From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:32779 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761915AbcINMoA (ORCPT ); Wed, 14 Sep 2016 08:44:00 -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 v3 4/4] ovl: use vfs_copy_file_range() to copy up file data Date: Wed, 14 Sep 2016 15:43:14 +0300 Message-Id: <1473856994-27463-5-git-send-email-amir73il@gmail.com> In-Reply-To: <1473856994-27463-1-git-send-email-amir73il@gmail.com> References: <1473856994-27463-1-git-send-email-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Use vfs_copy_file_range() helper instead of calling do_splice_direct() when copying up file data. When copying up within the same fs, which supports copy_file_range(), fs implementation can be more efficient then do_splice_direct(). vfs_copy_file_range() helper falls back to do_splice_direct() if it cannot use the file system's copy_file_range() implementation. A previous change added a vfs_clone_file_range() call before the data copy loop, so this change is only effective for filesystems that support copy_file_range() and *do not* support clone_file_range(). At the moment, there are no such filesystems in the kernel that can be used as overlayfs upper, so I tested this change by disabling the vfs_clone_file_range() call. 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 (reflink) 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 +++++----- fs/read_write.c | 1 + 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index ba039f8..a6d6bac 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -146,7 +146,6 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) /* Can't clone, so now we try to copy the data */ error = 0; - /* FIXME: copy up sparse files efficiently */ while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; long bytes; @@ -159,15 +158,16 @@ 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); + bytes = vfs_copy_file_range(old_file, old_pos, + new_file, new_pos, + this_len, 0); if (bytes <= 0) { error = bytes; break; } - WARN_ON(old_pos != new_pos); + old_pos += bytes; + new_pos += bytes; len -= bytes; } out: diff --git a/fs/read_write.c b/fs/read_write.c index 6975fe8..dfc083a 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1515,6 +1515,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, file_out->f_op->copy_file_range) ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, pos_out, len, flags); + /* FIXME: copy sparse file range efficiently */ if (ret == -EOPNOTSUPP) ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); -- 2.7.4