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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) { | |
31 | inode->i_mode = mode; | |
1da177e4 LT |
32 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
33 | } | |
34 | return inode; | |
35 | } | |
36 | ||
37 | ||
b87221de | 38 | static const struct super_operations s_ops = { |
1da177e4 LT |
39 | .statfs = simple_statfs, |
40 | .drop_inode = generic_delete_inode, | |
41 | }; | |
42 | ||
43 | ||
25ad2913 | 44 | ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset) |
1da177e4 LT |
45 | { |
46 | return simple_read_from_buffer(buf, count, offset, str, strlen(str)); | |
47 | } | |
48 | ||
49 | ||
50 | #define TMPBUFSIZE 50 | |
51 | ||
25ad2913 | 52 | ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset) |
1da177e4 LT |
53 | { |
54 | char tmpbuf[TMPBUFSIZE]; | |
55 | size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val); | |
56 | if (maxlen > TMPBUFSIZE) | |
57 | maxlen = TMPBUFSIZE; | |
58 | return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); | |
59 | } | |
60 | ||
61 | ||
25ad2913 | 62 | int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) |
1da177e4 LT |
63 | { |
64 | char tmpbuf[TMPBUFSIZE]; | |
4dfc896e | 65 | unsigned long flags; |
1da177e4 LT |
66 | |
67 | if (!count) | |
68 | return 0; | |
69 | ||
70 | if (count > TMPBUFSIZE - 1) | |
71 | return -EINVAL; | |
72 | ||
73 | memset(tmpbuf, 0x0, TMPBUFSIZE); | |
74 | ||
75 | if (copy_from_user(tmpbuf, buf, count)) | |
76 | return -EFAULT; | |
77 | ||
4dfc896e | 78 | spin_lock_irqsave(&oprofilefs_lock, flags); |
1da177e4 | 79 | *val = simple_strtoul(tmpbuf, NULL, 0); |
4dfc896e | 80 | spin_unlock_irqrestore(&oprofilefs_lock, flags); |
1da177e4 LT |
81 | return 0; |
82 | } | |
83 | ||
84 | ||
25ad2913 | 85 | static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
1da177e4 | 86 | { |
25ad2913 | 87 | unsigned long *val = file->private_data; |
1da177e4 LT |
88 | return oprofilefs_ulong_to_user(*val, buf, count, offset); |
89 | } | |
90 | ||
91 | ||
25ad2913 | 92 | static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset) |
1da177e4 | 93 | { |
25ad2913 | 94 | unsigned long *value = file->private_data; |
1da177e4 LT |
95 | int retval; |
96 | ||
97 | if (*offset) | |
98 | return -EINVAL; | |
99 | ||
100 | retval = oprofilefs_ulong_from_user(value, buf, count); | |
101 | ||
102 | if (retval) | |
103 | return retval; | |
104 | return count; | |
105 | } | |
106 | ||
107 | ||
25ad2913 | 108 | static int default_open(struct inode *inode, struct file *filp) |
1da177e4 | 109 | { |
8e18e294 TT |
110 | if (inode->i_private) |
111 | filp->private_data = inode->i_private; | |
1da177e4 LT |
112 | return 0; |
113 | } | |
114 | ||
115 | ||
d54b1fdb | 116 | static const struct file_operations ulong_fops = { |
1da177e4 LT |
117 | .read = ulong_read_file, |
118 | .write = ulong_write_file, | |
119 | .open = default_open, | |
6038f373 | 120 | .llseek = default_llseek, |
1da177e4 LT |
121 | }; |
122 | ||
123 | ||
d54b1fdb | 124 | static const struct file_operations ulong_ro_fops = { |
1da177e4 LT |
125 | .read = ulong_read_file, |
126 | .open = default_open, | |
6038f373 | 127 | .llseek = default_llseek, |
1da177e4 LT |
128 | }; |
129 | ||
130 | ||
25ad2913 RR |
131 | static struct dentry *__oprofilefs_create_file(struct super_block *sb, |
132 | struct dentry *root, char const *name, const struct file_operations *fops, | |
1da177e4 LT |
133 | int perm) |
134 | { | |
25ad2913 RR |
135 | struct dentry *dentry; |
136 | struct inode *inode; | |
1da177e4 LT |
137 | |
138 | dentry = d_alloc_name(root, name); | |
139 | if (!dentry) | |
140 | return NULL; | |
141 | inode = oprofilefs_get_inode(sb, S_IFREG | perm); | |
142 | if (!inode) { | |
143 | dput(dentry); | |
144 | return NULL; | |
145 | } | |
146 | inode->i_fop = fops; | |
147 | d_add(dentry, inode); | |
148 | return dentry; | |
149 | } | |
150 | ||
151 | ||
25ad2913 RR |
152 | int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, |
153 | char const *name, unsigned long *val) | |
1da177e4 | 154 | { |
25ad2913 | 155 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
1da177e4 LT |
156 | &ulong_fops, 0644); |
157 | if (!d) | |
158 | return -EFAULT; | |
159 | ||
8e18e294 | 160 | d->d_inode->i_private = val; |
1da177e4 LT |
161 | return 0; |
162 | } | |
163 | ||
164 | ||
25ad2913 RR |
165 | int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root, |
166 | char const *name, unsigned long *val) | |
