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 126struct mlog_bits { 127 unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG]; 128}; 129 130extern 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/* 166 * smp_processor_id() "helpfully" screams when called outside preemptible 167 * regions in current kernels. sles doesn't have the variants that don't 168 * scream. just do this instead of trying to guess which we're building 169 * against.. *sigh*. 170 */ 171#define __mlog_cpu_guess ({ \ 172 unsigned long _cpu = get_cpu(); \ 173 put_cpu(); \ 174 _cpu; \ 175}) 176 177/* In the following two macros, the whitespace after the ',' just 178 * before ##args is intentional. Otherwise, gcc 2.95 will eat the 179 * previous token if args expands to nothing. 180 */ 181#define __mlog_printk(level, fmt, args...) \ 182 printk(level "(%s,%u,%lu):%s:%d " fmt, current->comm, \ 183 task_pid_nr(current), __mlog_cpu_guess, \ 184 __PRETTY_FUNCTION__, __LINE__ , ##args) 185 186#define mlog(mask, fmt, args...) do { \ 187 u64 __m = MLOG_MASK_PREFIX | (mask); \ 188 if ((__m & ML_ALLOWED_BITS) && \ 189 __mlog_test_u64(__m, mlog_and_bits) && \ 190 !__mlog_test_u64(__m, mlog_not_bits)) { \ 191 if (__m & ML_ERROR) \ 192 __mlog_printk(KERN_ERR, "ERROR: "fmt , ##args); \ 193 else if (__m & ML_NOTICE) \ 194 __mlog_printk(KERN_NOTICE, fmt , ##args); \ 195 else __mlog_printk(KERN_INFO, fmt , ##args); \ 196 } \ 197} while (0) 198 199#define mlog_errno(st) do { \ 200 int _st = (st); \ 201 if (_st != -ERESTARTSYS && _st != -EINTR && \ 202 _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC && \ 203 _st != -EDQUOT) \ 204 mlog(ML_ERROR, "status = %lld\n", (long long)_st); \ 205} while (0) 206 207#define mlog_bug_on_msg(cond, fmt, args...) do { \ 208 if (cond) { \ 209 mlog(ML_ERROR, "bug expression: " #cond "\n"); \ 210 mlog(ML_ERROR, fmt, ##args); \ 211 BUG(); \ 212 } \ 213} while (0) 214 215#include <linux/kobject.h> 216#include <linux/sysfs.h> 217int mlog_sys_init(struct kset *o2cb_subsys); 218void mlog_sys_shutdown(void); 219 220#endif /* O2CLUSTER_MASKLOG_H */ 221