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 | ||
26 | static struct inode * oprofilefs_get_inode(struct super_block * sb, int mode) | |
27 | { | |
28 | struct inode * inode = new_inode(sb); | |
29 | ||
30 | if (inode) { | |
31 | inode->i_mode = mode; | |
32 | inode->i_uid = 0; | |
33 | inode->i_gid = 0; | |
1da177e4 LT |
34 | inode->i_blocks = 0; |
35 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
36 | } | |
37 | return inode; | |
38 | } | |
39 | ||
40 | ||
41 | static struct super_operations s_ops = { | |
42 | .statfs = simple_statfs, | |
43 | .drop_inode = generic_delete_inode, | |
44 | }; | |
45 | ||
46 | ||
47 | ssize_t oprofilefs_str_to_user(char const * str, char __user * buf, size_t count, loff_t * offset) | |
48 | { | |
49 | return simple_read_from_buffer(buf, count, offset, str, strlen(str)); | |
50 | } | |
51 | ||
52 | ||
53 | #define TMPBUFSIZE 50 | |
54 | ||
55 | ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t count, loff_t * offset) | |
56 | { | |
57 | char tmpbuf[TMPBUFSIZE]; | |
58 | size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val); | |
59 | if (maxlen > TMPBUFSIZE) | |
60 | maxlen = TMPBUFSIZE; | |
61 | return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); | |
62 | } | |
63 | ||
64 | ||
65 | int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count) | |
66 | { | |
67 | char tmpbuf[TMPBUFSIZE]; | |
68 | ||
69 | if (!count) | |
70 | return 0; | |
71 | ||
72 | if (count > TMPBUFSIZE - 1) | |
73 | return -EINVAL; | |
74 | ||
75 | memset(tmpbuf, 0x0, TMPBUFSIZE); | |
76 | ||
77 | if (copy_from_user(tmpbuf, buf, count)) | |
78 | return -EFAULT; | |
79 | ||
80 | spin_lock(&oprofilefs_lock); | |
81 | *val = simple_strtoul(tmpbuf, NULL, 0); | |
82 | spin_unlock(&oprofilefs_lock); | |
83 | return 0; | |
84 | } | |
85 | ||
86 | ||
87 | static ssize_t ulong_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset) | |
88 | { | |
89 | unsigned long * val = file->private_data; | |
90 | return oprofilefs_ulong_to_user(*val, buf, count, offset); | |
91 | } | |
92 | ||
93 | ||
94 | static ssize_t ulong_write_file(struct file * file, char const __user * buf, size_t count, loff_t * offset) | |
95 | { | |
96 | unsigned long * value = file->private_data; | |
97 | int retval; | |
98 | ||
99 | if (*offset) | |
100 | return -EINVAL; | |
101 | ||
102 | retval = oprofilefs_ulong_from_user(value, buf, count); | |
103 | ||
104 | if (retval) | |
105 | return retval; | |
106 | return count; | |
107 | } | |
108 | ||
109 | ||
110 | static int default_open(struct inode * inode, struct file * filp) | |
111 | { | |
8e18e294 TT |
112 | if (inode->i_private) |
113 | filp->private_data = inode->i_private; | |
1da177e4 LT |
114 | return 0; |
115 | } | |
116 | ||
117 | ||
118 | static struct file_operations ulong_fops = { | |
119 | .read = ulong_read_file, | |
120 | .write = ulong_write_file, | |
121 | .open = default_open, | |
122 | }; | |
123 | ||
124 | ||
125 | static struct file_operations ulong_ro_fops = { | |
126 | .read = ulong_read_file, | |
127 | .open = default_open, | |
128 | }; | |
129 | ||
130 | ||
131 | static struct dentry * __oprofilefs_create_file(struct super_block * sb, | |
99ac48f5 | 132 | struct dentry * root, char const * name, const struct file_operations * fops, |
1da177e4 LT |
133 | int perm) |
134 | { | |
135 | struct dentry * dentry; | |
136 | struct inode * inode; | |
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 | ||
152 | int oprofilefs_create_ulong(struct super_block * sb, struct dentry * root, | |
153 | char const * name, unsigned long * val) | |
154 | { | |
155 | struct dentry * d = __oprofilefs_create_file(sb, root, name, | |
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 | ||
165 | int oprofilefs_create_ro_ulong(struct super_block * sb, struct dentry * root, | |
166 | char const * name, unsigned long * val) | |
167 | { | |
168 | struct dentry * d = __oprofilefs_create_file(sb, root, name, | |
