[archiso] Add optional OverlayFS support

This is the first attemp to test overlayfs in archiso.
The current dm-snapshot mode is keep and is enabled by default,
while the new mode is enabled via "-s sfs" to mkarchiso.
No new boot parameters are added, since archiso hooks detects
if the .sfs file is for dm-snapshot (airootfs.img inside)
or for overlayfs.
Persistence is supported in overlayfs mode using the same options
(cowlabel or cowdevice), but warning while in dm-snapshot mode,
only one file is used (airootfs.cow), in overlayfs mode internal
files for workdir/ and upperdir/ are allocated, so you can not use
VFAT or NTFS.

To test this, you need to enable [testing] in pacman.conf from
releng profile and edit build.sh then add "-s sfs" in make_prepare()

Look at:
    setarch ${arch} mkarchiso ${verbose} -w "${work_dir}" -D "${install_dir}" prepare
Replace with:
    setarch ${arch} mkarchiso ${verbose} -w "${work_dir}" -s sfs -D "${install_dir}" prepare

The build requires just half of space that the build for dm-snapshot,
since there is no ext4 img ;)

Just to remember: there is no space gain in .sfs (just about 2M)

There is at least one thing during boot with machine-id service:
Dec 24 03:31:39 archiso systemd-machine-id-commit[183]: Failed to unmount transient /etc/machine-id file in our private namespace: Invalid argument

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386@gmail.com>
This commit is contained in:
Gerardo Exequiel Pozzi 2015-01-27 14:37:05 -03:00
parent fe29d5f334
commit a637bdb857
3 changed files with 47 additions and 6 deletions

View File

@ -1,5 +1,5 @@
# args: source, newroot, mountpoint # args: source, newroot, mountpoint
_mnt_fs() { _mnt_dmsnapshot() {
local img="${1}" local img="${1}"
local newroot="${2}" local newroot="${2}"
local mnt="${3}" local mnt="${3}"
@ -37,6 +37,16 @@ _mnt_fs() {
echo $(readlink -f /dev/mapper/${dm_snap_name}) >> /run/archiso/used_block_devices echo $(readlink -f /dev/mapper/${dm_snap_name}) >> /run/archiso/used_block_devices
} }
# args: source, newroot, mountpoint
_mnt_overlayfs() {
local src="${1}"
local newroot="${2}"
local mnt="${3}"
mkdir -p /run/archiso/cowspace/${cow_directory}/upperdir /run/archiso/cowspace/${cow_directory}/workdir
mount -t overlay -o lowerdir=${src},upperdir=/run/archiso/cowspace/${cow_directory}/upperdir,workdir=/run/archiso/cowspace/${cow_directory}/workdir airootfs "${newroot}${mnt}"
}
# args: /path/to/image_file, mountpoint # args: /path/to/image_file, mountpoint
_mnt_sfs() { _mnt_sfs() {
local img="${1}" local img="${1}"
@ -165,7 +175,11 @@ archiso_mount_handler() {
mkdir -p "/run/archiso/cowspace/${cow_directory}" mkdir -p "/run/archiso/cowspace/${cow_directory}"
_mnt_sfs "/run/archiso/bootmnt/${archisobasedir}/${arch}/airootfs.sfs" "/run/archiso/sfs/airootfs" _mnt_sfs "/run/archiso/bootmnt/${archisobasedir}/${arch}/airootfs.sfs" "/run/archiso/sfs/airootfs"
_mnt_fs "/run/archiso/sfs/airootfs/airootfs.img" "${newroot}" "/" if [[ -f "/run/archiso/sfs/airootfs/airootfs.img" ]]; then
_mnt_dmsnapshot "/run/archiso/sfs/airootfs/airootfs.img" "${newroot}" "/"
else
_mnt_overlayfs "/run/archiso/sfs/airootfs" "${newroot}" "/"
fi
if [[ "${copytoram}" == "y" ]]; then if [[ "${copytoram}" == "y" ]]; then
umount /run/archiso/bootmnt umount /run/archiso/bootmnt

View File

@ -4,6 +4,7 @@ build() {
add_module "cdrom" add_module "cdrom"
add_module "loop" add_module "loop"
add_module "dm-snapshot" add_module "dm-snapshot"
add_module "overlay"
add_runscript add_runscript

