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Commit | Line | Data |
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1da177e4 LT |
1 | /** |
2 | * @file oprofilefs.c | |
3 | * | |
4 | * @remark Copyright 2002 OProfile authors | |
5 | * @remark Read the file COPYING | |
6 | * | |
7 | * @author John Levon | |
8 | * | |
9 | * A simple filesystem for configuration and | |
10 | * access of oprofile. | |
11 | */ | |
12 | ||
13 | #include <linux/init.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/oprofile.h> | |
16 | #include <linux/fs.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <asm/uaccess.h> | |
19 | ||
20 | #include "oprof.h" | |
21 | ||
22 | #define OPROFILEFS_MAGIC 0x6f70726f | |
23 | ||
24 | DEFINE_SPINLOCK(oprofilefs_lock); | |
25 | ||
25ad2913 | 26 | static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode) |
1da177e4 | 27 | { |
25ad2913 | 28 | struct inode *inode = new_inode(sb); |
1da177e4 LT |
29 | |
30 | if (inode) { | |
85fe4025 | 31 | inode->i_ino = get_next_ino(); |
1da177e4 | 32 | inode->i_mode = mode; |
1da177e4 LT |
33 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
34 | } | |
35 | return inode; | |
36 | } | |
37 | ||
38 | ||
b87221de | 39 | static const struct super_operations s_ops = { |
1da177e4 LT |
40 | .statfs = simple_statfs, |
41 | .drop_inode = generic_delete_inode, | |
42 | }; | |
43 | ||
44 | ||
25ad2913 | 45 | ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset) |
1da177e4 LT |
46 | { |
47 | return simple_read_from_buffer(buf, count, offset, str, strlen(str)); | |
48 | } | |
49 | ||
50 | ||
51 | #define TMPBUFSIZE 50 | |
52 | ||
25ad2913 | 53 | ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset) |
1da177e4 LT |
54 | { |
55 | char tmpbuf[TMPBUFSIZE]; | |
56 | size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val); | |
57 | if (maxlen > TMPBUFSIZE) | |
58 | maxlen = TMPBUFSIZE; | |
59 | return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); | |
60 | } | |
61 | ||
62 | ||
25ad2913 | 63 | int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) |
1da177e4 LT |
64 | { |
65 | char tmpbuf[TMPBUFSIZE]; | |
4dfc896e | 66 | unsigned long flags; |
1da177e4 LT |
67 | |
68 | if (!count) | |
69 | return 0; | |
70 | ||
71 | if (count > TMPBUFSIZE - 1) | |
72 | return -EINVAL; | |
73 | ||
74 | memset(tmpbuf, 0x0, TMPBUFSIZE); | |
75 | ||
76 | if (copy_from_user(tmpbuf, buf, count)) | |
77 | return -EFAULT; | |
78 | ||
4dfc896e | 79 | spin_lock_irqsave(&oprofilefs_lock, flags); |
1da177e4 | 80 | *val = simple_strtoul(tmpbuf, NULL, 0); |
4dfc896e | 81 | spin_unlock_irqrestore(&oprofilefs_lock, flags); |
1da177e4 LT |
82 | return 0; |
83 | } | |
84 | ||
85 | ||
25ad2913 | 86 | static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
1da177e4 | 87 | { |
25ad2913 | 88 | unsigned long *val = file->private_data; |
1da177e4 LT |
89 | return oprofilefs_ulong_to_user(*val, buf, count, offset); |
90 | } | |
91 | ||
92 | ||
25ad2913 | 93 | static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset) |
1da177e4 | 94 | { |
7df01d96 | 95 | unsigned long value; |
1da177e4 LT |
96 | int retval; |
97 | ||
98 | if (*offset) | |
99 | return -EINVAL; | |
100 | ||
7df01d96 RR |
101 | retval = oprofilefs_ulong_from_user(&value, buf, count); |
