linux/include
Ido Schimmel c3852ef7f2 ipv4: fib: Replay events when registering FIB notifier
Commit b90eb75494 ("fib: introduce FIB notification infrastructure")
introduced a new notification chain to notify listeners (f.e., switchdev
drivers) about addition and deletion of routes.

However, upon registration to the chain the FIB tables can already be
populated, which means potential listeners will have an incomplete view
of the tables.

Solve that by dumping the FIB tables and replaying the events to the
passed notification block. The dump itself is done using RCU in order
not to starve consumers that need RTNL to make progress.

The integrity of the dump is ensured by reading the FIB change sequence
counter before and after the dump under RTNL. This allows us to avoid
the problematic situation in which the dumping process sends a ENTRY_ADD
notification following ENTRY_DEL generated by another process holding
RTNL.

Callers of the registration function may pass a callback that is
executed in case the dump was inconsistent with current FIB tables.

The number of retries until a consistent dump is achieved is set to a
fixed number to prevent callers from looping for long periods of time.
In case current limit proves to be problematic in the future, it can be
easily converted to be configurable using a sysctl.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 19:29:35 -05:00
..
acpi Merge branches 'acpica-fixes', 'acpi-cppc-fixes' and 'acpi-tools-fixes' 2016-11-18 21:34:42 +01:00
asm-generic default exported asm symbols to zero 2016-12-02 08:51:22 -08:00
clocksource
crypto
drm drm: Don't force all planes to be added to the state due to zpos 2016-10-26 18:48:05 +02:00
dt-bindings dt-bindings: net: add EEE capability constants 2016-11-29 19:38:31 -05:00
keys
kvm
linux Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
math-emu
media
memory
misc
net ipv4: fib: Replay events when registering FIB notifier 2016-12-03 19:29:35 -05:00
pcmcia
ras
rdma
rxrpc
scsi
soc
sound
target
trace net/phy: add trace events for mdio accesses 2016-11-24 11:55:43 -05:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
video
xen
Kbuild