Modularize

3 files changed, 178 insertions, 0 deletions

diff --git a/modules/dev.inc b/modules/dev.inc
new file mode 100644
index 0000000..c2046d3
--- /dev/null
+++ b/modules/dev.inc
@@ -0,0 +1,49 @@
+#!/bin/ash
+
+# Get all partitions with given id (list of /dev/sdXX)
+# Works for MBR/DOS by looking at the type (1 byte)
+# and for GPT by looking for the label 'OpenSLX-ID$1'
+# in case an id was given, or with the given UUID,
+# or with the given name.
+# The output will be a list of matching devices,
+# sorted from largest to smallest.
+dev_find_partitions() {
+	local ID dev exp target
+	exp=
+	# target for the scan, defaults to /dev to check everything
+	if [ -b "$1" ]; then
+		target="$1"
+		shift
+	elif [ -d "$1" ]; then
+		target="$1/"
+	else
+		target="/dev/"
+	fi
+	while [ "$#" -gt 0 ]; do
+		ID="$1"
+		shift
+		[ -z "$ID" ] && continue
+		# if single digit, e.g. 7, look for 0x7 and 0x07
+		if regex_imatch "$ID" "^[0-9a-f]$"; then
+			ID="0?$ID"
+		fi
+
+		if regex_imatch "$ID" "^[0-9a-f?]{2,3}$"; then # Match two digit and the expanded three digit version from above
+			# if double digit look for MBR types and OpenSLX-ID$ID GPT labels
+			exp="$exp|ID_PART_ENTRY_(NAME=OpenSLX-ID|TYPE=0x)$ID"
+		elif regex_imatch "$ID" "^[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}$"; then
+			# if UUID, look for TYPE
+			exp="$exp|ID_PART_ENTRY_TYPE=$ID"
+		else
+			# something else, look for names of partitions / filesystems
+			ID="$( regex_escape "$ID" )"
+			exp="$exp|ID_(PART_ENTRY_NAME|FS_LABEL)=$ID"
+		fi
+	done
+	exp="${exp:1}"
+	for dev in $(find $target* -type b); do
+		udevadm info --name="$dev" | grep -iqE "($exp)\$" \
+			&& printf "%s\n" "$(blockdev --getsize64 "$dev") $dev"
+	done | sort -n -k1 -r | cut -d' ' -f2
+}
+
diff --git a/modules/fs/path.inc b/modules/fs/path.inc
new file mode 100644
index 0000000..f3a041b
--- /dev/null
+++ b/modules/fs/path.inc
@@ -0,0 +1,112 @@
+#!/bin/ash
+
+DM_STATE_FILE="/run/openslx/dmsetup.state"
+readonly DM_STATE_FILE
+
+# Return the device corresponding to the given path, or
+# empty if it's not mounted from a device (tmpfs, cifs, ...)
+fs_path_getdev() {
+	local _dev
+	_dev="$( df -P "$1" | awk '$1 ~ "^/dev/" {print $1}' )"
+	[ -n "$_dev" ] || return 1
+	[ -b "$_dev" ] || return 1
+	printf "%s" "$_dev"
+}
+
+# Return base mount point of given path
+# eg. call with "/mnt/nfs/temp/data", returns "/mnt/nfs"
+fs_path_getmountpoint() {
+	local _mp
+	_mp="$( df -P "$1" | awk '$6 ~ "^/" {print $6}' )"
+	[ -n "$_mp" ] || return 1
+	[ -d "$_mp" ] || return 1
+	printf "%s" "$_mp"
+}
+
+# Get fstype of given directory
+fs_path_gettype() {
+	local _mp
+	_mp="$( df -P "$1" | awk '$6 ~ "^/" {print $6}' )"
+	[ -n "$_mp" ] || return 1
+	[ -d "$_mp" ] || return 1
+	awk '$2 == "'"$_mp"'" {print $3}' '/proc/mounts'
+}
+
+# Helper to check whether given directory resides in RAM, either
+# by being mounted as tmpfs or not mounted at all in which case
+# we assume the same. Returns 0 if so, 1 if otherwise backed,
+# 2 when errors occur.
