Added output to zpool online and offline

[rincebrain]

Motivation and Context

zpool online and zpool offline don't actually print any error information, they just set an error code and die.

That's not super useful for interactively noticing your command failed.

Description

^

How Has This Been Tested?

Isn't testing what CI is for?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Breaking change (fix or feature that would cause existing functionality to change)
• Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the OpenZFS code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• I have run the ZFS Test Suite with this change applied.
• All commit messages are properly formatted and contain Signed-off-by.

[stuartthebruce]

Will this also fix the silent stderr output for a failed zpool export, e.g.,

[root@node2259 ~]# cat /sys/module/zfs/version 
2.2.4-1

[root@node2259 ~]# zpool export test

[root@node2259 ~]# echo $?
1
[root@node2259 ~]# zpool status test
  pool: test
 state: SUSPENDED
status: One or more devices are faulted in response to IO failures.
action: Make sure the affected devices are connected, then run 'zpool clear'.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-HC
config:

	NAME        STATE     READ WRITE CKSUM
	test        ONLINE       0     0     0
	  sdo       ONLINE       0     0     0
	  sdp       ONLINE       0     0     0
	  sdq       ONLINE       3   464     0
	  sdr       ONLINE       0     0     0
	  sds       ONLINE       0     0     0

errors: 217 data errors, use '-v' for a list

Is there a hack to destroy this pool without rebooting? Note, the current error message for that is also misleading,

[root@node2259 ~]# zpool destroy -f test
could not destroy 'test': could not unmount datasets

[root@node2259 ~]# zfs list
no datasets available

[rincebrain]

No, but I could go do that.

As far as fixing the inability to do anything, go look at the forced export PR.

[behlendorf]

This just needs to be rebased on master. It looks like it based on master from Jan '24 which is why the Fedora builders failed.

[rincebrain]

Sure, I'm going to go see about convincing export to print errors for whatever case they hit and then rebase.