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
  97 /*
  98  * object.c
  99  */
 100 extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
 101
 102 extern void fscache_withdrawing_object(struct fscache_cache *,
 103                                        struct fscache_object *);
 104 extern void fscache_enqueue_object(struct fscache_object *);
 105
 106 /*
 107  * object-list.c
 108  */
 109 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 110 extern const struct file_operations fscache_objlist_fops;
 111
 112 extern void fscache_objlist_add(struct fscache_object *);
 113 #else
 114 #define fscache_objlist_add(object) do {} while(0)
 115 #endif
 116
 117 /*
 118  * operation.c
 119  */
 120 extern int fscache_submit_exclusive_op(struct fscache_object *,
 121                                        struct fscache_operation *);
 122 extern int fscache_submit_op(struct fscache_object *,
 123                              struct fscache_operation *);
 124 extern int fscache_cancel_op(struct fscache_operation *,
 125                              void (*)(struct fscache_operation *));
 126 extern void fscache_cancel_all_ops(struct fscache_object *);
 127 extern void fscache_abort_object(struct fscache_object *);
 128 extern void fscache_start_operations(struct fscache_object *);
 129 extern void fscache_operation_gc(struct work_struct *);
 130
 131 /*
 132  * page.c
 133  */
 134 extern void fscache_invalidate_writes(struct fscache_cookie *);
 135
 136 /*
 137  * proc.c
 138  */
 139 #ifdef CONFIG_PROC_FS
 140 extern int __init fscache_proc_init(void);
 141 extern void fscache_proc_cleanup(void);
 142 #else
 143 #define fscache_proc_init()     (0)
 144 #define fscache_proc_cleanup()  do {} while (0)
 145 #endif
 146
 147 /*
 148  * stats.c
 149  */
 150 #ifdef CONFIG_FSCACHE_STATS
 151 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 152 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 153
 154 extern atomic_t fscache_n_op_pend;
 155 extern atomic_t fscache_n_op_run;
 156 extern atomic_t fscache_n_op_enqueue;
 157 extern atomic_t fscache_n_op_deferred_release;
 158 extern atomic_t fscache_n_op_release;
 159 extern atomic_t fscache_n_op_gc;
 160 extern atomic_t fscache_n_op_cancelled;
 161 extern atomic_t fscache_n_op_rejected;
 162
 163 extern atomic_t fscache_n_attr_changed;
 164 extern atomic_t fscache_n_attr_changed_ok;
 165 extern atomic_t fscache_n_attr_changed_nobufs;
 166 extern atomic_t fscache_n_attr_changed_nomem;
 167 extern atomic_t fscache_n_attr_changed_calls;
 168
 169 extern atomic_t fscache_n_allocs;
 170 extern atomic_t fscache_n_allocs_ok;
 171 extern atomic_t fscache_n_allocs_wait;
 172 extern atomic_t fscache_n_allocs_nobufs;
 173 extern atomic_t fscache_n_allocs_intr;
 174 extern atomic_t fscache_n_allocs_object_dead;
 175 extern atomic_t fscache_n_alloc_ops;
 176 extern atomic_t fscache_n_alloc_op_waits;
 177
 178 extern atomic_t fscache_n_retrievals;
 179 extern atomic_t fscache_n_retrievals_ok;
 180 extern atomic_t fscache_n_retrievals_wait;
 181 extern atomic_t fscache_n_retrievals_nodata;
 182 extern atomic_t fscache_n_retrievals_nobufs;
 183 extern atomic_t fscache_n_retrievals_intr;
 184 extern atomic_t fscache_n_retrievals_nomem;
 185 extern atomic_t fscache_n_retrievals_object_dead;
 186 extern atomic_t fscache_n_retrieval_ops;
 187 extern atomic_t fscache_n_retrieval_op_waits;
 188
 189 extern atomic_t fscache_n_stores;
 190 extern atomic_t fscache_n_stores_ok;
 191 extern atomic_t fscache_n_stores_again;
 192 extern atomic_t fscache_n_stores_nobufs;
 193 extern atomic_t fscache_n_stores_oom;
