[dpdk-dev] [PATCH v2 4/4] net/failsafe: fix removed device handling

[Gaëtan Rivet]

Hi Matan,

On Wed, Dec 13, 2017 at 02:29:30PM +0000, Matan Azrad wrote:
> There is time between the physical removal of the device until
> sub-device PMDs get a RMV interrupt. At this time DPDK PMDs and
> applications still don't know about the removal and may call sub-device
> control operation which should return an error.
> 
> In previous code this error is reported to the application contrary to
> fail-safe principle that the app should not be aware of device removal.
> 
> Add an removal check in each relevant control command error flow and
> prevent an error report to application when the sub-device is removed.
> 
> Fixes: a46f8d5 ("net/failsafe: add fail-safe PMD")
> Fixes: b737a1e ("net/failsafe: support flow API")
> Cc: stable at dpdk.org
> 

This patch is not a fix.
It relies on an eth_dev API evolution. Without this evolution,
this patch is meaningless and would break compilation if backported in
stable branch.

Please remove those tags.

> Signed-off-by: Matan Azrad <matan at mellanox.com>
> ---
>  drivers/net/failsafe/failsafe_flow.c    | 18 ++++++++++-------
>  drivers/net/failsafe/failsafe_ops.c     | 34 ++++++++++++++++++++++-----------
>  drivers/net/failsafe/failsafe_private.h | 10 ++++++++++
>  3 files changed, 44 insertions(+), 18 deletions(-)

< ... >

> +/*
> + * Check if sub device was removed.
> + */
> +static inline int
> +fs_is_removed(struct sub_device *sdev)
> +{
> +	if (sdev->remove == 1 || rte_eth_dev_is_removed(PORT_ID(sdev)) != 0)
> +		return 1;
> +	return 0;
> +}

Have you considered adding this check within the subdev iterator itself?
I think it would prevent you from having to add it to each return value
checks.

It is still MT-unsafe anyway.

-- 
Gaëtan Rivet
6WIND