Michael Brown
e890d6083f
[ Upstream commit2afeec08ab] The logic in connect() is currently written with the assumption that xenbus_watch_pathfmt() will return an error for a node that does not exist. This assumption is incorrect: xenstore does allow a watch to be registered for a nonexistent node (and will send notifications should the node be subsequently created). As of commit1f2565780("xen-netback: remove 'hotplug-status' once it has served its purpose"), this leads to a failure when a domU transitions into XenbusStateConnected more than once. On the first domU transition into Connected state, the "hotplug-status" node will be deleted by the hotplug_status_changed() callback in dom0. On the second or subsequent domU transition into Connected state, the hotplug_status_changed() callback will therefore never be invoked, and so the backend will remain stuck in InitWait. This failure prevents scenarios such as reloading the xen-netfront module within a domU, or booting a domU via iPXE. There is unfortunately no way for the domU to work around this dom0 bug. Fix by explicitly checking for existence of the "hotplug-status" node, thereby creating the behaviour that was previously assumed to exist. Signed-off-by: Michael Brown <mbrown@fensystems.co.uk> Reviewed-by: Paul Durrant <paul@xen.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.