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 extern struct workqueue_struct *fscache_object_wq;
  86 extern struct workqueue_struct *fscache_op_wq;
  87 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  88
  89 static inline bool fscache_object_congested(void)
  90 {
  91         return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  92 }
  93
  94 extern int fscache_wait_bit(void *);
  95 extern int fscache_wait_bit_interruptible(void *);
  96 extern int fscache_wait_atomic_t(atomic_t *);
  97
  98 /*
  99  * object.c
 100  */
 101 extern void fscache_enqueue_object(struct fscache_object *);
 102
 103 /*
 104  * object-list.c
 105  */
 106 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 107 extern const struct file_operations fscache_objlist_fops;
 108
 109 extern void fscache_objlist_add(struct fscache_object *);
 110 extern void fscache_objlist_remove(struct fscache_object *);
 111 #else
 112 #define fscache_objlist_add(object) do {} while(0)
 113 #define fscache_objlist_remove(object) do {} while(0)
 114 #endif
 115
 116 /*
 117  * operation.c
 118  */
 119 extern int fscache_submit_exclusive_op(struct fscache_object *,
 120                                        struct fscache_operation *);
 121 extern int fscache_submit_op(struct fscache_object *,
 122                              struct fscache_operation *);
 123 extern int fscache_cancel_op(struct fscache_operation *,
 124                              void (*)(struct fscache_operation *));
 125 extern void fscache_cancel_all_ops(struct fscache_object *);
 126 extern void fscache_abort_object(struct fscache_object *);
 127 extern void fscache_start_operations(struct fscache_object *);
 128 extern void fscache_operation_gc(struct work_struct *);
 129
 130 /*
 131  * page.c
 132  */
 133 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 134 extern int fscache_wait_for_operation_activation(struct fscache_object *,
 135                                                  struct fscache_operation *,
 136                                                  atomic_t *,
 137                                                  atomic_t *,
 138                                                  void (*)(struct fscache_operation *));
 139 extern void fscache_invalidate_writes(struct fscache_cookie *);
 140
 141 /*
 142  * proc.c
 143  */
 144 #ifdef CONFIG_PROC_FS
 145 extern int __init fscache_proc_init(void);
 146 extern void fscache_proc_cleanup(void);
 147 #else
 148 #define fscache_proc_init()     (0)
 149 #define fscache_proc_cleanup()  do {} while (0)
 150 #endif
 151
 152 /*
 153  * stats.c
 154  */
 155 #ifdef CONFIG_FSCACHE_STATS
 156 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 157 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 158
 159 extern atomic_t fscache_n_op_pend;
 160 extern atomic_t fscache_n_op_run;
 161 extern atomic_t fscache_n_op_enqueue;
 162 extern atomic_t fscache_n_op_deferred_release;
 163 extern atomic_t fscache_n_op_release;
 164 extern atomic_t fscache_n_op_gc;
 165 extern atomic_t fscache_n_op_cancelled;
 166 extern atomic_t fscache_n_op_rejected;
 167
 168 extern atomic_t fscache_n_attr_changed;
 169 extern atomic_t fscache_n_attr_changed_ok;
 170 extern atomic_t fscache_n_attr_changed_nobufs;
 171 extern atomic_t fscache_n_attr_changed_nomem;
 172 extern atomic_t fscache_n_attr_changed_calls;
 173
 174 extern atomic_t fscache_n_allocs;
 175 extern atomic_t fscache_n_allocs_ok;
 176 extern atomic_t fscache_n_allocs_wait;
 177 extern atomic_t fscache_n_allocs_nobufs;
 178 extern atomic_t fscache_n_allocs_intr;
 179 extern atomic_t fscache_n_allocs_object_dead;
 180 extern atomic_t fscache_n_alloc_ops;
 181 extern atomic_t fscache_n_alloc_op_waits;
 182
 183 extern atomic_t fscache_n_retrievals;
 184 extern atomic_t fscache_n_retrievals_ok;
 185 extern atomic_t fscache_n_retrievals_wait;
 186 extern atomic_t fscache_n_retrievals_nodata;
 187 extern atomic_t fscache_n_retrievals_nobufs;
 188 extern atomic_t fscache_n_retrievals_intr;
