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 #ifdef pr_fmt
  26 #undef pr_fmt
  27 #endif
  28
  29 #define pr_fmt(fmt) "FS-Cache: " fmt
  30
  31 #include <linux/fscache-cache.h>
  32 #include <linux/sched.h>
  33
  34 #define FSCACHE_MIN_THREADS     4
  35 #define FSCACHE_MAX_THREADS     32
  36
  37 /*
  38  * cache.c
  39  */
  40 extern struct list_head fscache_cache_list;
  41 extern struct rw_semaphore fscache_addremove_sem;
  42
  43 extern struct fscache_cache *fscache_select_cache_for_object(
  44         struct fscache_cookie *);
  45
  46 /*
  47  * cookie.c
  48  */
  49 extern struct kmem_cache *fscache_cookie_jar;
  50
  51 extern void fscache_cookie_init_once(void *);
  52 extern void __fscache_cookie_put(struct fscache_cookie *);
  53
  54 /*
  55  * fsdef.c
  56  */
  57 extern struct fscache_cookie fscache_fsdef_index;
  58 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  59
  60 /*
  61  * histogram.c
  62  */
  63 #ifdef CONFIG_FSCACHE_HISTOGRAM
  64 extern atomic_t fscache_obj_instantiate_histogram[HZ];
  65 extern atomic_t fscache_objs_histogram[HZ];
  66 extern atomic_t fscache_ops_histogram[HZ];
  67 extern atomic_t fscache_retrieval_delay_histogram[HZ];
  68 extern atomic_t fscache_retrieval_histogram[HZ];
  69
  70 static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
  71 {
  72         unsigned long jif = jiffies - start_jif;
  73         if (jif >= HZ)
  74                 jif = HZ - 1;
  75         atomic_inc(&histogram[jif]);
  76 }
  77
  78 extern const struct file_operations fscache_histogram_fops;
  79
  80 #else
  81 #define fscache_hist(hist, start_jif) do {} while (0)
  82 #endif
  83
  84 /*
  85  * main.c
  86  */
  87 extern unsigned fscache_defer_lookup;
  88 extern unsigned fscache_defer_create;
  89 extern unsigned fscache_debug;
  90 extern struct kobject *fscache_root;
  91 extern struct workqueue_struct *fscache_object_wq;
  92 extern struct workqueue_struct *fscache_op_wq;
  93 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  94
  95 static inline bool fscache_object_congested(void)
  96 {
  97         return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  98 }
  99
 100 extern int fscache_wait_atomic_t(atomic_t *);
 101
 102 /*
 103  * object.c
 104  */
 105 extern void fscache_enqueue_object(struct fscache_object *);
 106
 107 /*
 108  * object-list.c
 109  */
 110 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 111 extern const struct file_operations fscache_objlist_fops;
 112
 113 extern void fscache_objlist_add(struct fscache_object *);
 114 extern void fscache_objlist_remove(struct fscache_object *);
 115 #else
 116 #define fscache_objlist_add(object) do {} while(0)
 117 #define fscache_objlist_remove(object) do {} while(0)
 118 #endif
 119
 120 /*
 121  * operation.c
 122  */
 123 extern int fscache_submit_exclusive_op(struct fscache_object *,
 124                                        struct fscache_operation *);
 125 extern int fscache_submit_op(struct fscache_object *,
 126                              struct fscache_operation *);
 127 extern int fscache_cancel_op(struct fscache_operation *, bool);
 128 extern void fscache_cancel_all_ops(struct fscache_object *);
 129 extern void fscache_abort_object(struct fscache_object *);
 130 extern void fscache_start_operations(struct fscache_object *);
 131 extern void fscache_operation_gc(struct work_struct *);
 132
 133 /*
 134  * page.c
 135  */
 136 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 137 extern int fscache_wait_for_operation_activation(struct fscache_object *,
 138                                                  struct fscache_operation *,
 139                                                  atomic_t *,
 140                                                  atomic_t *);
 141 extern void fscache_invalidate_writes(struct fscache_cookie *);
 142
 143 /*
 144  * proc.c
 145  */
 146 #ifdef CONFIG_PROC_FS
 147 extern int __init fscache_proc_init(void);
 148 extern void fscache_proc_cleanup(void);
 149 #else
 150 #define fscache_proc_init()     (0)
 151 #define fscache_proc_cleanup()  do {} while (0)
 152 #endif
 153
 154 /*
 155  * stats.c
 156  */
 157 #ifdef CONFIG_FSCACHE_STATS
 158 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 159 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 160
 161 extern atomic_t fscache_n_op_pend;
 162 extern atomic_t fscache_n_op_run;
 163 extern atomic_t fscache_n_op_enqueue;
 164 extern atomic_t fscache_n_op_deferred_release;
 165 extern atomic_t fscache_n_op_initialised;
 166 extern atomic_t fscache_n_op_release;
 167 extern atomic_t fscache_n_op_gc;
 168 extern atomic_t fscache_n_op_cancelled;
 169 extern atomic_t fscache_n_op_rejected;
 170
 171 extern atomic_t fscache_n_attr_changed;
 172 extern atomic_t fscache_n_attr_changed_ok;
 173 extern atomic_t fscache_n_attr_changed_nobufs;
 174 extern atomic_t fscache_n_attr_changed_nomem;
 175 extern atomic_t fscache_n_attr_changed_calls;
 176
 177 extern atomic_t fscache_n_allocs;
 178 extern atomic_t fscache_n_allocs_ok;
 179 extern atomic_t fscache_n_allocs_wait;
 180 extern atomic_t fscache_n_allocs_nobufs;
 181 extern atomic_t fscache_n_allocs_intr;
 182 extern atomic_t fscache_n_allocs_object_dead;
 183 extern atomic_t fscache_n_alloc_ops;
 184 extern atomic_t fscache_n_alloc_op_waits;
 185
 186 extern atomic_t fscache_n_retrievals;
 187 extern atomic_t fscache_n_retrievals_ok;
 188 extern atomic_t fscache_n_retrievals_wait;
 189 extern atomic_t fscache_n_retrievals_nodata;
 190 extern atomic_t fscache_n_retrievals_nobufs;
 191 extern atomic_t fscache_n_retrievals_intr;
 192 extern atomic_t fscache_n_retrievals_nomem;
 193 extern atomic_t fscache_n_retrievals_object_dead;
 194 extern atomic_t fscache_n_retrieval_ops;
 195 extern atomic_t fscache_n_retrieval_op_waits;
 196
 197 extern atomic_t fscache_n_stores;
 198 extern atomic_t fscache_n_stores_ok;
 199 extern atomic_t fscache_n_stores_again;
 200 extern atomic_t fscache_n_stores_nobufs;
 201 extern atomic_t fscache_n_stores_oom;
 202 extern atomic_t fscache_n_store_ops;
 203 extern atomic_t fscache_n_store_calls;
 204 extern atomic_t fscache_n_store_pages;
 205 extern atomic_t fscache_n_store_radix_deletes;
 206 extern atomic_t fscache_n_store_pages_over_limit;
 207
 208 extern atomic_t fscache_n_store_vmscan_not_storing;
 209 extern atomic_t fscache_n_store_vmscan_gone;
 210 extern atomic_t fscache_n_store_vmscan_busy;
 211 extern atomic_t fscache_n_store_vmscan_cancelled;
 212 extern atomic_t fscache_n_store_vmscan_wait;
 213
 214 extern atomic_t fscache_n_marks;
 215 extern atomic_t fscache_n_uncaches;
 216
 217 extern atomic_t fscache_n_acquires;
 218 extern atomic_t fscache_n_acquires_null;
 219 extern atomic_t fscache_n_acquires_no_cache;
 220 extern atomic_t fscache_n_acquires_ok;
 221 extern atomic_t fscache_n_acquires_nobufs;
 222 extern atomic_t fscache_n_acquires_oom;
 223
 224 extern atomic_t fscache_n_invalidates;
 225 extern atomic_t fscache_n_invalidates_run;
 226
 227 extern atomic_t fscache_n_updates;
 228 extern atomic_t fscache_n_updates_null;
 229 extern atomic_t fscache_n_updates_run;
 230
 231 extern atomic_t fscache_n_relinquishes;
 232 extern atomic_t fscache_n_relinquishes_null;
 233 extern atomic_t fscache_n_relinquishes_waitcrt;
 234 extern atomic_t fscache_n_relinquishes_retire;
 235
 236 extern atomic_t fscache_n_cookie_index;
 237 extern atomic_t fscache_n_cookie_data;
 238 extern atomic_t fscache_n_cookie_special;
 239
 240 extern atomic_t fscache_n_object_alloc;
 241 extern atomic_t fscache_n_object_no_alloc;
 242 extern atomic_t fscache_n_object_lookups;
 243 extern atomic_t fscache_n_object_lookups_negative;
 244 extern atomic_t fscache_n_object_lookups_positive;
 245 extern atomic_t fscache_n_object_lookups_timed_out;
 246 extern atomic_t fscache_n_object_created;
 247 extern atomic_t fscache_n_object_avail;
 248 extern atomic_t fscache_n_object_dead;
 249
 250 extern atomic_t fscache_n_checkaux_none;
 251 extern atomic_t fscache_n_checkaux_okay;
 252 extern atomic_t fscache_n_checkaux_update;
 253 extern atomic_t fscache_n_checkaux_obsolete;
 254
 255 extern atomic_t fscache_n_cop_alloc_object;
 256 extern atomic_t fscache_n_cop_lookup_object;
 257 extern atomic_t fscache_n_cop_lookup_complete;
 258 extern atomic_t fscache_n_cop_grab_object;
 259 extern atomic_t fscache_n_cop_invalidate_object;
 260 extern atomic_t fscache_n_cop_update_object;
 261 extern atomic_t fscache_n_cop_drop_object;
 262 extern atomic_t fscache_n_cop_put_object;
 263 extern atomic_t fscache_n_cop_sync_cache;
 264 extern atomic_t fscache_n_cop_attr_changed;
 265 extern atomic_t fscache_n_cop_read_or_alloc_page;
 266 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 267 extern atomic_t fscache_n_cop_allocate_page;
 268 extern atomic_t fscache_n_cop_allocate_pages;
 269 extern atomic_t fscache_n_cop_write_page;
 270 extern atomic_t fscache_n_cop_uncache_page;
 271 extern atomic_t fscache_n_cop_dissociate_pages;
 272
 273 extern atomic_t fscache_n_cache_no_space_reject;
 274 extern atomic_t fscache_n_cache_stale_objects;
 275 extern atomic_t fscache_n_cache_retired_objects;
 276 extern atomic_t fscache_n_cache_culled_objects;
 277
 278 static inline void fscache_stat(atomic_t *stat)
 279 {
 280         atomic_inc(stat);
 281 }
 282
 283 static inline void fscache_stat_d(atomic_t *stat)
 284 {
 285         atomic_dec(stat);
 286 }
 287
 288 #define __fscache_stat(stat) (stat)
 289
 290 extern const struct file_operations fscache_stats_fops;
 291 #else
 292
 293 #define __fscache_stat(stat) (NULL)
 294 #define fscache_stat(stat) do {} while (0)
 295 #define fscache_stat_d(stat) do {} while (0)
 296 #endif
 297
 298 /*
 299  * raise an event on an object
 300  * - if the event is not masked for that object, then the object is
 301  *   queued for attention by the thread pool.
 302  */
 303 static inline void fscache_raise_event(struct fscache_object *object,
 304                                        unsigned event)
 305 {
 306         BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 307 #if 0
 308         printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
 309                object->debug_id, object->event_mask, (1 << event));
 310 #endif
 311         if (!test_and_set_bit(event, &object->events) &&
 312             test_bit(event, &object->event_mask))
 313                 fscache_enqueue_object(object);
 314 }
 315
 316 /*
 317  * drop a reference to a cookie
 318  */
 319 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 320 {
 321         BUG_ON(atomic_read(&cookie->usage) <= 0);
 322         if (atomic_dec_and_test(&cookie->usage))
 323                 __fscache_cookie_put(cookie);
 324 }
 325
 326 /*
 327  * get an extra reference to a netfs retrieval context
 328  */
 329 static inline
 330 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 331 {
 332         if (cookie->def->get_context)
 333                 cookie->def->get_context(cookie->netfs_data, context);
 334         return context;
 335 }
 336
 337 /*
 338  * release a reference to a netfs retrieval context
 339  */
 340 static inline
 341 void fscache_put_context(struct fscache_cookie *cookie, void *context)
 342 {
 343         if (cookie->def->put_context)
 344                 cookie->def->put_context(cookie->netfs_data, context);
 345 }
 346
 347 /*****************************************************************************/
 348 /*
 349  * debug tracing
 350  */
 351 #define dbgprintk(FMT, ...) \
 352         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 353
 354 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 355 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 356 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 357
 358 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 359
 360 #ifdef __KDEBUG
 361 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 362 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 363 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 364
 365 #elif defined(CONFIG_FSCACHE_DEBUG)
 366 #define _enter(FMT, ...)                        \
 367 do {                                            \
 368         if (__do_kdebug(ENTER))                 \
 369                 kenter(FMT, ##__VA_ARGS__);     \
 370 } while (0)
 371
 372 #define _leave(FMT, ...)                        \
 373 do {                                            \
 374         if (__do_kdebug(LEAVE))                 \
 375                 kleave(FMT, ##__VA_ARGS__);     \
 376 } while (0)
 377
 378 #define _debug(FMT, ...)                        \
 379 do {                                            \
 380         if (__do_kdebug(DEBUG))                 \
 381                 kdebug(FMT, ##__VA_ARGS__);     \
 382 } while (0)
 383
 384 #else
 385 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 386 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 387 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 388 #endif
 389
 390 /*
 391  * determine whether a particular optional debugging point should be logged
 392  * - we need to go through three steps to persuade cpp to correctly join the
 393  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 394  */
 395 #define ____do_kdebug(LEVEL, POINT) \
 396         unlikely((fscache_debug & \
 397                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 398 #define ___do_kdebug(LEVEL, POINT) \
 399         ____do_kdebug(LEVEL, POINT)
 400 #define __do_kdebug(POINT) \
 401         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 402
 403 #define FSCACHE_DEBUG_CACHE     0
 404 #define FSCACHE_DEBUG_COOKIE    1
 405 #define FSCACHE_DEBUG_PAGE      2
 406 #define FSCACHE_DEBUG_OPERATION 3
 407
 408 #define FSCACHE_POINT_ENTER     1
 409 #define FSCACHE_POINT_LEAVE     2
 410 #define FSCACHE_POINT_DEBUG     4
 411
 412 #ifndef FSCACHE_DEBUG_LEVEL
 413 #define FSCACHE_DEBUG_LEVEL CACHE
 414 #endif
 415
 416 /*
 417  * assertions
 418  */
 419 #if 1 /* defined(__KDEBUGALL) */
 420
 421 #define ASSERT(X)                                                       \
 422 do {                                                                    \
 423         if (unlikely(!(X))) {                                           \
 424                 pr_err("\n");                                   \
 425                 pr_err("Assertion failed\n");   \
 426                 BUG();                                                  \
 427         }                                                               \
 428 } while (0)
 429
 430 #define ASSERTCMP(X, OP, Y)                                             \
 431 do {                                                                    \
 432         if (unlikely(!((X) OP (Y)))) {                                  \
 433                 pr_err("\n");                                   \
 434                 pr_err("Assertion failed\n");   \
 435                 pr_err("%lx " #OP " %lx is false\n",            \
 436                        (unsigned long)(X), (unsigned long)(Y));         \
 437                 BUG();                                                  \
 438         }                                                               \
 439 } while (0)
 440
 441 #define ASSERTIF(C, X)                                                  \
 442 do {                                                                    \
 443         if (unlikely((C) && !(X))) {                                    \
 444                 pr_err("\n");                                   \
 445                 pr_err("Assertion failed\n");   \
 446                 BUG();                                                  \
 447         }                                                               \
 448 } while (0)
 449
 450 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 451 do {                                                                    \
 452         if (unlikely((C) && !((X) OP (Y)))) {                           \
 453                 pr_err("\n");                                   \
 454                 pr_err("Assertion failed\n");   \
 455                 pr_err("%lx " #OP " %lx is false\n",            \
 456                        (unsigned long)(X), (unsigned long)(Y));         \
 457                 BUG();                                                  \
 458         }                                                               \
 459 } while (0)
 460
 461 #else
 462
 463 #define ASSERT(X)                       do {} while (0)
 464 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 465 #define ASSERTIF(C, X)                  do {} while (0)
 466 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 467
 468 #endif /* assert or not */