From 43189a4b4dbb46f52882de0bf54e8ee2b6de7d4f Mon Sep 17 00:00:00 2001
From: Zhu Lingshan <lszhu@suse.com>
Date: Wed, 2 May 2018 11:13:39 +0800
Subject: [PATCH] scsi: tcmu: add new netlink events helpers
Git-commit: 0e5aee393956f14b82c42486aefc327ba594ca60
Patch-mainline: v4.18-rc1
References: bsc#1118978
Add new netlink events helpers tcmu_netlink_event_init() and
tcmu_netlink_event_send(). These new functions intend to replace
existing netlink events helper function tcmu_netlink_event().
The existing 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.
[mkp: typos]
Signed-off-by: Zhu Lingshan <lszhu@suse.com>
Acked-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
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 7f394f8e629c..261f01cb4a43 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1685,6 +1685,65 @@ 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;
--
2.13.7