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 | ||
178 | static ssize_t atomic_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset) | |
179 | { | |
180 | atomic_t * val = file->private_data; | |
181 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); | |
182 | } | |
183 | ||
184 | ||
185 | static struct file_operations atomic_ro_fops = { | |
186 | .read = atomic_read_file, | |
187 | .open = default_open, | |
188 | }; | |
189 | ||
190 | ||
191 | int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root, | |
192 | char const * name, atomic_t * val) | |
193 | { | |
194 | struct dentry * d = __oprofilefs_create_file(sb, root, name, | |
195 | &atomic_ro_fops, 0444); | |
196 | if (!d) | |
197 | return -EFAULT; | |
198 | ||
8e18e294 | 199 | d->d_inode->i_private = val; |
1da177e4 LT |
200 | return 0; |
201 | } | |
202 | ||
203 | ||
204 | int oprofilefs_create_file(struct super_block * sb, struct dentry * root, | |
99ac48f5 | 205 | char const * name, const struct file_operations * fops) |
1da177e4 LT |
206 | { |
207 | if (!__oprofilefs_create_file(sb, root, name, fops, 0644)) | |
208 | return -EFAULT; | |
209 | return 0; | |
210 | } | |
211 | ||
212 | ||
213 | int oprofilefs_create_file_perm(struct super_block * sb, struct dentry * root, | |
99ac48f5 | 214 | char const * name, const struct file_operations * fops, int perm) |
1da177e4 LT |
215 | { |
216 | if (!__oprofilefs_create_file(sb, root, name, fops, perm)) | |
217 | return -EFAULT; | |
218 | return 0; | |
219 | } | |
220 | ||
221 | ||
222 | struct dentry * oprofilefs_mkdir(struct super_block * sb, | |
223 | struct dentry * root, char const * name) | |
224 | { | |
225 | struct dentry * dentry; | |
226 | struct inode * inode; | |
227 | ||
228 | dentry = d_alloc_name(root, name); | |
229 | if (!dentry) | |
230 | return NULL; | |
231 | inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
232 | if (!inode) { | |
233 | dput(dentry); | |
234 | return NULL; | |
235 | } | |
236 | inode->i_op = &simple_dir_inode_operations; | |
237 | inode->i_fop = &simple_dir_operations; | |
238 | d_add(dentry, inode); | |
239 | return dentry; | |
240 | } | |
241 | ||
242 | ||
243 | static int oprofilefs_fill_super(struct super_block * sb, void * data, int silent) | |
244 | { | |
245 | struct inode * root_inode; | |
246 | struct dentry * root_dentry; | |
247 | ||
248 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
249 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
250 | sb->s_magic = OPROFILEFS_MAGIC; | |
251 | sb->s_op = &s_ops; | |
252 | sb->s_time_gran = 1; | |
253 | ||
254 | root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); | |
255 | if (!root_inode) | |
256 | return -ENOMEM; | |
257 | root_inode->i_op = &simple_dir_inode_operations; | |
258 | root_inode->i_fop = &simple_dir_operations; | |
259 | root_dentry = d_alloc_root(root_inode); | |
260 | if (!root_dentry) { | |
261 | iput(root_inode); | |
262 | return -ENOMEM; | |
263 | } | |
264 | ||
265 | sb->s_root = root_dentry; | |
266 | ||
267 | oprofile_create_files(sb, root_dentry); | |
268 | ||
269 | // FIXME: verify kill_litter_super removes our dentries | |
270 | return 0; | |
271 | } | |
272 | ||
273 | ||
454e2398 DH |
274 | static int oprofilefs_get_sb(struct file_system_type *fs_type, |
275 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 276 | { |
454e2398 | 277 | return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt); |
1da177e4 LT |
278 | } |
279 | ||
280 | ||
281 | static struct file_system_type oprofilefs_type = { | |
282 | .owner = THIS_MODULE, | |
283 | .name = "oprofilefs", | |
284 | .get_sb = oprofilefs_get_sb, | |
285 | .kill_sb = kill_litter_super, | |
286 | }; | |
287 | ||
288 | ||
289 | int __init oprofilefs_register(void) | |
290 | { | |
291 | return register_filesystem(&oprofilefs_type); | |
292 | } | |
293 | ||
294 | ||
295 | void __exit oprofilefs_unregister(void) | |
296 | { | |
297 | unregister_filesystem(&oprofilefs_type); | |
298 | } |