From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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.lore.kernel.org (Postfix) with ESMTPS id 299EDFD9E0A for ; Thu, 26 Feb 2026 21:20:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=W8o1JNecTz/67qidTlo3xSpBMPNRej6TqsQ4eRKw7JE=; b=snW6sCY9ya42zXsynU2g+kgoif ZaimlJviH4CTqgqIlIP86aE221DvfbdDYM7copiZLAUN43QsI9cwHiV0z5bWwGrLW3t4cY8DWtI9H CAdh7XdZ+rYmvxmJKEgffMplWWVjXomF9NuWIbQmS7dWv7HGW/1MwkR5nd27oz9afxp1YAw6evUd6 Ri/28gr307Yk/OD1XK46G9t+9TK31ZNfUUiFLwzQUTIaP3EAKXpPZn4fAa9QlKbM3UgCOaNHZ5cJo N+vZjO0jYU9vg3ItMwnNpnj8VKDa86TzYu64J3Cx516nuQLkO8FtXs2bl2HUTkqIvjUAwOWqD5hl/ hj54RCcQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvimE-00000007EXE-14Y9; Thu, 26 Feb 2026 21:20:06 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvimD-00000007EWx-1Qlo for linux-nvme@lists.infradead.org; Thu, 26 Feb 2026 21:20:05 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 65BD0600AA; Thu, 26 Feb 2026 21:20:04 +0000 (UTC) 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260226190416.297725-7-csander@purestorage.com> X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org 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);