nixos-installer/lib/setup-scripts/zfs.sh

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## Creates all of the system's ZFS pools that are »createDuringInstallation«, plus their datasets.
function create-zpools { # 1: mnt
local poolName ; for poolName in "@{!config.wip.fs.zfs.pools[@]}" ; do
if [[ ! @{config.wip.fs.zfs.pools!catAttrSets.createDuringInstallation[$poolName]} ]] ; then continue ; fi
create-zpool "$1" "$poolName"
done
}
## Creates a single of the system's ZFS pools and its datasets.
function create-zpool { # 1: mnt, 2: poolName
local mnt=$1 ; local poolName=$2
eval 'local -A pool='"@{config.wip.fs.zfs.pools[$poolName]}"
eval 'local -a vdevs='"${pool[vdevArgs]}"
eval 'local -A poolProps='"${pool[props]}"
eval 'local -A dataset='"@{config.wip.fs.zfs.datasets[${pool[name]}]}"
eval 'local -A dataProps='"${dataset[props]}"
local dummy ; get-zfs-crypt-props "${dataset[name]}" dataProps dummy dummy
local -a zpoolCreate=( ) ; keySrc=/dev/null
if [[ ${dataProps[keyformat]:-} == ephemeral ]] ; then
dataProps[encryption]=aes-256-gcm ; dataProps[keyformat]=hex ; dataProps[keylocation]=file:///dev/stdin ; keySrc=/dev/urandom
fi
local name ; for name in "${!poolProps[@]}" ; do zpoolCreate+=( -o "${name}=${poolProps[$name]}" ) ; done
local name ; for name in "${!dataProps[@]}" ; do zpoolCreate+=( -O "${name}=${dataProps[$name]}" ) ; done
local index ; for index in "${!vdevs[@]}" ; do
part=${vdevs[$index]} ; if [[ $part =~ ^(mirror|raidz[123]?|draid[123]?.*|spare|log|dedup|special|cache)$ ]] ; then continue ; fi
if [[ @{config.boot.initrd.luks.devices!catAttrSets.device[$part]:-} ]] ; then
vdevs[$index]=/dev/mapper/$part
else
part=/dev/disk/by-partlabel/$part ; vdevs[$index]=$part
if ! is-partition-on-disks "$part" "${blockDevs[@]}" ; then echo "Partition alias $part used by zpool ${pool[name]} does not point at one of the target disks ${blockDevs[@]}" 1>&2 ; \return 1 ; fi
fi
done
@{native.kmod}/bin/modprobe zfs || true
<$keySrc @{native.xxd}/bin/xxd -l 32 -c 64 -p | ( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zpool create "${zpoolCreate[@]}" -R "$mnt" "${pool[name]}" "${vdevs[@]}" ) || return
if [[ $keySrc == /dev/urandom ]] ; then @{native.zfs}/bin/zfs unload-key "$poolName" &>/dev/null ; fi
prepend_trap "@{native.zfs}/bin/zpool export '$poolName'" EXIT || return
ensure-datasets $mnt '^'"$poolName"'($|[/])' || return
if [[ ${args[debug]:-} ]] ; then @{native.zfs}/bin/zfs list -o name,canmount,mounted,mountpoint,keystatus,encryptionroot -r "$poolName" ; fi
}
## Ensures that the system's datasets exist and have the defined properties (but not that they don't have properties that aren't defined).
# The pool(s) must exist, be imported with root prefix »$mnt«, and (if datasets are to be created or encryption roots to be inherited) the system's keystore must be open (see »mount-keystore-luks«) or the keys be loaded.
# »keystatus« and »mounted« of existing datasets should remain unchanged, newly crated datasets will not be mounted but have their keys loaded.
function ensure-datasets {( set -eu # 1: mnt, 2?: filterExp
if (( @{#config.wip.fs.zfs.datasets[@]} == 0 )) ; then \return ; fi
local mnt=$1 ; while [[ "$mnt" == */ ]] ; do mnt=${mnt:0:(-1)} ; done # (remove any tailing slashes)
local filterExp=${2:-'^'}
local tmpMnt=$(mktemp -d) ; trap "rmdir $tmpMnt" EXIT
local zfs=@{native.zfs}/bin/zfs
: 'Step-through is very verbose and breaks the loop, disabling it for this function' ; trap - debug
local name ; while IFS= read -u3 -r -d $'\0' name ; do
if [[ ! $name =~ $filterExp ]] ; then printf 'Skipping dataset »%s« since it does not match »%s«\n' "$name" "$filterExp" >&2 ; continue ; fi
eval 'local -A dataset='"@{config.wip.fs.zfs.datasets[$name]}"
eval 'local -A props='"${dataset[props]}"
local explicitKeylocation=${props[keylocation]:-} cryptKey cryptRoot
get-zfs-crypt-props "${dataset[name]}" props cryptKey cryptRoot
if $zfs get -o value -H name "${dataset[name]}" &>/dev/null ; then # dataset exists: check its properties
if [[ ${props[mountpoint]:-} ]] ; then # don't set the current mount point again (no-op), cuz that fails if the dataset is mounted
local current=$($zfs get -o value -H mountpoint "${dataset[name]}") ; current=${current/$mnt/}
if [[ ${props[mountpoint]} == "${current:-/}" ]] ; then unset props[mountpoint] ; fi
fi
if [[ ${props[keyformat]:-} == ephemeral ]] ; then
cryptRoot=${dataset[name]} ; unset props[keyformat] ; props[keylocation]=file:///dev/null
fi
if [[ $explicitKeylocation ]] ; then props[keylocation]=$explicitKeylocation ; fi
