fix setattr error handling in sysfs, configfs

sysfs and configfs setattr functions have error cases after the generic inode's
attributes have been changed. Fix consistency by changing the generic inode
attributes only when it is guaranteed to succeed.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/configfs/inode.c

@@ -72,10 +72,6 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
 	if (!sd)
 		return -EINVAL;
 
-	error = simple_setattr(dentry, iattr);
-	if (error)
-		return error;
-
 	sd_iattr = sd->s_iattr;
 	if (!sd_iattr) {
 		/* setting attributes for the first time, allocate now */
@@ -89,9 +85,12 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
 		sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
 		sd->s_iattr = sd_iattr;
 	}
-
 	/* attributes were changed atleast once in past */
 
+	error = simple_setattr(dentry, iattr);
+	if (error)
+		return error;
+
 	if (ia_valid & ATTR_UID)
 		sd_iattr->ia_uid = iattr->ia_uid;
 	if (ia_valid & ATTR_GID)

fs/sysfs/inode.c

@@ -117,11 +117,13 @@ int sysfs_setattr(struct dentry *dentry, struct iattr *iattr)
 	if (error)
 		goto out;
 
+	error = sysfs_sd_setattr(sd, iattr);
+	if (error)
+		goto out;
+
 	/* this ignores size changes */
 	generic_setattr(inode, iattr);
 
-	error = sysfs_sd_setattr(sd, iattr);
-
 out:
 	mutex_unlock(&sysfs_mutex);
 	return error;