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)
94 unsigned long *value = file->private_data;
100 retval = oprofilefs_ulong_from_user(value, buf, count);
108 static int default_open(struct inode *inode, struct file *filp)
110 if (inode->i_private)
111 filp->private_data = inode->i_private;
116 static const struct file_operations ulong_fops = {
117 .read = ulong_read_file,
118 .write = ulong_write_file,
119 .open = default_open,
123 static const struct file_operations ulong_ro_fops = {
124 .read = ulong_read_file,
125 .open = default_open,
129 static int __oprofilefs_create_file(struct super_block *sb,
130 struct dentry *root, char const *name, const struct file_operations *fops,
131 int perm, void *priv)
133 struct dentry *dentry;
136 dentry = d_alloc_name(root, name);
139 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
145 d_add(dentry, inode);
146 dentry->d_inode->i_private = priv;
151 int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root,
152 char const *name, unsigned long *val)
154 return __oprofilefs_create_file(sb, root, name,
155 &ulong_fops, 0644, val);
159 int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root,
160 char const *name, unsigned long *val)
162 return __oprofilefs_create_file(sb, root, name,
163 &ulong_ro_fops, 0444, val);
167 static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
169 atomic_t *val = file->private_data;
170 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
174 static const struct file_operations atomic_ro_fops = {
175 .read = atomic_read_file,
176 .open = default_open,
180 int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root,
181 char const *name, atomic_t *val)
183 return __oprofilefs_create_file(sb, root, name,
184 &atomic_ro_fops, 0444, val);
188 int oprofilefs_create_file(struct super_block *sb, struct dentry *root,
189 char const *name, const struct file_operations *fops)
191 return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL);
195 int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root,
196 char const *name, const struct file_operations *fops, int perm)
198 return __oprofilefs_create_file(sb, root, name, fops, perm, NULL);
202 struct dentry *oprofilefs_mkdir(struct super_block *sb,
203 struct dentry *root, char const *name)
205 struct dentry *dentry;
208 dentry = d_alloc_name(root, name);
211 inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
216 inode->i_op = &simple_dir_inode_operations;
217 inode->i_fop = &simple_dir_operations;
218 d_add(dentry, inode);
223 static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
225 struct inode *root_inode;
226 struct dentry *root_dentry;
228 sb->s_blocksize = PAGE_CACHE_SIZE;
229 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
230 sb->s_magic = OPROFILEFS_MAGIC;
234 root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
237 root_inode->i_op = &simple_dir_inode_operations;
238 root_inode->i_fop = &simple_dir_operations;
239 root_dentry = d_alloc_root(root_inode);
245 sb->s_root = root_dentry;
247 oprofile_create_files(sb, root_dentry);
249 // FIXME: verify kill_litter_super removes our dentries
254 static int oprofilefs_get_sb(struct file_system_type *fs_type,
255 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
257 return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt);
261 static struct file_system_type oprofilefs_type = {
262 .owner = THIS_MODULE,
263 .name = "oprofilefs",
264 .get_sb = oprofilefs_get_sb,
265 .kill_sb = kill_litter_super,
269 int __init oprofilefs_register(void)
271 return register_filesystem(&oprofilefs_type);
275 void __exit oprofilefs_unregister(void)
277 unregister_filesystem(&oprofilefs_type);