xref: /linux/fs/ocfs2/cluster/masklog.h (revision 3f6c148df42d98f0991baf4353497d380a30bc19)
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 mlog.c! */
85 #define ML_ENTRY	0x0000000000000001ULL /* func call entry */
86 #define ML_EXIT		0x0000000000000002ULL /* func call exit */
87 #define ML_TCP		0x0000000000000004ULL /* net cluster/tcp.c */
88 #define ML_MSG		0x0000000000000008ULL /* net network messages */
89 #define ML_SOCKET	0x0000000000000010ULL /* net socket lifetime */
90 #define ML_HEARTBEAT	0x0000000000000020ULL /* hb all heartbeat tracking */
91 #define ML_HB_BIO	0x0000000000000040ULL /* hb io tracing */
92 #define ML_DLMFS	0x0000000000000080ULL /* dlm user dlmfs */
93 #define ML_DLM		0x0000000000000100ULL /* dlm general debugging */
94 #define ML_DLM_DOMAIN	0x0000000000000200ULL /* dlm domain debugging */
95 #define ML_DLM_THREAD	0x0000000000000400ULL /* dlm domain thread */
96 #define ML_DLM_MASTER	0x0000000000000800ULL /* dlm master functions */
97 #define ML_DLM_RECOVERY	0x0000000000001000ULL /* dlm master functions */
98 #define ML_AIO		0x0000000000002000ULL /* ocfs2 aio read and write */
99 #define ML_JOURNAL	0x0000000000004000ULL /* ocfs2 journalling functions */
100 #define ML_DISK_ALLOC	0x0000000000008000ULL /* ocfs2 disk allocation */
101 #define ML_SUPER	0x0000000000010000ULL /* ocfs2 mount / umount */
102 #define ML_FILE_IO	0x0000000000020000ULL /* ocfs2 file I/O */
103 #define ML_EXTENT_MAP	0x0000000000040000ULL /* ocfs2 extent map caching */
104 #define ML_DLM_GLUE	0x0000000000080000ULL /* ocfs2 dlm glue layer */
105 #define ML_BH_IO	0x0000000000100000ULL /* ocfs2 buffer I/O */
106 #define ML_UPTODATE	0x0000000000200000ULL /* ocfs2 caching sequence #'s */
107 #define ML_NAMEI	0x0000000000400000ULL /* ocfs2 directory / namespace */
108 #define ML_INODE	0x0000000000800000ULL /* ocfs2 inode manipulation */
109 #define ML_VOTE		0x0000000001000000ULL /* ocfs2 node messaging  */
110 #define ML_DCACHE	0x0000000002000000ULL /* ocfs2 dcache operations */
111 #define ML_CONN		0x0000000004000000ULL /* net connection management */
112 #define ML_QUORUM	0x0000000008000000ULL /* net connection quorum */
113 #define ML_EXPORT	0x0000000010000000ULL /* ocfs2 export operations */
114 #define ML_XATTR	0x0000000020000000ULL /* ocfs2 extended attributes */
115 #define ML_QUOTA	0x0000000040000000ULL /* ocfs2 quota operations */
116 #define ML_REFCOUNT	0x0000000080000000ULL /* refcount tree operations */
117 #define ML_BASTS	0x0000001000000000ULL /* dlmglue asts and basts */
118 /* bits that are infrequently given and frequently matched in the high word */
119 #define ML_ERROR	0x0000000100000000ULL /* sent to KERN_ERR */
120 #define ML_NOTICE	0x0000000200000000ULL /* setn to KERN_NOTICE */
121 #define ML_KTHREAD	0x0000000400000000ULL /* kernel thread activity */
122 
123 #define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
124 #define MLOG_INITIAL_NOT_MASK (ML_ENTRY|ML_EXIT)
125 #ifndef MLOG_MASK_PREFIX
126 #define MLOG_MASK_PREFIX 0
127 #endif
128 
129 /*
130  * When logging is disabled, force the bit test to 0 for anything other
131  * than errors and notices, allowing gcc to remove the code completely.
132  * When enabled, allow all masks.
133  */
134 #if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
135 #define ML_ALLOWED_BITS ~0
136 #else
137 #define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
138 #endif
139 
140 #define MLOG_MAX_BITS 64
141 
142 struct mlog_bits {
143 	unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG];
144 };
145 
146 extern struct mlog_bits mlog_and_bits, mlog_not_bits;
147 
148 #if BITS_PER_LONG == 32
149 
150 #define __mlog_test_u64(mask, bits)			\
151 	( (u32)(mask & 0xffffffff) & bits.words[0] || 	\
152 	  ((u64)(mask) >> 32) & bits.words[1] )
153 #define __mlog_set_u64(mask, bits) do {			\
154 	bits.words[0] |= (u32)(mask & 0xffffffff);	\
155        	bits.words[1] |= (u64)(mask) >> 32;		\
156 } while (0)
157 #define __mlog_clear_u64(mask, bits) do {		\
158 	bits.words[0] &= ~((u32)(mask & 0xffffffff));	\
159        	bits.words[1] &= ~((u64)(mask) >> 32);		\
160 } while (0)
161 #define MLOG_BITS_RHS(mask) {				\
162 	{						\
163 		[0] = (u32)(mask & 0xffffffff),		\
164 		[1] = (u64)(mask) >> 32,		\
165 	}						\
166 }
167 
168 #else /* 32bit long above, 64bit long below */
169 
170 #define __mlog_test_u64(mask, bits)	((mask) & bits.words[0])
171 #define __mlog_set_u64(mask, bits) do {		\
172 	bits.words[0] |= (mask);		\
173 } while (0)
174 #define __mlog_clear_u64(mask, bits) do {	\
175 	bits.words[0] &= ~(mask);		\
176 } while (0)
177 #define MLOG_BITS_RHS(mask) { { (mask) } }
178 
179 #endif
180 
181 /*
182  * smp_processor_id() "helpfully" screams when called outside preemptible
183  * regions in current kernels.  sles doesn't have the variants that don't
184  * scream.  just do this instead of trying to guess which we're building
185  * against.. *sigh*.
