/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2005 Oracle. All rights reserved. */ #ifndef O2CLUSTER_MASKLOG_H #define O2CLUSTER_MASKLOG_H /* * For now this is a trivial wrapper around printk() that gives the critical * ability to enable sets of debugging output at run-time. In the future this * will almost certainly be redirected to relayfs so that it can pay a * substantially lower heisenberg tax. * * Callers associate the message with a bitmask and a global bitmask is * maintained with help from /proc. If any of the bits match the message is * output. * * We must have efficient bit tests on i386 and it seems gcc still emits crazy * code for the 64bit compare. It emits very good code for the dual unsigned * long tests, though, completely avoiding tests that can never pass if the * caller gives a constant bitmask that fills one of the longs with all 0s. So * the desire is to have almost all of the calls decided on by comparing just * one of the longs. This leads to having infrequently given bits that are * frequently matched in the high bits. * * _ERROR and _NOTICE are used for messages that always go to the console and * have appropriate KERN_ prefixes. We wrap these in our function instead of * just calling printk() so that this can eventually make its way through * relayfs along with the debugging messages. Everything else gets KERN_DEBUG. * The inline tests and macro dance give GCC the opportunity to quite cleverly * only emit the appropriate printk() when the caller passes in a constant * mask, as is almost always the case. * * All this bitmask nonsense is managed from the files under * /sys/fs/o2cb/logmask/. Reading the files gives a straightforward * indication of which bits are allowed (allow) or denied (off/deny). * ENTRY deny * EXIT deny * TCP off * MSG off * SOCKET off * ERROR allow * NOTICE allow * * Writing changes the state of a given bit and requires a strictly formatted * single write() call: * * write(fd, "allow", 5); * * Echoing allow/deny/off string into the logmask files can flip the bits * on or off as expected; here is the bash script for example: * * log_mask="/sys/fs/o2cb/log_mask" * for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do * echo allow >"$log_mask"/"$node" * done * * The debugfs.ocfs2 tool can also flip the bits with the -l option: * * debugfs.ocfs2 -l TCP allow */ /* for task_struct */ #include <linux/sched.h> /* bits that are frequently given and infrequently matched in the low word */ /* NOTE: If you add a flag, you need to also update masklog.c! */ #define ML_TCP 0x0000000000000001ULL /* net cluster/tcp.c */ #define ML_MSG 0x0000000000000002ULL /* net network messages */ #define ML_SOCKET 0x0000000000000004ULL /* net socket lifetime */ #define ML_HEARTBEAT 0x0000000000000008ULL /* hb all heartbeat tracking */ #define ML_HB_BIO 0x0000000000000010ULL /* hb io tracing */ #define ML_DLMFS 0x0000000000000020ULL /* dlm user dlmfs */ #define ML_DLM 0x0000000000000040ULL /* dlm general debugging */ #define ML_DLM_DOMAIN 0x0000000000000080ULL /* dlm domain debugging */ #define ML_DLM_THREAD 0x0000000000000100ULL /* dlm domain thread */ #define ML_DLM_MASTER 0x0000000000000200ULL /* dlm master functions */ #define ML_DLM_RECOVERY 0x0000000000000400ULL /* dlm master functions */ #define ML_DLM_GLUE 0x0000000000000800ULL /* ocfs2 dlm glue layer */ #define ML_VOTE 0x0000000000001000ULL /* ocfs2 node messaging */ #define ML_CONN 0x0000000000002000ULL /* net connection management */ #define ML_QUORUM 0x0000000000004000ULL /* net connection quorum */ #define ML_BASTS 0x0000000000008000ULL /* dlmglue asts and basts */ #define ML_CLUSTER 0x0000000000010000ULL /* cluster stack */ /* bits that are infrequently given and frequently matched in the high word */ #define ML_ERROR 0x1000000000000000ULL /* sent to KERN_ERR */ #define ML_NOTICE 0x2000000000000000ULL /* setn to KERN_NOTICE */ #define ML_KTHREAD 0x4000000000000000ULL /* kernel thread activity */ #define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE) #ifndef MLOG_MASK_PREFIX #define MLOG_MASK_PREFIX 0 #endif /* * When logging is disabled, force the bit test to 0 for anything other * than errors and notices, allowing gcc to remove the code completely. * When enabled, allow all masks. */ #if defined(CONFIG_OCFS2_DEBUG_MASKLOG) #define ML_ALLOWED_BITS ~0 #else #define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE) #endif #define MLOG_MAX_BITS 64 struct mlog_bits { unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG]; }; extern struct mlog_bits mlog_and_bits, mlog_not_bits; #if BITS_PER_LONG == 32 #define __mlog_test_u64(mask, bits) \ ( (u32)(mask & 0xffffffff) & bits.words[0] || \ ((u64)(mask) >> 32) & bits.words[1] ) #define __mlog_set_u64(mask, bits) do { \ bits.words[0] |= (u32)(mask & 0xffffffff); \ bits.words[1] |= (u64)(mask) >> 32; \ } while (0) #define __mlog_clear_u64(mask, bits) do { \ bits.words[0] &= ~((u32)(mask & 0xffffffff)); \ bits.words[1] &= ~((u64)(mask) >> 32); \ } while (0) #define MLOG_BITS_RHS(mask) { \ { \ [0] = (u32)(mask & 0xffffffff), \ [1] = (u64)(mask) >> 32, \ } \ } #else /* 32bit long above, 64bit long below */ #define __mlog_test_u64(mask, bits) ((mask) & bits.words[0]) #define __mlog_set_u64(mask, bits) do { \ bits.words[0] |= (mask); \ } while (0) #define __mlog_clear_u64(mask, bits) do { \ bits.words[0] &= ~(mask); \ } while (0) #define MLOG_BITS_RHS(mask) { { (mask) } } #endif __printf(4, 5) void __mlog_printk(const u64 *m, const char *func, int line, const char *fmt, ...); /* * Testing before the __mlog_printk call lets the compiler eliminate the * call completely when (m & ML_ALLOWED_BITS) is 0. */ #define mlog(mask, fmt, ...) \ do { \ u64 _m = MLOG_MASK_PREFIX | (mask); \ if (_m & ML_ALLOWED_BITS) \ __mlog_printk(&_m, __func__, __LINE__, fmt, \ ##__VA_ARGS__); \ } while (0) #define mlog_ratelimited(mask, fmt, ...) \ do { \ static DEFINE_RATELIMIT_STATE(_rs, \ DEFAULT_RATELIMIT_INTERVAL, \ DEFAULT_RATELIMIT_BURST); \ if (__ratelimit(&_rs)) \ mlog(mask, fmt, ##__VA_ARGS__); \ } while (0) #define mlog_errno(st) ({ \ int _st = (st); \ if (_st != -ERESTARTSYS && _st != -EINTR && \ _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC && \ _st != -EDQUOT) \ mlog(ML_ERROR, "status = %lld\n", (long long)_st); \ _st; \ }) #define mlog_bug_on_msg(cond, fmt, args...) do { \ if (cond) { \ mlog(ML_ERROR, "bug expression: " #cond "\n"); \ mlog(ML_ERROR, fmt, ##args); \ BUG(); \ } \ } while (0) #include <linux/kobject.h> #include <linux/sysfs.h> int mlog_sys_init(struct kset *o2cb_subsys); void mlog_sys_shutdown(void); #endif /* O2CLUSTER_MASKLOG_H */
