diff options
author | Akinobu Mita <akinobu.mita@gmail.com> | 2006-12-08 05:39:43 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-08 11:29:02 -0500 |
commit | 6ff1cb355e628f8fc55fa2d01e269e5e1bbc2fe9 (patch) | |
tree | 393d94b6d7585e4c804d6415afaa11e1d6ec350d | |
parent | de1ba09b214056365d9082982905b255caafb7a2 (diff) |
[PATCH] fault-injection capabilities infrastructure
This patch provides base functions implement to fault-injection
capabilities.
- The function should_fail() is taken from failmalloc-1.0
(http://www.nongnu.org/failmalloc/)
[akpm@osdl.org: cleanups, comments, add __init]
Cc: <okuji@enbug.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Don Mullis <dwm@meer.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | include/linux/fault-inject.h | 69 | ||||
-rw-r--r-- | lib/Kconfig.debug | 12 | ||||
-rw-r--r-- | lib/Makefile | 1 | ||||
-rw-r--r-- | lib/fault-inject.c | 183 |
4 files changed, 265 insertions, 0 deletions
diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h new file mode 100644 index 000000000000..4df4902bc8d8 --- /dev/null +++ b/include/linux/fault-inject.h | |||
@@ -0,0 +1,69 @@ | |||
1 | #ifndef _LINUX_FAULT_INJECT_H | ||
2 | #define _LINUX_FAULT_INJECT_H | ||
3 | |||
4 | #ifdef CONFIG_FAULT_INJECTION | ||
5 | |||
6 | #include <linux/types.h> | ||
7 | #include <linux/debugfs.h> | ||
8 | #include <asm/atomic.h> | ||
9 | |||
10 | /* | ||
11 | * For explanation of the elements of this struct, see | ||
12 | * Documentation/fault-injection/fault-injection.txt | ||
13 | */ | ||
14 | struct fault_attr { | ||
15 | unsigned long probability; | ||
16 | unsigned long interval; | ||
17 | atomic_t times; | ||
18 | atomic_t space; | ||
19 | unsigned long verbose; | ||
20 | |||
21 | unsigned long count; | ||
22 | |||
23 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | ||
24 | |||
25 | struct { | ||
26 | struct dentry *dir; | ||
27 | |||
28 | struct dentry *probability_file; | ||
29 | struct dentry *interval_file; | ||
30 | struct dentry *times_file; | ||
31 | struct dentry *space_file; | ||
32 | struct dentry *verbose_file; | ||
33 | } dentries; | ||
34 | |||
35 | #endif | ||
36 | }; | ||
37 | |||
38 | #define FAULT_ATTR_INITIALIZER { \ | ||
39 | .interval = 1, \ | ||
40 | .times = ATOMIC_INIT(1), \ | ||
41 | } | ||
42 | |||
43 | #define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER | ||
44 | int setup_fault_attr(struct fault_attr *attr, char *str); | ||
45 | void should_fail_srandom(unsigned long entropy); | ||
46 | int should_fail(struct fault_attr *attr, ssize_t size); | ||
47 | |||
48 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | ||
49 | |||
50 | int init_fault_attr_dentries(struct fault_attr *attr, const char *name); | ||
51 | void cleanup_fault_attr_dentries(struct fault_attr *attr); | ||
52 | |||
53 | #else /* CONFIG_FAULT_INJECTION_DEBUG_FS */ | ||
54 | |||
55 | static inline int init_fault_attr_dentries(struct fault_attr *attr, | ||
56 | const char *name) | ||
57 | { | ||
58 | return -ENODEV; | ||
59 | } | ||
60 | |||
61 | static inline void cleanup_fault_attr_dentries(struct fault_attr *attr) | ||
62 | { | ||
63 | } | ||
64 | |||
65 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ | ||
66 | |||
67 | #endif /* CONFIG_FAULT_INJECTION */ | ||
68 | |||
69 | #endif /* _LINUX_FAULT_INJECT_H */ | ||
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2c133c098607..35228b3e7e92 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug | |||
@@ -413,3 +413,15 @@ config LKDTM | |||
413 | 413 | ||
414 | Documentation on how to use the module can be found in | 414 | Documentation on how to use the module can be found in |
