[linux.git] / fs / ocfs2 / cluster / masklog.h

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * Copyright (C) 2005 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#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 */
Commit	Line	Data
52fd3d6f ZB	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	*
2b53bc7b CL	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
52fd3d6f ZB	56	* TCP off
	57	* MSG off
	58	* SOCKET off
2b53bc7b CL	59	* ERROR allow
2b53bc7b CL	60	* NOTICE allow
52fd3d6f ZB	61	*
	62	* Writing changes the state of a given bit and requires a strictly formatted
	63	* single write() call:
	64	*
2b53bc7b	65	* write(fd, "allow", 5);
52fd3d6f	66	*
2b53bc7b CL	67	* Echoing allow/deny/off string into the logmask files can flip the bits
2b53bc7b CL	68	* on or off as expected; here is the bash script for example:
52fd3d6f	69	*
2b53bc7b CL	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
52fd3d6f	74	*
2b53bc7b CL	75	* The debugfs.ocfs2 tool can also flip the bits with the -l option:
	76	*
	77	* debugfs.ocfs2 -l TCP allow
52fd3d6f ZB	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 */
41b41a26	84	/* NOTE: If you add a flag, you need to also update masklog.c! */
b4e1b7e8 TM	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 */
41b41a26	102
52fd3d6f	103	/* bits that are infrequently given and frequently matched in the high word */
41b41a26 SM	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 */
52fd3d6f ZB	107
52fd3d6f ZB	108	#define MLOG_INITIAL_AND_MASK (ML_ERROR\|ML_NOTICE)
52fd3d6f ZB	109	#ifndef MLOG_MASK_PREFIX
	110	#define MLOG_MASK_PREFIX 0
	111	#endif
	112
2b388c67 JB	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
52fd3d6f ZB	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
7c2bd2f9 JP	165	__printf(4, 5)
	166	void __mlog_printk(const u64 m, const char func, int line,
	167	const char *fmt, ...);
52fd3d6f	168
7c2bd2f9 JP	169	/*
	170	* Testing before the __mlog_printk call lets the compiler eliminate the
	171	* call completely when (m & ML_ALLOWED_BITS) is 0.
52fd3d6f	172	*/
7c2bd2f9 JP	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__); \
52fd3d6f ZB	179	} while (0)
52fd3d6f ZB	180
5040f8df WW	181	#define mlog_ratelimited(mask, fmt, ...) \
	182	do { \
	183	static DEFINE_RATELIMIT_STATE(_rs, \
	184	DEFAULT_RATELIMIT_INTERVAL, \
	185	DEFAULT_RATELIMIT_BURST); \
	186	if (__ratelimit(&_rs)) \
	187	mlog(mask, fmt, ##__VA_ARGS__); \
	188	} while (0)
	189
1d5b8977	190	#define mlog_errno(st) ({ \
52fd3d6f ZB	191	int _st = (st); \
52fd3d6f ZB	192	if (_st != -ERESTARTSYS && _st != -EINTR && \
910bffe0 JB	193	_st != AOP_TRUNCATED_PAGE && _st != -ENOSPC && \
910bffe0 JB	194	_st != -EDQUOT) \
52fd3d6f	195	mlog(ML_ERROR, "status = %lld\n", (long long)_st); \
1d5b8977 AM	196	_st; \
1d5b8977 AM	197	})
52fd3d6f	198
52fd3d6f ZB	199	#define mlog_bug_on_msg(cond, fmt, args...) do { \
	200	if (cond) { \
	201	mlog(ML_ERROR, "bug expression: " #cond "\n"); \
	202	mlog(ML_ERROR, fmt, ##args); \
	203	BUG(); \
	204	} \
	205	} while (0)
	206
52fd3d6f ZB	207	#include <linux/kobject.h>
52fd3d6f ZB	208	#include <linux/sysfs.h>
823bccfc	209	int mlog_sys_init(struct kset *o2cb_subsys);
52fd3d6f ZB	210	void mlog_sys_shutdown(void);
	211
	212	#endif /* O2CLUSTER_MASKLOG_H */