9447 NFS unmount is slow
Review Request #1064 - Created April 10, 2018 and submitted - Latest diff uploaded
This improves the speed of the NFS unmount in kernel for all NFS versions by introducing new linked list of rnodes in mntinfo so some functions used during the unmount operation does not need to walk through all rnodes in the rtable.
For unit test and its results please see https://www.illumos.org/issues/9447#note-2 The testing proved that the in-kernel NFS unmount functions are significantly faster with the new implementation in the tested scenarios. This fix is running in production for few weeks now with no regressions reported.