+fs_path_isvolatile() {
+	[ -z "$1" ] && return 2
+	local _dev _mp
+	_dev="$(fs_path_getdev "$1")"
+	[ -z "$_dev" ] && return 0 # No result, assume tmpfs
+	[ "$_dev" = "${_dev#/dev/zram}" ] || return 0 # zram is in RAM, like tmpfs
+	[ "$_dev" != "${_dev#/dev/mapper/}" ] || return 1 # Doesn't start with /dev/mapper, assume some kind of storage
+	[ -s "$DM_STATE_FILE" ] || return 2 # No point in continuing
+	_mp="$(fs_path_getmountpoint "$1")"
+	[ -z "$_mp" ] && return 2
+	# it is a device mapper device, check if it was setup in dracut's initramfs.
+	grep -qE "^$( regex_escape "${_dev}" )\s+$( regex_escape "${_mp}" )\s+type=0" "$DM_STATE_FILE"
+}
+
+# Return free/total space at given path, in KiB.
+# If the given path is backed by a thin pool, snapshot, etc.
+# it returns a conservative estimate, considering the remaining
+# space of the backing device.
+# Returns "<free> <total>"
+fs_path_space() {
+	[ -z "$1" ] && return 1
+	local _free _total _dev _type _id _name _bs _tmp _tfree _ttotal
+	_type="$( fs_path_gettype "$1" )"
+	[ -z "$_type" ] && return 1
+	_free="$( df -P "$1" | awk '$6 ~ "^/" {print $4 " " $2}' )"
+	case "$_type" in # EASY!
+		tmpfs|nfs*|cifs)
+		printf "%s" "$_free"
+		return
+	esac
+	_dev="$( fs_path_getdev "$1" )"
+	if [ "$_dev" = "${_dev#/dev/mapper/}" ]; then # does *NOT* start with /dev/mapper, assume not device mapped
+		# In case we start using aufs again, check if it needs special handling...
+		printf "%s" "$_free"
+		return
+	fi
+	# Split, since we might need to do Min()
+	_total="${_free#* }"
+	_free="${_free% *}"
+	_type="$( dmsetup status "$_dev" | awk '{print $3}' )"
+	_tfree=0
+	_ttotal=0
+	case "$_type" in
+		snapshot)
+			# Field 4 is used/total in sectors of 512 byte, so divide by two for KiB
+			_tmp="$( dmsetup status "$_dev" | awk '{split($4, a, "/"); print (a[2] - a[1]) / 2 " " a[2] / 2}' )"
+			_tfree="${_tmp% *}"
+			_ttotal="${_tmp#* }"
+			;;
+		thin)
+			# Determine matching pool
+			_id="$( dmsetup table "$_dev" | awk '{print $4}' )"
+			if [ -n "$_id" ]; then
+				_name="$( cat "/sys/dev/block/${_id}/dm/name" )"
+				if [ -n "$_name" ]; then
+					# Get data block size (in sectors of 512 byte)
+					_bs="$( dmsetup table "$_name" | awk '{print $6}' )"
+					if [ "$_bs" -gt 0 ]; then
+						# Field 6 is used/total (in data blocks), so transform into KiB
+						_tmp="$( dmsetup status "$_name" | awk -v "bs=$_bs" '{split($6, a, "/"); print ((a[2] - a[1]) / 2) * bs " " (a[2] / 2) * bs}' )"
+						_tfree="${_tmp% *}"
+						_ttotal="${_tmp#* }"
+					fi
+				fi
+			fi
+			;;
+	esac
+	if [ "$_tfree" -ge 0 ] && [ "$_ttotal" -gt 0 ]; then
+		[ "$_tfree" -lt "$_free" ] && _free="$_tfree"
+		[ "$_ttotal" -lt "$_total" ] && _total="$_ttotal"
+	fi
+	printf "%s" "$_free $_total"
+}
+
diff --git a/modules/regex.inc b/modules/regex.inc
new file mode 100644
index 0000000..21c3d65
--- /dev/null
+++ b/modules/regex.inc
@@ -0,0 +1,17 @@
+#!/bin/ash
+
+# Match $1 against perl regex $2, case insensitive
+regex_imatch() {
+	printf "%s" "$1" | grep -qPi "$2"
+}
+
+# Escapes $1 for use in grep -E/-P, sed -r, etc.
+# Pass --slash to escape '/' too. (e.g. for sed)
+regex_escape() {
+	if [ "x$1" = "x--slash" ]; then
+		printf "%s" "$2" | sed 's,[][()\.^$?*+/],\\&,g'
+	else
+		printf "%s" "$1" | sed 's/[][()\.^$?*+]/\\&/g'
+	fi
+}
+