From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-f197.google.com (mail-yb1-f197.google.com [209.85.219.197]) by kanga.kvack.org (Postfix) with ESMTP id 044B46B0269 for ; Sun, 21 Oct 2018 12:15:58 -0400 (EDT) Received: by mail-yb1-f197.google.com with SMTP id z8-v6so22924584ybo.17 for ; Sun, 21 Oct 2018 09:15:57 -0700 (PDT) Received: from aserp2120.oracle.com (aserp2120.oracle.com. [141.146.126.78]) by mx.google.com with ESMTPS id j66-v6si13879206ywe.442.2018.10.21.09.15.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 21 Oct 2018 09:15:57 -0700 (PDT) Subject: [PATCH 06/28] vfs: skip zero-length dedupe requests From: "Darrick J. Wong" Date: Sun, 21 Oct 2018 09:15:44 -0700 Message-ID: <154013854491.29026.1645091969567859095.stgit@magnolia> In-Reply-To: <154013850285.29026.16168387526580596209.stgit@magnolia> References: <154013850285.29026.16168387526580596209.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, Amir Goldstein , 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 Reviewed-by: Amir Goldstein --- fs/read_write.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/read_write.c b/fs/read_write.c index 0f0a6efdd502..f5395d8da741 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -2009,6 +2009,11 @@ 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: