#!/usr/bin/env bash # # Script to back given read-only device using the block device # specified by SLX_WRITABLE_DEVICE_IDENTIFIER in the SLX config. # If SLX_WRITABLE_DEVICE_PARTITION_TABLE is sepcified, it will # further create device mapper devices accordingly. # # Example partition config: # # thin-snapshot root 10G 1 # thin-volume tmp 20G 0 # linear data0 5-10G 1 # linear data1 1-50% 1 # # NOTE: Encrypting thin-snapshot will actually encrypt the # entire pool data device used for the pool. # TODO: Support external keys # TODO: Put table in file in config.tgz type -p emergency_shell || . /lib/dracut-lib.sh # for debugging purposes exec {BASH_XTRACEFD}> /run/openslx/dmsetup.log set -x # read-only device to prepare for CoW [ -z "$1" ] && emergency_shell "Read-only device was not given!" declare -g read_only_device="$1" declare -g read_only_device_sz="$( blockdev --getsz "$1" )" # Use _sz suffix for sizes expressed in number of 512b sectors, # _size for random other crap declare -rg ntfs_list="/run/openslx/.thin-ntfs-candidates" # handle_unit # Supply percentage, or size in [kmgt]bytes, # returns appropriate value in number of 512b sectors handle_unit() { # default to bytes local -i potency=0 local -i val="$1" case "$2" in [%]) # These are relative to the writable CoW device # Allow > 100% for over-provisioning val="$(( remaining_device_sz * val / 100 ))" ;; [Kk]) potency=1 ;;& [Mm]) potency=2 ;;& [Gg]) potency=3 ;;& [Tt]) potency=4 ;;& *) # => 1024 ** potency for G, M, K, etc results in bytes # => bytes / 512 = sectors val=$(( val * ( 1024 ** potency) / 512 )) ;; esac echo "$val" } parse_config() { local remaining_device_sz="$writable_device_sz" parse_config_int "$1" 0 parse_config_int "$1" 1 } # global array variables storing the configuration of the partitions declare -ag linear snapshot thin_snapshot thin_volume parse_config_int() { [ -z "$1" ] && return 1 local -i rel_only="$2" while IFS= read -r line || [ -n "$line" ]; do [ -z "$line" ] && continue read -r type name range crypt ignore <<< "$line" type=${type//-/_} # to use the type as variable in eval if ! [[ "$type" =~ \ ^(linear|snapshot|thin_snapshot|thin_volume)$ ]]; then echo "$0: Ignoring invalid type: $line" continue fi if [[ -z "$name" ]]; then echo "$0: Ignoring nameless entry: $line" continue fi unset min_unit max_unit min max # ranges can be like: 40G, 40-80G, 10G-20% if ! [[ "$range" =~ ^([0-9]+)([GgMmKkBb%]?)(-([0-9]+)([GgMmKkBb%]?))?$ ]]; then echo "$0: Ignoring invalid range: $line" continue fi local min="${BASH_REMATCH[1]}" local max="${BASH_REMATCH[4]:-${BASH_REMATCH[1]}}" local min_unit="${BASH_REMATCH[2]:-${BASH_REMATCH[5]}}" local max_unit="${BASH_REMATCH[5]:-${BASH_REMATCH[2]}}" # first pass we handle absolute values unly, second pass relative ones if [[ "$min_unit" = "%" || "$max_unit" = "%" ]]; then [ "$rel_only" != 1 ] && continue else [ "$rel_only" = 1 ] && continue fi if [ -z "$min_unit" ]; then echo "$0: WARNING: No unit given in range, assuming BYTES: $line" fi min="$( handle_unit "$min" "$min_unit" )" max="$( handle_unit "$max" "$max_unit" )" if (( min > max )); then # So, we might end up with something like 30G-100%, but the writable device # is only 20GB. In that case we most likely want to contine, and not consider # this an error. So let's try to come up with some logic on what is an error # and what isn't. Probably anything involving a mix of percentage and # non-percentage should not be an error. if [[ "$min_unit" = "%" && "$max_unit" != "%" ]] \ || [[ "$min_unit" != "%" && "$max_unit" = "%" ]]; then # Let's hope for the best max="$min" else echo "$0: Ignoring invalid range (min > max): $line" continue fi fi if ! [[ "$crypt" =~ ^[01]$ ]]; then echo "$0: Disabling encryption due to invalid crypt argument: $line" crypt=0 