From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967057AbaFQWaS (ORCPT ); Tue, 17 Jun 2014 18:30:18 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54201 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966395AbaFQVtd (ORCPT ); Tue, 17 Jun 2014 17:49:33 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Rusty Russell , Kamal Mostafa Subject: [PATCH 3.13 180/212] virtio_blk: don't crash, report error if virtqueue is broken. Date: Tue, 17 Jun 2014 14:44:34 -0700 Message-Id: <1403041506-13646-181-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403041506-13646-1-git-send-email-kamal@canonical.com> References: <1403041506-13646-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Rusty Russell commit 5261b85e586afe6ebe54e16e0a8acc32fc6d4902 upstream. A bad implementation of virtio might cause us to mark the virtqueue broken: we'll dev_err() in that case, and the device is useless, but let's not BUG_ON(). ENOMEM or ENOSPC implies the ring is full, and we should try again later (-ENOMEM is documented to happen, but doesn't, as we fall through to ENOSPC). EIO means it's broken. Signed-off-by: Rusty Russell Signed-off-by: Kamal Mostafa --- drivers/block/virtio_blk.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 6a680d4..704d6c8 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -158,6 +158,7 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) unsigned long flags; unsigned int num; const bool last = (req->cmd_flags & REQ_END) != 0; + int err; BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); @@ -198,11 +199,16 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) } spin_lock_irqsave(&vblk->vq_lock, flags); - if (__virtblk_add_req(vblk->vq, vbr, vbr->sg, num) < 0) { + err = __virtblk_add_req(vblk->vq, vbr, vbr->sg, num); + if (err) { virtqueue_kick(vblk->vq); spin_unlock_irqrestore(&vblk->vq_lock, flags); blk_mq_stop_hw_queue(hctx); - return BLK_MQ_RQ_QUEUE_BUSY; + /* Out of mem doesn't actually happen, since we fall back + * to direct descriptors */ + if (err == -ENOMEM || err == -ENOSPC) + return BLK_MQ_RQ_QUEUE_BUSY; + return BLK_MQ_RQ_QUEUE_ERROR; } if (last) -- 1.9.1