_detail->hash_lock); |
| 476 | d = current_detail; |
| 477 | if (!ch) |
| 478 | current_index ++; |
| 479 | spin_unlock(&cache_list_lock); |
| 480 | if (ch) |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 481 | cache_put(ch, d); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | } else |
| 483 | spin_unlock(&cache_list_lock); |
| 484 | |
| 485 | return rv; |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * We want to regularly clean the cache, so we need to schedule some work ... |
| 490 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 491 | static void do_cache_clean(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | { |
| 493 | int delay = 5; |
| 494 | if (cache_clean() == -1) |
| 495 | delay = 30*HZ; |
| 496 | |
| 497 | if (list_empty(&cache_list)) |
| 498 | delay = 0; |
| 499 | |
| 500 | if (delay) |
| 501 | schedule_delayed_work(&cache_cleaner, delay); |
| 502 | } |
| 503 | |
| 504 | |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 505 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | * Clean all caches promptly. This just calls cache_clean |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 507 | * repeatedly until we are sure that every cache has had a chance to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | * be fully cleaned |
| 509 | */ |
| 510 | void cache_flush(void) |
| 511 | { |
| 512 | while (cache_clean() != -1) |
| 513 | cond_resched(); |
| 514 | while (cache_clean() != -1) |
| 515 | cond_resched(); |
| 516 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 517 | EXPORT_SYMBOL(cache_flush); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | |
| 519 | void cache_purge(struct cache_detail *detail) |
| 520 | { |
| 521 | detail->flush_time = LONG_MAX; |
| 522 | detail->nextcheck = get_seconds(); |
| 523 | cache_flush(); |
| 524 | detail->flush_time = 1; |
| 525 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 526 | EXPORT_SYMBOL(cache_purge); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | |
| 528 | |
| 529 | /* |
| 530 | * Deferral and Revisiting of Requests. |
| 531 | * |
| 532 | * If a cache lookup finds a pending entry, we |
| 533 | * need to defer the request and revisit it later. |
| 534 | * All deferred requests are stored in a hash table, |
| 535 | * indexed by "struct cache_head *". |
| 536 | * As it may be wasteful to store a whole request |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 537 | * structure, we allow the request to provide a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | * deferred form, which must contain a |
| 539 | * 'struct cache_deferred_req' |
| 540 | * This cache_deferred_req contains a method to allow |
| 541 | * it to be revisited when cache info is available |
| 542 | */ |
| 543 | |
| 544 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) |
| 545 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) |
| 546 | |
| 547 | #define DFR_MAX 300 /* ??? */ |
| 548 | |
| 549 | static DEFINE_SPINLOCK(cache_defer_lock); |
| 550 | static LIST_HEAD(cache_defer_list); |
| 551 | static struct list_head cache_defer_hash[DFR_HASHSIZE]; |
| 552 | static int cache_defer_cnt; |
| 553 | |
J.Bruce Fields | e0bb89e | 2006-12-13 00:35:25 -0800 | [diff] [blame] | 554 | static int cache_defer_req(struct cache_req *req, struct cache_head *item) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | { |
| 556 | struct cache_deferred_req *dreq; |
| 557 | int hash = DFR_HASH(item); |
| 558 | |
J.Bruce Fields | 01f3bd1 | 2006-12-13 00:35:26 -0800 | [diff] [blame] | 559 | if (cache_defer_cnt >= DFR_MAX) { |
| 560 | /* too much in the cache, randomly drop this one, |
| 561 | * or continue and drop the oldest below |
| 562 | */ |
| 563 | if (net_random()&1) |
| 564 | return -ETIMEDOUT; |
| 565 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | dreq = req->defer(req); |
| 567 | if (dreq == NULL) |