fi # finally save it to the global array for this type case "$type" in linear) linear+=("${name} ${crypt} ${min} ${max}") ;; snapshot) snapshot+=("${name} ${crypt} ${min} ${max}") ;; thin_snapshot) thin_snapshot+=("${name} ${crypt} ${min} ${max}") ;; thin_volume) thin_volume+=("${name} ${crypt} ${min} ${max}") ;; *) echo "$0: SOMETHING NOT GOOT CHECK SOURCE CODE" ;; esac # Decrease for upcoming calculations if we used fixed values here if [ "$rel_only" != 1 ]; then (( remaining_device_sz -= ( min + max ) / 2 )) fi done <<< "$1" } # Helper to call 'dmsetup setup' without syncing with udev # and then actively create the devices with the mknodes command. # Either pass the table contents as $2, or pipe them into the function # dmsetup_create_noudevsync [table] dmsetup_create_noudevsync() { ( set -eo pipefail if [ -n "$2" ]; then printf "%s\n" "$2" | dmsetup create "$1" --noudevsync else dmsetup create "$1" --noudevsync fi dmsetup mknodes --noudevsync "$1" ) local ret=$? [ -b "/dev/mapper/$1" ] || ret=99 [ $ret -ne 0 ] && dmsetup remove --noudevsync "$1" return $ret } # encrypt_device [ ] encrypt_device() { # TODO: Send key back to us, demand ransom modprobe dm-crypt || echo "$0: dm-crypt loading failed, maybe builtin?" [ -b "$1" ] || return 1 [ -n "$2" ] || return 1 local dev_size="$( blockdev --getsz "$1" )" if [ -z "$dev_size" ]; then echo "$0: Cannot encrypt non-existent device $1" return 1 fi local size="$4" local start="$3" # Sanitize [ "$start" -ge 0 ] 2> /dev/null || start=0 [ "$size" -gt 0 ] 2> /dev/null || size="$dev_size" # Put in bounds (( start > dev_size )) && start="$dev_size" (( start + size > dev_size )) && size="$(( dev_size - start ))" local key key="$( < /dev/urandom xxd -c32 -p -l32 )" [ -z "$key" ] && key="$( < /dev/urandom tr -c -d 'a-f0-9' | dd count=1 bs=32 )" [ -z "$key" ] && key="$( < /dev/urandom head -c32 | xxd -c32 -p )" [ -z "$key" ] && key="$( < /dev/urandom xxd -c32 -p | head -n 1 )" if [ -z "$key" ]; then echo "$0: ERROR: Could not generate encryption key" return 1 fi if ! dmsetup_create_noudevsync "$2" \ "0 ${size} crypt aes-xts-plain64 $key 0 $1 ${start} 1 allow_discards"; then echo "$0: Failed to encrypt $1." return 1 fi return 0 } # create_snapshot " " create_snapshot() { modprobe dm-snapshot || echo "$0: dm-snapshot loading failed, maybe builtin?" read -r name persist ignore <<< "$1" if ! dmsetup_create_noudevsync "$name" \ "0 $read_only_device_sz snapshot $read_only_device $writable_device ${persist:-N} 8"; then echo "$0: Failed to create snapshot on '$writable_device' for '$read_only_device'." return 1 fi return 0 } # This function is called if no ID44 partition could be found or anoother kind # of critical error occurs during the CoW layer setup. It will combine the # the read-only device with a DM zero device to increase its virtual size # by half the RAM size. A sparse file of that size will then be created and # placed on a dedicated tmpfs. # THIS FUNCTION MUST NEVER RETURN ramdisk_fallback() { echo "$0: Falling back to regular dm-snapshot on a RAMdisk." # RAM size in kb, note that this is equal to half # of the entire RAM when interpreted as 512-bytes sectors. local ram_cow_sz="$(awk '/^MemTotal:/ { printf("%d\n", $2 ); exit }' /proc/meminfo)" # try to prepare the zero extension device local extended_device="/dev/mapper/${read_only_device##*/}-extended" ( set -e lsmod | grep -q dm-zero || modprobe dm-zero dmsetup_create_noudevsync "${extended_device##*/}" \ "0 $read_only_device_sz linear $read_only_device 0 $read_only_device_sz $ram_cow_sz zero" ) local ret="$?" if [ "$ret" -eq 0 ]; then read_only_device="$extended_device" read_only_device_sz="$(( read_only_device_sz + ram_cow_sz ))" else echo "$0: Failed to setup the fake larger '$read_only_device'." echo "$0: Continuing with its original size." fi # prepare dedicated tmpfs mount point local cow_tmpfs="/run/openslx/cow" if ! mkdir -p "$cow_tmpfs"; then cow_tmpfs="${cow_tmpfs}.