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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B10AC18E5B for ; Tue, 17 Mar 2020 11:10:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73EFF206EC for ; Tue, 17 Mar 2020 11:10:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584443425; bh=PqWD8O81LYKtCIQk9TxWpkpd8TvOh8TUSwA3cRe6/Ek=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QYF/lL/W8caIGUgxgaYasXIBr3Y/Zu3YWGtJw0bUkRYIN01GAxDuTjQ3D9soWpYpU jtrL+fxXLuA/sSJAi8OrXT1Krl+S1MWsbuGRbQwoaWyML7kO2s+GUVzVmVgMglkcXf VeaclXHhDAS3VLaB6JrUGNADW/ROkhgNTK7nijnI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729083AbgCQLKX (ORCPT ); Tue, 17 Mar 2020 07:10:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:53118 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728745AbgCQLKU (ORCPT ); Tue, 17 Mar 2020 07:10:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8723B20714; Tue, 17 Mar 2020 11:10:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584443420; bh=PqWD8O81LYKtCIQk9TxWpkpd8TvOh8TUSwA3cRe6/Ek=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zi/jIPNRmxJyL8pDPnkG9l3Yi3bZOk9Dwi2GLZH4ptVPqRD2jtDuEBFQN5XRpEyyd s5tUGTTvN5YM+XSMXsTH7l6uaWxJWqL0G7Um9iiJL4ZKBxZ9fYl1PEAzYNZoUkyCoI nhwIYB56g5uXdp11xNysBBb2PSjqWTX1A7BEfLg8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Halil Pasic , Jens Axboe , "Michael S. Tsirkin" , Stefan Hajnoczi Subject: [PATCH 5.5 077/151] virtio-blk: fix hw_queue stopped on arbitrary error Date: Tue, 17 Mar 2020 11:54:47 +0100 Message-Id: <20200317103331.950977130@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200317103326.593639086@linuxfoundation.org> References: <20200317103326.593639086@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Halil Pasic commit f5f6b95c72f7f8bb46eace8c5306c752d0133daa upstream. Since nobody else is going to restart our hw_queue for us, the blk_mq_start_stopped_hw_queues() is in virtblk_done() is not sufficient necessarily sufficient to ensure that the queue will get started again. In case of global resource outage (-ENOMEM because mapping failure, because of swiotlb full) our virtqueue may be empty and we can get stuck with a stopped hw_queue. Let us not stop the queue on arbitrary errors, but only on -EONSPC which indicates a full virtqueue, where the hw_queue is guaranteed to get started by virtblk_done() before when it makes sense to carry on submitting requests. Let us also remove a stale comment. Signed-off-by: Halil Pasic Cc: Jens Axboe Fixes: f7728002c1c7 ("virtio_ring: fix return code on DMA mapping fails") Link: https://lore.kernel.org/r/20200213123728.61216-2-pasic@linux.ibm.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Signed-off-by: Greg Kroah-Hartman --- drivers/block/virtio_blk.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -339,10 +339,12 @@ static blk_status_t virtio_queue_rq(stru err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num); if (err) { virtqueue_kick(vblk->vqs[qid].vq); - blk_mq_stop_hw_queue(hctx); + /* Don't stop the queue if -ENOMEM: we may have failed to + * bounce the buffer due to global resource outage. + */ + if (err == -ENOSPC) + blk_mq_stop_hw_queue(hctx); spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); - /* Out of mem doesn't actually happen, since we fall back - * to direct descriptors */ if (err == -ENOMEM || err == -ENOSPC) return BLK_STS_DEV_RESOURCE; return BLK_STS_IOERR;