J.Bruce Fields | e0bb89e | 2006-12-13 00:35:25 -0800 | [diff] [blame] | 568 | return -ETIMEDOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | |
| 570 | dreq->item = item; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | |
| 572 | spin_lock(&cache_defer_lock); |
| 573 | |
| 574 | list_add(&dreq->recent, &cache_defer_list); |
| 575 | |
| 576 | if (cache_defer_hash[hash].next == NULL) |
| 577 | INIT_LIST_HEAD(&cache_defer_hash[hash]); |
| 578 | list_add(&dreq->hash, &cache_defer_hash[hash]); |
| 579 | |
| 580 | /* it is in, now maybe clean up */ |
| 581 | dreq = NULL; |
| 582 | if (++cache_defer_cnt > DFR_MAX) { |
J.Bruce Fields | 01f3bd1 | 2006-12-13 00:35:26 -0800 | [diff] [blame] | 583 | dreq = list_entry(cache_defer_list.prev, |
| 584 | struct cache_deferred_req, recent); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | list_del(&dreq->recent); |
| 586 | list_del(&dreq->hash); |
| 587 | cache_defer_cnt--; |
| 588 | } |
| 589 | spin_unlock(&cache_defer_lock); |
| 590 | |
| 591 | if (dreq) { |
| 592 | /* there was one too many */ |
| 593 | dreq->revisit(dreq, 1); |
| 594 | } |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 595 | if (!test_bit(CACHE_PENDING, &item->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | /* must have just been validated... */ |
| 597 | cache_revisit_request(item); |
| 598 | } |
J.Bruce Fields | e0bb89e | 2006-12-13 00:35:25 -0800 | [diff] [blame] | 599 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | } |
| 601 | |
| 602 | static void cache_revisit_request(struct cache_head *item) |
| 603 | { |
| 604 | struct cache_deferred_req *dreq; |
| 605 | struct list_head pending; |
| 606 | |
| 607 | struct list_head *lp; |
| 608 | int hash = DFR_HASH(item); |
| 609 | |
| 610 | INIT_LIST_HEAD(&pending); |
| 611 | spin_lock(&cache_defer_lock); |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 612 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | lp = cache_defer_hash[hash].next; |
| 614 | if (lp) { |
| 615 | while (lp != &cache_defer_hash[hash]) { |
| 616 | dreq = list_entry(lp, struct cache_deferred_req, hash); |
| 617 | lp = lp->next; |
| 618 | if (dreq->item == item) { |
| 619 | list_del(&dreq->hash); |
| 620 | list_move(&dreq->recent, &pending); |
| 621 | cache_defer_cnt--; |
| 622 | } |
| 623 | } |
| 624 | } |
| 625 | spin_unlock(&cache_defer_lock); |
| 626 | |
| 627 | while (!list_empty(&pending)) { |
| 628 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); |
| 629 | list_del_init(&dreq->recent); |
| 630 | dreq->revisit(dreq, 0); |
| 631 | } |
| 632 | } |
| 633 | |
| 634 | void cache_clean_deferred(void *owner) |
| 635 | { |
| 636 | struct cache_deferred_req *dreq, *tmp; |
| 637 | struct list_head pending; |
| 638 | |
| 639 | |
| 640 | INIT_LIST_HEAD(&pending); |
| 641 | spin_lock(&cache_defer_lock); |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 642 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { |
| 644 | if (dreq->owner == owner) { |
| 645 | list_del(&dreq->hash); |
| 646 | list_move(&dreq->recent, &pending); |
| 647 | cache_defer_cnt--; |
| 648 | } |
| 649 | } |
| 650 | spin_unlock(&cache_defer_lock); |
| 651 | |
| 652 | while (!list_empty(&pending)) { |
| 653 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); |
| 654 | list_del_init(&dreq->recent); |
| 655 | dreq->revisit(dreq, 1); |
| 656 | } |
| 657 | } |
| 658 | |
| 659 | /* |
| 660 | * communicate with user-space |
| 661 | * |
J. Bruce Fields | a490c68 | 2007-11-06 14:15:19 -0500 | [diff] [blame] | 662 | * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. |
| 663 | * On read, you get a full request, or block. |
| 664 | * On write, an update request is processed. |
| 665 | * Poll works if anything to read, and always allows write. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | * |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 667 | * Implemented by linked list of requests. Each open file has |