415 | drivers/misc/lkdtm.c | 415 | drivers/misc/lkdtm.c |
416 | |||
417 | config FAULT_INJECTION | ||
418 | bool | ||
419 | |||
420 | config FAULT_INJECTION_DEBUG_FS | ||
421 | bool "Debugfs entries for fault-injection capabilities" | ||
422 | depends on FAULT_INJECTION && SYSFS | ||
423 | select DEBUG_FS | ||
424 | help | ||
425 | This option enable configuration of fault-injection capabilities via | ||
426 | debugfs. | ||
427 | |||
diff --git a/lib/Makefile b/lib/Makefile index 6f675c6149a7..2d6106af53cd 100644 --- a/lib/Makefile +++ b/lib/Makefile | |||
@@ -55,6 +55,7 @@ obj-$(CONFIG_SMP) += percpu_counter.o | |||
55 | obj-$(CONFIG_AUDIT_GENERIC) += audit.o | 55 | obj-$(CONFIG_AUDIT_GENERIC) += audit.o |
56 | 56 | ||
57 | obj-$(CONFIG_SWIOTLB) += swiotlb.o | 57 | obj-$(CONFIG_SWIOTLB) += swiotlb.o |
58 | obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o | ||
58 | 59 | ||
59 | lib-$(CONFIG_GENERIC_BUG) += bug.o | 60 | lib-$(CONFIG_GENERIC_BUG) += bug.o |
60 | 61 | ||
diff --git a/lib/fault-inject.c b/lib/fault-inject.c new file mode 100644 index 000000000000..a7cb3afd132a --- /dev/null +++ b/lib/fault-inject.c | |||
@@ -0,0 +1,183 @@ | |||
1 | #include <linux/kernel.h> | ||
2 | #include <linux/init.h> | ||
3 | #include <linux/random.h> | ||
4 | #include <linux/stat.h> | ||
5 | #include <linux/types.h> | ||
6 | #include <linux/fs.h> | ||
7 | #include <linux/module.h> | ||
8 | #include <linux/fault-inject.h> | ||
9 | |||
10 | /* | ||
11 | * setup_fault_attr() is a helper function for various __setup handlers, so it | ||
12 | * returns 0 on error, because that is what __setup handlers do. | ||
13 | */ | ||
14 | int __init setup_fault_attr(struct fault_attr *attr, char *str) | ||
15 | { | ||
16 | unsigned long probability; | ||
17 | unsigned long interval; | ||
18 | int times; | ||
19 | int space; | ||
20 | |||
21 | /* "<interval>,<probability>,<space>,<times>" */ | ||
22 | if (sscanf(str, "%lu,%lu,%d,%d", | ||
23 | &interval, &probability, &space, ×) < 4) { | ||
24 | printk(KERN_WARNING | ||
25 | "FAULT_INJECTION: failed to parse arguments\n"); | ||
26 | return 0; | ||
27 | } | ||
28 | |||
29 | attr->probability = probability; | ||
30 | attr->interval = interval; | ||
31 | atomic_set(&attr->times, times); | ||
32 | atomic_set(&attr->space, space); | ||
33 | |||
34 | return 1; | ||
35 | } | ||
36 | |||
37 | static void fail_dump(struct fault_attr *attr) | ||
38 | { | ||
39 | if (attr->verbose > 0) | ||
40 | printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure\n"); | ||
41 | if (attr->verbose > 1) | ||
42 | dump_stack(); | ||
43 | } | ||
44 | |||
45 | #define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0) | ||
46 | |||
47 | /* | ||
48 | * This code is stolen from failmalloc-1.0 | ||
49 | * http://www.nongnu.org/failmalloc/ | ||
50 | */ | ||
51 | |||
52 | int should_fail(struct fault_attr *attr, ssize_t size) | ||
53 | { | ||
54 | if (atomic_read(&attr->times) == 0) | ||
55 | return 0; | ||
56 | |||
57 | if (atomic_read(&attr->space) > size) { | ||
58 | atomic_sub(size, &attr->space); | ||
59 | return 0; | ||
60 | } | ||
61 | |||
62 | if (attr->interval > 1) { | ||
63 | attr->count++; | ||
64 | if (attr->count % attr->interval) | ||
65 | return 0; | ||
66 | } | ||
67 | |||
68 | if (attr->probability > random32() % 100) | ||
69 | goto fail; | ||
70 | |||
71 | return 0; | ||
72 | |||
73 | fail: | ||
74 | fail_dump(attr); | ||
75 | |||
76 | if (atomic_read(&attr->times) != -1) | ||
77 | atomic_dec_not_zero(&attr->times); | ||
78 | |||
79 | return 1; | ||
80 | } | ||
81 | |||
