selinux: Clean up initialization of isec->sclass

Now that isec->initialized == LABEL_INITIALIZED implies that
isec->sclass is valid, skip such inodes immediately in
inode_doinit_with_dentry.

For the remaining inodes, initialize isec->sclass at the beginning of
inode_doinit_with_dentry to simplify the code.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/hooks.c

@@ -1390,12 +1390,15 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 	int rc = 0;
 
 	if (isec->initialized == LABEL_INITIALIZED)
-		goto out;
+		return 0;
 
 	mutex_lock(&isec->lock);
 	if (isec->initialized == LABEL_INITIALIZED)
 		goto out_unlock;
 
+	if (isec->sclass == SECCLASS_FILE)
+		isec->sclass = inode_mode_to_security_class(inode->i_mode);
+
 	sbsec = inode->i_sb->s_security;
 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
 		/* Defer initialization until selinux_complete_init,
@@ -1513,7 +1516,6 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 		isec->sid = sbsec->sid;
 
 		/* Try to obtain a transition SID. */
-		isec->sclass = inode_mode_to_security_class(inode->i_mode);
 		rc = security_transition_sid(isec->task_sid, sbsec->sid,
 					     isec->sclass, NULL, &sid);
 		if (rc)
@@ -1549,7 +1551,6 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			 */
 			if (!dentry)
 				goto out_unlock;
-			isec->sclass = inode_mode_to_security_class(inode->i_mode);
 			rc = selinux_genfs_get_sid(dentry, isec->sclass,
 						   sbsec->flags, &sid);
 			dput(dentry);
@@ -1564,9 +1565,6 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 
 out_unlock:
 	mutex_unlock(&isec->lock);
-out:
-	if (isec->sclass == SECCLASS_FILE)
-		isec->sclass = inode_mode_to_security_class(inode->i_mode);
 	return rc;
 }