From patchwork Wed Apr 14 13:43:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 12202877 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 BAEE0C43470 for ; Wed, 14 Apr 2021 13:44:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CF9F611B0 for ; Wed, 14 Apr 2021 13:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243282AbhDNNog (ORCPT ); Wed, 14 Apr 2021 09:44:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:52142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351583AbhDNNoQ (ORCPT ); Wed, 14 Apr 2021 09:44:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 743B3611AD for ; Wed, 14 Apr 2021 13:43:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618407835; bh=Av2mTAvTPBRR6n/iApvQ7Kz11QtjqJfgvAB+6CQmYVc=; h=From:To:Subject:Date:In-Reply-To:References:From; b=TjuBtKfF6UZmeYec22E+IRiwo+tLTZ4bHY1yZU81S/+aCdHSUb5GF3JfUPA4w9eri ljX+72EAmyyZpUPfBSn68Vx9Milia8afMA9tRGzOeh77nqYNDNEFYgREu6JThvxnYj WTV+3g+v5C3n6j1TbVVX6i+ATSfbM0gurQ6e6fwHcolrzRbS7vVKiNU+obtrL+uGvi LD3TIuZ3IukTvrvfh7orRzf/HBet5pECzJdkn+VhjnLMQpv2U12NjcEHS0Sm+4Dyj1 D1OvtSRxywDeR/pl6C29zfROUj1KbP46QwhXChK8x/nrQVFlK+ByrNMfFC+ro+IHVg bg6d9kZB3tYWA== From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH v2 01/26] NFS: Deal correctly with attribute generation counter overflow Date: Wed, 14 Apr 2021 09:43:28 -0400 Message-Id: <20210414134353.11860-2-trondmy@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210414134353.11860-1-trondmy@kernel.org> References: <20210414134353.11860-1-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust We need to use unsigned long subtraction and then convert to signed in order to deal correcly with C overflow rules. Fixes: f5062003465c ("NFS: Set an attribute barrier on all updates") Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index ff737be559dc..8de5b3b9da91 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1662,10 +1662,10 @@ EXPORT_SYMBOL_GPL(_nfs_display_fhandle); */ static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr) { - const struct nfs_inode *nfsi = NFS_I(inode); + unsigned long attr_gencount = NFS_I(inode)->attr_gencount; - return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 || - ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0); + return (long)(fattr->gencount - attr_gencount) > 0 || + (long)(attr_gencount - nfs_read_attr_generation_counter()) > 0; } static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) @@ -2094,7 +2094,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) nfsi->attrtimeo_timestamp = now; } /* Set the barrier to be more recent than this fattr */ - if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0) + if ((long)(fattr->gencount - nfsi->attr_gencount) > 0) nfsi->attr_gencount = fattr->gencount; }