$$.$RANDOM" mkdir -p "$cow_tmpfs" fi if ! mount -t tmpfs cow-tmpfs -o size="$(( read_only_device_sz / 2 + 100 ))k" "$cow_tmpfs"; then echo "$0: Failed to mount tmpfs in '$cow_tmpfs' of size '$(( read_only_device_sz / 2 + 100 ))KiB', trying to use regular /run tmpfs." fi # create sparse file there local file="$cow_tmpfs/thinpool.meta" if ! truncate -s "$(( read_only_device_sz * 512 ))" "$file" \ && ! dd if=/dev/null of="$file" seek="$read_only_device_sz" bs=512 2> /dev/null; then emergency_shell "Failed to allocate CoW file $file." fi declare -rg writable_device="$( losetup --show --find "$file" )" local cow_device_candidate="root" while [ -b "/dev/mapper/$cow_device_candidate" ]; do cow_device_candidate="root.$RANDOM" done if [ -z "$writable_device" ] || ! create_snapshot "$cow_device_candidate N"; then emergency_shell "CRITICAL: failed to setup RAMdisk fallback." exit 1 fi finish_setup "$cow_device_candidate" "0" "$read_only_device_sz" } # finish_setup [] # is the device name only, /dev/mapper will be prepended automatically. # denotes if the created device lies in a RAMdisk (0) or is backed by a disk (1). # is given in sectors. # THIS FUNCTION MUST NEVER RETURN finish_setup() { if [ -z "$1" ] || ! [ -b "/dev/mapper/$1" ]; then emergency_shell "'/dev/mapper/$1' not a block device. Failed to setup CoW layer." exit 1 fi if ! [[ "$2" =~ ^[0-9]$ ]]; then emergency_shell "'$2' not a valid type, 0 or 1 expected." fi # optional? { echo "# Generated by '$0'." echo "SLX_DNBD3_DEVICE_COW=/dev/mapper/$1" } >> /etc/openslx save_partition_info "$1" "/" "$2" "$3" exit 0 } # path to save the achieved setup to declare -rg partitions_config="/run/openslx/dmsetup.state" cat <<-EOF > "$partitions_config" # Generated by '$0'. # Format: # Options can be: # * type -> CoW layer type: 0 is RAMdisk, 1 is disk, 2 is network # * size -> in 512 byte sectors EOF # save_partition_info [] save_partition_info() { [ -b "/dev/mapper/$1" ] || return 1 [ -n "$2" ] || return 1 [[ "$3" =~ ^[0-9]$ ]] || return 1 local opts="type=$3" # plain size given [[ "$4" =~ ^[0-9]+$ ]] && opts="$opts,physical_size=$4" # - [[ "$4" =~ ^[0-9]+-[0-9]+$ ]] && opts="$opts,shared_physical_size=${4%-*},virtual_size=${4#*-}" echo "/dev/mapper/$1 $2 ${opts}" >> "$partitions_config" } # This will create another dm-linear on top of $scratch_device in case its # size differs from $scratch_device_sz. This is useful for setups where you # cannot explicitly configure how much space to use from the underlying device, # and the partition table says not to use the entire $writable_device for cow require_exact_scratch_size() { local current_sz="$( blockdev --getsz "$scratch_device" )" (( current_sz == scratch_device_sz )) && return 0 # Everything fine if (( current_sz < scratch_device_sz )); then echo "$0: WARNING: scratch_device_sz is larger than actual device." echo "$0: This should never happen." scratch_device_sz="$current_sz" return 0 fi # We could check if $scratch_device already is a dm target, and just adjust its # size, but I think that scenario isn't possible, currently. if ! dmsetup_create_noudevsync "scratch" "0 $scratch_device_sz linear $scratch_device 0"; then echo "$0: Failed to create scratch space for the CoW layer." return 1 fi scratch_device="/dev/mapper/scratch" save_partition_info "scratch" "*" "1" "$scratch_device_sz" return 0 } create_pool() { declare -r data_block_sz=256 # Desired Block size (number of 512byte sectors) declare -r wanted_low_mb=100 # Free space below this will trigger a dm event # create external snapshot for read-only device # create remaining thin volumes modprobe