2 * dir.c - Operations for sysfs directories.
8 #include <linux/mount.h>
9 #include <linux/module.h>
10 #include <linux/kobject.h>
11 #include <linux/namei.h>
14 DECLARE_RWSEM(sysfs_rename_sem);
16 static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
18 struct sysfs_dirent * sd = dentry->d_fsdata;
21 BUG_ON(sd->s_dentry != dentry);
28 static struct dentry_operations sysfs_dentry_ops = {
29 .d_iput = sysfs_d_iput,
33 * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
35 static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
38 struct sysfs_dirent * sd;
40 sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
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;
53 int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
54 void * element, umode_t mode, int type)
56 struct sysfs_dirent * sd;
58 sd = sysfs_new_dirent(parent_sd, element);
64 sd->s_dentry = dentry;
66 dentry->d_fsdata = sysfs_get(sd);
67 dentry->d_op = &sysfs_dentry_ops;
73 static int init_dir(struct inode * inode)
75 inode->i_op = &sysfs_dir_inode_operations;
76 inode->i_fop = &sysfs_dir_operations;
78 /* directory inodes start off with i_nlink == 2 (for "." entry) */
83 static int init_file(struct inode * inode)
85 inode->i_size = PAGE_SIZE;
86 inode->i_fop = &sysfs_file_operations;
90 static int init_symlink(struct inode * inode)
92 inode->i_op = &sysfs_symlink_inode_operations;
96 static int create_dir(struct kobject * k, struct dentry * p,
97 const char * n, struct dentry ** d)
100 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
102 mutex_lock(&p->d_inode->i_mutex);
103 *d = lookup_one_len(n, p, strlen(n));
105 error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
107 error = sysfs_create(*d, mode, init_dir);
109 p->d_inode->i_nlink++;
110 (*d)->d_op = &sysfs_dentry_ops;
114 if (error && (error != -EEXIST)) {
115 struct sysfs_dirent *sd = (*d)->d_fsdata;
117 list_del_init(&sd->s_sibling);
125 mutex_unlock(&p->d_inode->i_mutex);
130 int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
132 return create_dir(k,k->dentry,n,d);
136 * sysfs_create_dir - create a directory for an object.
137 * @parent: parent parent object.
138 * @kobj: object we're creating directory for.
141 int sysfs_create_dir(struct kobject * kobj)
143 struct dentry * dentry = NULL;
144 struct dentry * parent;
150 parent = kobj->parent->dentry;
151 else if (sysfs_mount && sysfs_mount->mnt_sb)
152 parent = sysfs_mount->mnt_sb->s_root;
156 error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
158 kobj->dentry = dentry;
162 /* attaches attribute's sysfs_dirent to the dentry corresponding to the
165 static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
167 struct attribute * attr = NULL;
168 struct bin_attribute * bin_attr = NULL;
169 int (* init) (struct inode *) = NULL;
172 if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
173 bin_attr = sd->s_element;
174 attr = &bin_attr->attr;
176 attr = sd->s_element;
180 dentry->d_fsdata = sysfs_get(sd);
181 sd->s_dentry = dentry;
182 error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
189 dentry->d_inode->i_size = bin_attr->size;
190 dentry->d_inode->i_fop = &bin_fops;
192 dentry->d_op = &sysfs_dentry_ops;
198 static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
202 dentry->d_fsdata = sysfs_get(sd);
203 sd->s_dentry = dentry;
204 err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
206 dentry->d_op = &sysfs_dentry_ops;
214 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
215 struct nameidata *nd)
217 struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
218 struct sysfs_dirent * sd;
221 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
222 if (sd->s_type & SYSFS_NOT_PINNED) {
223 const unsigned char * name = sysfs_get_name(sd);
225 if (strcmp(name, dentry->d_name.name))
228 if (sd->s_type & SYSFS_KOBJ_LINK)
229 err = sysfs_attach_link(sd, dentry);
231 err = sysfs_attach_attr(sd, dentry);
239 struct inode_operations sysfs_dir_inode_operations = {
240 .lookup = sysfs_lookup,
241 .setattr = sysfs_setattr,
244 static void remove_dir(struct dentry * d)
246 struct dentry * parent = dget(d->d_parent);
247 struct sysfs_dirent * sd;
249 mutex_lock(&parent->d_inode->i_mutex);
252 list_del_init(&sd->s_sibling);
255 simple_rmdir(parent->d_inode,d);
257 pr_debug(" o %s removing done (%d)\n",d->d_name.name,
258 atomic_read(&d->d_count));
260 mutex_unlock(&parent->d_inode->i_mutex);
264 void sysfs_remove_subdir(struct dentry * d)
271 * sysfs_remove_dir - remove an object's directory.
