[linux.git] / fs / sysfs / dir.c

/*
 * dir.c - Operations for sysfs directories.
 */

#undef DEBUG

#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/namei.h>
#include "sysfs.h"

DECLARE_RWSEM(sysfs_rename_sem);

static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
{
	struct sysfs_dirent * sd = dentry->d_fsdata;

	if (sd) {
		BUG_ON(sd->s_dentry != dentry);
		sd->s_dentry = NULL;
		sysfs_put(sd);
	}
	iput(inode);
}

static struct dentry_operations sysfs_dentry_ops = {
	.d_iput		= sysfs_d_iput,
};

/*
 * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
 */
static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
						void * element)
{
	struct sysfs_dirent * sd;

	sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
	if (!sd)
		return NULL;

	memset(sd, 0, sizeof(*sd));
	atomic_set(&sd->s_count, 1);
	INIT_LIST_HEAD(&sd->s_children);
	list_add(&sd->s_sibling, &parent_sd->s_children);
	sd->s_element = element;

	return sd;
}

int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
			void * element, umode_t mode, int type)
{
	struct sysfs_dirent * sd;

	sd = sysfs_new_dirent(parent_sd, element);
	if (!sd)
		return -ENOMEM;

	sd->s_mode = mode;
	sd->s_type = type;
	sd->s_dentry = dentry;
	if (dentry) {
		dentry->d_fsdata = sysfs_get(sd);
		dentry->d_op = &sysfs_dentry_ops;
	}

	return 0;
}

static int init_dir(struct inode * inode)
{
	inode->i_op = &sysfs_dir_inode_operations;
	inode->i_fop = &sysfs_dir_operations;

	/* directory inodes start off with i_nlink == 2 (for "." entry) */
	inode->i_nlink++;
	return 0;
}

static int init_file(struct inode * inode)
{
	inode->i_size = PAGE_SIZE;
	inode->i_fop = &sysfs_file_operations;
	return 0;
}

static int init_symlink(struct inode * inode)
{
	inode->i_op = &sysfs_symlink_inode_operations;
	return 0;
}

static int create_dir(struct kobject * k, struct dentry * p,
		      const char * n, struct dentry ** d)
{
	int error;
	umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;

	mutex_lock(&p->d_inode->i_mutex);
	*d = lookup_one_len(n, p, strlen(n));
	if (!IS_ERR(*d)) {
		error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
		if (!error) {
			error = sysfs_create(*d, mode, init_dir);
			if (!error) {
				p->d_inode->i_nlink++;
				(*d)->d_op = &sysfs_dentry_ops;
				d_rehash(*d);
			}
		}
		if (error && (error != -EEXIST)) {
			struct sysfs_dirent *sd = (*d)->d_fsdata;
			if (sd) {
 				list_del_init(&sd->s_sibling);
				sysfs_put(sd);
			}
			d_drop(*d);
		}
		dput(*d);
	} else
		error = PTR_ERR(*d);
	mutex_unlock(&p->d_inode->i_mutex);
	return error;
}


int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
{
	return create_dir(k,k->dentry,n,d);
}

/**
 *	sysfs_create_dir - create a directory for an object.
 *	@parent:	parent parent object.
 *	@kobj:		object we're creating directory for. 
 */

int sysfs_create_dir(struct kobject * kobj)
{
	struct dentry * dentry = NULL;
	struct dentry * parent;
	int error = 0;

	BUG_ON(!kobj);

	if (kobj->parent)
		parent = kobj->parent->dentry;
	else if (sysfs_mount && sysfs_mount->mnt_sb)
		parent = sysfs_mount->mnt_sb->s_root;
	else
		return -EFAULT;

	error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
	if (!error)
		kobj->dentry = dentry;
	return error;
}

/* attaches attribute's sysfs_dirent to the dentry corresponding to the
 * attribute file
 */
static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
{
	struct attribute * attr = NULL;
	struct bin_attribute * bin_attr = NULL;
	int (* init) (struct inode *) = NULL;
	int error = 0;

        if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
                bin_attr = sd->s_element;
                attr = &bin_attr->attr;
        } else {
                attr = sd->s_element;
                init = init_file;
        }

	dentry->d_fsdata = sysfs_get(sd);
	sd->s_dentry = dentry;
	error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
	if (error) {
		sysfs_put(sd);
		return error;
	}

        if (bin_attr) {
		dentry->d_inode->i_size = bin_attr->size;
		dentry->d_inode->i_fop = &bin_fops;
	}
	dentry->d_op = &sysfs_dentry_ops;
	d_rehash(dentry);

	return 0;
}

static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
{
	int err = 0;

	dentry->d_fsdata = sysfs_get(sd);
	sd->s_dentry = dentry;
	err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
	if (!err) {
		dentry->d_op = &sysfs_dentry_ops;
		d_rehash(dentry);
	} else
		sysfs_put(sd);

	return err;
}

static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
				struct nameidata *nd)
{
	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
	struct sysfs_dirent * sd;
	int err = 0;

	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
		if (sd->s_type & SYSFS_NOT_PINNED) {
			const unsigned char * name = sysfs_get_name(sd);

			if (strcmp(name, dentry->d_name.name))
				continue;

			if (sd->s_type & SYSFS_KOBJ_LINK)
				err = sysfs_attach_link(sd, dentry);
			else
				err = sysfs_attach_attr(sd, dentry);
			break;
		}
	}

	return ERR_PTR(err);
}

struct inode_operations sysfs_dir_inode_operations = {
	.lookup		= sysfs_lookup,
	.setattr	= sysfs_setattr,
};

static void remove_dir(struct dentry * d)
{
	struct dentry * parent = dget(d->d_parent);
	struct sysfs_dirent * sd;

	mutex_lock(&parent->d_inode->i_mutex);
	d_delete(d);
	sd = d->d_fsdata;
 	list_del_init(&sd->s_sibling);
	sysfs_put(sd);
	if (d->d_inode)
		simple_rmdir(parent->d_inode,d);

	pr_debug(" o %s removing done (%d)\n",d->d_name.name,
		 atomic_read(&d->d_count));

	mutex_unlock(&parent->d_inode->i_mutex);
	dput(parent);
}

void sysfs_remove_subdir(struct dentry * d)
{
	remove_dir(d);
}


/**
 *	sysfs_remove_dir - remove an object's directory.
 *	@kobj:	object. 
 *
 *	The only thing special about this is that we remove any files in 
 *	the directory before we remove the directory, and we've inlined
 *	what used to be sysfs_rmdir() below, instead of calling separately.
 */

void sysfs_remove_dir(struct kobject * kobj)
{
	struct dentry * dentry = dget(kobj->dentry);
	struct sysfs_dirent * parent_sd;
	struct sysfs_dirent * sd, * tmp;

	if (!dentry)
		return;

	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
	mutex_lock(&dentry->d_inode->i_mutex);
	parent_sd = dentry->d_fsdata;
	list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
		if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
			continue;
		list_del_init(&sd->s_sibling);
		sysfs_drop_dentry(sd, dentry);
		sysfs_put(sd);
	}
	mutex_unlock(&dentry->d_inode->i_mutex);

	remove_dir(dentry);
	/**
	 * Drop reference from dget() on entrance.
	 */
	dput(dentry);
}

int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
{
	int error = 0;
	struct dentry * new_dentry, * parent;

	if (!strcmp(kobject_name(kobj), new_name))
		return -EINVAL;

	if (!kobj->parent)
		return -EINVAL;

	down_write(&sysfs_rename_sem);
	parent = kobj->parent->dentry;

	mutex_lock(&parent->d_inode->i_mutex);

	new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
	if (!IS_ERR(new_dentry)) {
  		if (!new_dentry->d_inode) {
			error = kobject_set_name(kobj, "%s", new_name);
			if (!error) {
				d_add(new_dentry, NULL);
				d_move(kobj->dentry, new_dentry);
			}
			else
				d_drop(new_dentry);
		} else
			error = -EEXIST;
		dput(new_dentry);
	}
	mutex_unlock(&parent->d_inode->i_mutex);
	up_write(&sysfs_rename_sem);

	return error;
}

static int sysfs_dir_open(struct inode *inode, struct file *file)
{
	struct dentry * dentry = file->f_dentry;
	struct sysfs_dirent * parent_sd = dentry->d_fsdata;

	mutex_lock(&dentry->d_inode->i_mutex);
	file->private_data = sysfs_new_dirent(parent_sd, NULL);
	mutex_unlock(&dentry->d_inode->i_mutex);

	return file->private_data ? 0 : -ENOMEM;

