From patchwork Wed Jul 15 15:10:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Wysochanski X-Patchwork-Id: 11665743 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BD9FA138C for ; Wed, 15 Jul 2020 15:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6D472065D for ; Wed, 15 Jul 2020 15:11:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fg5UBcRN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726661AbgGOPLv (ORCPT ); Wed, 15 Jul 2020 11:11:51 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:41781 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725992AbgGOPLv (ORCPT ); Wed, 15 Jul 2020 11:11:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594825909; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=kiP9/hkrOoyToSpFjJqZnI1/ilc2c2i/joUZgMCxTQc=; b=Fg5UBcRNBNgTP8Q7YaolaW+tbmewGYlSlBDCDEL0R9i9k1KXdDKT69guqiSvw7Edby4/PT h7UZxk6eB3bhwbDqHPG3VysKsO1DxlSfg18tFfYECCFObyab7ErQhHkIc4o0wqF+44la7E bBFqrZzj82JRolDWyUZu9qWtKP+MC9E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-194-l6r8wVIXPn2O1vlNxeIIxA-1; Wed, 15 Jul 2020 11:11:44 -0400 X-MC-Unique: l6r8wVIXPn2O1vlNxeIIxA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 891AE8027F7; Wed, 15 Jul 2020 15:10:51 +0000 (UTC) Received: from dwysocha.rdu.csb (ovpn-118-79.rdu2.redhat.com [10.10.118.79]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1C05560BF1; Wed, 15 Jul 2020 15:10:50 +0000 (UTC) From: Dave Wysochanski To: Trond Myklebust , Anna Schumaker Cc: linux-nfs@vger.kernel.org, linux-cachefs@redhat.com Subject: [RFC PATCH v1 0/13] Convert NFS client to new fscache-iter API Date: Wed, 15 Jul 2020 11:10:36 -0400 Message-Id: <1594825849-24991-1-git-send-email-dwysocha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org These patches update the nfs client to use the new FS-Cache API and are at: https://github.com/DaveWysochanskiRH/kernel/commit/a426b431873ea755c94ccd403aeaba0c4e635016 They are based on David Howells fscache-iter tree at ff12b5a05bd6984ad83e762f702cb655222bad74 https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit/?h=fscache-iter&id=ff12b5a05bd6984ad83e762f702cb655222bad74 The following patches may be of specific interest to review as they are related to the conversion: NFS: Convert fscache_acquire_cookie and fscache_relinquish_cookie NFS: Convert nfs_readpage() and readpages() to new fscache API NFS: Only use and unuse an fscache cookie a single time based on NFS_INO_FSCACHE NFS: Convert fscache invalidation and update aux_data and i_size Note that this is only a "first pass" v1 / RFC set I wanted to get out there for the maintainers to see and know this is being worked on. It is far from perfect and has some problems still need worked out. A short summary of this set: 1. Takes a "least invasive to existing code" approach * most fscache bits stay fs/nfs/fscache.[ch] * fscache enable/disable switched inside NFS code on nfs_inode.fscache * only enable fscache for reads * may not be the best approach (see future patcheset items below) 2. Basically works and passes a series of tests * should not affect NFS when fscache is disabled (no "fsc" option) * a couple small NFS + fscache basic verification tests * connectathon (all NFS versions, with/without 'fsc' option) * various iozone tests (all NFS versions, with/without 'fsc' option) 3. Still has a few known problems that are being tracked down * Data integrity issue when write with O_DIRECT and read back without O_DIRECT (we get 0's back from the cache) * iozone tests run through ok but at the end superblock cookies are left (each NFS version has a different superblock cookie); this leads to "duplicate cookie" messages upon subsequent mounts / runs * A couple oopses in fscache reported to dhowells, may be related to NFS's enable/disable of fscache on read/write * Kernel build fails about halfway through with a strange dubious error at the same place, linking this file: ld: net/sunrpc/auth_gss/trace.o: attempt to load strings from a non-string section (number 41) In addition to fixing various code issues and above issues, a future patchset may: 1. The readpage/readpages conversion patch call read_helpers directly rather than isolation into fs/nfs/fscache.c * Similar to the AFS conversion, with calls directly to the read_helpers, but not sure about non-fsc code path 2. Add write-through support * Would probably eliminate some problematic code paths where fscache is turned on / off depending on whether a file switches from read to write and vice-versa * This would rework open as well * Have to work out whether this is possible or not and with what caveats as far as NFS version support (is this an NFSv4.x only thing?) 3. Rework dfprintks and/or add ftrace points * fscache/cachefiles has 'debug' logging similar to rpcdebug so not sure if we keep rpcdebug here or go full ftrace Dave Wysochanski (13): NFS: Clean up nfs_readpage() and nfs_readpages() NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read succeeds NFS: Refactor nfs_readpage() and nfs_readpage_async() to use nfs_readdesc NFS: Call readpage_async_filler() from nfs_readpage_async() NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async() NFS: Rename readpage_async_filler() to nfs_pageio_add_page_read() NFS: Convert fscache_acquire_cookie and fscache_relinquish_cookie NFS: Allow nfs_async_read_completion_ops to be used by other NFS code NFS: Convert nfs_readpage() and readpages() to new fscache API NFS: Allow NFS use of new fscache API in build NFS: Only use and unuse an fscache cookie a single time based on NFS_INO_FSCACHE NFS: Convert fscache invalidation and update aux_data and i_size NFS: Call nfs_fscache_invalidate() when write extends the size of the file fs/nfs/Kconfig | 2 +- fs/nfs/file.c | 20 +-- fs/nfs/fscache-index.c | 94 -------------- fs/nfs/fscache.c | 315 ++++++++++++++++++++++++----------------------- fs/nfs/fscache.h | 92 +++++--------- fs/nfs/inode.c | 1 - fs/nfs/internal.h | 4 + fs/nfs/pagelist.c | 1 + fs/nfs/read.c | 221 ++++++++++++++++----------------- fs/nfs/write.c | 9 +- include/linux/nfs_fs.h | 3 +- include/linux/nfs_page.h | 1 + include/linux/nfs_xdr.h | 1 + 13 files changed, 322 insertions(+), 442 deletions(-)