fs/fscache/internal.h

   1 /* Internal definitions for FS-Cache
   2  *
   3  * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 /*
  13  * Lock order, in the order in which multiple locks should be obtained:
  14  * - fscache_addremove_sem
  15  * - cookie->lock
  16  * - cookie->parent->lock
  17  * - cache->object_list_lock
  18  * - object->lock
  19  * - object->parent->lock
  20  * - cookie->stores_lock
  21  * - fscache_thread_lock
  22  *
  23  */
  24
  25 #include <linux/fscache-cache.h>
  26 #include <linux/sched.h>
  27
  28 #define FSCACHE_MIN_THREADS     4
  29 #define FSCACHE_MAX_THREADS     32
  30
  31 /*
  32  * cache.c
  33  */
  34 extern struct list_head fscache_cache_list;
  35 extern struct rw_semaphore fscache_addremove_sem;
  36
  37 extern struct fscache_cache *fscache_select_cache_for_object(
  38         struct fscache_cookie *);
  39
  40 /*
  41  * cookie.c
  42  */
  43 extern struct kmem_cache *fscache_cookie_jar;
  44
  45 extern void fscache_cookie_init_once(void *);
  46 extern void __fscache_cookie_put(struct fscache_cookie *);
  47
  48 /*
  49  * fsdef.c
  50  */
  51 extern struct fscache_cookie fscache_fsdef_index;
  52 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  53
  54 /*
  55  * histogram.c
  56  */
  57 #ifdef CONFIG_FSCACHE_HISTOGRAM
  58 extern atomic_t fscache_obj_instantiate_histogram[HZ];
  59 extern atomic_t fscache_objs_histogram[HZ];
  60 extern atomic_t fscache_ops_histogram[HZ];
  61 extern atomic_t fscache_retrieval_delay_histogram[HZ];
  62 extern atomic_t fscache_retrieval_histogram[HZ];
  63
  64 static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
  65 {
  66         unsigned long jif = jiffies - start_jif;
  67         if (jif >= HZ)
  68                 jif = HZ - 1;
  69         atomic_inc(&histogram[jif]);
  70 }
  71
  72 extern const struct file_operations fscache_histogram_fops;
  73
  74 #else
  75 #define fscache_hist(hist, start_jif) do {} while (0)
  76 #endif
  77
  78 /*
  79  * main.c
  80  */
  81 extern unsigned fscache_defer_lookup;
  82 extern unsigned fscache_defer_create;
  83 extern unsigned fscache_debug;
  84 extern struct kobject *fscache_root;
  85
  86 extern int fscache_wait_bit(void *);
  87 extern int fscache_wait_bit_interruptible(void *);
  88
  89 /*
  90  * object.c
  91  */
  92 extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
  93
  94 extern void fscache_withdrawing_object(struct fscache_cache *,
  95                                        struct fscache_object *);
  96 extern void fscache_enqueue_object(struct fscache_object *);
  97
  98 /*
  99  * object-list.c
 100  */
 101 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 102 extern const struct file_operations fscache_objlist_fops;
 103
 104 extern void fscache_objlist_add(struct fscache_object *);
 105 #else
 106 #define fscache_objlist_add(object) do {} while(0)
 107 #endif
 108
 109 /*
 110  * operation.c
 111  */
 112 extern int fscache_submit_exclusive_op(struct fscache_object *,
 113                                        struct fscache_operation *);
 114 extern int fscache_submit_op(struct fscache_object *,
 115                              struct fscache_operation *);
 116 extern int fscache_cancel_op(struct fscache_operation *);
 117 extern void fscache_abort_object(struct fscache_object *);
 118 extern void fscache_start_operations(struct fscache_object *);
 119 extern void fscache_operation_gc(struct work_struct *);
 120
 121 /*
 122  * proc.c
 123  */
 124 #ifdef CONFIG_PROC_FS
