From patchwork Wed Mar 2 17:07:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 8483881 X-Patchwork-Delegate: axboe@kernel.dk Return-Path: X-Original-To: patchwork-linux-block@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 660409F314 for ; Wed, 2 Mar 2016 17:07:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CEEFA20148 for ; Wed, 2 Mar 2016 17:07:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D38B2022A for ; Wed, 2 Mar 2016 17:07:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752103AbcCBRHg (ORCPT ); Wed, 2 Mar 2016 12:07:36 -0500 Received: from casper.infradead.org ([85.118.1.10]:41141 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752268AbcCBRHf (ORCPT ); Wed, 2 Mar 2016 12:07:35 -0500 Received: from chello080109146114.tirol.surfer.at ([80.109.146.114] helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.85 #2 (Red Hat Linux)) id 1abAFF-0003dP-CL; Wed, 02 Mar 2016 17:07:29 +0000 From: Christoph Hellwig To: axboe@fb.com, keith.busch@intel.com Cc: Jeff.Lien@hgst.com, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org Subject: [PATCH 3/5] nvme: fix max_segments integer truncation Date: Wed, 2 Mar 2016 18:07:12 +0100 Message-Id: <1456938434-20387-4-git-send-email-hch@lst.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1456938434-20387-1-git-send-email-hch@lst.de> References: <1456938434-20387-1-git-send-email-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The block layer uses an unsigned short for max_segments. The way we calculate the value for NVMe tends to generate very large 32-bit values, which after integer truncation may lead to a zero value instead of the desired outcome. Signed-off-by: Christoph Hellwig Reported-by: Jeff Lien Tested-by: Jeff Lien Reviewed-by: Keith Busch --- drivers/nvme/host/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index cfee6ac..c30cb10 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -844,9 +844,11 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl, struct request_queue *q) { if (ctrl->max_hw_sectors) { + u32 max_segments = + (ctrl->max_hw_sectors / (ctrl->page_size >> 9)) + 1; + blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors); - blk_queue_max_segments(q, - (ctrl->max_hw_sectors / (ctrl->page_size >> 9)) + 1); + blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX)); } if (ctrl->stripe_size) blk_queue_chunk_sectors(q, ctrl->stripe_size >> 9);