Commit f46ef9e8 authored by Sagi Grimberg's avatar Sagi Grimberg Committed by Christoph Hellwig
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nvme: send a rediscover uevent when a persistent discovery controller reconnects 



When a discovery controller is disconnected, no AENs will arrive to
notify the host about discovery log change events.

In order to solve this, send a uevent notification when a
persistent discovery controller reconnects. We add a new ctrl
flag NVME_CTRL_STARTED_ONCE that will be set on the first
start, and consecutive calls will find it set, and send the
event to userspace if the controller is a discovery controller.

Upon the event reception, userspace will re-read the discovery
log page and will act upon changes as it sees fit.

Signed-off-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarDaniel Wagner <dwagner@suse.de>
Reviewed-by: default avatarJames Smart <jsmart2021@gmail.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent bf093d97

drivers/nvme/host/core.c

+10 −0
Original line number Diff line number Diff line
@@ -4815,6 +4815,16 @@ void nvme_start_ctrl(struct nvme_ctrl *ctrl) 


	nvme_enable_aen(ctrl);



	/*

	 * persistent discovery controllers need to send indication to userspace

	 * to re-read the discovery log page to learn about possible changes

	 * that were missed. We identify persistent discovery controllers by

	 * checking that they started once before, hence are reconnecting back.

	 */

	if (test_and_set_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags) &&

	    nvme_discovery_ctrl(ctrl))

		nvme_change_uevent(ctrl, "NVME_EVENT=rediscover");



	if (ctrl->queue_count > 1) {

		nvme_queue_scan(ctrl);

		nvme_start_queues(ctrl);

drivers/nvme/host/nvme.h

+1 −0
Original line number Diff line number Diff line
@@ -236,6 +236,7 @@ struct nvme_fault_inject { 
enum nvme_ctrl_flags {

	NVME_CTRL_FAILFAST_EXPIRED	= 0,

	NVME_CTRL_ADMIN_Q_STOPPED	= 1,

	NVME_CTRL_STARTED_ONCE		= 2,

};



struct nvme_ctrl {