186  */
187 #define __mlog_cpu_guess ({		\
188 	unsigned long _cpu = get_cpu();	\
189 	put_cpu();			\
190 	_cpu;				\
191 })
192 
193 /* In the following two macros, the whitespace after the ',' just
194  * before ##args is intentional. Otherwise, gcc 2.95 will eat the
195  * previous token if args expands to nothing.
196  */
197 #define __mlog_printk(level, fmt, args...)				\
198 	printk(level "(%s,%u,%lu):%s:%d " fmt, current->comm,		\
199 	       task_pid_nr(current), __mlog_cpu_guess,			\
200 	       __PRETTY_FUNCTION__, __LINE__ , ##args)
201 
202 #define mlog(mask, fmt, args...) do {					\
203 	u64 __m = MLOG_MASK_PREFIX | (mask);				\
204 	if ((__m & ML_ALLOWED_BITS) &&					\
205 	    __mlog_test_u64(__m, mlog_and_bits) &&			\
206 	    !__mlog_test_u64(__m, mlog_not_bits)) {			\
207 		if (__m & ML_ERROR)					\
208 			__mlog_printk(KERN_ERR, "ERROR: "fmt , ##args);	\
209 		else if (__m & ML_NOTICE)				\
210 			__mlog_printk(KERN_NOTICE, fmt , ##args);	\
211 		else __mlog_printk(KERN_INFO, fmt , ##args);		\
212 	}								\
213 } while (0)
214 
215 #define mlog_errno(st) do {						\
216 	int _st = (st);							\
217 	if (_st != -ERESTARTSYS && _st != -EINTR &&			\
218 	    _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC)		\
219 		mlog(ML_ERROR, "status = %lld\n", (long long)_st);	\
220 } while (0)
221 
222 #if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
223 #define mlog_entry(fmt, args...) do {					\
224 	mlog(ML_ENTRY, "ENTRY:" fmt , ##args);				\
225 } while (0)
226 
227 #define mlog_entry_void() do {						\
228 	mlog(ML_ENTRY, "ENTRY:\n");					\
229 } while (0)
230 
231 /*
232  * We disable this for sparse.
233  */
234 #if !defined(__CHECKER__)
235 #define mlog_exit(st) do {						     \
236 	if (__builtin_types_compatible_p(typeof(st), unsigned long))	     \
237 		mlog(ML_EXIT, "EXIT: %lu\n", (unsigned long) (st));	     \
238 	else if (__builtin_types_compatible_p(typeof(st), signed long))      \
239 		mlog(ML_EXIT, "EXIT: %ld\n", (signed long) (st));	     \
240 	else if (__builtin_types_compatible_p(typeof(st), unsigned int)	     \
241 		 || __builtin_types_compatible_p(typeof(st), unsigned short) \
242 		 || __builtin_types_compatible_p(typeof(st), unsigned char)) \
243 		mlog(ML_EXIT, "EXIT: %u\n", (unsigned int) (st));	     \
244 	else if (__builtin_types_compatible_p(typeof(st), signed int)	     \
245 		 || __builtin_types_compatible_p(typeof(st), signed short)   \
246 		 || __builtin_types_compatible_p(typeof(st), signed char))   \
247 		mlog(ML_EXIT, "EXIT: %d\n", (signed int) (st));		     \
248 	else if (__builtin_types_compatible_p(typeof(st), long long))	     \
249 		mlog(ML_EXIT, "EXIT: %lld\n", (long long) (st));	     \
250 	else								     \
251 		mlog(ML_EXIT, "EXIT: %llu\n", (unsigned long long) (st));    \
252 } while (0)
253 #else
254 #define mlog_exit(st) do {						     \
255 	mlog(ML_EXIT, "EXIT: %lld\n", (long long) (st));		     \
256 } while (0)
257 #endif
258 
259 #define mlog_exit_ptr(ptr) do {						\
260 	mlog(ML_EXIT, "EXIT: %p\n", ptr);				\
261 } while (0)
262 
263 #define mlog_exit_void() do {						\
264 	mlog(ML_EXIT, "EXIT\n");					\
265 } while (0)
266 #else
267 #define mlog_entry(...)  do { } while (0)
268 #define mlog_entry_void(...)  do { } while (0)
269 #define mlog_exit(...)  do { } while (0)
270 #define mlog_exit_ptr(...)  do { } while (0)
271 #define mlog_exit_void(...)  do { } while (0)
272 #endif  /* defined(CONFIG_OCFS2_DEBUG_MASKLOG) */
273 
274 #define mlog_bug_on_msg(cond, fmt, args...) do {			\
275 	if (cond) {							\
276 		mlog(ML_ERROR, "bug expression: " #cond "\n");		\
277 		mlog(ML_ERROR, fmt, ##args);				\
278 		BUG();							\
279 	}								\
280 } while (0)
281 
282 #include <linux/kobject.h>
283 #include <linux/sysfs.h>
284 int mlog_sys_init(struct kset *o2cb_subsys);
285 void mlog_sys_shutdown(void);
286 
287 #endif /* O2CLUSTER_MASKLOG_H */
288