defaults/linuxrc: Process /etc/initramfs.mounts multiple times

We need to mount mountpoints listed in /etc/initramfs.mounts
before validating REAL_INIT in case init is located on seperate
mount.

In addition the code was moved to a dedicated function named
process_initramfs_mounts() to allow to run it multiple times
which is needed if REAL_INIT wasn't verified (in case system
was booted from livecd).

Link: https://forums.gentoo.org/viewtopic-t-1117762.html
Signed-off-by: Thomas Deutschmann <whissi@gentoo.org>

2 files changed, 56 insertions, 34 deletions

diff --git a/defaults/initrd.scripts b/defaults/initrd.scripts
index 14f3c4e6..f34e5a33 100644
--- a/defaults/initrd.scripts
+++ b/defaults/initrd.scripts
@@ -1249,6 +1249,55 @@ preserve_log() {
 	fi
 }
 
+process_initramfs_mounts() {
+	local fslist=
+
+	if [ -f "${NEW_ROOT}/etc/initramfs.mounts" ]
+	then
+		fslist="$(get_mounts_list)"
+	else
+		fslist="/usr"
+	fi
+
+	local dev= fs= fstype= opts= mnt= cmd=
+	for fs in ${fslist}
+	do
+		mnt="${NEW_ROOT}${fs}"
+		if run mountpoint -q "${mnt}"
+		then
+			good_msg "${fs} already mounted, skipping..."
+			continue
+		fi
+
+		dev=$(get_mount_device "${fs}")
+		[ -z "${dev}" ] && continue
+		# Resolve it like util-linux mount does
+		[ -L "${dev}" ] && dev=$(realpath "${dev}")
+		# In this case, it's probably part of the filesystem
+		# and not a mountpoint
+		[ -z "${dev}" ] && continue
+
+		fstype=$(get_mount_fstype "${fs}")
+		if get_mount_options "${fs}" | grep -Fq bind
+		then
+			opts="bind"
+			dev="${NEW_ROOT}${dev}"
+		else
+			# ro must be trailing, and the options will always
+			# contain at least 'defaults'
+			opts="$(get_mount_options ${fs} | strip_mount_options)"
+			opts="${opts},ro"
+		fi
+
+		cmd="mount -t ${fstype} -o ${opts} ${dev} ${mnt}"
+		good_msg "Mounting ${dev} as ${fs}: ${cmd}"
+		if ! run ${cmd}
+		then
+			bad_msg "Unable to mount ${dev} for ${fs}"
+		fi
+	done
+}
+
 prompt_user() {
 	# $1 = variable whose value is the path (examples: "REAL_ROOT",
 	#      "LUKS_KEYDEV")
diff --git a/defaults/linuxrc b/defaults/linuxrc
index 3ca7e86f..e0704f7c 100644
--- a/defaults/linuxrc
+++ b/defaults/linuxrc
@@ -930,6 +930,11 @@ do
 		# else not a good root and start over.
 		if [ "${mountret}" = '0' ]
 		then
+			# Make sure that entries from $NEWROOT/etc/initramfs.mounts
+			# are mounted before validating $REAL_INIT in case init isn't
+			# located on $REAL_ROOT.
+			process_initramfs_mounts
+
 			init_binary_file="${NEW_ROOT}${REAL_INIT:-/sbin/init}"
 			init_binary_fallback_file="${NEW_ROOT}/bin/sh"
 
@@ -1261,40 +1266,8 @@ else
 	fi
 fi # if [ "${CDROOT}" = '1' ]
 
-# Mount the additional things as required by udev & systemd
-if [ -f ${NEW_ROOT}/etc/initramfs.mounts ]
-then
-	fslist=$(get_mounts_list)
-else
-	fslist="/usr"
-fi
-
-for fs in ${fslist}
-do
-	dev=$(get_mount_device ${fs})
-	[ -z "${dev}" ] && continue
-	# Resolve it like util-linux mount does
-	[ -L ${dev} ] && dev=$(readlink ${dev})
-	# In this case, it's probably part of the filesystem
-	# and not a mountpoint
-	[ -z "${dev}" ] && continue
-	fstype=$(get_mount_fstype ${fs})
-	if get_mount_options ${fs} | grep -Fq bind
-	then
-		opts='bind'
-		dev=${NEW_ROOT}${dev}
-	else
-		# ro must be trailing, and the options will always contain at least 'defaults'
-		opts="$(get_mount_options ${fs} | strip_mount_options),ro"
-	fi
-	mnt=${NEW_ROOT}${fs}
-	cmd="mount -t ${fstype} -o ${opts} ${dev} ${mnt}"
-	good_msg "Mounting ${dev} as ${fs}: ${cmd}"
-	if ! ${cmd}
-	then
-		bad_msg "Unable to mount ${dev} for ${fs}"
-	fi
-done # for fs in $fslist; do
+# Re-run to ensure $NEWROOT/etc/initramfs.mounts was processed at least once
+process_initramfs_mounts
 
 # Execute script on the cdrom just before boot to update things if necessary
 cdupdate