102 | if (retval) | |
103 | return retval; | |
1da177e4 | 104 | |
7df01d96 | 105 | retval = oprofile_set_ulong(file->private_data, value); |
1da177e4 LT |
106 | if (retval) |
107 | return retval; | |
7df01d96 | 108 | |
1da177e4 LT |
109 | return count; |
110 | } | |
111 | ||
112 | ||
25ad2913 | 113 | static int default_open(struct inode *inode, struct file *filp) |
1da177e4 | 114 | { |
8e18e294 TT |
115 | if (inode->i_private) |
116 | filp->private_data = inode->i_private; | |
1da177e4 LT |
117 | return 0; |
118 | } | |
119 | ||
120 | ||
d54b1fdb | 121 | static const struct file_operations ulong_fops = { |
1da177e4 LT |
122 | .read = ulong_read_file, |
123 | .write = ulong_write_file, | |
124 | .open = default_open, | |
6038f373 | 125 | .llseek = default_llseek, |
1da177e4 LT |
126 | }; |
127 | ||
128 | ||
d54b1fdb | 129 | static const struct file_operations ulong_ro_fops = { |
1da177e4 LT |
130 | .read = ulong_read_file, |
131 | .open = default_open, | |
6038f373 | 132 | .llseek = default_llseek, |
1da177e4 LT |
133 | }; |
134 | ||
135 | ||
4fdaa7b6 | 136 | static int __oprofilefs_create_file(struct super_block *sb, |
25ad2913 | 137 | struct dentry *root, char const *name, const struct file_operations *fops, |
4fdaa7b6 | 138 | int perm, void *priv) |
1da177e4 | 139 | { |
25ad2913 RR |
140 | struct dentry *dentry; |
141 | struct inode *inode; | |
1da177e4 LT |
142 | |
143 | dentry = d_alloc_name(root, name); | |
144 | if (!dentry) | |
4fdaa7b6 | 145 | return -ENOMEM; |
1da177e4 LT |
146 | inode = oprofilefs_get_inode(sb, S_IFREG | perm); |
147 | if (!inode) { | |
148 | dput(dentry); | |
4fdaa7b6 | 149 | return -ENOMEM; |
1da177e4 LT |
150 | } |
151 | inode->i_fop = fops; | |
152 | d_add(dentry, inode); | |
4fdaa7b6 RR |
153 | dentry->d_inode->i_private = priv; |
154 | return 0; | |
1da177e4 LT |
155 | } |
156 | ||
157 | ||
25ad2913 RR |
158 | int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, |
159 | char const *name, unsigned long *val) | |
1da177e4 | 160 | { |
4fdaa7b6 RR |
161 | return __oprofilefs_create_file(sb, root, name, |
162 | &ulong_fops, 0644, val); | |
1da177e4 LT |
163 | } |
164 | ||
165 | ||
25ad2913 RR |
166 | int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root, |
167 | char const *name, unsigned long *val) | |
1da177e4 | 168 | { |
4fdaa7b6 RR |
169 | return __oprofilefs_create_file(sb, root, name, |
170 | &ulong_ro_fops, 0444, val); | |
1da177e4 LT |
171 | } |
172 | ||
173 | ||
25ad2913 | 174 | static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
1da177e4 | 175 | { |
25ad2913 | 176 | atomic_t *val = file->private_data; |
1da177e4 LT |
177 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); |
178 | } | |
6a18037d | 179 | |
1da177e4 | 180 | |
d54b1fdb | 181 | static const struct file_operations atomic_ro_fops = { |
1da177e4 LT |
182 | .read = atomic_read_file, |
183 | .open = default_open, | |
6038f373 | 184 | .llseek = default_llseek, |
1da177e4 | 185 | }; |
6a18037d | 186 | |
1da177e4 | 187 | |
25ad2913 RR |
188 | int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, |
189 | char const *name, atomic_t *val) | |
1da177e4 | 190 | { |
4fdaa7b6 RR |
191 | return __oprofilefs_create_file(sb, root, name, |
