Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * dir.c - Operations for sysfs directories. |
| 3 | */ |
| 4 | |
| 5 | #undef DEBUG |
| 6 | |
| 7 | #include <linux/fs.h> |
| 8 | #include <linux/mount.h> |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/kobject.h> |
Christoph Hellwig | 5f45f1a | 2005-06-23 00:09:12 -0700 | [diff] [blame] | 11 | #include <linux/namei.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include "sysfs.h" |
| 13 | |
| 14 | DECLARE_RWSEM(sysfs_rename_sem); |
| 15 | |
| 16 | static void sysfs_d_iput(struct dentry * dentry, struct inode * inode) |
| 17 | { |
| 18 | struct sysfs_dirent * sd = dentry->d_fsdata; |
| 19 | |
| 20 | if (sd) { |
| 21 | BUG_ON(sd->s_dentry != dentry); |
| 22 | sd->s_dentry = NULL; |
| 23 | sysfs_put(sd); |
| 24 | } |
| 25 | iput(inode); |
| 26 | } |
| 27 | |
| 28 | static struct dentry_operations sysfs_dentry_ops = { |
| 29 | .d_iput = sysfs_d_iput, |
| 30 | }; |
| 31 | |
| 32 | /* |
| 33 | * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent |
| 34 | */ |
| 35 | static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd, |
| 36 | void * element) |
| 37 | { |
| 38 | struct sysfs_dirent * sd; |
| 39 | |
| 40 | sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL); |
| 41 | if (!sd) |
| 42 | return NULL; |
| 43 | |
| 44 | memset(sd, 0, sizeof(*sd)); |
| 45 | atomic_set(&sd->s_count, 1); |
| 46 | INIT_LIST_HEAD(&sd->s_children); |
| 47 | list_add(&sd->s_sibling, &parent_sd->s_children); |
| 48 | sd->s_element = element; |
| 49 | |
| 50 | return sd; |
| 51 | } |
| 52 | |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 53 | /** |
| 54 | * |
| 55 | * Return -EEXIST if there is already a sysfs element with the same name for |
| 56 | * the same parent. |
| 57 | * |
| 58 | * called with parent inode's i_mutex held |
| 59 | */ |
| 60 | int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, |
| 61 | const unsigned char *new) |
| 62 | { |
| 63 | struct sysfs_dirent * sd; |
| 64 | |
| 65 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { |
| 66 | if (sd->s_element) { |
| 67 | const unsigned char *existing = sysfs_get_name(sd); |
| 68 | if (strcmp(existing, new)) |
| 69 | continue; |
| 70 | else |
| 71 | return -EEXIST; |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, |
| 80 | void * element, umode_t mode, int type) |
| 81 | { |
| 82 | struct sysfs_dirent * sd; |
| 83 | |
| 84 | sd = sysfs_new_dirent(parent_sd, element); |
| 85 | if (!sd) |
| 86 | return -ENOMEM; |
| 87 | |
| 88 | sd->s_mode = mode; |
| 89 | sd->s_type = type; |
| 90 | sd->s_dentry = dentry; |
| 91 | if (dentry) { |
| 92 | dentry->d_fsdata = sysfs_get(sd); |
| 93 | dentry->d_op = &sysfs_dentry_ops; |
| 94 | } |
| 95 | |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | static int init_dir(struct inode * inode) |
| 100 | { |
| 101 | inode->i_op = &sysfs_dir_inode_operations; |
| 102 | inode->i_fop = &sysfs_dir_operations; |
| 103 | |
| 104 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 105 | inode->i_nlink++; |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int init_file(struct inode * inode) |
| 110 | { |
| 111 | inode->i_size = PAGE_SIZE; |
| 112 | inode->i_fop = &sysfs_file_operations; |
| 113 | return 0; |
| 114 | } |
| 115 | |
| 116 | static int init_symlink(struct inode * inode) |
| 117 | { |
| 118 | inode->i_op = &sysfs_symlink_inode_operations; |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static int create_dir(struct kobject * k, struct dentry * p, |
| 123 | const char * n, struct dentry ** d) |
| 124 | { |
| 125 | int error; |
| 126 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
| 127 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 128 | mutex_lock(&p->d_inode->i_mutex); |
Christoph Hellwig | 5f45f1a | 2005-06-23 00:09:12 -0700 | [diff] [blame] | 129 | *d = lookup_one_len(n, p, strlen(n)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | if (!IS_ERR(*d)) { |
Maneesh Soni | c516865 | 2006-03-09 19:40:14 +0530 | [diff] [blame] | 131 | if (sysfs_dirent_exist(p->d_fsdata, n)) |
| 132 | error = -EEXIST; |
| 133 | else |
| 134 | error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, |
| 135 | SYSFS_DIR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | if (!error) { |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 137 | error = sysfs_create(*d, mode, init_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | if (!error) { |
