[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 <asm/semaphore.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(void * element)
{
	struct sysfs_dirent * sd;

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

	atomic_set(&sd->s_count, 1);
	atomic_set(&sd->s_event, 1);
	INIT_LIST_HEAD(&sd->s_children);
	INIT_LIST_HEAD(&sd->s_sibling);
	sd->s_element = element;

	return sd;
}

static void __sysfs_list_dirent(struct sysfs_dirent *parent_sd,
			      struct sysfs_dirent *sd)
{
	if (sd)
		list_add(&sd->s_sibling, &parent_sd->s_children);
}

static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent *parent_sd,
						void * element)
{
	struct sysfs_dirent *sd;
	sd = __sysfs_new_dirent(element);
	__sysfs_list_dirent(parent_sd, sd);
	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;
}


static struct sysfs_dirent *
__sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type)
{
	struct sysfs_dirent * sd;

	sd = __sysfs_new_dirent(element);
	if (!sd)
		goto out;

	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;
	}

out:
	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_make_dirent(dentry, element, mode, type);
	__sysfs_list_dirent(parent_sd, sd);

	return sd ? 0 : -ENOMEM;
}

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.
 *	@kobj:		object we're creating directory for. 
 *	@shadow_parent:	parent parent object.
 */

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

	BUG_ON(!kobj);

	if (shadow_parent)
		parent = shadow_parent;
	else 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);
}

const 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);
}


static void __sysfs_remove_dir(struct dentry *dentry)
{
	struct sysfs_dirent * parent_sd;
	struct sysfs_dirent * sd, * tmp;

	dget(dentry);
	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);
}

/**
 *	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)
{
	__sysfs_remove_dir(kobj->dentry);
	kobj->dentry = NULL;
}

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

	if (!new_parent)
		return -EFAULT;

	down_write(&sysfs_rename_sem);
	mutex_lock(&new_parent->d_inode->i_mutex);

	new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
	if (!IS_ERR(new_dentry)) {
		/* By allowing two different directories with the
		 * same d_parent we allow this routine to move
		 * between different shadows of the same directory
		 */
		if (kobj->dentry->d_parent->d_inode != new_parent->d_inode)
			return -EINVAL;
		else if (new_dentry->d_parent->d_inode != new_parent->d_inode)
			error = -EINVAL;
		else if (new_dentry == kobj->dentry)
			error = -EINVAL;
		else if (!new_dentry->d_inode) {
			error = kobject_set_name(kobj, "%s", new_name);
			if (!error) {
				struct sysfs_dirent *sd, *parent_sd;

				d_add(new_dentry, NULL);
				d_move(kobj->dentry, new_dentry);

				sd = kobj->dentry->d_fsdata;
				parent_sd = new_parent->d_fsdata;

				list_del_init(&sd->s_sibling);
				list_add(&sd->s_sibling, &parent_sd->s_children);
			}
			else
				d_drop(new_dentry);
		} else
			error = -EEXIST;
		dput(new_dentry);
	}
	mutex_unlock(&new_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;

	if (old_parent_dentry->d_inode == new_parent_dentry->d_inode)
		return 0;	/* nothing to move */
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;
}


/**
 *	sysfs_make_shadowed_dir - Setup so a directory can be shadowed
 *	@kobj:	object we're creating shadow of.
 */

int sysfs_make_shadowed_dir(struct kobject *kobj,
	void * (*follow_link)(struct dentry *, struct nameidata *))
{
	struct inode *inode;
	struct inode_operations *i_op;

	inode = kobj->dentry->d_inode;
	if (inode->i_op != &sysfs_dir_inode_operations)
		return -EINVAL;

	i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
	if (!i_op)
		return -ENOMEM;

	memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
	i_op->follow_link = follow_link;

	/* Locking of inode->i_op?
	 * Since setting i_op is a single word write and they
	 * are atomic we should be ok here.
	 */
	inode->i_op = i_op;
	return 0;
}