274 * The only thing special about this is that we remove any files in
275 * the directory before we remove the directory, and we've inlined
276 * what used to be sysfs_rmdir() below, instead of calling separately.
279 void sysfs_remove_dir(struct kobject * kobj)
281 struct dentry * dentry = dget(kobj->dentry);
282 struct sysfs_dirent * parent_sd;
283 struct sysfs_dirent * sd, * tmp;
288 pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
289 mutex_lock(&dentry->d_inode->i_mutex);
290 parent_sd = dentry->d_fsdata;
291 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
292 if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
294 list_del_init(&sd->s_sibling);
295 sysfs_drop_dentry(sd, dentry);
298 mutex_unlock(&dentry->d_inode->i_mutex);
302 * Drop reference from dget() on entrance.
307 int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
310 struct dentry * new_dentry, * parent;
312 if (!strcmp(kobject_name(kobj), new_name))
318 down_write(&sysfs_rename_sem);
319 parent = kobj->parent->dentry;
321 mutex_lock(&parent->d_inode->i_mutex);
323 new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
324 if (!IS_ERR(new_dentry)) {
325 if (!new_dentry->d_inode) {
326 error = kobject_set_name(kobj, "%s", new_name);
328 d_add(new_dentry, NULL);
329 d_move(kobj->dentry, new_dentry);
337 mutex_unlock(&parent->d_inode->i_mutex);
338 up_write(&sysfs_rename_sem);
343 static int sysfs_dir_open(struct inode *inode, struct file *file)
345 struct dentry * dentry = file->f_dentry;
346 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
348 mutex_lock(&dentry->d_inode->i_mutex);
349 file->private_data = sysfs_new_dirent(parent_sd, NULL);
350 mutex_unlock(&dentry->d_inode->i_mutex);
352 return file->private_data ? 0 : -ENOMEM;
356 static int sysfs_dir_close(struct inode *inode, struct file *file)
358 struct dentry * dentry = file->f_dentry;
359 struct sysfs_dirent * cursor = file->private_data;
361 mutex_lock(&dentry->d_inode->i_mutex);
362 list_del_init(&cursor->s_sibling);
363 mutex_unlock(&dentry->d_inode->i_mutex);
365 release_sysfs_dirent(cursor);
370 /* Relationship between s_mode and the DT_xxx types */
371 static inline unsigned char dt_type(struct sysfs_dirent *sd)
373 return (sd->s_mode >> 12) & 15;
376 static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
378 struct dentry *dentry = filp->f_dentry;
379 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
380 struct sysfs_dirent *cursor = filp->private_data;
381 struct list_head *p, *q = &cursor->s_sibling;
387 ino = dentry->d_inode->i_ino;
388 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
394 ino = parent_ino(dentry);
395 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
401 if (filp->f_pos == 2) {
403 list_add(q, &parent_sd->s_children);
405 for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
406 struct sysfs_dirent *next;
410 next = list_entry(p, struct sysfs_dirent,
412 if (!next->s_element)
415 name = sysfs_get_name(next);
418 ino = next->s_dentry->d_inode->i_ino;
420 ino = iunique(sysfs_sb, 2);
422 if (filldir(dirent, name, len, filp->f_pos, ino,
435 static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
437 struct dentry * dentry = file->f_dentry;
439 mutex_lock(&dentry->d_inode->i_mutex);
442 offset += file->f_pos;
447 mutex_unlock(&file->f_dentry->d_inode->i_mutex);
450 if (offset != file->f_pos) {
451 file->f_pos = offset;
452 if (file->f_pos >= 2) {
453 struct sysfs_dirent *sd = dentry->d_fsdata;
454 struct sysfs_dirent *cursor = file->private_data;
456 loff_t n = file->f_pos - 2;
458 list_del(&cursor->s_sibling);
459 p = sd->s_children.next;
460 while (n && p != &sd->s_children) {
461 struct sysfs_dirent *next;
462 next = list_entry(p, struct sysfs_dirent,
468 list_add_tail(&cursor->s_sibling, p);
471 mutex_unlock(&dentry->d_inode->i_mutex);
475 struct file_operations sysfs_dir_operations = {
476 .open = sysfs_dir_open,
477 .release = sysfs_dir_close,
478 .llseek = sysfs_dir_lseek,
479 .read = generic_read_dir,
480 .readdir = sysfs_readdir,
483 EXPORT_SYMBOL_GPL(sysfs_create_dir);
484 EXPORT_SYMBOL_GPL(sysfs_remove_dir);
485 EXPORT_SYMBOL_GPL(sysfs_rename_dir);