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-main.c
  32  */
  33 extern unsigned fscache_defer_lookup;
  34 extern unsigned fscache_defer_create;
  35 extern unsigned fscache_debug;
  36 extern struct kobject *fscache_root;
  37
  38 /*****************************************************************************/
  39 /*
  40  * debug tracing
  41  */
  42 #define dbgprintk(FMT, ...) \
  43         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
  44
  45 /* make sure we maintain the format strings, even when debugging is disabled */
  46 static inline __attribute__((format(printf, 1, 2)))
  47 void _dbprintk(const char *fmt, ...)
  48 {
  49 }
  50
  51 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
  52 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
  53 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
  54
  55 #define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
  56
  57 #ifdef __KDEBUG
  58 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
  59 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
  60 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
  61
  62 #elif defined(CONFIG_FSCACHE_DEBUG)
  63 #define _enter(FMT, ...)                        \
  64 do {                                            \
  65         if (__do_kdebug(ENTER))                 \
  66                 kenter(FMT, ##__VA_ARGS__);     \
  67 } while (0)
  68
  69 #define _leave(FMT, ...)                        \
  70 do {                                            \
  71         if (__do_kdebug(LEAVE))                 \
  72                 kleave(FMT, ##__VA_ARGS__);     \
  73 } while (0)
  74
  75 #define _debug(FMT, ...)                        \
  76 do {                                            \
  77         if (__do_kdebug(DEBUG))                 \
  78                 kdebug(FMT, ##__VA_ARGS__);     \
  79 } while (0)
  80
  81 #else
  82 #define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
  83 #define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
  84 #define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
  85 #endif
  86
  87 /*
  88  * determine whether a particular optional debugging point should be logged
  89  * - we need to go through three steps to persuade cpp to correctly join the
  90  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
  91  */
  92 #define ____do_kdebug(LEVEL, POINT) \
  93         unlikely((fscache_debug & \
  94                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
  95 #define ___do_kdebug(LEVEL, POINT) \
  96         ____do_kdebug(LEVEL, POINT)
  97 #define __do_kdebug(POINT) \
  98         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
  99
 100 #define FSCACHE_DEBUG_CACHE     0
 101 #define FSCACHE_DEBUG_COOKIE    1
 102 #define FSCACHE_DEBUG_PAGE      2
 103 #define FSCACHE_DEBUG_OPERATION 3
 104
 105 #define FSCACHE_POINT_ENTER     1
 106 #define FSCACHE_POINT_LEAVE     2
 107 #define FSCACHE_POINT_DEBUG     4
 108
 109 #ifndef FSCACHE_DEBUG_LEVEL
 110 #define FSCACHE_DEBUG_LEVEL CACHE
 111 #endif
 112
 113 /*
 114  * assertions
 115  */
 116 #if 1 /* defined(__KDEBUGALL) */
 117
 118 #define ASSERT(X)                                                       \
 119 do {                                                                    \
 120         if (unlikely(!(X))) {                                           \
 121                 printk(KERN_ERR "\n");                                  \
 122                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 123                 BUG();                                                  \
 124         }                                                               \
 125 } while (0)
 126
 127 #define ASSERTCMP(X, OP, Y)                                             \
 128 do {                                                                    \
 129         if (unlikely(!((X) OP (Y)))) {                                  \
 130                 printk(KERN_ERR "\n");                                  \
 131                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 132                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 133                        (unsigned long)(X), (unsigned long)(Y));         \
 134                 BUG();                                                  \
 135         }                                                               \
 136 } while (0)
 137
 138 #define ASSERTIF(C, X)                                                  \
 139 do {                                                                    \
 140         if (unlikely((C) && !(X))) {                                    \
 141                 printk(KERN_ERR "\n");                                  \
 142                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 143                 BUG();                                                  \
 144         }                                                               \
 145 } while (0)
 146
 147 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 148 do {                                                                    \
 149         if (unlikely((C) && !((X) OP (Y)))) {                           \
 150                 printk(KERN_ERR "\n");                                  \
 151                 printk(KERN_ERR "FS-Cache: Assertion failed\n");        \
 152                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 153                        (unsigned long)(X), (unsigned long)(Y));         \
 154                 BUG();                                                  \
 155         }                                                               \
 156 } while (0)
 157
 158 #else
 159
 160 #define ASSERT(X)                       do {} while (0)
 161 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 162 #define ASSERTIF(C, X)                  do {} while (0)
 163 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 164
 165 #endif /* assert or not */