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 8B14A32B994 for ; Thu, 26 Feb 2026 21:20:04 +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=1772140804; cv=none; b=CMbQ7usht27BX0erygb3feWmJemT1m8ryh+aXnN8mWLjr2isIZkDIKgpddPgW5S0kpsfgWIfuf19cu6rI6oIARoXrjkcQFTC1SwX/G17xpQHuA44a1Ff73+qFE0KCmMfp4kn9GGD+DvnMYXGxoAjJNfBjL/9hJ8JHZXCwyazzlg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772140804; c=relaxed/simple; bh=LcL/r6T0bwMo65lkXjTX40Fej57IPijPz0S5OcvY14A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CQzWb8jIBJSA8bC2cnDsqXAIhE2WBK5cod92zruS86spQSq5ZE1hi5cQRladUjj0zcJ572JfDLteWeE7rgjGf2LTpKOVSF2scKYerRpoRxfW25E663jbR4qzpGbmhm6RMdn1Z6P1mL/cDKNlZZgrDEFGLZcADU4EQJBRb0VdxSs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pcbecYNx; 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="pcbecYNx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB8B8C116C6; Thu, 26 Feb 2026 21:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772140804; bh=LcL/r6T0bwMo65lkXjTX40Fej57IPijPz0S5OcvY14A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pcbecYNxyD0Arty+tjaqDKnyQYiFGrH+9d7j3f1EcmyVIxuEVg/qOGLQSs7KCwf4h yfu4H2IZT/tx8LGFZAbBMMydQCW4DqGd7pamXr2AssEsiT+Lputy0Er8VWBWy0XdE4 SZgkXwjbXrdpQ+8YJ5beTsTBsSdT5cPbw+p8YD86om+FP2vjccOCW8T1mQsDc6oRad qsXWL1tw8eB/60peuIvDVsxPGdpDHFEd7vMsYtKpTFM8UZMVEZ0LNs15OTSmqDaF70 6w871y3QEgmKvq+H5EsNTHFkP+dmheB3iSicMfZe4w7r69jnh5TtP26Mg0C2zEcUw3 gWoaSzSqSUfag== Date: Thu, 26 Feb 2026 14:20:02 -0700 From: Keith Busch To: Caleb Sander Mateos Cc: Jens Axboe , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 6/8] nvme: set discard_granularity from NPDG/NPDA Message-ID: References: <20260226190416.297725-1-csander@purestorage.com> <20260226190416.297725-7-csander@purestorage.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260226190416.297725-7-csander@purestorage.com> On Thu, Feb 26, 2026 at 12:04:13PM -0700, Caleb Sander Mateos wrote: > + if (optperf & 0x2 && nvm && nvm->npdgl) > + npdg = le32_to_cpu(nvm->npdgl); > + else if (optperf & 0x1) > + npdg = from0based(id->npdg); > + if (optperf & 0x2 && nvm && nvm->npdal) > + npda = le32_to_cpu(nvm->npdal); > + else if (optperf) > + npda = from0based(id->npda); > + lim->discard_granularity = max(npdg, npda) * lim->logical_block_size; I suspect some controller could report a very large npdal/npdgl such that the multiplication result overflows the discard_granularity type, so let's check with a fallback: if (check_mul_overflow(max(npdg, npda), lim->logical_block_size, &result)) lim->discard_granularity = U32_MAX & (lim->logical_block_size - 1);