From patchwork Wed May 4 13:21:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Wysochanski X-Patchwork-Id: 12837942 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 5B25FC433F5 for ; Wed, 4 May 2022 13:22:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350654AbiEDN0G (ORCPT ); Wed, 4 May 2022 09:26:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350646AbiEDNZh (ORCPT ); Wed, 4 May 2022 09:25:37 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BF1C944769 for ; Wed, 4 May 2022 06:21:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651670472; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Qe4yVAvzQpTnaqUWjZUA3f+aoL1YlAlWs24T4YHjd4M=; b=CgQ2E7Dm2zy6yXW5oxb7C4pBd3pJ4GfcSIokfxC121/ZcsNPGjofLQDLgE1m8Mm1ez8OVW FWxZaN8BGveJfMA0iGXNWdWO9qDDlNuOS9pfG5O1A1jVFL1dAgJ6Bp8otF2NhOJno+0JSq tTYfQthFt5v/9Jyrm7CgKhOKWQzCoe8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-218-EKKuowZ6PWWny_NHZe8fbw-1; Wed, 04 May 2022 09:21:09 -0400 X-MC-Unique: EKKuowZ6PWWny_NHZe8fbw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C4440899ED3; Wed, 4 May 2022 13:21:08 +0000 (UTC) Received: from dwysocha.rdu.csb (unknown [10.22.9.36]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 82A86155BC8B; Wed, 4 May 2022 13:21:08 +0000 (UTC) From: Dave Wysochanski To: Anna Schumaker , Trond Myklebust Cc: linux-nfs@vger.kernel.org, linux-cachefs@redhat.com, David Howells , Daire Byrne Subject: [PATCH] NFS: Pass i_size to fscache_unuse_cookie() when a file is released Date: Wed, 4 May 2022 09:21:06 -0400 Message-Id: <20220504132106.28812-1-dwysocha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Pass updated i_size in fscache_unuse_cookie() when called from nfs_fscache_release_file(), which ensures the size of an fscache object gets written to the cache storage. Failing to do so results in unnessary reads from the NFS server, even when the data is cached, due to a cachefiles object coherency check failing with a trace similar to the following: cachefiles_coherency: o=0000000e BAD osiz B=afbb3 c=0 This problem can be reproduced as follows: #!/bin/bash v=4.2; NFS_SERVER=127.0.0.1 set -e; trap cleanup EXIT; rc=1 function cleanup { umount /mnt/nfs > /dev/null 2>&1 RC_STR="TEST PASS" [ $rc -eq 1 ] && RC_STR="TEST FAIL" echo "$RC_STR on $(uname -r) with NFSv$v and server $NFS_SERVER" } mount -o vers=$v,fsc $NFS_SERVER:/export /mnt/nfs rm -f /mnt/nfs/file1.bin > /dev/null 2>&1 dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1 > /dev/null 2>&1 echo 3 > /proc/sys/vm/drop_caches echo Read file 1st time from NFS server into fscache dd if=/mnt/nfs/file1.bin of=/dev/null > /dev/null 2>&1 umount /mnt/nfs && mount -o vers=$v,fsc $NFS_SERVER:/export /mnt/nfs echo 3 > /proc/sys/vm/drop_caches echo Read file 2nd time from fscache dd if=/mnt/nfs/file1.bin of=/dev/null > /dev/null 2>&1 echo Check mountstats for NFS read grep -q "READ: 0" /proc/self/mountstats # (1st number) == 0 [ $? -eq 0 ] && rc=0 Fixes: a6b5a28eb56c "nfs: Convert to new fscache volume/cookie API" Signed-off-by: Dave Wysochanski Tested-by: Daire Byrne --- fs/nfs/fscache.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c index f73c09a9cf0a..e861d7bae305 100644 --- a/fs/nfs/fscache.c +++ b/fs/nfs/fscache.c @@ -231,11 +231,10 @@ void nfs_fscache_release_file(struct inode *inode, struct file *filp) { struct nfs_fscache_inode_auxdata auxdata; struct fscache_cookie *cookie = nfs_i_fscache(inode); + loff_t i_size = i_size_read(inode); - if (fscache_cookie_valid(cookie)) { - nfs_fscache_update_auxdata(&auxdata, inode); - fscache_unuse_cookie(cookie, &auxdata, NULL); - } + nfs_fscache_update_auxdata(&auxdata, inode); + fscache_unuse_cookie(cookie, &auxdata, &i_size); } /*