DST_NOCOUNT in dst_entry::flags tracks whether the entry counts
toward route cache size (net->ipv6.sysctl.ip6_rt_max_size).
If the flag is NOT set, dst_ops::pcpuc_entries counter is incremented
in dist_init() and decremented in dst_destroy().
This flag is tied to allocation/deallocation of dst_entry and
should not be copied from another dst/route. Otherwise it can happen
that dst_ops::pcpuc_entries counter grows until no new routes can
be allocated because the counter reached ip6_rt_max_size due to
DST_NOCOUNT not set and thus no counter decrements on gc-ed routes.
Fixes: 3b6761d18b ("net/ipv6: Move dst flags to booleans in fib entries")
Cc: David Ahern <[email protected]>
Acked-by: Wei Wang <[email protected]>
Signed-off-by: Peter Oskolkov <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Peter Oskolkov
30bfd93062