J. Bruce Fields | a490c68 | 2007-11-06 14:15:19 -0500 | [diff] [blame] | 668 | * a ->private that also exists in this list. New requests are added |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | * to the end and may wakeup and preceding readers. |
| 670 | * New readers are added to the head. If, on read, an item is found with |
| 671 | * CACHE_UPCALLING clear, we free it from the list. |
| 672 | * |
| 673 | */ |
| 674 | |
| 675 | static DEFINE_SPINLOCK(queue_lock); |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 676 | static DEFINE_MUTEX(queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | |
| 678 | struct cache_queue { |
| 679 | struct list_head list; |
| 680 | int reader; /* if 0, then request */ |
| 681 | }; |
| 682 | struct cache_request { |
| 683 | struct cache_queue q; |
| 684 | struct cache_head *item; |
| 685 | char * buf; |
| 686 | int len; |
| 687 | int readers; |
| 688 | }; |
| 689 | struct cache_reader { |
| 690 | struct cache_queue q; |
| 691 | int offset; /* if non-0, we have a refcnt on next request */ |
| 692 | }; |
| 693 | |
| 694 | static ssize_t |
| 695 | cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) |
| 696 | { |
| 697 | struct cache_reader *rp = filp->private_data; |
| 698 | struct cache_request *rq; |
Josef Sipek | 303b46b | 2006-12-08 02:37:42 -0800 | [diff] [blame] | 699 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | int err; |
| 701 | |
| 702 | if (count == 0) |
| 703 | return 0; |
| 704 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 705 | mutex_lock(&queue_io_mutex); /* protect against multiple concurrent |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | * readers on this file */ |
| 707 | again: |
| 708 | spin_lock(&queue_lock); |
| 709 | /* need to find next request */ |
| 710 | while (rp->q.list.next != &cd->queue && |
| 711 | list_entry(rp->q.list.next, struct cache_queue, list) |
| 712 | ->reader) { |
| 713 | struct list_head *next = rp->q.list.next; |
| 714 | list_move(&rp->q.list, next); |
| 715 | } |
| 716 | if (rp->q.list.next == &cd->queue) { |
| 717 | spin_unlock(&queue_lock); |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 718 | mutex_unlock(&queue_io_mutex); |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 719 | BUG_ON(rp->offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | return 0; |
| 721 | } |
| 722 | rq = container_of(rp->q.list.next, struct cache_request, q.list); |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 723 | BUG_ON(rq->q.reader); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | if (rp->offset == 0) |
| 725 | rq->readers++; |
| 726 | spin_unlock(&queue_lock); |
| 727 | |
| 728 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { |
| 729 | err = -EAGAIN; |
| 730 | spin_lock(&queue_lock); |
| 731 | list_move(&rp->q.list, &rq->q.list); |
| 732 | spin_unlock(&queue_lock); |
| 733 | } else { |
| 734 | if (rp->offset + count > rq->len) |
| 735 | count = rq->len - rp->offset; |
| 736 | err = -EFAULT; |
| 737 | if (copy_to_user(buf, rq->buf + rp->offset, count)) |
| 738 | goto out; |
| 739 | rp->offset += count; |
| 740 | if (rp->offset >= rq->len) { |
| 741 | rp->offset = 0; |
| 742 | spin_lock(&queue_lock); |
| 743 | list_move(&rp->q.list, &rq->q.list); |
| 744 | spin_unlock(&queue_lock); |
| 745 | } |
| 746 | err = 0; |
| 747 | } |
| 748 | out: |
| 749 | if (rp->offset == 0) { |
| 750 | /* need to release rq */ |
| 751 | spin_lock(&queue_lock); |
| 752 | rq->readers--; |
| 753 | if (rq->readers == 0 && |
| 754 | !test_bit(CACHE_PENDING, &rq->item->flags)) { |
| 755 | list_del(&rq->q.list); |
| 756 | spin_unlock(&queue_lock); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 757 | cache_put(rq->item, cd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | kfree(rq->buf); |
| 759 | kfree(rq); |
| 760 | } else |
| 761 | spin_unlock(&queue_lock); |
| 762 | } |
| 763 | if (err == -EAGAIN) |
