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=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 56838C63777 for ; Mon, 30 Nov 2020 19:47:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E091A2063A for ; Mon, 30 Nov 2020 19:47:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fieldses.org header.i=@fieldses.org header.b="Kc5jp8hb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728013AbgK3Trg (ORCPT ); Mon, 30 Nov 2020 14:47:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726769AbgK3Trg (ORCPT ); Mon, 30 Nov 2020 14:47:36 -0500 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04237C0613D2 for ; Mon, 30 Nov 2020 11:46:56 -0800 (PST) Received: by fieldses.org (Postfix, from userid 2815) id 5C0336F4A; Mon, 30 Nov 2020 14:46:55 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 5C0336F4A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1606765615; bh=TGlVQ/ct8vGupystHx32X+YyTSvufqqKSPrKF5Y2qO0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Kc5jp8hbritEmhoZXatKV0j7KoJz2/CF7eas0pb62fJDU4NuhqBMuYTnNaKln/grm CJgHkuvGF49mm5Z3egTknzb4kuwi3zQsOLVSdll1ukDzcRVQqCfjt1BbIDTozzWdXd I75gKQtr7wmEgT8liomCeuCHzN/bgfSlGTeOnkRE= Date: Mon, 30 Nov 2020 14:46:55 -0500 From: "J. Bruce Fields" To: Chuck Lever Cc: linux-nfs@vger.kernel.org, "J. Bruce Fields" Subject: Re: [PATCH 1/5] nfsd: only call inode_query_iversion in the I_VERSION case Message-ID: <20201130194655.GA17322@fieldses.org> References: <1606765137-17257-1-git-send-email-bfields@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1606765137-17257-1-git-send-email-bfields@fieldses.org> User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org This patch fixes the bug Daire saw. The rest is a replacement for the series I sent before, except that I haven't included the last few patches, which will need review from other filesystem people. --b. On Mon, Nov 30, 2020 at 02:38:53PM -0500, J. Bruce Fields wrote: > From: "J. Bruce Fields" > > inode_query_iversion() can modify i_version. Depending on the exported > filesystem, that may not be safe. For example, if you're re-exporting > NFS, NFS stores the server's change attribute in i_version and does not > expect it to be modified locally. This has been observed causing > unnecessary cache invalidations. > > The way a filesystem indicates that it's OK to call > inode_query_iverson() is by setting SB_I_VERSION. > > So, move the I_VERSION check out of encode_change(), where it's used > only in FATTR responses, to nfsd4_changeattr(), which is also called for > pre- and post- operation attributes. > > (Note we could also pull the NFSEXP_V4ROOT case into > nfsd4_change_attribute as well. That would actually be a no-op, since > pre/post attrs are only used for metadata-modifying operations, and > V4ROOT exports are read-only. But we might make the change in the > future just for simplicity.) > > Reported-by: Daire Byrne > Signed-off-by: J. Bruce Fields > --- > fs/nfsd/nfs3xdr.c | 5 ++--- > fs/nfsd/nfs4xdr.c | 6 +----- > fs/nfsd/nfsfh.h | 14 ++++++++++---- > 3 files changed, 13 insertions(+), 12 deletions(-) > > diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c > index 2277f83da250..dfbf390ff40c 100644 > --- a/fs/nfsd/nfs3xdr.c > +++ b/fs/nfsd/nfs3xdr.c > @@ -291,14 +291,13 @@ void fill_post_wcc(struct svc_fh *fhp) > printk("nfsd: inode locked twice during operation.\n"); > > err = fh_getattr(fhp, &fhp->fh_post_attr); > - fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr, > - d_inode(fhp->fh_dentry)); > if (err) { > fhp->fh_post_saved = false; > - /* Grab the ctime anyway - set_change_info might use it */ > fhp->fh_post_attr.ctime = d_inode(fhp->fh_dentry)->i_ctime; > } else > fhp->fh_post_saved = true; > + fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr, > + d_inode(fhp->fh_dentry)); > } > > /* > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > index 833a2c64dfe8..56fd5f6d5c44 100644 > --- a/fs/nfsd/nfs4xdr.c > +++ b/fs/nfsd/nfs4xdr.c > @@ -2298,12 +2298,8 @@ static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode, > if (exp->ex_flags & NFSEXP_V4ROOT) { > *p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time)); > *p++ = 0; > - } else if (IS_I_VERSION(inode)) { > + } else > p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode)); > - } else { > - *p++ = cpu_to_be32(stat->ctime.tv_sec); > - *p++ = cpu_to_be32(stat->ctime.tv_nsec); > - } > return p; > } > > diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h > index 56cfbc361561..3faf5974fa4e 100644 > --- a/fs/nfsd/nfsfh.h > +++ b/fs/nfsd/nfsfh.h > @@ -261,10 +261,16 @@ static inline u64 nfsd4_change_attribute(struct kstat *stat, > { > u64 chattr; > > - chattr = stat->ctime.tv_sec; > - chattr <<= 30; > - chattr += stat->ctime.tv_nsec; > - chattr += inode_query_iversion(inode); > + if (IS_I_VERSION(inode)) { > + chattr = stat->ctime.tv_sec; > + chattr <<= 30; > + chattr += stat->ctime.tv_nsec; > + chattr += inode_query_iversion(inode); > + } else { > + chattr = cpu_to_be32(stat->ctime.tv_sec); > + chattr <<= 32; > + chattr += cpu_to_be32(stat->ctime.tv_nsec); > + } > return chattr; > } > > -- > 2.28.0