From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD666C48BE7 for ; Mon, 8 Jul 2019 07:33:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A49072084A for ; Mon, 8 Jul 2019 07:33:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728991AbfGHHd4 (ORCPT ); Mon, 8 Jul 2019 03:33:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:53536 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725840AbfGHHd4 (ORCPT ); Mon, 8 Jul 2019 03:33:56 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 847C4AC47 for ; Mon, 8 Jul 2019 07:33:55 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 0/2] btrfs-progs: Fix delayed ref leakage Date: Mon, 8 Jul 2019 15:33:50 +0800 Message-Id: <20190708073352.6095-1-wqu@suse.com> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org We have several bug reports of btrfs-convert failure in btrfs_run_delayed_refs(). The bug turns out to be a incorrect backport of delayed ref handling in transaction commit. In kernel we have a loop to exhause both delayed refs and dirty blocks, as btrfs_write_dirty_block_groups() can generate new delayed refs, while btrfs_run_delayed_refs() can re-dirty block groups. This feedback could cause missing delayed refs, and bite later transaction just like the btrfs-convert report. Furthermore, such lost delayed refs causes memory leakage and reserved space leakage, the later one can be detected by commit c31edf610cbe ("btrfs-progs: Fix false ENOSPC alert by tracking used space correctly"). The first patch will fix the long existing bug. The second patch will try to reduce the feedback between btrfs_write_dirty_block_groups() and btrfs_run_delayed_refs(). Changelog: v2: - Use a loop to exhaust both delayed refs and dirty block groups Thanks Nikolay for pointing out the feedback between them. - Add a new patch to reduce above feedback - Handle the error from btrfs_write_dirty_block_groups() Qu Wenruo (2): btrfs-progs: Exhaust delayed refs and dirty block groups to prevent delayed refs lost btrfs-progs: Avoid unnecessary block group item COW if the content hasn't changed extent-tree.c | 26 +++++++++++++++++++++++++- transaction.c | 27 +++++++++++++++++++++------ 2 files changed, 46 insertions(+), 7 deletions(-) -- 2.22.0