If CONFIG_IPV6=m, the IPV6 functions won't be found by the linker:

ld: net/core/fib_rules.o: in function `fib_rules_lookup':
fib_rules.c:(.text+0x606): undefined reference to `fib6_rule_match'
ld: fib_rules.c:(.text+0x611): undefined reference to `fib6_rule_match'
ld: fib_rules.c:(.text+0x68c): undefined reference to `fib6_rule_action'
ld: fib_rules.c:(.text+0x693): undefined reference to `fib6_rule_action'
ld: fib_rules.c:(.text+0x6aa): undefined reference to `fib6_rule_suppress'
ld: fib_rules.c:(.text+0x6bc): undefined reference to `fib6_rule_suppress'
make: *** [Makefile:1166: vmlinux] Error 1

Reported-by: Sven Joachim <svenjoac@gmx.de>
Fixes: b9aaec8f0be5 ("fib: use indirect call wrappers in the most common fib_rules_ops")
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/fib_rules.c:26:7: warning: "CONFIG_IP_MULTIPLE_TABLES" is not defined, evaluates to 0 [-Wundef]
 #elif CONFIG_IP_MULTIPLE_TABLES
       ^~~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 8b66a6fd34f5 ("fib: fix another fib_rules_ops indirect call wrapper problem")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-By: Brian Vazquez <brianvv@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It turns out that on commit 41d707b7332f ("fib: fix fib_rules_ops
indirect calls wrappers") I forgot to include the case when
CONFIG_IP_MULTIPLE_TABLES is not set.

Fixes: 41d707b7332f ("fib: fix fib_rules_ops indirect calls wrappers")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes:
commit b9aaec8f0be5 ("fib: use indirect call wrappers in the most common
fib_rules_ops") which didn't consider the case when
CONFIG_IPV6_MULTIPLE_TABLES is not set.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: b9aaec8f0be5 ("fib: use indirect call wrappers in the most common fib_rules_ops")
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This avoids another inderect call per RX packet which save us around
20-40 ns.

Changelog:

v1 -> v2:
- Move declaraions to fib_rules.h to remove warnings

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In 709772e6e06564ed94ba740de70185ac3d792773, RT_TABLE_COMPAT was added to
allow legacy software to deal with routing table numbers >= 256, but the
same change to FIB rule queries was overlooked.

Signed-off-by: Jethro Beekman <jethro@fortanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since errors are propagated all the way up to the caller, propagate
possible extack of the caller all the way down to the notifier block
callback.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Unlike events for registered notifier, during the registration, the
errors that happened for the block being registered are not propagated
up to the caller. Make sure the error is propagated for FIB rules and
entries.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently all users of FIB notifier only cares about events in init_net.
Later in this patchset, users get interested in other namespaces too.
However, for every registered block user is interested only about one
namespace. Make the FIB notifier registration per-netns and avoid
unnecessary calls of notifier block for other namespaces.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull yet more SPDX updates from Greg KH:
 "Another round of SPDX header file fixes for 5.2-rc4

  These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
  added, based on the text in the files. We are slowly chipping away at
  the 700+ different ways people tried to write the license text. All of
  these were reviewed on the spdx mailing list by a number of different
  people.

  We now have over 60% of the kernel files covered with SPDX tags:
	$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
	Files checked:            64533
	Files with SPDX:          40392
	Files with errors:            0

  I think the majority of the "easy" fixups are now done, it's now the
  start of the longer-tail of crazy variants to wade through"

* tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429
  ...