[mirror_ubuntu-bionic-kernel.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);
	atomic_set(&sd->s_event, 1);
	INIT_LIST_HEAD(&sd->s_children);
	list_add(&sd->s_sibling, &parent_sd->s_children);
	sd->s_element = element;

	return sd;
}

/*
 *
 * Return -EEXIST if there is already a sysfs element with the same name for
 * the same parent.
 *
 * called with parent inode's i_mutex held
 */
int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
			  const unsigned char *new)
{
	struct sysfs_dirent * sd;

	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
		if (sd->s_element) {
			const unsigned char *existing = sysfs_get_name(sd);
			if (strcmp(existing, new))
				continue;
			else
				return -EEXIST;
		}
	}

	return 0;
}


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) */
	inc_nlink(inode);
	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)) {
 		if (sysfs_dirent_exist(p->d_fsdata, n))
  			error = -EEXIST;
  		else
			error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
								SYSFS_DIR);
		if (!error) {
			error = sysfs_create(*d, mode, init_dir);
			if (!error) {
				inc_nlink(p->d_inode);
				(*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);
	kobj->dentry = NULL;
}

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;
}

int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent)
{
	struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry;
	struct sysfs_dirent *new_parent_sd, *sd;
	int error;

	old_parent_dentry = kobj->parent ?
		kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;
	new_parent_dentry = new_parent ?
		new_parent->dentry : sysfs_mount->mnt_sb->s_root;

again:
	mutex_lock(&old_parent_dentry->d_inode->i_mutex);
	if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) {
		mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
		goto again;
	}

	new_parent_sd = new_parent_dentry->d_fsdata;
	sd = kobj->dentry->d_fsdata;

	new_dentry = lookup_one_len(kobj->name, new_parent_dentry,
				    strlen(kobj->name));
	if (IS_ERR(new_dentry)) {
		error = PTR_ERR(new_dentry);
		goto out;
	} else
		error = 0;
	d_add(new_dentry, NULL);
	d_move(kobj->dentry, new_dentry);
	dput(new_dentry);

	/* Remove from old parent's list and insert into new parent's list. */
	list_del_init(&sd->s_sibling);
	list_add(&sd->s_sibling, &new_parent_sd->s_children);

out:
	mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
	mutex_unlock(&old_parent_dentry->d_inode->i_mutex);

	return error;
}

static int sysfs_dir_open(struct inode *inode, struct file *file)
{
	struct dentry * dentry = file->f_path.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_path.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_path.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_move(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_move(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_path.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_path.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;
}

