Subject: [PATCH AUTOSEL 4.19 4/7] Revert "xen-netback: remove 'hotplug-status' once it has served its purpose"

From: Sasha Levin <[email-masked]>
Date: Tue, 1 Mar 2022 15:20:42 -0500

From: Marek Marczykowski-Górecki <[email-masked]>

[ Upstream commit 0f4558ae91870692ce7f509c31c9d6ee721d8cdc ]

This reverts commit 1f2565780e9b7218cf92c7630130e82dcc0fe9c2.

The 'hotplug-status' node should not be removed as long as the vif
device remains configured. Otherwise the xen-netback would wait for
re-running the network script even if it was already called (in case of
the frontent re-connecting). But also, it _should_ be removed when the
vif device is destroyed (for example when unbinding the driver) -
otherwise hotplug script would not configure the device whenever it
re-appear.

Moving removal of the 'hotplug-status' node was a workaround for nothing
calling network script after xen-netback module is reloaded. But when
vif interface is re-created (on xen-netback unbind/bind for example),
the script should be called, regardless of who does that - currently
this case is not handled by the toolstack, and requires manual
script call. Keeping hotplug-status=connected to skip the call is wrong
and leads to not configured interface.

More discussion at
https://lore.kernel.org/xen-devel/[email-masked]/T/#u

Signed-off-by: Marek Marczykowski-Górecki <[email-masked]>
Reviewed-by: Paul Durrant <[email-masked]>
Link: https://lore.kernel.org/r/[email-masked]
Signed-off-by: Jakub Kicinski <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/xen-netback/xenbus.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 78c56149559ce..6b678ab0a31f7 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -499,6 +499,7 @@ static void backend_disconnect(struct backend_info *be)
 		unsigned int queue_index;
 
 		xen_unregister_watchers(vif);
+		xenbus_rm(XBT_NIL, be->dev->nodename, "hotplug-status");
 #ifdef CONFIG_DEBUG_FS
 		xenvif_debugfs_delif(vif);
 #endif /* CONFIG_DEBUG_FS */
-- 
2.34.1