Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /** |
| 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 | |
| 24 | DEFINE_SPINLOCK(oprofilefs_lock); |
| 25 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 26 | static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 28 | struct inode *inode = new_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | if (inode) { |
| 31 | inode->i_mode = mode; |
| 32 | inode->i_uid = 0; |
| 33 | inode->i_gid = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | inode->i_blocks = 0; |
| 35 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 36 | } |
| 37 | return inode; |
| 38 | } |
| 39 | |
| 40 | |
| 41 | static struct super_operations s_ops = { |
| 42 | .statfs = simple_statfs, |
| 43 | .drop_inode = generic_delete_inode, |
| 44 | }; |
| 45 | |
| 46 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 47 | ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | { |
| 49 | return simple_read_from_buffer(buf, count, offset, str, strlen(str)); |
| 50 | } |
| 51 | |
| 52 | |
| 53 | #define TMPBUFSIZE 50 |
| 54 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 55 | ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | { |
| 57 | char tmpbuf[TMPBUFSIZE]; |
| 58 | size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val); |
| 59 | if (maxlen > TMPBUFSIZE) |
| 60 | maxlen = TMPBUFSIZE; |
| 61 | return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); |
| 62 | } |
| 63 | |
| 64 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 65 | int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | { |
| 67 | char tmpbuf[TMPBUFSIZE]; |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 68 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | |
| 70 | if (!count) |
| 71 | return 0; |
| 72 | |
| 73 | if (count > TMPBUFSIZE - 1) |
| 74 | return -EINVAL; |
| 75 | |
| 76 | memset(tmpbuf, 0x0, TMPBUFSIZE); |
| 77 | |
| 78 | if (copy_from_user(tmpbuf, buf, count)) |
| 79 | return -EFAULT; |
| 80 | |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 81 | spin_lock_irqsave(&oprofilefs_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | *val = simple_strtoul(tmpbuf, NULL, 0); |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 83 | spin_unlock_irqrestore(&oprofilefs_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 88 | static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 90 | unsigned long *val = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | return oprofilefs_ulong_to_user(*val, buf, count, offset); |
| 92 | } |
| 93 | |
| 94 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 95 | static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 97 | unsigned long *value = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | int retval; |
| 99 | |
| 100 | if (*offset) |
| 101 | return -EINVAL; |
| 102 | |
| 103 | retval = oprofilefs_ulong_from_user(value, buf, count); |
| 104 | |
| 105 | if (retval) |
| 106 | return retval; |
| 107 | return count; |
| 108 | } |
| 109 | |
| 110 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 111 | static int default_open(struct inode *inode, struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | { |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 113 | if (inode->i_private) |
| 114 | filp->private_data = inode->i_private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 119 | static const struct file_operations ulong_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | .read = ulong_read_file, |
| 121 | .write = ulong_write_file, |
| 122 | .open = default_open, |
| 123 | }; |
| 124 | |
| 125 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 126 | static const struct file_operations ulong_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | .read = ulong_read_file, |
| 128 | .open = default_open, |
| 129 | }; |
| 130 | |
| 131 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 132 | static struct dentry *__oprofilefs_create_file(struct super_block *sb, |
| 133 | struct dentry *root, char const *name, const struct file_operations *fops, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | int perm) |
| 135 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 136 | struct dentry *dentry; |
| 137 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
| 139 | dentry = d_alloc_name(root, name); |
| 140 | if (!dentry) |
| 141 | return NULL; |
| 142 | inode = oprofilefs_get_inode(sb, S_IFREG | perm); |
| 143 | if (!inode) { |
| 144 | dput(dentry); |
| 145 | return NULL; |
| 146 | } |
| 147 | inode->i_fop = fops; |
| 148 | d_add(dentry, inode); |
| 149 | return dentry; |
| 150 | } |
| 151 | |
| 152 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 153 | int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, |
| 154 | char const *name, unsigned long *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 156 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | &ulong_fops, 0644); |
| 158 | if (!d) |
| 159 | return -EFAULT; |