const 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,
};
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);
eea3f891	46	atomic_set(&sd->s_event, 1);
1da177e4 LT	47	INIT_LIST_HEAD(&sd->s_children);
	48	list_add(&sd->s_sibling, &parent_sd->s_children);
	49	sd->s_element = element;
	50
	51	return sd;
	52	}
	53
a580290c	54	/*
c516865c MS	55	*
	56	* Return -EEXIST if there is already a sysfs element with the same name for
	57	* the same parent.
	58	*
	59	* called with parent inode's i_mutex held
	60	*/
	61	int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
	62	const unsigned char *new)
	63	{
	64	struct sysfs_dirent * sd;
	65
	66	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
	67	if (sd->s_element) {
	68	const unsigned char *existing = sysfs_get_name(sd);
	69	if (strcmp(existing, new))
	70	continue;
	71	else
	72	return -EEXIST;
	73	}
	74	}
	75
	76	return 0;
	77	}
	78
	79
1da177e4 LT	80	int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
	81	void * element, umode_t mode, int type)
	82	{
	83	struct sysfs_dirent * sd;
	84
	85	sd = sysfs_new_dirent(parent_sd, element);
	86	if (!sd)
	87	return -ENOMEM;
	88
	89	sd->s_mode = mode;
	90	sd->s_type = type;
	91	sd->s_dentry = dentry;
	92	if (dentry) {
	93	dentry->d_fsdata = sysfs_get(sd);
	94	dentry->d_op = &sysfs_dentry_ops;
	95	}
	96
	97	return 0;
	98	}
	99
	100	static int init_dir(struct inode * inode)
	101	{
	102	inode->i_op = &sysfs_dir_inode_operations;
	103	inode->i_fop = &sysfs_dir_operations;
	104
	105	/* directory inodes start off with i_nlink == 2 (for "." entry) */
d8c76e6f	106	inc_nlink(inode);
1da177e4 LT	107	return 0;
	108	}
	109
	110	static int init_file(struct inode * inode)
	111	{
	112	inode->i_size = PAGE_SIZE;
	113	inode->i_fop = &sysfs_file_operations;
	114	return 0;
	115	}
	116
	117	static int init_symlink(struct inode * inode)
	118	{
	119	inode->i_op = &sysfs_symlink_inode_operations;
	120	return 0;
	121	}
	122
	123	static int create_dir(struct kobject * k, struct dentry * p,
	124	const char * n, struct dentry ** d)
	125	{
	126	int error;
	127	umode_t mode = S_IFDIR\| S_IRWXU \| S_IRUGO \| S_IXUGO;
	128
1b1dcc1b	129	mutex_lock(&p->d_inode->i_mutex);
5f45f1a7	130	*d = lookup_one_len(n, p, strlen(n));
1da177e4	131	if (!IS_ERR(*d)) {
c516865c MS	132	if (sysfs_dirent_exist(p->d_fsdata, n))
	133	error = -EEXIST;
	134	else
	135	error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
	136	SYSFS_DIR);
1da177e4	137	if (!error) {
6fa5c828	138	error = sysfs_create(*d, mode, init_dir);
1da177e4	139	if (!error) {
d8c76e6f	140	inc_nlink(p->d_inode);
1da177e4 LT	141	(*d)->d_op = &sysfs_dentry_ops;
	142	d_rehash(*d);
	143	}
	144	}
6fa5c828	145	if (error && (error != -EEXIST)) {
e80a5dea SR	146	struct sysfs_dirent sd = (d)->d_fsdata;
	147	if (sd) {
	148	list_del_init(&sd->s_sibling);
	149	sysfs_put(sd);
	150	}
1da177e4	151	d_drop(*d);
6fa5c828	152	}
1da177e4 LT	153	dput(*d);
	154	} else
	155	error = PTR_ERR(*d);
1b1dcc1b	156	mutex_unlock(&p->d_inode->i_mutex);
1da177e4 LT	157	return error;
	158	}
	159
	160
	161	int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
	162	{
	163	return create_dir(k,k->dentry,n,d);
	164	}
	165
	166	/**
	167	* sysfs_create_dir - create a directory for an object.
	168	* @parent: parent parent object.
	169	* @kobj: object we're creating directory for.
	170	*/
	171
	172	int sysfs_create_dir(struct kobject * kobj)
	173	{
	174	struct dentry * dentry = NULL;
	175	struct dentry * parent;
	176	int error = 0;
	177
	178	BUG_ON(!kobj);
	179
	180	if (kobj->parent)
	181	parent = kobj->parent->dentry;
