Merge branch 'net-sched-extack'

Merge branch 'net-sched-extack'

Alexander Aring says:

====================
net: sched: sch: introduce extack support

this patch series basically add support for extack in common qdisc handling.
Additional it adds extack pointer to common qdisc callback handling this
offers per qdisc implementation to setting the extack message for each
failure over netlink.

The extack message will be set deeper in qdisc functions but going not
deeper as net core api. For qdisc module callback handling, the extack
will not be set. This will be part of per qdisc extack handling.

I also want to prepare patches to handle extack per qdisc module...
so there will come a lot of more patches, just cut them down to make
it reviewable.

There are some above 80-chars width warnings, which I ignore because
it looks more ugly otherwise.

This patch-series based on patches by David Ahern which gave me some
hints how to deal with extack support.

Cc: David Ahern <dsahern@gmail.com>
changes since v4:
 - rebase on current net-next/master
 - fix several typos (also David Ahren to Ahern, I am sorry)
 - Add acked by Jamal

changes since v3:
 - remove patch 2/2 lib: nlattr: set extack msg if validate_nla fails since
   David Ahern has a better solution
 - Remove check on net admin permission since -EPERM indicates it already
 - Change rtab to "rate table" - this is what it's stands for
 - Fix cbs *not* support messages
 - Fix tcf block error message for allocation, allocation will be still there
   because there are multiple places which returns -ENOMEM
 - Finnally also took care about sch_atm, sorry somehow I forgot this one and
   I hope I didn't forgot any sch implementation to add new callback parameters

changes since v2:
 - add fix coding style patch to catch all checkpatch warnings
 - add patch for setting netlink extack msg if validate_nla fails
 - changes in handle generic qdisc errors
   - remove NL_SET_ERR_MSG from memory allocation errors
   - remove NL_SET_ERR_MSG from device not found
   - change STAB to table size
 - add various new patches to add extack support for common
   TC functions like qdisc_get_rtab, tcf_block_get, qdisc_alloc
   and qdisc_create_dflt - users which are interessted in the
   detailed error messages can assign extack, otherwise NULL.
 - Add sch_cbq as example for qdisc_ops callback: init,
   qdisc_class_ops callbacks: change and graft
 - Add sch_cbs as example for qdisc_ops callback: change
 - Add sch_drr as example for qdisc_class ops callbacks: tcf_block
====================

Signed-off-by: David S. Miller <davem@davemloft.net>