Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752903AbdHDNYs (ORCPT ); Fri, 4 Aug 2017 09:24:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52656 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752326AbdHDNYp (ORCPT ); Fri, 4 Aug 2017 09:24:45 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7FD498124F Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=mst@redhat.com Date: Fri, 4 Aug 2017 16:24:36 +0300 From: "Michael S. Tsirkin" To: Stefan Hajnoczi Cc: linux-kernel@vger.kernel.org, Jason Wang , virtualization@lists.linux-foundation.org Subject: Re: [PATCH] virtio_blk: fix incorrect message when disk is resized Message-ID: <20170804162420-mutt-send-email-mst@kernel.org> References: <20170726143223.2769-1-stefanha@redhat.com> <20170804093754.GA9867@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170804093754.GA9867@stefanha-x1.localdomain> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 04 Aug 2017 13:24:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2731 Lines: 72 On Fri, Aug 04, 2017 at 10:37:54AM +0100, Stefan Hajnoczi wrote: > On Wed, Jul 26, 2017 at 03:32:23PM +0100, Stefan Hajnoczi wrote: > > The message printed on disk resize is incorrect. The following is > > printed when resizing to 2 GiB: > > > > $ truncate -s 1G test.img > > $ qemu -device virtio-blk-pci,logical_block_size=4096,... > > (qemu) block_resize drive1 2G > > > > virtio_blk virtio0: new size: 4194304 4096-byte logical blocks (17.2 GB/16.0 GiB) > > > > The virtio_blk capacity config field is in 512-byte sector units > > regardless of logical_block_size as per the VIRTIO specification. > > Therefore the message should read: > > > > virtio_blk virtio0: new size: 524288 4096-byte logical blocks (2.15 GB/2.0 GiB) > > > > Note that this only affects the printed message. Thankfully the actual > > block device has the correct size because the block layer expects > > capacity in sectors. > > > > Signed-off-by: Stefan Hajnoczi > > --- > > drivers/block/virtio_blk.c | 16 ++++++++++------ > > 1 file changed, 10 insertions(+), 6 deletions(-) > > Ping? Oops - I thought I sent it up. Will do. > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > index 4e02aa5fdac0..69a2d1748743 100644 > > --- a/drivers/block/virtio_blk.c > > +++ b/drivers/block/virtio_blk.c > > @@ -381,6 +381,7 @@ static void virtblk_config_changed_work(struct work_struct *work) > > struct request_queue *q = vblk->disk->queue; > > char cap_str_2[10], cap_str_10[10]; > > char *envp[] = { "RESIZE=1", NULL }; > > + unsigned long long nblocks; > > u64 capacity; > > > > /* Host must always specify the capacity. */ > > @@ -393,16 +394,19 @@ static void virtblk_config_changed_work(struct work_struct *work) > > capacity = (sector_t)-1; > > } > > > > - string_get_size(capacity, queue_logical_block_size(q), > > + nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); > > + > > + string_get_size(nblocks, queue_logical_block_size(q), > > STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); > > - string_get_size(capacity, queue_logical_block_size(q), > > + string_get_size(nblocks, queue_logical_block_size(q), > > STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); > > > > dev_notice(&vdev->dev, > > - "new size: %llu %d-byte logical blocks (%s/%s)\n", > > - (unsigned long long)capacity, > > - queue_logical_block_size(q), > > - cap_str_10, cap_str_2); > > + "new size: %llu %d-byte logical blocks (%s/%s)\n", > > + nblocks, > > + queue_logical_block_size(q), > > + cap_str_10, > > + cap_str_2); > > > > set_capacity(vblk->disk, capacity); > > revalidate_disk(vblk->disk); > > -- > > 2.13.3 > >