}

static int sysfs_dir_close(struct inode *inode, struct file *file)
{
	struct dentry * dentry = file->f_dentry;
	struct sysfs_dirent * cursor = file->private_data;

	mutex_lock(&dentry->d_inode->i_mutex);
	list_del_init(&cursor->s_sibling);
	mutex_unlock(&dentry->d_inode->i_mutex);

	release_sysfs_dirent(cursor);

	return 0;
}

/* Relationship between s_mode and the DT_xxx types */
static inline unsigned char dt_type(struct sysfs_dirent *sd)
{
	return (sd->s_mode >> 12) & 15;
}

static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
	struct dentry *dentry = filp->f_dentry;
	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
	struct sysfs_dirent *cursor = filp->private_data;
	struct list_head *p, *q = &cursor->s_sibling;
	ino_t ino;
	int i = filp->f_pos;

	switch (i) {
		case 0:
			ino = dentry->d_inode->i_ino;
			if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
				break;
			filp->f_pos++;
			i++;
			/* fallthrough */
		case 1:
			ino = parent_ino(dentry);
			if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
				break;
			filp->f_pos++;
			i++;
			/* fallthrough */
		default:
			if (filp->f_pos == 2) {
				list_del(q);
				list_add(q, &parent_sd->s_children);
			}
			for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
				struct sysfs_dirent *next;
				const char * name;
				int len;

				next = list_entry(p, struct sysfs_dirent,
						   s_sibling);
				if (!next->s_element)
					continue;

				name = sysfs_get_name(next);
				len = strlen(name);
				if (next->s_dentry)
					ino = next->s_dentry->d_inode->i_ino;
				else
					ino = iunique(sysfs_sb, 2);

				if (filldir(dirent, name, len, filp->f_pos, ino,
						 dt_type(next)) < 0)
					return 0;

				list_del(q);
				list_add(q, p);
				p = q;
				filp->f_pos++;
			}
	}
	return 0;
}

static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
{
	struct dentry * dentry = file->f_dentry;

	mutex_lock(&dentry->d_inode->i_mutex);
	switch (origin) {
		case 1:
			offset += file->f_pos;
		case 0:
			if (offset >= 0)
				break;
		default:
			mutex_unlock(&file->f_dentry->d_inode->i_mutex);
			return -EINVAL;
	}
	if (offset != file->f_pos) {
		file->f_pos = offset;
		if (file->f_pos >= 2) {
			struct sysfs_dirent *sd = dentry->d_fsdata;
			struct sysfs_dirent *cursor = file->private_data;
			struct list_head *p;
			loff_t n = file->f_pos - 2;

			list_del(&cursor->s_sibling);
			p = sd->s_children.next;
			while (n && p != &sd->s_children) {
				struct sysfs_dirent *next;
				next = list_entry(p, struct sysfs_dirent,
						   s_sibling);
				if (next->s_element)
					n--;
				p = p->next;
			}
			list_add_tail(&cursor->s_sibling, p);
		}
	}
	mutex_unlock(&dentry->d_inode->i_mutex);
	return offset;
}

struct file_operations sysfs_dir_operations = {
	.open		= sysfs_dir_open,
	.release	= sysfs_dir_close,
	.llseek		= sysfs_dir_lseek,
	.read		= generic_read_dir,
	.readdir	= sysfs_readdir,
};

