[RESEND V2 5/6] tcmu: refactor nl dev_size attr with new helpers

[Zhu Lingshan]

use new netlink events helpers tcmu_netlink_init() and
tcmu_netlink_send() to refactor netlink event attribute
TCMU_ATTR_DEV_SIZE(belongs to TCMU_CMD_RECONFIG_DEVICE)
which is also dev_size in configFS.

Signed-off-by: Zhu Lingshan <ls...@suse.com>
---
Changes in V2:
  - return tcmu_netlink_event_send() directly, instead of a ret value.
  
 drivers/target/target_core_user.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/target/target_core_user.c 
b/drivers/target/target_core_user.c
index 21ce7dd8420d..c5bc2e1a9c49 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2299,6 +2299,26 @@ static ssize_t tcmu_dev_size_show(struct config_item 
*item, char *page)
        return snprintf(page, PAGE_SIZE, "%zu\n", udev->dev_size);
 }
 
+static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
+{
+       struct sk_buff *skb = NULL;
+       void *msg_header = NULL;
+       int ret = 0;
+
+       ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
+                                     &skb, &msg_header);
+       if (ret < 0)
+               return ret;
+       ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
+                               size, TCMU_ATTR_PAD);
+       if (ret < 0) {
+               nlmsg_free(skb);
+               return ret;
+       }
+       return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
+                                      &skb, &msg_header);
+}
+
 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
                                   size_t count)
 {
@@ -2314,8 +2334,7 @@ static ssize_t tcmu_dev_size_store(struct config_item 
*item, const char *page,
 
        /* Check if device has been configured before */
        if (tcmu_dev_configured(udev)) {
-               ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
-                                        TCMU_ATTR_DEV_SIZE, &val);
+               ret = tcmu_send_dev_size_event(udev, val);
                if (ret) {
                        pr_err("Unable to reconfigure device\n");
                        return ret;
-- 
2.14.3