| 764 | goto again; |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 765 | mutex_unlock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | return err ? err : count; |
| 767 | } |
| 768 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 769 | static char write_buf[8192]; /* protected by queue_io_mutex */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | |
| 771 | static ssize_t |
| 772 | cache_write(struct file *filp, const char __user *buf, size_t count, |
| 773 | loff_t *ppos) |
| 774 | { |
| 775 | int err; |
Josef Sipek | 303b46b | 2006-12-08 02:37:42 -0800 | [diff] [blame] | 776 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | |
| 778 | if (count == 0) |
| 779 | return 0; |
| 780 | if (count >= sizeof(write_buf)) |
| 781 | return -EINVAL; |
| 782 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 783 | mutex_lock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | |
| 785 | if (copy_from_user(write_buf, buf, count)) { |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 786 | mutex_unlock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | return -EFAULT; |
| 788 | } |
| 789 | write_buf[count] = '\0'; |
| 790 | if (cd->cache_parse) |
| 791 | err = cd->cache_parse(cd, write_buf, count); |
| 792 | else |
| 793 | err = -EINVAL; |
| 794 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 795 | mutex_unlock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | return err ? err : count; |
| 797 | } |
| 798 | |
| 799 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); |
| 800 | |
| 801 | static unsigned int |
| 802 | cache_poll(struct file *filp, poll_table *wait) |
| 803 | { |
| 804 | unsigned int mask; |
| 805 | struct cache_reader *rp = filp->private_data; |
| 806 | struct cache_queue *cq; |
Josef Sipek | 303b46b | 2006-12-08 02:37:42 -0800 | [diff] [blame] | 807 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | |
| 809 | poll_wait(filp, &queue_wait, wait); |
| 810 | |
| 811 | /* alway allow write */ |
| 812 | mask = POLL_OUT | POLLWRNORM; |
| 813 | |
| 814 | if (!rp) |
| 815 | return mask; |
| 816 | |
| 817 | spin_lock(&queue_lock); |
| 818 | |
| 819 | for (cq= &rp->q; &cq->list != &cd->queue; |
| 820 | cq = list_entry(cq->list.next, struct cache_queue, list)) |
| 821 | if (!cq->reader) { |
| 822 | mask |= POLLIN | POLLRDNORM; |
| 823 | break; |
| 824 | } |
| 825 | spin_unlock(&queue_lock); |
| 826 | return mask; |
| 827 | } |
| 828 | |
| 829 | static int |
| 830 | cache_ioctl(struct inode *ino, struct file *filp, |
| 831 | unsigned int cmd, unsigned long arg) |
| 832 | { |
| 833 | int len = 0; |
| 834 | struct cache_reader *rp = filp->private_data; |
| 835 | struct cache_queue *cq; |
| 836 | struct cache_detail *cd = PDE(ino)->data; |
| 837 | |
| 838 | if (cmd != FIONREAD || !rp) |
| 839 | return -EINVAL; |
| 840 | |
| 841 | spin_lock(&queue_lock); |
| 842 | |
| 843 | /* only find the length remaining in current request, |
| 844 | * or the length of the next request |
| 845 | */ |
| 846 | for (cq= &rp->q; &cq->list != &cd->queue; |
| 847 | cq = list_entry(cq->list.next, struct cache_queue, list)) |
| 848 | if (!cq->reader) { |
| 849 | struct cache_request *cr = |
| 850 | container_of(cq, struct cache_request, q); |
| 851 | len = cr->len - rp->offset; |
| 852 | break; |
| 853 | } |
| 854 | spin_unlock(&queue_lock); |
| 855 | |
| 856 | return put_user(len, (int __user *)arg); |
| 857 | } |
| 858 | |
| 859 | static int |
| 860 | cache_open(struct inode *inode, struct file *filp) |
| 861 | { |
| 862 | struct cache_reader *rp = NULL; |
| 863 | |
| 864 | nonseekable_open(inode, filp); |
| 865 | if (filp->f_mode & FMODE_READ) { |
| 866 | struct cache_detail *cd = PDE(inode)->data; |
| 867 | |
| 868 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); |
| 869 | if (!rp) |
| 870 | return -ENOMEM; |
| 871 | rp->offset = 0; |
| 872 | rp->q.reader = 1; |
| 873 | atomic_inc(&cd->readers); |
| 874 | spin_lock(&queue_lock); |