/**
 *	sysfs_create_shadow_dir - create a shadow directory for an object.
 *	@kobj:	object we're creating directory for.
 *
 *	sysfs_make_shadowed_dir must already have been called on this
 *	directory.
 */

struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
{
	struct sysfs_dirent *sd;
	struct dentry *parent, *dir, *shadow;
	struct inode *inode;

	dir = kobj->dentry;
	inode = dir->d_inode;
	parent = dir->d_parent;
	shadow = ERR_PTR(-EINVAL);
	if (!sysfs_is_shadowed_inode(inode))
		goto out;

	shadow = d_alloc(parent, &dir->d_name);
	if (!shadow)
		goto nomem;

	sd = __sysfs_make_dirent(shadow, kobj, inode->i_mode, SYSFS_DIR);
	if (!sd)
		goto nomem;

	d_instantiate(shadow, igrab(inode));
	inc_nlink(inode);
	inc_nlink(parent->d_inode);
	shadow->d_op = &sysfs_dentry_ops;

	dget(shadow);		/* Extra count - pin the dentry in core */

out:
	return shadow;
nomem:
	dput(shadow);
	shadow = ERR_PTR(-ENOMEM);
	goto out;
}

/**
 *	sysfs_remove_shadow_dir - remove an object's directory.
 *	@shadow: dentry of shadow directory
 *
 *	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_shadow_dir(struct dentry *shadow)
{
	__sysfs_remove_dir(shadow);
}

