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