From patchwork Fri Oct 28 01:40:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: robbieko X-Patchwork-Id: 9400737 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 0970A605EE for ; Fri, 28 Oct 2016 01:41:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED1022A42E for ; Fri, 28 Oct 2016 01:41:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E04472A431; Fri, 28 Oct 2016 01:41:29 +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 A98C42A42E for ; Fri, 28 Oct 2016 01:41:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964812AbcJ1BlZ (ORCPT ); Thu, 27 Oct 2016 21:41:25 -0400 Received: from synology.com ([59.124.61.242]:36651 "EHLO synology.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S943100AbcJ1BlY (ORCPT ); Thu, 27 Oct 2016 21:41:24 -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 67F1C131605D6; Fri, 28 Oct 2016 09:41:16 +0800 (CST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synology.com; s=123; t=1477618876; bh=K+xqpzK6L5F2XpS9j7tASulNEMsMMxVuxwT3LpkP4Yw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Yk1HNnIF+oEI/V09zAODDIRkCP9bT98dzA3OgkY/F2sImUIcqj0FybJM42FyM3P5i gy2WUgd0pA5AVCoHd1bTvNm53PQp/PvqjGjJ+UzR6pTLNNqskfbhugx7jDOQ4cXGqI 9gno2kymDiTqmcpuJExl7RZXztvZcJNmBNxeRrsE= From: robbieko To: linux-btrfs@vger.kernel.org Cc: Robbie Ko Subject: [PATCH v2 3/6] Btrfs: incremental send, add generation for waiting_dir_move struct and check it in can_rmdir. Date: Fri, 28 Oct 2016 09:40:47 +0800 Message-Id: <1477618850-12922-4-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: 67F1C131605D6.A5E25 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: |---- dir258/ (ino 258, gen 27) |---- dir257/ (ino 257, gen 27) |---- dir259/ (ino 259, gen 27) Send snapshot: |---- new_dir259/ (ino 259, gen 38) |---- new_dir258/ (ino 258, gen 38) |---- new_dir257/ (ino 257, gen 38) rmdir dir258/dir257 mkdir o257-38-0 mkdir o258-38-0 chown o257-38-0 - uid=0, gid=0 chmod o257-38-0 - mode=0755 rename dir258 -> o258-27-0 -----> dir is empty, but waiting o257-38-0 mkdir o259-38-0 chown o258-38-0 - uid=0, gid=0 chmod o258-38-0 - mode=0755 rmdir dir259 rename o259-38-0 -> new_dir259 utimes chown new_dir259 - uid=0, gid=0 chmod new_dir259 - mode=0755 rename o258-38-0 -> new_dir259/new_dir258 utimes new_dir259/new_dir258 utimes new_dir259 rename o257-38-0 -> new_dir259/new_dir258/new_dir257 rmdir o258-27-0 -----> when o257-38-0 finish, delete utimes new_dir259/new_dir258/new_dir257 utimes new_dir259/new_dir258 utimes new_dir259 While computing the send stream the following steps happen: 1) While processing inode 257 we delete dir258/dir257 immediately. After create o257-38-0, we then delay its rename operation because its new parent in the send snapshot, inode 258, was not yet processed and therefore not yet renamed. 2) On processing inode 258, we need to check if all under files are done before rmdir dir258. However, the waiting o257-38-0 (ino 257) will mislead the check making it think dir257 (ino 257) is still there. dir258 will be orphanized at first but in fact it has become empty. Fix this by adding generation to waiting_dir_move struct, so can_rmdir can use it to correct the result. Signed-off-by: Robbie Ko --- fs/btrfs/send.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 22eca86..eaf1c92 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -237,6 +237,7 @@ struct pending_dir_move { struct waiting_dir_move { struct rb_node node; u64 ino; + u64 gen; /* * There might be some directory that could not be removed because it * was waiting for this directory inode to be moved first. Therefore @@ -2930,6 +2931,7 @@ static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen, struct btrfs_key found_key; struct btrfs_key loc; struct btrfs_dir_item *di; + u64 gen; /* * Don't try to rmdir the top/root subvolume dir. @@ -2969,8 +2971,13 @@ static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen, struct btrfs_dir_item); btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc); + ret = get_inode_info(root, loc.objectid, NULL, &gen, NULL, + NULL, NULL, NULL); + if (ret < 0) + goto out; + dm = get_waiting_dir_move(sctx, loc.objectid); - if (dm) { + if (dm && dm->gen == gen) { struct orphan_dir_info *odi; odi = add_orphan_dir_info(sctx, dir); @@ -3010,7 +3017,8 @@ static int is_waiting_for_move(struct send_ctx *sctx, u64 ino) return entry != NULL; } -static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized) +static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, u64 gen, + bool orphanized) { struct rb_node **p = &sctx->waiting_dir_moves.rb_node; struct rb_node *parent = NULL; @@ -3020,6 +3028,7 @@ static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized) if (!dm) return -ENOMEM; dm->ino = ino; + dm->gen = gen; dm->rmdir_ino = 0; dm->orphanized = orphanized; @@ -3117,7 +3126,7 @@ static int add_pending_dir_move(struct send_ctx *sctx, goto out; } - ret = add_waiting_dir_move(sctx, pm->ino, is_orphan); + ret = add_waiting_dir_move(sctx, pm->ino, pm->gen, is_orphan); if (ret) goto out;