diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index fe3119a71adacb65172cdc6be3c390f55e234679..2845425077e857c85ac7413a9613786d0dd0ac25 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -2875,8 +2875,10 @@ static ssize_t ext3_quota_write(struct super_block *sb, int type,
 		blk++;
 	}
 out:
-	if (len == towrite)
+	if (len == towrite) {
+		mutex_unlock(&inode->i_mutex);
 		return err;
+	}
 	if (inode->i_size < off+len-towrite) {
 		i_size_write(inode, off+len-towrite);
 		EXT3_I(inode)->i_disksize = inode->i_size;