From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 41F086B026F for ; Tue, 9 Oct 2018 20:11:37 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id i76-v6so3227242pfk.14 for ; Tue, 09 Oct 2018 17:11:37 -0700 (PDT) Received: from userp2130.oracle.com (userp2130.oracle.com. [156.151.31.86]) by mx.google.com with ESMTPS id x186-v6si24643467pfx.19.2018.10.09.17.11.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Oct 2018 17:11:36 -0700 (PDT) Subject: [PATCH 07/25] vfs: skip zero-length dedupe requests From: "Darrick J. Wong" Date: Tue, 09 Oct 2018 17:11:27 -0700 Message-ID: <153913028716.32295.15849395030883190383.stgit@magnolia> In-Reply-To: <153913023835.32295.13962696655740190941.stgit@magnolia> References: <153913023835.32295.13962696655740190941.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: david@fromorbit.com, darrick.wong@oracle.com Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig , ocfs2-devel@oss.oracle.com From: Darrick J. Wong Don't bother calling the filesystem for a zero-length dedupe request; we can return zero and exit. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/read_write.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/read_write.c b/fs/read_write.c index f7b728d4972f..3ff90b3315fb 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1975,6 +1975,11 @@ int vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, if (!dst_file->f_op->dedupe_file_range) goto out_drop_write; + if (len == 0) { + ret = 0; + goto out_drop_write; + } + ret = dst_file->f_op->dedupe_file_range(src_file, src_pos, dst_file, dst_pos, len); out_drop_write: