On Tue, Dec 22, 2020 at 06:24:09PM +0100, Hannes Reinecke wrote: > However, lookup_bdev() now always recurses into the filesystem, causing > multipath to stall in an all-paths-down scenario. I have not read the background about whatever the new problem is - I'm jumping in cold seeing this message - but from the very beginning of device-mapper we have strongly recommended that userspace supplies the block device in the form MAJOR:MINOR and all our own tools do that. We guarantee not to deadlock in these places when this is done. We also accept the device in the form of a path name as we know there are times when this is safe and convenient, but then we offer no guarantees - we place the responsibility upon userspace only to do this when it knows it is safe to do so i.e. no race and no deadlock. Alasdair