[0/5] vhost-scsi: Fix management operation hangs

Message

Mike Christie Feb. 23, 2023, 12:19 a.m. UTC

The following patches were made over Linus tree and also apply over
mst tree's vhost branch. The patches fix an issue where management
operations like LUN mapping/unmapping and device addition hang for 30
seconds or up to N minutes depending on the device.

The problem is that we use a global mutex to protect the list of tpgs
but we hold that mutex during those management operations. So if you
are just trying to add another device, it will have to wait on another
device if we are in the middle of clearing it's endpoint and it's
waiting on hung IO.

This patchset fixes up the ordering of how we flush IO and release
refcounts so we don't need to always hold the mutex.