 194 extern atomic_t fscache_n_store_ops;
 195 extern atomic_t fscache_n_store_calls;
 196 extern atomic_t fscache_n_store_pages;
 197 extern atomic_t fscache_n_store_radix_deletes;
 198 extern atomic_t fscache_n_store_pages_over_limit;
 199
 200 extern atomic_t fscache_n_store_vmscan_not_storing;
 201 extern atomic_t fscache_n_store_vmscan_gone;
 202 extern atomic_t fscache_n_store_vmscan_busy;
 203 extern atomic_t fscache_n_store_vmscan_cancelled;
 204 extern atomic_t fscache_n_store_vmscan_wait;
 205
 206 extern atomic_t fscache_n_marks;
 207 extern atomic_t fscache_n_uncaches;
 208
 209 extern atomic_t fscache_n_acquires;
 210 extern atomic_t fscache_n_acquires_null;
 211 extern atomic_t fscache_n_acquires_no_cache;
 212 extern atomic_t fscache_n_acquires_ok;
 213 extern atomic_t fscache_n_acquires_nobufs;
 214 extern atomic_t fscache_n_acquires_oom;
 215
 216 extern atomic_t fscache_n_invalidates;
 217 extern atomic_t fscache_n_invalidates_run;
 218
 219 extern atomic_t fscache_n_updates;
 220 extern atomic_t fscache_n_updates_null;
 221 extern atomic_t fscache_n_updates_run;
 222
 223 extern atomic_t fscache_n_relinquishes;
 224 extern atomic_t fscache_n_relinquishes_null;
 225 extern atomic_t fscache_n_relinquishes_waitcrt;
 226 extern atomic_t fscache_n_relinquishes_retire;
 227
 228 extern atomic_t fscache_n_cookie_index;
 229 extern atomic_t fscache_n_cookie_data;
 230 extern atomic_t fscache_n_cookie_special;
 231
 232 extern atomic_t fscache_n_object_alloc;
 233 extern atomic_t fscache_n_object_no_alloc;
 234 extern atomic_t fscache_n_object_lookups;
 235 extern atomic_t fscache_n_object_lookups_negative;
 236 extern atomic_t fscache_n_object_lookups_positive;
 237 extern atomic_t fscache_n_object_lookups_timed_out;
 238 extern atomic_t fscache_n_object_created;
 239 extern atomic_t fscache_n_object_avail;
 240 extern atomic_t fscache_n_object_dead;
 241
 242 extern atomic_t fscache_n_checkaux_none;
 243 extern atomic_t fscache_n_checkaux_okay;
 244 extern atomic_t fscache_n_checkaux_update;
 245 extern atomic_t fscache_n_checkaux_obsolete;
 246
 247 extern atomic_t fscache_n_cop_alloc_object;
 248 extern atomic_t fscache_n_cop_lookup_object;
 249 extern atomic_t fscache_n_cop_lookup_complete;
 250 extern atomic_t fscache_n_cop_grab_object;
 251 extern atomic_t fscache_n_cop_invalidate_object;
 252 extern atomic_t fscache_n_cop_update_object;
 253 extern atomic_t fscache_n_cop_drop_object;
 254 extern atomic_t fscache_n_cop_put_object;
 255 extern atomic_t fscache_n_cop_sync_cache;
 256 extern atomic_t fscache_n_cop_attr_changed;
 257 extern atomic_t fscache_n_cop_read_or_alloc_page;
 258 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 259 extern atomic_t fscache_n_cop_allocate_page;
 260 extern atomic_t fscache_n_cop_allocate_pages;
 261 extern atomic_t fscache_n_cop_write_page;
 262 extern atomic_t fscache_n_cop_uncache_page;
 263 extern atomic_t fscache_n_cop_dissociate_pages;
 264
 265 static inline void fscache_stat(atomic_t *stat)
 266 {
 267         atomic_inc(stat);
 268 }
 269
 270 static inline void fscache_stat_d(atomic_t *stat)
 271 {
 272         atomic_dec(stat);
 273 }
 274
 275 #define __fscache_stat(stat) (stat)
 276
 277 extern const struct file_operations fscache_stats_fops;
 278 #else
 279
 280 #define __fscache_stat(stat) (NULL)
 281 #define fscache_stat(stat) do {} while (0)
 282 #define fscache_stat_d(stat) do {} while (0)
 283 #endif
 284
 285 /*
 286  * raise an event on an object
 287  * - if the event is not masked for that object, then the object is
 288  *   queued for attention by the thread pool.
