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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/**
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
24DEFINE_SPINLOCK(oprofilefs_lock);
25
Robert Richter25ad29132008-09-05 17:12:36 +020026static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027{
Robert Richter25ad29132008-09-05 17:12:36 +020028 struct inode *inode = new_inode(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30 if (inode) {
31 inode->i_mode = mode;
32 inode->i_uid = 0;
33 inode->i_gid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 inode->i_blocks = 0;
35 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
36 }
37 return inode;
38}
39
40
41static struct super_operations s_ops = {
42 .statfs = simple_statfs,
43 .drop_inode = generic_delete_inode,
44};
45
46
Robert Richter25ad29132008-09-05 17:12:36 +020047ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
49 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
50}
51
52
53#define TMPBUFSIZE 50
54
Robert Richter25ad29132008-09-05 17:12:36 +020055ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
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
Robert Richter25ad29132008-09-05 17:12:36 +020065int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070066{
67 char tmpbuf[TMPBUFSIZE];
Jiri Kosina4dfc8962007-03-28 18:12:34 +020068 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70 if (!count)
71 return 0;
72
73 if (count > TMPBUFSIZE - 1)
74 return -EINVAL;
75
76 memset(tmpbuf, 0x0, TMPBUFSIZE);
77
78 if (copy_from_user(tmpbuf, buf, count))
79 return -EFAULT;
80
Jiri Kosina4dfc8962007-03-28 18:12:34 +020081 spin_lock_irqsave(&oprofilefs_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 *val = simple_strtoul(tmpbuf, NULL, 0);
Jiri Kosina4dfc8962007-03-28 18:12:34 +020083 spin_unlock_irqrestore(&oprofilefs_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 return 0;
85}
86
87
Robert Richter25ad29132008-09-05 17:12:36 +020088static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
Robert Richter25ad29132008-09-05 17:12:36 +020090 unsigned long *val = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 return oprofilefs_ulong_to_user(*val, buf, count, offset);
92}
93
94
Robert Richter25ad29132008-09-05 17:12:36 +020095static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
Robert Richter25ad29132008-09-05 17:12:36 +020097 unsigned long *value = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 int retval;
99
100 if (*offset)
101 return -EINVAL;
102
103 retval = oprofilefs_ulong_from_user(value, buf, count);
104
105 if (retval)
106 return retval;
107 return count;
108}
109
110
Robert Richter25ad29132008-09-05 17:12:36 +0200111static int default_open(struct inode *inode, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700113 if (inode->i_private)
114 filp->private_data = inode->i_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 return 0;
116}
117
118
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800119static const struct file_operations ulong_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 .read = ulong_read_file,
121 .write = ulong_write_file,
122 .open = default_open,
123};
124
125
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800126static const struct file_operations ulong_ro_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 .read = ulong_read_file,
128 .open = default_open,
129};
130
131
Robert Richter25ad29132008-09-05 17:12:36 +0200132static struct dentry *__oprofilefs_create_file(struct super_block *sb,
133 struct dentry *root, char const *name, const struct file_operations *fops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 int perm)
135{
Robert Richter25ad29132008-09-05 17:12:36 +0200136 struct dentry *dentry;
137 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
139 dentry = d_alloc_name(root, name);
140 if (!dentry)
141 return NULL;
142 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
143 if (!inode) {
144 dput(dentry);
145 return NULL;
146 }
147 inode->i_fop = fops;
148 d_add(dentry, inode);
149 return dentry;
150}
151
152
Robert Richter25ad29132008-09-05 17:12:36 +0200153int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root,
154 char const *name, unsigned long *val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
Robert Richter25ad29132008-09-05 17:12:36 +0200156 struct dentry *d = __oprofilefs_create_file(sb, root, name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 &ulong_fops, 0644);
158 if (!d)
159 return -EFAULT;
160
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700161 d->d_inode->i_private = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 return 0;
163}
164
165
Robert Richter25ad29132008-09-05 17:12:36 +0200166int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root,
167 char const *name, unsigned long *val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
Robert Richter25ad29132008-09-05 17:12:36 +0200169 struct dentry *d = __oprofilefs_create_file(sb, root, name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 &ulong_ro_fops, 0444);
171 if (!d)
172 return -EFAULT;
173
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700174 d->d_inode->i_private = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 return 0;
176}
177
178
Robert Richter25ad29132008-09-05 17:12:36 +0200179static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Robert Richter25ad29132008-09-05 17:12:36 +0200181 atomic_t *val = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
183}
Robert Richter6a180372008-10-16 15:01:40 +0200184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800186static const struct file_operations atomic_ro_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 .read = atomic_read_file,
188 .open = default_open,
189};
Robert Richter6a180372008-10-16 15:01:40 +0200190
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
Robert Richter25ad29132008-09-05 17:12:36 +0200192int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root,
193 char const *name, atomic_t *val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
Robert Richter25ad29132008-09-05 17:12:36 +0200195 struct dentry *d = __oprofilefs_create_file(sb, root, name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 &atomic_ro_fops, 0444);
197 if (!d)
198 return -EFAULT;
199
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700200 d->d_inode->i_private = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 return 0;
202}
203
Robert Richter6a180372008-10-16 15:01:40 +0200204
Robert Richter25ad29132008-09-05 17:12:36 +0200205int oprofilefs_create_file(struct super_block *sb, struct dentry *root,
206 char const *name, const struct file_operations *fops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
208 if (!__oprofilefs_create_file(sb, root, name, fops, 0644))
209 return -EFAULT;
210 return 0;
211}
212
213
Robert Richter25ad29132008-09-05 17:12:36 +0200214int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root,
215 char const *name, const struct file_operations *fops, int perm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
217 if (!__oprofilefs_create_file(sb, root, name, fops, perm))
218 return -EFAULT;
219 return 0;
220}
221
222
Robert Richter25ad29132008-09-05 17:12:36 +0200223struct dentry *oprofilefs_mkdir(struct super_block *sb,
224 struct dentry *root, char const *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225{
Robert Richter25ad29132008-09-05 17:12:36 +0200226 struct dentry *dentry;
227 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
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
Robert Richter25ad29132008-09-05 17:12:36 +0200244static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245{
Robert Richter25ad29132008-09-05 17:12:36 +0200246 struct inode *root_inode;
247 struct dentry *root_dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
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
David Howells454e2392006-06-23 02:02:57 -0700275static int oprofilefs_get_sb(struct file_system_type *fs_type,
276 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277{
David Howells454e2392006-06-23 02:02:57 -0700278 return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279}
280
281
282static 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
290int __init oprofilefs_register(void)
291{
292 return register_filesystem(&oprofilefs_type);
293}
294
295
296void __exit oprofilefs_unregister(void)
297{
298 unregister_filesystem(&oprofilefs_type);
299}