1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | /* |
3 | * Copyright (C) 2005 Oracle. All rights reserved. |
4 | */ |
5 | |
6 | #ifndef O2CLUSTER_MASKLOG_H |
7 | #define O2CLUSTER_MASKLOG_H |
8 | |
9 | /* |
10 | * For now this is a trivial wrapper around printk() that gives the critical |
11 | * ability to enable sets of debugging output at run-time. In the future this |
12 | * will almost certainly be redirected to relayfs so that it can pay a |
13 | * substantially lower heisenberg tax. |
14 | * |
15 | * Callers associate the message with a bitmask and a global bitmask is |
16 | * maintained with help from /proc. If any of the bits match the message is |
17 | * output. |
18 | * |
19 | * We must have efficient bit tests on i386 and it seems gcc still emits crazy |
20 | * code for the 64bit compare. It emits very good code for the dual unsigned |
21 | * long tests, though, completely avoiding tests that can never pass if the |
22 | * caller gives a constant bitmask that fills one of the longs with all 0s. So |
23 | * the desire is to have almost all of the calls decided on by comparing just |
24 | * one of the longs. This leads to having infrequently given bits that are |
25 | * frequently matched in the high bits. |
26 | * |
27 | * _ERROR and _NOTICE are used for messages that always go to the console and |
28 | * have appropriate KERN_ prefixes. We wrap these in our function instead of |
29 | * just calling printk() so that this can eventually make its way through |
30 | * relayfs along with the debugging messages. Everything else gets KERN_DEBUG. |
31 | * The inline tests and macro dance give GCC the opportunity to quite cleverly |
32 | * only emit the appropriage printk() when the caller passes in a constant |
33 | * mask, as is almost always the case. |
34 | * |
35 | * All this bitmask nonsense is managed from the files under |
36 | * /sys/fs/o2cb/logmask/. Reading the files gives a straightforward |
37 | * indication of which bits are allowed (allow) or denied (off/deny). |
38 | * ENTRY deny |
39 | * EXIT deny |
40 | * TCP off |
41 | * MSG off |
42 | * SOCKET off |
43 | * ERROR allow |
44 | * NOTICE allow |
45 | * |
46 | * Writing changes the state of a given bit and requires a strictly formatted |
47 | * single write() call: |
48 | * |
49 | * write(fd, "allow", 5); |
50 | * |
51 | * Echoing allow/deny/off string into the logmask files can flip the bits |
52 | * on or off as expected; here is the bash script for example: |
53 | * |
54 | * log_mask="/sys/fs/o2cb/log_mask" |
55 | * for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do |
56 | * echo allow >"$log_mask"/"$node" |
57 | * done |
58 | * |
59 | * The debugfs.ocfs2 tool can also flip the bits with the -l option: |
60 | * |
61 | * debugfs.ocfs2 -l TCP allow |
62 | */ |
63 | |
64 | /* for task_struct */ |
65 | #include <linux/sched.h> |
66 | |
67 | /* bits that are frequently given and infrequently matched in the low word */ |
68 | /* NOTE: If you add a flag, you need to also update masklog.c! */ |
69 | #define ML_TCP 0x0000000000000001ULL /* net cluster/tcp.c */ |
70 | #define ML_MSG 0x0000000000000002ULL /* net network messages */ |
71 | #define ML_SOCKET 0x0000000000000004ULL /* net socket lifetime */ |
72 | #define ML_HEARTBEAT 0x0000000000000008ULL /* hb all heartbeat tracking */ |
73 | #define ML_HB_BIO 0x0000000000000010ULL /* hb io tracing */ |
74 | #define ML_DLMFS 0x0000000000000020ULL /* dlm user dlmfs */ |
75 | #define ML_DLM 0x0000000000000040ULL /* dlm general debugging */ |
76 | #define ML_DLM_DOMAIN 0x0000000000000080ULL /* dlm domain debugging */ |
77 | #define ML_DLM_THREAD 0x0000000000000100ULL /* dlm domain thread */ |
78 | #define ML_DLM_MASTER 0x0000000000000200ULL /* dlm master functions */ |
79 | #define ML_DLM_RECOVERY 0x0000000000000400ULL /* dlm master functions */ |
80 | #define ML_DLM_GLUE 0x0000000000000800ULL /* ocfs2 dlm glue layer */ |
81 | #define ML_VOTE 0x0000000000001000ULL /* ocfs2 node messaging */ |
82 | #define ML_CONN 0x0000000000002000ULL /* net connection management */ |
