From patchwork Fri Oct 28 01:40:45 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: robbieko X-Patchwork-Id: 9400743 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 842D3605EE for ; Fri, 28 Oct 2016 01:41:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 757D12A422 for ; Fri, 28 Oct 2016 01:41:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6A7602A42E; Fri, 28 Oct 2016 01:41:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DE7C72A422 for ; Fri, 28 Oct 2016 01:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965092AbcJ1Bl2 (ORCPT ); Thu, 27 Oct 2016 21:41:28 -0400 Received: from synology.com ([59.124.61.242]:36935 "EHLO synology.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964918AbcJ1Bl1 (ORCPT ); Thu, 27 Oct 2016 21:41:27 -0400 Received: from localhost.localdomain (unknown [10.12.12.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: robbieko@synology.com) by synology.com (Postfix) with ESMTPSA id 0B94E131602C4; Fri, 28 Oct 2016 09:41:15 +0800 (CST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synology.com; s=123; t=1477618875; bh=u+KiiLRQBD2oNIDwefwjVBPS/c159aLVcxptIjMKid0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=M6bPJUWiWWlyNxw23z+35lY+TDOGzhInf1d8rgthnWgbv6L7/L2NuMGhmGBsJ/7Q+ sKXf4RE32StWwGlMQpszaYhA08z8ccJtxJ65r8yTzisNq8bLk2vW/TiLgfPdfDM3SC xqJF6IlQLxZhfpEdTORrFn5OY+TGg/IPHcAE4E4U= From: robbieko To: linux-btrfs@vger.kernel.org Cc: Robbie Ko Subject: [PATCH v2 1/6] Btrfs: incremental send, do not skip generation inconsistency check for inode 256. Date: Fri, 28 Oct 2016 09:40:45 +0800 Message-Id: <1477618850-12922-2-git-send-email-robbieko@synology.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1477618850-12922-1-git-send-email-robbieko@synology.com> References: <1477618850-12922-1-git-send-email-robbieko@synology.com> X-MailScanner-ID: 0B94E131602C4.A8317 X-MailScanner: Found to be clean X-MailScanner-MCPCheck: MCP-Clean, MCP-Checker (score=0, required 80) X-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (not cached, score=-0.891, required 4.5, ALL_TRUSTED -1.00, BAYES_40 -0.00, DKIM_SIGNED 0.10, T_DKIM_INVALID 0.01) X-MailScanner-From: robbieko@synology.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Robbie Ko Example scenario: Parent snapshot: |. (ino 256, gen 5) |---- a1/ (ino 257, gen 5) |---- a2/ (ino 258, gen 5) Send snapshot: |. (ino 256, gen 7) |---- a2 (ino 257, gen 7) rmdir a1 mkfile o257-7-0 rename o257-7-0 -> a2 ERROR: rename o257-7-0 -> a2 failed: Is a directory While computing the send stream the following steps happen: 1) delete a1; 2) mkfile o257-7-0; 3) rename o257-7-0->a2; In step 3 we will check whether it will lead to overwrite. The generation number of inode 257's parent (ino 256) in send snapshot is 7, which is inconsistent with the one in parent snapshot (gen 5). For the general parent directory except inode 256, if its generation is not identical between parent and send snapshot, it will be removed then created. Thus it's not possible to happen overwrite under the new directory. However for the special inode 256, the above logic does not work since it is a subvolume. So overwrite check is required for the inode 256. Fix by skipping generation inconsistency check for inode 256. Signed-off-by: Robbie Ko --- fs/btrfs/send.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index a87675f..2060e75 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1681,6 +1681,9 @@ static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen) { int ret; + if (ino == BTRFS_FIRST_FREE_OBJECTID) + return 1; + ret = get_cur_inode_state(sctx, ino, gen); if (ret < 0) goto out; @@ -1866,7 +1869,7 @@ static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen, * not deleted and then re-created, if it was then we have no overwrite * and we can just unlink this entry. */ - if (sctx->parent_root) { + if (sctx->parent_root && dir != BTRFS_FIRST_FREE_OBJECTID) { ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL, NULL, NULL, NULL); if (ret < 0 && ret != -ENOENT)