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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) {
Christoph Hellwig85fe4022010-10-23 11:19:54 -040031 inode->i_ino = get_next_ino();
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 inode->i_mode = mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
34 }
35 return inode;
36}
37
38
Alexey Dobriyanb87221d2009-09-21 17:01:09 -070039static const struct super_operations s_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 .statfs = simple_statfs,
41 .drop_inode = generic_delete_inode,
42};
43
44
Robert Richter25ad29132008-09-05 17:12:36 +020045ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070046{
47 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
48}
49
50
51#define TMPBUFSIZE 50
52
Robert Richter25ad29132008-09-05 17:12:36 +020053ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054{
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
Robert Richter25ad29132008-09-05 17:12:36 +020063int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070064{
65 char tmpbuf[TMPBUFSIZE];
Jiri Kosina4dfc8962007-03-28 18:12:34 +020066 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
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
Jiri Kosina4dfc8962007-03-28 18:12:34 +020079 spin_lock_irqsave(&oprofilefs_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 *val = simple_strtoul(tmpbuf, NULL, 0);
Jiri Kosina4dfc8962007-03-28 18:12:34 +020081 spin_unlock_irqrestore(&oprofilefs_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 return 0;
83}
84
85
Robert Richter25ad29132008-09-05 17:12:36 +020086static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
Robert Richter25ad29132008-09-05 17:12:36 +020088 unsigned long *val = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 return oprofilefs_ulong_to_user(*val, buf, count, offset);
90}
91
92
Robert Richter25ad29132008-09-05 17:12:36 +020093static 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 -070094{
Robert Richter7df01d92010-10-04 21:09:36 +020095 unsigned long value;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 int retval;
97
98 if (*offset)
99 return -EINVAL;
100
Robert Richter7df01d92010-10-04 21:09:36 +0200101 retval = oprofilefs_ulong_from_user(&value, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 if (retval)
103 return retval;
Robert Richter7df01d92010-10-04 21:09:36 +0200104
105 retval = oprofile_set_ulong(file->private_data, value);
106 if (retval)
107 return retval;
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 return count;
110}
111
112
Robert Richter25ad29132008-09-05 17:12:36 +0200113static int default_open(struct inode *inode, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700115 if (inode->i_private)
116 filp->private_data = inode->i_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 return 0;
118}
119
120
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800121static const struct file_operations ulong_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 .read = ulong_read_file,
123 .write = ulong_write_file,
124 .open = default_open,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200125 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126};
127
128
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800129static const struct file_operations ulong_ro_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 .read = ulong_read_file,
131 .open = default_open,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200132 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133};
134
135
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200136static int __oprofilefs_create_file(struct super_block *sb,
Robert Richter25ad29132008-09-05 17:12:36 +0200137 struct dentry *root, char const *name, const struct file_operations *fops,
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200138 int perm, void *priv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
Robert Richter25ad29132008-09-05 17:12:36 +0200140 struct dentry *dentry;
141 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 dentry = d_alloc_name(root, name);
144 if (!dentry)
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200145 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
147 if (!inode) {
148 dput(dentry);
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200149 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 }
151 inode->i_fop = fops;
152 d_add(dentry, inode);
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200153 dentry->d_inode->i_private = priv;
154 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
157
Robert Richter25ad29132008-09-05 17:12:36 +0200158int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root,
159 char const *name, unsigned long *val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160{
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200161 return __oprofilefs_create_file(sb, root, name,
162 &ulong_fops, 0644, val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
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 Richter4fdaa7b2010-08-19 10:50:26 +0200169 return __oprofilefs_create_file(sb, root, name,
170 &ulong_ro_fops, 0444, val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171}
172
173
Robert Richter25ad29132008-09-05 17:12:36 +0200174static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175{
Robert Richter25ad29132008-09-05 17:12:36 +0200176 atomic_t *val = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
178}
Robert Richter6a180372008-10-16 15:01:40 +0200179
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800181static const struct file_operations atomic_ro_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 .read = atomic_read_file,
183 .open = default_open,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200184 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185};
Robert Richter6a180372008-10-16 15:01:40 +0200186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
Robert Richter25ad29132008-09-05 17:12:36 +0200188int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root,
189 char const *name, atomic_t *val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190{
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200191 return __oprofilefs_create_file(sb, root, name,
192 &atomic_ro_fops, 0444, val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193}
194
Robert Richter6a180372008-10-16 15:01:40 +0200195
Robert Richter25ad29132008-09-05 17:12:36 +0200196int oprofilefs_create_file(struct super_block *sb, struct dentry *root,
197 char const *name, const struct file_operations *fops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198{
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200199 return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200}
201
202
Robert Richter25ad29132008-09-05 17:12:36 +0200203int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root,
204 char const *name, const struct file_operations *fops, int perm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205{
Robert Richter4fdaa7b2010-08-19 10:50:26 +0200206 return __oprofilefs_create_file(sb, root, name, fops, perm, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207}
208
209
Robert Richter25ad29132008-09-05 17:12:36 +0200210struct dentry *oprofilefs_mkdir(struct super_block *sb,
211 struct dentry *root, char const *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212{
Robert Richter25ad29132008-09-05 17:12:36 +0200213 struct dentry *dentry;
214 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
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
Robert Richter25ad29132008-09-05 17:12:36 +0200231static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232{
Robert Richter25ad29132008-09-05 17:12:36 +0200233 struct inode *root_inode;
234 struct dentry *root_dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
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
Al Virofc14f2f2010-07-25 01:48:30 +0400262static struct dentry *oprofilefs_mount(struct file_system_type *fs_type,
263 int flags, const char *dev_name, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Al Virofc14f2f2010-07-25 01:48:30 +0400265 return mount_single(fs_type, flags, data, oprofilefs_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266}
267
268
269static struct file_system_type oprofilefs_type = {
270 .owner = THIS_MODULE,
271 .name = "oprofilefs",
Al Virofc14f2f2010-07-25 01:48:30 +0400272 .mount = oprofilefs_mount,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 .kill_sb = kill_litter_super,
274};
275
276
277int __init oprofilefs_register(void)
278{
279 return register_filesystem(&oprofilefs_type);
280}
281
282
283void __exit oprofilefs_unregister(void)
284{
285 unregister_filesystem(&oprofilefs_type);
286}