Illumos #3744
3744 zfs shouldn't ignore errors unmounting snapshots
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3744 illumos/illumos-gate@fc7a6e3fefc649cb65c8e2a35d194781445008b0
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
Porting notes:
- There is no clear way to distinguish between a failure when we tried to unmount the snapdir of a zvol (which does not exist) and the failure when we try to unmount a snapdir of a dataset, so the changes to zfs_unmount_snap() were dropped in favor of an altered Linux function that unconditionally returns 0.