Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752216AbaAOCmW (ORCPT ); Tue, 14 Jan 2014 21:42:22 -0500 Received: from ozlabs.org ([203.10.76.45]:55927 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752024AbaAOCmQ (ORCPT ); Tue, 14 Jan 2014 21:42:16 -0500 From: Rusty Russell To: linux-kernel@vger.kernel.org Cc: Heinz Graalfs , Rusty Russell Subject: [PATCH 2/6] virtio_blk: don't crash, report error if virtqueue is broken. Date: Wed, 15 Jan 2014 13:06:07 +1030 Message-Id: <1389753371-26469-2-git-send-email-rusty@rustcorp.com.au> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1389753371-26469-1-git-send-email-rusty@rustcorp.com.au> References: <1389753371-26469-1-git-send-email-rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 6a680d4de7f1..704d6c814c17 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) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/