| 139 | p->d_inode->i_nlink++; |
| 140 | (*d)->d_op = &sysfs_dentry_ops; |
| 141 | d_rehash(*d); |
| 142 | } |
| 143 | } |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 144 | if (error && (error != -EEXIST)) { |
Steven Rostedt | e80a5de | 2005-11-23 09:15:44 -0500 | [diff] [blame] | 145 | struct sysfs_dirent *sd = (*d)->d_fsdata; |
| 146 | if (sd) { |
| 147 | list_del_init(&sd->s_sibling); |
| 148 | sysfs_put(sd); |
| 149 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | d_drop(*d); |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 151 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | dput(*d); |
| 153 | } else |
| 154 | error = PTR_ERR(*d); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 155 | mutex_unlock(&p->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | return error; |
| 157 | } |
| 158 | |
| 159 | |
| 160 | int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) |
| 161 | { |
| 162 | return create_dir(k,k->dentry,n,d); |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * sysfs_create_dir - create a directory for an object. |
| 167 | * @parent: parent parent object. |
| 168 | * @kobj: object we're creating directory for. |
| 169 | */ |
| 170 | |
| 171 | int sysfs_create_dir(struct kobject * kobj) |
| 172 | { |
| 173 | struct dentry * dentry = NULL; |
| 174 | struct dentry * parent; |
| 175 | int error = 0; |
| 176 | |
| 177 | BUG_ON(!kobj); |
| 178 | |
| 179 | if (kobj->parent) |
| 180 | parent = kobj->parent->dentry; |
| 181 | else if (sysfs_mount && sysfs_mount->mnt_sb) |
| 182 | parent = sysfs_mount->mnt_sb->s_root; |
| 183 | else |
| 184 | return -EFAULT; |
| 185 | |
| 186 | error = create_dir(kobj,parent,kobject_name(kobj),&dentry); |
| 187 | if (!error) |
| 188 | kobj->dentry = dentry; |
| 189 | return error; |
| 190 | } |
| 191 | |
| 192 | /* attaches attribute's sysfs_dirent to the dentry corresponding to the |
| 193 | * attribute file |
| 194 | */ |
| 195 | static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry) |
| 196 | { |
| 197 | struct attribute * attr = NULL; |
| 198 | struct bin_attribute * bin_attr = NULL; |
| 199 | int (* init) (struct inode *) = NULL; |
| 200 | int error = 0; |
| 201 | |
| 202 | if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) { |
| 203 | bin_attr = sd->s_element; |
| 204 | attr = &bin_attr->attr; |
| 205 | } else { |
| 206 | attr = sd->s_element; |
| 207 | init = init_file; |
| 208 | } |
| 209 | |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 210 | dentry->d_fsdata = sysfs_get(sd); |
| 211 | sd->s_dentry = dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init); |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 213 | if (error) { |
| 214 | sysfs_put(sd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | return error; |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 216 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | |
| 218 | if (bin_attr) { |
| 219 | dentry->d_inode->i_size = bin_attr->size; |
| 220 | dentry->d_inode->i_fop = &bin_fops; |
| 221 | } |
| 222 | dentry->d_op = &sysfs_dentry_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | d_rehash(dentry); |
| 224 | |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry) |
| 229 | { |
| 230 | int err = 0; |
| 231 | |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 232 | dentry->d_fsdata = sysfs_get(sd); |
| 233 | sd->s_dentry = dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink); |
| 235 | if (!err) { |
| 236 | dentry->d_op = &sysfs_dentry_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | d_rehash(dentry); |
Maneesh Soni | 6fa5c82 | 2005-05-31 10:38:12 +0530 | [diff] [blame] | 238 | } else |
| 239 | sysfs_put(sd); |
| 240 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | return err; |
| 242 | } |
| 243 | |
| 244 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
| 245 | struct nameidata *nd) |
| 246 | { |
| 247 | struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata; |
| 248 | struct sysfs_dirent * sd; |
| 249 | int err = 0; |
| 250 | |
| 251 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { |
| 252 | if (sd->s_type & SYSFS_NOT_PINNED) { |
| 253 | const unsigned char * name = sysfs_get_name(sd); |
| 254 | |
| 255 | if (strcmp(name, dentry->d_name.name)) |
| 256 | continue; |
| 257 | |
| 258 | if (sd->s_type & SYSFS_KOBJ_LINK) |
| 259 | err = sysfs_attach_link(sd, dentry); |
| 260 | else |
