nft_hash: Remove rhashtable_remove_pprev()
authorThomas Graf <tgraf@suug.ch>
Fri, 2 Jan 2015 22:00:18 +0000 (23:00 +0100)
committerDavid S. Miller <davem@davemloft.net>
Sat, 3 Jan 2015 19:32:57 +0000 (14:32 -0500)
commit897362e446436d245972e72c6bc5b33bd7a5c659
treeefddc040f4d1042b486100cb20c3c3036b292420
parentb8e1943e9f754219bcfb40bac4a605b5348acb25
nft_hash: Remove rhashtable_remove_pprev()

The removal function of nft_hash currently stores a reference to the
previous element during lookup which is used to optimize removal later
on. This was possible because a lock is held throughout calling
rhashtable_lookup() and rhashtable_remove().

With the introdution of deferred table resizing in parallel to lookups
and insertions, the nftables lock will no longer synchronize all
table mutations and the stored pprev may become invalid.

Removing this optimization makes removal slightly more expensive on
average but allows taking the resize cost out of the insert and
remove path.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Cc: netfilter-devel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/rhashtable.h
lib/rhashtable.c
net/netfilter/nft_hash.c