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 down(&p->d_inode->i_sem);
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 sysfs_put((*d)->d_fsdata);
121 up(&p->d_inode->i_sem);
126 int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
128 return create_dir(k,k->dentry,n,d);
132 * sysfs_create_dir - create a directory for an object.
133 * @parent: parent parent object.
134 * @kobj: object we're creating directory for.
137 int sysfs_create_dir(struct kobject * kobj)
139 struct dentry * dentry = NULL;
140 struct dentry * parent;
146 parent = kobj->parent->dentry;
147 else if (sysfs_mount && sysfs_mount->mnt_sb)
148 parent = sysfs_mount->mnt_sb->s_root;
152 error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
154 kobj->dentry = dentry;
158 /* attaches attribute's sysfs_dirent to the dentry corresponding to the
161 static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
163 struct attribute * attr = NULL;
164 struct bin_attribute * bin_attr = NULL;
165 int (* init) (struct inode *) = NULL;
168 if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
169 bin_attr = sd->s_element;
170 attr = &bin_attr->attr;
172 attr = sd->s_element;
176 dentry->d_fsdata = sysfs_get(sd);
177 sd->s_dentry = dentry;
178 error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
185 dentry->d_inode->i_size = bin_attr->size;
186 dentry->d_inode->i_fop = &bin_fops;
188 dentry->d_op = &sysfs_dentry_ops;
194 static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
198 dentry->d_fsdata = sysfs_get(sd);
199 sd->s_dentry = dentry;
200 err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
202 dentry->d_op = &sysfs_dentry_ops;
210 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
211 struct nameidata *nd)
213 struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
214 struct sysfs_dirent * sd;
217 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
218 if (sd->s_type & SYSFS_NOT_PINNED) {
219 const unsigned char * name = sysfs_get_name(sd);
221 if (strcmp(name, dentry->d_name.name))
224 if (sd->s_type & SYSFS_KOBJ_LINK)
225 err = sysfs_attach_link(sd, dentry);
227 err = sysfs_attach_attr(sd, dentry);
235 struct inode_operations sysfs_dir_inode_operations = {
236 .lookup = sysfs_lookup,
237 .setattr = sysfs_setattr,
240 static void remove_dir(struct dentry * d)
242 struct dentry * parent = dget(d->d_parent);
243 struct sysfs_dirent * sd;
245 down(&parent->d_inode->i_sem);
248 list_del_init(&sd->s_sibling);
251 simple_rmdir(parent->d_inode,d);
253 pr_debug(" o %s removing done (%d)\n",d->d_name.name,
254 atomic_read(&d->d_count));
256 up(&parent->d_inode->i_sem);
260 void sysfs_remove_subdir(struct dentry * d)
267 * sysfs_remove_dir - remove an object's directory.
270 * The only thing special about this is that we remove any files in
271 * the directory before we remove the directory, and we've inlined
272 * what used to be sysfs_rmdir() below, instead of calling separately.
275 void sysfs_remove_dir(struct kobject * kobj)
277 struct dentry * dentry = dget(kobj->dentry);
278 struct sysfs_dirent * parent_sd;
279 struct sysfs_dirent * sd, * tmp;
284 pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
285 down(&dentry->d_inode->i_sem);
286 parent_sd = dentry->d_fsdata;
287 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
288 if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
290 list_del_init(&sd->s_sibling);
291 sysfs_drop_dentry(sd, dentry);
294 up(&dentry->d_inode->i_sem);
298 * Drop reference from dget() on entrance.
303 int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
306 struct dentry * new_dentry, * parent;
308 if (!strcmp(kobject_name(kobj), new_name))
314 down_write(&sysfs_rename_sem);
315 parent = kobj->parent->dentry;
317 down(&parent->d_inode->i_sem);
319 new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
320 if (!IS_ERR(new_dentry)) {
321 if (!new_dentry->d_inode) {
322 error = kobject_set_name(kobj, "%s", new_name);
324 d_add(new_dentry, NULL);
325 d_move(kobj->dentry, new_dentry);
333 up(&parent->d_inode->i_sem);
334 up_write(&sysfs_rename_sem);
339 static int sysfs_dir_open(struct inode *inode, struct file *file)
341 struct dentry * dentry = file->f_dentry;
342 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
344 down(&dentry->d_inode->i_sem);
345 file->private_data = sysfs_new_dirent(parent_sd, NULL);
346 up(&dentry->d_inode->i_sem);
348 return file->private_data ? 0 : -ENOMEM;
352 static int sysfs_dir_close(struct inode *inode, struct file *file)
354 struct dentry * dentry = file->f_dentry;
355 struct sysfs_dirent * cursor = file->private_data;
357 down(&dentry->d_inode->i_sem);
358 list_del_init(&cursor->s_sibling);
359 up(&dentry->d_inode->i_sem);
361 release_sysfs_dirent(cursor);
366 /* Relationship between s_mode and the DT_xxx types */
367 static inline unsigned char dt_type(struct sysfs_dirent *sd)
369 return (sd->s_mode >> 12) & 15;
372 static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
374 struct dentry *dentry = filp->f_dentry;
375 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
376 struct sysfs_dirent *cursor = filp->private_data;
377 struct list_head *p, *q = &cursor->s_sibling;
383 ino = dentry->d_inode->i_ino;
384 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
390 ino = parent_ino(dentry);
391 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
397 if (filp->f_pos == 2) {
399 list_add(q, &parent_sd->s_children);
401 for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
402 struct sysfs_dirent *next;
406 next = list_entry(p, struct sysfs_dirent,
408 if (!next->s_element)
411 name = sysfs_get_name(next);
414 ino = next->s_dentry->d_inode->i_ino;
416 ino = iunique(sysfs_sb, 2);
418 if (filldir(dirent, name, len, filp->f_pos, ino,
431 static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
433 struct dentry * dentry = file->f_dentry;
435 down(&dentry->d_inode->i_sem);
438 offset += file->f_pos;
443 up(&file->f_dentry->d_inode->i_sem);
446 if (offset != file->f_pos) {
447 file->f_pos = offset;
448 if (file->f_pos >= 2) {
449 struct sysfs_dirent *sd = dentry->d_fsdata;
450 struct sysfs_dirent *cursor = file->private_data;
452 loff_t n = file->f_pos - 2;
454 list_del(&cursor->s_sibling);
455 p = sd->s_children.next;
456 while (n && p != &sd->s_children) {
457 struct sysfs_dirent *next;
458 next = list_entry(p, struct sysfs_dirent,
464 list_add_tail(&cursor->s_sibling, p);
467 up(&dentry->d_inode->i_sem);
471 struct file_operations sysfs_dir_operations = {
472 .open = sysfs_dir_open,
473 .release = sysfs_dir_close,
474 .llseek = sysfs_dir_lseek,
475 .read = generic_read_dir,
476 .readdir = sysfs_readdir,
479 EXPORT_SYMBOL_GPL(sysfs_create_dir);
480 EXPORT_SYMBOL_GPL(sysfs_remove_dir);
481 EXPORT_SYMBOL_GPL(sysfs_rename_dir);