[PATCHv2 1/3] nvme: send uevent on connection up

Martin Belanger
2022-02-03T21:18:50Z

From: Martin Belanger <martin.belanger@dell.com>

When connectivity with a controller is lost, the driver will keep
trying to reconnect once every 10 sec. When connection is restored,
user-space apps need to be informed so that they can take proper
action. For example, TP8010 introduces the DIM PDU, which is used to
register with a discovery controller (DC). The DIM PDU is sent from
user-space. The DIM PDU must be sent every time a connection is
established with a DC. Therefore, the kernel must tell user-space apps
when connection is restored so that registration can happen.

The uevent sent is a "change" uevent with environmental data
set to: "NVME_EVENT=connected".

Signed-off-by: Martin Belanger <martin.belanger@dell.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
---
drivers/nvme/host/core.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index dd18861f77c0..b5e452aa3c0e 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4229,6 +4229,13 @@ static int nvme_class_uevent(struct device *dev, struct kobj_uevent_env *env)
return ret;
}

+static void nvme_change_uevent(struct nvme_ctrl *ctrl, char *envdata)
+{
+ char *envp[2] = { envdata, NULL };
+
+ kobject_uevent_env(&ctrl->device->kobj, KOBJ_CHANGE, envp);
+}
+
static void nvme_aen_uevent(struct nvme_ctrl *ctrl)
{
char *envp[2] = { NULL, NULL };
@@ -4396,6 +4403,8 @@ void nvme_start_ctrl(struct nvme_ctrl *ctrl)
nvme_queue_scan(ctrl);
nvme_start_queues(ctrl);
}
+
+ nvme_change_uevent(ctrl, "NVME_EVENT=connected");
}
EXPORT_SYMBOL_GPL(nvme_start_ctrl);

--
2.34.1