 289  */
 290 static inline void fscache_raise_event(struct fscache_object *object,
 291                                        unsigned event)
 292 {
 293         BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 294         if (!test_and_set_bit(event, &object->events) &&
 295             test_bit(event, &object->event_mask))
 296                 fscache_enqueue_object(object);
 297 }
 298
 299 /*
 300  * drop a reference to a cookie
 301  */
 302 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 303 {
 304         BUG_ON(atomic_read(&cookie->usage) <= 0);
 305         if (atomic_dec_and_test(&cookie->usage))
 306                 __fscache_cookie_put(cookie);
 307 }
 308
 309 /*
 310  * get an extra reference to a netfs retrieval context
 311  */
 312 static inline
 313 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 314 {
 315         if (cookie->def->get_context)
 316                 cookie->def->get_context(cookie->netfs_data, context);
 317         return context;
 318 }
 319
 320 /*
 321  * release a reference to a netfs retrieval context
 322  */
 323 static inline
 324 void fscache_put_context(struct fscache_cookie *cookie, void *context)
 325 {
 326         if (cookie->def->put_context)
 327                 cookie->def->put_context(cookie->netfs_data, context);
 328 }
 329
 330 /*****************************************************************************/
 331 /*
 332  * debug tracing
 333  */
 334 #define dbgprintk(FMT, ...) \
 335         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 336
 337 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 338 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 339 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 340
 341 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 342
 343 #ifdef __KDEBUG
 344 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 345 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 346 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 347
 348 #elif defined(CONFIG_FSCACHE_DEBUG)
 349 #define _enter(FMT, ...)                        \
 350 do {                                            \
 351         if (__do_kdebug(ENTER))                 \
 352                 kenter(FMT, ##__VA_ARGS__);     \
 353 } while (0)
 354
 355 #define _leave(FMT, ...)                        \
 356 do {                                            \
 357         if (__do_kdebug(LEAVE))                 \
 358                 kleave(FMT, ##__VA_ARGS__);     \
 359 } while (0)
 360
 361 #define _debug(FMT, ...)                        \
 362 do {                                            \
 363         if (__do_kdebug(DEBUG))                 \
 364                 kdebug(FMT, ##__VA_ARGS__);     \
 365 } while (0)
 366
 367 #else
 368 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 369 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 370 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 371 #endif
 372
 373 /*
 374  * determine whether a particular optional debugging point should be logged
 375  * - we need to go through three steps to persuade cpp to correctly join the
 376  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 377  */
 378 #define ____do_kdebug(LEVEL, POINT) \
 379         unlikely((fscache_debug & \
 380                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 381 #define ___do_kdebug(LEVEL, POINT) \
 382         ____do_kdebug(LEVEL, POINT)
 383 #define __do_kdebug(POINT) \
 384         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 385
 386 #define FSCACHE_DEBUG_CACHE     0
 387 #define FSCACHE_DEBUG_COOKIE    1
 388 #define FSCACHE_DEBUG_PAGE      2
 389 #define FSCACHE_DEBUG_OPERATION 3
 390
 391 #define FSCACHE_POINT_ENTER     1
 392 #define FSCACHE_POINT_LEAVE     2
 393 #define FSCACHE_POINT_DEBUG     4
 394
 395 #ifndef FSCACHE_DEBUG_LEVEL
 396 #define FSCACHE_DEBUG_LEVEL CACHE
 397 #endif
 398
 399 /*
 400  * assertions
 401  */
 402 #if 1 /* defined(__KDEBUGALL) */
 403
 404 #define ASSERT(X)                                                       \
 405 do {                                                                    \
 406         if (unlikely(!(X))) {                                           \
 407                 printk(KERN_ERR "\n");                                  \
 408                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 409                 BUG();                                                  \
 410         }                                                               \
 411 } while (0)
 412
 413 #define ASSERTCMP(X, OP, Y)                                             \
 414 do {                                                                    \
 415         if (unlikely(!((X) OP (Y)))) {                                  \
 416                 printk(KERN_ERR "\n");                                  \
 417                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 418                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 419                        (unsigned long)(X), (unsigned long)(Y));         \
 420                 BUG();                                                  \
 421         }                                                               \
 422 } while (0)
 423
 424 #define ASSERTIF(C, X)                                                  \
 425 do {                                                                    \
 426         if (unlikely((C) && !(X))) {                                    \
 427                 printk(KERN_ERR "\n");                                  \
 428                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 429                 BUG();                                                  \
 430         }                                                               \
 431 } while (0)
 432
 433 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 434 do {                                                                    \
 435         if (unlikely((C) && !((X) OP (Y)))) {                           \
 436                 printk(KERN_ERR "\n");                                  \
 437                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 438                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 439                        (unsigned long)(X), (unsigned long)(Y));         \
 440                 BUG();                                                  \
 441         }                                                               \
 442 } while (0)
 443
 444 #else
 445
 446 #define ASSERT(X)                       do {} while (0)
 447 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 448 #define ASSERTIF(C, X)                  do {} while (0)
 449 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 450
 451 #endif /* assert or not */