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>
94bebf4d	12	#include <asm/semaphore.h>
1da177e4 LT	13	#include "sysfs.h"
	14
	15	DECLARE_RWSEM(sysfs_rename_sem);
	16
	17	static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
	18	{
	19	struct sysfs_dirent * sd = dentry->d_fsdata;
	20
	21	if (sd) {
	22	BUG_ON(sd->s_dentry != dentry);
	23	sd->s_dentry = NULL;
	24	sysfs_put(sd);
	25	}
	26	iput(inode);
	27	}
	28
	29	static struct dentry_operations sysfs_dentry_ops = {
	30	.d_iput = sysfs_d_iput,
	31	};
	32
	33	/*
	34	* Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
	35	*/
b592fcfe	36	static struct sysfs_dirent * __sysfs_new_dirent(void * element)
1da177e4 LT	37	{
	38	struct sysfs_dirent * sd;
	39
c3762229	40	sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
1da177e4 LT	41	if (!sd)
	42	return NULL;
	43
1da177e4	44	atomic_set(&sd->s_count, 1);
eea3f891	45	atomic_set(&sd->s_event, 1);
1da177e4	46	INIT_LIST_HEAD(&sd->s_children);
b592fcfe	47	INIT_LIST_HEAD(&sd->s_sibling);
1da177e4 LT	48	sd->s_element = element;
	49
	50	return sd;
	51	}
	52
b592fcfe EB	53	static void __sysfs_list_dirent(struct sysfs_dirent *parent_sd,
	54	struct sysfs_dirent *sd)
	55	{
	56	if (sd)
	57	list_add(&sd->s_sibling, &parent_sd->s_children);
	58	}
	59
	60	static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent *parent_sd,
	61	void * element)
	62	{
	63	struct sysfs_dirent *sd;
	64	sd = __sysfs_new_dirent(element);
	65	__sysfs_list_dirent(parent_sd, sd);
	66	return sd;
	67	}
	68
a580290c	69	/*
c516865c MS	70	*
	71	* Return -EEXIST if there is already a sysfs element with the same name for
	72	* the same parent.
	73	*
	74	* called with parent inode's i_mutex held
	75	*/
	76	int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
	77	const unsigned char *new)
	78	{
	79	struct sysfs_dirent * sd;
	80
	81	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
	82	if (sd->s_element) {
	83	const unsigned char *existing = sysfs_get_name(sd);
	84	if (strcmp(existing, new))
	85	continue;
	86	else
	87	return -EEXIST;
	88	}
	89	}
	90
	91	return 0;
	92	}
	93
	94
b592fcfe EB	95	static struct sysfs_dirent *
b592fcfe EB	96	__sysfs_make_dirent(struct dentry dentry, void element, mode_t mode, int type)
1da177e4 LT	97	{
	98	struct sysfs_dirent * sd;
	99
b592fcfe	100	sd = __sysfs_new_dirent(element);
1da177e4	101	if (!sd)
b592fcfe	102	goto out;
1da177e4 LT	103
	104	sd->s_mode = mode;
	105	sd->s_type = type;
	106	sd->s_dentry = dentry;
	107	if (dentry) {
	108	dentry->d_fsdata = sysfs_get(sd);
	109	dentry->d_op = &sysfs_dentry_ops;
	110	}
	111
b592fcfe EB	112	out:
	113	return sd;
	114	}
	115
	116	int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
	117	void * element, umode_t mode, int type)
	118	{
	119	struct sysfs_dirent *sd;
	120
	121	sd = __sysfs_make_dirent(dentry, element, mode, type);
	122	__sysfs_list_dirent(parent_sd, sd);
	123
	124	return sd ? 0 : -ENOMEM;
1da177e4 LT	125	}
	126
	127	static int init_dir(struct inode * inode)
	128	{
	129	inode->i_op = &sysfs_dir_inode_operations;
	130	inode->i_fop = &sysfs_dir_operations;
	131
	132	/* directory inodes start off with i_nlink == 2 (for "." entry) */
d8c76e6f	133	inc_nlink(inode);
1da177e4 LT	134	return 0;
	135	}
	136
	137	static int init_file(struct inode * inode)
	138	{
	139	inode->i_size = PAGE_SIZE;
	140	inode->i_fop = &sysfs_file_operations;
	141	return 0;
	142	}
	143
	144	static int init_symlink(struct inode * inode)
	145	{
	146	inode->i_op = &sysfs_symlink_inode_operations;
	147	return 0;
	148	}
	149
	150	static int create_dir(struct kobject * k, struct dentry * p,
	151	const char * n, struct dentry ** d)
	152	{
	153	int error;
	154	umode_t mode = S_IFDIR\| S_IRWXU \| S_IRUGO \| S_IXUGO;
	155
1b1dcc1b	156	mutex_lock(&p->d_inode->i_mutex);
5f45f1a7	157	*d = lookup_one_len(n, p, strlen(n));
1da177e4	158	if (!IS_ERR(*d)) {
c516865c MS	159	if (sysfs_dirent_exist(p->d_fsdata, n))
	160	error = -EEXIST;
	161	else
	162	error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
	163	SYSFS_DIR);
1da177e4	164	if (!error) {
6fa5c828	165	error = sysfs_create(*d, mode, init_dir);
1da177e4	166	if (!error) {
d8c76e6f	167	inc_nlink(p->d_inode);
1da177e4 LT	168	(*d)->d_op = &sysfs_dentry_ops;
	169	d_rehash(*d);
	170	}
	171	}
6fa5c828	172	if (error && (error != -EEXIST)) {
e80a5dea SR	173	struct sysfs_dirent sd = (d)->d_fsdata;
	174	if (sd) {
	175	list_del_init(&sd->s_sibling);
	176	sysfs_put(sd);
	177	}
1da177e4	178	d_drop(*d);
6fa5c828	179	}
1da177e4 LT	180	dput(*d);
	181	} else
	182	error = PTR_ERR(*d);
1b1dcc1b	183	mutex_unlock(&p->d_inode->i_mutex);
1da177e4 LT	184	return error;
	185	}
	186
	187
	188	int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
	189	{
	190	return create_dir(k,k->dentry,n,d);
	191	}
	192
	193	/**
	194	* sysfs_create_dir - create a directory for an object.
1da177e4	195	* @kobj: object we're creating directory for.
b592fcfe	196	* @shadow_parent: parent parent object.
1da177e4 LT	197	*/
1da177e4 LT	198
b592fcfe	199	int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent)
1da177e4 LT	200	{
	201	struct dentry * dentry = NULL;
	202	struct dentry * parent;
	203	int error = 0;
	204
	205	BUG_ON(!kobj);
	206
b592fcfe EB	207	if (shadow_parent)
	208	parent = shadow_parent;
	209	else if (kobj->parent)
1da177e4 LT	210	parent = kobj->parent->dentry;
	211	else if (sysfs_mount && sysfs_mount->mnt_sb)
	212	parent = sysfs_mount->mnt_sb->s_root;
	213	else
	214	return -EFAULT;
	215
	216	error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
	217	if (!error)
	218	kobj->dentry = dentry;
	219	return error;
	220	}
	221
	222	/* attaches attribute's sysfs_dirent to the dentry corresponding to the
	223	* attribute file
	224	*/
	225	static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
	226	{
	227	struct attribute * attr = NULL;
	228	struct bin_attribute * bin_attr = NULL;
	229	int (* init) (struct inode *) = NULL;
	230	int error = 0;
	231
	232	if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
	233	bin_attr = sd->s_element;
	234	attr = &bin_attr->attr;
	235	} else {
	236	attr = sd->s_element;
	237	init = init_file;
	238	}
	239
6fa5c828 MS	240	dentry->d_fsdata = sysfs_get(sd);
6fa5c828 MS	241	sd->s_dentry = dentry;
1da177e4	242	error = sysfs_create(dentry, (attr->mode & S_IALLUGO) \| S_IFREG, init);
6fa5c828 MS	243	if (error) {
6fa5c828 MS	244	sysfs_put(sd);
1da177e4	245	return error;
6fa5c828	246	}
1da177e4 LT	247
	248	if (bin_attr) {
	249	dentry->d_inode->i_size = bin_attr->size;
	250	dentry->d_inode->i_fop = &bin_fops;
	251	}
	252	dentry->d_op = &sysfs_dentry_ops;
1da177e4 LT	253	d_rehash(dentry);
	254
	255	return 0;
	256	}
	257
	258	static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
	259	{
	260	int err = 0;
	261
6fa5c828 MS	262	dentry->d_fsdata = sysfs_get(sd);
6fa5c828 MS	263	sd->s_dentry = dentry;
1da177e4 LT	264	err = sysfs_create(dentry, S_IFLNK\|S_IRWXUGO, init_symlink);
	265	if (!err) {
	266	dentry->d_op = &sysfs_dentry_ops;
1da177e4	267	d_rehash(dentry);
6fa5c828 MS	268	} else
	269	sysfs_put(sd);
	270
1da177e4 LT	271	return err;
	272	}
	273
	274	static struct dentry * sysfs_lookup(struct inode dir, struct dentry dentry,
	275	struct nameidata *nd)
	276	{
	277	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
	278	struct sysfs_dirent * sd;
	279	int err = 0;
	280
	281	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
	282	if (sd->s_type & SYSFS_NOT_PINNED) {
	283	const unsigned char * name = sysfs_get_name(sd);
	284
	285	if (strcmp(name, dentry->d_name.name))
	286	continue;
	287
	288	if (sd->s_type & SYSFS_KOBJ_LINK)
	289	err = sysfs_attach_link(sd, dentry);
	290	else
	291	err = sysfs_attach_attr(sd, dentry);
	292	break;
	293	}
	294	}
	295
	296	return ERR_PTR(err);
	297	}
	298
c5ef1c42	299	const struct inode_operations sysfs_dir_inode_operations = {
1da177e4	300	.lookup = sysfs_lookup,
