[dpdk-dev] [RFC V1] ethdev: fix the issue that dev uninit may be called twice

[Singh, Aman Deep]

Hi Huison,

On 8/2/2021 6:16 PM, Huisong Li wrote:
> Ethernet devices in DPDK can be released by rte_eth_dev_close() and
> rte_dev_remove(). However, these two APIs do not have explicit invocation
> restrictions. In other words, at the ethdev layer, calling
> rte_eth_dev_close() and then rte_dev_remove() or rte_eal_hotplug_remove()
> is allowed. In such a bad scenario, the primary process may be fine, but it
> may cause that dev_unint() in the secondary process will be called twice,

Shouldn't dev_unint() for Secondary process, simply return with no-action.

> and even other serious problems. So this patch fixes it.
>
> Fixes: 99a2dd955fba ("lib: remove librte_ prefix from directory names")
>
> Signed-off-by: Huisong Li <lihuisong at huawei.com>
> ---
>   lib/ethdev/ethdev_pci.h | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/lib/ethdev/ethdev_pci.h b/lib/ethdev/ethdev_pci.h
> index 8edca82..14a0e01 100644
> --- a/lib/ethdev/ethdev_pci.h
> +++ b/lib/ethdev/ethdev_pci.h
> @@ -151,6 +151,19 @@ rte_eth_dev_pci_generic_remove(struct rte_pci_device *pci_dev,
>   	if (!eth_dev)
>   		return 0;
>   
> +	/*
> +	 * The eth_dev->data->name doesn't be cleared by the secondary precess,
Can we reprase above sentence "doesn't be cleared "
> +	 * so above "eth_dev" isn't NULL after rte_eth_dev_close() called.
> +	 * Namely, whether "eth_dev" is NULL cannot be used to determine whether
> +	 * an ethdev port has been released.
> +	 * For both primary precess and secondary precess, eth_dev->state is
s/ precess / process
> +	 * RTE_ETH_DEV_UNUSED, which means the ethdev port has been released.
> +	 */
> +	if (eth_dev->state == RTE_ETH_DEV_UNUSED) {
> +		RTE_ETHDEV_LOG(INFO, "The ethdev port has been released.");
> +		return 0;
> +	}
> +
>   	if (dev_uninit) {
>   		ret = dev_uninit(eth_dev);
>   		if (ret)