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  * fsc-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  * fsc-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  * fsc-fsdef.c
  49  */
  50 extern struct fscache_cookie fscache_fsdef_index;
  51 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  52
  53 /*
  54  * fsc-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  * fsc-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  * fsc-object.c
  90  */
  91 extern void fscache_withdrawing_object(struct fscache_cache *,
  92                                        struct fscache_object *);
  93 extern void fscache_enqueue_object(struct fscache_object *);
  94
  95 /*
  96  * fsc-operation.c
  97  */
  98 #define fscache_start_operations(obj) BUG()
  99
 100 /*
 101  * fsc-proc.c
 102  */
 103 #ifdef CONFIG_PROC_FS
 104 extern int __init fscache_proc_init(void);
 105 extern void fscache_proc_cleanup(void);
 106 #else
 107 #define fscache_proc_init()     (0)
 108 #define fscache_proc_cleanup()  do {} while (0)
 109 #endif
 110
 111 /*
 112  * fsc-stats.c
 113  */
 114 #ifdef CONFIG_FSCACHE_STATS
 115 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 116 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 117
 118 extern atomic_t fscache_n_op_pend;
 119 extern atomic_t fscache_n_op_run;
 120 extern atomic_t fscache_n_op_enqueue;
 121 extern atomic_t fscache_n_op_deferred_release;
 122 extern atomic_t fscache_n_op_release;
 123 extern atomic_t fscache_n_op_gc;
 124
 125 extern atomic_t fscache_n_attr_changed;
 126 extern atomic_t fscache_n_attr_changed_ok;
 127 extern atomic_t fscache_n_attr_changed_nobufs;
 128 extern atomic_t fscache_n_attr_changed_nomem;
 129 extern atomic_t fscache_n_attr_changed_calls;
 130
 131 extern atomic_t fscache_n_allocs;
 132 extern atomic_t fscache_n_allocs_ok;
 133 extern atomic_t fscache_n_allocs_wait;
 134 extern atomic_t fscache_n_allocs_nobufs;
 135 extern atomic_t fscache_n_alloc_ops;
 136 extern atomic_t fscache_n_alloc_op_waits;
 137
 138 extern atomic_t fscache_n_retrievals;
 139 extern atomic_t fscache_n_retrievals_ok;
 140 extern atomic_t fscache_n_retrievals_wait;
 141 extern atomic_t fscache_n_retrievals_nodata;
 142 extern atomic_t fscache_n_retrievals_nobufs;
 143 extern atomic_t fscache_n_retrievals_intr;
 144 extern atomic_t fscache_n_retrievals_nomem;
 145 extern atomic_t fscache_n_retrieval_ops;
 146 extern atomic_t fscache_n_retrieval_op_waits;
 147
 148 extern atomic_t fscache_n_stores;
 149 extern atomic_t fscache_n_stores_ok;
 150 extern atomic_t fscache_n_stores_again;
 151 extern atomic_t fscache_n_stores_nobufs;
 152 extern atomic_t fscache_n_stores_oom;
 153 extern atomic_t fscache_n_store_ops;
 154 extern atomic_t fscache_n_store_calls;
 155
 156 extern atomic_t fscache_n_marks;
 157 extern atomic_t fscache_n_uncaches;
 158
 159 extern atomic_t fscache_n_acquires;
 160 extern atomic_t fscache_n_acquires_null;
 161 extern atomic_t fscache_n_acquires_no_cache;
 162 extern atomic_t fscache_n_acquires_ok;
 163 extern atomic_t fscache_n_acquires_nobufs;
 164 extern atomic_t fscache_n_acquires_oom;
 165
 166 extern atomic_t fscache_n_updates;
 167 extern atomic_t fscache_n_updates_null;
 168 extern atomic_t fscache_n_updates_run;
 169
 170 extern atomic_t fscache_n_relinquishes;
 171 extern atomic_t fscache_n_relinquishes_null;
 172 extern atomic_t fscache_n_relinquishes_waitcrt;
 173
 174 extern atomic_t fscache_n_cookie_index;
 175 extern atomic_t fscache_n_cookie_data;
 176 extern atomic_t fscache_n_cookie_special;
 177
 178 extern atomic_t fscache_n_object_alloc;
 179 extern atomic_t fscache_n_object_no_alloc;
 180 extern atomic_t fscache_n_object_lookups;
 181 extern atomic_t fscache_n_object_lookups_negative;
 182 extern atomic_t fscache_n_object_lookups_positive;
 183 extern atomic_t fscache_n_object_created;
 184 extern atomic_t fscache_n_object_avail;
 185 extern atomic_t fscache_n_object_dead;
 186
 187 extern atomic_t fscache_n_checkaux_none;
 188 extern atomic_t fscache_n_checkaux_okay;
 189 extern atomic_t fscache_n_checkaux_update;
 190 extern atomic_t fscache_n_checkaux_obsolete;
 191
 192 static inline void fscache_stat(atomic_t *stat)
 193 {
 194         atomic_inc(stat);
 195 }
 196
 197 extern const struct file_operations fscache_stats_fops;
 198 #else
 199
 200 #define fscache_stat(stat) do {} while (0)
 201 #endif
 202
 203 /*
 204  * raise an event on an object
 205  * - if the event is not masked for that object, then the object is
 206  *   queued for attention by the thread pool.
