Commit 7d88d8b5 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

ipv6: Refactor fib6_drop_pcpu_from 



Move the existing pcpu walk in fib6_drop_pcpu_from to a new
helper, __fib6_drop_pcpu_from, that can be invoked per fib6_nh with a
reference to the from entries that need to be evicted. If the passed
in 'from' is non-NULL then only entries associated with that fib6_info
are removed (e.g., case where fib entry is deleted); if the 'from' is
NULL are entries are flushed (e.g., fib6_nh is deleted).

For fib6_info entries with builtin fib6_nh (ie., current code) there
is no change in behavior.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f40b6ae2

net/ipv6/ip6_fib.c

+25 −10
Original line number Diff line number Diff line
@@ -874,21 +874,15 @@ insert_above: 
	return ln;

}



static void fib6_drop_pcpu_from(struct fib6_info *f6i,

static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,

				  const struct fib6_info *match,

				  const struct fib6_table *table)

{

	struct fib6_nh *fib6_nh = &f6i->fib6_nh;

	int cpu;



	if (!fib6_nh->rt6i_pcpu)

		return;



	/* Make sure rt6_make_pcpu_route() wont add other percpu routes

	 * while we are cleaning them here.

	 */

	f6i->fib6_destroying = 1;

	mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */



	/* release the reference to this fib entry from

	 * all of its cached pcpu routes

	 */
@@ -898,7 +892,13 @@ static void fib6_drop_pcpu_from(struct fib6_info *f6i, 


		ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);

		pcpu_rt = *ppcpu_rt;

		if (pcpu_rt) {



		/* only dropping the 'from' reference if the cached route

		 * is using 'match'. The cached pcpu_rt->from only changes

		 * from a fib6_info to NULL (ip6_dst_destroy); it can never

		 * change from one fib6_info reference to another

		 */

		if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) {

			struct fib6_info *from;



			from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
@@ -907,6 +907,21 @@ static void fib6_drop_pcpu_from(struct fib6_info *f6i, 
	}

}



static void fib6_drop_pcpu_from(struct fib6_info *f6i,

				const struct fib6_table *table)

{

	struct fib6_nh *fib6_nh;



	/* Make sure rt6_make_pcpu_route() wont add other percpu routes

	 * while we are cleaning them here.

	 */

	f6i->fib6_destroying = 1;

	mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */



	fib6_nh = &f6i->fib6_nh;

	__fib6_drop_pcpu_from(fib6_nh, f6i, table);

}



static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,

			  struct net *net)

{

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