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Commit 9918f9a4 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
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sysfs: Rewrite rename in terms of sysfs dirents 



This patch rewrites sysfs_rename_dir to perform it's checks
as much as possible on the underlying sysfs_dirents instead
of the contents of the dcache.  It turns out that this version
is a little simpler, and a little more like the rest of
the sysfs directory modification code.

tj: fixed double locking of sysfs_mutex

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 5a26b79c

fs/sysfs/dir.c

+16 −22
Original line number Diff line number Diff line
@@ -770,7 +770,7 @@ void sysfs_remove_dir(struct kobject * kobj) 


int sysfs_rename_dir(struct kobject * kobj, const char *new_name)

{

	struct sysfs_dirent *sd;

	struct sysfs_dirent *sd = kobj->sd;

	struct dentry *parent = NULL;

	struct dentry *old_dentry = NULL, *new_dentry = NULL;

	const char *dup_name = NULL;
@@ -778,63 +778,57 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name) 


	mutex_lock(&sysfs_rename_mutex);



	error = 0;

	if (strcmp(sd->s_name, new_name) == 0)

		goto out;	/* nothing to rename */



	/* get the original dentry */

	sd = kobj->sd;

	old_dentry = sysfs_get_dentry(sd);

	if (IS_ERR(old_dentry)) {

		error = PTR_ERR(old_dentry);

		goto out_dput;

		goto out;

	}



	parent = old_dentry->d_parent;



	/* lock parent and get dentry for new name */

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

	mutex_lock(&sysfs_mutex);



	new_dentry = lookup_one_len(new_name, parent, strlen(new_name));

	if (IS_ERR(new_dentry)) {

		error = PTR_ERR(new_dentry);

		goto out_unlock;

	}



	error = -EINVAL;

	if (old_dentry == new_dentry)

	error = -EEXIST;

	if (sysfs_find_dirent(sd->s_parent, new_name))

		goto out_unlock;



	error = -EEXIST;

	if (new_dentry->d_inode)

	error = -ENOMEM;

	new_dentry = d_alloc_name(parent, new_name);

	if (!new_dentry)

		goto out_unlock;



	/* rename kobject and sysfs_dirent */

	error = -ENOMEM;

	new_name = dup_name = kstrdup(new_name, GFP_KERNEL);

	if (!new_name)

		goto out_drop;

		goto out_unlock;



	error = kobject_set_name(kobj, "%s", new_name);

	if (error)

		goto out_drop;

		goto out_unlock;



	mutex_lock(&sysfs_mutex);

	dup_name = sd->s_name;

	sd->s_name = new_name;

	mutex_unlock(&sysfs_mutex);



	/* rename */

	d_add(new_dentry, NULL);

	d_move(old_dentry, new_dentry);



	error = 0;

	goto out_unlock;



 out_drop:

	d_drop(new_dentry);

 out_unlock:

	mutex_unlock(&sysfs_mutex);

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

 out_dput:

	kfree(dup_name);

	dput(old_dentry);

	dput(new_dentry);

 out:

	mutex_unlock(&sysfs_rename_mutex);

	return error;

}