From b191ba0d599928372be5a89f75486eb58efab48a Mon Sep 17 00:00:00 2001 From: Evgeniy Polyakov Date: Mon, 20 Mar 2006 22:21:40 -0800 Subject: [PATCH] [CONNECTOR]: Use netlink_has_listeners() to avoind unnecessary allocations. 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 Signed-off-by: David S. Miller --- Documentation/connector/connector.txt | 5 +++-- drivers/connector/connector.c | 7 ++++--- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/Documentation/connector/connector.txt b/Documentation/connector/connector.txt index 57a314b14cf8..ad6e0ba7b38c 100644 --- a/Documentation/connector/connector.txt +++ b/Documentation/connector/connector.txt @@ -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. diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c index 505677fb3157..d7125f4d9113 100644 --- a/drivers/connector/connector.c +++ b/drivers/connector/connector.c @@ -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); -- 2.39.2