K 10
svn:author
V 6
kevans
K 8
svn:date
V 27
2019-01-21T02:57:57.784642Z
K 7
svn:log
V 1535
MFC r342903, r342911: libbe(3)/bectl(8) refactor and fix mount for deep BEs

r342903: libbe(3): move altroot augmentation bits around a little bit

We could perhaps have a method that does this given a dataset, but it's yet
clear that we'll always want to bypass the altroot when we grab the
mountpoint. For now, we'll refactor things a bit so we grab the altroot
length when libbe is initialized and have a common method that does the
necessary augmentation (replace with / if it's the root, return a pointer to
later in the string if not).

This will be used in some upcoming work to make be_mount work properly for
deep BEs.

r342911: libbe(3): Change be_mount to mount/unmount child datasets

This set of changes is geared towards making bectl respect deep boot
environments when they exist and are mounted. The deep BE composition
functionality (`bectl add`) remains disabled for the time being. This set of
changes has no effect for the average user. but allows deep BE users to
upgrade properly with their current setup.

libbe(3): Open the target boot environment and get a zfs handle, then pass
that with the target mountpoint to be_mount_iter; If the BE_MNT_DEEP flag is
set call zfs_iter_filesystems and mount the child datasets.

Similar logic is employed when unmounting the datasets, save for children
are unmounted first.

bectl(8): Change bectl_cmd_jail to pass the BE_MNT_DEEP flag when
calling be_mount as well as call be_unmount when cleaning up after the
jail has exited instead of umount(2) directly.

PR:		234795

END