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 CC44818DF65; Thu, 10 Oct 2024 09:42:49 +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=1728553371; cv=none; b=c/EcSRGxizKvWOe2dBJw4I6mg5/gUJt/tHzKfmM/DY/5InEB7TqV/xBc+NbqoF4VUbEFw5Q6iOiK2mEx/OmN6i1TsR28H7czgqVnl9GeIdsdHLwINh0K2v+t2IpyGdhibFfwoby0XXZA+hRmkiqAIq+SPIEnlBP+sP01mJrq9eY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728553371; c=relaxed/simple; bh=346cdhzfMjk0IugSFuF5mu9ZT8QjdmGOPWqppdkR+Sw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=piimYImyqwgZK0wuQms629j/ud5Ww348Sv3UFRnr7hY+LXYXJOrgi+K4kBgX53qsnYx3NB3zSSX9/hpMPwjNry2YueX89OnarrBQAVoeSRg9MBCMB+9V2P3oZm4+G2z/6vCfRco1Ns7zuRDZs8VsN5dahRdp3iexG4F3CBm9J1w= 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=m4PK/UOx; 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="m4PK/UOx" 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=cRaxaOIG6VIWm/An1JMpyl8wdnm639NBZ/3o+pQVzBk=; b=m4PK/UOxubqShBQ4Rd0obSAgl9 eGhdntLwcUAmTGnXVwBpec+u5B/rbWNSQ4DjCiVicB6jaJfHRvkJZgkSs5zPLcbIO0CEpwZU4adty YDMgmv3hEWRis7PQ6qc+IsLim5gryqhjz/rU5IS3UmJr1iSpUB9CppG+v80vCan4CLxU7EmJZ3wvA eY18GLZPNnppJRdpfg3U5X546Xn8FT28IK1sfWhUgygLd/c/1Df7ib4VVCVjKPpmZUDKqx1+7TVVI MyzWdOhKhwvP0ORPqXRpqE7F7spFZuDm4ZOGUwZ94WfrT3YuC7sgYI+MHKCHLhNGIE8o5TC2+JRI2 X6+H0fUg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1syph3-0000000CGvD-1ino; Thu, 10 Oct 2024 09:42:49 +0000 Date: Thu, 10 Oct 2024 02:42:49 -0700 From: Christoph Hellwig To: Goldwyn Rodrigues Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Goldwyn Rodrigues , Ritesh Harjani Subject: Re: [PATCH 05/12] iomap: Introduce IOMAP_ENCODED Message-ID: References: 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 Tue, Oct 08, 2024 at 02:48:43AM -0700, Christoph Hellwig wrote: > In general I'm not a huge fan of the encoded magic here, but I'll > need to take a closer look at the caller if I can come up with > something better. I looked a bit more at the code. I'm not entirely sure I fully understand it yet, but: I think most of the read side special casing would be handled by always submitting the bio at the end of an iomap. Ritesh was looking into that for supporting ext2-like file systems that read indirect block ondemand, but I think it actually is fundamentally the right thing to do anyway. For the write we plan to add a new IOMAP_BOUNDARY flag to prevent merges as part of the XFS RT group series, and I think this should also solve your problems with keeping one bio per iomap? The current patch is here: https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/commit/?h=djwong-wtf&id=91b5d7a52dab63732aee451bba0db315ae9bd09b