EXPORT_SYMBOL_GPL(sysfs_create_dir);
EXPORT_SYMBOL_GPL(sysfs_remove_dir);
EXPORT_SYMBOL_GPL(sysfs_rename_dir);
Commit	Line	Data
1da177e4 LT	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>
5f45f1a7	11	#include <linux/namei.h>
1da177e4 LT	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
	53	int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
	54	void * element, umode_t mode, int type)
	55	{
	56	struct sysfs_dirent * sd;
	57
	58	sd = sysfs_new_dirent(parent_sd, element);
	59	if (!sd)
	60	return -ENOMEM;
	61
	62	sd->s_mode = mode;
	63	sd->s_type = type;
	64	sd->s_dentry = dentry;
	65	if (dentry) {
	66	dentry->d_fsdata = sysfs_get(sd);
	67	dentry->d_op = &sysfs_dentry_ops;
	68	}
	69
	70	return 0;
	71	}
	72
	73	static int init_dir(struct inode * inode)
	74	{
	75	inode->i_op = &sysfs_dir_inode_operations;
76	inode->i_fop = &sysfs_dir_operations;
77
78	/* directory inodes start off with i_nlink == 2 (for "." entry) */
79	inode->i_nlink++;
80	return 0;
81	}
82
83	static int init_file(struct inode * inode)
84	{
85	inode->i_size = PAGE_SIZE;
86	inode->i_fop = &sysfs_file_operations;
87	return 0;
88	}
89
90	static int init_symlink(struct inode * inode)
91	{
92	inode->i_op = &sysfs_symlink_inode_operations;
93	return 0;
94	}
95
96	static int create_dir(struct kobject * k, struct dentry * p,
97	const char * n, struct dentry ** d)
98	{
99	int error;
100	umode_t mode = S_IFDIR\| S_IRWXU \| S_IRUGO \| S_IXUGO;
101
1b1dcc1b	102	mutex_lock(&p->d_inode->i_mutex);
5f45f1a7	103	*d = lookup_one_len(n, p, strlen(n));
1da177e4	104	if (!IS_ERR(*d)) {
6fa5c828	105	error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
1da177e4	106	if (!error) {
6fa5c828	107	error = sysfs_create(*d, mode, init_dir);
1da177e4 LT	108	if (!error) {
	109	p->d_inode->i_nlink++;
	110	(*d)->d_op = &sysfs_dentry_ops;
	111	d_rehash(*d);
	112	}
	113	}
6fa5c828	114	if (error && (error != -EEXIST)) {
e80a5dea SR	115	struct sysfs_dirent sd = (d)->d_fsdata;
	116	if (sd) {
	117	list_del_init(&sd->s_sibling);
	118	sysfs_put(sd);
	119	}
1da177e4	120	d_drop(*d);
6fa5c828	121	}
1da177e4 LT	122	dput(*d);
	123	} else
	124	error = PTR_ERR(*d);
1b1dcc1b	125	mutex_unlock(&p->d_inode->i_mutex);
1da177e4 LT	126	return error;
	127	}
	128
	129
	130	int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
	131	{
	132	return create_dir(k,k->dentry,n,d);
	133	}
	134
	135	/**
	136	* sysfs_create_dir - create a directory for an object.
	137	* @parent: parent parent object.
	138	* @kobj: object we're creating directory for.
	139	*/
	140
	141	int sysfs_create_dir(struct kobject * kobj)
	142	{
	143	struct dentry * dentry = NULL;
	144	struct dentry * parent;
	145	int error = 0;
	146
	147	BUG_ON(!kobj);
	148
	149	if (kobj->parent)
	150	parent = kobj->parent->dentry;
	151	else if (sysfs_mount && sysfs_mount->mnt_sb)
	152	parent = sysfs_mount->mnt_sb->s_root;
	153	else
	154	return -EFAULT;
	155
	156	error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
	157	if (!error)
	158	kobj->dentry = dentry;
	159	return error;
	160	}
	161
	162	/* attaches attribute's sysfs_dirent to the dentry corresponding to the
	163	* attribute file
	164	*/
	165	static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
	166	{
	167	struct attribute * attr = NULL;
	168	struct bin_attribute * bin_attr = NULL;
	169	int (* init) (struct inode *) = NULL;
	170	int error = 0;
	171
	172	if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
	173	bin_attr = sd->s_element;
	174	attr = &bin_attr->attr;
	175	} else {
	176	attr = sd->s_element;
	177	init = init_file;
	178	}
	179
6fa5c828 MS	180	dentry->d_fsdata = sysfs_get(sd);
6fa5c828 MS	181	sd->s_dentry = dentry;
