Re: [Qemu-block] [PATCH] nvme: Make nvme_init error handling code more readable

[Paolo Bonzini]

On 21/05/2018 08:35, Fam Zheng wrote:
> Coverity doesn't like the tests under fail label (report CID 1385847).
> Reset the fields so the clean up order is more apparent.
> 
> Signed-off-by: Fam Zheng <address@hidden>
> ---
>  block/nvme.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/block/nvme.c b/block/nvme.c
> index 6f71122bf5..8239b920c8 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -560,6 +560,13 @@ static int nvme_init(BlockDriverState *bs, const char 
> *device, int namespace,
>      qemu_co_queue_init(&s->dma_flush_queue);
>      s->nsid = namespace;
>      s->aio_context = bdrv_get_aio_context(bs);
> +
> +    /* Fields we've not touched should be zero-initialized by block layer
> +     * already, but reset them anyway to make the error handling code easier 
> to
> +     * reason. */
> +    s->regs = NULL;
> +    s->vfio = NULL;
> +
>      ret = event_notifier_init(&s->irq_notifier, 0);
>      if (ret) {
>          error_setg(errp, "Failed to init event notifier");
> 

I think we should just mark it as a false positive or do something like

fail_regs:
    qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE);
fail_vfio:
    qemu_vfio_close(s->vfio);
fail:
    g_free(s->queues);
    event_notifier_cleanup(&s->irq_notifier);
    return ret;

even though it's a larger patch.

Paolo