summaryrefslogtreecommitdiff
path: root/functions/losetup.sh
blob: b221d37a4afec73fac08785bb0a35dc37c59aeca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
#!/bin/sh

## live-build(7) - System Build Scripts
## Copyright (C) 2016-2020 The Debian Live team
## Copyright (C) 2006-2015 Daniel Baumann <mail@daniel-baumann.ch>
##
## This program comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
## This is free software, and you are welcome to redistribute it
## under certain conditions; see COPYING for details.

Lodetach ()
{
	local DEVICE="${1}"
	local ATTEMPT="${2:-1}"

	if [ "${ATTEMPT}" -gt 3 ]
	then
		Echo_error "Failed to detach loop device '${DEVICE}'."
		exit 1
	fi

	# Changes to block devices result in uevents which trigger rules which in
	# turn access the loop device (ex. udisks-part-id, blkid) which can cause
	# a race condition. We call 'udevadm settle' to help avoid this.
	if command -v udevadm >/dev/null
	then
		udevadm settle
	fi

	# Loop back devices aren't the most reliable when it comes to writes.
	# We sleep and sync for good measure - better than build failure.
	sync
	sleep 1

        if [ "${LB_IMAGE_TYPE}" = "hdd" ];
        then
                case "${LB_BUILD_WITH_CHROOT}" in
                        true)
                                PARTITIONS=$(lsblk --raw --output "MAJ:MIN" --noheadings "${DEVICE}" | tail -n +2 | sort)
                                COUNTER=1
                                for i in $PARTITIONS; do
                                        if [ -e "chroot/${DEVICE}p${COUNTER}" ]
                                        then
                                                Chroot chroot "rm -f ${DEVICE}p${COUNTER}"
                                        fi
                                        if [ -e "${DEVICE}p${COUNTER}" ]
                                        then
                                                rm -f ${DEVICE}p${COUNTER}
                                        fi
                                        COUNTER=$((COUNTER + 1))
                                done
                                ;;

                        false)
                                PARTITIONS=$(lsblk --raw --output "MAJ:MIN" --noheadings "${DEVICE}" | tail -n +2 | sort)
                                COUNTER=1
                                for i in $PARTITIONS; do
                                        if [ -e "${DEVICE}p${COUNTER}" ]
                                        then
                                                rm -f ${DEVICE}p${COUNTER}
                                        fi
                                        COUNTER=$((COUNTER + 1))
                                done
                                ;;
                esac


        fi

        losetup -d "${DEVICE}" || Lodetach "${DEVICE}" "$(expr ${ATTEMPT} + 1)"
}

Losetup ()
{
	local DEVICE="${1}"
	local FILE="${2}"
	local PARTITION="${3:-1}"

	local FDISK_OUT
	local LOOPDEVICE
	losetup --read-only --partscan "${DEVICE}" "${FILE}"
	FDISK_OUT="$(fdisk -l -u ${DEVICE} 2>&1)"
	Lodetach "${DEVICE}"

	LOOPDEVICE="$(echo ${DEVICE}p${PARTITION})"

        if [ "${LB_IMAGE_TYPE}" = "hdd" ]
        then
                losetup --partscan "${DEVICE}" "${FILE}"
                case "${LB_BUILD_WITH_CHROOT}" in
                        true)
                                PARTITIONS=$(lsblk --raw --output "MAJ:MIN" --noheadings "${DEVICE}" | tail -n +2 | sort)
                                COUNTER=1
                                for i in $PARTITIONS; do
                                        MAJ=$(echo $i | cut -d: -f1)
                                        MIN=$(echo $i | cut -d: -f2)
                                        if [ ! -e "chroot/${DEVICE}p${COUNTER}" ]
                                        then
                                                Chroot chroot "mknod ${DEVICE}p${COUNTER} b $MAJ $MIN"
                                        fi
                                        if [ ! -e "${DEVICE}p${COUNTER}" ]
                                        then
                                                mknod ${DEVICE}p${COUNTER} b $MAJ $MIN
                                        fi
                                        COUNTER=$((COUNTER + 1))
                                done
                                ;;
        