	182	else if (sysfs_mount && sysfs_mount->mnt_sb)
	183	parent = sysfs_mount->mnt_sb->s_root;
	184	else
	185	return -EFAULT;
	186
	187	error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
	188	if (!error)
	189	kobj->dentry = dentry;
	190	return error;
	191	}
	192
	193	/* attaches attribute's sysfs_dirent to the dentry corresponding to the
	194	* attribute file
	195	*/
	196	static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
	197	{
	198	struct attribute * attr = NULL;
	199	struct bin_attribute * bin_attr = NULL;
	200	int (* init) (struct inode *) = NULL;
	201	int error = 0;
	202
	203	if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
	204	bin_attr = sd->s_element;
	205	attr = &bin_attr->attr;
	206	} else {
	207	attr = sd->s_element;
	208	init = init_file;
	209	}
	210
6fa5c828 MS	211	dentry->d_fsdata = sysfs_get(sd);
6fa5c828 MS	212	sd->s_dentry = dentry;
1da177e4	213	error = sysfs_create(dentry, (attr->mode & S_IALLUGO) \| S_IFREG, init);
6fa5c828 MS	214	if (error) {
6fa5c828 MS	215	sysfs_put(sd);
1da177e4	216	return error;
6fa5c828	217	}
1da177e4 LT	218
	219	if (bin_attr) {
	220	dentry->d_inode->i_size = bin_attr->size;
	221	dentry->d_inode->i_fop = &bin_fops;
	222	}
	223	dentry->d_op = &sysfs_dentry_ops;
1da177e4 LT	224	d_rehash(dentry);
	225
	226	return 0;
	227	}
	228
	229	static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
	230	{
	231	int err = 0;
	232
6fa5c828 MS	233	dentry->d_fsdata = sysfs_get(sd);
6fa5c828 MS	234	sd->s_dentry = dentry;
1da177e4 LT	235	err = sysfs_create(dentry, S_IFLNK\|S_IRWXUGO, init_symlink);
	236	if (!err) {
	237	dentry->d_op = &sysfs_dentry_ops;
1da177e4	238	d_rehash(dentry);
6fa5c828 MS	239	} else
	240	sysfs_put(sd);
	241
1da177e4 LT	242	return err;
	243	}
	244
	245	static struct dentry * sysfs_lookup(struct inode dir, struct dentry dentry,
	246	struct nameidata *nd)
	247	{
	248	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
	249	struct sysfs_dirent * sd;
	250	int err = 0;
	251
	252	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
	253	if (sd->s_type & SYSFS_NOT_PINNED) {
	254	const unsigned char * name = sysfs_get_name(sd);
	255
	256	if (strcmp(name, dentry->d_name.name))
	257	continue;
	258
	259	if (sd->s_type & SYSFS_KOBJ_LINK)
	260	err = sysfs_attach_link(sd, dentry);
	261	else
	262	err = sysfs_attach_attr(sd, dentry);
	263	break;
	264	}
	265	}
	266
	267	return ERR_PTR(err);
	268	}
	269
	270	struct inode_operations sysfs_dir_inode_operations = {
	271	.lookup = sysfs_lookup,
988d186d	272	.setattr = sysfs_setattr,
1da177e4 LT	273	};
	274
	275	static void remove_dir(struct dentry * d)
	276	{
	277	struct dentry * parent = dget(d->d_parent);
	278	struct sysfs_dirent * sd;
	279
1b1dcc1b	280	mutex_lock(&parent->d_inode->i_mutex);
1da177e4 LT	281	d_delete(d);
	282	sd = d->d_fsdata;
	283	list_del_init(&sd->s_sibling);
	284	sysfs_put(sd);
	285	if (d->d_inode)
	286	simple_rmdir(parent->d_inode,d);
	287
	288	pr_debug(" o %s removing done (%d)\n",d->d_name.name,
	289	atomic_read(&d->d_count));
	290
1b1dcc1b	291	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	292	dput(parent);
	293	}
	294
	295	void sysfs_remove_subdir(struct dentry * d)
	296	{
	297	remove_dir(d);
	298	}
	299
	300
	301	/**
	302	* sysfs_remove_dir - remove an object's directory.
	303	* @kobj: object.
	304	*
	305	* The only thing special about this is that we remove any files in
	306	* the directory before we remove the directory, and we've inlined
	307	* what used to be sysfs_rmdir() below, instead of calling separately.
	308	*/
	309
	310	void sysfs_remove_dir(struct kobject * kobj)
	311	{
	312	struct dentry * dentry = dget(kobj->dentry);
	313	struct sysfs_dirent * parent_sd;
	314	struct sysfs_dirent * sd, * tmp;
	315
	316	if (!dentry)
	317	return;
	318
	319	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
1b1dcc1b	320	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4 LT	321	parent_sd = dentry->d_fsdata;
	322	list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
	323	if (!sd->s_element \|\| !(sd->s_type & SYSFS_NOT_PINNED))
	324	continue;
	325	list_del_init(&sd->s_sibling);
	326	sysfs_drop_dentry(sd, dentry);
	327	sysfs_put(sd);
	328	}
1b1dcc1b	329	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	330
	331	remove_dir(dentry);
	332	/**
	333	* Drop reference from dget() on entrance.
	334	*/
	335	dput(dentry);
641e6f30	336	kobj->dentry = NULL;
1da177e4 LT	337	}
	338
	339	int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
	340	{
	341	int error = 0;
	342	struct dentry * new_dentry, * parent;
	343
	344	if (!strcmp(kobject_name(kobj), new_name))
	345	return -EINVAL;
	346
	347	if (!kobj->parent)
	348	return -EINVAL;
	349
	350	down_write(&sysfs_rename_sem);
	351	parent = kobj->parent->dentry;
	352
1b1dcc1b	353	mutex_lock(&parent->d_inode->i_mutex);
1da177e4	354
5f45f1a7	355	new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
1da177e4 LT	356	if (!IS_ERR(new_dentry)) {
	357	if (!new_dentry->d_inode) {
	358	error = kobject_set_name(kobj, "%s", new_name);
	359	if (!error) {
	360	d_add(new_dentry, NULL);
	361	d_move(kobj->dentry, new_dentry);
	362	}
	363	else
	364	d_drop(new_dentry);
	365	} else
	366	error = -EEXIST;
	367	dput(new_dentry);
	368	}
1b1dcc1b	369	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	370	up_write(&sysfs_rename_sem);
	371
	372	return error;
	373	}
	374
8a82472f CH	375	int sysfs_move_dir(struct kobject kobj, struct kobject new_parent)
	376	{
	377	struct dentry old_parent_dentry, new_parent_dentry, *new_dentry;
	378	struct sysfs_dirent new_parent_sd, sd;
	379	int error;
	380
8a82472f CH	381	old_parent_dentry = kobj->parent ?
8a82472f CH	382	kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;
c744aeae CH	383	new_parent_dentry = new_parent ?
c744aeae CH	384	new_parent->dentry : sysfs_mount->mnt_sb->s_root;
8a82472f CH	385
	386	again:
	387	mutex_lock(&old_parent_dentry->d_inode->i_mutex);
	388	if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) {
	389	mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
	390	goto again;
	391	}
	392
	393	new_parent_sd = new_parent_dentry->d_fsdata;
	394	sd = kobj->dentry->d_fsdata;
	395
	396	new_dentry = lookup_one_len(kobj->name, new_parent_dentry,
	397	strlen(kobj->name));
	398	if (IS_ERR(new_dentry)) {
	399	error = PTR_ERR(new_dentry);
	400	goto out;
	401	} else
	402	error = 0;
	403	d_add(new_dentry, NULL);
	404	d_move(kobj->dentry, new_dentry);
	405	dput(new_dentry);
	406
	407	/* Remove from old parent's list and insert into new parent's list. */
	408	list_del_init(&sd->s_sibling);
	409	list_add(&sd->s_sibling, &new_parent_sd->s_children);
	410
	411	out:
	412	mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
	413	mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
	414
	415	return error;
	416	}
	417
1da177e4 LT	418	static int sysfs_dir_open(struct inode inode, struct file file)
1da177e4 LT	419	{
f427f5d5	420	struct dentry * dentry = file->f_path.dentry;
1da177e4 LT	421	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
1da177e4 LT	422
1b1dcc1b	423	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4	424	file->private_data = sysfs_new_dirent(parent_sd, NULL);
