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[CONNECTOR]: Use netlink_has_listeners() to avoind unnecessary allocations.

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Return -ESRCH from cn_netlink_send() when there are not listeners,
just as it could be done by netlink_broadcast().  Propagate
netlink_broadcast() error back to the caller.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Evgeniy Polyakov 2006-03-20 22:21:40 -08:00 committed by David S. Miller
parent 0ac81ae34e
commit b191ba0d59
2 changed files with 7 additions and 5 deletions
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5
Documentation/connector/connector.txt
View file

@ -69,10 +69,11 @@ Unregisters new callback with connector core.
struct cb_id *id - unique connector's user identifier.
void cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask);
int cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask);
Sends message to the specified groups. It can be safely called from
any context, but may silently fail under strong memory pressure.
softirq context, but may silently fail under strong memory pressure.
If there are no listeners for given group -ESRCH can be returned.
struct cn_msg * - message header(with attached data).
u32 __group - destination group.

7
drivers/connector/connector.c
View file

@ -97,6 +97,9 @@ int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
group = __group;
}
if (!netlink_has_listeners(dev->nls, group))
return -ESRCH;
size = NLMSG_SPACE(sizeof(*msg) + msg->len);
skb = alloc_skb(size, gfp_mask);
@ -111,9 +114,7 @@ int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
NETLINK_CB(skb).dst_group = group;
netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
return 0;
return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
nlmsg_failure:
kfree_skb(skb);