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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AFEA3C49ED7 for ; Thu, 19 Sep 2019 06:54:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8422A21924 for ; Thu, 19 Sep 2019 06:54:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=osandov-com.20150623.gappssmtp.com header.i=@osandov-com.20150623.gappssmtp.com header.b="y8ajRS9o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731690AbfISGx7 (ORCPT ); Thu, 19 Sep 2019 02:53:59 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:35639 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731504AbfISGx7 (ORCPT ); Thu, 19 Sep 2019 02:53:59 -0400 Received: by mail-pf1-f195.google.com with SMTP id 205so1647484pfw.2 for ; Wed, 18 Sep 2019 23:53:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osandov-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dUUhMDT2yBGZdNqjQ9RKk1UhdRgrpXRQODGGuHoUiyU=; b=y8ajRS9oUVZ1bADIkM7x4Gf/BkdDJbsd0JE9Z3OdUZRSMdqPOM1FMo39DHHxAkNlf+ tX9WuSpS5U+pACa0z+N818dx4UZuw0DdrRNY6N1N8SIAMH6v+6cEyclfjcnZ2AOY6KSy wMydZ5L98lZ5KAIPf7NPSJCiqEE909fQqzvSeYz3Vw/yjnnZXpXNJrfcFpyWiZ/tDUPr jKjwVz+orcnYl0w0VUpgiUWJXkkM2mD67xuxPmiiIVE8Mm1yRQ2fHYw/He3fvcZOVQ7m aDHDZHqsK93do+wi8b/t1RgUIQr6pLL7Zhb+zriMRFz6h6gajUU4etR5foS0CcyJhdUv N79w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dUUhMDT2yBGZdNqjQ9RKk1UhdRgrpXRQODGGuHoUiyU=; b=mVAwKkev5yJiaSt6kyXaIRXwMenFPQozRyn1Gieqoun6pgtk9jJD7040Bv8TLk0pGo BQtkzFVUA/N6/ZSjs0M7kK0ncW1pr1pOf+uwA7WKj+wf7QgRJXnFmjuKNQxIw6SW9yFU fddUN8wv8RmRA9quSGcbhvCuRMYXzlvW2xlzrPVHFE7ilJrdOLPIj8muhjtKHHkdMh/t f8fgemFqt9draEKAOgtLpoW8igiZzyb7WVmh8e53wWWiijXwRZMCwZf3VRodEx/OXv2f G4VPg0PIYTVftU2bx11E11VmcQZ1L0HawgL11n1H/x+nQhEsfFZ1+kQzRBt8VB3l95L9 YbRw== X-Gm-Message-State: APjAAAWE/73FxaHZGEpB8rFIBsZhB667FWkoReXc7k97v5EgTcxCNzGy uPVGE1M1xv0MnzJupN2dZdfpzrm/BTM= X-Google-Smtp-Source: APXvYqyPlQLlGr03xTZPu5fxpHXDm0f0L1rUjv9PyUrVtZVxo0n1K+iVfmM/ITE1KrEVNLcIHJIwDg== X-Received: by 2002:a63:c203:: with SMTP id b3mr7764841pgd.450.1568876036487; Wed, 18 Sep 2019 23:53:56 -0700 (PDT) Received: from vader.thefacebook.com ([2620:10d:c090:180::332b]) by smtp.gmail.com with ESMTPSA id m24sm6623615pgj.71.2019.09.18.23.53.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Sep 2019 23:53:55 -0700 (PDT) From: Omar Sandoval To: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org Cc: Dave Chinner , linux-api@vger.kernel.org, kernel-team@fb.com Subject: [RFC PATCH 0/3] fs: interface for directly writing encoded (e.g., compressed) data Date: Wed, 18 Sep 2019 23:53:43 -0700 Message-Id: X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Omar Sandoval Hello, This patch series adds an API for writing compressed data directly to the filesystem. It is based on my previous series which added a Btrfs-specific ioctl [1], but this is now an extension to pwritev2() as suggested by Dave Chinner [2]. I've included a man page patch describing the API in detail. A test case and example program are available [3]. The use case that I have in mind is Btrfs send/receive: currently, when sending data from one compressed filesystem to another, the sending side decompresses the data and the receiving side recompresses it before writing it out. This is wasteful and can be avoided if we can just send and write compressed extents. The send part will be implemented in a separate series, as this API can stand alone. Patch 1 is a prep patch. Patch 2 adds the interface in the VFS. Patch 3 implements it in Btrfs. This series is based on Linus' tree as of commit b41dae061bbd722b9d7fa828f35d22035b218e18. Please share any comments on the API or implementation. Thanks! 1: https://lore.kernel.org/linux-fsdevel/cover.1567623877.git.osandov@fb.com/ 2: https://lore.kernel.org/linux-fsdevel/20190906212710.GI7452@vader/ 3: https://github.com/osandov/xfstests/tree/btrfs-compressed-write Omar Sandoval (3): fs: pass READ/WRITE to kiocb_set_rw_flags() fs: add RWF_ENCODED for writing compressed data btrfs: implement encoded (compressed) writes fs/aio.c | 9 +- fs/btrfs/compression.c | 6 +- fs/btrfs/compression.h | 5 +- fs/btrfs/ctree.h | 4 + fs/btrfs/file.c | 40 +++++++-- fs/btrfs/inode.c | 190 +++++++++++++++++++++++++++++++++++++++- fs/io_uring.c | 9 +- fs/read_write.c | 2 +- include/linux/fs.h | 18 +++- include/uapi/linux/fs.h | 24 ++++- mm/filemap.c | 75 +++++++++++++--- 11 files changed, 344 insertions(+), 38 deletions(-) -- 2.23.0