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 C4B8A2AE8B; Mon, 25 Nov 2024 05:12:26 +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=1732511548; cv=none; b=V0QZxGKLdZBc/HNjsZoWdxIYAn+GNIHYSSFNQjwjn3eTtbECjJwtFARuZCkCEdqVVH7bcjrIHvLk5EkJR0MWMHSkiaI162Jqs2j3MIOfTuc/Xol9irS2cExc36X0GXK67KQgd/Yr28IZeSl9nTD869fgSPsysQQmNH1UhdL4p6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732511548; c=relaxed/simple; bh=0s2lUWMQKR0hoLosHCt0cYkCQuad1nAysL6sRmMAGMk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GGyl+rImDMch9XhQc96XmBPM1lrlUzNAxhQ763Py84AlqrxmEwChBfCxspfc0VZdAa1dHvkyzlg/vqrxn7WqNrKSDjR8PmXvAYU63Mib7kmMj4JUETGp/6MqRy713oMxRxRvLn7FnQambH0wYEZp3bYvvZEa8njFFnTc17R2x6E= 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=hyIXy+/A; 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="hyIXy+/A" 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=5+Be6KR913s2ZUa3ZM64I5ErQ55KrBwpt/vz1jRbqOc=; b=hyIXy+/AZZxQsBOV7WuDQ5pbvb mKSMaf6UvL5kSwQwNxN6kFthYNtel/qSyUsKepvPxvb+9V9IGxS0ynjdf5RLlsXIvs6c360liXN3R xjl8/pk72kheQZuUOG4oM6JmUb094BE5dfRPK9/o8U4bprIZRP6N6trfuaAHo6Yxj5OjKDguCGJaJ kCSAaLyYTECPhJ699B4Asz2rqG1qhJZNGFXGQF7VgFGEg1MIhWbljY0UYSMEh2a3Kpp1M6aCVy/aP I64AgrVNC/Mh+qkJvpC/zCki4q00O/mzemSKZp2xcR8e0nDRQFoihiFHVFFHbcZSMDCVxxNINwN92 +WDtLO9A==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tFROc-000000074bZ-0N4H; Mon, 25 Nov 2024 05:12:26 +0000 Date: Sun, 24 Nov 2024 21:12:26 -0800 From: Christoph Hellwig To: "Darrick J. Wong" Cc: zlang@redhat.com, fstests@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH 03/17] logwrites: warn if we don't think read after discard returns zeroes Message-ID: References: <173229419991.358248.8516467437316874374.stgit@frogsfrogsfrogs> <173229420060.358248.11054238752146807489.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@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: <173229420060.358248.11054238752146807489.stgit@frogsfrogsfrogs> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html This feels like it's heading in the wrong direction, as it just adds more hacks. IMHO the right thing is to: a) document current assumptions and tell users very clearly to use dm-thin to get the expected semantics b) if we have a use for it, provide an option to use write zeroes instead that can be used on any device I'm happy to do that work, but until then I'd suggest to skip this and the next two patches.