1da177e4 | 167 | { |
25ad2913 | 168 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
1da177e4 LT |
169 | &ulong_ro_fops, 0444); |
170 | if (!d) | |
171 | return -EFAULT; | |
172 | ||
8e18e294 | 173 | d->d_inode->i_private = val; |
1da177e4 LT |
174 | return 0; |
175 | } | |
176 | ||
177 | ||
25ad2913 | 178 | static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
1da177e4 | 179 | { |
25ad2913 | 180 | atomic_t *val = file->private_data; |
1da177e4 LT |
181 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); |
182 | } | |
6a18037d | 183 | |
1da177e4 | 184 | |
d54b1fdb | 185 | static const struct file_operations atomic_ro_fops = { |
1da177e4 LT |
186 | .read = atomic_read_file, |
187 | .open = default_open, | |
6038f373 | 188 | .llseek = default_llseek, |
1da177e4 | 189 | }; |
6a18037d | 190 | |
1da177e4 | 191 | |
25ad2913 RR |
192 | int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, |
193 | char const *name, atomic_t *val) | |
1da177e4 | 194 | { |
25ad2913 | 195 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
1da177e4 LT |
196 | &atomic_ro_fops, 0444); |
197 | if (!d) | |
198 | return -EFAULT; | |
199 | ||
8e18e294 | 200 | d->d_inode->i_private = val; |
1da177e4 LT |
201 | return 0; |
202 | } | |
203 | ||
6a18037d | 204 | |
25ad2913 RR |
205 | int oprofilefs_create_file(struct super_block *sb, struct dentry *root, |
206 | char const *name, const struct file_operations *fops) | |
1da177e4 LT |
207 | { |
208 | if (!__oprofilefs_create_file(sb, root, name, fops, 0644)) | |
209 | return -EFAULT; | |
210 | return 0; | |
211 | } | |
212 | ||
213 | ||
25ad2913 RR |
214 | int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, |
215 | char const *name, const struct file_operations *fops, int perm) | |
1da177e4 LT |
216 | { |
217 | if (!__oprofilefs_create_file(sb, root, name, fops, perm)) | |
218 | return -EFAULT; | |
219 | return 0; | |
220 | } | |
221 | ||
222 | ||
25ad2913 RR |
223 | struct dentry *oprofilefs_mkdir(struct super_block *sb, |
224 | struct dentry *root, char const *name) | |
1da177e4 | 225 | { |
25ad2913 RR |
226 | struct dentry *dentry; |
227 | struct inode *inode; | |
1da177e4 LT |
228 | |
229 | dentry = d_alloc_name(root, name); | |
230 | if (!dentry) | |
231 | return NULL; | |
232 | inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
233 | if (!inode) { | |
234 | dput(dentry); | |
235 | return NULL; | |
236 | } | |
237 | inode->i_op = &simple_dir_inode_operations; | |
238 | inode->i_fop = &simple_dir_operations; | |
239 | d_add(dentry, inode); | |
240 | return dentry; | |
241 | } | |
242 | ||
243 | ||
25ad2913 | 244 | static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) |
1da177e4 | 245 | { |
25ad2913 RR |
246 | struct inode *root_inode; |
247 | struct dentry *root_dentry; | |
1da177e4 LT |
248 | |
249 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
250 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
251 | sb->s_magic = OPROFILEFS_MAGIC; | |
252 | sb->s_op = &s_ops; | |
253 | sb->s_time_gran = 1; | |
254 | ||
255 | root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
256 | if (!root_inode) | |
257 | return -ENOMEM; | |
258 | root_inode->i_op = &simple_dir_inode_operations; | |
259 | root_inode->i_fop = &simple_dir_operations; | |
260 | root_dentry = d_alloc_root(root_inode); | |
261 | if (!root_dentry) { | |
262 | iput(root_inode); | |
263 | return -ENOMEM; | |
264 | } | |
265 | ||
266 | sb->s_root = root_dentry; | |
267 | ||
268 | oprofile_create_files(sb, root_dentry); | |
269 | ||
270 | // FIXME: verify kill_litter_super removes our dentries | |
271 | return 0; | |
272 | } | |
273 | ||
274 | ||
454e2398 DH |
275 | static int oprofilefs_get_sb(struct file_system_type *fs_type, |
276 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 277 | { |
454e2398 | 278 | return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt); |
1da177e4 LT |
279 | } |
280 | ||
281 | ||
282 | static struct file_system_type oprofilefs_type = { | |
283 | .owner = THIS_MODULE, | |
284 | .name = "oprofilefs", | |
285 | .get_sb = oprofilefs_get_sb, | |
286 | .kill_sb = kill_litter_super, | |
287 | }; | |
288 | ||
289 | ||
290 | int __init oprofilefs_register(void) | |
291 | { | |
292 | return register_filesystem(&oprofilefs_type); | |
293 | } | |
294 | ||
295 | ||
296 | void __exit oprofilefs_unregister(void) | |
297 | { | |
298 | unregister_filesystem(&oprofilefs_type); | |
299 | } |