pull replication seems ummount replicated dataset

20.12 PR: https://github.com/freenas/zettarepl/pull/125

so whole 

/mnt/pool0/perun.ninex.info/UNIX and all child datasets being unmounted during replication and not being mounted back.

Former user
after zfs mount -a
root@ATUIN:~ # zfs mount -a
root@ATUIN:~ # mount | grep perun
pool0/perun.ninex.info on /mnt/pool0/perun.ninex.info (zfs, local, noatime, nfsv4acls)
pool0/perun.ninex.info/UNIX/ROOT/12.2-RELEASE on /mnt/pool0/perun.ninex.info/ROOT/12.2-RELEASE (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX on /mnt/pool0/perun.ninex.info/UNIX (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/usr/home on /mnt/pool0/perun.ninex.info/usr/home (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/tmp on /mnt/pool0/perun.ninex.info/tmp (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/var/audit on /mnt/pool0/perun.ninex.info/var/audit (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/usr/ports on /mnt/pool0/perun.ninex.info/usr/ports (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/usr/src on /mnt/pool0/perun.ninex.info/usr/src (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/var/log on /mnt/pool0/perun.ninex.info/var/log (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/var/tmp on /mnt/pool0/perun.ninex.info/var/tmp (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/poudriere on /mnt/pool0/perun.ninex.info/UNIX/poudriere (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/var/crash on /mnt/pool0/perun.ninex.info/var/crash (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage on /mnt/pool0/perun.ninex.info/UNIX/iocage (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/var/mail on /mnt/pool0/perun.ninex.info/var/mail (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/releases on /mnt/pool0/perun.ninex.info/UNIX/iocage/releases (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/templates on /mnt/pool0/perun.ninex.info/UNIX/iocage/templates (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/images on /mnt/pool0/perun.ninex.info/UNIX/iocage/images (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/log on /mnt/pool0/perun.ninex.info/UNIX/iocage/log (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/download on /mnt/pool0/perun.ninex.info/UNIX/iocage/download (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/iwaniec.com.pl on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/iwaniec.com.pl (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/releases/12.1-RELEASE on /mnt/pool0/perun.ninex.info/UNIX/iocage/releases/12.1-RELEASE (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/poczta.ninex.info on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/poczta.ninex.info (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/ufopaedia.org on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/ufopaedia.org (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/releases/12.2-RELEASE on /mnt/pool0/perun.ninex.info/UNIX/iocage/releases/12.2-RELEASE (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/poligrafia.krakow.pl on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/poligrafia.krakow.pl (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/openxcom.org on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/openxcom.org (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/download/12.2-RELEASE on /mnt/pool0/perun.ninex.info/UNIX/iocage/download/12.2-RELEASE (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/ufoai.org on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/ufoai.org (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/nginx on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/nginx (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/poczta.ninex.info/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/poczta.ninex.info/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/iwaniec.com.pl/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/iwaniec.com.pl/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/poligrafia.krakow.pl/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/poligrafia.krakow.pl/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/ufoai.org/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/ufoai.org/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/releases/12.1-RELEASE/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/releases/12.1-RELEASE/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/nginx/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/nginx/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/releases/12.2-RELEASE/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/releases/12.2-RELEASE/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/ufopaedia.org/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/ufopaedia.org/root (zfs, local, noatime, read-only, nfsv4acls)
pool0/perun.ninex.info/UNIX/iocage/jails/openxcom.org/root on /mnt/pool0/perun.ninex.info/UNIX/iocage/jails/openxcom.org/root (zfs, local, noatime, read-only, nfsv4acls)

After new snapshot arrive:
root@ATUIN:~ # mount|grep perun
pool0/perun.ninex.info on /mnt/pool0/perun.ninex.info (zfs, local, noatime, nfsv4acls)
root@ATUIN:~ #

@Former user so what datasets are not mounted after the replication exactly? In your debug I see that everything that has a mountpoint is mounted.

Former user  this is done deliberetly.
to better explain: i am replicating whole DATASET from FreeBSD (Zroot with bootenv)
problem with that is a fact that childdataset name not always match mountpoint.
eg.
on Source system
dataset                                                           mountpoint        
UNIX/ROOT/12.2-RELEASE                                     /
UNIX/var                                                                 /var
UNIX/perun.ninex.info/UNIX/poudriere/ports       /UNIX/poudriere/ports
UNIX/poudriere/ports/default                               /usr/local/poudriere/ports/default
... etc.

so tahat create problem when you try to mount them into folders created from dataset name
as on original system UNIX/poudriere/ports is empty, not contain folder default/.
So on slave system as mountpoint not exist system try to create it (on readonly dataset (we are slave)) it will fail.
as those folders are empty, not used, those are only parent dataset...
to avoid mount errors i changed mountpoint of those empty to none.

