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 | |
Thomas Gleixner | 2d21a29 | 2009-07-25 16:18:34 +0200 | [diff] [blame] | 24 | DEFINE_RAW_SPINLOCK(oprofilefs_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 31 | inode->i_ino = get_next_ino(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | inode->i_mode = mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 34 | } |
| 35 | return inode; |
| 36 | } |
| 37 | |
| 38 | |
Alexey Dobriyan | b87221d | 2009-09-21 17:01:09 -0700 | [diff] [blame] | 39 | static const struct super_operations s_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | .statfs = simple_statfs, |
| 41 | .drop_inode = generic_delete_inode, |
| 42 | }; |
| 43 | |
| 44 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 45 | 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] | 46 | { |
| 47 | return simple_read_from_buffer(buf, count, offset, str, strlen(str)); |
| 48 | } |
| 49 | |
| 50 | |
| 51 | #define TMPBUFSIZE 50 |
| 52 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 53 | 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] | 54 | { |
| 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); |
| 60 | } |
| 61 | |
| 62 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 63 | 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] | 64 | { |
| 65 | char tmpbuf[TMPBUFSIZE]; |
Jiri Kosina | 4dfc896 | 2007-03-28 18:12:34 +0200 | [diff] [blame] | 66 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | |
| 68 | if (!count) |
| 69 | return 0; |
| 70 | |
| 71 | if (count > TMPBUFSIZE - 1) |
| 72 | return -EINVAL; |
| 73 | |
| 74 | memset(tmpbuf, 0x0, TMPBUFSIZE); |
| 75 | |
| 76 | if (copy_from_user(tmpbuf, buf, count)) |
| 77 | return -EFAULT; |
| 78 | |
Thomas Gleixner | 2d21a29 | 2009-07-25 16:18:34 +0200 | [diff] [blame] | 79 | raw_spin_lock_irqsave(&oprofilefs_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | *val = simple_strtoul(tmpbuf, NULL, 0); |
Thomas Gleixner | 2d21a29 | 2009-07-25 16:18:34 +0200 | [diff] [blame] | 81 | raw_spin_unlock_irqrestore(&oprofilefs_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 86 | 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] | 87 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 88 | unsigned long *val = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | return oprofilefs_ulong_to_user(*val, buf, count, offset); |
| 90 | } |
| 91 | |
| 92 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 93 | 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] | 94 | { |
Robert Richter | 7df01d9 | 2010-10-04 21:09:36 +0200 | [diff] [blame] | 95 | unsigned long value; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | int retval; |
| 97 | |
| 98 | if (*offset) |
| 99 | return -EINVAL; |
| 100 | |
Robert Richter | 7df01d9 | 2010-10-04 21:09:36 +0200 | [diff] [blame] | 101 | retval = oprofilefs_ulong_from_user(&value, buf, count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | if (retval) |
| 103 | return retval; |
Robert Richter | 7df01d9 | 2010-10-04 21:09:36 +0200 | [diff] [blame] | 104 | |
| 105 | retval = oprofile_set_ulong(file->private_data, value); |
| 106 | if (retval) |
| 107 | return retval; |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | return count; |
| 110 | } |
| 111 | |
| 112 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 113 | static int default_open(struct inode *inode, struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | { |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 115 | if (inode->i_private) |
| 116 | filp->private_data = inode->i_private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 121 | static const struct file_operations ulong_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | .read = ulong_read_file, |
| 123 | .write = ulong_write_file, |
| 124 | .open = default_open, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 125 | .llseek = default_llseek, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | }; |
| 127 | |
| 128 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 129 | static const struct file_operations ulong_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | .read = ulong_read_file, |
| 131 | .open = default_open, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 132 | .llseek = default_llseek, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | }; |
| 134 | |
| 135 | |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 136 | static int __oprofilefs_create_file(struct super_block *sb, |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 137 | struct dentry *root, char const *name, const struct file_operations *fops, |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 138 | int perm, void *priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 140 | struct dentry *dentry; |
| 141 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
| 143 | dentry = d_alloc_name(root, name); |
| 144 | if (!dentry) |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 145 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | inode = oprofilefs_get_inode(sb, S_IFREG | perm); |
| 147 | if (!inode) { |
| 148 | dput(dentry); |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 149 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | } |
| 151 | inode->i_fop = fops; |
| 152 | d_add(dentry, inode); |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 153 | dentry->d_inode->i_private = priv; |
| 154 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | } |
| 156 | |
| 157 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 158 | int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, |
| 159 | char const *name, unsigned long *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | { |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 161 | return __oprofilefs_create_file(sb, root, name, |
| 162 | &ulong_fops, 0644, val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | } |
| 164 | |
| 165 | |
Robert Richter | 25ad2913 | 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 | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 169 | return __oprofilefs_create_file(sb, root, name, |
| 170 | &ulong_ro_fops, 0444, val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | } |
| 172 | |
| 173 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 174 | 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] | 175 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 176 | atomic_t *val = file->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); |
| 178 | } |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 179 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | |
Arjan van de Ven | d54b1fd | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 181 | static const struct file_operations atomic_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | .read = atomic_read_file, |
| 183 | .open = default_open, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 184 | .llseek = default_llseek, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | }; |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 186 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 188 | int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, |
| 189 | char const *name, atomic_t *val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | { |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 191 | return __oprofilefs_create_file(sb, root, name, |
| 192 | &atomic_ro_fops, 0444, val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | } |
| 194 | |
Robert Richter | 6a18037 | 2008-10-16 15:01:40 +0200 | [diff] [blame] | 195 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 196 | int oprofilefs_create_file(struct super_block *sb, struct dentry *root, |
| 197 | char const *name, const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 199 | return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | } |
| 201 | |
| 202 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 203 | int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, |
| 204 | char const *name, const struct file_operations *fops, int perm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
Robert Richter | 4fdaa7b | 2010-08-19 10:50:26 +0200 | [diff] [blame] | 206 | return __oprofilefs_create_file(sb, root, name, fops, perm, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | } |
| 208 | |
| 209 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 210 | struct dentry *oprofilefs_mkdir(struct super_block *sb, |
| 211 | struct dentry *root, char const *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 213 | struct dentry *dentry; |
| 214 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
| 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; |
| 223 | } |
| 224 | inode->i_op = &simple_dir_inode_operations; |
| 225 | inode->i_fop = &simple_dir_operations; |
| 226 | d_add(dentry, inode); |
| 227 | return dentry; |
| 228 | } |
| 229 | |
| 230 | |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 231 | 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] | 232 | { |
Robert Richter | 25ad2913 | 2008-09-05 17:12:36 +0200 | [diff] [blame] | 233 | struct inode *root_inode; |
| 234 | struct dentry *root_dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | |
| 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; |
| 241 | |
| 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; |
| 251 | } |
| 252 | |
| 253 | sb->s_root = root_dentry; |
| 254 | |
| 255 | oprofile_create_files(sb, root_dentry); |
| 256 | |
| 257 | // FIXME: verify kill_litter_super removes our dentries |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 262 | static struct dentry *oprofilefs_mount(struct file_system_type *fs_type, |
| 263 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 265 | return mount_single(fs_type, flags, data, oprofilefs_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | } |
| 267 | |
| 268 | |
| 269 | static struct file_system_type oprofilefs_type = { |
| 270 | .owner = THIS_MODULE, |
| 271 | .name = "oprofilefs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 272 | .mount = oprofilefs_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | .kill_sb = kill_litter_super, |
| 274 | }; |
| 275 | |
| 276 | |
| 277 | int __init oprofilefs_register(void) |
| 278 | { |
| 279 | return register_filesystem(&oprofilefs_type); |
| 280 | } |
| 281 | |
| 282 | |
| 283 | void __exit oprofilefs_unregister(void) |
| 284 | { |
| 285 | unregister_filesystem(&oprofilefs_type); |
| 286 | } |