fs/ocfs2/cluster/masklog.h

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * Copyright (C) 2005 Oracle.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public
  17  * License along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA.
  20  */
  21
  22 #ifndef O2CLUSTER_MASKLOG_H
  23 #define O2CLUSTER_MASKLOG_H
  24
  25 /*
  26  * For now this is a trivial wrapper around printk() that gives the critical
  27  * ability to enable sets of debugging output at run-time.  In the future this
  28  * will almost certainly be redirected to relayfs so that it can pay a
  29  * substantially lower heisenberg tax.
  30  *
  31  * Callers associate the message with a bitmask and a global bitmask is
  32  * maintained with help from /proc.  If any of the bits match the message is
  33  * output.
  34  *
  35  * We must have efficient bit tests on i386 and it seems gcc still emits crazy
  36  * code for the 64bit compare.  It emits very good code for the dual unsigned
  37  * long tests, though, completely avoiding tests that can never pass if the
  38  * caller gives a constant bitmask that fills one of the longs with all 0s.  So
  39  * the desire is to have almost all of the calls decided on by comparing just
  40  * one of the longs.  This leads to having infrequently given bits that are
  41  * frequently matched in the high bits.
  42  *
  43  * _ERROR and _NOTICE are used for messages that always go to the console and
  44  * have appropriate KERN_ prefixes.  We wrap these in our function instead of
  45  * just calling printk() so that this can eventually make its way through
  46  * relayfs along with the debugging messages.  Everything else gets KERN_DEBUG.
  47  * The inline tests and macro dance give GCC the opportunity to quite cleverly
  48  * only emit the appropriage printk() when the caller passes in a constant
  49  * mask, as is almost always the case.
  50  *
  51  * All this bitmask nonsense is managed from the files under
  52  * /sys/fs/o2cb/logmask/.  Reading the files gives a straightforward
  53  * indication of which bits are allowed (allow) or denied (off/deny).
  54  *      ENTRY deny
  55  *      EXIT deny
  56  *      TCP off
  57  *      MSG off
  58  *      SOCKET off
  59  *      ERROR allow
  60  *      NOTICE allow
  61  *
  62  * Writing changes the state of a given bit and requires a strictly formatted
  63  * single write() call:
  64  *
  65  *      write(fd, "allow", 5);
  66  *
  67  * Echoing allow/deny/off string into the logmask files can flip the bits
  68  * on or off as expected; here is the bash script for example:
  69  *
  70  * log_mask="/sys/fs/o2cb/log_mask"
  71  * for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do
  72  *      echo allow >"$log_mask"/"$node"
  73  * done
  74  *
  75  * The debugfs.ocfs2 tool can also flip the bits with the -l option:
  76  *
  77  * debugfs.ocfs2 -l TCP allow
  78  */
  79
  80 /* for task_struct */
  81 #include <linux/sched.h>
  82
  83 /* bits that are frequently given and infrequently matched in the low word */
  84 /* NOTE: If you add a flag, you need to also update mlog.c! */
  85 #define ML_ENTRY        0x0000000000000001ULL /* func call entry */
  86 #define ML_EXIT         0x0000000000000002ULL /* func call exit */
  87 #define ML_TCP          0x0000000000000004ULL /* net cluster/tcp.c */
  88 #define ML_MSG          0x0000000000000008ULL /* net network messages */
  89 #define ML_SOCKET       0x0000000000000010ULL /* net socket lifetime */
  90 #define ML_HEARTBEAT    0x0000000000000020ULL /* hb all heartbeat tracking */
  91 #define ML_HB_BIO       0x0000000000000040ULL /* hb io tracing */
  92 #define ML_DLMFS        0x0000000000000080ULL /* dlm user dlmfs */
  93 #define ML_DLM          0x0000000000000100ULL /* dlm general debugging */
  94 #define ML_DLM_DOMAIN   0x0000000000000200ULL /* dlm domain debugging */
  95 #define ML_DLM_THREAD   0x0000000000000400ULL /* dlm domain thread */
  96 #define ML_DLM_MASTER   0x0000000000000800ULL /* dlm master functions */
  97 #define ML_DLM_RECOVERY 0x0000000000001000ULL /* dlm master functions */
  98 #define ML_AIO          0x0000000000002000ULL /* ocfs2 aio read and write */
  99 #define ML_JOURNAL      0x0000000000004000ULL /* ocfs2 journalling functions */
 100 #define ML_DISK_ALLOC   0x0000000000008000ULL /* ocfs2 disk allocation */
 101 #define ML_SUPER        0x0000000000010000ULL /* ocfs2 mount / umount */