83 | #define ML_QUORUM 0x0000000000004000ULL /* net connection quorum */ |
84 | #define ML_BASTS 0x0000000000008000ULL /* dlmglue asts and basts */ |
85 | #define ML_CLUSTER 0x0000000000010000ULL /* cluster stack */ |
86 | |
87 | /* bits that are infrequently given and frequently matched in the high word */ |
88 | #define ML_ERROR 0x1000000000000000ULL /* sent to KERN_ERR */ |
89 | #define ML_NOTICE 0x2000000000000000ULL /* setn to KERN_NOTICE */ |
90 | #define ML_KTHREAD 0x4000000000000000ULL /* kernel thread activity */ |
91 | |
92 | #define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE) |
93 | #ifndef MLOG_MASK_PREFIX |
94 | #define MLOG_MASK_PREFIX 0 |
95 | #endif |
96 | |
97 | /* |
98 | * When logging is disabled, force the bit test to 0 for anything other |
99 | * than errors and notices, allowing gcc to remove the code completely. |
100 | * When enabled, allow all masks. |
101 | */ |
102 | #if defined(CONFIG_OCFS2_DEBUG_MASKLOG) |
103 | #define ML_ALLOWED_BITS ~0 |
104 | #else |
105 | #define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE) |
106 | #endif |
107 | |
108 | #define MLOG_MAX_BITS 64 |
109 | |
110 | struct mlog_bits { |
111 | unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG]; |
112 | }; |
113 | |
114 | extern struct mlog_bits mlog_and_bits, mlog_not_bits; |
115 | |
116 | #if BITS_PER_LONG == 32 |
117 | |
118 | #define __mlog_test_u64(mask, bits) \ |
119 | ( (u32)(mask & 0xffffffff) & bits.words[0] || \ |
120 | ((u64)(mask) >> 32) & bits.words[1] ) |
121 | #define __mlog_set_u64(mask, bits) do { \ |
122 | bits.words[0] |= (u32)(mask & 0xffffffff); \ |
123 | bits.words[1] |= (u64)(mask) >> 32; \ |
124 | } while (0) |
125 | #define __mlog_clear_u64(mask, bits) do { \ |
126 | bits.words[0] &= ~((u32)(mask & 0xffffffff)); \ |
127 | bits.words[1] &= ~((u64)(mask) >> 32); \ |
128 | } while (0) |
129 | #define MLOG_BITS_RHS(mask) { \ |
130 | { \ |
131 | [0] = (u32)(mask & 0xffffffff), \ |
132 | [1] = (u64)(mask) >> 32, \ |
133 | } \ |
134 | } |
135 | |
136 | #else /* 32bit long above, 64bit long below */ |
137 | |
138 | #define __mlog_test_u64(mask, bits) ((mask) & bits.words[0]) |
139 | #define __mlog_set_u64(mask, bits) do { \ |
140 | bits.words[0] |= (mask); \ |
141 | } while (0) |
142 | #define __mlog_clear_u64(mask, bits) do { \ |
143 | bits.words[0] &= ~(mask); \ |
144 | } while (0) |
145 | #define MLOG_BITS_RHS(mask) { { (mask) } } |
146 | |
147 | #endif |
148 | |
149 | __printf(4, 5) |
150 | void __mlog_printk(const u64 *m, const char *func, int line, |
151 | const char *fmt, ...); |
152 | |
153 | /* |
154 | * Testing before the __mlog_printk call lets the compiler eliminate the |
155 | * call completely when (m & ML_ALLOWED_BITS) is 0. |
156 | */ |
157 | #define mlog(mask, fmt, ...) \ |
158 | do { \ |
159 | u64 _m = MLOG_MASK_PREFIX | (mask); \ |
160 | if (_m & ML_ALLOWED_BITS) \ |
161 | __mlog_printk(&_m, __func__, __LINE__, fmt, \ |
162 | ##__VA_ARGS__); \ |
163 | } while (0) |
164 | |
165 | #define mlog_ratelimited(mask, fmt, ...) \ |
166 | do { \ |
167 | static DEFINE_RATELIMIT_STATE(_rs, \ |
168 | DEFAULT_RATELIMIT_INTERVAL, \ |
169 | DEFAULT_RATELIMIT_BURST); \ |
170 | if (__ratelimit(&_rs)) \ |
171 | mlog(mask, fmt, ##__VA_ARGS__); \ |
172 | } while (0) |
173 | |
174 | #define mlog_errno(st) ({ \ |
175 | int _st = (st); \ |
176 | if (_st != -ERESTARTSYS && _st != -EINTR && \ |
177 | _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC && \ |
178 | _st != -EDQUOT) \ |
179 | mlog(ML_ERROR, "status = %lld\n", (long long)_st); \ |
180 | _st; \ |
181 | }) |
182 | |
183 | #define mlog_bug_on_msg(cond, fmt, args...) do { \ |
184 | if (cond) { \ |
185 | mlog(ML_ERROR, "bug expression: " #cond "\n"); \ |
186 | mlog(ML_ERROR, fmt, ##args); \ |
187 | BUG(); \ |
188 | } \ |
189 | } while (0) |
190 | |
191 | #include <linux/kobject.h> |
192 | #include <linux/sysfs.h> |
193 | int mlog_sys_init(struct kset *o2cb_subsys); |
194 | void mlog_sys_shutdown(void); |
195 | |
196 | #endif /* O2CLUSTER_MASKLOG_H */ |
197 | |