| 261 | err = sysfs_attach_attr(sd, dentry); |
| 262 | break; |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | return ERR_PTR(err); |
| 267 | } |
| 268 | |
| 269 | struct inode_operations sysfs_dir_inode_operations = { |
| 270 | .lookup = sysfs_lookup, |
Maneesh Soni | 988d186 | 2005-05-31 10:39:14 +0530 | [diff] [blame] | 271 | .setattr = sysfs_setattr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | }; |
| 273 | |
| 274 | static void remove_dir(struct dentry * d) |
| 275 | { |
| 276 | struct dentry * parent = dget(d->d_parent); |
| 277 | struct sysfs_dirent * sd; |
| 278 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 279 | mutex_lock(&parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | d_delete(d); |
| 281 | sd = d->d_fsdata; |
| 282 | list_del_init(&sd->s_sibling); |
| 283 | sysfs_put(sd); |
| 284 | if (d->d_inode) |
| 285 | simple_rmdir(parent->d_inode,d); |
| 286 | |
| 287 | pr_debug(" o %s removing done (%d)\n",d->d_name.name, |
| 288 | atomic_read(&d->d_count)); |
| 289 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 290 | mutex_unlock(&parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | dput(parent); |
| 292 | } |
| 293 | |
| 294 | void sysfs_remove_subdir(struct dentry * d) |
| 295 | { |
| 296 | remove_dir(d); |
| 297 | } |
| 298 | |
| 299 | |
| 300 | /** |
| 301 | * sysfs_remove_dir - remove an object's directory. |
| 302 | * @kobj: object. |
| 303 | * |
| 304 | * The only thing special about this is that we remove any files in |
| 305 | * the directory before we remove the directory, and we've inlined |
| 306 | * what used to be sysfs_rmdir() below, instead of calling separately. |
| 307 | */ |
| 308 | |
| 309 | void sysfs_remove_dir(struct kobject * kobj) |
| 310 | { |
| 311 | struct dentry * dentry = dget(kobj->dentry); |
| 312 | struct sysfs_dirent * parent_sd; |
| 313 | struct sysfs_dirent * sd, * tmp; |
| 314 | |
| 315 | if (!dentry) |
| 316 | return; |
| 317 | |
| 318 | pr_debug("sysfs %s: removing dir\n",dentry->d_name.name); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 319 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | parent_sd = dentry->d_fsdata; |
| 321 | list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { |
| 322 | if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED)) |
| 323 | continue; |
| 324 | list_del_init(&sd->s_sibling); |
| 325 | sysfs_drop_dentry(sd, dentry); |
| 326 | sysfs_put(sd); |
| 327 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 328 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
| 330 | remove_dir(dentry); |
| 331 | /** |
| 332 | * Drop reference from dget() on entrance. |
| 333 | */ |
| 334 | dput(dentry); |
Greg Kroah-Hartman | 641e6f3 | 2006-03-16 15:44:26 -0800 | [diff] [blame] | 335 | kobj->dentry = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | } |
| 337 | |
| 338 | int sysfs_rename_dir(struct kobject * kobj, const char *new_name) |
| 339 | { |
| 340 | int error = 0; |
| 341 | struct dentry * new_dentry, * parent; |
| 342 | |
| 343 | if (!strcmp(kobject_name(kobj), new_name)) |
| 344 | return -EINVAL; |
| 345 | |
| 346 | if (!kobj->parent) |
| 347 | return -EINVAL; |
| 348 | |
| 349 | down_write(&sysfs_rename_sem); |
| 350 | parent = kobj->parent->dentry; |
| 351 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 352 | mutex_lock(&parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | |
Christoph Hellwig | 5f45f1a | 2005-06-23 00:09:12 -0700 | [diff] [blame] | 354 | new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | if (!IS_ERR(new_dentry)) { |
| 356 | if (!new_dentry->d_inode) { |
| 357 | error = kobject_set_name(kobj, "%s", new_name); |
| 358 | if (!error) { |
| 359 | d_add(new_dentry, NULL); |
| 360 | d_move(kobj->dentry, new_dentry); |
| 361 | } |
| 362 | else |
| 363 | d_drop(new_dentry); |
| 364 | } else |
| 365 | error = -EEXIST; |
| 366 | dput(new_dentry); |
| 367 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 368 | mutex_unlock(&parent->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | up_write(&sysfs_rename_sem); |
| 370 | |
| 371 | return error; |
| 372 | } |
| 373 | |
| 374 | static int sysfs_dir_open(struct inode *inode, struct file *file) |
| 375 | { |
| 376 | struct dentry * dentry = file->f_dentry; |
| 377 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