1b1dcc1b	425	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	426
	427	return file->private_data ? 0 : -ENOMEM;
	428
	429	}
	430
	431	static int sysfs_dir_close(struct inode inode, struct file file)
	432	{
f427f5d5	433	struct dentry * dentry = file->f_path.dentry;
1da177e4 LT	434	struct sysfs_dirent * cursor = file->private_data;
1da177e4 LT	435
1b1dcc1b	436	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4	437	list_del_init(&cursor->s_sibling);
1b1dcc1b	438	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	439
	440	release_sysfs_dirent(cursor);
	441
	442	return 0;
	443	}
	444
	445	/* Relationship between s_mode and the DT_xxx types */
	446	static inline unsigned char dt_type(struct sysfs_dirent *sd)
	447	{
	448	return (sd->s_mode >> 12) & 15;
	449	}
	450
	451	static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
	452	{
f427f5d5	453	struct dentry *dentry = filp->f_path.dentry;
1da177e4 LT	454	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
	455	struct sysfs_dirent *cursor = filp->private_data;
	456	struct list_head p, q = &cursor->s_sibling;
	457	ino_t ino;
	458	int i = filp->f_pos;
	459
	460	switch (i) {
	461	case 0:
	462	ino = dentry->d_inode->i_ino;
	463	if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
	464	break;
	465	filp->f_pos++;
	466	i++;
	467	/* fallthrough */
	468	case 1:
	469	ino = parent_ino(dentry);
	470	if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
	471	break;
	472	filp->f_pos++;
	473	i++;
	474	/* fallthrough */
	475	default:
1bfba4e8 AM	476	if (filp->f_pos == 2)
	477	list_move(q, &parent_sd->s_children);
	478
1da177e4 LT	479	for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
	480	struct sysfs_dirent *next;
	481	const char * name;
	482	int len;
	483
	484	next = list_entry(p, struct sysfs_dirent,
	485	s_sibling);
	486	if (!next->s_element)
	487	continue;
	488
	489	name = sysfs_get_name(next);
	490	len = strlen(name);
	491	if (next->s_dentry)
	492	ino = next->s_dentry->d_inode->i_ino;
	493	else
	494	ino = iunique(sysfs_sb, 2);
	495
	496	if (filldir(dirent, name, len, filp->f_pos, ino,
	497	dt_type(next)) < 0)
	498	return 0;
	499
1bfba4e8	500	list_move(q, p);
1da177e4 LT	501	p = q;
	502	filp->f_pos++;
	503	}
	504	}
	505	return 0;
	506	}
	507
	508	static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
	509	{
f427f5d5	510	struct dentry * dentry = file->f_path.dentry;
1da177e4	511
1b1dcc1b	512	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4 LT	513	switch (origin) {
	514	case 1:
	515	offset += file->f_pos;
	516	case 0:
	517	if (offset >= 0)
	518	break;
	519	default:
f427f5d5	520	mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
1da177e4 LT	521	return -EINVAL;
	522	}
	523	if (offset != file->f_pos) {
	524	file->f_pos = offset;
	525	if (file->f_pos >= 2) {
	526	struct sysfs_dirent *sd = dentry->d_fsdata;
	527	struct sysfs_dirent *cursor = file->private_data;
	528	struct list_head *p;
	529	loff_t n = file->f_pos - 2;
	530
	531	list_del(&cursor->s_sibling);
	532	p = sd->s_children.next;
	533	while (n && p != &sd->s_children) {
	534	struct sysfs_dirent *next;
	535	next = list_entry(p, struct sysfs_dirent,
	536	s_sibling);
	537	if (next->s_element)
	538	n--;
	539	p = p->next;
	540	}
	541	list_add_tail(&cursor->s_sibling, p);
	542	}
	543	}
1b1dcc1b	544	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	545	return offset;
	546	}
	547
4b6f5d20	548	const struct file_operations sysfs_dir_operations = {
1da177e4 LT	549	.open = sysfs_dir_open,
	550	.release = sysfs_dir_close,
	551	.llseek = sysfs_dir_lseek,
	552	.read = generic_read_dir,
	553	.readdir = sysfs_readdir,
	554	};