From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:33400 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932172AbcILPHZ (ORCPT ); Mon, 12 Sep 2016 11:07:25 -0400 From: Amir Goldstein To: Miklos Szeredi , Dave Chinner , linux-unionfs@vger.kernel.org Cc: Christoph Hellwig , linux-xfs@vger.kernel.org, "Darrick J . Wong" , linux-fsdevel@vger.kernel.org Subject: [PATCH v2 2/4] ovl: use vfs_clone_file_range() for copy up if possible Date: Mon, 12 Sep 2016 18:06:41 +0300 Message-Id: <1473692803-11964-3-git-send-email-amir73il@gmail.com> In-Reply-To: <1473692803-11964-1-git-send-email-amir73il@gmail.com> References: <1473348594-31425-1-git-send-email-amir73il@gmail.com> <1473692803-11964-1-git-send-email-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: When copying up within the same fs, try to use vfs_clone_file_range(). This is very efficient when lower and upper are on the same fs with file reflink support. If vfs_clone_file_range() fails because lower and upper are not on the same fs or if fs has no reflink support, copy up falls back to the regular data copy code. Tested correct behavior when lower and upper are on: 1. same ext4 (copy) 2. same xfs + reflink patches + mkfs.xfs (copy) 3. same xfs + reflink patches + mkfs.xfs -m reflink=1 (clone) 4. different xfs + reflink patches + mkfs.xfs -m reflink=1 (copy) For comparison, on my laptop, xfstest overlay/001 (copy up of large sparse files) takes less than 1 second in the xfs reflink setup vs. 25 seconds on the rest of the setups. Signed-off-by: Amir Goldstein --- fs/overlayfs/copy_up.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 43fdc27..e432d7e 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -136,6 +136,16 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) goto out_fput; } + /* + * Try to use clone_file_range to clone up within the same fs. + * On failure to clone entire file, fallback to copy loop. + */ + error = vfs_clone_file_range(old_file, 0, new_file, 0, len); + if (error == -EXDEV || error == -EOPNOTSUPP) + error = 0; + else + len = 0; + /* FIXME: copy up sparse files efficiently */ while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; -- 2.7.4