Re: [dpdk-dev] [dpdk-stable] [PATCH v3 2/5] net/tap: fix mbuf and mem leak during queue release

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 4/7/2020 5:22 AM, wangyunjian wrote:
> From: Yunjian Wang <wangyunjian@huawei.com>
> 
> For the tap PMD, we should release mbufs and iovecs from the Rx queue
> when close or remove device.
> 
> Fixes: 0781f5762cfe ("net/tap: support segmented mbufs")
> CC: stable@dpdk.org
> 
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
>  drivers/net/tap/rte_eth_tap.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> index 4c4b6b0b2..a9ba0ca68 100644
> --- a/drivers/net/tap/rte_eth_tap.c
> +++ b/drivers/net/tap/rte_eth_tap.c
> @@ -1022,6 +1022,7 @@ tap_dev_close(struct rte_eth_dev *dev)
>  	int i;
>  	struct pmd_internals *internals = dev->data->dev_private;
>  	struct pmd_process_private *process_private = dev->process_private;
> +	struct rx_queue *rxq;
>  
>  	tap_link_set_down(dev);
>  	tap_flow_flush(dev, NULL);
> @@ -1029,8 +1030,13 @@ tap_dev_close(struct rte_eth_dev *dev)
>  
>  	for (i = 0; i < RTE_PMD_TAP_MAX_QUEUES; i++) {
>  		if (process_private->rxq_fds[i] != -1) {
> +			rxq = &internals->rxq[i];
>  			close(process_private->rxq_fds[i]);
>  			process_private->rxq_fds[i] = -1;
> +			rte_pktmbuf_free(rxq->pool);
> +			rte_free(rxq->iovecs);
> +			rxq->pool = NULL;
> +			rxq->iovecs = NULL;
>  		}
>  		if (process_private->txq_fds[i] != -1) {
>  			close(process_private->txq_fds[i]);
> @@ -2399,6 +2405,7 @@ rte_pmd_tap_remove(struct rte_vdev_device *dev)
>  	struct rte_eth_dev *eth_dev = NULL;
>  	struct pmd_internals *internals;
>  	struct pmd_process_private *process_private;
> +	struct rx_queue *rxq;
>  	int i;
>  
>  	/* find the ethdev entry */
> @@ -2425,8 +2432,13 @@ rte_pmd_tap_remove(struct rte_vdev_device *dev)
>  	}
>  	for (i = 0; i < RTE_PMD_TAP_MAX_QUEUES; i++) {
>  		if (process_private->rxq_fds[i] != -1) {
> +			rxq = &internals->rxq[i];
>  			close(process_private->rxq_fds[i]);
>  			process_private->rxq_fds[i] = -1;
> +			rte_pktmbuf_free(rxq->pool);
> +			rte_free(rxq->iovecs);
> +			rxq->pool = NULL;
> +			rxq->iovecs = NULL;
>  		}
>  		if (process_private->txq_fds[i] != -1) {
>  			close(process_private->txq_fds[i]);
> 

Thanks for the fix, but instead of duplicating this for 'close()' & 'remove()',
can 'remove()' call the 'close()'?
They should be doing almost same thing but I can see there is difference between
two, which may mean something is missed, unifying them fixes those missed parts too.
Just a reminder that there can be tree valid path and should work fine:
1- user 'close()' the PMD
2- user directly 'remove()' the PMD
3- user first 'close()', later 'remove()' the PMD

Thanks,
ferruh