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rtnetlink: call rtnl_calcit directly

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There is only a single place in the kernel that regisers the "calcit"
callback (to determine min allocation for dumps).

This is in rtnetlink.c for PF_UNSPEC RTM_GETLINK.
The function that checks for calcit presence at run time will first check
the requested family (which will always fail for !PF_UNSPEC as no callsite
registers this), then falls back to checking PF_UNSPEC.

Therefore we can just check if type is RTM_GETLINK and then do a direct
call.  Because of fallback to PF_UNSPEC all RTM_GETLINK types used this
regardless of family.

This has the advantage that we don't need to allocate space for
the function pointer for all the other families.

A followup patch will drop the calcit function pointer from the
rtnl_link callback structure.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Westphal 2017-08-09 20:41:47 +02:00 committed by David S. Miller
parent 078295fb9a
commit e1fa6d216d
1 changed files with 4 additions and 25 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

29
net/core/rtnetlink.c
View file

@ -62,7 +62,6 @@
struct rtnl_link {
rtnl_doit_func doit;
rtnl_dumpit_func dumpit;
rtnl_calcit_func calcit;
};
static DEFINE_MUTEX(rtnl_mutex);
@ -173,21 +172,6 @@ static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
return tab[msgindex].dumpit;
}
static rtnl_calcit_func rtnl_get_calcit(int protocol, int msgindex)
{
struct rtnl_link *tab;
if (protocol <= RTNL_FAMILY_MAX)
tab = rtnl_msg_handlers[protocol];
else
tab = NULL;
if (tab == NULL || tab[msgindex].calcit == NULL)
tab = rtnl_msg_handlers[PF_UNSPEC];
return tab[msgindex].calcit;
}
/**
* __rtnl_register - Register a rtnetlink message type
* @protocol: Protocol family or PF_UNSPEC
@ -231,9 +215,6 @@ int __rtnl_register(int protocol, int msgtype,
if (dumpit)
tab[msgindex].dumpit = dumpit;
if (calcit)
tab[msgindex].calcit = calcit;
return 0;
}
EXPORT_SYMBOL_GPL(__rtnl_register);
@ -277,7 +258,6 @@ int rtnl_unregister(int protocol, int msgtype)
rtnl_msg_handlers[protocol][msgindex].doit = NULL;
rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
rtnl_msg_handlers[protocol][msgindex].calcit = NULL;
return 0;
}
@ -4187,15 +4167,14 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
struct sock *rtnl;
rtnl_dumpit_func dumpit;
rtnl_calcit_func calcit;
u16 min_dump_alloc = 0;
dumpit = rtnl_get_dumpit(family, type);
if (dumpit == NULL)
return -EOPNOTSUPP;
calcit = rtnl_get_calcit(family, type);
if (calcit)
min_dump_alloc = calcit(skb, nlh);
if (type == RTM_GETLINK)
min_dump_alloc = rtnl_calcit(skb, nlh);
__rtnl_unlock();
rtnl = net->rtnl;
@ -4300,7 +4279,7 @@ void __init rtnetlink_init(void)
register_netdevice_notifier(&rtnetlink_dev_notifier);
rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
rtnl_dump_ifinfo, rtnl_calcit);
rtnl_dump_ifinfo, NULL);
rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, NULL);
rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, NULL);
rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, NULL);