Re: [PATCH v3 1/2] hw/nvme: fix incorrect use of errp/local_err

[Markus Armbruster]

Klaus Jensen <its@irrelevant.dk> writes:

> From: Klaus Jensen <k.jensen@samsung.com>
>
> Remove an unnecessary local Error value in nvme_realize(). In the
> process, change nvme_check_constraints() into returning a bool.
>
> Finally, removing the local Error value also fixes a bug where an error
> returned from nvme_init_subsys() would be lost.

Would it be lost?  It's the hunk below:

> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> ---
>  hw/nvme/ctrl.c | 48 +++++++++++++++++++++++-------------------------
>  1 file changed, 23 insertions(+), 25 deletions(-)
>
> diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
> index ac3885ce5079..a5c0a5fa6ce2 100644
> --- a/hw/nvme/ctrl.c
> +++ b/hw/nvme/ctrl.c

[...]

> @@ -7586,7 +7585,6 @@ static void nvme_realize(PCIDevice *pci_dev, Error 
> **errp)
   static void nvme_realize(PCIDevice *pci_dev, Error **errp)
   {
       NvmeCtrl *n = NVME(pci_dev);
       NvmeNamespace *ns;
       Error *local_err = NULL;

@local_err is null.

       NvmeCtrl *pn = NVME(pcie_sriov_get_pf(pci_dev));

       if (pci_is_vf(pci_dev)) {
           /*
            * VFs derive settings from the parent. PF's lifespan exceeds
            * that of VF's, so it's safe to share params.serial.
            */
           memcpy(&n->params, &pn->params, sizeof(NvmeParams));
           n->subsys = pn->subsys;
       }

       nvme_check_constraints(n, &local_err);
       if (local_err) {
           error_propagate(errp, local_err);
           return;
       }

@local_err still is null.

       qbus_init(&n->bus, sizeof(NvmeBus), TYPE_NVME_BUS,
>                &pci_dev->qdev, n->parent_obj.qdev.id);
>  
>      if (nvme_init_subsys(n, errp)) {
> -        error_propagate(errp, local_err);

Since @local_err is null, this error_propagate() does nothing.  The
error from nvme_init_subsys() remains in @errp.

>          return;
>      }
>      nvme_init_state(n);