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 | 25ad2913 | 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 | 25ad2913 | 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; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 33 | } |
| 34 | return inode; |
| 35 | } |
| 36 | |
| 37 | |
| 38 | static struct super_operations s_ops = { |
| 39 | .statfs = simple_statfs, |
| 40 | .drop_inode = generic_delete_inode, |
| 41 | }; |
| 42 | |
| 43 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 44 | 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] | 45 | { |
| 46 | return simple_read_from_buffer(buf, count, offset, str, strlen(str)); |
| 47 | } |
| 48 | |
| 49 | |
| 50 | #define TMPBUFSIZE 50 |
| 51 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 52 | 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] | 53 | { |
| 54 | char tmpbuf[TMPBUFSIZE]; |
| 55 | size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val); |
| 56 | if (maxlen > TMPBUFSIZE) |
| 57 | maxlen = TMPBUFSIZE; |
| 58 | return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); |
| 59 | } |
| 60 | |
| 61 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 62 | 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] | 63 | { |
| 64 | char tmpbuf[TMPBUFSIZE]; |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 65 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | |
| 67 | if (!count) |
| 68 | return 0; |
| 69 | |
| 70 | if (count > TMPBUFSIZE - 1) |
| 71 | return -EINVAL; |
| 72 | |
| 73 | memset(tmpbuf, 0x0, TMPBUFSIZE); |
| 74 | |
| 75 | if (copy_from_user(tmpbuf, buf, count)) |
| 76 | return -EFAULT; |
| 77 | |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 78 | spin_lock_irqsave(&oprofilefs_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | *val = simple_strtoul(tmpbuf, NULL, 0); |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 80 | spin_unlock_irqrestore(&oprofilefs_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 85 | 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] | 86 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 87 | unsigned long *val = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | return oprofilefs_ulong_to_user(*val, buf, count, offset); |
| 89 | } |
| 90 | |
| 91 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 92 | 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] | 93 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 94 | unsigned long *value = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | int retval; |
| 96 | |
| 97 | if (*offset) |
| 98 | return -EINVAL; |
| 99 | |
| 100 | retval = oprofilefs_ulong_from_user(value, buf, count); |
| 101 | |
| 102 | if (retval) |
| 103 | return retval; |
| 104 | return count; |
| 105 | } |
| 106 | |
| 107 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 108 | static int default_open(struct inode *inode, struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | { |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 110 | if (inode->i_private) |
| 111 | filp->private_data = inode->i_private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 116 | static const struct file_operations ulong_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | .read = ulong_read_file, |
| 118 | .write = ulong_write_file, |
| 119 | .open = default_open, |
| 120 | }; |
| 121 | |
| 122 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 123 | static const struct file_operations ulong_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | .read = ulong_read_file, |
| 125 | .open = default_open, |
| 126 | }; |
| 127 | |
| 128 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 129 | static struct dentry *__oprofilefs_create_file(struct super_block *sb, |
| 130 | struct dentry *root, char const *name, const struct file_operations *fops, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | int perm) |
| 132 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 133 | struct dentry *dentry; |
| 134 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | |
| 136 | dentry = d_alloc_name(root, name); |
| 137 | if (!dentry) |
| 138 | return NULL; |
| 139 | inode = oprofilefs_get_inode(sb, S_IFREG | perm); |
| 140 | if (!inode) { |
| 141 | dput(dentry); |
| 142 | return NULL; |
| 143 | } |
| 144 | inode->i_fop = fops; |
| 145 | d_add(dentry, inode); |
| 146 | return dentry; |
| 147 | } |
| 148 | |
| 149 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 150 | int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, |
| 151 | char const *name, unsigned long *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 153 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | &ulong_fops, 0644); |
| 155 | if (!d) |
| 156 | return -EFAULT; |
| 157 | |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 158 | d->d_inode->i_private = val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 163 | int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root, |
