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 42DAEC433F5 for ; Wed, 16 Feb 2022 07:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230443AbiBPHpG (ORCPT ); Wed, 16 Feb 2022 02:45:06 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:34010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230439AbiBPHpE (ORCPT ); Wed, 16 Feb 2022 02:45:04 -0500 Received: from mail-qv1-xf35.google.com (mail-qv1-xf35.google.com [IPv6:2607:f8b0:4864:20::f35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 634F019FB1C; Tue, 15 Feb 2022 23:44:48 -0800 (PST) Received: by mail-qv1-xf35.google.com with SMTP id f19so1397421qvb.6; Tue, 15 Feb 2022 23:44:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:subject:message-id:mime-version:content-disposition; bh=UWEGrk+MNpARhvbHzf+0g0kbbtIVAtwr34HOg+Y5lQ8=; b=C+OB9n0G4yzpDcvquHEP75OsJsd5/Q+aKf3O2aGNS0GlZ97qy1HxD1ckACWlyc3FiA Lbezk2QubuMq2BNnYZrR2Z8ADcD/4bDIO/LwjCTqFfPR47svSBnASq2GWjFwuSnuy0Bq cveZvmB6FJEsIjpAXOY85UfCMsm2/EYzL+aq9wmKJcMZrYxZKqjO/sxT/DanTJHrFlov K05/jvbD8IwKK9xRcpAPqr5tfjlA37IQfnK4K01hzjS8mR+6pRuJAUDZYF8jjLxwDUjc 2iLydAyhPf1B39aGhsQkldKZV1buNO8KifSBpvB2+o+2bFSJhf0I2jpQvGjvlTYPQflo vUmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-disposition; bh=UWEGrk+MNpARhvbHzf+0g0kbbtIVAtwr34HOg+Y5lQ8=; b=yvZr3naBitOupErgThEpMYq6qloqV2rvmtae5WKiT0mnq3zfPabRTJHS/cvGofikBU WEvhsiK4bfhB26WQonh9U20QaxkPhNKPT65dRNGW1Bd/YAllomG/dkE7auaOg/vdNpuj 4ZupyKDAxf2DcbaNYTDBp1lO+yJTYDZ9ftFPkrC2pXWVhieLcnCZgwoPxa9FI3MgIHaJ 823ZUclplNYUjYl+wHXvfq3KFdE+1FeAaLFLeD9NQdRnClIIrSeaYeod0kyZDQ/NwXWr nrc4IE4sMXDgb9wCFH4cj92jhpR5Zns+VR9/fVhBaGQpnblVICWmRhYDsSqRWCZUwAP9 dLYw== X-Gm-Message-State: AOAM5305XDuFRKqxfpFHCXQdFnqCfaAQHOJ43BZOyUS5y/qtYEDcInRk 7ByoHRHrJrErkEaaDYtB+XJVVKmFYA== X-Google-Smtp-Source: ABdhPJxsbDjRuJvF5LEmbr3ifWA1U3ttEPmd/+1OwW5iNVilh29ICip3BeCVK7EhOlE8lF4p+wS6Pw== X-Received: by 2002:ad4:4f83:0:b0:42f:5997:d3de with SMTP id em3-20020ad44f83000000b0042f5997d3demr1034511qvb.82.1644997478729; Tue, 15 Feb 2022 23:44:38 -0800 (PST) Received: from zaphod.evilpiepirate.org (c-73-219-103-14.hsd1.vt.comcast.net. [73.219.103.14]) by smtp.gmail.com with ESMTPSA id 22sm22037811qtw.75.2022.02.15.23.44.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Feb 2022 23:44:37 -0800 (PST) Date: Wed, 16 Feb 2022 02:44:33 -0500 From: Kent Overstreet To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, lsf-pc@lists.linux-foundation.org Subject: [LSF/MM/BPF TOPIC] bcachefs Message-ID: <20220216074433.u726dkh2q2wdtwne@zaphod.evilpiepirate.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi, I'd like to come give an update on bcachefs. It's been a long road going from bcache, and starting with what was essentially a prototype for a new filesystem, and turning it into a real (scalable, robust, full featured) filesystem. Over the past few years, we've added reflink, subvolumes and snapshots. I'm particularly proud of how snapshots turned out - it's roughly a versioned btree approach, and it's scalable and fast, even fsck is O(number of keys of metadata), not O(number of snapshots). I've got it up to a million snapshots in a test VM. The bigger thing though is that the core fundamentals are pretty close to done - replacing all the "periodically walk the world" algorigthms with real persistent data structures that scale. A big allocator rewrite is about to land, and after that will be backpointers - to fix copygc scanning. Things are in flux lately with all the allocator work, but I'm hoping once that settles down and I've worked through the backlog of bug reports and performance regressions, we might be ready for upstreaming sometime this year...