 189 extern atomic_t fscache_n_retrievals_nomem;
 190 extern atomic_t fscache_n_retrievals_object_dead;
 191 extern atomic_t fscache_n_retrieval_ops;
 192 extern atomic_t fscache_n_retrieval_op_waits;
 193
 194 extern atomic_t fscache_n_stores;
 195 extern atomic_t fscache_n_stores_ok;
 196 extern atomic_t fscache_n_stores_again;
 197 extern atomic_t fscache_n_stores_nobufs;
 198 extern atomic_t fscache_n_stores_oom;
 199 extern atomic_t fscache_n_store_ops;
 200 extern atomic_t fscache_n_store_calls;
 201 extern atomic_t fscache_n_store_pages;
 202 extern atomic_t fscache_n_store_radix_deletes;
 203 extern atomic_t fscache_n_store_pages_over_limit;
 204
 205 extern atomic_t fscache_n_store_vmscan_not_storing;
 206 extern atomic_t fscache_n_store_vmscan_gone;
 207 extern atomic_t fscache_n_store_vmscan_busy;
 208 extern atomic_t fscache_n_store_vmscan_cancelled;
 209 extern atomic_t fscache_n_store_vmscan_wait;
 210
 211 extern atomic_t fscache_n_marks;
 212 extern atomic_t fscache_n_uncaches;
 213
 214 extern atomic_t fscache_n_acquires;
 215 extern atomic_t fscache_n_acquires_null;
 216 extern atomic_t fscache_n_acquires_no_cache;
 217 extern atomic_t fscache_n_acquires_ok;
 218 extern atomic_t fscache_n_acquires_nobufs;
 219 extern atomic_t fscache_n_acquires_oom;
 220
 221 extern atomic_t fscache_n_invalidates;
 222 extern atomic_t fscache_n_invalidates_run;
 223
 224 extern atomic_t fscache_n_updates;
 225 extern atomic_t fscache_n_updates_null;
 226 extern atomic_t fscache_n_updates_run;
 227
 228 extern atomic_t fscache_n_relinquishes;
 229 extern atomic_t fscache_n_relinquishes_null;
 230 extern atomic_t fscache_n_relinquishes_waitcrt;
 231 extern atomic_t fscache_n_relinquishes_retire;
 232
 233 extern atomic_t fscache_n_cookie_index;
 234 extern atomic_t fscache_n_cookie_data;
 235 extern atomic_t fscache_n_cookie_special;
 236
 237 extern atomic_t fscache_n_object_alloc;
 238 extern atomic_t fscache_n_object_no_alloc;
 239 extern atomic_t fscache_n_object_lookups;
 240 extern atomic_t fscache_n_object_lookups_negative;
 241 extern atomic_t fscache_n_object_lookups_positive;
 242 extern atomic_t fscache_n_object_lookups_timed_out;
 243 extern atomic_t fscache_n_object_created;
 244 extern atomic_t fscache_n_object_avail;
 245 extern atomic_t fscache_n_object_dead;
 246
 247 extern atomic_t fscache_n_checkaux_none;
 248 extern atomic_t fscache_n_checkaux_okay;
 249 extern atomic_t fscache_n_checkaux_update;
 250 extern atomic_t fscache_n_checkaux_obsolete;
 251
 252 extern atomic_t fscache_n_cop_alloc_object;
 253 extern atomic_t fscache_n_cop_lookup_object;
 254 extern atomic_t fscache_n_cop_lookup_complete;
 255 extern atomic_t fscache_n_cop_grab_object;
 256 extern atomic_t fscache_n_cop_invalidate_object;
 257 extern atomic_t fscache_n_cop_update_object;
 258 extern atomic_t fscache_n_cop_drop_object;
 259 extern atomic_t fscache_n_cop_put_object;
 260 extern atomic_t fscache_n_cop_sync_cache;
 261 extern atomic_t fscache_n_cop_attr_changed;
 262 extern atomic_t fscache_n_cop_read_or_alloc_page;
 263 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 264 extern atomic_t fscache_n_cop_allocate_page;
 265 extern atomic_t fscache_n_cop_allocate_pages;
 266 extern atomic_t fscache_n_cop_write_page;
 267 extern atomic_t fscache_n_cop_uncache_page;
 268 extern atomic_t fscache_n_cop_dissociate_pages;
 269
 270 static inline void fscache_stat(atomic_t *stat)
 271 {
 272         atomic_inc(stat);
 273 }
 274
 275 static inline void fscache_stat_d(atomic_t *stat)
 276 {
 277         atomic_dec(stat);
 278 }
 279
 280 #define __fscache_stat(stat) (stat)
 281
 282 extern const struct file_operations fscache_stats_fops;
 283 #else
 284
 285 #define __fscache_stat(stat) (NULL)
 286 #define fscache_stat(stat) do {} while (0)
 287 #define fscache_stat_d(stat) do {} while (0)
 288 #endif
 289
 290 /*
 291  * raise an event on an object
 292  * - if the event is not masked for that object, then the object is
 293  *   queued for attention by the thread pool.
