From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BC80535FF68 for ; Tue, 16 Dec 2025 15:59:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765900742; cv=none; b=hFUHSYGxJFdu3Hxyo2xcjL5fNCFnLSz205ydUGlA2iaTCcd1rq7MWOXy3glVRlvipBhAl1L5NKSRjFnCc/uzf3puTt9hDW/BkzfvB8k1fe6H/CaW/lJP+ImEQgEv2eWkmyRJcba/anLc+OCUKLjXYrcoIftxASr09UTavKKK5us= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765900742; c=relaxed/simple; bh=ZMi3spAiKyJlSM4q6JLNsf9baRJRTntfWd+OaPTKOsY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NTQw3a6qWwC2ndi+IYtDqdx/VuldeDE2eHsI5aCn5ofpCW39lOXi1jQKZYGx1w4fsHF5jhYQGw/kOK6gW2JtTM2d1FuniRMhbbbIvW0k/+8tT6R4Uhx/zfUs/6uBz8FcjKXcouUfHnIoh9lzVN7YZ2yJRCY12A4uI2pKcOOI2P8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oYaAnyni; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oYaAnyni" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4015CC113D0; Tue, 16 Dec 2025 15:59:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765900741; bh=ZMi3spAiKyJlSM4q6JLNsf9baRJRTntfWd+OaPTKOsY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oYaAnyniaiqsMfMCPeBAxONcOlrCDBtCNYcCaBn/z69Fd+t8wwLVyvIsw+hZs+TBp jrGl74nJeFFyREz28MurBk7y0DcyYphKqqNLofFJqVCufFC6sxIygngOPJfrLBxXNT led1TXTnPUU0l6eIQLQeZ1LHzQtajRguJO8BaCF6+6vaUgGdEVm8zDYRn32nI+fTcE v+bnTjcKBn70lCY7GVYtGhIItSzTQmNNJ18FwLzcJWkUbPCIFhQFqcn+FODNdn4cPG PzmytwBO2DPr8jeozylNHc5Khg5kcrXwAUklhogmspCim1FNt9OE/tQmdBdXMyzhBJ +ST5pxbhSb63g== Date: Tue, 16 Dec 2025 07:59:00 -0800 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Carlos Maiolino , linux-xfs@vger.kernel.org Subject: Re: [PATCH 1/2] xfs: validate that zoned RT devices are zone aligned Message-ID: <20251216155900.GQ7725@frogsfrogsfrogs> References: <20251215094843.537721-1-hch@lst.de> <20251215094843.537721-2-hch@lst.de> <20251215191506.GI7725@frogsfrogsfrogs> <20251216051002.GA26237@lst.de> 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: <20251216051002.GA26237@lst.de> On Tue, Dec 16, 2025 at 06:10:02AM +0100, Christoph Hellwig wrote: > On Mon, Dec 15, 2025 at 11:15:06AM -0800, Darrick J. Wong wrote: > > > + if (xfs_sb_is_v5(sbp) && > > > + (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED)) { > > > + uint32_t mod; > > > + > > > + /* > > > + * Zoned RT devices must be aligned to the rtgroup size, because > > > + * garbage collection can't deal with rump RT groups. > > > > I've decided that I'm ok with imposing this new restriction after the > > fact, but only because actual zoned hardware will never expose a runt > > group, so the only way you could end up with one now is if you formatted > > with zoned=1 without a hardware-zoned storage device. > > > > Could this comment be expanded to say that explicitly? > > That comment would not actually be true. The hardware specs do allow > for runt zones. Bah. That figures. :( > No shipping hardware that I know of does that, and > mkfs protects against it, but the statement would be at best misleading > if not outright wrong. The real reason why this is fine is because > mkfs rounds the capacity down to the zone size. "...garbage collection won't deal with rump RT groups because the size increase isn't worth the corner case complexity.", then? :D --D