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Wei Wang authored
In IPv4 routing code, fib_nh and fib_nh_exception can hold pointers to struct rtable but they never increment dst->__refcnt. This leads to the need of the dst garbage collector because when user is done with this dst and calls dst_release(), it can only decrement dst->__refcnt and can not free the dst even it sees dst->__refcnt drops from 1 to 0 (unless DST_NOCACHE flag is set) because the routing code might still hold reference to it. And when the routing code tries to delete a route, it has to put the dst to the gc_list if dst->__refcnt is not yet 0 and have a gc thread running periodically to check on dst->__refcnt and finally to free dst when refcnt becomes 0. This patch increments dst->__refcnt when fib_nh/fib_nh_exception holds reference to this dst and properly release the dst when fib_nh/fib_nh_exception has been updated with a new dst. This patch is a preparation in order to fully get rid of dst gc later. Signed-off-by:
Wei Wang <weiwan@google.com> Acked-by:
Martin KaFai Lau <kafai@fb.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
0830106c