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VyOS mount process while booting
initrd内init: scripts/liveをkickする存在
maybe_break mount
log_begin_msg "Mounting root file system"
. /scripts/${BOOT}
parse_numeric ${ROOT}
maybe_break mountroot
mountroot
log_end_msg
→${BOOT}は/proc/cmdline(kernelパラメータ)のboot=の値。grub.cfgは以下なのでboot=live.
menuentry "VyOS 1.1.0 linux (KVM console)" {
linux /boot/1.1.0/vmlinuz boot=live quiet vyatta-union=/boot/1.1.0 console=ttyS0,9600 console=tty0
initrd /boot/1.1.0/initrd.img
}
/etc/mtab
$ cat /etc/mtab
overlayfs / overlayfs rw 0 0
tmpfs /lib/init/rw tmpfs rw,nosuid,mode=0755 0 0
proc /proc proc rw,noexec,nosuid,nodev 0 0
sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0
udev /dev tmpfs rw,mode=0755 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=620 0 0
/dev/sda1 /live/image ext4 rw,relatime,data=ordered 0 0
/dev/sda1 /live/cow ext4 rw,relatime,data=ordered 0 0
tmpfs /live tmpfs rw,relatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,relatime 0 0
/dev/sda1 /opt/vyatta/etc/config ext4 rw,relatime,data=ordered 0 0
tmpfs /var/run tmpfs rw,nosuid,nodev 0 0
fusectl /sys/fs/fuse/connections fusectl rw 0 0
none /opt/vyatta/config tmpfs rw,nosuid,nodev,mode=775,nr_inodes=0 0 0
/live/image/boot/1.1.0 /boot none rw,bind 0 0
/live/image/boot/grub /boot/grub none rw,bind 0 0
$ cat /proc/mounts
rootfs / rootfs rw,size=246316k,nr_inodes=61579 0 0
none /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
none /proc proc rw,nosuid,nodev,noexec,relatime 0 0
none /dev devtmpfs rw,relatime,size=246324k,nr_inodes=61581,mode=755 0 0
none /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620 0 0
/dev/sda1 /live/image ext4 rw,relatime,data=ordered 0 0
/dev/loop0 /1.1.0.squashfs squashfs ro,noatime 0 0
/dev/sda1 /live-rw-backing ext4 rw,relatime,data=ordered 0 0
/dev/sda1 /live/cow ext4 rw,relatime,data=ordered 0 0
overlayfs / overlayfs rw,relatime,lowerdir=//1.1.0.squashfs,upperdir=/cow 0 0
tmpfs /live tmpfs rw,relatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,relatime 0 0
/dev/sda1 /opt/vyatta/etc/config ext4 rw,relatime,data=ordered 0 0
tmpfs /lib/init/rw tmpfs rw,nosuid,relatime,mode=755 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev,relatime 0 0
tmpfs /var/run tmpfs rw,nosuid,nodev,relatime 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
none /opt/vyatta/config tmpfs rw,nosuid,nodev,relatime,nr_inodes=0,mode=775 0 0
/dev/sda1 /boot ext4 rw,relatime,data=ordered 0 0
/dev/sda1 /boot/grub ext4 rw,relatime,data=ordered 0 0
===> は、対応する/proc/mountsの行
https://github.com/vyos/initramfs-tools/blob/573e21e410934f2293d5ac4c738af5f77083b43b/init
mountroot #init:L218
https://github.com/vyos/live-initramfs/blob/47cb65a9b94ca48696e8e0255c921167ddcfb49b/scripts/live
mountroot #L1605
-> livefs_root=$(find_livefs ${i})
