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authorDavid Fries <David@Fries.net>2014-04-08 22:37:08 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-27 13:56:21 -0700
commit34470e0bfae223e3f22bd2bd6e0e1dac366c9290 (patch)
treef1c90448f6a4c2b23923498f954a72136ca1392a
parentfd1a73c60ee0bfd3fefc96ad270effd69b350aba (diff)
downloadlinux-34470e0bfae223e3f22bd2bd6e0e1dac366c9290.tar.bz2
connector: allow multiple messages to be sent in one packet
This increases the amount of bundling to reduce the number of packets sent. For the one wire use there can be multiple struct w1_netlink_cmd in a struct w1_netlink_msg and multiple of those in struct cn_msg, and with this change multiple of those in a struct nlmsghdr, and at each level the len identifies there being multiple of the next. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--Documentation/connector/connector.txt13
-rw-r--r--drivers/connector/connector.c17
-rw-r--r--include/linux/connector.h1
3 files changed, 26 insertions, 5 deletions
diff --git a/Documentation/connector/connector.txt b/Documentation/connector/connector.txt
index e5c5f5e6ab70..e56abdb21975 100644
--- a/Documentation/connector/connector.txt
+++ b/Documentation/connector/connector.txt
@@ -24,7 +24,8 @@ netlink based networking for inter-process communication in a significantly
easier way:
int cn_add_callback(struct cb_id *id, char *name, void (*callback) (struct cn_msg *, struct netlink_skb_parms *));
-void cn_netlink_send(struct cn_msg *msg, u32 __group, int gfp_mask);
+void cn_netlink_send_multi(struct cn_msg *msg, u16 len, u32 portid, u32 __group, int gfp_mask);
+void cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group, int gfp_mask);
struct cb_id
{
@@ -71,15 +72,21 @@ void cn_del_callback(struct cb_id *id);
struct cb_id *id - unique connector's user identifier.
-int cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask);
+int cn_netlink_send_multi(struct cn_msg *msg, u16 len, u32 portid, u32 __groups, int gfp_mask);
+int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __groups, int gfp_mask);
Sends message to the specified groups. It can be safely called from
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).
+ u16 len - for *_multi multiple cn_msg messages can be sent
+ u32 port - destination port.
+ If non-zero the message will be sent to the
+ given port, which should be set to the
+ original sender.
u32 __group - destination group.
- If __group is zero, then appropriate group will
+ If port and __group is zero, then appropriate group will
be searched through all registered connector users,
and message will be delivered to the group which was
created for user with the same ID as in msg.
diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index b14f1d36f897..f612d68629dc 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -43,6 +43,8 @@ static struct cn_dev cdev;
static int cn_already_initialized;
/*
+ * Sends mult (multiple) cn_msg at a time.
+ *
* msg->seq and msg->ack are used to determine message genealogy.
* When someone sends message it puts there locally unique sequence
* and random acknowledge numbers. Sequence number may be copied into
@@ -62,10 +64,13 @@ static int cn_already_initialized;
* the acknowledgement number in the original message + 1, then it is
* a new message.
*
+ * If msg->len != len, then additional cn_msg messages are expected following
+ * the first msg.
+ *
* The message is sent to, the portid if given, the group if given, both if
* both, or if both are zero then the group is looked up and sent there.
*/
-int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
+int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group,
gfp_t gfp_mask)
{
struct cn_callback_entry *__cbq;
@@ -98,7 +103,7 @@ int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
if (!portid && !netlink_has_listeners(dev->nls, group))
return -ESRCH;
- size = sizeof(*msg) + msg->len;
+ size = sizeof(*msg) + len;
skb = nlmsg_new(size, gfp_mask);
if (!skb)
@@ -121,6 +126,14 @@ int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
gfp_mask);
return netlink_unicast(dev->nls, skb, portid, !(gfp_mask&__GFP_WAIT));
}
+EXPORT_SYMBOL_GPL(cn_netlink_send_mult);
+
+/* same as cn_netlink_send_mult except msg->len is used for len */
+int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
+ gfp_t gfp_mask)
+{
+ return cn_netlink_send_mult(msg, msg->len, portid, __group, gfp_mask);
+}
EXPORT_SYMBOL_GPL(cn_netlink_send);
/*
diff --git a/include/linux/connector.h b/include/linux/connector.h
index be9c4747d511..f8fe8637d771 100644
--- a/include/linux/connector.h
+++ b/include/linux/connector.h
@@ -71,6 +71,7 @@ struct cn_dev {
int cn_add_callback(struct cb_id *id, const char *name,
void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
void cn_del_callback(struct cb_id *);
+int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 group, gfp_t gfp_mask);
int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,