Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus
[linux-btrfs-devel.git] / drivers / oprofile / oprofilefs.c
blobe9ff6f7770be23a046cd5ce22b8fd504794b3907
1 /**
2 * @file oprofilefs.c
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
7 * @author John Levon
9 * A simple filesystem for configuration and
10 * access of oprofile.
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>
20 #include "oprof.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);
30 if (inode) {
31 inode->i_ino = get_next_ino();
32 inode->i_mode = mode;
33 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
35 return inode;
39 static const struct super_operations s_ops = {
40 .statfs = simple_statfs,
41 .drop_inode = generic_delete_inode,
45 ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
47 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
51 #define TMPBUFSIZE 50
53 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
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);
63 int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
65 char tmpbuf[TMPBUFSIZE];
66 unsigned long flags;
68 if (!count)
69 return 0;
71 if (count > TMPBUFSIZE - 1)
72 return -EINVAL;
74 memset(tmpbuf, 0x0, TMPBUFSIZE);
76 if (copy_from_user(tmpbuf, buf, count))
77 return -EFAULT;
79 spin_lock_irqsave(&oprofilefs_lock, flags);
80 *val = simple_strtoul(tmpbuf, NULL, 0);
81 spin_unlock_irqrestore(&oprofilefs_lock, flags);
82 return 0;
86 static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
88 unsigned long *val = file->private_data;
89 return oprofilefs_ulong_to_user(*val, buf, count, offset);
93 static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
95 unsigned long value;
96 int retval;
98 if (*offset)
99 return -EINVAL;
101 retval = oprofilefs_ulong_from_user(&value, buf, count);
102 if (retval)
103 return retval;
105 retval = oprofile_set_ulong(file->private_data, value);
106 if (retval)
107 return retval;
109 return count;
113 static int default_open(struct inode *inode, struct file *filp)
115 if (inode->i_private)
116 filp->private_data = inode->i_private;
117 return 0;
121 static const struct file_operations ulong_fops = {
122 .read = ulong_read_file,
123 .write = ulong_write_file,
124 .open = default_open,
125 .llseek = default_llseek,
129 static const struct file_operations ulong_ro_fops = {
130 .read = ulong_read_file,
131 .open = default_open,
132 .llseek = default_llseek,
136 static int __oprofilefs_create_file(struct super_block *sb,
137 struct dentry *root, char const *name, const struct file_operations *fops,
138 int perm, void *priv)
140 struct dentry *dentry;
141 struct inode *inode;
143 dentry = d_alloc_name(root, name);
144 if (!dentry)
145 return -ENOMEM;
146 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
147 if (!inode) {
148 dput(dentry);
149 return -ENOMEM;
151 inode->i_fop = fops;
152 d_add(dentry, inode);
153 dentry->d_inode->i_private = priv;
154 return 0;
158 int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root,
159 char const *name, unsigned long *val)
161 return __oprofilefs_create_file(sb, root, name,
162 &ulong_fops, 0644, val);
166 int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root,
167 char const *name, unsigned long *val)
169 return __oprofilefs_create_file(sb, root, name,
170 &ulong_ro_fops, 0444, val);
174 static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
176 atomic_t *val = file->private_data;
177 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
181 static const struct file_operations atomic_ro_fops = {
182 .read = atomic_read_file,
183 .open = default_open,
184 .llseek = default_llseek,
188 int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root,
189 char const *name, atomic_t *val)
191 return __oprofilefs_create_file(sb, root, name,
192 &atomic_ro_fops, 0444, val);
196 int oprofilefs_create_file(struct super_block *sb, struct dentry *root,
197 char const *name, const struct file_operations *fops)
199 return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL);
203 int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root,
204 char const *name, const struct file_operations *fops, int perm)
206 return __oprofilefs_create_file(sb, root, name, fops, perm, NULL);
210 struct dentry *oprofilefs_mkdir(struct super_block *sb,
211 struct dentry *root, char const *name)
213 struct dentry *dentry;
214 struct inode *inode;
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;
224 inode->i_op = &simple_dir_inode_operations;
225 inode->i_fop = &simple_dir_operations;
226 d_add(dentry, inode);
227 return dentry;
231 static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
233 struct inode *root_inode;
234 struct dentry *root_dentry;
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;
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;
253 sb->s_root = root_dentry;
255 oprofile_create_files(sb, root_dentry);
257 // FIXME: verify kill_litter_super removes our dentries
258 return 0;
262 static struct dentry *oprofilefs_mount(struct file_system_type *fs_type,
263 int flags, const char *dev_name, void *data)
265 return mount_single(fs_type, flags, data, oprofilefs_fill_super);
269 static struct file_system_type oprofilefs_type = {
270 .owner = THIS_MODULE,
271 .name = "oprofilefs",
272 .mount = oprofilefs_mount,
273 .kill_sb = kill_litter_super,
277 int __init oprofilefs_register(void)
279 return register_filesystem(&oprofilefs_type);
283 void __exit oprofilefs_unregister(void)
285 unregister_filesystem(&oprofilefs_type);