4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
9 * A simple filesystem for configuration and
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/oprofile.h>
17 #include <linux/pagemap.h>
18 #include <asm/uaccess.h>
22 #define OPROFILEFS_MAGIC 0x6f70726f
24 DEFINE_SPINLOCK(oprofilefs_lock);
26 static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode)
28 struct inode *inode = new_inode(sb);
32 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
38 static const struct super_operations s_ops = {
39 .statfs = simple_statfs,
40 .drop_inode = generic_delete_inode,
44 ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
46 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
52 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
54 char tmpbuf[TMPBUFSIZE];
55 size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
56 if (maxlen > TMPBUFSIZE)
58 return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
62 int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
64 char tmpbuf[TMPBUFSIZE];
70 if (count > TMPBUFSIZE - 1)
73 memset(tmpbuf, 0x0, TMPBUFSIZE);
75 if (copy_from_user(tmpbuf, buf, count))
78 spin_lock_irqsave(&oprofilefs_lock, flags);
79 *val = simple_strtoul(tmpbuf, NULL, 0);
80 spin_unlock_irqrestore(&oprofilefs_lock, flags);
85 static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
87 unsigned long *val = file->private_data;
88 return oprofilefs_ulong_to_user(*val, buf, count, offset);
92 static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
100 retval = oprofilefs_ulong_from_user(&value, buf, count);
104 retval = oprofile_set_ulong(file->private_data, value);
112 static int default_open(struct inode *inode, struct file *filp)
114 if (inode->i_private)
115 filp->private_data = inode->i_private;
120 static const struct file_operations ulong_fops = {
121 .read = ulong_read_file,
122 .write = ulong_write_file,
123 .open = default_open,
127 static const struct file_operations ulong_ro_fops = {
128 .read = ulong_read_file,
129 .open = default_open,
133 static int __oprofilefs_create_file(struct super_block *sb,
134 struct dentry *root, char const *name, const struct file_operations *fops,
135 int perm, void *priv)
137 struct dentry *dentry;
140 dentry = d_alloc_name(root, name);
143 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
149 d_add(dentry, inode);
150 dentry->d_inode->i_private = priv;
155 int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root,
156 char const *name, unsigned long *val)
158 return __oprofilefs_create_file(sb, root, name,
159 &ulong_fops, 0644, val);
163 int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root,
164 char const *name, unsigned long *val)
166 return __oprofilefs_create_file(sb, root, name,
167 &ulong_ro_fops, 0444, val);
171 static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
173 atomic_t *val = file->private_data;
174 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
178 static const struct file_operations atomic_ro_fops = {
179 .read = atomic_read_file,
180 .open = default_open,
184 int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root,
185 char const *name, atomic_t *val)
187 return __oprofilefs_create_file(sb, root, name,
188 &atomic_ro_fops, 0444, val);
192 int oprofilefs_create_file(struct super_block *sb, struct dentry *root,
193 char const *name, const struct file_operations *fops)
195 return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL);
199 int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root,
200 char const *name, const struct file_operations *fops, int perm)
202 return __oprofilefs_create_file(sb, root, name, fops, perm, NULL);
206 struct dentry *oprofilefs_mkdir(struct super_block *sb,
207 struct dentry *root, char const *name)
209 struct dentry *dentry;
212 dentry = d_alloc_name(root, name);
215 inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
220 inode->i_op = &simple_dir_inode_operations;
221 inode->i_fop = &simple_dir_operations;
222 d_add(dentry, inode);
227 static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
229 struct inode *root_inode;
230 struct dentry *root_dentry;
232 sb->s_blocksize = PAGE_CACHE_SIZE;
233 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
234 sb->s_magic = OPROFILEFS_MAGIC;
238 root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
241 root_inode->i_op = &simple_dir_inode_operations;
242 root_inode->i_fop = &simple_dir_operations;
243 root_dentry = d_alloc_root(root_inode);
249 sb->s_root = root_dentry;
251 oprofile_create_files(sb, root_dentry);
253 // FIXME: verify kill_litter_super removes our dentries
258 static int oprofilefs_get_sb(struct file_system_type *fs_type,
259 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
261 return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt);
265 static struct file_system_type oprofilefs_type = {
266 .owner = THIS_MODULE,
267 .name = "oprofilefs",
268 .get_sb = oprofilefs_get_sb,
269 .kill_sb = kill_litter_super,
273 int __init oprofilefs_register(void)
275 return register_filesystem(&oprofilefs_type);
279 void __exit oprofilefs_unregister(void)
281 unregister_filesystem(&oprofilefs_type);