                        false)
                                PARTITIONS=$(lsblk --raw --output "MAJ:MIN" --noheadings "${DEVICE}" | tail -n +2 | sort)
                                COUNTER=1
                                for i in $PARTITIONS; do
                                        MAJ=$(echo $i | cut -d: -f1)
                                        MIN=$(echo $i | cut -d: -f2)
                                        if [ ! -e "${DEVICE}p${COUNTER}" ]
                                        then
                                                mknod ${DEVICE}p${COUNTER} b $MAJ $MIN
                                        fi
                                        COUNTER=$((COUNTER + 1))
                                done
                                ;;
                esac
        else
        	if [ "${PARTITION}" = "0" ]
        	then
		Echo_message "Mounting %s with offset 0" "${DEVICE}"

        		losetup --partscan "${DEVICE}" "${FILE}"
        	else
        		local SECTORS
        		local OFFSET
        		SECTORS="$(echo "$FDISK_OUT" | sed -ne "s|^$LOOPDEVICE[ *]*\([0-9]*\).*|\1|p")"
        		OFFSET="$(expr ${SECTORS} '*' 512)"

        		Echo_message "Mounting %s with offset %s" "${DEVICE}" "${OFFSET}"

        		losetup --partscan -o "${OFFSET}" "${DEVICE}" "${FILE}"
        	fi
        fi
}

# adapted from lib/ext2fs/mkjournal.c, default block size is 4096 bytes (/etc/mke2fs.conf).
ext2fs_default_journal_size()
{
	local SIZE="$1"
	if [ "${SIZE}" -lt "8" ]; then # 2048*4096
		echo 0
	elif [ "${SIZE}" -lt "128" ]; then # 32768*4096
		echo 4
	elif [ "${SIZE}" -lt "1024" ]; then # 256*1024*4096
		echo 16
	elif [ "${SIZE}" -lt "2048" ]; then # 512*1024*4096
		echo 32
	elif [ "${SIZE}" -lt "4096" ]; then # 1024*1024*4096
		echo 64
	else
		echo 128
	fi
}

Calculate_partition_size_without_journal ()
{
	local WITHOUT_JOURNAL_ORIGINAL_SIZE="${1}"
	local WITHOUT_JOURNAL_FILESYSTEM="${2}"

	local PERCENT
	case "${WITHOUT_JOURNAL_FILESYSTEM}" in
		ext2|ext3|ext4)
			PERCENT="6"
			;;
		*)
			PERCENT="3"
			;;
	esac

	echo $(expr ${WITHOUT_JOURNAL_ORIGINAL_SIZE} + ${WITHOUT_JOURNAL_ORIGINAL_SIZE} \* ${PERCENT} / 100 + 1)
}

Calculate_partition_size ()
{
	local ORIGINAL_SIZE="${1}"
	local FILESYSTEM="${2}"

	case "${FILESYSTEM}" in
		ext3|ext4)
			local NON_JOURNAL_SIZE
			local PROJECTED_JOURNAL_SIZE
			local PROJECTED_PARTITION_SIZE
			local PRE_FINAL_PARTITION_SIZE
			local JOURNAL_SIZE
			NON_JOURNAL_SIZE=$(Calculate_partition_size_without_journal ${ORIGINAL_SIZE} ${FILESYSTEM})
			PROJECTED_JOURNAL_SIZE=$(ext2fs_default_journal_size ${NON_JOURNAL_SIZE})
			PROJECTED_PARTITION_SIZE=$(expr ${ORIGINAL_SIZE} + ${PROJECTED_JOURNAL_SIZE})
			PRE_FINAL_PARTITION_SIZE=$(Calculate_partition_size_without_journal ${PROJECTED_PARTITION_SIZE} ${FILESYSTEM})
			JOURNAL_SIZE=$(ext2fs_default_journal_size ${PRE_FINAL_PARTITION_SIZE})

			expr $(Calculate_partition_size_without_journal ${ORIGINAL_SIZE} ${FILESYSTEM}) + ${JOURNAL_SIZE}
			;;
		*)
			Calculate_partition_size_without_journal ${ORIGINAL_SIZE} ${FILESYSTEM}
			;;
	esac
}