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Diffstat (limited to 'fs/ocfs2/cluster/masklog.h')
| -rw-r--r-- | fs/ocfs2/cluster/masklog.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/masklog.h b/fs/ocfs2/cluster/masklog.h new file mode 100644 index 000000000..446e452ac --- /dev/null +++ b/fs/ocfs2/cluster/masklog.h @@ -0,0 +1,198 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * 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 appropriage 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 */ |