 102 #define ML_FILE_IO      0x0000000000020000ULL /* ocfs2 file I/O */
 103 #define ML_EXTENT_MAP   0x0000000000040000ULL /* ocfs2 extent map caching */
 104 #define ML_DLM_GLUE     0x0000000000080000ULL /* ocfs2 dlm glue layer */
 105 #define ML_BH_IO        0x0000000000100000ULL /* ocfs2 buffer I/O */
 106 #define ML_UPTODATE     0x0000000000200000ULL /* ocfs2 caching sequence #'s */
 107 #define ML_NAMEI        0x0000000000400000ULL /* ocfs2 directory / namespace */
 108 #define ML_INODE        0x0000000000800000ULL /* ocfs2 inode manipulation */
 109 #define ML_VOTE         0x0000000001000000ULL /* ocfs2 node messaging  */
 110 #define ML_DCACHE       0x0000000002000000ULL /* ocfs2 dcache operations */
 111 #define ML_CONN         0x0000000004000000ULL /* net connection management */
 112 #define ML_QUORUM       0x0000000008000000ULL /* net connection quorum */
 113 #define ML_EXPORT       0x0000000010000000ULL /* ocfs2 export operations */
 114 #define ML_XATTR        0x0000000020000000ULL /* ocfs2 extended attributes */
 115 #define ML_QUOTA        0x0000000040000000ULL /* ocfs2 quota operations */
 116 #define ML_REFCOUNT     0x0000000080000000ULL /* refcount tree operations */
 117 /* bits that are infrequently given and frequently matched in the high word */
 118 #define ML_ERROR        0x0000000100000000ULL /* sent to KERN_ERR */
 119 #define ML_NOTICE       0x0000000200000000ULL /* setn to KERN_NOTICE */
 120 #define ML_KTHREAD      0x0000000400000000ULL /* kernel thread activity */
 121
 122 #define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
 123 #define MLOG_INITIAL_NOT_MASK (ML_ENTRY|ML_EXIT)
 124 #ifndef MLOG_MASK_PREFIX
 125 #define MLOG_MASK_PREFIX 0
 126 #endif
 127
 128 /*
 129  * When logging is disabled, force the bit test to 0 for anything other
 130  * than errors and notices, allowing gcc to remove the code completely.
 131  * When enabled, allow all masks.
 132  */
 133 #if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
 134 #define ML_ALLOWED_BITS ~0
 135 #else
 136 #define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
 137 #endif
 138
 139 #define MLOG_MAX_BITS 64
 140
 141 struct mlog_bits {
 142         unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG];
 143 };
 144
 145 extern struct mlog_bits mlog_and_bits, mlog_not_bits;
 146
 147 #if BITS_PER_LONG == 32
 148
 149 #define __mlog_test_u64(mask, bits)                     \
 150         ( (u32)(mask & 0xffffffff) & bits.words[0] ||   \
 151           ((u64)(mask) >> 32) & bits.words[1] )
 152 #define __mlog_set_u64(mask, bits) do {                 \
 153         bits.words[0] |= (u32)(mask & 0xffffffff);      \
 154         bits.words[1] |= (u64)(mask) >> 32;             \
 155 } while (0)
 156 #define __mlog_clear_u64(mask, bits) do {               \
 157         bits.words[0] &= ~((u32)(mask & 0xffffffff));   \
 158         bits.words[1] &= ~((u64)(mask) >> 32);          \
 159 } while (0)
 160 #define MLOG_BITS_RHS(mask) {                           \
 161         {                                               \
 162                 [0] = (u32)(mask & 0xffffffff),         \
 163                 [1] = (u64)(mask) >> 32,                \
 164         }                                               \
 165 }
 166
 167 #else /* 32bit long above, 64bit long below */
 168
 169 #define __mlog_test_u64(mask, bits)     ((mask) & bits.words[0])
 170 #define __mlog_set_u64(mask, bits) do {         \
 171         bits.words[0] |= (mask);                \
 172 } while (0)
 173 #define __mlog_clear_u64(mask, bits) do {       \
 174         bits.words[0] &= ~(mask);               \
 175 } while (0)
 176 #define MLOG_BITS_RHS(mask) { { (mask) } }
 177
 178 #endif
 179
 180 /*
 181  * smp_processor_id() "helpfully" screams when called outside preemptible
 182  * regions in current kernels.  sles doesn't have the variants that don't
 183  * scream.  just do this instead of trying to guess which we're building
 184  * against.. *sigh*.
 185  */
 186 #define __mlog_cpu_guess ({             \
 187         unsigned long _cpu = get_cpu(); \
 188         put_cpu();                      \
 189         _cpu;                           \
 190 })
 191
 192 /* In the following two macros, the whitespace after the ',' just
 193  * before ##args is intentional. Otherwise, gcc 2.95 will eat the
 194  * previous token if args expands to nothing.
