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 spinlock_t oprofilefs_lock = SPIN_LOCK_UNLOCKED;
26 static struct inode * oprofilefs_get_inode(struct super_block * sb, int mode)
28 struct inode * inode = new_inode(sb);
34 inode->i_blksize = PAGE_CACHE_SIZE;
36 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
42 static struct super_operations s_ops = {
43 .statfs = simple_statfs,
44 .drop_inode = generic_delete_inode,
48 ssize_t oprofilefs_str_to_user(char const * str, char __user * buf, size_t count, loff_t * offset)
50 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
56 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t count, loff_t * offset)
58 char tmpbuf[TMPBUFSIZE];
59 size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
60 if (maxlen > TMPBUFSIZE)
62 return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
66 int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count)
68 char tmpbuf[TMPBUFSIZE];
73 if (count > TMPBUFSIZE - 1)
76 memset(tmpbuf, 0x0, TMPBUFSIZE);
78 if (copy_from_user(tmpbuf, buf, count))
81 spin_lock(&oprofilefs_lock);
82 *val = simple_strtoul(tmpbuf, NULL, 0);
83 spin_unlock(&oprofilefs_lock);
88 static ssize_t ulong_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset)
90 unsigned long * val = file->private_data;
91 return oprofilefs_ulong_to_user(*val, buf, count, offset);
95 static ssize_t ulong_write_file(struct file * file, char const __user * buf, size_t count, loff_t * offset)
97 unsigned long * value = file->private_data;
103 retval = oprofilefs_ulong_from_user(value, buf, count);
111 static int default_open(struct inode * inode, struct file * filp)
113 if (inode->u.generic_ip)
114 filp->private_data = inode->u.generic_ip;
119 static struct file_operations ulong_fops = {
120 .read = ulong_read_file,
121 .write = ulong_write_file,
122 .open = default_open,
126 static struct file_operations ulong_ro_fops = {
127 .read = ulong_read_file,
128 .open = default_open,
132 static struct dentry * __oprofilefs_create_file(struct super_block * sb,
133 struct dentry * root, char const * name, struct file_operations * fops,
136 struct dentry * dentry;
137 struct inode * inode;
140 qname.len = strlen(name);
141 qname.hash = full_name_hash(qname.name, qname.len);
142 dentry = d_alloc(root, &qname);
145 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
151 d_add(dentry, inode);
156 int oprofilefs_create_ulong(struct super_block * sb, struct dentry * root,
157 char const * name, unsigned long * val)
159 struct dentry * d = __oprofilefs_create_file(sb, root, name,
164 d->d_inode->u.generic_ip = val;
169 int oprofilefs_create_ro_ulong(struct super_block * sb, struct dentry * root,
170 char const * name, unsigned long * val)
172 struct dentry * d = __oprofilefs_create_file(sb, root, name,
173 &ulong_ro_fops, 0444);
177 d->d_inode->u.generic_ip = val;
182 static ssize_t atomic_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset)
184 atomic_t * val = file->private_data;
185 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
189 static struct file_operations atomic_ro_fops = {
190 .read = atomic_read_file,
191 .open = default_open,
195 int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root,
196 char const * name, atomic_t * val)
198 struct dentry * d = __oprofilefs_create_file(sb, root, name,
199 &atomic_ro_fops, 0444);
203 d->d_inode->u.generic_ip = val;
208 int oprofilefs_create_file(struct super_block * sb, struct dentry * root,
209 char const * name, struct file_operations * fops)
211 if (!__oprofilefs_create_file(sb, root, name, fops, 0644))
217 int oprofilefs_create_file_perm(struct super_block * sb, struct dentry * root,
218 char const * name, struct file_operations * fops, int perm)
220 if (!__oprofilefs_create_file(sb, root, name, fops, perm))
226 struct dentry * oprofilefs_mkdir(struct super_block * sb,
227 struct dentry * root, char const * name)
229 struct dentry * dentry;
230 struct inode * inode;
233 qname.len = strlen(name);
234 qname.hash = full_name_hash(qname.name, qname.len);
235 dentry = d_alloc(root, &qname);
238 inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
243 inode->i_op = &simple_dir_inode_operations;
244 inode->i_fop = &simple_dir_operations;
245 d_add(dentry, inode);
250 static int oprofilefs_fill_super(struct super_block * sb, void * data, int silent)
252 struct inode * root_inode;
253 struct dentry * root_dentry;
255 sb->s_blocksize = PAGE_CACHE_SIZE;
256 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
257 sb->s_magic = OPROFILEFS_MAGIC;
260 root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
263 root_inode->i_op = &simple_dir_inode_operations;
264 root_inode->i_fop = &simple_dir_operations;
265 root_dentry = d_alloc_root(root_inode);
271 sb->s_root = root_dentry;
273 oprofile_create_files(sb, root_dentry);
275 // FIXME: verify kill_litter_super removes our dentries
280 static struct super_block *oprofilefs_get_sb(struct file_system_type *fs_type,
281 int flags, const char *dev_name, void *data)
283 return get_sb_single(fs_type, flags, data, oprofilefs_fill_super);
287 static struct file_system_type oprofilefs_type = {
288 .owner = THIS_MODULE,
289 .name = "oprofilefs",
290 .get_sb = oprofilefs_get_sb,
291 .kill_sb = kill_litter_super,
295 int __init oprofilefs_register(void)
297 return register_filesystem(&oprofilefs_type);
301 void __exit oprofilefs_unregister(void)
303 unregister_filesystem(&oprofilefs_type);