2 * dir.c - Operations for sysfs directories.
8 #include <linux/mount.h>
9 #include <linux/module.h>
10 #include <linux/kobject.h>
13 DECLARE_RWSEM(sysfs_rename_sem);
15 static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
17 struct sysfs_dirent * sd = dentry->d_fsdata;
20 BUG_ON(sd->s_dentry != dentry);
27 static struct dentry_operations sysfs_dentry_ops = {
28 .d_iput = sysfs_d_iput,
32 * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
34 static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
37 struct sysfs_dirent * sd;
39 sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
43 memset(sd, 0, sizeof(*sd));
44 atomic_set(&sd->s_count, 1);
45 INIT_LIST_HEAD(&sd->s_children);
46 list_add(&sd->s_sibling, &parent_sd->s_children);
47 sd->s_element = element;
52 int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
53 void * element, umode_t mode, int type)
55 struct sysfs_dirent * sd;
57 sd = sysfs_new_dirent(parent_sd, element);
63 sd->s_dentry = dentry;
65 dentry->d_fsdata = sysfs_get(sd);
66 dentry->d_op = &sysfs_dentry_ops;
72 static int init_dir(struct inode * inode)
74 inode->i_op = &sysfs_dir_inode_operations;
75 inode->i_fop = &sysfs_dir_operations;
77 /* directory inodes start off with i_nlink == 2 (for "." entry) */
82 static int init_file(struct inode * inode)
84 inode->i_size = PAGE_SIZE;
85 inode->i_fop = &sysfs_file_operations;
89 static int init_symlink(struct inode * inode)
91 inode->i_op = &sysfs_symlink_inode_operations;
95 static int create_dir(struct kobject * k, struct dentry * p,
96 const char * n, struct dentry ** d)
99 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
101 down(&p->d_inode->i_sem);
102 *d = sysfs_get_dentry(p,n);
104 error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
106 error = sysfs_create(*d, mode, init_dir);
108 p->d_inode->i_nlink++;
109 (*d)->d_op = &sysfs_dentry_ops;
113 if (error && (error != -EEXIST)) {
114 sysfs_put((*d)->d_fsdata);
120 up(&p->d_inode->i_sem);
125 int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
127 return create_dir(k,k->dentry,n,d);
131 * sysfs_create_dir - create a directory for an object.
132 * @parent: parent parent object.
133 * @kobj: object we're creating directory for.
136 int sysfs_create_dir(struct kobject * kobj)
138 struct dentry * dentry = NULL;
139 struct dentry * parent;
145 parent = kobj->parent->dentry;
146 else if (sysfs_mount && sysfs_mount->mnt_sb)
147 parent = sysfs_mount->mnt_sb->s_root;
151 error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
153 kobj->dentry = dentry;
157 /* attaches attribute's sysfs_dirent to the dentry corresponding to the
160 static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
162 struct attribute * attr = NULL;
163 struct bin_attribute * bin_attr = NULL;
164 int (* init) (struct inode *) = NULL;
167 if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
168 bin_attr = sd->s_element;
169 attr = &bin_attr->attr;
171 attr = sd->s_element;
175 dentry->d_fsdata = sysfs_get(sd);
176 sd->s_dentry = dentry;
177 error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
184 dentry->d_inode->i_size = bin_attr->size;
185 dentry->d_inode->i_fop = &bin_fops;
187 dentry->d_op = &sysfs_dentry_ops;
193 static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
197 dentry->d_fsdata = sysfs_get(sd);
198 sd->s_dentry = dentry;
199 err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
201 dentry->d_op = &sysfs_dentry_ops;
209 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
210 struct nameidata *nd)
212 struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
213 struct sysfs_dirent * sd;
216 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
217 if (sd->s_type & SYSFS_NOT_PINNED) {
218 const unsigned char * name = sysfs_get_name(sd);
220 if (strcmp(name, dentry->d_name.name))
223 if (sd->s_type & SYSFS_KOBJ_LINK)
224 err = sysfs_attach_link(sd, dentry);
226 err = sysfs_attach_attr(sd, dentry);
234 struct inode_operations sysfs_dir_inode_operations = {
235 .lookup = sysfs_lookup,
238 static void remove_dir(struct dentry * d)
240 struct dentry * parent = dget(d->d_parent);
241 struct sysfs_dirent * sd;
243 down(&parent->d_inode->i_sem);
246 list_del_init(&sd->s_sibling);
249 simple_rmdir(parent->d_inode,d);
251 pr_debug(" o %s removing done (%d)\n",d->d_name.name,
252 atomic_read(&d->d_count));
254 up(&parent->d_inode->i_sem);
258 void sysfs_remove_subdir(struct dentry * d)
265 * sysfs_remove_dir - remove an object's directory.
