Add new netlink events helpers tcmu_netlink_event_init() and
tcmu_netlink_event_send(). These new functions intend to replace
exsiting netlink events helper function tcmu_netlink_event().
The exsiting function tcmu_netlink_event() works well for events
like TCMU_ADDED_DEVICE and TCMU_REMOVED_DEVICE which only has one
netlink attribute. But if there is a command requires more than
one attributes to send out, we have to use a struct to adapt the
paremeter reconfig_data, it is hard to use one struct or a union
in one struct to adapt every command with different attributes,
it may get long and ugly.
With the new two functions, we can call tcmu_netlink_event_init()
to initialize a netlink event, then add all attributes we need by
using nla_put_xxx(), at last use tcmu_netlink_event_send() to
send it out. So that we don't need to use a long struct or union
if we want to send mulitple attributes for different commands.
Signed-off-by: Zhu Lingshan <lszhu@xxxxxxxx>
---
Changes in V2:
- Add new blank lines for better code style, easier to
scan the chunks
drivers/target/target_core_user.c | 59 +++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 4ad89ea71a70..d8f6a53f6bca 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1653,6 +1653,65 @@ static int tcmu_netlink_event(struct tcmu_dev *udev, enum tcmu_genl_cmd cmd,
return ret;
}
+static int tcmu_netlink_event_init(struct tcmu_dev *udev,
+ enum tcmu_genl_cmd cmd,
+ struct sk_buff **buf, void **hdr)
+{
+ struct sk_buff *skb;
+ void *msg_header;
+ int ret = -ENOMEM;
+
+ skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!skb)
+ return ret;
+
+ msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
+ if (!msg_header)
+ goto free_skb;
+
+ ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
+ if (ret < 0)
+ goto free_skb;
+
+ ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
+ if (ret < 0)
+ goto free_skb;
+
+ ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
+ if (ret < 0)
+ goto free_skb;
+
+ *buf = skb;
+ *hdr = msg_header;
+ return ret;
+
+free_skb:
+ nlmsg_free(skb);
+ return ret;
+}
+
+static int tcmu_netlink_event_send(struct tcmu_dev *udev,
+ enum tcmu_genl_cmd cmd,
+ struct sk_buff **buf, void **hdr)
+{
+ int ret = 0;
+ struct sk_buff *skb = *buf;
+ void *msg_header = *hdr;
+
+ genlmsg_end(skb, msg_header);
+
+ tcmu_init_genl_cmd_reply(udev, cmd);
+
+ ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
+ TCMU_MCGRP_CONFIG, GFP_KERNEL);
+ /* We don't care if no one is listening */
+ if (ret == -ESRCH)
+ ret = 0;
+ if (!ret)
+ ret = tcmu_wait_genl_cmd_reply(udev);
+ return ret;
+}
+
static int tcmu_update_uio_info(struct tcmu_dev *udev)
{
struct tcmu_hba *hba = udev->hba->hba_ptr;
--
2.14.3
