For IO passthrough command, it uses an IO queue associated with the device. Actually, this patch does not modify that part.
This patch is not really focused on io queues; instead, it is more about namespace protection from other namespace's user ios. The patch here doesn't prevent a userÂsubmitting completely arbitraryÂcommands on IO queues. One still can
do it through a char dev file descriptor. However, when a userÂexplicitly chooses a namespace's file descriptor, it is unlikely that she/he tries to issue an io command to a different namespace. Maybe in that case someone should to
use a new admin command.