I sent out an e-mail on 2020/01/21 with a plan to do this to Kyle, Rob, and
Wes; all parties have responded in the affirmative that it's OK to drop it
from these files.
This is the half of the changes required that work as-is with both in-tree
ZFS and the new hotness, sysutils/openzfs. Highlights are less dependency
on header pollution (from somewhere) and using 'mnttab' instead of
'extmnttab'. In the in-tree ZFS, the latter is a #define for the former,
but in the port extmnttab is actually a distinct struct that's a super-set
of mnttab. We really want mnttab here anyways, so just use it.
Add an undocumented -r option preceding the bectl subcommand to specify a BE
root to operate out of. This will remain undocumented for now, as some
caveats apply:
- BEs cannot be activated in the pool that doesn't contain the rootfs
- bectl create cannot work out of the box without the -e option right now,
since it defaults to the rootfs and cross-pool cloning doesn't work like
that (IIRC)
Plumb the BE root through to libbe(3) so that some things -can- be done to
it, e.g.
bectl -r tank/ROOT create -e default upgrade
bectl -r tank/ROOT mount upgrade /mnt
this aides in some upgrade setups where rootfs is not necessarily ZFS, and
also makes it easier/possible to regression-test bectl when combined with a
file-backed zpool.
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D18029
libbe(3) currently uses zfs_be_root and locates which of its children is
currently mounted at "/". This is reasonable, but not correct in the case of
a chroot, for two reasons:
- chroot root may be of a different zpool than zfs_be_root
- chroot root will not show up as mounted at "/"
Fix both of these by rewriting libbe_init to work from the rootfs down.
zfs_path_to_zhandle on / will resolve to the dataset mounted at the new
root, rather than the real root. From there, we can derive the BE root/pool
and grab the bootfs off of the new pool. This does no harm in the average
case, and opens up bectl to operating on different pools for scenarios where
one may be, for instance, updating a pool that generally gets re-rooted into
from a separate UFS root or zfs bootpool.
While here, I've also:
- Eliminated the check for /boot and / to be on the same partition. This
leaves one open to a setup where /boot (and consequently, kernel/modules)
are not included in the boot environment. This may very well be an
intentional setup done by someone that knows what they're doing, we should
not kill BE usage because of it.
- Eliminated the validation bits of BEs and snapshots that enforced
'mountpoint' to be "/" -- this broke when trying to operate on an imported
pool with an altroot, but we need not be this picky.
Reported by: philip
Reviewed by: philip, allanjude (previous version)
Tested by: philip
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D18012
Some paths through be_exists will set the error state, others will not
There are multiple reasons that a call can fail, so clean it up a bit: all
paths now return an appropriate error code so the caller can attempt to
distinguish between a BE legitimately not existing and just having the wrong
mountpoint. The caller is expected to bubble the error through to the
internal error handler as needed.
This fixes some unfriendliness with bectl(8)'s activate subcommand, where
it might fail due to a bad mountpoint but the only message output is a
generic "failed to activate" message.
Approved by: re (gjb)
- File names don't necessarily need to be repeated
- Add SPDX tags
- Add a missing copyright for Kyle Kneitinger in bectl.8, originally written
by him in GSoC 2017; his standard copyright notice has been copied from
other files within the same directory to remain consistent with how he
clearly wished to portray it
This makes the be_exists behavior match the comments that assert that we've
already checked that the dataset derived from the BE name is set to mount at
/.
Other changes of note:
- bectl_list sees another change; changing mountpoint based on mount status
turns out to be a bad idea, so instead make the mounted property of the
returned nvlist the path that it's mounted at
- Always return the "mountpoint" property in "mountpoint" if it's ste
be_get_dataset_snapshots has been added to libbe(3), effectively returning
the same information as be_get_bootenv_props but for snapshots of the given
dataset. The assumption is that one will have the BE dataset name before
wanting to grab snapshots.
This also accomplishes the following:
- Proxy through zfs_nicenum as be_nicenum, because it looks better than
humanize_number and would presumably be useful to other libbe consumers.
- Rename be_get_snapshot_props to be_get_dataset_props, make it more useful
At a bare minimum, this function will return 0 if a BE is mounted at the
given path or non-zero otherwise. If the optional 'details' nvlist is
supplied, it is filled with an nvpair containing just the information about
the BE mounted at the path. This nvpair is structured just as it is for
be_get_bootenv_props, except limited to just the single mount point.
Based on the idea that we shouldn't have all-new library and utility going
into base that need WARNS=1...
- Decent amount of constification
- Lots of parentheses
- Minor other nits
For the moment, this is a primitive nvlist dump of what we get back from
be_get_bootenv_props as a proof-of-concept and to make sure that we're
getting back the kind of information we want to see from list.
- Rename 'active' to 'rootfs', which is used in other places to describe the
currently booted (or about to be booted) BE.
- Add 'bootfs', which indicates the next boot environment to be booted. This
is pulled from the BOOTFS zpool property.
- Go ahead and keep an open handle to the active zpool. We might need to
enumerate datasets, get properties, and set properties (e.g. bootfs)
throughout other libbe bits, and a single handle isn't overly expensive.