| 164 | char const *name, unsigned long *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 166 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | &ulong_ro_fops, 0444); |
| 168 | if (!d) |
| 169 | return -EFAULT; |
| 170 | |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 171 | d->d_inode->i_private = val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 176 | 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] | 177 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 178 | atomic_t *val = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); |
| 180 | } |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 181 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 183 | static const struct file_operations atomic_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | .read = atomic_read_file, |
| 185 | .open = default_open, |
| 186 | }; |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 187 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 189 | int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, |
| 190 | char const *name, atomic_t *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 192 | struct dentry *d = __oprofilefs_create_file(sb, root, name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | &atomic_ro_fops, 0444); |
| 194 | if (!d) |
| 195 | return -EFAULT; |
| 196 | |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 197 | d->d_inode->i_private = val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | return 0; |
| 199 | } |
| 200 | |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 201 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 202 | int oprofilefs_create_file(struct super_block *sb, struct dentry *root, |
| 203 | char const *name, const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | { |
| 205 | if (!__oprofilefs_create_file(sb, root, name, fops, 0644)) |
| 206 | return -EFAULT; |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 211 | int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, |
| 212 | char const *name, const struct file_operations *fops, int perm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | { |
| 214 | if (!__oprofilefs_create_file(sb, root, name, fops, perm)) |
| 215 | return -EFAULT; |
| 216 | return 0; |
| 217 | } |
| 218 | |
| 219 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 220 | struct dentry *oprofilefs_mkdir(struct super_block *sb, |
| 221 | struct dentry *root, char const *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 223 | struct dentry *dentry; |
| 224 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
| 226 | dentry = d_alloc_name(root, name); |
| 227 | if (!dentry) |
| 228 | return NULL; |
| 229 | inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); |
| 230 | if (!inode) { |
| 231 | dput(dentry); |
| 232 | return NULL; |
| 233 | } |
| 234 | inode->i_op = &simple_dir_inode_operations; |
| 235 | inode->i_fop = &simple_dir_operations; |
| 236 | d_add(dentry, inode); |
| 237 | return dentry; |
| 238 | } |
| 239 | |
| 240 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 241 | 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] | 242 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 243 | struct inode *root_inode; |
| 244 | struct dentry *root_dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | |
| 246 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 247 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 248 | sb->s_magic = OPROFILEFS_MAGIC; |
| 249 | sb->s_op = &s_ops; |
| 250 | sb->s_time_gran = 1; |
| 251 | |
| 252 | root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); |
| 253 | if (!root_inode) |
| 254 | return -ENOMEM; |
| 255 | root_inode->i_op = &simple_dir_inode_operations; |
| 256 | root_inode->i_fop = &simple_dir_operations; |
| 257 | root_dentry = d_alloc_root(root_inode); |
| 258 | if (!root_dentry) { |
| 259 | iput(root_inode); |
| 260 | return -ENOMEM; |
| 261 | } |
| 262 | |
| 263 | sb->s_root = root_dentry; |
| 264 | |
| 265 | oprofile_create_files(sb, root_dentry); |
| 266 | |
| 267 | // FIXME: verify kill_litter_super removes our dentries |
| 268 | return 0; |
| 269 | } |
| 270 | |
| 271 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 272 | static int oprofilefs_get_sb(struct file_system_type *fs_type, |
| 273 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 275 | return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | } |
| 277 | |
| 278 | |
| 279 | static struct file_system_type oprofilefs_type = { |
| 280 | .owner = THIS_MODULE, |
| 281 | .name = "oprofilefs", |
| 282 | .get_sb = oprofilefs_get_sb, |
| 283 | .kill_sb = kill_litter_super, |
| 284 | }; |
| 285 | |
| 286 | |
| 287 | int __init oprofilefs_register(void) |
| 288 | { |
| 289 | return register_filesystem(&oprofilefs_type); |
| 290 | } |
| 291 | |
| 292 | |
| 293 | void __exit oprofilefs_unregister(void) |
| 294 | { |
| 295 | unregister_filesystem(&oprofilefs_type); |
| 296 | } |