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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - lib/fault-inject.c
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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>
7 #include <linux/module.h>
8 #include <linux/fault-inject.h>
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.
14 int __init
setup_fault_attr(struct fault_attr
*attr
, char *str
)
16 unsigned long probability
;
17 unsigned long interval
;
21 /* "<interval>,<probability>,<space>,<times>" */
22 if (sscanf(str
, "%lu,%lu,%d,%d",
23 &interval
, &probability
, &space
, ×
) < 4) {
25 "FAULT_INJECTION: failed to parse arguments\n");
29 attr
->probability
= probability
;
30 attr
->interval
= interval
;
31 atomic_set(&attr
->times
, times
);
32 atomic_set(&attr
->space
, space
);
37 static void fail_dump(struct fault_attr
*attr
)
39 if (attr
->verbose
> 0)
40 printk(KERN_NOTICE
"FAULT_INJECTION: forcing a failure\n");
41 if (attr
->verbose
> 1)
45 #define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0)
48 * This code is stolen from failmalloc-1.0
49 * http://www.nongnu.org/failmalloc/
52 int should_fail(struct fault_attr
*attr
, ssize_t size
)
54 if (atomic_read(&attr
->times
) == 0)
57 if (atomic_read(&attr
->space
) > size
) {
58 atomic_sub(size
, &attr
->space
);
62 if (attr
->interval
> 1) {
64 if (attr
->count
% attr
->interval
)
68 if (attr
->probability
> random32() % 100)
76 if (atomic_read(&attr
->times
) != -1)
77 atomic_dec_not_zero(&attr
->times
);
82 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
84 static void debugfs_ul_set(void *data
, u64 val
)
86 *(unsigned long *)data
= val
;
89 static u64
debugfs_ul_get(void *data
)
91 return *(unsigned long *)data
;
94 DEFINE_SIMPLE_ATTRIBUTE(fops_ul
, debugfs_ul_get
, debugfs_ul_set
, "%llu\n");
96 static struct dentry
*debugfs_create_ul(const char *name
, mode_t mode
,
97 struct dentry
*parent
, unsigned long *value
)
99 return debugfs_create_file(name
, mode
, parent
, value
, &fops_ul
);
102 static void debugfs_atomic_t_set(void *data
, u64 val
)
104 atomic_set((atomic_t
*)data
, val
);
107 static u64
debugfs_atomic_t_get(void *data
)
109 return atomic_read((atomic_t
*)data
);
112 DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t
, debugfs_atomic_t_get
,
113 debugfs_atomic_t_set
, "%lld\n");
115 static struct dentry
*debugfs_create_atomic_t(const char *name
, mode_t mode
,
116 struct dentry
*parent
, atomic_t
*value
)
118 return debugfs_create_file(name
, mode
, parent
, value
, &fops_atomic_t
);
121 void cleanup_fault_attr_dentries(struct fault_attr
*attr
)
123 debugfs_remove(attr
->dentries
.probability_file
);
124 attr
->dentries
.probability_file
= NULL
;
126 debugfs_remove(attr
->dentries
.interval_file
);
127 attr
->dentries
.interval_file
= NULL
;
129 debugfs_remove(attr
->dentries
.times_file
);
130 attr
->dentries
.times_file
= NULL
;
132 debugfs_remove(attr
->dentries
.space_file
);
133 attr
->dentries
.space_file
= NULL
;
135 debugfs_remove(attr
->dentries
.verbose_file
);
136 attr
->dentries
.verbose_file
= NULL
;
138 if (attr
->dentries
.dir
)
139 WARN_ON(!simple_empty(attr
->dentries
.dir
));
141 debugfs_remove(attr
->dentries
.dir
);
142 attr
->dentries
.dir
= NULL
;
145 int init_fault_attr_dentries(struct fault_attr
*attr
, const char *name
)
147 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
150 memset(&attr
->dentries
, 0, sizeof(attr
->dentries
));
152 dir
= debugfs_create_dir(name
, NULL
);
155 attr
->dentries
.dir
= dir
;
157 attr
->dentries
.probability_file
=
158 debugfs_create_ul("probability", mode
, dir
, &attr
->probability
);
160 attr
->dentries
.interval_file
=
161 debugfs_create_ul("interval", mode
, dir
, &attr
->interval
);
163 attr
->dentries
.times_file
=
164 debugfs_create_atomic_t("times", mode
, dir
, &attr
->times
);
166 attr
->dentries
.space_file
=
167 debugfs_create_atomic_t("space", mode
, dir
, &attr
->space
);
169 attr
->dentries
.verbose_file
=
170 debugfs_create_ul("verbose", mode
, dir
, &attr
->verbose
);
172 if (!attr
->dentries
.probability_file
|| !attr
->dentries
.interval_file
173 || !attr
->dentries
.times_file
|| !attr
->dentries
.space_file
174 || !attr
->dentries
.verbose_file
)
179 cleanup_fault_attr_dentries(attr
);
183 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */