[ovs-dev] [PATCH v2 2/6] netdev-linux: Cache error code from mtu ioctl.

[Ben Pfaff]

On Thu, Mar 08, 2012 at 07:26:23AM -0800, Pravin B Shelar wrote:
> Fixed according to comments from Ben.
> v1-v2:
>      - Fixed check for MTU in notifier so that mtu is not set to zero.
>      - Changed check for VALID_MTU.
> 
> --8<--------------------------cut here-------------------------->8--
> netdev linux devices uses mtu ioctl to get and set MTU for a device.
> By caching error code from ioctl we can reduce number of ioctl calls
> for device which is unregistered from system.
> netdev notification is used to update mtu which saves get-mtu-ioctl.
> 
> Signed-off-by: Pravin B Shelar <pshelar at nicira.com>

In netdev_linux_set_mtu(), I don't think that it is wise to update the
cache in case of an error: if we try to, for example, set an invalid
MTU, then the next call to netdev_linux_get_mtu() for the device would
report that error instead of the device's actual MTU.

Otherwise this looks fine to me.  Thank you.