Currently the linking order of the infiniband, IB, modules decide in which
order the clients are attached and detached. For example one IB client may
use resources from another IB client. This can lead to a potential deadlock
at shutdown. For example if the ipoib is unregistered after the ib_multicast
client is detached, then if ipoib is using multicast addresses a deadlock may
happen, because ib_multicast will wait for all its resources to be freed before
returning from the remove method.
Fix this by using module_xxx_order() instead of module_xxx().
Differential Revision: https://reviews.freebsd.org/D23973
MFC after: 1 week
Sponsored by: Mellanox Technologies
ae68c844b6