From patchwork Mon Jun 22 09:08:44 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: robbieko X-Patchwork-Id: 6654341 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4B1C2C05AC for ; Mon, 22 Jun 2015 09:10:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 856B7205FC for ; Mon, 22 Jun 2015 09:10:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E5C92062D for ; Mon, 22 Jun 2015 09:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932425AbbFVJJB (ORCPT ); Mon, 22 Jun 2015 05:09:01 -0400 Received: from mail.synology.com ([59.124.41.242]:1272 "EHLO mail.synology.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752521AbbFVJI7 (ORCPT ); Mon, 22 Jun 2015 05:08:59 -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 C43612B30AEC; Mon, 22 Jun 2015 17:08:57 +0800 (CST) From: Robbie Ko To: linux-btrfs@vger.kernel.org Cc: Robbie Ko Subject: [PATCH v2 3/7] Btrfs: incremental send, avoid ancestor rename to descendant Date: Mon, 22 Jun 2015 17:08:44 +0800 Message-Id: <1434964128-31757-4-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: C43612B30AEC.A8788 X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (cached, score=2.518, required 8, ALL_TRUSTED -1.00, AWL 1.32, 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 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. Example: Parent snapshot: |---- @tmp/ (ino 257) |---- pre/ (ino 260) |---- wait_dir (ino 261) |---- ance/ (ino 263) |---- wait_at_below_ance/ (ino 259) |---- desc/ (ino 262) |---- other_dir/ (ino 264) Send snapshot: |---- @tmp/ (ino 257) |---- other_dir/ (ino 264) |---- wait_at_below_ance/ (ino 259) |---- pre/ (ino 260) |---- wait_dir/ (ino 261) |---- desc/ (ino 262) |---- ance/ (ino 263) 1. 259 must move to @tmp/other_dir, so it is waiting on other_dir(264). 2. 260 is able to rename as ance/wait_at_below_ance/pre since wait_at_below_ance(259) is waiting and 260 is not the ancestor of wait_at_below_ance(259). 3. 261 must move to @tmp/other_dir, so it is waiting on other_dir(264). 4. 262 is able to rename as ance/wait_at_below_ance/pre/wait_dir/desc since wait_dir(261) is waiting and 262 is not the ancestor of wait_dir(261). 5. 263 is rename as ance/wait_at_below_ance/pre/wait_dir/desc/ance since wait_dir(261) is waiting and 263 is not the ancestor of wait_dir(261). At the same time, receiving side will encounter error. If anyone calls get_cur_path() to any element in ance/wait_at_below_ance/pre/wait_dir/desc/ance like wait_dir(260), there will cause path building loop like this : 261 -> 260 -> 259 -> 263 -> 262 -> 261 So fix the problem by check path_loop for this case. Signed-off-by: Robbie Ko --- V2: Always check path_loop, and check Allocation ret value. fs/btrfs/send.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 44ad144..b946067 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -3088,15 +3088,23 @@ static int path_loop(struct send_ctx *sctx, struct fs_path *name, *ancestor_ino = 0; while (ino != BTRFS_FIRST_FREE_OBJECTID) { + struct waiting_dir_move *wdm; fs_path_reset(name); if (is_waiting_for_rm(sctx, ino)) break; - if (is_waiting_for_move(sctx, ino)) { + + wdm = get_waiting_dir_move(sctx, ino); + if (wdm) { if (*ancestor_ino == 0) *ancestor_ino = ino; - ret = get_first_ref(sctx->parent_root, ino, - &parent_inode, &parent_gen, name); + if (wdm->orphanized) { + ret = gen_unique_name(sctx, ino, gen, name); + break; + } else { + 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, @@ -3743,6 +3751,38 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); } /* + * if cur_ino is cur ancestor, can't move now, + * find descendant who is waiting, waiting it. + */ + if(can_rename) { + struct fs_path *name = NULL; + u64 ancestor; + u64 old_send_progress = sctx->send_progress; + + name = fs_path_alloc(); + if (!valid_path) { + ret = -ENOMEM; + goto out; + } + + sctx->send_progress = sctx->cur_ino + 1; + ret = path_loop(sctx, name, sctx->cur_ino, sctx->cur_inode_gen, &ancestor); + if (ret) { + ret = add_pending_dir_move(sctx, sctx->cur_ino, sctx->cur_inode_gen, + ancestor, &sctx->new_refs, &sctx->deleted_refs, is_orphan); + if (ret < 0) { + sctx->send_progress = old_send_progress; + fs_path_free(name); + goto out; + } + can_rename = false; + *pending_move = 1; + } + sctx->send_progress = old_send_progress; + fs_path_free(name); + } + + /* * link/move the ref to the new place. If we have an orphan * inode, move it and update valid_path. If not, link or move * it depending on the inode mode.