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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB112C4332F for ; Thu, 2 Nov 2023 02:50:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343500AbjKBCuC (ORCPT ); Wed, 1 Nov 2023 22:50:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232987AbjKBCuB (ORCPT ); Wed, 1 Nov 2023 22:50:01 -0400 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [IPv6:2001:41d0:203:375::aa]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16E82D6D for ; Wed, 1 Nov 2023 19:49:33 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1698893371; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=qYhbDEbRImDFxWLyQ5jW3LGLBp49+S6xGSZrrMSPQPc=; b=YUUpfFEofwjU/yc4dxtn3G1PzUasr6QgkPeObGMLGadf1aiTgcGaYdDiXx90gk7/vL4CZW k5XepKy0d1BGZclaMXhG9PniOAOzqEU+wIxW23wqF0jZuTv5ipQkVF0UIfKJf5FdjXRG7L VRXppRRBgJQFcDwn1ZKD0W7Zd/6Mo6Y= From: Kent Overstreet To: linux-bcachefs@vger.kernel.org Cc: Kent Overstreet Subject: [PATCH 0/2] Split brain detection Date: Wed, 1 Nov 2023 22:49:18 -0400 Message-ID: <20231102024924.4107287-1-kent.overstreet@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-bcachefs@vger.kernel.org Two patch series for split brain detection: that is, detect when different members of a filesystem have been used, independently, in degraded mode and diverged - when that happens we can no longer use those members in combination. First patch adds superblock facilities: we add a superblock sequence number field to bch_member, and a write time field to the superblock to detect cases when sb->seq is equal but they actually have diverged. Second patch does the actual split brain detection and kicking out of devices when necessary. Kent Overstreet (2): bcachefs: bch_member->seq bcachefs: Split brain detection fs/bcachefs/bcachefs_format.h | 4 ++- fs/bcachefs/errcode.h | 1 + fs/bcachefs/sb-members.c | 5 ++++ fs/bcachefs/super-io.c | 10 +++++++ fs/bcachefs/super.c | 56 ++++++++++++++++++++++++++++------- 5 files changed, 64 insertions(+), 12 deletions(-) -- 2.42.0