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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, | |
120 | }; | |
121 | ||
122 | ||
d54b1fdb | 123 | static const struct file_operations ulong_ro_fops = { |
1da177e4 LT |
124 | .read = ulong_read_file, |
125 | .open = default_open, | |
126 | }; | |
127 | ||
128 | ||
25ad2913 RR |
129 | static struct dentry *__oprofilefs_create_file(struct super_block *sb, |
130 | struct dentry *root, char const *name, const struct file_operations *fops, | |
1da177e4 LT |
131 | int perm) |
132 | { | |
25ad2913 RR |
133 | struct dentry *dentry; |
134 | struct inode *inode; | |
1da177e4 LT |
135 | |
136 | dentry = d_alloc_name(root, name); | |
137 | if (!dentry) | |
138 | return NULL; | |
139 | inode = oprofilefs_get_inode(sb, S_IFREG | perm); | |
140 | if (!inode) { | |
141 | dput(dentry); | |
142 | return NULL; | |
143 | } | |
144 | inode->i_fop = fops; | |
145 | d_add(dentry, inode); | |
146 | return dentry; | |
147 | } | |
148 | ||
149 | ||
25ad2913 RR |
150 | int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, |
151 | char const *name, unsigned long *val) | |
1da177e4 | 152 | { |
25ad2913 | 153 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
1da177e4 LT |
154 | &ulong_fops, 0644); |
155 | if (!d) | |
156 | return -EFAULT; | |
157 | ||
8e18e294 | 158 | d->d_inode->i_private = val; |
1da177e4 LT |
159 | return 0; |
160 | } | |
161 | ||
162 | ||
25ad2913 RR |
163 | int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root, |
164 | char const *name, unsigned long *val) | |
1da177e4 | 165 | { |
25ad2913 | 166 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
1da177e4 LT |
167 | &ulong_ro_fops, 0444); |
168 | if (!d) | |
169 | return -EFAULT; | |
170 | ||
8e18e294 | 171 | d->d_inode->i_private = val; |
1da177e4 LT |
172 | return 0; |
173 | } | |
174 | ||
175 | ||
25ad2913 | 176 | static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
1da177e4 | 177 | { |
25ad2913 | 178 | atomic_t *val = file->private_data; |
1da177e4 LT |
179 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); |
180 | } | |
6a18037d | 181 | |
1da177e4 | 182 | |
d54b1fdb | 183 | static const struct file_operations atomic_ro_fops = { |
1da177e4 LT |
184 | .read = atomic_read_file, |
185 | .open = default_open, | |
186 | }; | |
6a18037d | 187 | |
1da177e4 | 188 | |
25ad2913 RR |
189 | int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, |
190 | char const *name, atomic_t *val) | |
1da177e4 | 191 | { |
25ad2913 | 192 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
1da177e4 LT |
193 | &atomic_ro_fops, 0444); |
194 | if (!d) | |
195 | return -EFAULT; | |
196 | ||
8e18e294 | 197 | d->d_inode->i_private = val; |
1da177e4 LT |
198 | return 0; |
199 | } | |
200 | ||
6a18037d | 201 | |
25ad2913 RR |
202 | int oprofilefs_create_file(struct super_block *sb, struct dentry *root, |
203 | char const *name, const struct file_operations *fops) | |
1da177e4 LT |
204 | { |
205 | if (!__oprofilefs_create_file(sb, root, name, fops, 0644)) | |
206 | return -EFAULT; | |
207 | return 0; | |
208 | } | |
209 | ||
210 | ||
25ad2913 RR |
211 | int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, |
212 | char const *name, const struct file_operations *fops, int perm) | |
1da177e4 LT |
213 | { |
214 | if (!__oprofilefs_create_file(sb, root, name, fops, perm)) | |
215 | return -EFAULT; | |
216 | return 0; | |
217 | } | |
218 | ||
219 | ||
25ad2913 RR |
220 | struct dentry *oprofilefs_mkdir(struct super_block *sb, |
221 | struct dentry *root, char const *name) | |
1da177e4 | 222 | { |
25ad2913 RR |
223 | struct dentry *dentry; |
224 | struct inode *inode; | |
1da177e4 LT |
225 | |
226 | dentry = d_alloc_name(root, name); | |
227 | if (!dentry) | |
228 | return NULL; | |
229 | inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
230 | if (!inode) { | |
231 | dput(dentry); | |
232 | return NULL; | |
233 | } | |
234 | inode->i_op = &simple_dir_inode_operations; | |
235 | inode->i_fop = &simple_dir_operations; | |
236 | d_add(dentry, inode); | |
237 | return dentry; | |
238 | } | |
239 | ||
240 | ||
25ad2913 | 241 | static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) |
1da177e4 | 242 | { |
25ad2913 RR |
243 | struct inode *root_inode; |
244 | struct dentry *root_dentry; | |
1da177e4 LT |
245 | |
246 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
247 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
248 | sb->s_magic = OPROFILEFS_MAGIC; | |
249 | sb->s_op = &s_ops; | |
250 | sb->s_time_gran = 1; | |
251 | ||
252 | root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
253 | if (!root_inode) | |
254 | return -ENOMEM; | |
255 | root_inode->i_op = &simple_dir_inode_operations; | |
256 | root_inode->i_fop = &simple_dir_operations; | |
257 | root_dentry = d_alloc_root(root_inode); | |
258 | if (!root_dentry) { | |
259 | iput(root_inode); | |
260 | return -ENOMEM; | |
261 | } | |
262 | ||
263 | sb->s_root = root_dentry; | |
264 | ||
265 | oprofile_create_files(sb, root_dentry); | |
266 | ||
267 | // FIXME: verify kill_litter_super removes our dentries | |
268 | return 0; | |
269 | } | |
270 | ||
271 | ||
454e2398 DH |
272 | static int oprofilefs_get_sb(struct file_system_type *fs_type, |
273 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 274 | { |
454e2398 | 275 | return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt); |
1da177e4 LT |
276 | } |
277 | ||
278 | ||
279 | static struct file_system_type oprofilefs_type = { | |
280 | .owner = THIS_MODULE, | |
281 | .name = "oprofilefs", | |
282 | .get_sb = oprofilefs_get_sb, | |
283 | .kill_sb = kill_litter_super, | |
284 | }; | |
285 | ||
286 | ||
287 | int __init oprofilefs_register(void) | |
288 | { | |
289 | return register_filesystem(&oprofilefs_type); | |
290 | } | |
291 | ||
292 | ||
293 | void __exit oprofilefs_unregister(void) | |
294 | { | |
295 | unregister_filesystem(&oprofilefs_type); | |
296 | } |