 195  */
 196 #define __mlog_printk(level, fmt, args...)                              \
 197         printk(level "(%u,%lu):%s:%d " fmt, task_pid_nr(current),       \
 198                __mlog_cpu_guess, __PRETTY_FUNCTION__, __LINE__ ,        \
 199                ##args)
 200
 201 #define mlog(mask, fmt, args...) do {                                   \
 202         u64 __m = MLOG_MASK_PREFIX | (mask);                            \
 203         if ((__m & ML_ALLOWED_BITS) &&                                  \
 204             __mlog_test_u64(__m, mlog_and_bits) &&                      \
 205             !__mlog_test_u64(__m, mlog_not_bits)) {                     \
 206                 if (__m & ML_ERROR)                                     \
 207                         __mlog_printk(KERN_ERR, "ERROR: "fmt , ##args); \
 208                 else if (__m & ML_NOTICE)                               \
 209                         __mlog_printk(KERN_NOTICE, fmt , ##args);       \
 210                 else __mlog_printk(KERN_INFO, fmt , ##args);            \
 211         }                                                               \
 212 } while (0)
 213
 214 #define mlog_errno(st) do {                                             \
 215         int _st = (st);                                                 \
 216         if (_st != -ERESTARTSYS && _st != -EINTR &&                     \
 217             _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC)                \
 218                 mlog(ML_ERROR, "status = %lld\n", (long long)_st);      \
 219 } while (0)
 220
 221 #if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
 222 #define mlog_entry(fmt, args...) do {                                   \
 223         mlog(ML_ENTRY, "ENTRY:" fmt , ##args);                          \
 224 } while (0)
 225
 226 #define mlog_entry_void() do {                                          \
 227         mlog(ML_ENTRY, "ENTRY:\n");                                     \
 228 } while (0)
 229
 230 /*
 231  * We disable this for sparse.
 232  */
 233 #if !defined(__CHECKER__)
 234 #define mlog_exit(st) do {                                                   \
 235         if (__builtin_types_compatible_p(typeof(st), unsigned long))         \
 236                 mlog(ML_EXIT, "EXIT: %lu\n", (unsigned long) (st));          \
 237         else if (__builtin_types_compatible_p(typeof(st), signed long))      \
 238                 mlog(ML_EXIT, "EXIT: %ld\n", (signed long) (st));            \
 239         else if (__builtin_types_compatible_p(typeof(st), unsigned int)      \
 240                  || __builtin_types_compatible_p(typeof(st), unsigned short) \
 241                  || __builtin_types_compatible_p(typeof(st), unsigned char)) \
 242                 mlog(ML_EXIT, "EXIT: %u\n", (unsigned int) (st));            \
 243         else if (__builtin_types_compatible_p(typeof(st), signed int)        \
 244                  || __builtin_types_compatible_p(typeof(st), signed short)   \
 245                  || __builtin_types_compatible_p(typeof(st), signed char))   \
 246                 mlog(ML_EXIT, "EXIT: %d\n", (signed int) (st));              \
 247         else if (__builtin_types_compatible_p(typeof(st), long long))        \
 248                 mlog(ML_EXIT, "EXIT: %lld\n", (long long) (st));             \
 249         else                                                                 \
 250                 mlog(ML_EXIT, "EXIT: %llu\n", (unsigned long long) (st));    \
 251 } while (0)
 252 #else
 253 #define mlog_exit(st) do {                                                   \
 254         mlog(ML_EXIT, "EXIT: %lld\n", (long long) (st));                     \
 255 } while (0)
 256 #endif
 257
 258 #define mlog_exit_ptr(ptr) do {                                         \
 259         mlog(ML_EXIT, "EXIT: %p\n", ptr);                               \
 260 } while (0)
 261
 262 #define mlog_exit_void() do {                                           \
 263         mlog(ML_EXIT, "EXIT\n");                                        \
 264 } while (0)
 265 #else
 266 #define mlog_entry(...)  do { } while (0)
 267 #define mlog_entry_void(...)  do { } while (0)
 268 #define mlog_exit(...)  do { } while (0)
 269 #define mlog_exit_ptr(...)  do { } while (0)
 270 #define mlog_exit_void(...)  do { } while (0)
 271 #endif  /* defined(CONFIG_OCFS2_DEBUG_MASKLOG) */
 272
 273 #define mlog_bug_on_msg(cond, fmt, args...) do {                        \
 274         if (cond) {                                                     \
 275                 mlog(ML_ERROR, "bug expression: " #cond "\n");          \
 276                 mlog(ML_ERROR, fmt, ##args);                            \
 277                 BUG();                                                  \
 278         }                                                               \
 279 } while (0)
 280
 281 #include <linux/kobject.h>
 282 #include <linux/sysfs.h>
 283 int mlog_sys_init(struct kset *o2cb_subsys);
 284 void mlog_sys_shutdown(void);
 285
 286 #endif /* O2CLUSTER_MASKLOG_H */