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 EC2871DF748 for ; Mon, 31 Aug 2026 08:09:30 +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=1788163775; cv=none; b=IjH55WwGE7q8LwpbuI80PIRc+l0xzBTtIPmwauIwbzZEYOITF0GWIzI3g6o0p8v9wwqdrHmDdE0A2xWV6zi8mKpR1u7z5IwGpJUFh/lEH7XRQn6O2/eYra6s1oN40/Xw1QBN2kIWiF0ojh2saE3b0F5/0X2DO7YgRM2bYGOu6fU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788163775; c=relaxed/simple; bh=lVkFsjOkW0qG7+18JLOlFKPg3Xh5pBVcH4DIO7bj98s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=f/tX76Gj2H7ylQgwZKMMf4dxiwSZ2uGtA1HZFbtZ9K3S7xJYIXc/bA+w1LmC3aMIc45CTr6vWJYn7Uer976S8m2i9JuU3JwUnFJlyD0o6/hfZbL/AusELmeuZ0fZZtMJAH4+/nX8APeu2k7xcRK5kSRnQC1ZxGE8BaJ+PsOAzCQ= 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=2/qxgGOR; 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="2/qxgGOR" 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=avwCKTeRYR4TKhCvB/ogpAKBtyGQ0OHTaEVbI+FSorU=; b=2/qxgGORM96jrZrboL7KzMaHl/ vNJ9kUlDWZl9/yno9+Q3m78NkLPZTIiBQm+bJ4vxqw4RtTqMW0jtH6xg7OTn4zA07ycLkboszuLYQ ttYWGfNwuReckYRib476KkOmNHo/61uIA6kP0Q07f1H1XARSISptgu8IkjGia5jtWg9J9hVS/FaVW jEWdSonrkf5ik1g5tbQbAJdbUA+9x81Fm8Ob6CPccQrMe97qG+sYprAYqLB7+NebzVpdHMniKVimg TWbqjAIKrTEA8euVpYATx6IDLDD+O56brlEV05zt44xusSYTxplA++YBOg+WvotLHkhDA6PW9yRjB kNQSzEDw==; Received: from hch by bombadil.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1x0x58-00000008naF-1tu0; Mon, 31 Aug 2026 08:09:30 +0000 Date: Mon, 31 Aug 2026 01:09:30 -0700 From: Christoph Hellwig To: Qu Wenruo Cc: Christoph Hellwig , Qu Wenruo , linux-btrfs@vger.kernel.org Subject: Re: [PATCH] btrfs: use IOMAP_DIO_BOUNCE flag for direct reads Message-ID: References: <1219d8d9ed105a922d9af6130e08532e2907ea17.1787909265.git.wqu@suse.com> <74188ab7-96d7-4536-997f-926a5a845f79@gmx.com> Precedence: bulk X-Mailing-List: linux-btrfs@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: <74188ab7-96d7-4536-997f-926a5a845f79@gmx.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Aug 31, 2026 at 05:01:21PM +0930, Qu Wenruo wrote: > However it only shows up in lore, but not in my inbox at all, and I have no > idea why. > > And lore is never a good way to review patches, nor easy to reply. I got it brack through all the usual lists, so this must be some kind of filtering on your side. > > For one this removes the read-side IOMAP_DIO_BOUNCE support you are > > using here, because it had problems. The alternative is iomap-based > > and better at building large, aligned read bios which matter for HDD. > > It also introduces the concept of lazy bouncing where it only bounce > > buffers after a checksum failure happens by default, which means you > > only pay an overhead for misbehaving applications. > > In that case I'm afraid btrfs may need some way to integrate the checksum > handling into iomap. > As the btrfs has a very internal handling for repairing each block. The only iomap path is the bounce buffering, the checksum handling is still left to the file systems. The code will probably need some minor tweaks for btrfs, like passing in a bio_set to use for the clones, but it shouldn't be too bad.