| 875 | list_add(&rp->q.list, &cd->queue); |
| 876 | spin_unlock(&queue_lock); |
| 877 | } |
| 878 | filp->private_data = rp; |
| 879 | return 0; |
| 880 | } |
| 881 | |
| 882 | static int |
| 883 | cache_release(struct inode *inode, struct file *filp) |
| 884 | { |
| 885 | struct cache_reader *rp = filp->private_data; |
| 886 | struct cache_detail *cd = PDE(inode)->data; |
| 887 | |
| 888 | if (rp) { |
| 889 | spin_lock(&queue_lock); |
| 890 | if (rp->offset) { |
| 891 | struct cache_queue *cq; |
| 892 | for (cq= &rp->q; &cq->list != &cd->queue; |
| 893 | cq = list_entry(cq->list.next, struct cache_queue, list)) |
| 894 | if (!cq->reader) { |
| 895 | container_of(cq, struct cache_request, q) |
| 896 | ->readers--; |
| 897 | break; |
| 898 | } |
| 899 | rp->offset = 0; |
| 900 | } |
| 901 | list_del(&rp->q.list); |
| 902 | spin_unlock(&queue_lock); |
| 903 | |
| 904 | filp->private_data = NULL; |
| 905 | kfree(rp); |
| 906 | |
| 907 | cd->last_close = get_seconds(); |
| 908 | atomic_dec(&cd->readers); |
| 909 | } |
| 910 | return 0; |
| 911 | } |
| 912 | |
| 913 | |
| 914 | |
Arjan van de Ven | da7071d | 2007-02-12 00:55:36 -0800 | [diff] [blame] | 915 | static const struct file_operations cache_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | .owner = THIS_MODULE, |
| 917 | .llseek = no_llseek, |
| 918 | .read = cache_read, |
| 919 | .write = cache_write, |
| 920 | .poll = cache_poll, |
| 921 | .ioctl = cache_ioctl, /* for FIONREAD */ |
| 922 | .open = cache_open, |
| 923 | .release = cache_release, |
| 924 | }; |
| 925 | |
| 926 | |
| 927 | static void queue_loose(struct cache_detail *detail, struct cache_head *ch) |
| 928 | { |
| 929 | struct cache_queue *cq; |
| 930 | spin_lock(&queue_lock); |
| 931 | list_for_each_entry(cq, &detail->queue, list) |
| 932 | if (!cq->reader) { |
| 933 | struct cache_request *cr = container_of(cq, struct cache_request, q); |
| 934 | if (cr->item != ch) |
| 935 | continue; |
| 936 | if (cr->readers != 0) |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 937 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | list_del(&cr->q.list); |
| 939 | spin_unlock(&queue_lock); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 940 | cache_put(cr->item, detail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | kfree(cr->buf); |
| 942 | kfree(cr); |
| 943 | return; |
| 944 | } |
| 945 | spin_unlock(&queue_lock); |
| 946 | } |
| 947 | |
| 948 | /* |
| 949 | * Support routines for text-based upcalls. |
| 950 | * Fields are separated by spaces. |
| 951 | * Fields are either mangled to quote space tab newline slosh with slosh |
| 952 | * or a hexified with a leading \x |
| 953 | * Record is terminated with newline. |
| 954 | * |
| 955 | */ |
| 956 | |
| 957 | void qword_add(char **bpp, int *lp, char *str) |
| 958 | { |
| 959 | char *bp = *bpp; |
| 960 | int len = *lp; |
| 961 | char c; |
| 962 | |
| 963 | if (len < 0) return; |
| 964 | |
| 965 | while ((c=*str++) && len) |
| 966 | switch(c) { |
| 967 | case ' ': |
| 968 | case '\t': |
| 969 | case '\n': |
| 970 | case '\\': |
| 971 | if (len >= 4) { |
| 972 | *bp++ = '\\'; |
| 973 | *bp++ = '0' + ((c & 0300)>>6); |
| 974 | *bp++ = '0' + ((c & 0070)>>3); |
| 975 | *bp++ = '0' + ((c & 0007)>>0); |
| 976 | } |
| 977 | len -= 4; |
| 978 | break; |
| 979 | default: |
| 980 | *bp++ = c; |
| 981 | len--; |
| 982 | } |
| 983 | if (c || len <1) len = -1; |
| 984 | else { |
| 985 | *bp++ = ' '; |
| 986 | len--; |
| 987 | } |
| 988 | *bpp = bp; |
| 989 | *lp = len; |
| 990 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 991 | EXPORT_SYMBOL(qword_add); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | |
| 993 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) |
| 994 | { |
| 995 | char *bp = *bpp; |
| 996 | int len = *lp; |
| 997 | |
| 998 | if (len < 0) return; |
| 999 | |
| 1000 | if (len > 2) { |
| 1001 | *bp++ = '\\'; |
| 1002 | *bp++ = 'x'; |
| 1003 | len -= 2; |