1da177e4	182	error = sysfs_create(dentry, (attr->mode & S_IALLUGO) \| S_IFREG, init);
6fa5c828 MS	183	if (error) {
6fa5c828 MS	184	sysfs_put(sd);
1da177e4	185	return error;
6fa5c828	186	}
1da177e4 LT	187
	188	if (bin_attr) {
	189	dentry->d_inode->i_size = bin_attr->size;
	190	dentry->d_inode->i_fop = &bin_fops;
	191	}
	192	dentry->d_op = &sysfs_dentry_ops;
1da177e4 LT	193	d_rehash(dentry);
	194
	195	return 0;
	196	}
	197
	198	static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
	199	{
	200	int err = 0;
	201
6fa5c828 MS	202	dentry->d_fsdata = sysfs_get(sd);
6fa5c828 MS	203	sd->s_dentry = dentry;
1da177e4 LT	204	err = sysfs_create(dentry, S_IFLNK\|S_IRWXUGO, init_symlink);
	205	if (!err) {
	206	dentry->d_op = &sysfs_dentry_ops;
1da177e4	207	d_rehash(dentry);
6fa5c828 MS	208	} else
	209	sysfs_put(sd);
	210
1da177e4 LT	211	return err;
	212	}
	213
	214	static struct dentry * sysfs_lookup(struct inode dir, struct dentry dentry,
	215	struct nameidata *nd)
	216	{
	217	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
	218	struct sysfs_dirent * sd;
	219	int err = 0;
	220
	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);
	224
	225	if (strcmp(name, dentry->d_name.name))
	226	continue;
	227
	228	if (sd->s_type & SYSFS_KOBJ_LINK)
	229	err = sysfs_attach_link(sd, dentry);
	230	else
	231	err = sysfs_attach_attr(sd, dentry);
	232	break;
	233	}
	234	}
	235
	236	return ERR_PTR(err);
	237	}
	238
	239	struct inode_operations sysfs_dir_inode_operations = {
	240	.lookup = sysfs_lookup,
988d186d	241	.setattr = sysfs_setattr,
1da177e4 LT	242	};
	243
	244	static void remove_dir(struct dentry * d)
	245	{
	246	struct dentry * parent = dget(d->d_parent);
	247	struct sysfs_dirent * sd;
	248
1b1dcc1b	249	mutex_lock(&parent->d_inode->i_mutex);
1da177e4 LT	250	d_delete(d);
	251	sd = d->d_fsdata;
	252	list_del_init(&sd->s_sibling);
	253	sysfs_put(sd);
	254	if (d->d_inode)
	255	simple_rmdir(parent->d_inode,d);
	256
	257	pr_debug(" o %s removing done (%d)\n",d->d_name.name,
	258	atomic_read(&d->d_count));
	259
1b1dcc1b	260	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	261	dput(parent);
	262	}
	263
	264	void sysfs_remove_subdir(struct dentry * d)
	265	{
	266	remove_dir(d);
	267	}
	268
	269
	270	/**
	271	* sysfs_remove_dir - remove an object's directory.
	272	* @kobj: object.
	273	*
	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.
	277	*/
	278
	279	void sysfs_remove_dir(struct kobject * kobj)
	280	{
	281	struct dentry * dentry = dget(kobj->dentry);
	282	struct sysfs_dirent * parent_sd;
	283	struct sysfs_dirent * sd, * tmp;
	284
	285	if (!dentry)
	286	return;
	287
	288	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
1b1dcc1b	289	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4 LT	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))
	293	continue;
	294	list_del_init(&sd->s_sibling);
	295	sysfs_drop_dentry(sd, dentry);
	296	sysfs_put(sd);
	297	}
1b1dcc1b	298	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	299
	300	remove_dir(dentry);
	301	/**
	302	* Drop reference from dget() on entrance.
	303	*/
	304	dput(dentry);
	305	}
	306
	307	int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
	308	{
	309	int error = 0;
	310	struct dentry * new_dentry, * parent;
	311
	312	if (!strcmp(kobject_name(kobj), new_name))
	313	return -EINVAL;
	314
	315	if (!kobj->parent)
	316	return -EINVAL;
	317
	318	down_write(&sysfs_rename_sem);
	319	parent = kobj->parent->dentry;
	320
1b1dcc1b	321	mutex_lock(&parent->d_inode->i_mutex);
1da177e4	322
5f45f1a7	323	new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
1da177e4 LT	324	if (!IS_ERR(new_dentry)) {
	325	if (!new_dentry->d_inode) {
	326	error = kobject_set_name(kobj, "%s", new_name);
	327	if (!error) {
