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 masklog.c! */ 85 #define ML_TCP 0x0000000000000001ULL /* net cluster/tcp.c */ 86 #define ML_MSG 0x0000000000000002ULL /* net network messages */ 87 #define ML_SOCKET 0x0000000000000004ULL /* net socket lifetime */ 88 #define ML_HEARTBEAT 0x0000000000000008ULL /* hb all heartbeat tracking */ 89 #define ML_HB_BIO 0x0000000000000010ULL /* hb io tracing */ 90 #define ML_DLMFS 0x0000000000000020ULL /* dlm user dlmfs */ 91 #define ML_DLM 0x0000000000000040ULL /* dlm general debugging */ 92 #define ML_DLM_DOMAIN 0x0000000000000080ULL /* dlm domain debugging */ 93 #define ML_DLM_THREAD 0x0000000000000100ULL /* dlm domain thread */ 94 #define ML_DLM_MASTER 0x0000000000000200ULL /* dlm master functions */ 95 #define ML_DLM_RECOVERY 0x0000000000000400ULL /* dlm master functions */ 96 #define ML_DLM_GLUE 0x0000000000000800ULL /* ocfs2 dlm glue layer */ 97 #define ML_VOTE 0x0000000000001000ULL /* ocfs2 node messaging */ 98 #define ML_CONN 0x0000000000002000ULL /* net connection management */ 99 #define ML_QUORUM 0x0000000000004000ULL /* net connection quorum */ 100 #define ML_BASTS 0x0000000000008000ULL /* dlmglue asts and basts */ 101 #define ML_CLUSTER 0x0000000000010000ULL /* cluster stack */ 102 103 /* bits that are infrequently given and frequently matched in the high word */ 104 #define ML_ERROR 0x1000000000000000ULL /* sent to KERN_ERR */ 105 #define ML_NOTICE 0x2000000000000000ULL /* setn to KERN_NOTICE */ 106 #define ML_KTHREAD 0x4000000000000000ULL /* kernel thread activity */ 107 108 #define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE) 109 #ifndef MLOG_MASK_PREFIX 110 #define MLOG_MASK_PREFIX 0 111 #endif 112 113 /* 114 * When logging is disabled, force the bit test to 0 for anything other 115 * than errors and notices, allowing gcc to remove the code completely. 116 * When enabled, allow all masks. 117 */ 118 #if defined(CONFIG_OCFS2_DEBUG_MASKLOG) 119 #define ML_ALLOWED_BITS ~0 120 #else 121 #define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE) 122 #endif 123 124 #define MLOG_MAX_BITS 64 125 126 struct mlog_bits { 127 unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG]; 128 }; 129 130 extern struct mlog_bits mlog_and_bits, mlog_not_bits; 131 132 #if BITS_PER_LONG == 32 133 134 #define __mlog_test_u64(mask, bits) \ 135 ( (u32)(mask & 0xffffffff) & bits.words[0] || \ 136 ((u64)(mask) >> 32) & bits.words[1] ) 137 #define __mlog_set_u64(mask, bits) do { \ 138 bits.words[0] |= (u32)(mask & 0xffffffff); \ 139 bits.words[1] |= (u64)(mask) >> 32; \ 140 } while (0) 141 #define __mlog_clear_u64(mask, bits) do { \ 142 bits.words[0] &= ~((u32)(mask & 0xffffffff)); \ 143 bits.words[1] &= ~((u64)(mask) >> 32); \ 144 } while (0) 145 #define MLOG_BITS_RHS(mask) { \ 146 { \ 147 [0] = (u32)(mask & 0xffffffff), \ 148 [1] = (u64)(mask) >> 32, \ 149 } \ 150 } 151 152 #else /* 32bit long above, 64bit long below */ 153 154 #define __mlog_test_u64(mask, bits) ((mask) & bits.words[0]) 155 #define __mlog_set_u64(mask, bits) do { \ 156 bits.words[0] |= (mask); \ 157 } while (0) 158 #define __mlog_clear_u64(mask, bits) do { \ 159 bits.words[0] &= ~(mask); \ 160 } while (0) 161 #define MLOG_BITS_RHS(mask) { { (mask) } } 162 163 #endif 164 165 __printf(4, 5) 166 void __mlog_printk(const u64 *m, const char *func, int line, 167 const char *fmt, ...); 168 169 /* 170 * Testing before the __mlog_printk call lets the compiler eliminate the 171 * call completely when (m & ML_ALLOWED_BITS) is 0. 172 */ 173 #define mlog(mask, fmt, ...) \ 174 do { \ 175 u64 _m = MLOG_MASK_PREFIX | (mask); \ 176 if (_m & ML_ALLOWED_BITS) \ 177 __mlog_printk(&_m, __func__, __LINE__, fmt, \ 178 ##__VA_ARGS__); \ 179 } while (0) 180 181 #define mlog_errno(st) ({ \ 182 int _st = (st); \ 183 if (_st != -ERESTARTSYS && _st != -EINTR && \ 184 _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC && \ 185 _st != -EDQUOT) \ 186 mlog(ML_ERROR, "status = %lld\n", (long long)_st); \ 187 _st; \ 188 }) 189 190 #define mlog_bug_on_msg(cond, fmt, args...) do { \ 191 if (cond) { \ 192 mlog(ML_ERROR, "bug expression: " #cond "\n"); \ 193 mlog(ML_ERROR, fmt, ##args); \ 194 BUG(); \ 195 } \ 196 } while (0) 197 198 #include <linux/kobject.h> 199 #include <linux/sysfs.h> 200 int mlog_sys_init(struct kset *o2cb_subsys); 201 void mlog_sys_shutdown(void); 202 203 #endif /* O2CLUSTER_MASKLOG_H */ 204