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_alloc_ops;
 160 extern atomic_t fscache_n_alloc_op_waits;
 161
 162 extern atomic_t fscache_n_retrievals;
 163 extern atomic_t fscache_n_retrievals_ok;
 164 extern atomic_t fscache_n_retrievals_wait;
 165 extern atomic_t fscache_n_retrievals_nodata;
 166 extern atomic_t fscache_n_retrievals_nobufs;
 167 extern atomic_t fscache_n_retrievals_intr;
 168 extern atomic_t fscache_n_retrievals_nomem;
 169 extern atomic_t fscache_n_retrieval_ops;
 170 extern atomic_t fscache_n_retrieval_op_waits;
 171
 172 extern atomic_t fscache_n_stores;
 173 extern atomic_t fscache_n_stores_ok;
 174 extern atomic_t fscache_n_stores_again;
 175 extern atomic_t fscache_n_stores_nobufs;
 176 extern atomic_t fscache_n_stores_oom;
 177 extern atomic_t fscache_n_store_ops;
 178 extern atomic_t fscache_n_store_calls;
 179 extern atomic_t fscache_n_store_pages;
 180 extern atomic_t fscache_n_store_radix_deletes;
 181 extern atomic_t fscache_n_store_pages_over_limit;
 182
 183 extern atomic_t fscache_n_store_vmscan_not_storing;
 184 extern atomic_t fscache_n_store_vmscan_gone;
 185 extern atomic_t fscache_n_store_vmscan_busy;
 186 extern atomic_t fscache_n_store_vmscan_cancelled;
 187
 188 extern atomic_t fscache_n_marks;
 189 extern atomic_t fscache_n_uncaches;
 190
 191 extern atomic_t fscache_n_acquires;
 192 extern atomic_t fscache_n_acquires_null;
 193 extern atomic_t fscache_n_acquires_no_cache;
 194 extern atomic_t fscache_n_acquires_ok;
 195 extern atomic_t fscache_n_acquires_nobufs;
 196 extern atomic_t fscache_n_acquires_oom;
 197
 198 extern atomic_t fscache_n_updates;
 199 extern atomic_t fscache_n_updates_null;
 200 extern atomic_t fscache_n_updates_run;
 201
 202 extern atomic_t fscache_n_relinquishes;
 203 extern atomic_t fscache_n_relinquishes_null;
 204 extern atomic_t fscache_n_relinquishes_waitcrt;
 205
 206 extern atomic_t fscache_n_cookie_index;
 207 extern atomic_t fscache_n_cookie_data;
 208 extern atomic_t fscache_n_cookie_special;
 209
 210 extern atomic_t fscache_n_object_alloc;
 211 extern atomic_t fscache_n_object_no_alloc;
 212 extern atomic_t fscache_n_object_lookups;
 213 extern atomic_t fscache_n_object_lookups_negative;
 214 extern atomic_t fscache_n_object_lookups_positive;
 215 extern atomic_t fscache_n_object_created;
 216 extern atomic_t fscache_n_object_avail;
 217 extern atomic_t fscache_n_object_dead;
 218
 219 extern atomic_t fscache_n_checkaux_none;
 220 extern atomic_t fscache_n_checkaux_okay;
 221 extern atomic_t fscache_n_checkaux_update;
 222 extern atomic_t fscache_n_checkaux_obsolete;
 223
 224 extern atomic_t fscache_n_cop_alloc_object;
 225 extern atomic_t fscache_n_cop_lookup_object;
 226 extern atomic_t fscache_n_cop_lookup_complete;
 227 extern atomic_t fscache_n_cop_grab_object;
 228 extern atomic_t fscache_n_cop_update_object;
 229 extern atomic_t fscache_n_cop_drop_object;
 230 extern atomic_t fscache_n_cop_put_object;
 231 extern atomic_t fscache_n_cop_sync_cache;
 232 extern atomic_t fscache_n_cop_attr_changed;
 233 extern atomic_t fscache_n_cop_read_or_alloc_page;
 234 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 235 extern atomic_t fscache_n_cop_allocate_page;
 236 extern atomic_t fscache_n_cop_allocate_pages;
 237 extern atomic_t fscache_n_cop_write_page;
 238 extern atomic_t fscache_n_cop_uncache_page;
 239 extern atomic_t fscache_n_cop_dissociate_pages;
 240
 241 static inline void fscache_stat(atomic_t *stat)
 242 {
 243         atomic_inc(stat);
 244 }
 245
 246 static inline void fscache_stat_d(atomic_t *stat)
 247 {
 248         atomic_dec(stat);
 249 }
 250
 251 extern const struct file_operations fscache_stats_fops;
 252 #else
 253
 254 #define fscache_stat(stat) do {} while (0)
 255 #endif
 256
 257 /*
 258  * raise an event on an object
 259  * - if the event is not masked for that object, then the object is
 260  *   queued for attention by the thread pool.
 261  */
 262 static inline void fscache_raise_event(struct fscache_object *object,
 263                                        unsigned event)
 264 {
 265         if (!test_and_set_bit(event, &object->events) &&
 266             test_bit(event, &object->event_mask))
 267                 fscache_enqueue_object(object);
 268 }
 269
 270 /*
 271  * drop a reference to a cookie
 272  */
 273 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 274 {
 275         BUG_ON(atomic_read(&cookie->usage) <= 0);
 276         if (atomic_dec_and_test(&cookie->usage))
 277                 __fscache_cookie_put(cookie);
 278 }
 279
 280 /*
 281  * get an extra reference to a netfs retrieval context
 282  */
 283 static inline
 284 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 285 {
 286         if (cookie->def->get_context)
 287                 cookie->def->get_context(cookie->netfs_data, context);
 288         return context;
 289 }
 290
 291 /*
 292  * release a reference to a netfs retrieval context
 293  */
 294 static inline
 295 void fscache_put_context(struct fscache_cookie *cookie, void *context)
 296 {
 297         if (cookie->def->put_context)
 298                 cookie->def->put_context(cookie->netfs_data, context);
 299 }
 300
 301 /*****************************************************************************/
 302 /*
 303  * debug tracing
 304  */
 305 #define dbgprintk(FMT, ...) \
 306         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 307
 308 /* make sure we maintain the format strings, even when debugging is disabled */
 309 static inline __attribute__((format(printf, 1, 2)))
 310 void _dbprintk(const char *fmt, ...)
 311 {
 312 }
 313
 314 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 315 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 316 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 317
 318 #define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
 319
 320 #ifdef __KDEBUG
 321 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 322 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 323 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 324
 325 #elif defined(CONFIG_FSCACHE_DEBUG)
 326 #define _enter(FMT, ...)                        \
 327 do {                                            \
 328         if (__do_kdebug(ENTER))                 \
 329                 kenter(FMT, ##__VA_ARGS__);     \
 330 } while (0)
 331
 332 #define _leave(FMT, ...)                        \
 333 do {                                            \
 334         if (__do_kdebug(LEAVE))                 \
 335                 kleave(FMT, ##__VA_ARGS__);     \
 336 } while (0)
 337
 338 #define _debug(FMT, ...)                        \
 339 do {                                            \
 340         if (__do_kdebug(DEBUG))                 \
 341                 kdebug(FMT, ##__VA_ARGS__);     \
 342 } while (0)
 343
 344 #else
 345 #define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 346 #define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 347 #define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
 348 #endif
 349
 350 /*
 351  * determine whether a particular optional debugging point should be logged
 352  * - we need to go through three steps to persuade cpp to correctly join the
 353  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 354  */
 355 #define ____do_kdebug(LEVEL, POINT) \
 356         unlikely((fscache_debug & \
 357                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 358 #define ___do_kdebug(LEVEL, POINT) \
 359         ____do_kdebug(LEVEL, POINT)
 360 #define __do_kdebug(POINT) \
 361         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 362
 363 #define FSCACHE_DEBUG_CACHE     0
 364 #define FSCACHE_DEBUG_COOKIE    1
 365 #define FSCACHE_DEBUG_PAGE      2
 366 #define FSCACHE_DEBUG_OPERATION 3
 367
 368 #define FSCACHE_POINT_ENTER     1
 369 #define FSCACHE_POINT_LEAVE     2
 370 #define FSCACHE_POINT_DEBUG     4
 371
 372 #ifndef FSCACHE_DEBUG_LEVEL
 373 #define FSCACHE_DEBUG_LEVEL CACHE
 374 #endif
 375
 376 /*
 377  * assertions
 378  */
 379 #if 1 /* defined(__KDEBUGALL) */
 380
 381 #define ASSERT(X)                                                       \
 382 do {                                                                    \
 383         if (unlikely(!(X))) {                                           \
 384                 printk(KERN_ERR "\n");                                  \
 385                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 386                 BUG();                                                  \
 387         }                                                               \
 388 } while (0)
 389
 390 #define ASSERTCMP(X, OP, Y)                                             \
 391 do {                                                                    \
 392         if (unlikely(!((X) OP (Y)))) {                                  \
 393                 printk(KERN_ERR "\n");                                  \
 394                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 395                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 396                        (unsigned long)(X), (unsigned long)(Y));         \
 397                 BUG();                                                  \
 398         }                                                               \
 399 } while (0)
 400
 401 #define ASSERTIF(C, X)                                                  \
 402 do {                                                                    \
 403         if (unlikely((C) && !(X))) {                                    \
 404                 printk(KERN_ERR "\n");                                  \
 405                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 406                 BUG();                                                  \
 407         }                                                               \
 408 } while (0)
 409
 410 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 411 do {                                                                    \
 412         if (unlikely((C) && !((X) OP (Y)))) {                           \
 413                 printk(KERN_ERR "\n");                                  \
 414                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 415                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 416                        (unsigned long)(X), (unsigned long)(Y));         \
 417                 BUG();                                                  \
 418         }                                                               \
 419 } while (0)
 420
 421 #else
 422
 423 #define ASSERT(X)                       do {} while (0)
 424 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 425 #define ASSERTIF(C, X)                  do {} while (0)
 426 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 427
 428 #endif /* assert or not */