From patchwork Mon Jun 22 09:08:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: robbieko X-Patchwork-Id: 6654361 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B914B9F1C1 for ; Mon, 22 Jun 2015 09:11:35 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F0A1E205FE for ; Mon, 22 Jun 2015 09:11:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DB88205FC for ; Mon, 22 Jun 2015 09:11:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932876AbbFVJKR (ORCPT ); Mon, 22 Jun 2015 05:10:17 -0400 Received: from mail.synology.com ([59.124.41.242]:27298 "EHLO mail.synology.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754480AbbFVJJA (ORCPT ); Mon, 22 Jun 2015 05:09:00 -0400 Received: from localhost.localdomain (unknown [192.168.0.216]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: robbieko@synology.com) by mail.synology.com (Postfix) with ESMTPSA id 18B842B31357; Mon, 22 Jun 2015 17:08:56 +0800 (CST) From: Robbie Ko To: linux-btrfs@vger.kernel.org Cc: Robbie Ko Subject: [PATCH v2 1/7] Revert "Btrfs: incremental send, remove dead code" Date: Mon, 22 Jun 2015 17:08:42 +0800 Message-Id: <1434964128-31757-2-git-send-email-robbieko@synology.com> In-Reply-To: <1434964128-31757-1-git-send-email-robbieko@synology.com> References: <1434964128-31757-1-git-send-email-robbieko@synology.com> X-MailScanner-ID: 18B842B31357.A9ED7 X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (cached, score=2.544, required 8, ALL_TRUSTED -1.00, AWL 1.34, BAYES_05 -0.50, DNS_FROM_AHBL_RHSBL 2.70, URIBL_BLOCKED 0.00) X-MailScanner-From: robbieko@synology.com X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This reverts commit 5f806c3ae2ff6263a10a6901f97abb74dac03d36. Btrfs: incremental send, avoid ancestor rename to descendant There's one more case where we can't issue a rename operation for a directory as soon as we process it. We move a directory from ancestor to descendant. |---- a |---- b |---- c |---- d "Move a directory from ancestor to descendant" means moving dir. a into dir. c This case will happen after applying "[PATCH] Btrfs: incremental send, don't delay directory renames unnecessarily". Because, that patch changes behavior of wait_for_parent_move function. Parent snapshot: |---- @tmp/ (ino 257) |---- pre/ (ino 259) |---- wait_dir (ino 260) |---- finish_dir2/ (ino 261) |---- ance/ (ino 263) |---- finish_dir1/ (ino 258) |---- desc/ (ino 262) |---- other_dir/ (ino 264) Send snapshot: |---- @tmp/ (ino 257) |---- other_dir/ (ino 264) |---- wait_dir/ (ino 260) |---- finish_dir2/ (ino 261) |---- desc/ (ino 262) |---- ance/ (ino 263) |---- finish_dir1/ (ino 258) |---- pre/ (ino 259) 1. 259 can not move under 258 because 263 needs to move to 263 first. So 259 is waiting on ance(263). 2. 260 must move to @tmp/other_dir, so it is waiting on other_dir(264). 3. 262 is able to rename as pre/wait_dir/finish_dir2(261)/desc since wait_dir(260) is waiting and 262 is not the ancestor of wait_dir(260). 4.263 is able to rename as pre/wait_dir/finish_dir2(261)/ance since wait_dir(260) is waiting and 263 is not the ancestor of wait_dir(260). 5. After wait_dir(263) is finished, all pending dirs. start to run. /pre(259) in apply_dir_move() renames /pre as pre/wait_dir/finish_dir2/desc/ance/finish_dir1/pre At the same time, receiving side will encounter error. If anyone calls get_cur_path() to any element in pre/wait_dir/finish_dir2/desc/ance/finish_dir1/pre like wait_dir(260) , there will cause path building loop like this : 260 -> 259 -> 258 -> 263 -> 262 -> 261 -> 260 So fix the problem by check path_loop for this case. Signed-off-by: Robbie Ko --- fs/btrfs/send.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 1c1f161..257753b 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -3080,6 +3080,48 @@ static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx, return NULL; } +static int path_loop(struct send_ctx *sctx, struct fs_path *name, + u64 ino, u64 gen, u64 *ancestor_ino) +{ + int ret = 0; + u64 parent_inode = 0; + u64 parent_gen = 0; + u64 start_ino = ino; + + *ancestor_ino = 0; + while (ino != BTRFS_FIRST_FREE_OBJECTID) { + fs_path_reset(name); + + if (is_waiting_for_rm(sctx, ino)) + break; + if (is_waiting_for_move(sctx, ino)) { + if (*ancestor_ino == 0) + *ancestor_ino = ino; + ret = get_first_ref(sctx->parent_root, ino, + &parent_inode, &parent_gen, name); + } else { + ret = __get_cur_name_and_parent(sctx, ino, gen, + &parent_inode, + &parent_gen, name); + if (ret > 0) { + ret = 0; + break; + } + } + if (ret < 0) + break; + if (parent_inode == start_ino) { + ret = 1; + if (*ancestor_ino == 0) + *ancestor_ino = ino; + break; + } + ino = parent_inode; + gen = parent_gen; + } + return ret; +} + static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm) { struct fs_path *from_path = NULL; @@ -3091,6 +3133,7 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm) struct waiting_dir_move *dm = NULL; u64 rmdir_ino = 0; int ret; + u64 ancestor = 0; name = fs_path_alloc(); from_path = fs_path_alloc(); @@ -3122,6 +3165,22 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm) goto out; sctx->send_progress = sctx->cur_ino + 1; + ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor); + if (ret) { + LIST_HEAD(deleted_refs); + ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID); + ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor, + &pm->update_refs, &deleted_refs, + pm->is_orphan); + if (ret < 0) + goto out; + if (rmdir_ino) { + dm = get_waiting_dir_move(sctx, pm->ino); + ASSERT(dm); + dm->rmdir_ino = rmdir_ino; + } + goto out; + } fs_path_reset(name); to_path = name; name = NULL;