988d186d	301	.setattr = sysfs_setattr,
1da177e4 LT	302	};
	303
	304	static void remove_dir(struct dentry * d)
	305	{
	306	struct dentry * parent = dget(d->d_parent);
	307	struct sysfs_dirent * sd;
	308
1b1dcc1b	309	mutex_lock(&parent->d_inode->i_mutex);
1da177e4 LT	310	d_delete(d);
	311	sd = d->d_fsdata;
	312	list_del_init(&sd->s_sibling);
	313	sysfs_put(sd);
	314	if (d->d_inode)
	315	simple_rmdir(parent->d_inode,d);
	316
	317	pr_debug(" o %s removing done (%d)\n",d->d_name.name,
	318	atomic_read(&d->d_count));
	319
1b1dcc1b	320	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	321	dput(parent);
	322	}
	323
	324	void sysfs_remove_subdir(struct dentry * d)
	325	{
	326	remove_dir(d);
	327	}
	328
	329
b592fcfe	330	static void __sysfs_remove_dir(struct dentry *dentry)
1da177e4	331	{
1da177e4 LT	332	struct sysfs_dirent * parent_sd;
	333	struct sysfs_dirent * sd, * tmp;
	334
b592fcfe	335	dget(dentry);
1da177e4 LT	336	if (!dentry)
	337	return;
	338
	339	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
1b1dcc1b	340	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4 LT	341	parent_sd = dentry->d_fsdata;
	342	list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
	343	if (!sd->s_element \|\| !(sd->s_type & SYSFS_NOT_PINNED))
	344	continue;
	345	list_del_init(&sd->s_sibling);
	346	sysfs_drop_dentry(sd, dentry);
	347	sysfs_put(sd);
	348	}
1b1dcc1b	349	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	350
	351	remove_dir(dentry);
	352	/**
	353	* Drop reference from dget() on entrance.
	354	*/
	355	dput(dentry);
b592fcfe EB	356	}
	357
	358	/**
	359	* sysfs_remove_dir - remove an object's directory.
	360	* @kobj: object.
	361	*
	362	* The only thing special about this is that we remove any files in
	363	* the directory before we remove the directory, and we've inlined
	364	* what used to be sysfs_rmdir() below, instead of calling separately.
	365	*/
	366
	367	void sysfs_remove_dir(struct kobject * kobj)
	368	{
	369	__sysfs_remove_dir(kobj->dentry);
641e6f30	370	kobj->dentry = NULL;
1da177e4 LT	371	}
1da177e4 LT	372
b592fcfe EB	373	int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent,
b592fcfe EB	374	const char *new_name)
1da177e4 LT	375	{
1da177e4 LT	376	int error = 0;
b592fcfe	377	struct dentry * new_dentry;
1da177e4	378
b592fcfe EB	379	if (!new_parent)
b592fcfe EB	380	return -EFAULT;
1da177e4 LT	381
1da177e4 LT	382	down_write(&sysfs_rename_sem);
b592fcfe	383	mutex_lock(&new_parent->d_inode->i_mutex);
1da177e4	384
b592fcfe	385	new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
1da177e4	386	if (!IS_ERR(new_dentry)) {
b592fcfe EB	387	/* By allowing two different directories with the
	388	* same d_parent we allow this routine to move
	389	* between different shadows of the same directory
	390	*/
	391	if (kobj->dentry->d_parent->d_inode != new_parent->d_inode)
	392	return -EINVAL;
	393	else if (new_dentry->d_parent->d_inode != new_parent->d_inode)
	394	error = -EINVAL;
	395	else if (new_dentry == kobj->dentry)
	396	error = -EINVAL;
	397	else if (!new_dentry->d_inode) {
1da177e4 LT	398	error = kobject_set_name(kobj, "%s", new_name);
1da177e4 LT	399	if (!error) {
b592fcfe EB	400	struct sysfs_dirent sd, parent_sd;
b592fcfe EB	401
1da177e4 LT	402	d_add(new_dentry, NULL);
1da177e4 LT	403	d_move(kobj->dentry, new_dentry);
b592fcfe EB	404
	405	sd = kobj->dentry->d_fsdata;
	406	parent_sd = new_parent->d_fsdata;
	407
	408	list_del_init(&sd->s_sibling);
	409	list_add(&sd->s_sibling, &parent_sd->s_children);
1da177e4 LT	410	}
	411	else
	412	d_drop(new_dentry);
	413	} else
	414	error = -EEXIST;
	415	dput(new_dentry);
	416	}
b592fcfe	417	mutex_unlock(&new_parent->d_inode->i_mutex);
1da177e4 LT	418	up_write(&sysfs_rename_sem);
	419
	420	return error;
	421	}
	422
8a82472f CH	423	int sysfs_move_dir(struct kobject kobj, struct kobject new_parent)
	424	{
	425	struct dentry old_parent_dentry, new_parent_dentry, *new_dentry;
