[libvirt] [PATCH v2] nodedev: Increase the netlink socket buffer size to the one used by udev

[Daniel P. Berrange]

On Fri, May 19, 2017 at 03:16:26PM +0200, Erik Skultety wrote:
> From: "ning.bo" <ning.bo9 at zte.com.cn>
> 
> When a number of SRIOV VFs (up to 128 on Intel XL710) is created:
> for i in `seq 0 1`; do
>   echo 63 > /sys/class/net/<interface>/device/sriov_numvfs
> done
> 
> libvirtd will then report "udev_monitor_receive_device returned NULL"
> error because the netlink socket buffer is not big enough (using GDB on
> libudev confirmed this with ENOBUFFS) and thus some udev events were
> dropped. This results in some devices being missing in the nodedev-list
> output. This patch overrides the system's rmem_max limit but for that,
> we need to make sure we've got root privileges.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1450960
> 
> Signed-off-by: ning.bo <ning.bo9 at zte.com.cn>
> Signed-off-by: Erik Skultety <eskultet at redhat.com>
> ---
> Additionally, we might want to check for the errno, providing a specific
> message if such issue occurs again in a further non-specified point in time and
> return the generic, yet cryptic one for all other cases.
> 
>  src/node_device/node_device_udev.c | 7 +++++++
>  1 file changed, 7 insertions(+)

This has broken the build on older systems  as udev doesn't have this
method.


Regards,
Daniel
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