dm-thin-pool || echo "$0: dm-thin-pool load failed, maybe builtin?" # create temporary metadata device # calculate number of sectors needed and check boundaries: # XXX Formula from thin-pool.txt calculates size in *bytes*, we want 512b blocks metadata_dev_sz="$(( 48 * scratch_device_sz / data_block_sz / 512 ))" # If we want NTFS as a backup plan to extend the pool, check if the current size # is less than 100GB, and only then consider this feature. # Maybe make that thresold configurable one day, but the the desktop client # use case this is sensible for now. if [ "$SLX_NTFSFREE" = "backup" ] && (( scratch_device_sz < 209715200 )) \ && [ -z "$metadata_persistent" ]; then find_ntfs_partitions if [ -s "$ntfs_list" ]; then # Look what size we end up if we want at least 50GB local sum="$( awk -v sum=0 \ '{sum+=$1; if (sum >= 104857600) exit}END{printf "%.0f", sum}' \ "$ntfs_list" )" if (( sum > 0 )); then (( sum > 209715200 )) && sum=209715200 # Max 100GB # Account for this potential growth in the metadata device size for future expansion metadata_dev_sz="$(( metadata_dev_sz + 48 * sum / data_block_sz / 512 ))" echo "$sum" > "/run/openslx/.thin-ntfs-growsize" root_ntfs_extra="$sum" fi fi fi # Min 2MB -> 4096 sectors, max 16GB -> 33554432 sectors [ "$metadata_dev_sz" -lt 4096 ] && metadata_dev_sz="4096" # TODO handle the exotic case of a too large metadata device to fit within RAM. [ "$metadata_dev_sz" -gt 33554432 ] && metadata_dev_sz="33554432" local scratch_device_offset=0 local metadata_dev= local metadata_persistent= if [ -n "$metadata_persistent" ]; then # create persistent slice of the writable device for the pool metadata if ! dmsetup_create_noudevsync "pool-metadata" \ "0 $metadata_dev_sz linear $scratch_device $scratch_device_offset"; then echo "$0: Failed to create linear device for pool metadata device." else # Adjust size for pool-data down accordingly scratch_device_offset="$metadata_dev_sz" scratch_device_sz=$(( scratch_device_sz - metadata_dev_sz )) declare -r metadata_dev="/dev/mapper/pool-metadata" # TODO configurable wipe: dd if=/dev/zero of="$metadata_dev" count=1 bs=4096 # TODO: If we fail later on in this function, we would actually have to destroy # this target again, and re-adjust the offset and size back, so that the # snapshot fallback would work properly. Or maybe just don't support fallback. fi fi if [ -z "$metadata_dev" ]; then # create RAMdisk in /run for metadata device metadata_dev="$(mktemp -p /run/openslx .pool-metadata.XXX)" # Create sparse file of required size dd if=/dev/null of="$metadata_dev" bs=512 seek="$metadata_dev_sz" 2> /dev/null declare -r metadata_dev="$( losetup --show --find "$metadata_dev" )" fi if [ -z "$metadata_dev" ]; then echo "$0: Could not set up persistent or tmpfs-loop metadata device. Aborting." return 1 fi local pool_data_dev if (( root_ntfs_extra == 0 )) && (( scratch_device_offset == 0 )); then # No offset, no potential expansion, don't create another linear target pool_data_dev="$scratch_device" else pool_data_dev="/dev/mapper/pool-data" # Create linear device of the writable device, in case we have an offset from # the on-disk meta data. Also this way we can easily extend it later. if ! dmsetup_create_noudevsync "${pool_data_dev##*/}" \ "0 $scratch_device_sz linear $scratch_device $scratch_device_offset"; then echo "$0: Failed to create pool data device on '$scratch_device'." return 1 fi fi local low_water_mark # Convert MB to blocks low_water_mark=$(( wanted_low_mb * 2048 / data_block_sz )) if ! dmsetup_create_noudevsync "${pool_dev##*/}" \ "0 $scratch_device_sz thin-pool $metadata_dev $pool_data_dev $data_block_sz $low_water_mark 1 skip_block_zeroing"; then echo "$0: Failed to create thin-pool device (meta: $metadata_dev, data: $pool_data_dev)" return 1 fi return 0 } # create_volume [backing_dev] create_volume() { if [ -z "$pool_dev" ] || ! [ -b "$pool_dev" ]; then echo "$0: Global pool device not set or present." return 1 fi if [ $# -lt 3 ] || [ -z "$1" ]; then echo "$0: create_volume: not enough arguments." return 1 fi local name="$1" local id="$2" local size="$3" local backing_dev="$4" # Optional, internal if empty if ! dmsetup message "$pool_dev" 0 "create_thin $id"; then echo "$0: Failed to create thin volume with id '$id' in pool '$pool_dev'." echo "$0: It might already exists, trying anyway..." fi if ! dmsetup_create_noudevsync "$name" "0 $size thin $pool_dev $id $backing_dev"; then echo "$0: Failed to create external snapshot named '$name':" echo " Size: $size" echo " Backing device: $backing_dev" echo " Thin volume id: $id" return 1 fi return 0 } # Find NTFS partitions with decently sized ranges of # free space. We can use these as our writable layer # for our thin-pool, if configured. # If suitable, this will create the file $ntfs_list with # one line per suitable partition, format # total_size_blocks devpath # Results are sorted by size, descending order find_ntfs_partitions() { [ -z "$SLX_NTFSFREE" ] && return [ "$SLX_NTFSFREE" = "never" ] && return [ -e "$ntfs_list" ] && return if ! command -v ntfsfree &> /dev/null; then echo "$0: ntfsfree not found, cannot use NTFS partitions as RW layer" return fi local part sum ro dev ntfs_extra_space_sz=0 for part in /dev/disk/by-partuuid/*; do # Skip empty/ro devices dev="$( readlink -f "$part" )" dev="${dev##*/}" ro="$( cat "/sys/class/block/${dev}/ro" )" [ "$ro" = 1 ] && continue # Only count ranges >= 256MB, sum will be in number of 512b blocks sum="$( ntfsfree --block-size 512 --min-size "$(( 256 * 1024 * 1024 ))" "$part" 2> /dev/null \ | awk -v sum=0 '{if ($1 == "Range") sum += $4}END{printf "%.0f", sum}' )" # Only consider volume if sum of these ranges > 1GB (this is BLOCKS, not bytes) (( "$sum" > 2 * 1024 * 1024 )) || continue echo "$sum $part" # only thing in loop going to stdout (( ntfs_extra_space_sz += sum )) done | sort -nr > "$ntfs_list" } ntfs_extra_space_sz=0 ### ## MAIN ### . /etc/openslx . slx-tools # "Preload" functions by executing them NOT in a subshell dev_find_partitions &> /dev/null dev_swap_version &> /dev/null # This is the main variable driving this script declare -g id44_crypted= declare -g writable_device= if [ -z "$SLX_WRITABLE_DEVICE_IDENTIFIER" ]; then SLX_WRITABLE_DEVICE_IDENTIFIER=("44" "87f86132-ff94-4987-b250-444444444444") # TODO make scripts reading this variable compatible with list of IDs echo "SLX_WRITABLE_DEVICE_IDENTIFIER='${SLX_WRITABLE_DEVICE_IDENTIFIER[0]}'" >> /etc/openslx echo "SLX_WRITABLE_DEVICE_IDENTIFIERS='${SLX_WRITABLE_DEVICE_IDENTIFIER[*]}'" >> /etc/openslx fi # XXX The fuck? This may or may not be an array? Shit will defintely break some day... if [ -n "$SLX_WRITABLE_DEVICE_IDENTIFIER" ]; then declare -a writable_devices writable_devices=( $( dev_find_partitions "${SLX_WRITABLE_DEVICE_IDENTIFIER[@]}" ) ) if [[ "${#writable_devices[@]}" -eq 0 && "$SLX_NTFSFREE" != "never" ]] || [ "$SLX_NTFSFREE" = "always" ]; then find_ntfs_partitions fi if [ -s "$ntfs_list" ] || [[ "${#writable_devices[@]}" -gt 1 ]]; then # More than one device, and/or NTFS space, need linear tbl="/run/openslx/dmsetup-linear-id44" pos=0 grow_max_sz=9999999999 for dev in "${writable_devices[@]}"; do max="$(( grow_max_sz - pos ))" (( max <= 0 )) && break sz="$( blockdev --getsz "$dev" )" (( sz > 0 )) || continue (( sz > max )) && sz="$max" echo "$pos $sz linear $dev 0" (( pos += sz )) done > "$tbl" if [ -s "$ntfs_list" ]; then sum= while read -r sum dev _ || [ -n "$sum" ]; do # each dev word= while read -r word range_start_b _ range_sz _ || [ -n "$word" ]; do # each slice of dev [ "$word" = "Range" ] || continue (( range_sz > 0 )) || continue slice_sz="$(( grow_max_sz - pos ))" (( slice_sz <= 0 )) && break (( slice_sz > range_sz )) && slice_sz="$range_sz" # Append line if echo "$pos $slice_sz linear $dev $range_start_b" >> "$tbl"; then # Update counter (( pos += slice_sz )) else echo "$0: Could not write new table row into $tbl" fi done < <( ntfsfree --block-size 512 --min-size "$(( 256 * 1024 * 1024 ))" "$dev" ) done < "$ntfs_list" # Don't try to add NTFS space again later SLX_NTFSFREE="never" sed -i "s/^SLX_NTFSFREE.*$/# & # disabled in stage3\nSLX_NTFSFREE='never'/" "/etc/openslx" rm -f -- "$ntfs_list" fi # See if we need a linear target at all if ! [ -s "$tbl" ]; then echo "$0: Empty tmp/id44 table, fallback to RAM" elif [ "$( wc -l < "$tbl" )" -eq 1 ] && [[ "${#writable_devices[@]}" -ge 1 ]]; then # Only one line, have writable device -> use directly writable_device="${writable_devices[0]}" else # set up linera device if ! dmsetup_create_noudevsync "id44-group" < "$tbl"; then echo "$0: Error creating group of id44 devices. Fallback to RAM :-(" else writable_device="/dev/mapper/id44-group" fi fi else # Single device writable_device="${writable_devices[0]}" fi fi if [ -z "$writable_device" ]; then echo "$0: Could not find writable device with id '$SLX_WRITABLE_DEVICE_IDENTIFIER'." ramdisk_fallback elif is_on "$SLX_ID44_CRYPT"; then # Config option crypts the entire ID44 device(s), before any slices are taken from it. if encrypt_device "$writable_device" "id44-crypt"; then echo "$0: ID44 encrypted" writable_device="/dev/mapper/id44-crypt" # Remember the whole device is already encrypted, and ignore the crypt flag for the partition table later id44_crypted=1 else echo "$0: Error encrypting ID44 partition" fi fi # NOTE: from here on out, every value related to size is in 512 bytes sectors! declare -rg writable_device_sz="$( blockdev --getsz "$writable_device" )" # If SLX_WRITABLE_DEVICE_PARTITION_TABLE is not set, just do # regular thin-snapshot for the CoW layer, else parse it. if [ -z "$SLX_WRITABLE_DEVICE_PARTITION_TABLE" ]; then SLX_WRITABLE_DEVICE_PARTITION_TABLE="thin-snapshot root 100% 0" fi # extra swap? if grep -qFw 'slx.swap' "/proc/cmdline"; then # Only if our basic writable_device is large enough, or we have ntfs backup do_swap_sz=0 if (( writable_device_sz > 80078125 )); then # more than ~40GB, go ahead do_swap_sz="$(( ( writable_device_sz - 70312500 ) / 2 ))" # cap to 6GB (( do_swap_sz > 11718750 )) && do_swap_sz=11718750 elif [ "$SLX_NTFSFREE" = "backup" ] \ && (( ntfs_extra_space_sz > 70312500 )) && (( writable_device_sz > 11718750 )); then # more than 40GB NTFS backup space, more than 6GB ID44, make 4GB swap do_swap_sz=7812500 fi # Check how many we have and if they're regular, unencrypted ones. # If it's plenty, don't cut out swap from our backing device swap_sz=0 for part in $( dev_find_partitions "82" "0657fd6d-a4ab-43c4-84e5-0933c84b4f4f" ); do dev_swap_version "$part" &> /dev/null || continue this_sz="$( blockdev --getsz "$part" )" (( this_sz > 0 )) && (( swap_sz += this_sz )) done echo "Have existing swap of $swap_sz blocks" # Go ahead with swap? Only if existing swap < 4GB. If so, add line to table. if (( do_swap_sz > 0 )) && (( swap_sz < 7812500 )); then echo "Adding $do_swap_sz blocks of additional swap on backing dev" skb="$(( do_swap_sz / 2 ))" SLX_WRITABLE_DEVICE_PARTITION_TABLE="$( printf "%s\n%s" "linear slx-swap ${skb}K 0" \ "$SLX_WRITABLE_DEVICE_PARTITION_TABLE" )" fi fi parse_config "$SLX_WRITABLE_DEVICE_PARTITION_TABLE" # Default to thin-snapshot, if none were configured if [ "${#snapshot[@]}" = 0 ] && [ "${#thin_snapshot[@]}" = 0 ]; then parse_config "thin-snapshot root 100% 0" fi # Sanity checks for weird configurations # XXX These were declared