# $i: 0...60 (timeoutカウンタ)
-> check_dev "${dev}" # L1546
# $dev: "/dev/sda1" #L1531,L1533,L1544の結果からおそらく
-> mount -t ${fstype} -o ro,noatime "${devname}" ${mountpoint} #L1449
# $fstype: "ext4" #L1445のget_fstypeの結果からおそらく
# $devname: "/dev/sda1" #L1423の結果からおそらく
# $mountpoint: "/live/image" #L10
===> mount -t ext4 -o ro,noatime /dev/sda1 /live/image (後の/dev/sda1 /live/image ext4 rw,relatime,data=ordered 0 0)
# livefs_rootには/live/imageが入る
-> mount_images_in_directory "${livefs_root}" "${rootmnt}" "${mac}" # L1700
-> setup_unionfs "${directory}/${LIVE_MEDIA_PATH}" "${rootmnt}" "${adddirectory}" # L609
# $directory: $livefs_root
# $LIVE_MEDIA_PATH: "live" #L11
-> mount -t "${fstype}" -o ro,noatime "${backdev}" "${croot}/${imagename}" # L1178
# $backdev: backdev=$(get_backing_device "${image}" "-r") #L1161
# $(setup_loop "${1}" "loop" "/sys/block/loop*" '0' "${LIVE_MEDIA_ENCRYPTION}" "${2}") #L569
# $croot: "/" #L1071
# $imagename: imagename=$(basename "${image}") #L1142
===> mount -t squashfs -o ro,noatime /dev/loop0 /1.1.0.squashfs (/dev/loop0 /1.1.0.squashfs squashfs ro,noatime 0 0)
-> # cowprobe=$(find_cow_device "${root_persistence}") #L1223
# $root_persistence: "live-rw" #L13
-> find_cow_device #scripts/live-helpers:L333
-> if ! try_mount "${devname}" "${cow_backing}" "rw"
# $cow_backing: cow_backing="/${pers_label}-backing" #script/live-helpers:L339
# $pers_label: $root_persistence #script/live-helpers:L338
# つまり、$cow_backingは"/live-rw-backing"
# $devname: 探索の結果から/dev/sda1 (のはず)
-> mount -o remount,"${opts}" "${dev}" "${old_mountp}"
# $opts: "rw" #L291
# $dev: "/dev/sda" #L289
# $old_mountp: "/live/image"
===> mount -o remount,rw /dev/sda1 /live/image (後の/dev/sda1 /live/cow ext4 rw,relatime,data=ordered 0 0)
-> mount -o bind "${old_mountp}" "${mountp}" #script/live-helpers:L314
# $old_mountp: おそらく"/live/image" #L294
# $mountp: /live-rw-backing
===> mount -o bind /live/image /live-rw-backing
(/dev/sda1 /live-rw-backing ext4 rw,relatime,data=ordered 0 0)
## find_cow_deviceはecho "${pers_fpath}"を返す #script/live-helpers:L389
# $pers_fpath: ${cow_backing}/${PERSISTENT_PATH}/${pers_label} #script/live-helpers:L346
# $PERSISTENT_PATH: "$LIVE_MEDIA_PATH" #L482
# $LIVE_MEDIA_PATH: "${ARGUMENT#vyatta-union=}" #L481
# grubのvyatta-union=は/boot/1.1.0
# すなわち、$pers_fpathは"/live-rw-backing/boot/1.1.0/live-rw"
# find_cow_deviceは${cow_backing}/${PERSISTENT_PATH}/${pers_label}である
# "/live-rw-backing/boot/1.1.0/live-rw" を返している
-> mount -o bind ${cowdevice} /cow #L1297
===> mount -o bind /live-rw-backing/boot/1.1.0/live-rw /cow (後の/dev/sda1 /live/cow ext4 rw,relatime,data=ordered 0 0)
# $cowdevice: ${cowprobe} #L1249
-> mount -t ${UNIONTYPE} -o noatime,lowerdir=${rofsstring},upperdir=/cow overlayfs "${rootmnt}" #L1345