unset props[encryption] ; unset props[keyformat] # can't change these anyway
local propNames=$( IFS=, ; echo "${!props[*]}" )
local propValues=$( IFS=$'\n' ; echo "${props[*]}" )
if [[ $propValues != "$( $zfs get -o value -H "$propNames" "${dataset[name]}" )" ]] ; then
local -a zfsSet=( ) ; local propName ; for propName in "${!props[@]}" ; do zfsSet+=( "${propName}=${props[$propName]}" ) ; done
( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zfs set "${zfsSet[@]}" "${dataset[name]}" ) || return
fi
if [[ $cryptRoot && $($zfs get -o value -H encryptionroot "${dataset[name]}") != "$cryptRoot" ]] ; then ( # inherit key from parent (which the parent would also already have done if necessary)
if [[ $($zfs get -o value -H keystatus "$cryptRoot") != available ]] ; then
$zfs load-key -L file://"$cryptKey" "$cryptRoot" || exit ; trap "$zfs unload-key $cryptRoot || true" EXIT
fi
if [[ $($zfs get -o value -H keystatus "${dataset[name]}") != available ]] ; then
$zfs load-key -L file://"$cryptKey" "${dataset[name]}" || exit # will unload with cryptRoot
fi
( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zfs change-key -i "${dataset[name]}" ) || exit
) || return ; fi
else ( # create dataset
if [[ ${props[keyformat]:-} == ephemeral ]] ; then
props[encryption]=aes-256-gcm ; props[keyformat]=hex ; props[keylocation]=file:///dev/stdin ; explicitKeylocation=file:///dev/null
declare -a zfsCreate=( ) ; for name in "${!props[@]}" ; do zfsCreate+=( -o "${name}=${props[$name]}" ) ; done
{ </dev/urandom tr -dc 0-9a-f || true ; } | head -c 64 | ( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zfs create "${zfsCreate[@]}" "${dataset[name]}" ) || exit
$zfs unload-key "${dataset[name]}" || exit
else
if [[ $cryptRoot && $cryptRoot != ${dataset[name]} && $($zfs get -o value -H keystatus "$cryptRoot") != available ]] ; then
$zfs load-key -L file://"$cryptKey" "$cryptRoot" || exit
trap "$zfs unload-key $cryptRoot || true" EXIT
fi
declare -a zfsCreate=( ) ; for name in "${!props[@]}" ; do zfsCreate+=( -o "${name}=${props[$name]}" ) ; done
( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zfs create "${zfsCreate[@]}" "${dataset[name]}" )
fi
if [[ ${props[canmount]} != off ]] ; then (
mount -t zfs -o zfsutil "${dataset[name]}" $tmpMnt && trap "umount '${dataset[name]}'" EXIT &&
chmod 000 "$tmpMnt" && chown "${dataset[uid]}:${dataset[gid]}" -- "$tmpMnt" && chmod "${dataset[mode]}" -- "$tmpMnt"
) || exit ; fi
if [[ $explicitKeylocation && $explicitKeylocation != "${props[keylocation]:-}" ]] ; then
( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zfs set keylocation="$explicitKeylocation" "${dataset[name]}" ) || exit
fi
$zfs snapshot -r "${dataset[name]}"@empty || exit
) || return ; fi
eval 'local -A allows='"${dataset[permissions]}"
for who in "${!allows[@]}" ; do
# »zfs allow $dataset« seems to be the only way to view permissions, and that is not very parsable -.-
( PATH=@{native.zfs}/bin ; ${_set_x:-:} ; zfs allow -$who "${allows[$who]}" "${dataset[name]}" >&2 ) || return
done
done 3< <( printf '%s\0' "@{!config.wip.fs.zfs.datasets[@]}" | LC_ALL=C sort -z )
)}
## Given the name (»datasetPath«) of a ZFS dataset, this deducts crypto-related options from the declared keys (»config.wip.fs.keystore.keys."zfs/..."«).
function get-zfs-crypt-props { # 1: datasetPath, 2?: name_cryptProps, 3?: name_cryptKey, 4?: name_cryptRoot
local hash=@{config.networking.hostName!hashString.sha256:0:8}
local keystore=/run/keystore-$hash
local -n __cryptProps=${2:-props} ; local -n __cryptKey=${3:-cryptKey} ; local -n __cryptRoot=${4:-cryptRoot}
local name=$1 ; {
if [[ $name == */* ]] ; then local pool=${name/\/*/}/ ; local path=/${name/$pool/} ; else local pool=$name/ ; local path= ; fi
} ; local key=${pool/-$hash'/'/}$path # strip hash from pool name
__cryptKey='' ; __cryptRoot=''
if [[ @{config.wip.fs.keystore.keys[zfs/$name]:-} ]] ; then
if [[ @{config.wip.fs.keystore.keys[zfs/$name]} == unencrypted ]] ; then
__cryptProps[encryption]=off # empty key to disable encryption
else
__cryptProps[encryption]=aes-256-gcm ; __cryptProps[keyformat]=hex ; __cryptProps[keylocation]=file://"$keystore"/zfs/"$name".key
__cryptKey=$keystore/zfs/$name.key ; __cryptRoot=$name
fi
else
while true ; do
name=$(dirname $name) ; if [[ $name == . ]] ; then break ; fi
if [[ @{config.wip.fs.keystore.keys[zfs/$name]:-} ]] ; then
if [[ @{config.wip.fs.keystore.keys[zfs/$name]} != unencrypted ]] ; then
__cryptKey=$keystore/zfs/$name.key ; __cryptRoot=$name
fi ; break
fi
done
fi
}