From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: [PATCH 07/26] vfs: skip zero-length dedupe requests From: "Darrick J. Wong" 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 Date: Mon, 15 Oct 2018 20:10:44 -0700 Message-ID: <153965944451.1256.13419242995682379278.stgit@magnolia> In-Reply-To: <153965939489.1256.7400115244528045860.stgit@magnolia> References: <153965939489.1256.7400115244528045860.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: 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: