1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * Copyright (C) 2005 Oracle. All rights reserved.
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.
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.
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.
22 #ifndef O2CLUSTER_MASKLOG_H
23 #define O2CLUSTER_MASKLOG_H
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.
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
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.
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.
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).
62 * Writing changes the state of a given bit and requires a strictly formatted
63 * single write() call:
65 * write(fd, "allow", 5);
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:
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"
75 * The debugfs.ocfs2 tool can also flip the bits with the -l option:
77 * debugfs.ocfs2 -l TCP allow
81 #include <linux/sched.h>
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 0x0000000000000004ULL /* net cluster/tcp.c */
86 #define ML_MSG 0x0000000000000008ULL /* net network messages */
87 #define ML_SOCKET 0x0000000000000010ULL /* net socket lifetime */
88 #define ML_HEARTBEAT 0x0000000000000020ULL /* hb all heartbeat tracking */
89 #define ML_HB_BIO 0x0000000000000040ULL /* hb io tracing */
90 #define ML_DLMFS 0x0000000000000080ULL /* dlm user dlmfs */
91 #define ML_DLM 0x0000000000000100ULL /* dlm general debugging */
92 #define ML_DLM_DOMAIN 0x0000000000000200ULL /* dlm domain debugging */
93 #define ML_DLM_THREAD 0x0000000000000400ULL /* dlm domain thread */
94 #define ML_DLM_MASTER 0x0000000000000800ULL /* dlm master functions */
95 #define ML_DLM_RECOVERY 0x0000000000001000ULL /* dlm master functions */
96 #define ML_AIO 0x0000000000002000ULL /* ocfs2 aio read and write */
97 #define ML_JOURNAL 0x0000000000004000ULL /* ocfs2 journalling functions */
98 #define ML_DLM_GLUE 0x0000000000080000ULL /* ocfs2 dlm glue layer */
99 #define ML_BH_IO 0x0000000000100000ULL /* ocfs2 buffer I/O */
100 #define ML_UPTODATE 0x0000000000200000ULL /* ocfs2 caching sequence #'s */
101 #define ML_VOTE 0x0000000001000000ULL /* ocfs2 node messaging */
102 #define ML_CONN 0x0000000004000000ULL /* net connection management */
103 #define ML_QUORUM 0x0000000008000000ULL /* net connection quorum */
104 #define ML_EXPORT 0x0000000010000000ULL /* ocfs2 export operations */
105 #define ML_BASTS 0x0000000100000000ULL /* dlmglue asts and basts */
106 #define ML_CLUSTER 0x0000000400000000ULL /* cluster stack */
108 /* bits that are infrequently given and frequently matched in the high word */
109 #define ML_ERROR 0x1000000000000000ULL /* sent to KERN_ERR */
110 #define ML_NOTICE 0x2000000000000000ULL /* setn to KERN_NOTICE */
111 #define ML_KTHREAD 0x4000000000000000ULL /* kernel thread activity */
113 #define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
114 #ifndef MLOG_MASK_PREFIX
115 #define MLOG_MASK_PREFIX 0
119 * When logging is disabled, force the bit test to 0 for anything other
120 * than errors and notices, allowing gcc to remove the code completely.
121 * When enabled, allow all masks.
123 #if defined(CONFIG_OCFS2_DEBUG_MASKLOG)
124 #define ML_ALLOWED_BITS ~0
126 #define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
129 #define MLOG_MAX_BITS 64
132 unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG];
135 extern struct mlog_bits mlog_and_bits, mlog_not_bits;
137 #if BITS_PER_LONG == 32
139 #define __mlog_test_u64(mask, bits) \
140 ( (u32)(mask & 0xffffffff) & bits.words[0] || \
141 ((u64)(mask) >> 32) & bits.words[1] )
142 #define __mlog_set_u64(mask, bits) do { \
143 bits.words[0] |= (u32)(mask & 0xffffffff); \
144 bits.words[1] |= (u64)(mask) >> 32; \
146 #define __mlog_clear_u64(mask, bits) do { \
147 bits.words[0] &= ~((u32)(mask & 0xffffffff)); \
148 bits.words[1] &= ~((u64)(mask) >> 32); \
150 #define MLOG_BITS_RHS(mask) { \
152 [0] = (u32)(mask & 0xffffffff), \
153 [1] = (u64)(mask) >> 32, \
157 #else /* 32bit long above, 64bit long below */
159 #define __mlog_test_u64(mask, bits) ((mask) & bits.words[0])
160 #define __mlog_set_u64(mask, bits) do { \
161 bits.words[0] |= (mask); \
163 #define __mlog_clear_u64(mask, bits) do { \
164 bits.words[0] &= ~(mask); \
166 #define MLOG_BITS_RHS(mask) { { (mask) } }
171 * smp_processor_id() "helpfully" screams when called outside preemptible
172 * regions in current kernels. sles doesn't have the variants that don't
173 * scream. just do this instead of trying to guess which we're building
176 #define __mlog_cpu_guess ({ \
177 unsigned long _cpu = get_cpu(); \
182 /* In the following two macros, the whitespace after the ',' just
183 * before ##args is intentional. Otherwise, gcc 2.95 will eat the
184 * previous token if args expands to nothing.
186 #define __mlog_printk(level, fmt, args...) \
187 printk(level "(%s,%u,%lu):%s:%d " fmt, current->comm, \
188 task_pid_nr(current), __mlog_cpu_guess, \
189 __PRETTY_FUNCTION__, __LINE__ , ##args)
191 #define mlog(mask, fmt, args...) do { \
192 u64 __m = MLOG_MASK_PREFIX | (mask); \
193 if ((__m & ML_ALLOWED_BITS) && \
194 __mlog_test_u64(__m, mlog_and_bits) && \
195 !__mlog_test_u64(__m, mlog_not_bits)) { \
196 if (__m & ML_ERROR) \
197 __mlog_printk(KERN_ERR, "ERROR: "fmt , ##args); \
198 else if (__m & ML_NOTICE) \
199 __mlog_printk(KERN_NOTICE, fmt , ##args); \
200 else __mlog_printk(KERN_INFO, fmt , ##args); \
204 #define mlog_errno(st) do { \
206 if (_st != -ERESTARTSYS && _st != -EINTR && \
207 _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC) \
208 mlog(ML_ERROR, "status = %lld\n", (long long)_st); \
211 #define mlog_bug_on_msg(cond, fmt, args...) do { \
213 mlog(ML_ERROR, "bug expression: " #cond "\n"); \
214 mlog(ML_ERROR, fmt, ##args); \
219 #include <linux/kobject.h>
220 #include <linux/sysfs.h>
221 int mlog_sys_init(struct kset *o2cb_subsys);
222 void mlog_sys_shutdown(void);
224 #endif /* O2CLUSTER_MASKLOG_H */