	328	d_add(new_dentry, NULL);
	329	d_move(kobj->dentry, new_dentry);
	330	}
	331	else
	332	d_drop(new_dentry);
	333	} else
	334	error = -EEXIST;
	335	dput(new_dentry);
	336	}
1b1dcc1b	337	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	338	up_write(&sysfs_rename_sem);
	339
	340	return error;
	341	}
	342
	343	static int sysfs_dir_open(struct inode inode, struct file file)
	344	{
	345	struct dentry * dentry = file->f_dentry;
	346	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
	347
1b1dcc1b	348	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4	349	file->private_data = sysfs_new_dirent(parent_sd, NULL);
1b1dcc1b	350	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	351
	352	return file->private_data ? 0 : -ENOMEM;
	353
	354	}
	355
	356	static int sysfs_dir_close(struct inode inode, struct file file)
	357	{
	358	struct dentry * dentry = file->f_dentry;
	359	struct sysfs_dirent * cursor = file->private_data;
	360
1b1dcc1b	361	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4	362	list_del_init(&cursor->s_sibling);
1b1dcc1b	363	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	364
	365	release_sysfs_dirent(cursor);
	366
	367	return 0;
	368	}
	369
	370	/* Relationship between s_mode and the DT_xxx types */
	371	static inline unsigned char dt_type(struct sysfs_dirent *sd)
	372	{
	373	return (sd->s_mode >> 12) & 15;
	374	}
	375
	376	static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
	377	{
	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;
	382	ino_t ino;
	383	int i = filp->f_pos;
	384
	385	switch (i) {
	386	case 0:
	387	ino = dentry->d_inode->i_ino;
	388	if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
	389	break;
	390	filp->f_pos++;
	391	i++;
	392	/* fallthrough */
	393	case 1:
	394	ino = parent_ino(dentry);
	395	if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
	396	break;
	397	filp->f_pos++;
	398	i++;
	399	/* fallthrough */
	400	default:
	401	if (filp->f_pos == 2) {
	402	list_del(q);
	403	list_add(q, &parent_sd->s_children);
	404	}
	405	for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
	406	struct sysfs_dirent *next;
	407	const char * name;
	408	int len;
	409
	410	next = list_entry(p, struct sysfs_dirent,
	411	s_sibling);
	412	if (!next->s_element)
	413	continue;
	414
	415	name = sysfs_get_name(next);
	416	len = strlen(name);
	417	if (next->s_dentry)
	418	ino = next->s_dentry->d_inode->i_ino;
	419	else
	420	ino = iunique(sysfs_sb, 2);
	421
	422	if (filldir(dirent, name, len, filp->f_pos, ino,
	423	dt_type(next)) < 0)
	424	return 0;
	425
	426	list_del(q);
	427	list_add(q, p);
428	p = q;
429	filp->f_pos++;
430	}
431	}
432	return 0;
433	}
434
435	static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
436	{
437	struct dentry * dentry = file->f_dentry;
438
1b1dcc1b	439	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4 LT	440	switch (origin) {
	441	case 1:
	442	offset += file->f_pos;
	443	case 0:
	444	if (offset >= 0)
	445	break;
	446	default:
1b1dcc1b	447	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
1da177e4 LT	448	return -EINVAL;
	449	}
	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;
	455	struct list_head *p;
	456	loff_t n = file->f_pos - 2;
	457
	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,
	463	s_sibling);
	464	if (next->s_element)
	465	n--;
	466	p = p->next;
	467	}
	468	list_add_tail(&cursor->s_sibling, p);
	469	}
	470	}
1b1dcc1b	471	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	472	return offset;
	473	}
	474
	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,
	481	};
	482
	483	EXPORT_SYMBOL_GPL(sysfs_create_dir);
	484	EXPORT_SYMBOL_GPL(sysfs_remove_dir);
	485	EXPORT_SYMBOL_GPL(sysfs_rename_dir);