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Commit 6635f311 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net/ipv4: Move call_fib_entry_notifiers up for new routes 



Move call to call_fib_entry_notifiers for new IPv4 routes to right
before the call to fib_insert_alias. At this point the only remaining
failure path is memory allocations in fib_insert_node. Handle that
very unlikely failure with a call to call_fib_entry_notifiers to
tell drivers about it.

At this point notifier handlers can decide the fate of the new route
with a clean path to delete the potential new entry if the notifier
returns non-0.

Signed-off-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Reviewed-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9776d325

net/ipv4/fib_trie.c

+16 −2
Original line number Diff line number Diff line
@@ -1065,6 +1065,9 @@ static int fib_insert_node(struct trie *t, struct key_vector *tp, 
	return -ENOMEM;

}



/* fib notifier for ADD is sent before calling fib_insert_alias with

 * the expectation that the only possible failure ENOMEM

 */

static int fib_insert_alias(struct trie *t, struct key_vector *tp,

			    struct key_vector *l, struct fib_alias *new,

			    struct fib_alias *fa, t_key key)
@@ -1263,21 +1266,32 @@ int fib_table_insert(struct net *net, struct fib_table *tb, 
	new_fa->tb_id = tb->tb_id;

	new_fa->fa_default = -1;



	err = call_fib_entry_notifiers(net, event, key, plen, new_fa, extack);

	if (err)

		goto out_free_new_fa;



	/* Insert new entry to the list. */

	err = fib_insert_alias(t, tp, l, new_fa, fa, key);

	if (err)

		goto out_free_new_fa;

		goto out_fib_notif;



	if (!plen)

		tb->tb_num_default++;



	rt_cache_flush(cfg->fc_nlinfo.nl_net);

	call_fib_entry_notifiers(net, event, key, plen, new_fa, extack);

	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,

		  &cfg->fc_nlinfo, nlflags);

succeeded:

	return 0;



out_fib_notif:

	/* notifier was sent that entry would be added to trie, but

	 * the add failed and need to recover. Only failure for

	 * fib_insert_alias is ENOMEM.

	 */

	NL_SET_ERR_MSG(extack, "Failed to insert route into trie");

	call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key,

				 plen, new_fa, NULL);

out_free_new_fa:

	kmem_cache_free(fn_alias_kmem, new_fa);

out: