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Commit 06fc0d66 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
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sysfs: In sysfs_chmod_file lazily propagate the mode change. 



Now that sysfs_getattr and sysfs_permission refresh the vfs
inode there is no need to immediatly push the mode change
into the vfs cache.  Reducing the amount of work needed and
simplifying the locking.

Acked-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e61ab4ae

fs/sysfs/file.c

+8 −23
Original line number Diff line number Diff line
@@ -579,38 +579,23 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_group); 
 */

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

{

	struct sysfs_dirent *victim_sd = NULL;

	struct dentry *victim = NULL;

	struct inode * inode;

	struct sysfs_dirent *sd;

	struct iattr newattrs;

	int rc;



	rc = -ENOENT;

	victim_sd = sysfs_get_dirent(kobj->sd, attr->name);

	if (!victim_sd)

		goto out;

	mutex_lock(&sysfs_mutex);



	mutex_lock(&sysfs_rename_mutex);

	victim = sysfs_get_dentry(victim_sd);

	mutex_unlock(&sysfs_rename_mutex);

	if (IS_ERR(victim)) {

		rc = PTR_ERR(victim);

		victim = NULL;

	rc = -ENOENT;

	sd = sysfs_find_dirent(kobj->sd, attr->name);

	if (!sd)

		goto out;

	}



	inode = victim->d_inode;



	mutex_lock(&inode->i_mutex);



	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);

	newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO);

	newattrs.ia_valid = ATTR_MODE;

	rc = sysfs_setattr(victim, &newattrs);

	rc = sysfs_sd_setattr(sd, &newattrs);



	mutex_unlock(&inode->i_mutex);

 out:

	dput(victim);

	sysfs_put(victim_sd);

	mutex_unlock(&sysfs_mutex);

	return rc;

}

EXPORT_SYMBOL_GPL(sysfs_chmod_file);