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 9118321883E; Tue, 10 Jun 2025 03:39:26 +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=1749526768; cv=none; b=hxTS295qtmF3yIIb+ZjbUTZ1Zo0xFR9XKKhOOlr/Rz768DBws6+WyvWJJsbakUtiE4Kba8ltCuOhcpS8xClD0g/QPcX8fxl8lxSU9r0Y+Ftib97UlC9ErRnV91jga0RZvOjyjoYxoQW5FgLDFTpFTYmL/s9FTFqgdwk/QU151XA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749526768; c=relaxed/simple; bh=WFlW/++qHGMPwJfahFxJu2UAhr+WVq1zZtHELuxTUb8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GRUB+guL/d98GjgcqrLDjrAMALxnRNuFmttZQZ+IklOlNzlADbi1uPbE+C5hLJEPa+E89y/1aQBIwLQiuv3ExtSSYRXj3woN5ZP3QsP/Sla49VfIRE7QflJdVTInna7IelAtrzZqu5LdW2sSA0T4Bycr2fzqYeD8uO6z8h1W3pg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=rvSCE2k8; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="rvSCE2k8" 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=GhStOomvkpU2vBUhXEJJZYGj7m3d8RJgB0w4RTLq+3s=; b=rvSCE2k83MoeULFUBgac25EBFZ IOhRpwLdC4unAgoYjuIoNvZqBF8s4WGQbARWf92lJFmZpqLjrGjNrRpRiJZGtzHeLhtyZjYPyyEDQ /7qhwrw6opuEfSoRibr+tLb4uhV4NzYBvmhGYMTD/zsVgdl1sq6Fu9CQLIyzNMn3ibmrFZbpVYH0g bJ9kB8ZM6q13mA1CB84TvKZ4fufc1q2gmTbyAaI96sb8uY/rbP7F+Av21/l3rv2UYQ4FN2wuWaSm+ Q/nzTSoI2QvS/W8EVCWENe8PheGmgDVc3DF2QApxnL/hsVk2UbOomSJebtEh/gj9xDDqkStSFLdzL 4L/9G1BA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uOppd-00000005h1E-3VVJ; Tue, 10 Jun 2025 03:39:25 +0000 Date: Mon, 9 Jun 2025 20:39:25 -0700 From: Christoph Hellwig To: Joanne Koong Cc: Christoph Hellwig , miklos@szeredi.hu, djwong@kernel.org, brauner@kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, bernd.schubert@fastmail.fm, kernel-team@meta.com Subject: Re: [PATCH v1 2/8] iomap: add IOMAP_IN_MEM iomap type Message-ID: References: <20250606233803.1421259-1-joannelkoong@gmail.com> <20250606233803.1421259-3-joannelkoong@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Jun 09, 2025 at 02:45:34PM -0700, Joanne Koong wrote: > IOMAP_INLINE is the closest in idea to what I'm looking for in that > it's completely independent from block io, but it falls short in a few > ways (described in the reply to Darrick in [1]). In terms of > implementation logic, IOMAP_MAPPED fits great but that's tied in idea > to mapped blocks and we'd be unable to make certain assertions (eg if > the iomap type doesn't use bios, the caller must provide > ->read_folio_sync() and ->writeback_folio() callbacks). Well, IFF we end up with both my proposals those two are the clean abstractions between the generic and block-level code and everyone is using them. Let's see how that plays out. I'd rather have a strong abstraction like that if we can and not add new types for what is essentially the same. Btw, for zoned XFS, IOMAP_MAPPED also doesn't have a block number assigned yet and only actually does the I/O in the submit_ioend method.