array and now turn into strings... if [ "${#snapshot[@]}" -gt 1 ]; then echo "Multiple snapshots specified, using first one: ${snapshot[0]}" fi snapshot="${snapshot[0]}" if [ "${#thin_snapshot[@]}" -gt 1 ]; then echo "Multiple thin-snapshots specified, using first one: ${thin_snapshot[0]}" fi thin_snapshot="${thin_snapshot[0]}" if [ -n "$snapshot" ] && [ -n "$thin_snapshot" ]; then echo "$0: Both snapshot and thin-snapshot specified, prefering thin-snapshot." snapshot= fi ### ## LINEAR SLICES ### # start allocating spaces to the configured devices declare -g writable_device_used_sz=0 # first, reserve the space for the rootfs cow snapshot (of either type)... # (this is the first line of our custom partition table) read -r name crypt min max ignore <<< "${thin_snapshot:-${snapshot}}" declare -g scratch_device="/dev/mapper/scratch" declare -gi scratch_device_sz=0 if (( min <= writable_device_sz )); then scratch_device_sz="$max" (( scratch_device_sz > writable_device_sz )) && scratch_device_sz="$writable_device_sz" else # minimum snapshot size is bigger than physical device size echo "$0: Minimum snapshot size is too big for the scratch partition." echo "$0: You probably need to use a more conservative value." echo "$0: Using this client maximum scratch space ($writable_device_sz sectors)." scratch_device_sz="$writable_device_sz" fi if (( scratch_device_sz == writable_device_sz )); then # Only one, use directly, maybe crypt if [ -z "$id44_crypted" ] && [ "$crypt" -ne 0 ]; then if ! encrypt_device "$writable_device" "${scratch_device##*/}" 0 "$scratch_device_sz"; then echo "$0: Continuing with unencrypted scratch" scratch_device="$writable_device" fi else # Noop scratch_device="$writable_device" fi else # Smaller slice requested, device mapper to the rescure # Round down to 4k border, so next slice won't be misaligned if we're on a 4k sector disk scratch_device_sz="$(( (scratch_device_sz / 8) * 8 ))" # encrypt the scratch device, if configured if [ -z "$id44_crypted" ] && (( crypt != 0 )) \ && ! encrypt_device "$writable_device" "${scratch_device##*/}" 0 "$scratch_device_sz"; then echo "$0: Continuing with unencrypted scratch" crypt=0 # So we do the linear thing below fi if (( crypt == 0 )) && ! dmsetup_create_noudevsync "${scratch_device##*/}" \ "0 $scratch_device_sz linear $writable_device $writable_device_used_sz"; then echo "$0: Failed to create scratch space for the CoW layer." # this should never fail, but if it does, we would likely not be able to use # $writable_device for any dmsetup stuff, so just fallback to ramdisk # until we have a better idea on what to do :) ramdisk_fallback fi fi save_partition_info "${scratch_device##*/}" "*" "1" "$scratch_device_sz" writable_device_used_sz="$scratch_device_sz" # setup linear slices of the writable device for line in "${linear[@]}"; do [ -z "$line" ] && continue read -r name crypt min max ignore <<< "$line" [ -n "$id44_crypted" ] && crypt=0 free_space="$(( writable_device_sz - writable_device_used_sz ))" if [ "$min" -gt "$free_space" ]; then echo "$0: Not enough space left for linear devices: '$line' - have $free_space sectors" break fi # allocate its max if it fits within the free space, otherwise use the space left. to_allocate="$max" (( to_allocate > free_space )) && to_allocate="$free_space" # as above, round down to align on 4k sector devices to_allocate="$(( (to_allocate / 8) * 8 ))" if (( crypt != 0 )) \ && ! encrypt_device "$writable_device" "${name}" "$writable_device_used_sz" "$to_allocate"; then echo "$0: Failed to encrypt '$name', continuing without encryption." crypt=0 fi if (( crypt == 0 )) && ! dmsetup_create_noudevsync \ "$name" "0 $to_allocate linear $writable_device $writable_device_used_sz"; then echo "$0: Failed to create linear device: $line" continue fi # TODO sane? save_partition_info "$name" "*" "1" "$to_allocate" writable_device_used_sz=$(( to_allocate + writable_device_used_sz )) done ### ## THIN-PROVISIONING ### declare -rg pool_dev="/dev/mapper/pool" declare -gi root_ntfs_extra=0 # Extra blocks to provision to root fs for later expansion # Now decide what to do for the writable layer if [ -n "$thin_snapshot" ] || [ -n "$thin_volume" ]; then if ! create_pool ; then echo "Failed to create thin pool. Will ignore:" echo -e "\tThin snapshot: $(declare -p thin_snapshot)" echo -e "\tThin volumes: $(declare -p thin_volume)" echo "Trying snapshot fallback..." snapshot="$thin_snapshot" else # the order in which pool devices are created does not matter # so start with thin volumes starting with id 2 and end with # the thin-snapshot with id 1 which needs to call finish_setup. volume_id=2 # go over thin-volumes for line in "${thin_volume[@]}"; do [ -z "$line" ] && continue read -r name crypt min max ignore <<< "$line" [ -n "$id44_crypted" ] && crypt=0 # thin-volume can be created with max size, # since they are overprovisioned anyway. suffix= (( crypt != 0 )) && suffix="-k" if ! create_volume "$name$suffix" "$(( volume_id++ ))" "$max"; then echo "Failed to create thin volume '$name'." fi if (( crypt != 0 )) && ! encrypt_device \ "/dev/mapper/$name$suffix" "$name" 0 "$max"; then echo "Failed to encrypt thin volume '$name', continuing without encryption." name="$name$suffix" fi save_partition_info "$name" "*" "1" "${scratch_device_sz}-${max}" done if [ -n "$thin_snapshot" ]; then # create thin-snapshot, use first one read -r name crypt min max ignore <<< "$thin_snapshot" [ -n "$id44_crypted" ] && crypt=0 # min/max was used for the pool data device, ignore it here! # Calculate how much of the CoW space we reserve for changes in the base # system. Usually all the files in the base system should be static, but # if someone decided to run apt dist-upgrade, this would change a lot of # existing blocks, which is bad. # Use MIN( readonly_size / 2, scratch_size / 10 ) # until we come up with anything better. # Given an RO image of 10GB, this gives us: # 40GB scratch -> 46GB, so initially 36GB free space # 5GB scratch -> 14.5GB, initially 4.5GB free space declare -r max_reserved_sz="$(( scratch_device_sz / 10 ))" reserved_sz="$(( read_only_device_sz / 2 ))" (( reserved_sz > max_reserved_sz )) && reserved_sz="$max_reserved_sz" thin_snapshot_sz="$(( scratch_device_sz + read_only_device_sz - reserved_sz ))" # For later on-demand growing, overprovision by free space we found on # clean NTFS volumes. This requires a user-space helper to listen for # dm events in stage4, which should in turn add that free space to the pool-data if (( root_ntfs_extra > 0 )); then thin_snapshot_sz="$(( thin_snapshot_sz + root_ntfs_extra ))" fi suffix= (( crypt != 0 )) && suffix="-k" if ! create_volume "$name$suffix" 1 "$thin_snapshot_sz" "$read_only_device"; then echo "Failed to create external snapshot for '$read_only_device'." ramdisk_fallback fi if (( crypt != 0 )) && ! encrypt_device \ "/dev/mapper/$name$suffix" "$name" 0 "$thin_snapshot_sz"; then echo "Failed to encrypt thin volume '$name', continuing without encryption." name="$name$suffix" fi finish_setup "$name" "1" "$thin_snapshot_sz" fi echo "$0: Thin volumes defined, but no snapshot. Using tmpfs." ramdisk_fallback fi fi ### ## SNAPSHOT (OLD FUNCTIONALITY) ### if [ -n "$snapshot" ] && require_exact_scratch_size; then read -r name crypt min max ignore <<< "$snapshot" [ -n "$id44_crypted" ] && crypt=0 if ! create_snapshot "$name $persist"; then echo "Failed to create regular snapshot for '$read_only_device' on '$scratch_device'." else finish_setup "$name" "1" "$scratch_device_sz" fi fi # ultimate fallback ramdisk_fallback exit 1