| 1004 | while (blen && len >= 2) { |
| 1005 | unsigned char c = *buf++; |
| 1006 | *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); |
| 1007 | *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); |
| 1008 | len -= 2; |
| 1009 | blen--; |
| 1010 | } |
| 1011 | } |
| 1012 | if (blen || len<1) len = -1; |
| 1013 | else { |
| 1014 | *bp++ = ' '; |
| 1015 | len--; |
| 1016 | } |
| 1017 | *bpp = bp; |
| 1018 | *lp = len; |
| 1019 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 1020 | EXPORT_SYMBOL(qword_addhex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | |
| 1022 | static void warn_no_listener(struct cache_detail *detail) |
| 1023 | { |
| 1024 | if (detail->last_warn != detail->last_close) { |
| 1025 | detail->last_warn = detail->last_close; |
| 1026 | if (detail->warn_no_listener) |
| 1027 | detail->warn_no_listener(detail); |
| 1028 | } |
| 1029 | } |
| 1030 | |
| 1031 | /* |
| 1032 | * register an upcall request to user-space. |
| 1033 | * Each request is at most one page long. |
| 1034 | */ |
| 1035 | static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h) |
| 1036 | { |
| 1037 | |
| 1038 | char *buf; |
| 1039 | struct cache_request *crq; |
| 1040 | char *bp; |
| 1041 | int len; |
| 1042 | |
| 1043 | if (detail->cache_request == NULL) |
| 1044 | return -EINVAL; |
| 1045 | |
| 1046 | if (atomic_read(&detail->readers) == 0 && |
| 1047 | detail->last_close < get_seconds() - 30) { |
| 1048 | warn_no_listener(detail); |
| 1049 | return -EINVAL; |
| 1050 | } |
| 1051 | |
| 1052 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
| 1053 | if (!buf) |
| 1054 | return -EAGAIN; |
| 1055 | |
| 1056 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); |
| 1057 | if (!crq) { |
| 1058 | kfree(buf); |
| 1059 | return -EAGAIN; |
| 1060 | } |
| 1061 | |
| 1062 | bp = buf; len = PAGE_SIZE; |
| 1063 | |
| 1064 | detail->cache_request(detail, h, &bp, &len); |
| 1065 | |
| 1066 | if (len < 0) { |
| 1067 | kfree(buf); |
| 1068 | kfree(crq); |
| 1069 | return -EAGAIN; |
| 1070 | } |
| 1071 | crq->q.reader = 0; |
| 1072 | crq->item = cache_get(h); |
| 1073 | crq->buf = buf; |
| 1074 | crq->len = PAGE_SIZE - len; |
| 1075 | crq->readers = 0; |
| 1076 | spin_lock(&queue_lock); |
| 1077 | list_add_tail(&crq->q.list, &detail->queue); |
| 1078 | spin_unlock(&queue_lock); |
| 1079 | wake_up(&queue_wait); |
| 1080 | return 0; |
| 1081 | } |
| 1082 | |
| 1083 | /* |
| 1084 | * parse a message from user-space and pass it |
| 1085 | * to an appropriate cache |
| 1086 | * Messages are, like requests, separated into fields by |
| 1087 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal |
| 1088 | * |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 1089 | * Message is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | * reply cachename expiry key ... content.... |
| 1091 | * |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 1092 | * key and content are both parsed by cache |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | */ |
| 1094 | |
| 1095 | #define isodigit(c) (isdigit(c) && c <= '7') |
| 1096 | int qword_get(char **bpp, char *dest, int bufsize) |
| 1097 | { |
| 1098 | /* return bytes copied, or -1 on error */ |
| 1099 | char *bp = *bpp; |
| 1100 | int len = 0; |
| 1101 | |
| 1102 | while (*bp == ' ') bp++; |
| 1103 | |
| 1104 | if (bp[0] == '\\' && bp[1] == 'x') { |
| 1105 | /* HEX STRING */ |
| 1106 | bp += 2; |
| 1107 | while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { |
| 1108 | int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; |
| 1109 | bp++; |
| 1110 | byte <<= 4; |
| 1111 | byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; |
| 1112 | *dest++ = byte; |
| 1113 | bp++; |
| 1114 | len++; |
| 1115 | } |
| 1116 | } else { |
| 1117 | /* text with \nnn octal quoting */ |
| 1118 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { |
| 1119 | if (*bp == '\\' && |
