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=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 ADCBEC4741F for ; Wed, 4 Nov 2020 19:59:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2425D20759 for ; Wed, 4 Nov 2020 19:59:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=natalenko.name header.i=@natalenko.name header.b="uY54IW8Q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731030AbgKDT7v (ORCPT ); Wed, 4 Nov 2020 14:59:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727013AbgKDT7v (ORCPT ); Wed, 4 Nov 2020 14:59:51 -0500 X-Greylist: delayed 393 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Wed, 04 Nov 2020 11:59:50 PST Received: from vulcan.natalenko.name (vulcan.natalenko.name [IPv6:2001:19f0:6c00:8846:5400:ff:fe0c:dfa0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFC6BC0613D3; Wed, 4 Nov 2020 11:59:50 -0800 (PST) Received: from mail.natalenko.name (vulcan.natalenko.name [IPv6:fe80::5400:ff:fe0c:dfa0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by vulcan.natalenko.name (Postfix) with ESMTPSA id 8B8D988844B; Wed, 4 Nov 2020 20:53:03 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=natalenko.name; s=dkim-20170712; t=1604519583; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hiZt2WITfKG7+QNvYDbl1KNbn6nbu5pALnEYxLoMuDo=; b=uY54IW8QF7niyKZ3TIoHQiz4ES7gQf81HJS8GQmQ9Mm5ocWUd+lLseZxIsdG36cuGrTRsP 6FH4rgyUqLvLFVcIVxz3seCOeHI4CIidRhHBy6d6NbizfubJSLNywH/cdp+i+63QOsNDfE pgUozdVlnRWF77W4RegEFUkkdGXJXNc= MIME-Version: 1.0 Date: Wed, 04 Nov 2020 20:53:03 +0100 From: Oleksandr Natalenko To: Kent Overstreet Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: bcachefs-for-review In-Reply-To: <20201027200433.GA449905@moria.home.lan> References: <20201027200433.GA449905@moria.home.lan> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <913f15a9f74615d6243391452206db53@natalenko.name> X-Sender: oleksandr@natalenko.name Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi. On 27.10.2020 21:04, Kent Overstreet wrote: > Here's where bcachefs is at and what I'd like to get merged: > > https://evilpiepirate.org/git/bcachefs.git/log/?h=bcachefs-for-review Please excuse my ignorance if I missed things in other discussions, but if this is what's expected to be reviewed, why the submission is not splitted into reviewable patches? > > Non bcachefs prep patches: > > Compiler Attributes: add __flatten > locking: SIX locks (shared/intent/exclusive) > mm: export find_get_pages_range() > mm: Add a mechanism to disable faults for a specific mapping > mm: Bring back vmalloc_exec > fs: insert_inode_locked2() > fs: factor out d_mark_tmpfile() > block: Add some exports for bcachefs > block: Add blk_status_to_str() > bcache: move closures to lib/ > closures: closure_wait_event() > > block/bio.c | 2 + > block/blk-core.c | 13 +- > drivers/md/bcache/Kconfig | 10 +- > drivers/md/bcache/Makefile | 4 +- > drivers/md/bcache/bcache.h | 2 +- > drivers/md/bcache/super.c | 1 - > drivers/md/bcache/util.h | 3 +- > fs/dcache.c | 10 +- > fs/inode.c | 40 ++ > include/linux/blkdev.h | 1 + > {drivers/md/bcache => include/linux}/closure.h | 39 +- > include/linux/compiler_attributes.h | 5 + > include/linux/dcache.h | 1 + > include/linux/fs.h | 1 + > include/linux/sched.h | 1 + > include/linux/six.h | 197 +++++++++ > include/linux/vmalloc.h | 1 + > init/init_task.c | 1 + > kernel/Kconfig.locks | 3 + > kernel/locking/Makefile | 1 + > kernel/locking/six.c | 553 > +++++++++++++++++++++++++ > kernel/module.c | 4 +- > lib/Kconfig | 3 + > lib/Kconfig.debug | 9 + > lib/Makefile | 2 + > {drivers/md/bcache => lib}/closure.c | 35 +- > mm/filemap.c | 1 + > mm/gup.c | 7 + > mm/nommu.c | 18 + > mm/vmalloc.c | 21 + > 30 files changed, 937 insertions(+), 52 deletions(-) > rename {drivers/md/bcache => include/linux}/closure.h (94%) > create mode 100644 include/linux/six.h > create mode 100644 kernel/locking/six.c > rename {drivers/md/bcache => lib}/closure.c (89%) > > New since last posting that's relevant to the rest of the kernel: > - Re: the DIO cache coherency issue, we finally have a solution that > hopefully > everyone will find palatable. We no longer try to do any fancy > recursive > locking stuff: if userspace issues a DIO read/write where the buffer > points > to the same address space as the file being read/written to, we just > return > an error. > > This requires a small change to gup.c, to add the check after the > VMA lookup. > My patch passes the mapping to check against via a new task_struct > member, > which is ugly because plumbing a new argument all the way to > __get_user_pages > is also going to be ugly and if I have to do that I'm likely to go > on a > refactoring binge, which gup.c looks like it needs anyways. > > - vmalloc_exec() is needed because bcachefs dynamically generates x86 > machine > code - per btree node unpack functions. > > Bcachefs changes since last posting: > - lots > - reflink is done > - erasure coding (reed solomon raid5/6) is maturing; I have declared > it ready > for beta testers and gotten some _very_ positive feedback on its > performance. > - btree key cache code is done and merged, big improvements to > multithreaded > write workloads > - inline data extents > - major improvements to how the btree code handles extents (still > todo: > re-implement extent merging) > - huge improvements to mount/unmount times on huge filesystems > - many, many bugfixes; bug reports are slowing and the bugs that are > being > reported look less and less concerning. In particular repair code is > getting > better and more polished. > > TODO: > - scrub, repair of replicated data when one of the replicas fail the > checksum > check > - erasure coding needs repair code (it'll do reconstruct reads, but we > don't > have code to rewrite bad blocks in a stripe yet. this is going to be > a hassle > until we get backpointers) > - fsck isn't checking refcounts of reflinked extents yet > - bcachefs tests in ktest need to be moved to xfstests > - user docs are still very minimal > > So that's roughly where things are at. I think erasure coding is going > to to be > bcachefs's killer feature (or at least one of them), and I'm pretty > excited > about it: it's a completely new approach unlike ZFS and btrfs, no write > hole (we > don't update existing stripes in place) and we don't have to fragment > writes > either like ZFS does. Add to that the caching that we already do and > it's > turning into a pretty amazing tool for managing a whole bunch of mixed > storage. -- Oleksandr Natalenko (post-factum)