192 | &atomic_ro_fops, 0444, val); | |
1da177e4 LT |
193 | } |
194 | ||
6a18037d | 195 | |
25ad2913 RR |
196 | int oprofilefs_create_file(struct super_block *sb, struct dentry *root, |
197 | char const *name, const struct file_operations *fops) | |
1da177e4 | 198 | { |
4fdaa7b6 | 199 | return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL); |
1da177e4 LT |
200 | } |
201 | ||
202 | ||
25ad2913 RR |
203 | int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, |
204 | char const *name, const struct file_operations *fops, int perm) | |
1da177e4 | 205 | { |
4fdaa7b6 | 206 | return __oprofilefs_create_file(sb, root, name, fops, perm, NULL); |
1da177e4 LT |
207 | } |
208 | ||
209 | ||
25ad2913 RR |
210 | struct dentry *oprofilefs_mkdir(struct super_block *sb, |
211 | struct dentry *root, char const *name) | |
1da177e4 | 212 | { |
25ad2913 RR |
213 | struct dentry *dentry; |
214 | struct inode *inode; | |
1da177e4 LT |
215 | |
216 | dentry = d_alloc_name(root, name); | |
217 | if (!dentry) | |
218 | return NULL; | |
219 | inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
220 | if (!inode) { | |
221 | dput(dentry); | |
222 | return NULL; | |
223 | } | |
224 | inode->i_op = &simple_dir_inode_operations; | |
225 | inode->i_fop = &simple_dir_operations; | |
226 | d_add(dentry, inode); | |
227 | return dentry; | |
228 | } | |
229 | ||
230 | ||
25ad2913 | 231 | static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) |
1da177e4 | 232 | { |
25ad2913 RR |
233 | struct inode *root_inode; |
234 | struct dentry *root_dentry; | |
1da177e4 LT |
235 | |
236 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
237 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
238 | sb->s_magic = OPROFILEFS_MAGIC; | |
239 | sb->s_op = &s_ops; | |
240 | sb->s_time_gran = 1; | |
241 | ||
242 | root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
243 | if (!root_inode) | |
244 | return -ENOMEM; | |
245 | root_inode->i_op = &simple_dir_inode_operations; | |
246 | root_inode->i_fop = &simple_dir_operations; | |
247 | root_dentry = d_alloc_root(root_inode); | |
248 | if (!root_dentry) { | |
249 | iput(root_inode); | |
250 | return -ENOMEM; | |
251 | } | |
252 | ||
253 | sb->s_root = root_dentry; | |
254 | ||
255 | oprofile_create_files(sb, root_dentry); | |
256 | ||
257 | // FIXME: verify kill_litter_super removes our dentries | |
258 | return 0; | |
259 | } | |
260 | ||
261 | ||
fc14f2fe AV |
262 | static struct dentry *oprofilefs_mount(struct file_system_type *fs_type, |
263 | int flags, const char *dev_name, void *data) | |
1da177e4 | 264 | { |
fc14f2fe | 265 | return mount_single(fs_type, flags, data, oprofilefs_fill_super); |
1da177e4 LT |
266 | } |
267 | ||
268 | ||
269 | static struct file_system_type oprofilefs_type = { | |
270 | .owner = THIS_MODULE, | |
271 | .name = "oprofilefs", | |
fc14f2fe | 272 | .mount = oprofilefs_mount, |
1da177e4 LT |
273 | .kill_sb = kill_litter_super, |
274 | }; | |
275 | ||
276 | ||
277 | int __init oprofilefs_register(void) | |
278 | { | |
279 | return register_filesystem(&oprofilefs_type); | |
280 | } | |
281 | ||
282 | ||
283 | void __exit oprofilefs_unregister(void) | |
284 | { | |
285 | unregister_filesystem(&oprofilefs_type); | |
286 | } |