 207  */
 208 static inline void fscache_raise_event(struct fscache_object *object,
 209                                        unsigned event)
 210 {
 211         if (!test_and_set_bit(event, &object->events) &&
 212             test_bit(event, &object->event_mask))
 213                 fscache_enqueue_object(object);
 214 }
 215
 216 /*
 217  * drop a reference to a cookie
 218  */
 219 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 220 {
 221         BUG_ON(atomic_read(&cookie->usage) <= 0);
 222         if (atomic_dec_and_test(&cookie->usage))
 223                 __fscache_cookie_put(cookie);
 224 }
 225
 226 /*****************************************************************************/
 227 /*
 228  * debug tracing
 229  */
 230 #define dbgprintk(FMT, ...) \
 231         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 232
 233 /* make sure we maintain the format strings, even when debugging is disabled */
 234 static inline __attribute__((format(printf, 1, 2)))
 235 void _dbprintk(const char *fmt, ...)
 236 {
 237 }
 238
 239 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 240 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 241 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 242
 243 #define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
 244
 245 #ifdef __KDEBUG
 246 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 247 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 248 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 249
 250 #elif defined(CONFIG_FSCACHE_DEBUG)
 251 #define _enter(FMT, ...)                        \
 252 do {                                            \
 253         if (__do_kdebug(ENTER))                 \
 254                 kenter(FMT, ##__VA_ARGS__);     \
 255 } while (0)
 256
 257 #define _leave(FMT, ...)                        \
 258 do {                                            \
 259         if (__do_kdebug(LEAVE))                 \
 260                 kleave(FMT, ##__VA_ARGS__);     \
 261 } while (0)
 262
 263 #define _debug(FMT, ...)                        \
 264 do {                                            \
 265         if (__do_kdebug(DEBUG))                 \
 266                 kdebug(FMT, ##__VA_ARGS__);     \
 267 } while (0)
 268
 269 #else
 270 #define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 271 #define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 272 #define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
 273 #endif
 274
 275 /*
 276  * determine whether a particular optional debugging point should be logged
 277  * - we need to go through three steps to persuade cpp to correctly join the
 278  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 279  */
 280 #define ____do_kdebug(LEVEL, POINT) \
 281         unlikely((fscache_debug & \
 282                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 283 #define ___do_kdebug(LEVEL, POINT) \
 284         ____do_kdebug(LEVEL, POINT)
 285 #define __do_kdebug(POINT) \
 286         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 287
 288 #define FSCACHE_DEBUG_CACHE     0
 289 #define FSCACHE_DEBUG_COOKIE    1
 290 #define FSCACHE_DEBUG_PAGE      2
 291 #define FSCACHE_DEBUG_OPERATION 3
 292
 293 #define FSCACHE_POINT_ENTER     1
 294 #define FSCACHE_POINT_LEAVE     2
 295 #define FSCACHE_POINT_DEBUG     4
 296
 297 #ifndef FSCACHE_DEBUG_LEVEL
 298 #define FSCACHE_DEBUG_LEVEL CACHE
 299 #endif
 300
 301 /*
 302  * assertions
 303  */
 304 #if 1 /* defined(__KDEBUGALL) */
 305
 306 #define ASSERT(X)                                                       \
 307 do {                                                                    \
 308         if (unlikely(!(X))) {                                           \
 309                 printk(KERN_ERR "\n");                                  \
 310                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 311                 BUG();                                                  \
 312         }                                                               \
 313 } while (0)
 314
 315 #define ASSERTCMP(X, OP, Y)                                             \
 316 do {                                                                    \
 317         if (unlikely(!((X) OP (Y)))) {                                  \
 318                 printk(KERN_ERR "\n");                                  \
 319                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 320                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 321                        (unsigned long)(X), (unsigned long)(Y));         \
 322                 BUG();                                                  \
 323         }                                                               \
 324 } while (0)
 325
 326 #define ASSERTIF(C, X)                                                  \
 327 do {                                                                    \
 328         if (unlikely((C) && !(X))) {                                    \
 329                 printk(KERN_ERR "\n");                                  \
 330                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 331                 BUG();                                                  \
 332         }                                                               \
 333 } while (0)
 334
 335 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 336 do {                                                                    \
 337         if (unlikely((C) && !((X) OP (Y)))) {                           \
 338                 printk(KERN_ERR "\n");                                  \
 339                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 340                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 341                        (unsigned long)(X), (unsigned long)(Y));         \
 342                 BUG();                                                  \
 343         }                                                               \
 344 } while (0)
 345
 346 #else
 347
 348 #define ASSERT(X)                       do {} while (0)
 349 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 350 #define ASSERTIF(C, X)                  do {} while (0)
 351 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 352
 353 #endif /* assert or not */