82 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | ||
83 | |||
84 | static void debugfs_ul_set(void *data, u64 val) | ||
85 | { | ||
86 | *(unsigned long *)data = val; | ||
87 | } | ||
88 | |||
89 | static u64 debugfs_ul_get(void *data) | ||
90 | { | ||
91 | return *(unsigned long *)data; | ||
92 | } | ||
93 | |||
94 | DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n"); | ||
95 | |||
96 | static struct dentry *debugfs_create_ul(const char *name, mode_t mode, | ||
97 | struct dentry *parent, unsigned long *value) | ||
98 | { | ||
99 | return debugfs_create_file(name, mode, parent, value, &fops_ul); | ||
100 | } | ||
101 | |||
102 | static void debugfs_atomic_t_set(void *data, u64 val) | ||
103 | { | ||
104 | atomic_set((atomic_t *)data, val); | ||
105 | } | ||
106 | |||
107 | static u64 debugfs_atomic_t_get(void *data) | ||
108 | { | ||
109 | return atomic_read((atomic_t *)data); | ||
110 | } | ||
111 | |||
112 | DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, | ||
113 | debugfs_atomic_t_set, "%lld\n"); | ||
114 | |||
115 | static struct dentry *debugfs_create_atomic_t(const char *name, mode_t mode, | ||
116 | struct dentry *parent, atomic_t *value) | ||
117 | { | ||
118 | return debugfs_create_file(name, mode, parent, value, &fops_atomic_t); | ||
119 | } | ||
120 | |||
121 | void cleanup_fault_attr_dentries(struct fault_attr *attr) | ||
122 | { | ||
123 | debugfs_remove(attr->dentries.probability_file); | ||
124 | attr->dentries.probability_file = NULL; | ||
125 | |||
126 | debugfs_remove(attr->dentries.interval_file); | ||
127 | attr->dentries.interval_file = NULL; | ||
128 | |||
129 | debugfs_remove(attr->dentries.times_file); | ||
130 | attr->dentries.times_file = NULL; | ||
131 | |||
132 | debugfs_remove(attr->dentries.space_file); | ||
133 | attr->dentries.space_file = NULL; | ||
134 | |||
135 | debugfs_remove(attr->dentries.verbose_file); | ||
136 | attr->dentries.verbose_file = NULL; | ||
137 | |||
138 | if (attr->dentries.dir) | ||
139 | WARN_ON(!simple_empty(attr->dentries.dir)); | ||
140 | |||
141 | debugfs_remove(attr->dentries.dir); | ||
142 | attr->dentries.dir = NULL; | ||
143 | } | ||
144 | |||
145 | int init_fault_attr_dentries(struct fault_attr *attr, const char *name) | ||
146 | { | ||
147 | mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; | ||
148 | struct dentry *dir; | ||
149 | |||
150 | memset(&attr->dentries, 0, sizeof(attr->dentries)); | ||
151 | |||
152 | dir = debugfs_create_dir(name, NULL); | ||
153 | if (!dir) | ||
154 | goto fail; | ||
155 | attr->dentries.dir = dir; | ||
156 | |||
157 | attr->dentries.probability_file = | ||
158 | debugfs_create_ul("probability", mode, dir, &attr->probability); | ||
159 | |||
160 | attr->dentries.interval_file = | ||
161 | debugfs_create_ul("interval", mode, dir, &attr->interval); | ||
162 | |||
163 | attr->dentries.times_file = | ||
164 | debugfs_create_atomic_t("times", mode, dir, &attr->times); | ||
165 | |||
166 | attr->dentries.space_file = | ||
167 | debugfs_create_atomic_t("space", mode, dir, &attr->space); | ||
168 | |||
169 | attr->dentries.verbose_file = | ||
170 | debugfs_create_ul("verbose", mode, dir, &attr->verbose); | ||
171 | |||
172 | if (!attr->dentries.probability_file || !attr->dentries.interval_file | ||
173 | || !attr->dentries.times_file || !attr->dentries.space_file | ||
174 | || !attr->dentries.verbose_file) | ||
175 | goto fail; | ||
176 | |||
177 | return 0; | ||
178 | fail: | ||
179 | cleanup_fault_attr_dentries(attr); | ||
180 | return -ENOMEM; | ||
181 | } | ||
182 | |||
183 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ | ||