From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:30202 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753594AbbFDVRh (ORCPT ); Thu, 4 Jun 2015 17:17:37 -0400 Received: from pps.filterd (m0004347 [127.0.0.1]) by m0004347.ppops.net (8.14.5/8.14.5) with SMTP id t54LGnNT012359 for ; Thu, 4 Jun 2015 14:17:36 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by m0004347.ppops.net with ESMTP id 1utumu0acn-9 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT) for ; Thu, 04 Jun 2015 14:17:36 -0700 From: Josef Bacik To: Subject: [PATCH] Btrfs: use received_uuid of parent during send Date: Thu, 4 Jun 2015 17:17:25 -0400 Message-ID: <1433452645-7904-1-git-send-email-jbacik@fb.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: Neil Horman pointed out a problem where if he did something like this receive A snap A B change B send -p A B and then on another box do recieve A receive B the receive B would fail because we use the UUID of A for the clone sources for B. This makes sense most of the time because normally you are sending from the original sources, not a received source. However when you use a recieved subvol its UUID is going to be something completely different, so if you then try to receive the diff on a different volume it won't find the UUID because the new A will be something else. The only constant is the received uuid. So instead check to see if we have received_uuid set on the root, and if so use that as the clone source, as btrfs receive looks for matches either in received_uuid or uuid. Thanks, Reported-by: Neil Horman Signed-off-by: Josef Bacik --- fs/btrfs/send.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index a1216f9..947d91c 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -2328,8 +2328,12 @@ static int send_subvol_begin(struct send_ctx *sctx) TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID, le64_to_cpu(sctx->send_root->root_item.ctransid)); if (parent_root) { - TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, - sctx->parent_root->root_item.uuid); + if (!btrfs_is_empty_uuid(parent_root->root_item.received_uuid)) + TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, + parent_root->root_item.received_uuid); + else + TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, + parent_root->root_item.uuid); TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID, le64_to_cpu(sctx->parent_root->root_item.ctransid)); } @@ -4508,8 +4512,21 @@ verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, " if (ret < 0) goto out; - TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, - clone_root->root->root_item.uuid); + /* + * If the parent we're using has a received_uuid set then use that as + * our clone source as that is what we will look for when doing a + * receive. + * + * This covers the case that we create a snapshot off of a received + * subvolume and then use that as the parent and try to receive on a + * different host. + */ + if (!btrfs_is_empty_uuid(clone_root->root->root_item.received_uuid)) + TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, + clone_root->root->root_item.received_uuid); + else + TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, + clone_root->root->root_item.uuid); TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID, le64_to_cpu(clone_root->root->root_item.ctransid)); TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p); -- 1.8.3.1