 125 extern int __init fscache_proc_init(void);
 126 extern void fscache_proc_cleanup(void);
 127 #else
 128 #define fscache_proc_init()     (0)
 129 #define fscache_proc_cleanup()  do {} while (0)
 130 #endif
 131
 132 /*
 133  * stats.c
 134  */
 135 #ifdef CONFIG_FSCACHE_STATS
 136 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 137 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 138
 139 extern atomic_t fscache_n_op_pend;
 140 extern atomic_t fscache_n_op_run;
 141 extern atomic_t fscache_n_op_enqueue;
 142 extern atomic_t fscache_n_op_deferred_release;
 143 extern atomic_t fscache_n_op_release;
 144 extern atomic_t fscache_n_op_gc;
 145 extern atomic_t fscache_n_op_cancelled;
 146 extern atomic_t fscache_n_op_rejected;
 147
 148 extern atomic_t fscache_n_attr_changed;
 149 extern atomic_t fscache_n_attr_changed_ok;
 150 extern atomic_t fscache_n_attr_changed_nobufs;
 151 extern atomic_t fscache_n_attr_changed_nomem;
 152 extern atomic_t fscache_n_attr_changed_calls;
 153
 154 extern atomic_t fscache_n_allocs;
 155 extern atomic_t fscache_n_allocs_ok;
 156 extern atomic_t fscache_n_allocs_wait;
 157 extern atomic_t fscache_n_allocs_nobufs;
 158 extern atomic_t fscache_n_allocs_intr;
 159 extern atomic_t fscache_n_allocs_object_dead;
 160 extern atomic_t fscache_n_alloc_ops;
 161 extern atomic_t fscache_n_alloc_op_waits;
 162
 163 extern atomic_t fscache_n_retrievals;
 164 extern atomic_t fscache_n_retrievals_ok;
 165 extern atomic_t fscache_n_retrievals_wait;
 166 extern atomic_t fscache_n_retrievals_nodata;
 167 extern atomic_t fscache_n_retrievals_nobufs;
 168 extern atomic_t fscache_n_retrievals_intr;
 169 extern atomic_t fscache_n_retrievals_nomem;
 170 extern atomic_t fscache_n_retrievals_object_dead;
 171 extern atomic_t fscache_n_retrieval_ops;
 172 extern atomic_t fscache_n_retrieval_op_waits;
 173
 174 extern atomic_t fscache_n_stores;
 175 extern atomic_t fscache_n_stores_ok;
 176 extern atomic_t fscache_n_stores_again;
 177 extern atomic_t fscache_n_stores_nobufs;
 178 extern atomic_t fscache_n_stores_oom;
 179 extern atomic_t fscache_n_store_ops;
 180 extern atomic_t fscache_n_store_calls;
 181 extern atomic_t fscache_n_store_pages;
 182 extern atomic_t fscache_n_store_radix_deletes;
 183 extern atomic_t fscache_n_store_pages_over_limit;
 184
 185 extern atomic_t fscache_n_store_vmscan_not_storing;
 186 extern atomic_t fscache_n_store_vmscan_gone;
 187 extern atomic_t fscache_n_store_vmscan_busy;
 188 extern atomic_t fscache_n_store_vmscan_cancelled;
 189
 190 extern atomic_t fscache_n_marks;
 191 extern atomic_t fscache_n_uncaches;
 192
 193 extern atomic_t fscache_n_acquires;
 194 extern atomic_t fscache_n_acquires_null;
 195 extern atomic_t fscache_n_acquires_no_cache;
 196 extern atomic_t fscache_n_acquires_ok;
 197 extern atomic_t fscache_n_acquires_nobufs;
 198 extern atomic_t fscache_n_acquires_oom;
 199
 200 extern atomic_t fscache_n_updates;
 201 extern atomic_t fscache_n_updates_null;
 202 extern atomic_t fscache_n_updates_run;
 203
 204 extern atomic_t fscache_n_relinquishes;
 205 extern atomic_t fscache_n_relinquishes_null;
 206 extern atomic_t fscache_n_relinquishes_waitcrt;
 207 extern atomic_t fscache_n_relinquishes_retire;
 208
 209 extern atomic_t fscache_n_cookie_index;
 210 extern atomic_t fscache_n_cookie_data;
 211 extern atomic_t fscache_n_cookie_special;
 212
 213 extern atomic_t fscache_n_object_alloc;
 214 extern atomic_t fscache_n_object_no_alloc;
 215 extern atomic_t fscache_n_object_lookups;
 216 extern atomic_t fscache_n_object_lookups_negative;
 217 extern atomic_t fscache_n_object_lookups_positive;
 218 extern atomic_t fscache_n_object_lookups_timed_out;
 219 extern atomic_t fscache_n_object_created;
 220 extern atomic_t fscache_n_object_avail;
 221 extern atomic_t fscache_n_object_dead;
 222
 223 extern atomic_t fscache_n_checkaux_none;
 224 extern atomic_t fscache_n_checkaux_okay;
 225 extern atomic_t fscache_n_checkaux_update;
 226 extern atomic_t fscache_n_checkaux_obsolete;
 227
 228 extern atomic_t fscache_n_cop_alloc_object;
 229 extern atomic_t fscache_n_cop_lookup_object;
 230 extern atomic_t fscache_n_cop_lookup_complete;
 231 extern atomic_t fscache_n_cop_grab_object;
 232 extern atomic_t fscache_n_cop_update_object;
 233 extern atomic_t fscache_n_cop_drop_object;
 234 extern atomic_t fscache_n_cop_put_object;
 235 extern atomic_t fscache_n_cop_sync_cache;
 236 extern atomic_t fscache_n_cop_attr_changed;
 237 extern atomic_t fscache_n_cop_read_or_alloc_page;
 238 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 239 extern atomic_t fscache_n_cop_allocate_page;
 240 extern atomic_t fscache_n_cop_allocate_pages;
 241 extern atomic_t fscache_n_cop_write_page;
 242 extern atomic_t fscache_n_cop_uncache_page;
 243 extern atomic_t fscache_n_cop_dissociate_pages;
 244
 245 static inline void fscache_stat(atomic_t *stat)
 246 {
 247         atomic_inc(stat);
 248 }
 249
 250 static inline void fscache_stat_d(atomic_t *stat)
 251 {
 252         atomic_dec(stat);
 253 }
 254
 255 #define __fscache_stat(stat) (stat)
 256
 257 extern const struct file_operations fscache_stats_fops;
 258 #else
 259
 260 #define __fscache_stat(stat) (NULL)
 261 #define fscache_stat(stat) do {} while (0)
 262 #define fscache_stat_d(stat) do {} while (0)
 263 #endif
 264
 265 /*
 266  * raise an event on an object
 267  * - if the event is not masked for that object, then the object is
 268  *   queued for attention by the thread pool.
 269  */
 270 static inline void fscache_raise_event(struct fscache_object *object,
 271                                        unsigned event)
 272 {
 273         if (!test_and_set_bit(event, &object->events) &&
 274             test_bit(event, &object->event_mask))
 275                 fscache_enqueue_object(object);
 276 }
 277
 278 /*
 279  * drop a reference to a cookie
 280  */
 281 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 282 {
 283         BUG_ON(atomic_read(&cookie->usage) <= 0);
 284         if (atomic_dec_and_test(&cookie->usage))
 285                 __fscache_cookie_put(cookie);
 286 }
 287
 288 /*
 289  * get an extra reference to a netfs retrieval context
 290  */
 291 static inline
 292 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 293 {
 294         if (cookie->def->get_context)
 295                 cookie->def->get_context(cookie->netfs_data, context);
 296         return context;
 297 }
 298
 299 /*
 300  * release a reference to a netfs retrieval context
 301  */
 302 static inline
 303 void fscache_put_context(struct fscache_cookie *cookie, void *context)
 304 {
 305         if (cookie->def->put_context)
 306                 cookie->def->put_context(cookie->netfs_data, context);
 307 }
 308
 309 /*****************************************************************************/
 310 /*
 311  * debug tracing
 312  */
 313 #define dbgprintk(FMT, ...) \
 314         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 315
 316 /* make sure we maintain the format strings, even when debugging is disabled */
 317 static inline __attribute__((format(printf, 1, 2)))
 318 void _dbprintk(const char *fmt, ...)