	426	struct sysfs_dirent new_parent_sd, sd;
	427	int error;
	428
8a82472f CH	429	old_parent_dentry = kobj->parent ?
8a82472f CH	430	kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;
c744aeae CH	431	new_parent_dentry = new_parent ?
c744aeae CH	432	new_parent->dentry : sysfs_mount->mnt_sb->s_root;
8a82472f	433
0de1517e ML	434	if (old_parent_dentry->d_inode == new_parent_dentry->d_inode)
0de1517e ML	435	return 0; /* nothing to move */
8a82472f CH	436	again:
	437	mutex_lock(&old_parent_dentry->d_inode->i_mutex);
	438	if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) {
	439	mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
	440	goto again;
	441	}
	442
	443	new_parent_sd = new_parent_dentry->d_fsdata;
	444	sd = kobj->dentry->d_fsdata;
	445
	446	new_dentry = lookup_one_len(kobj->name, new_parent_dentry,
	447	strlen(kobj->name));
	448	if (IS_ERR(new_dentry)) {
	449	error = PTR_ERR(new_dentry);
	450	goto out;
	451	} else
	452	error = 0;
	453	d_add(new_dentry, NULL);
	454	d_move(kobj->dentry, new_dentry);
	455	dput(new_dentry);
	456
	457	/* Remove from old parent's list and insert into new parent's list. */
	458	list_del_init(&sd->s_sibling);
	459	list_add(&sd->s_sibling, &new_parent_sd->s_children);
	460
	461	out:
	462	mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
	463	mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
	464
	465	return error;
	466	}
	467
1da177e4 LT	468	static int sysfs_dir_open(struct inode inode, struct file file)
1da177e4 LT	469	{
f427f5d5	470	struct dentry * dentry = file->f_path.dentry;
1da177e4 LT	471	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
1da177e4 LT	472
1b1dcc1b	473	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4	474	file->private_data = sysfs_new_dirent(parent_sd, NULL);
1b1dcc1b	475	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	476
	477	return file->private_data ? 0 : -ENOMEM;
	478
	479	}
	480
	481	static int sysfs_dir_close(struct inode inode, struct file file)
	482	{
f427f5d5	483	struct dentry * dentry = file->f_path.dentry;
1da177e4 LT	484	struct sysfs_dirent * cursor = file->private_data;
1da177e4 LT	485
1b1dcc1b	486	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4	487	list_del_init(&cursor->s_sibling);
1b1dcc1b	488	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	489
	490	release_sysfs_dirent(cursor);
	491
	492	return 0;
	493	}
	494
	495	/* Relationship between s_mode and the DT_xxx types */
	496	static inline unsigned char dt_type(struct sysfs_dirent *sd)
	497	{
	498	return (sd->s_mode >> 12) & 15;
	499	}
	500
	501	static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
	502	{
f427f5d5	503	struct dentry *dentry = filp->f_path.dentry;
1da177e4 LT	504	struct sysfs_dirent * parent_sd = dentry->d_fsdata;
	505	struct sysfs_dirent *cursor = filp->private_data;
	506	struct list_head p, q = &cursor->s_sibling;
	507	ino_t ino;
	508	int i = filp->f_pos;
	509
	510	switch (i) {
	511	case 0:
	512	ino = dentry->d_inode->i_ino;
	513	if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
	514	break;
	515	filp->f_pos++;
	516	i++;
	517	/* fallthrough */
	518	case 1:
	519	ino = parent_ino(dentry);
	520	if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
	521	break;
	522	filp->f_pos++;
	523	i++;
	524	/* fallthrough */
	525	default:
1bfba4e8 AM	526	if (filp->f_pos == 2)
	527	list_move(q, &parent_sd->s_children);
	528
1da177e4 LT	529	for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
	530	struct sysfs_dirent *next;
	531	const char * name;
	532	int len;
	533
	534	next = list_entry(p, struct sysfs_dirent,
	535	s_sibling);
	536	if (!next->s_element)
	537	continue;
	538
	539	name = sysfs_get_name(next);
	540	len = strlen(name);
	541	if (next->s_dentry)
	542	ino = next->s_dentry->d_inode->i_ino;
	543	else
	544	ino = iunique(sysfs_sb, 2);
	545
	546	if (filldir(dirent, name, len, filp->f_pos, ino,
	547	dt_type(next)) < 0)