268 * The only thing special about this is that we remove any files in
269 * the directory before we remove the directory, and we've inlined
270 * what used to be sysfs_rmdir() below, instead of calling separately.
273 void sysfs_remove_dir(struct kobject * kobj)
275 struct dentry * dentry = dget(kobj->dentry);
276 struct sysfs_dirent * parent_sd;
277 struct sysfs_dirent * sd, * tmp;
282 pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
283 down(&dentry->d_inode->i_sem);
284 parent_sd = dentry->d_fsdata;
285 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
286 if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
288 list_del_init(&sd->s_sibling);
289 sysfs_drop_dentry(sd, dentry);
292 up(&dentry->d_inode->i_sem);
296 * Drop reference from dget() on entrance.
301 int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
304 struct dentry * new_dentry, * parent;
306 if (!strcmp(kobject_name(kobj), new_name))
312 down_write(&sysfs_rename_sem);
313 parent = kobj->parent->dentry;
315 down(&parent->d_inode->i_sem);
317 new_dentry = sysfs_get_dentry(parent, new_name);
318 if (!IS_ERR(new_dentry)) {
319 if (!new_dentry->d_inode) {
320 error = kobject_set_name(kobj, "%s", new_name);
322 d_add(new_dentry, NULL);
323 d_move(kobj->dentry, new_dentry);
331 up(&parent->d_inode->i_sem);
332 up_write(&sysfs_rename_sem);
337 static int sysfs_dir_open(struct inode *inode, struct file *file)
339 struct dentry * dentry = file->f_dentry;
340 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
342 down(&dentry->d_inode->i_sem);
343 file->private_data = sysfs_new_dirent(parent_sd, NULL);
344 up(&dentry->d_inode->i_sem);
346 return file->private_data ? 0 : -ENOMEM;
350 static int sysfs_dir_close(struct inode *inode, struct file *file)
352 struct dentry * dentry = file->f_dentry;
353 struct sysfs_dirent * cursor = file->private_data;
355 down(&dentry->d_inode->i_sem);
356 list_del_init(&cursor->s_sibling);
357 up(&dentry->d_inode->i_sem);
359 release_sysfs_dirent(cursor);
364 /* Relationship between s_mode and the DT_xxx types */
365 static inline unsigned char dt_type(struct sysfs_dirent *sd)
367 return (sd->s_mode >> 12) & 15;
370 static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
372 struct dentry *dentry = filp->f_dentry;
373 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
374 struct sysfs_dirent *cursor = filp->private_data;
375 struct list_head *p, *q = &cursor->s_sibling;
381 ino = dentry->d_inode->i_ino;
382 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
388 ino = parent_ino(dentry);
389 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
395 if (filp->f_pos == 2) {
397 list_add(q, &parent_sd->s_children);
399 for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
400 struct sysfs_dirent *next;
404 next = list_entry(p, struct sysfs_dirent,
406 if (!next->s_element)
409 name = sysfs_get_name(next);
412 ino = next->s_dentry->d_inode->i_ino;
414 ino = iunique(sysfs_sb, 2);
416 if (filldir(dirent, name, len, filp->f_pos, ino,
429 static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
431 struct dentry * dentry = file->f_dentry;
433 down(&dentry->d_inode->i_sem);
436 offset += file->f_pos;
441 up(&file->f_dentry->d_inode->i_sem);
444 if (offset != file->f_pos) {
445 file->f_pos = offset;
446 if (file->f_pos >= 2) {
447 struct sysfs_dirent *sd = dentry->d_fsdata;
448 struct sysfs_dirent *cursor = file->private_data;
450 loff_t n = file->f_pos - 2;
452 list_del(&cursor->s_sibling);
453 p = sd->s_children.next;
454 while (n && p != &sd->s_children) {
455 struct sysfs_dirent *next;
456 next = list_entry(p, struct sysfs_dirent,
462 list_add_tail(&cursor->s_sibling, p);
465 up(&dentry->d_inode->i_sem);
469 struct file_operations sysfs_dir_operations = {
470 .open = sysfs_dir_open,
471 .release = sysfs_dir_close,
472 .llseek = sysfs_dir_lseek,
473 .read = generic_read_dir,
474 .readdir = sysfs_readdir,
477 EXPORT_SYMBOL_GPL(sysfs_create_dir);
478 EXPORT_SYMBOL_GPL(sysfs_remove_dir);
479 EXPORT_SYMBOL_GPL(sysfs_rename_dir);