 319 {
 320 }
 321
 322 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 323 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 324 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 325
 326 #define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
 327
 328 #ifdef __KDEBUG
 329 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 330 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 331 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 332
 333 #elif defined(CONFIG_FSCACHE_DEBUG)
 334 #define _enter(FMT, ...)                        \
 335 do {                                            \
 336         if (__do_kdebug(ENTER))                 \
 337                 kenter(FMT, ##__VA_ARGS__);     \
 338 } while (0)
 339
 340 #define _leave(FMT, ...)                        \
 341 do {                                            \
 342         if (__do_kdebug(LEAVE))                 \
 343                 kleave(FMT, ##__VA_ARGS__);     \
 344 } while (0)
 345
 346 #define _debug(FMT, ...)                        \
 347 do {                                            \
 348         if (__do_kdebug(DEBUG))                 \
 349                 kdebug(FMT, ##__VA_ARGS__);     \
 350 } while (0)
 351
 352 #else
 353 #define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 354 #define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 355 #define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
 356 #endif
 357
 358 /*
 359  * determine whether a particular optional debugging point should be logged
 360  * - we need to go through three steps to persuade cpp to correctly join the
 361  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 362  */
 363 #define ____do_kdebug(LEVEL, POINT) \
 364         unlikely((fscache_debug & \
 365                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 366 #define ___do_kdebug(LEVEL, POINT) \
 367         ____do_kdebug(LEVEL, POINT)
 368 #define __do_kdebug(POINT) \
 369         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 370
 371 #define FSCACHE_DEBUG_CACHE     0
 372 #define FSCACHE_DEBUG_COOKIE    1
 373 #define FSCACHE_DEBUG_PAGE      2
 374 #define FSCACHE_DEBUG_OPERATION 3
 375
 376 #define FSCACHE_POINT_ENTER     1
 377 #define FSCACHE_POINT_LEAVE     2
 378 #define FSCACHE_POINT_DEBUG     4
 379
 380 #ifndef FSCACHE_DEBUG_LEVEL
 381 #define FSCACHE_DEBUG_LEVEL CACHE
 382 #endif
 383
 384 /*
 385  * assertions
 386  */
 387 #if 1 /* defined(__KDEBUGALL) */
 388
 389 #define ASSERT(X)                                                       \
 390 do {                                                                    \
 391         if (unlikely(!(X))) {                                           \
 392                 printk(KERN_ERR "\n");                                  \
 393                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 394                 BUG();                                                  \
 395         }                                                               \
 396 } while (0)
 397
 398 #define ASSERTCMP(X, OP, Y)                                             \
 399 do {                                                                    \
 400         if (unlikely(!((X) OP (Y)))) {                                  \
 401                 printk(KERN_ERR "\n");                                  \
 402                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 403                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 404                        (unsigned long)(X), (unsigned long)(Y));         \
 405                 BUG();                                                  \
 406         }                                                               \
 407 } while (0)
 408
 409 #define ASSERTIF(C, X)                                                  \
 410 do {                                                                    \
 411         if (unlikely((C) && !(X))) {                                    \
 412                 printk(KERN_ERR "\n");                                  \
 413                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 414                 BUG();                                                  \
 415         }                                                               \
 416 } while (0)
 417
 418 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 419 do {                                                                    \
 420         if (unlikely((C) && !((X) OP (Y)))) {                           \
 421                 printk(KERN_ERR "\n");                                  \
 422                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 423                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 424                        (unsigned long)(X), (unsigned long)(Y));         \
 425                 BUG();                                                  \
 426         }                                                               \
 427 } while (0)
 428
 429 #else
 430
 431 #define ASSERT(X)                       do {} while (0)
 432 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 433 #define ASSERTIF(C, X)                  do {} while (0)
 434 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 435
 436 #endif /* assert or not */