How it looks on source system:

root@perun:~ # zfs list
NAME USED AVAIL REFER MOUNTPOINT
UNIX 218G 1.54T 88K /UNIX
UNIX/ROOT 16.6G 1.54T 88K none
UNIX/ROOT/12.2-RELEASE 16.6G 1.54T 12.9G /
UNIX/iocage 156G 1.54T 104K /UNIX/iocage
UNIX/iocage/download 402M 1.54T 88K /UNIX/iocage/download
UNIX/iocage/download/12.2-RELEASE 402M 1.54T 402M /UNIX/iocage/download/12.2-RELEASE
UNIX/iocage/images 88K 1.54T 88K /UNIX/iocage/images
UNIX/iocage/jails 152G 1.54T 96K /UNIX/iocage/jails
UNIX/iocage/jails/iwaniec.com.pl 17.1G 1.54T 104K /UNIX/iocage/jails/iwaniec.com.pl
UNIX/iocage/jails/iwaniec.com.pl/root 17.1G 1.54T 17.3G /UNIX/iocage/jails/iwaniec.com.pl/root
UNIX/iocage/jails/nginx 1.16G 1.54T 104K /UNIX/iocage/jails/nginx
UNIX/iocage/jails/nginx/root 1.16G 1.54T 1.44G /UNIX/iocage/jails/nginx/root
UNIX/iocage/jails/openxcom.org 16.9G 1.54T 104K /UNIX/iocage/jails/openxcom.org
UNIX/iocage/jails/openxcom.org/root 16.9G 1.54T 17.1G /UNIX/iocage/jails/openxcom.org/root
UNIX/iocage/jails/poczta.ninex.info 1.51G 1.54T 96K /UNIX/iocage/jails/poczta.ninex.info
UNIX/iocage/jails/poczta.ninex.info/root 1.51G 1.54T 1.79G /UNIX/iocage/jails/poczta.ninex.info/root
UNIX/iocage/jails/poligrafia.krakow.pl 2.95G 1.54T 104K /UNIX/iocage/jails/poligrafia.krakow.pl
UNIX/iocage/jails/poligrafia.krakow.pl/root 2.95G 1.54T 3.19G /UNIX/iocage/jails/poligrafia.krakow.pl/root
UNIX/iocage/jails/ufoai.org 106G 1.54T 104K /UNIX/iocage/jails/ufoai.org
UNIX/iocage/jails/ufoai.org/root 106G 1.54T 107G /UNIX/iocage/jails/ufoai.org/root
UNIX/iocage/jails/ufopaedia.org 5.70G 1.54T 104K /UNIX/iocage/jails/ufopaedia.org
UNIX/iocage/jails/ufopaedia.org/root 5.70G 1.54T 5.96G /UNIX/iocage/jails/ufopaedia.org/root
UNIX/iocage/log 124K 1.54T 124K /UNIX/iocage/log
UNIX/iocage/releases 3.77G 1.54T 88K /UNIX/iocage/releases
UNIX/iocage/releases/12.1-RELEASE 2.46G 1.54T 88K /UNIX/iocage/releases/12.1-RELEASE
UNIX/iocage/releases/12.1-RELEASE/root 2.46G 1.54T 1.24G /UNIX/iocage/releases/12.1-RELEASE/root
UNIX/iocage/releases/12.2-RELEASE 1.31G 1.54T 96K /UNIX/iocage/releases/12.2-RELEASE
UNIX/iocage/releases/12.2-RELEASE/root 1.31G 1.54T 1.31G /UNIX/iocage/releases/12.2-RELEASE/root
UNIX/iocage/templates 88K 1.54T 88K /UNIX/iocage/templates
UNIX/poudriere 2.31G 1.54T 88K /UNIX/poudriere
UNIX/poudriere/jails 1.31G 1.54T 88K /UNIX/poudriere/jails
UNIX/poudriere/jails/FreeBSD-12_2-RELEASE-amd64 1.31G 1.54T 1.31G /usr/local/poudriere/jails/FreeBSD-12_2-RELEASE-amd64
UNIX/poudriere/ports 1022M 1.54T 88K /UNIX/poudriere/ports
UNIX/poudriere/ports/default 1022M 1.54T 947M /usr/local/poudriere/ports/default
UNIX/tmp 768K 1.54T 176K /tmp
UNIX/usr 41.5G 1.54T 88K /usr
UNIX/usr/home 37.9G 1.54T 37.9G /usr/home
UNIX/usr/ports 2.88G 1.54T 2.88G /usr/ports
UNIX/usr/src 733M 1.54T 733M /usr/src
UNIX/var 1.26G 1.54T 88K /var
UNIX/var/audit 88K 1.54T 88K /var/audit
UNIX/var/crash 88K 1.54T 88K /var/crash
UNIX/var/log 1.26G 1.54T 840M /var/log
UNIX/var/mail 1.59M 1.54T 96K /var/mail
UNIX/var/tmp 88K 1.54T 88K /var/tmp