From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f68.google.com ([74.125.82.68]:36331 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757539AbcIHPbF (ORCPT ); Thu, 8 Sep 2016 11:31:05 -0400 From: Amir Goldstein Subject: [PATCH] ovl: use copy_file_range for copy up if possible Date: Thu, 8 Sep 2016 18:29:54 +0300 Message-Id: <1473348594-31425-1-git-send-email-amir73il@gmail.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Miklos Szeredi , "Darrick J . Wong" Cc: linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Amir Goldstein When copying up within the same fs, try to use f_op->copy_file_range(). This becomes very efficient when lower and upper are on the same fs with file reflink support. 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) Verified that all the overlay xfstests pass in the 'same xfs+reflink' setup. 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 | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 43fdc27..400567b 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -121,6 +121,7 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) struct file *new_file; loff_t old_pos = 0; loff_t new_pos = 0; + int try_copy_file = 0; int error = 0; if (len == 0) @@ -136,6 +137,13 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) goto out_fput; } + /* + * When copying up within the same fs, try to use fs's copy_file_range + */ + if (file_inode(old_file)->i_sb == file_inode(new_file)->i_sb) { + try_copy_file = (new_file->f_op->copy_file_range != NULL); + } + /* FIXME: copy up sparse files efficiently */ while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; @@ -149,9 +157,23 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) break; } - bytes = do_splice_direct(old_file, &old_pos, - new_file, &new_pos, - this_len, SPLICE_F_MOVE); + if (try_copy_file) { + bytes = new_file->f_op->copy_file_range( + old_file, old_pos, + new_file, new_pos, + len, 0); + if (bytes == -EOPNOTSUPP) { + try_copy_file = 0; + continue; + } else if (bytes > 0) { + old_pos += bytes; + new_pos += bytes; + } + } else { + bytes = do_splice_direct(old_file, &old_pos, + new_file, &new_pos, + this_len, SPLICE_F_MOVE); + } if (bytes <= 0) { error = bytes; break; -- 2.7.4