From patchwork Wed Jul 13 19:08:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 12917026 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 A2E56CCA47C for ; Wed, 13 Jul 2022 19:08:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230414AbiGMTIb (ORCPT ); Wed, 13 Jul 2022 15:08:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236502AbiGMTIb (ORCPT ); Wed, 13 Jul 2022 15:08:31 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A43C2CE16 for ; Wed, 13 Jul 2022 12:08:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2C401B8212F for ; Wed, 13 Jul 2022 19:08:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41E6AC34114; Wed, 13 Jul 2022 19:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657739307; bh=N/tOJOpwQR0cNq2NLBk4aP9ADkHWXI6eQL6rPvm93iw=; h=From:To:Cc:Subject:Date:From; b=Zsr29qbDIY1YtJrWG515ed2u1oqi79yoKGwv2aY2uRHy0BooOjfwzH/Ngga9AUkLx FNd9GkgfrWtQfY/f51btrP7rIWklPojXaMICLhY+yVERua7TSesN6orhoV6z9ZLPEh K19YT2MBQ6GtDKCYhApz5apSJeEbqlY5v5SvFqbV0AYQ/uo82I3IOQPNvTrZQ8oid/ jr9PIP2N+tBZjsTx5eoeHJmg3wU6wSs5SUXKudC6DWi+NkSORQmJchQs0XW0Lg5Sc4 BsXQrvd6LYNoO0x142oxmyWf0wLZTTPy8Cm4ebMoBGkSngBmUVOumUlKW2QNZzLep3 yTORWmazL8hjw== From: Anna Schumaker To: linux-nfs@vger.kernel.org, chuck.lever@oracle.com Cc: anna@kernel.org Subject: [PATCH v2 0/6] NFSD: Improvements for the NFSv4.2 READ_PLUS operation Date: Wed, 13 Jul 2022 15:08:19 -0400 Message-Id: <20220713190825.615678-1-anna@kernel.org> X-Mailer: git-send-email 2.37.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Anna Schumaker The main motivation for this patchset is fixing generic/091 and generic/263 with READ_PLUS. These tests appear to be failing due to files getting modified in the middle of reply encoding. Attempts to lock the file for the entire encode result in a deadlock, since llseek() and read() both need the file lock. The solution is to read everything from disk at once, and then check if each buffer page is all zeroes or not. As a bonus, this lets us support READ_PLUS hole segments on filesystems that don't track sparse files. Additionally, this also solves the performance issues I hit when testing using btrfs on a virtual machine. I created a wiki page with the results of my performance testing here: https://wiki.linux-nfs.org/wiki/index.php/Read_Plus_May_2022 These patches should probably go in before the related client changes as the client will also be changed to make use of the xdr_stream_move_subsegment() function. Changes in v2: - Update to v5.19-rc6 - Rename xdr_stream_move_segment() -> xdr_stream_move_subsegment() Thoughts? Anna Anna Schumaker (6): SUNRPC: Introduce xdr_stream_move_subsegment() SUNRPC: Introduce xdr_encode_double() SUNRPC: Introduce xdr_buf_trim_head() SUNRPC: Introduce xdr_buf_nth_page_address() SUNRPC: Export xdr_buf_pagecount() NFSD: Repeal and replace the READ_PLUS implementation fs/nfsd/nfs4xdr.c | 202 +++++++++++++++++++------------------ include/linux/sunrpc/xdr.h | 6 ++ net/sunrpc/xdr.c | 102 +++++++++++++++++++ 3 files changed, 210 insertions(+), 100 deletions(-)