#!/bin/sh
# 9013-toram-retry.hook.chroot — wrap live-boot's "copy whole medium to RAM"
# rsync in a retry loop with exponential backoff.
#
# Why: on some hosts the boot medium (notably BMC / IPMI virtual CD redirection)
# drops off the bus part-way through the ~2.8 GB squashfs read.  rsync then dies
# with "Input/output error (5)" and every file "has vanished", live-boot moves
# the partial RAM copy over the medium, and the boot ends with
# "No supported filesystem images found at /live" -> BOOT FAILED.
#
# live-boot's own retry is just rsync's single in-run delta retry.  This patch
# adds several full attempts with a geometrically growing pause between them
# (15s, 30s, 60s, 120s, 240s, 480s, 900s), giving the virtual media time to
# re-enumerate.  Between attempts the medium is unmounted, waited on, and
# remounted.  rsync resumes (already-copied files are skipped), so a retry that
# only needs the tail of the squashfs finishes quickly.
set -e

TORAM_SCRIPT="/usr/lib/live/boot/9990-toram-todisk.sh"

if [ ! -f "${TORAM_SCRIPT}" ]; then
    echo "9013-toram-retry: ${TORAM_SCRIPT} not found, skipping"
    exit 0
fi

if grep -q "bee_rsync_retry" "${TORAM_SCRIPT}"; then
    echo "9013-toram-retry: already patched, skipping"
    exit 0
fi

RSYNC_LINE='rsync -a --progress ${copyfrom}/\* ${copyto} 1>/dev/console'
if ! grep -qF 'rsync -a --progress ${copyfrom}/* ${copyto} 1>/dev/console' "${TORAM_SCRIPT}"; then
    echo "9013-toram-retry: expected rsync line not found in ${TORAM_SCRIPT}" >&2
    echo "9013-toram-retry: live-boot layout changed -- refusing to patch blindly" >&2
    exit 1
fi

echo "9013-toram-retry: patching ${TORAM_SCRIPT}"

# 1. Inject the retry helper right after the shebang.
cat > /tmp/bee_rsync_retry.func <<'FUNC'

# --- bee: retry the whole-medium RAM copy with exponential backoff ----------
bee_rsync_retry ()
{
	_src="${1}"
	_dst="${2}"
	_dev=$(awk -v m="${_src}" '$2 == m {print $1; exit}' /proc/mounts)
	_fst=$(awk -v m="${_src}" '$2 == m {print $3; exit}' /proc/mounts)
	_delay=15
	_maxdelay=900
	_try=1
	_maxtry=8

	while : ; do
		echo " * bee: toram copy attempt ${_try}/${_maxtry} (medium ${_dev:-?} ${_fst:-?})" 1>/dev/console

		if rsync -a --progress --timeout=180 ${_src}/* ${_dst} 1>/dev/console
		then
			echo " * bee: toram copy completed on attempt ${_try}" 1>/dev/console
			return 0
		fi

		echo " * bee: toram copy FAILED (rsync rc=$?) on attempt ${_try}" 1>/dev/console

		if [ "${_try}" -ge "${_maxtry}" ]
		then
			echo " * bee: giving up after ${_try} attempts" 1>/dev/console
			return 1
		fi

		echo " * bee: waiting ${_delay}s for the medium to re-settle..." 1>/dev/console
		sleep "${_delay}"

		# Recover the medium: unmount, wait for the device node, remount.
		if [ -n "${_dev}" ]
		then
			umount "${_src}" 2>/dev/null || umount -l "${_src}" 2>/dev/null || true
			_w=0
			while [ ! -b "${_dev}" ] && [ "${_w}" -lt 120 ]
			do
				sleep 3
				_w=$((_w + 3))
			done
			mount -r ${_fst:+-t ${_fst}} "${_dev}" "${_src}" 2>/dev/null \
				|| mount -r "${_dev}" "${_src}" 2>/dev/null \
				|| echo " * bee: remount of ${_dev} failed, will retry anyway" 1>/dev/console
		fi

		_try=$((_try + 1))
		_delay=$((_delay * 2))
		[ "${_delay}" -gt "${_maxdelay}" ] && _delay="${_maxdelay}"
	done
}
FUNC

sed -i "2r /tmp/bee_rsync_retry.func" "${TORAM_SCRIPT}"
rm -f /tmp/bee_rsync_retry.func

# 2. Route the whole-medium copy through the helper and honour its exit code
#    (upstream ignores rsync's exit status and moves the partial copy anyway).
sed -i \
  's#\([[:space:]]*\)rsync -a --progress ${copyfrom}/[*] ${copyto} 1>/dev/console.*#\1bee_rsync_retry "${copyfrom}" "${copyto}" || { log_warning_msg "bee: toram copy failed after all retries"; rmdir "${copyto}" 2>/dev/null || true; return 1; }#' \
  "${TORAM_SCRIPT}"

if ! grep -q "bee_rsync_retry \"\${copyfrom}\"" "${TORAM_SCRIPT}"; then
    echo "9013-toram-retry: call-site substitution failed" >&2
    exit 1
fi

echo "9013-toram-retry: patch applied"
grep -n "bee_rsync_retry" "${TORAM_SCRIPT}"

# 3. Rebuild the initramfs so the patched script lands in initrd.img.
KVER=$(ls /lib/modules | sort -V | tail -1)
echo "9013-toram-retry: rebuilding initramfs for kernel ${KVER}"
update-initramfs -u -k "${KVER}"
echo "9013-toram-retry: done"