From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C87BB3587CA for ; Mon, 22 Dec 2025 22:35:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766442914; cv=none; b=QscCdXVDFTauITpb/xpm6kIQ24e9kaMMYiSm+NBAKK25/FePNgv1IqAqiti1jR/LwZfn0wW353WUFGBAkd617sT5eM2nATwKTbvUtpqvoN8SQSeg37obYvDz4+IsetrRINKbaWqPovmhkUGMAUY/yNB5PJVoLEMbtBeDh5+T8/k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766442914; c=relaxed/simple; bh=E3Vr2+Zgze96dVifQsc2fJgv3ODt24/Mo/PpbehLnhU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GOWcbfdKlc6AYrN9dLVHic7u9pEAkPAhwiD0qp+czae1+bCjc05rjETy/8VnSNckiuywnElKDKT04o9NmuNymW9K1cVJqe710I9qVV5SoJBjF5NwIG6wf6uYqzgUMMuhBYcX2kFN+Urug27ImxZq4bEE/q4ieMKXAmxZ/D7nN3Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=T5UuKufk; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="T5UuKufk" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=XCupXeMpfsW3ocP0dcMZe871ZtNsLRnhJGR8PQaw+GI=; b=T5UuKufkOIZ/ZzHvNlxRDLlPhM Lhwvif4YUhsF85e3pyRgNETwgsJkkeAQngH+BqwKW6fzwYA0Jc4Vc3zcsKc7ILvpU9qv22KjqSx6i n6gSaF0sFOKeyZLexvemRhF+jEP0gDrlOP1WmpKbuGEcJOnoVaaYnxhBe31L6/oF+7nzErJAtOaWI uFDyNcgMtw8hBqHL2hpmd62ifLuwqViuzwPRfYj+DOUsKcqNYM8EyHpw8/jfjAhDZOaYeaIrwRQbV zv4fAO0hmcdA2FjM+Dwvz+v+HaQw3khP3V0vCmlQ5p03GUI7TzSx95YikZyXUxzFnwMWq+T7m/W59 tM0CZvqw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vXoUg-0000000EESS-3xzm; Mon, 22 Dec 2025 22:35:10 +0000 Date: Mon, 22 Dec 2025 14:35:10 -0800 From: Christoph Hellwig To: Anna Schumaker Cc: linux-nfs@vger.kernel.org, trond.myklebust@hammerspace.com Subject: Re: [PATCH] NFS: Fix directory delegation verifier checks Message-ID: References: <20251219201344.380279-1-anna@kernel.org> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251219201344.380279-1-anna@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Dec 19, 2025 at 03:13:44PM -0500, Anna Schumaker wrote: > From: Anna Schumaker > > Doing this check in nfs_check_verifier() resulted in many, many more > lookups on the wire when running Christoph's delegation benchmarking > script. After some experimentation, I found that we can treat directory > delegations exactly the same as having a delegated verifier when we > reach nfs4_lookup_revalidate() for the best performance. > > Reported-by: Christoph Hellwig > Fixes: 156b09482933 ("NFS: Request a directory delegation on ACCESS, CREATE, and UNLINK") > Signed-off-by: Anna Schumaker I wish I could actually review this, but I don't actually understand the lookup revalidation logic enough for that. But it does fix the problem I saw, so at least: Tested-by: Christoph Hellwig