View File

@ -16,6 +16,7 @@ iso_application="Arch Linux Live/Rescue CD"
install_dir="arch" install_dir="arch"
work_dir="work" work_dir="work"
out_dir="out" out_dir="out"
sfs_mode="img"
sfs_comp="xz" sfs_comp="xz"
# Show an INFO message # Show an INFO message
@ -87,6 +88,10 @@ _usage ()
echo " Default: '${work_dir}'" echo " Default: '${work_dir}'"
echo " -o <out_dir> Set the output directory" echo " -o <out_dir> Set the output directory"
echo " Default: '${out_dir}'" echo " Default: '${out_dir}'"
echo " -s <sfs_mode> Set SquashFS image mode (img or sfs)"
echo " img: prepare airootfs.sfs for dm-snapshot usage"
echo " sfs: prepare airootfs.sfs for overlayfs usage"
echo " Default: ${sfs_mode}"
echo " -c <comp_type> Set SquashFS compression type (gzip, lzma, lzo, xz)" echo " -c <comp_type> Set SquashFS compression type (gzip, lzma, lzo, xz)"
echo " Default: '${sfs_comp}'" echo " Default: '${sfs_comp}'"
echo " -v Enable verbose output" echo " -v Enable verbose output"
@ -193,8 +198,8 @@ _cleanup () {
_msg_info "Done!" _msg_info "Done!"
} }
# Makes a filesystem from a source directory. # Makes a ext4 filesystem inside a SquashFS from a source directory.
_mkairootfs () { _mkairootfs_img () {
if [[ ! -e "${work_dir}/airootfs" ]]; then if [[ ! -e "${work_dir}/airootfs" ]]; then
_msg_error "The path '${work_dir}/airootfs' does not exist" 1 _msg_error "The path '${work_dir}/airootfs' does not exist" 1
fi fi
@ -224,6 +229,22 @@ _mkairootfs () {
rm ${work_dir}/airootfs.img rm ${work_dir}/airootfs.img
} }
# Makes a SquashFS filesystem from a source directory.
_mkairootfs_sfs () {
if [[ ! -e "${work_dir}/airootfs" ]]; then
_msg_error "The path '${work_dir}/airootfs' does not exist" 1
fi
mkdir -p "${work_dir}/iso/${install_dir}/${arch}"
_msg_info "Creating SquashFS image, this may take some time..."
if [[ "${quiet}" = "y" ]]; then
mksquashfs "${work_dir}/airootfs" "${work_dir}/iso/${install_dir}/${arch}/airootfs.sfs" -noappend -comp "${sfs_comp}" -no-progress &> /dev/null
else
mksquashfs "${work_dir}/airootfs" "${work_dir}/iso/${install_dir}/${arch}/airootfs.sfs" -noappend -comp "${sfs_comp}" -no-progress
fi
_msg_info "Done!"
}
_mkchecksum () { _mkchecksum () {
_msg_info "Creating checksum file for self-test..." _msg_info "Creating checksum file for self-test..."
cd "${work_dir}/iso/${install_dir}/${arch}" cd "${work_dir}/iso/${install_dir}/${arch}"
@ -292,7 +313,11 @@ command_prepare () {
_show_config prepare _show_config prepare
_cleanup _cleanup
_mkairootfs if [[ ${sfs_mode} == "sfs" ]]; then
_mkairootfs_sfs
else
_mkairootfs_img
fi
_mkchecksum _mkchecksum
} }
@ -330,7 +355,7 @@ if [[ ${EUID} -ne 0 ]]; then
_msg_error "This script must be run as root." 1 _msg_error "This script must be run as root." 1
fi fi
while getopts 'p:r:C:L:P:A:D:w:o:c:vh' arg; do while getopts 'p:r:C:L:P:A:D:w:o:s:c:vh' arg; do
case "${arg}" in case "${arg}" in
p) pkg_list="${pkg_list} ${OPTARG}" ;; p) pkg_list="${pkg_list} ${OPTARG}" ;;
r) run_cmd="${OPTARG}" ;; r) run_cmd="${OPTARG}" ;;
@ -341,6 +366,7 @@ while getopts 'p:r:C:L:P:A:D:w:o:c:vh' arg; do
D) install_dir="${OPTARG}" ;; D) install_dir="${OPTARG}" ;;
w) work_dir="${OPTARG}" ;; w) work_dir="${OPTARG}" ;;
o) out_dir="${OPTARG}" ;; o) out_dir="${OPTARG}" ;;
s) sfs_mode="${OPTARG}" ;;
c) sfs_comp="${OPTARG}" ;; c) sfs_comp="${OPTARG}" ;;
v) quiet="n" ;; v) quiet="n" ;;
h|?) _usage 0 ;; h|?) _usage 0 ;;