| 1120 | isodigit(bp[1]) && (bp[1] <= '3') && |
| 1121 | isodigit(bp[2]) && |
| 1122 | isodigit(bp[3])) { |
| 1123 | int byte = (*++bp -'0'); |
| 1124 | bp++; |
| 1125 | byte = (byte << 3) | (*bp++ - '0'); |
| 1126 | byte = (byte << 3) | (*bp++ - '0'); |
| 1127 | *dest++ = byte; |
| 1128 | len++; |
| 1129 | } else { |
| 1130 | *dest++ = *bp++; |
| 1131 | len++; |
| 1132 | } |
| 1133 | } |
| 1134 | } |
| 1135 | |
| 1136 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') |
| 1137 | return -1; |
| 1138 | while (*bp == ' ') bp++; |
| 1139 | *bpp = bp; |
| 1140 | *dest = '\0'; |
| 1141 | return len; |
| 1142 | } |
Trond Myklebust | d2f7e79 | 2007-07-14 15:39:58 -0400 | [diff] [blame] | 1143 | EXPORT_SYMBOL(qword_get); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | |
| 1145 | |
| 1146 | /* |
| 1147 | * support /proc/sunrpc/cache/$CACHENAME/content |
| 1148 | * as a seqfile. |
| 1149 | * We call ->cache_show passing NULL for the item to |
| 1150 | * get a header, then pass each real item in the cache |
| 1151 | */ |
| 1152 | |
| 1153 | struct handle { |
| 1154 | struct cache_detail *cd; |
| 1155 | }; |
| 1156 | |
| 1157 | static void *c_start(struct seq_file *m, loff_t *pos) |
Eric Dumazet | 9a429c4 | 2008-01-01 21:58:02 -0800 | [diff] [blame] | 1158 | __acquires(cd->hash_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1159 | { |
| 1160 | loff_t n = *pos; |
| 1161 | unsigned hash, entry; |
| 1162 | struct cache_head *ch; |
| 1163 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 1164 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1165 | |
| 1166 | read_lock(&cd->hash_lock); |
| 1167 | if (!n--) |
| 1168 | return SEQ_START_TOKEN; |
| 1169 | hash = n >> 32; |
| 1170 | entry = n & ((1LL<<32) - 1); |
| 1171 | |
| 1172 | for (ch=cd->hash_table[hash]; ch; ch=ch->next) |
| 1173 | if (!entry--) |
| 1174 | return ch; |
| 1175 | n &= ~((1LL<<32) - 1); |
| 1176 | do { |
| 1177 | hash++; |
| 1178 | n += 1LL<<32; |
YOSHIFUJI Hideaki | cca5172 | 2007-02-09 15:38:13 -0800 | [diff] [blame] | 1179 | } while(hash < cd->hash_size && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | cd->hash_table[hash]==NULL); |
| 1181 | if (hash >= cd->hash_size) |
| 1182 | return NULL; |
| 1183 | *pos = n+1; |
| 1184 | return cd->hash_table[hash]; |
| 1185 | } |
| 1186 | |
| 1187 | static void *c_next(struct seq_file *m, void *p, loff_t *pos) |
| 1188 | { |
| 1189 | struct cache_head *ch = p; |
| 1190 | int hash = (*pos >> 32); |
| 1191 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1192 | |
| 1193 | if (p == SEQ_START_TOKEN) |
| 1194 | hash = 0; |
| 1195 | else if (ch->next == NULL) { |
| 1196 | hash++; |
| 1197 | *pos += 1LL<<32; |
| 1198 | } else { |
| 1199 | ++*pos; |
| 1200 | return ch->next; |
| 1201 | } |
| 1202 | *pos &= ~((1LL<<32) - 1); |
| 1203 | while (hash < cd->hash_size && |
| 1204 | cd->hash_table[hash] == NULL) { |
| 1205 | hash++; |
| 1206 | *pos += 1LL<<32; |
| 1207 | } |
| 1208 | if (hash >= cd->hash_size) |
| 1209 | return NULL; |
| 1210 | ++*pos; |
| 1211 | return cd->hash_table[hash]; |
| 1212 | } |
| 1213 | |
| 1214 | static void c_stop(struct seq_file *m, void *p) |
Eric Dumazet | 9a429c4 | 2008-01-01 21:58:02 -0800 | [diff] [blame] | 1215 | __releases(cd->hash_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | { |
| 1217 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1218 | read_unlock(&cd->hash_lock); |
| 1219 | } |
| 1220 | |
| 1221 | static int c_show(struct seq_file *m, void *p) |
| 1222 | { |
| 1223 | struct cache_head *cp = p; |
| 1224 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1225 | |
| 1226 | if (p == SEQ_START_TOKEN) |
| 1227 | return cd->cache_show(m, cd, NULL); |
| 1228 | |
| 1229 | ifdebug(CACHE) |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 1230 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 1231 | cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | cache_get(cp); |