| 378 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 379 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | file->private_data = sysfs_new_dirent(parent_sd, NULL); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 381 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | |
| 383 | return file->private_data ? 0 : -ENOMEM; |
| 384 | |
| 385 | } |
| 386 | |
| 387 | static int sysfs_dir_close(struct inode *inode, struct file *file) |
| 388 | { |
| 389 | struct dentry * dentry = file->f_dentry; |
| 390 | struct sysfs_dirent * cursor = file->private_data; |
| 391 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 392 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | list_del_init(&cursor->s_sibling); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 394 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | |
| 396 | release_sysfs_dirent(cursor); |
| 397 | |
| 398 | return 0; |
| 399 | } |
| 400 | |
| 401 | /* Relationship between s_mode and the DT_xxx types */ |
| 402 | static inline unsigned char dt_type(struct sysfs_dirent *sd) |
| 403 | { |
| 404 | return (sd->s_mode >> 12) & 15; |
| 405 | } |
| 406 | |
| 407 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) |
| 408 | { |
| 409 | struct dentry *dentry = filp->f_dentry; |
| 410 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
| 411 | struct sysfs_dirent *cursor = filp->private_data; |
| 412 | struct list_head *p, *q = &cursor->s_sibling; |
| 413 | ino_t ino; |
| 414 | int i = filp->f_pos; |
| 415 | |
| 416 | switch (i) { |
| 417 | case 0: |
| 418 | ino = dentry->d_inode->i_ino; |
| 419 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) |
| 420 | break; |
| 421 | filp->f_pos++; |
| 422 | i++; |
| 423 | /* fallthrough */ |
| 424 | case 1: |
| 425 | ino = parent_ino(dentry); |
| 426 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) |
| 427 | break; |
| 428 | filp->f_pos++; |
| 429 | i++; |
| 430 | /* fallthrough */ |
| 431 | default: |
| 432 | if (filp->f_pos == 2) { |
| 433 | list_del(q); |
| 434 | list_add(q, &parent_sd->s_children); |
| 435 | } |
| 436 | for (p=q->next; p!= &parent_sd->s_children; p=p->next) { |
| 437 | struct sysfs_dirent *next; |
| 438 | const char * name; |
| 439 | int len; |
| 440 | |
| 441 | next = list_entry(p, struct sysfs_dirent, |
| 442 | s_sibling); |
| 443 | if (!next->s_element) |
| 444 | continue; |
| 445 | |
| 446 | name = sysfs_get_name(next); |
| 447 | len = strlen(name); |
| 448 | if (next->s_dentry) |
| 449 | ino = next->s_dentry->d_inode->i_ino; |
| 450 | else |
| 451 | ino = iunique(sysfs_sb, 2); |
| 452 | |
| 453 | if (filldir(dirent, name, len, filp->f_pos, ino, |
| 454 | dt_type(next)) < 0) |
| 455 | return 0; |
| 456 | |
| 457 | list_del(q); |
| 458 | list_add(q, p); |
| 459 | p = q; |
| 460 | filp->f_pos++; |
| 461 | } |
| 462 | } |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) |
| 467 | { |
| 468 | struct dentry * dentry = file->f_dentry; |
| 469 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 470 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | switch (origin) { |
| 472 | case 1: |
| 473 | offset += file->f_pos; |
| 474 | case 0: |
| 475 | if (offset >= 0) |
| 476 | break; |
| 477 | default: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 478 | mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | return -EINVAL; |
| 480 | } |
| 481 | if (offset != file->f_pos) { |
| 482 | file->f_pos = offset; |
| 483 | if (file->f_pos >= 2) { |
| 484 | struct sysfs_dirent *sd = dentry->d_fsdata; |
| 485 | struct sysfs_dirent *cursor = file->private_data; |
| 486 | struct list_head *p; |
| 487 | loff_t n = file->f_pos - 2; |
| 488 | |
| 489 | list_del(&cursor->s_sibling); |
| 490 | p = sd->s_children.next; |
| 491 | while (n && p != &sd->s_children) { |
| 492 | struct sysfs_dirent *next; |
| 493 | next = list_entry(p, struct sysfs_dirent, |
| 494 | s_sibling); |
| 495 | if (next->s_element) |
| 496 | n--; |
| 497 | p = p->next; |
| 498 | } |
| 499 | list_add_tail(&cursor->s_sibling, p); |
| 500 | } |
| 501 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 502 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | return offset; |
| 504 | } |
| 505 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 506 | const struct file_operations sysfs_dir_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | .open = sysfs_dir_open, |
| 508 | .release = sysfs_dir_close, |
| 509 | .llseek = sysfs_dir_lseek, |
| 510 | .read = generic_read_dir, |
| 511 | .readdir = sysfs_readdir, |
| 512 | }; |