zfsbootcfg: use vfs.root.mountfrom and update nextboot on every vdev

[tsoome]

Summary

vfs.zfs.boot.primary_pool is only set on BIOS boot, use vfs.root.mountfrom
instead and update all vdevs on pool.

[allanjude]

sbin/zfsbootcfg/zfsbootcfg.c

44 ↗

(On Diff #72569)

We should change the naming throughout zfsbootcfg to call it 'bootonce', since 'nextboot' is a different feature, and this will get confusing when we combine the two

55 ↗

(On Diff #72569)

Instead of doing this here, we can use the new IOCTL from upstream where looping over and writing to each label is done inside the kernel

[allanjude]

As we progress here, we will want a switch to maintain the legacy behaviour, at least for a while. We might even decide not to change the default right away.

[tsoome]

sbin/zfsbootcfg/zfsbootcfg.c

55 ↗

(On Diff #72569)

yes, thats planned for next iteration.

[tsoome]

rename install_nextboot to install_bootonce

[allanjude]

Reviewed By: allanjude

[yuripv]

head/sbin/zfsbootcfg/zfsbootcfg.c

56

Shouldn't this be += as otherwise we'll return the status for the last child only?