Commit 31e5abe9 authored by Kay Sievers's avatar Kay Sievers Committed by Greg KH
Browse files

[PATCH] sysfs: add sysfs_chmod_file() 



sysfs: allow changing the permissions for already created attributes

Signed-off-by: default avatarKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 6897089c

fs/sysfs/file.c

+35 −0
Original line number Diff line number Diff line
@@ -427,6 +427,41 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) 
}





/**

 * sysfs_chmod_file - update the modified mode value on an object attribute.

 * @kobj: object we're acting for.

 * @attr: attribute descriptor.

 * @mode: file permissions.

 *

 */

int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)

{

	struct dentry *dir = kobj->dentry;

	struct dentry *victim;

	struct sysfs_dirent *sd;

	umode_t umode = (mode & S_IALLUGO) | S_IFREG;

	int res = -ENOENT;



	down(&dir->d_inode->i_sem);

	victim = sysfs_get_dentry(dir, attr->name);

	if (!IS_ERR(victim)) {

		if (victim->d_inode &&

		    (victim->d_parent->d_inode == dir->d_inode)) {

			sd = victim->d_fsdata;

			attr->mode = mode;

			sd->s_mode = umode;

			victim->d_inode->i_mode = umode;

			dput(victim);

			res = 0;

		}

	}

	up(&dir->d_inode->i_sem);



	return res;

}

EXPORT_SYMBOL_GPL(sysfs_chmod_file);





/**

 *	sysfs_remove_file - remove an object attribute.

 *	@kobj:	object we're acting for.

include/linux/sysfs.h

+7 −0
Original line number Diff line number Diff line
@@ -99,6 +99,9 @@ sysfs_create_file(struct kobject *, const struct attribute *); 
extern int

sysfs_update_file(struct kobject *, const struct attribute *);



extern int

sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode);



extern void

sysfs_remove_file(struct kobject *, const struct attribute *);
@@ -140,6 +143,10 @@ static inline int sysfs_update_file(struct kobject * k, const struct attribute * 
{

	return 0;

}

static inline int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)

{

	return 0;

}



static inline void sysfs_remove_file(struct kobject * k, const struct attribute * a)

{