# $UNIONTYPE: "overlayfs" #/etc/live.conf
# $rofsstring: "${croot}/${imagename}${roopt}:${rofsstring}" #L1178
# $croot: "/" #L1071
# $imagename: imagename=$(basename "${image}") #L1142
# $roopt: "" #L1087
# $rofsstring: "" #L1074
# rofsstring=${rofsstring%:} #L1183
# $rootmnt: "/root" #L62, #init:L51
==> mount -t overlayfs -o noatime,lowerdir=//1.1.0.squashfs,upperdir=/cow overlayfs /root
(overlayfs / overlayfs rw,relatime,lowerdir=//1.1.0.squashfs,upperdir=/cow 0 0)
-> mount -t tmpfs tmpfs ${rootmnt}/live #L1364
==> mount -t tmpfs tmpfs /root/live (tmpfs /live tmpfs rw,relatime 0 0)
-> mount -o move /cow "${rootmnt}/live/cow" #L1411
==> mount -o move /cow /root/live/cow (/dev/sda1 /live/cow ext4 rw,relatime,data=ordered 0 0)
run_scripts /scripts/live-bottom #L1708
-> live-bottom/05mountpoints https://github.com/vyos/live-initramfs/blob/47cb65a9b94ca48696e8e0255c921167ddcfb49b/scripts/live-bottom/05mountpoints
-> mount --move /live/image /root/live/image #scripts/live-bottom/05mountpoints:L33
===> mount --move /live/image /root/live/image (/dev/sda1 /live/image ext4 rw,relatime,data=ordered 0 0)
-> live-bottom/50vyatta
https://github.com/vyos/build-iso/blob/4ddda254c76d2bfb807ed7c2c5ea992037638bf7/livecd/config.vyatta/chroot_local-includes/usr/share/initramfs-tools/scripts/live-bottom/50vyatta
-> mount -o bind /root/live/cow/config /root/opt/vyatta/etc/config #L51
===> mount -o bind /root/live/cow/config /root/opt/vyatta/etc/config (/dev/sda1 /opt/vyatta/etc/config ext4 rw,relatime,data=ordered 0 0)
init起動
exec run-init ${rootmnt} ${init} "$@" <${rootmnt}/dev/console >${rootmnt}/dev/console #L303
check_とかprobe_とかでマウントしてそのまま使うのが気持ち悪いけど、2度マウントする無駄は避けたいか…
/etc/init.d/mountall.sh
```
tmpfs /var/run tmpfs nosuid,nodev 0 0
overlayfs / overlayfs rw 0 0
tmpfs /tmp tmpfs nosuid,nodev 0 0
```
/etc/init.d/vyatta-router
https://github.com/vyos/vyatta-cfg/blob/84c14e0983b3c2b9659af2e701b606e43306ccb2/etc/init.d/vyatta-router
-> start #L159
-> mount -o $tmpfs_opts -t tmpfs none ${vyatta_configdir} #L169
# $tmpfs_opts: nosuid,nodev,mode=775,nr_inodes=0 #L168
# $vyatta_configdir: "/opt/vyatta/config" # /etc/default/vyattaより
===> mount -o nosuid,nodev,mode=775,nr_inodes=0 -t tmpfs none /opt/vyatta/config (none /opt/vyatta/config tmpfs rw,nosuid,nodev,relatime,nr_inodes=0,mode=775 0 0)
-> mount_slashconfig #L175
-> mount --bind /opt/vyatta/etc/config /config #L154
===> /proc/mountsにはなし。このbind mountはlive環境でもそうでないときでも/configが存在するようにという配慮らしい(L139)
-> bind_mount_boot #L193 #ツール類が正しく操作できるようにという配慮(L112)
-> mount --bind /live/image/boot/$image_name /boot #L123
===> mount --bind /live/image/boot/1.1.0 /boot (/dev/sda1 /boot ext4 rw,relatime,data=ordered 0 0)
-> mount --bind /live/image/boot/grub /boot/grub #L130
===> mount --bind /live/image/boot/grub /boot/grub (/dev/sda1 /boot/grub ext4 rw,relatime,data=ordered 0 0)
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