| 1233 | if (cache_check(cd, cp, NULL)) |
| 1234 | /* cache_check does a cache_put on failure */ |
| 1235 | seq_printf(m, "# "); |
| 1236 | else |
| 1237 | cache_put(cp, cd); |
| 1238 | |
| 1239 | return cd->cache_show(m, cd, cp); |
| 1240 | } |
| 1241 | |
Philippe De Muyter | 56b3d97 | 2007-07-10 23:07:31 -0700 | [diff] [blame] | 1242 | static const struct seq_operations cache_content_op = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1243 | .start = c_start, |
| 1244 | .next = c_next, |
| 1245 | .stop = c_stop, |
| 1246 | .show = c_show, |
| 1247 | }; |
| 1248 | |
| 1249 | static int content_open(struct inode *inode, struct file *file) |
| 1250 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1251 | struct handle *han; |
| 1252 | struct cache_detail *cd = PDE(inode)->data; |
| 1253 | |
Pavel Emelyanov | ec93103 | 2007-10-10 02:31:07 -0700 | [diff] [blame] | 1254 | han = __seq_open_private(file, &cache_content_op, sizeof(*han)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | if (han == NULL) |
| 1256 | return -ENOMEM; |
| 1257 | |
| 1258 | han->cd = cd; |
Pavel Emelyanov | ec93103 | 2007-10-10 02:31:07 -0700 | [diff] [blame] | 1259 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1260 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | |
Arjan van de Ven | da7071d | 2007-02-12 00:55:36 -0800 | [diff] [blame] | 1262 | static const struct file_operations content_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1263 | .open = content_open, |
| 1264 | .read = seq_read, |
| 1265 | .llseek = seq_lseek, |
Martin Peschke | 14690fc | 2007-04-26 01:03:43 -0700 | [diff] [blame] | 1266 | .release = seq_release_private, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1267 | }; |
| 1268 | |
| 1269 | static ssize_t read_flush(struct file *file, char __user *buf, |
| 1270 | size_t count, loff_t *ppos) |
| 1271 | { |
Josef Sipek | 303b46b | 2006-12-08 02:37:42 -0800 | [diff] [blame] | 1272 | struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1273 | char tbuf[20]; |
| 1274 | unsigned long p = *ppos; |
Chuck Lever | 01b2969 | 2007-10-26 13:31:20 -0400 | [diff] [blame] | 1275 | size_t len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | |
| 1277 | sprintf(tbuf, "%lu\n", cd->flush_time); |
| 1278 | len = strlen(tbuf); |
| 1279 | if (p >= len) |
| 1280 | return 0; |
| 1281 | len -= p; |
Chuck Lever | 01b2969 | 2007-10-26 13:31:20 -0400 | [diff] [blame] | 1282 | if (len > count) |
| 1283 | len = count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1284 | if (copy_to_user(buf, (void*)(tbuf+p), len)) |
Chuck Lever | 01b2969 | 2007-10-26 13:31:20 -0400 | [diff] [blame] | 1285 | return -EFAULT; |
| 1286 | *ppos += len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1287 | return len; |
| 1288 | } |
| 1289 | |
| 1290 | static ssize_t write_flush(struct file * file, const char __user * buf, |
| 1291 | size_t count, loff_t *ppos) |
| 1292 | { |
Josef Sipek | 303b46b | 2006-12-08 02:37:42 -0800 | [diff] [blame] | 1293 | struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1294 | char tbuf[20]; |
| 1295 | char *ep; |
| 1296 | long flushtime; |
| 1297 | if (*ppos || count > sizeof(tbuf)-1) |
| 1298 | return -EINVAL; |
| 1299 | if (copy_from_user(tbuf, buf, count)) |
| 1300 | return -EFAULT; |
| 1301 | tbuf[count] = 0; |
| 1302 | flushtime = simple_strtoul(tbuf, &ep, 0); |
| 1303 | if (*ep && *ep != '\n') |
| 1304 | return -EINVAL; |
| 1305 | |
| 1306 | cd->flush_time = flushtime; |
| 1307 | cd->nextcheck = get_seconds(); |
| 1308 | cache_flush(); |
| 1309 | |
| 1310 | *ppos += count; |
| 1311 | return count; |
| 1312 | } |
| 1313 | |
Arjan van de Ven | da7071d | 2007-02-12 00:55:36 -0800 | [diff] [blame] | 1314 | static const struct file_operations cache_flush_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1315 | .open = nonseekable_open, |
| 1316 | .read = read_flush, |
| 1317 | .write = write_flush, |
| 1318 | }; |