From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ia0-f175.google.com ([209.85.210.175]:45754 "EHLO mail-ia0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754183Ab3AIRjn (ORCPT ); Wed, 9 Jan 2013 12:39:43 -0500 Received: by mail-ia0-f175.google.com with SMTP id 21so1561578iay.20 for ; Wed, 09 Jan 2013 09:39:43 -0800 (PST) MIME-Version: 1.0 Date: Wed, 9 Jan 2013 19:39:43 +0200 Message-ID: Subject: [PATCH 1/2] Avoid sending disknr==0 extents when possible From: Alex Lyakas To: Alexander Block , Jan Schmidt , linux-btrfs Cc: Arne Jansen , Chen Yang Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: In-Reply-To: Subject: [PATCH 1/2] Avoid sending disknr==0 extents in the following cases: 1) full send 2) new inode in a diff-send 3) when disknr==0 extents are added to the end of an inode Original-version-by: Chen Yang Signed-off-by: Alex Lyakas --- fs/btrfs/send.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 5445454..5ab584f 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -3844,7 +3844,8 @@ static int is_extent_unchanged(struct send_ctx *sctx, btrfs_item_key_to_cpu(eb, &found_key, slot); if (found_key.objectid != key.objectid || found_key.type != key.type) { - ret = 0; + /* No need to send a no-data extent it in this case */ + ret = (left_disknr == 0) ? 1 : 0; goto out; } @@ -3870,7 +3871,8 @@ static int is_extent_unchanged(struct send_ctx *sctx, * This may only happen on the first iteration. */ if (found_key.offset + right_len <= ekey->offset) { - ret = 0; + /* No need to send a no-data extent it in this case */ + ret = (left_disknr == 0) ? 1 : 0; goto out; } @@ -3951,6 +3953,28 @@ static int process_extent(struct send_ctx *sctx, ret = 0; goto out; } + } else { + struct extent_buffer *eb; + struct btrfs_file_extent_item *ei; + u8 extent_type; + u64 extent_disknr; + + eb = path->nodes[0]; + ei = btrfs_item_ptr(eb, path->slots[0], + struct btrfs_file_extent_item); + + extent_type = btrfs_file_extent_type(eb, ei); + extent_disknr = btrfs_file_extent_disk_bytenr(eb, ei); + if (extent_type == BTRFS_FILE_EXTENT_REG && extent_disknr == 0) { + /* + * This is disknr=0 extent in a full-send or a new inode + * in a diff-send. Since we will send truncate command + * in finish_inode_if_needed anyways, the inode size will be + * correct, and we don't have to send all-zero data. + */ + ret = 0; + goto out; + } } ret = find_extent_clone(sctx, path, key->objectid, key->offset, -- 1.7.9.5