 294  */
 295 static inline void fscache_raise_event(struct fscache_object *object,
 296                                        unsigned event)
 297 {
 298         BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 299 #if 0
 300         printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
 301                object->debug_id, object->event_mask, (1 << event));
 302 #endif
 303         if (!test_and_set_bit(event, &object->events) &&
 304             test_bit(event, &object->event_mask))
 305                 fscache_enqueue_object(object);
 306 }
 307
 308 /*
 309  * drop a reference to a cookie
 310  */
 311 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 312 {
 313         BUG_ON(atomic_read(&cookie->usage) <= 0);
 314         if (atomic_dec_and_test(&cookie->usage))
 315                 __fscache_cookie_put(cookie);
 316 }
 317
 318 /*
 319  * get an extra reference to a netfs retrieval context
 320  */
 321 static inline
 322 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 323 {
 324         if (cookie->def->get_context)
 325                 cookie->def->get_context(cookie->netfs_data, context);
 326         return context;
 327 }
 328
 329 /*
 330  * release a reference to a netfs retrieval context
 331  */
 332 static inline
 333 void fscache_put_context(struct fscache_cookie *cookie, void *context)
 334 {
 335         if (cookie->def->put_context)
 336                 cookie->def->put_context(cookie->netfs_data, context);
 337 }
 338
 339 /*****************************************************************************/
 340 /*
 341  * debug tracing
 342  */
 343 #define dbgprintk(FMT, ...) \
 344         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 345
 346 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 347 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 348 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 349
 350 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 351
 352 #ifdef __KDEBUG
 353 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 354 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 355 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 356
 357 #elif defined(CONFIG_FSCACHE_DEBUG)
 358 #define _enter(FMT, ...)                        \
 359 do {                                            \
 360         if (__do_kdebug(ENTER))                 \
 361                 kenter(FMT, ##__VA_ARGS__);     \
 362 } while (0)
 363
 364 #define _leave(FMT, ...)                        \
 365 do {                                            \
 366         if (__do_kdebug(LEAVE))                 \
 367                 kleave(FMT, ##__VA_ARGS__);     \
 368 } while (0)
 369
 370 #define _debug(FMT, ...)                        \
 371 do {                                            \
 372         if (__do_kdebug(DEBUG))                 \
 373                 kdebug(FMT, ##__VA_ARGS__);     \
 374 } while (0)
 375
 376 #else
 377 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 378 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 379 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 380 #endif
 381
 382 /*
 383  * determine whether a particular optional debugging point should be logged
 384  * - we need to go through three steps to persuade cpp to correctly join the
 385  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 386  */
 387 #define ____do_kdebug(LEVEL, POINT) \
 388         unlikely((fscache_debug & \
 389                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 390 #define ___do_kdebug(LEVEL, POINT) \
 391         ____do_kdebug(LEVEL, POINT)
 392 #define __do_kdebug(POINT) \
 393         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 394
 395 #define FSCACHE_DEBUG_CACHE     0
 396 #define FSCACHE_DEBUG_COOKIE    1
 397 #define FSCACHE_DEBUG_PAGE      2
 398 #define FSCACHE_DEBUG_OPERATION 3
 399
 400 #define FSCACHE_POINT_ENTER     1
 401 #define FSCACHE_POINT_LEAVE     2
 402 #define FSCACHE_POINT_DEBUG     4
 403
 404 #ifndef FSCACHE_DEBUG_LEVEL
 405 #define FSCACHE_DEBUG_LEVEL CACHE
 406 #endif
 407
 408 /*
 409  * assertions
 410  */
 411 #if 1 /* defined(__KDEBUGALL) */
 412
 413 #define ASSERT(X)                                                       \
 414 do {                                                                    \
 415         if (unlikely(!(X))) {                                           \
 416                 printk(KERN_ERR "\n");                                  \
 417                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 418                 BUG();                                                  \
 419         }                                                               \
 420 } while (0)
 421
 422 #define ASSERTCMP(X, OP, Y)                                             \
 423 do {                                                                    \
 424         if (unlikely(!((X) OP (Y)))) {                                  \
 425                 printk(KERN_ERR "\n");                                  \
 426                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 427                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 428                        (unsigned long)(X), (unsigned long)(Y));         \
 429                 BUG();                                                  \
 430         }                                                               \
 431 } while (0)
 432
 433 #define ASSERTIF(C, X)                                                  \
 434 do {                                                                    \
 435         if (unlikely((C) && !(X))) {                                    \
 436                 printk(KERN_ERR "\n");                                  \
 437                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 438                 BUG();                                                  \
 439         }                                                               \
 440 } while (0)
 441
 442 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 443 do {                                                                    \
 444         if (unlikely((C) && !((X) OP (Y)))) {                           \
 445                 printk(KERN_ERR "\n");                                  \
 446                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 447                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 448                        (unsigned long)(X), (unsigned long)(Y));         \
 449                 BUG();                                                  \
 450         }                                                               \
 451 } while (0)
 452
 453 #else
 454
 455 #define ASSERT(X)                       do {} while (0)
 456 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 457 #define ASSERTIF(C, X)                  do {} while (0)
 458 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 459
 460 #endif /* assert or not */