Re: [dpdk-dev] [PATCH V2] ethdev: fix eth device released repeatedly

[Thomas Monjalon <thomas@monjalon.net>]

12/10/2021 13:39, Huisong Li:
> The rte_eth_dev_pci_generic_remove() will be called to detach an Ethernet
> device when App calls rte_dev_remove() to detach a pci device. In addition,
> the rte_eth_dev_close() can also detach an Ethernet device.
> In secondary process, if App first calls rte_eth_dev_close() and then calls
> rte_dev_remove(), because rte_eth_dev_close() doesn't clear "eth_dev->data"

It would be clearer if you start this sentence with:
"In secondary process, rte_eth_dev_close() doesn't clear eth_dev->data."
Then you can explain that if calling rte_dev_remove() after rte_eth_dev_close(),
etc...

> , the address of the released Ethernet device can still be found by device
> name. As a result, the Ethernet device will be released repeatedly in this
> case. The state of the Ethernet device is equal to RTE_ETH_DEV_UNUSED after
> calling rte_eth_dev_close(). Use this state to avoid this problem.
> 
> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> ---
> +	/*
> +	 * In secondary process, if applications first call rte_eth_dev_close()
> +	 * and then call this interface, because rte_eth_dev_close() doesn't
> +	 * clear eth_dev->data, the address of the released Ethernet device can
> +	 * still be found by device name. As a result, the Ethernet device will
> +	 * be released repeatedly in this case.
> +	 * The state of the Ethernet device is equal to RTE_ETH_DEV_UNUSED after
> +	 * calling rte_eth_dev_close(). Use this state to avoid this problem.

This is a comment for the commit log.
Inside the code, we should be more to the point.
I suggest this comment:
/* A released port can be found by its name in shared memory. */

> +	 */
> +	if (rte_eal_process_type() != RTE_PROC_PRIMARY &&

Better to directly compare with RTE_PROC_SECONDARY

> +	    eth_dev->state == RTE_ETH_DEV_UNUSED) {
> +		RTE_ETHDEV_LOG(INFO, "The ethdev port has been released.");

Not sure we need any log here.

> +		return 0;
> +	}