[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2] xen_disk: fix io accounting
From: |
Stefano Stabellini |
Subject: |
Re: [Qemu-devel] [PATCH v2] xen_disk: fix io accounting |
Date: |
Fri, 7 Feb 2014 14:57:31 +0000 |
User-agent: |
Alpine 2.02 (DEB 1266 2009-07-14) |
On Fri, 7 Feb 2014, Olaf Hering wrote:
> bdrv_acct_done was called unconditional. But in case the ioreq has no
> segments there is no matching bdrv_acct_start call. This could lead to
> bogus accounting values.
>
> Found by code inspection.
>
> Signed-off-by: Olaf Hering <address@hidden>
added to my queue, I'll fix the tab manually
> v2:
> add comment /* fall through */
>
> hw/block/xen_disk.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
> index 098f6c6..fb4ca4a 100644
> --- a/hw/block/xen_disk.c
> +++ b/hw/block/xen_disk.c
> @@ -483,7 +483,19 @@ static void qemu_aio_complete(void *opaque, int ret)
> ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY;
> ioreq_unmap(ioreq);
> ioreq_finish(ioreq);
> - bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct);
> + switch (ioreq->req.operation) {
> + case BLKIF_OP_WRITE:
> + case BLKIF_OP_FLUSH_DISKCACHE:
> + if (!ioreq->req.nr_segments) {
> + break;
> + }
> + /* fall through */
> + case BLKIF_OP_READ:
> + bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct);
> + break;
> + default:
> + break;
> + }
> qemu_bh_schedule(ioreq->blkdev->bh);
> }
>
>