| 160 | |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 161 | d->d_inode->i_private = val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 166 | int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root, |
| 167 | char const *name, unsigned long *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 169 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | &ulong_ro_fops, 0444); |
| 171 | if (!d) |
| 172 | return -EFAULT; |
| 173 | |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 174 | d->d_inode->i_private = val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 179 | static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 181 | atomic_t *val = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); |
| 183 | } |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 184 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 186 | static const struct file_operations atomic_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | .read = atomic_read_file, |
| 188 | .open = default_open, |
| 189 | }; |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 190 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 192 | int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, |
| 193 | char const *name, atomic_t *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 195 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | &atomic_ro_fops, 0444); |
| 197 | if (!d) |
| 198 | return -EFAULT; |
| 199 | |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 200 | d->d_inode->i_private = val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | return 0; |
| 202 | } |
| 203 | |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 204 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 205 | int oprofilefs_create_file(struct super_block *sb, struct dentry *root, |
| 206 | char const *name, const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | { |
| 208 | if (!__oprofilefs_create_file(sb, root, name, fops, 0644)) |
| 209 | return -EFAULT; |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 214 | int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, |
| 215 | char const *name, const struct file_operations *fops, int perm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | { |
| 217 | if (!__oprofilefs_create_file(sb, root, name, fops, perm)) |
| 218 | return -EFAULT; |
| 219 | return 0; |
| 220 | } |
| 221 | |
| 222 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 223 | struct dentry *oprofilefs_mkdir(struct super_block *sb, |
| 224 | struct dentry *root, char const *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 226 | struct dentry *dentry; |
| 227 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | |
| 229 | dentry = d_alloc_name(root, name); |
| 230 | if (!dentry) |
| 231 | return NULL; |
| 232 | inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); |
| 233 | if (!inode) { |
| 234 | dput(dentry); |
| 235 | return NULL; |
| 236 | } |
| 237 | inode->i_op = &simple_dir_inode_operations; |
| 238 | inode->i_fop = &simple_dir_operations; |
| 239 | d_add(dentry, inode); |
| 240 | return dentry; |
| 241 | } |
| 242 | |
| 243 | |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 244 | static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | { |
Robert Richter | 25ad291 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 246 | struct inode *root_inode; |
| 247 | struct dentry *root_dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | |
| 249 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 250 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 251 | sb->s_magic = OPROFILEFS_MAGIC; |
| 252 | sb->s_op = &s_ops; |
| 253 | sb->s_time_gran = 1; |
| 254 | |
| 255 | root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); |
| 256 | if (!root_inode) |
| 257 | return -ENOMEM; |
| 258 | root_inode->i_op = &simple_dir_inode_operations; |
| 259 | root_inode->i_fop = &simple_dir_operations; |
| 260 | root_dentry = d_alloc_root(root_inode); |
| 261 | if (!root_dentry) { |
| 262 | iput(root_inode); |
| 263 | return -ENOMEM; |
| 264 | } |
| 265 | |
| 266 | sb->s_root = root_dentry; |
| 267 | |
| 268 | oprofile_create_files(sb, root_dentry); |
| 269 | |
| 270 | // FIXME: verify kill_litter_super removes our dentries |
| 271 | return 0; |
| 272 | } |
| 273 | |
| 274 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 275 | static int oprofilefs_get_sb(struct file_system_type *fs_type, |
| 276 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 278 | return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | } |
| 280 | |
| 281 | |
| 282 | static struct file_system_type oprofilefs_type = { |
| 283 | .owner = THIS_MODULE, |
| 284 | .name = "oprofilefs", |
| 285 | .get_sb = oprofilefs_get_sb, |
| 286 | .kill_sb = kill_litter_super, |
| 287 | }; |
| 288 | |
| 289 | |
| 290 | int __init oprofilefs_register(void) |
| 291 | { |
| 292 | return register_filesystem(&oprofilefs_type); |
| 293 | } |
| 294 | |
| 295 | |
| 296 | void __exit oprofilefs_unregister(void) |
| 297 | { |
| 298 | unregister_filesystem(&oprofilefs_type); |
| 299 | } |