	548	return 0;
	549
1bfba4e8	550	list_move(q, p);
1da177e4 LT	551	p = q;
	552	filp->f_pos++;
	553	}
	554	}
	555	return 0;
	556	}
	557
	558	static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
	559	{
f427f5d5	560	struct dentry * dentry = file->f_path.dentry;
1da177e4	561
1b1dcc1b	562	mutex_lock(&dentry->d_inode->i_mutex);
1da177e4 LT	563	switch (origin) {
	564	case 1:
	565	offset += file->f_pos;
	566	case 0:
	567	if (offset >= 0)
	568	break;
	569	default:
f427f5d5	570	mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
1da177e4 LT	571	return -EINVAL;
	572	}
	573	if (offset != file->f_pos) {
	574	file->f_pos = offset;
	575	if (file->f_pos >= 2) {
	576	struct sysfs_dirent *sd = dentry->d_fsdata;
	577	struct sysfs_dirent *cursor = file->private_data;
	578	struct list_head *p;
	579	loff_t n = file->f_pos - 2;
	580
	581	list_del(&cursor->s_sibling);
	582	p = sd->s_children.next;
	583	while (n && p != &sd->s_children) {
	584	struct sysfs_dirent *next;
	585	next = list_entry(p, struct sysfs_dirent,
	586	s_sibling);
	587	if (next->s_element)
	588	n--;
	589	p = p->next;
	590	}
	591	list_add_tail(&cursor->s_sibling, p);
	592	}
	593	}
1b1dcc1b	594	mutex_unlock(&dentry->d_inode->i_mutex);
1da177e4 LT	595	return offset;
	596	}
	597
b592fcfe EB	598
	599	/**
	600	* sysfs_make_shadowed_dir - Setup so a directory can be shadowed
	601	* @kobj: object we're creating shadow of.
	602	*/
	603
	604	int sysfs_make_shadowed_dir(struct kobject *kobj,
	605	void * (follow_link)(struct dentry , struct nameidata *))
	606	{
	607	struct inode *inode;
	608	struct inode_operations *i_op;
	609
	610	inode = kobj->dentry->d_inode;
	611	if (inode->i_op != &sysfs_dir_inode_operations)
	612	return -EINVAL;
	613
	614	i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
	615	if (!i_op)
	616	return -ENOMEM;
	617
	618	memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
	619	i_op->follow_link = follow_link;
	620
	621	/* Locking of inode->i_op?
	622	* Since setting i_op is a single word write and they
	623	* are atomic we should be ok here.
	624	*/
	625	inode->i_op = i_op;
	626	return 0;
	627	}
	628
	629	/**
	630	* sysfs_create_shadow_dir - create a shadow directory for an object.
	631	* @kobj: object we're creating directory for.
	632	*
	633	* sysfs_make_shadowed_dir must already have been called on this
	634	* directory.
	635	*/
	636
	637	struct dentry sysfs_create_shadow_dir(struct kobject kobj)
	638	{
	639	struct sysfs_dirent *sd;
	640	struct dentry parent, dir, *shadow;
	641	struct inode *inode;
	642
	643	dir = kobj->dentry;
	644	inode = dir->d_inode;
	645	parent = dir->d_parent;
	646	shadow = ERR_PTR(-EINVAL);
	647	if (!sysfs_is_shadowed_inode(inode))
	648	goto out;
	649
	650	shadow = d_alloc(parent, &dir->d_name);
	651	if (!shadow)
	652	goto nomem;
	653
	654	sd = __sysfs_make_dirent(shadow, kobj, inode->i_mode, SYSFS_DIR);
	655	if (!sd)
	656	goto nomem;
	657
	658	d_instantiate(shadow, igrab(inode));
	659	inc_nlink(inode);
	660	inc_nlink(parent->d_inode);
	661	shadow->d_op = &sysfs_dentry_ops;
662
663	dget(shadow); /* Extra count - pin the dentry in core */
664
665	out:
666	return shadow;
667	nomem:
668	dput(shadow);
669	shadow = ERR_PTR(-ENOMEM);
670	goto out;
671	}
672
673	/**
674	* sysfs_remove_shadow_dir - remove an object's directory.
675	* @shadow: dentry of shadow directory
676	*
677	* The only thing special about this is that we remove any files in
678	* the directory before we remove the directory, and we've inlined
679	* what used to be sysfs_rmdir() below, instead of calling separately.
680	*/
681
682	void sysfs_remove_shadow_dir(struct dentry *shadow)
683	{
684	__sysfs_remove_dir(shadow);
685	}
686
4b6f5d20	687	const struct file_operations sysfs_dir_operations = {
1da177e4 LT	688	.open = sysfs_dir_open,
	689	.release = sysfs_dir_close,
	690	.llseek = sysfs_dir_lseek,
	691	.read = generic_read_dir,
	692	.readdir = sysfs_readdir,
	693	};