EXTRA_PATCHES=  ${.CURDIR}/files/extra-patch-periodic:skip-property+clean_snapshots-per_dataset:-p0

--- etc/periodic/zfs-snapshot.orig	2016-01-05 01:44:44.000000000 +0100

+++ etc/periodic/zfs-snapshot	2021-03-27 00:23:26.179216000 +0000

@@ -3,6 +3,7 @@

 # take the appropriately named snapshot

 create_snapshot()

 {

+    local _skip _inherited

     pool=$1

     case "$type" in

@@ -28,7 +29,7 @@

     # enumerate datasets under this pool or dataset, skip excluded datasets if requested

     if [ -n "$skip" ]; then

-            egrep="($(echo $skip | sed "s/ /|/g"))"

+            egrep="($(echo $skip | sed -E "s/[[:blank:]]+/|/g"))"

             datasets=$(zfs list -r -H -o name $pool | egrep -v "$egrep")

     else

             datasets=$(zfs list -r -H -o name $pool)

@@ -36,9 +37,41 @@

     # loop through datasets, do snapshots of each

     for dataset in $datasets; do

+        # skip datasets with mountpoint property set to "none", these usually

+        # don't contain data but are used for properties inheritance only.

+        if zfs get -H -o value mountpoint $dataset 2>/dev/null | grep -q "^none"

+        then

+            echo "     mountpoint property of $dataset is "none", skipping..."

+            continue

+        fi

+        _skip=$(zfs get -H -o value periodic:skip $dataset 2>/dev/null \

+                                                           | tr '[:blank:]' ',')

+        # check current dataset for user property periodic:skip

+        if [ X${_skip} != X- ]; then

+          _inherited="$(zfs get -H -o source periodic:skip $dataset 2>/dev/null\

+                                                        | grep -o "^inherited")"

+          # values of al(l|ways), true, 1, on, always, yes indicate that 

+          # no snapshot is wanted - for children aswell - and indipendent of

+          # $type, while $type match does only exclude for the current type.

+          if echo ${_skip} | grep -qiE "(^|,)$type"; then

+            echo -n "     periodic:skip property of $dataset"

+            echo " ${_inherited:-matches} \"$type\", skipping..."

+            continue

+          elif echo ${_skip} | grep -qiE -e "^(al|true|1|on|yes)"; then

+            echo -n "     periodic:skip property of $dataset"

+            echo " ${_inherited:-matches} \"$_skip\", skipping..."

+            continue

+          fi

+        elif [ X${_skip} != X${_skip#base*} ] && [ -z "${_inherited}" ]; then

+          # value of "base" has to be ignored if user property was inherited,

+          # otherwise skip current dataset indipendently of $type

+            echo -n "     periodic:skip property of $dataset matches"

+            echo  " \"base\", skipping..."

+            continue

+        fi

         snapshot="$dataset@$now"

         # look for an existing snapshot with this name

-        if zfs list $snapshot > /dev/null 2>&1; then

+        if [ -n "$(zfs list -H -o name $snapshot 2>/dev/null)" ]; then

             echo "     snapshot $snapshot already exists, skipping..."

         else

             echo "     taking snapshot: $snapshot"

@@ -51,12 +84,7 @@

 delete_snapshot()

 {

     snapshot=$1

-    echo "     destroying old snapshot, $snapshot"

-    if ! echo $snapshot | grep -q @; then

-        # refuse to destroy something that doesn't look like a snapshot

-        echo >&2 "     aborting: not a snapshot: $snapshot"

-        exit 1

-    fi

+    echo "	destroying old snapshot, $snapshot"

     zfs destroy -r $snapshot

 }

@@ -68,55 +96,65 @@

     type=$3

     skip=$4

-    # create the regex matching the type of snapshots we're currently working

-    # on

-    case "$type" in

-        hourly)

-        # hourly-2009-01-01-00

-        regex="^$pool@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]-[0-9][0-9]$"

-        ;;

-        daily)

-        # daily-2009-01-01

-        regex="^$pool@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]$"

-        ;;

-        weekly)

-        # weekly-2009-01

-        regex="^$pool@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]"

-        ;;

-        monthly)

-        # monthly-2009-01

-        regex="^$pool@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]"

-        ;;

-        yearly)

-        # yearly-2009

-        regex="^$pool@$type-[0-9][0-9][0-9][0-9]"

-        ;;

-        *)

-        echo "unknown snapshot type: $type"

-        exit 1

-    esac

-

     create_snapshot $pool $type

+    clean_snapshots $pool $type

+}

-    # get a list of all of the snapshots of this type sorted alpha, which

-    # effectively is increasing date/time

-    # (using sort as zfs's sort seems to have bugs)

-    snapshots=`zfs list -H -o name -t snapshot | sort | grep $regex`

-    # count them

-    count=`echo $snapshots | wc -w`

-    if [ $count -ge 0 ]; then

-        # how many items should we delete

-        delete=`expr $count - $keep`

-        count=0

-        # walk through the snapshots, deleting them until we've trimmed deleted

-        for snapshot in $snapshots; do

-            if [ $count -ge $delete ]; then

-                break

-            fi

-            delete_snapshot $snapshot

-            count=`expr $count + 1`

-        done

-    fi

+clean_snapshots()

+{

+    pool=$1

+

+    # loop through datasets, do look for number of snapshots each

+    for dataset in $datasets; do

+

+        # create the regex matching the type of snapshots we're currently working 

+        # on

+        case "$type" in

+            hourly)

+            # hourly-2009-01-01-00

+            regex="^$dataset@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]-[0-9][0-9]$"

+            ;;

+            daily)

+            # daily-2009-01-01

+            regex="^$dataset@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]$"

+            ;;

+            weekly)

+            # weekly-2009-01

+            regex="^$dataset@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]"

+            ;;

+            monthly)

+            # monthly-2009-01

+            regex="^$dataset@$type-[0-9][0-9][0-9][0-9]-[0-9][0-9]"

+            ;;

+            yearly)

+            # yearly-2009

+            regex="^$dataset@$type-[0-9][0-9][0-9][0-9]"

+            ;;

+            *)

+            echo "unknown snapshot type: $type"

+            exit 1

+        esac

+

+        # get a list of all of the snapshots of this type sorted alpha, which

+        # effectively is increasing date/time

+        # (using sort as zfs's sort seems to have bugs)

+        snapshots=`zfs list -H -o name -t snapshot | sort | grep $regex`

+        # count them

+        count=`echo $snapshots | wc -w`

+        if [ $count -ge 0 ]; then

+            # how many items should we delete

+            delete=`expr $count - $keep`

+            count=0

+            # walk through the snapshots, deleting them until we've trimmed deleted

+            for snapshot in $snapshots; do

+                if [ $count -ge $delete ]; then

+                    break

+                fi

+                delete_snapshot $snapshot

+                count=`expr $count + 1`

+            done

+        fi

+    done

 }

 # take snapshots of type, for pools, keeping keep old ones,

@@ -130,6 +168,12 @@

     echo ""

     echo "Doing zfs $type snapshots:"

     for pool in $pools; do

-        do_pool $pool $keep $type "$skip"

+        # Add top/parent dataset to $skip if pool is defiend with trailing /

+        if [ "${pool%/}" != "${pool}" ]; then

+            pool=${pool%/}

+            do_pool $pool $keep $type "${pool}\$${skip:+ ${skip}}"

+        else

+            do_pool $pool $keep $type "$skip"

+        fi

     done

 }

#

# Maintain ZFS snapshots with sysutils/zfs-periodic

#

# periodic(8) settings defining hourly run by cron(8)

#

# periodic(8) doesn't run hourly by default, /etc/crontab needs to be extended:

#                                 (exapmle is representing business hours only!)

### Perform ([extended-]business) hourly maintenance [zfs-periodic].

##13  7,9-13,15-17,19,21  *  *  1-6     root    periodic hourly

#

# We want "hourly" snapshots, which represents the type of periodic handling.

# We want "weekly" snapshots

weekly_zfs_snapshot_skip="/_entities/jails/\. /netshares/Groups$ /netshares$ /netshares/scratch /.backups"

# We want "monthly" snapshots

monthly_zfs_snapshot_skip="/_entities/jails/\. /netshares/Groups$ /netshares$ /netshares/scratch /.backups"

# As of a481121, "yearly" snapshots ar supported too

#yearly_zfs_snapshot_enable="YES"

#yearly_zfs_snapshot_pools="hostP0/ hostP1/"

#yearly_zfs_snapshot_keep=1

#yearly_zfs_snapshot_skip="/_entities/jails/\. /netshares/Groups$ /netshares$ /netshares/scratch /.backups"