X-Git-Url: http://git.grml.org/?a=blobdiff_plain;f=scripts%2Flive-helpers;h=889d1576af313853f2ffb04f220ab8cb79d55425;hb=e5167694c7c6212ac8eb03cd7b2231ba4f68c3e0;hp=7eb45e930071f1c7e904bcf041c2028a1dd34262;hpb=0804cf7a59f902703340ce47b4e0c93f93cc20e9;p=live-boot-grml.git

diff --git a/scripts/live-helpers b/scripts/live-helpers
index 7eb45e9..889d157 100644
--- a/scripts/live-helpers
+++ b/scripts/live-helpers
@@ -519,8 +519,9 @@ where_is_mounted ()
 }
 
 trim_path () {
-    # remove all unnecessary /:s in the path, including last
-    echo ${1} | sed 's|//|/|g' | sed 's|/$||'
+    # remove all unnecessary /:s in the path, including last one (except
+    # if path is just "/")
+    echo ${1} | sed 's|//\+|/|g' | sed 's|^\(.*[^/]\)/$|\1|'
 }
 
 what_is_mounted_on ()
@@ -529,6 +530,24 @@ what_is_mounted_on ()
 	grep -m1 "^[^ ]\+ ${dir} " /proc/mounts | cut -d' ' -f1
 }
 
+chown_ref ()
+{
+	local reference="${1}"
+	shift
+	local targets=${@}
+	local owner=$(stat -c %u:%g "${reference}")
+	chown -h ${owner} ${targets}
+}
+
+chmod_ref ()
+{
+	local reference="${1}"
+	shift
+	local targets=${@}
+	local rights=$(stat -c %a "${reference}")
+	chmod ${rights} ${targets}
+}
+
 lastline ()
 {
 	while read lines
@@ -1139,8 +1158,8 @@ link_files ()
 	# live-boot normally does (into $rootmnt)).
 
 	# remove multiple /:s and ensure ending on /
-	local src_dir="$(echo "${1}"/ | sed -e 's|/\+|/|g')"
-	local dest_dir="$(echo "${2}"/ | sed -e 's|/\+|/|g')"
+	local src_dir="$(trim_path ${1})/"
+	local dest_dir="$(trim_path ${2})/"
 	local src_mask="${3}"
 
 	# This check can only trigger on the inital, non-recursive call since
@@ -1162,18 +1181,19 @@ link_files ()
 			if [ ! -d "${dest}" ]
 			then
 				mkdir -p "${dest}"
-				prev="$(dirname "${dest}")"
-				chown --reference "${prev}" "${dest}"
-				chmod --reference "${prev}" "${dest}"
+				chown_ref "${src}" "${dest}"
+				chmod_ref "${src}" "${dest}"
 			fi
 			link_files "${src}" "${dest}" "${src_mask}"
 		else
+			local final_src=${src}
 			if [ -n "${src_mask}" ]
 			then
-				src="$(echo ${src} | sed "s|^${src_mask}||")"
+				final_src="$(echo ${final_src} | sed "s|^${src_mask}||")"
 			fi
 			rm -rf "${dest}" 2> /dev/null
-			ln -s "${src}" "${dest}"
+			ln -s "${final_src}" "${dest}"
+			chown_ref "${src}" "${dest}"
 		fi
 	done
 }
@@ -1277,35 +1297,32 @@ get_custom_mounts ()
 			cp ${include_list} ${rootmnt}/live/persistent/${persistence_list}.${device_name}
 		fi
 
-		while read source dest options # < ${include_list}
+		while read dir options # < ${include_list}
 		do
-			if echo ${source} | grep -qe "^[[:space:]]*\(#.*\)\?$"
+			if echo ${dir} | grep -qe "^[[:space:]]*\(#.*\)\?$"
 			then
 				# skipping empty or commented lines
 				continue
 			fi
 
-			if [ -z "${dest}" ]
+			if trim_path ${dir} | grep -q -e "^[^/]" -e "^/$" -e "^/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
 			then
-				dest="${source}"
-			fi
-
-			if trim_path ${source} | grep -q -e "^[^/]" -e "^\(.*/\)\?\.\.\?\(/.*\)\?$"
-			then
-				log_warning_msg "Skipping unsafe custom mount with source ${source}: the source must be an absolute path w.r.t. the persistent media root and cannot contain \".\" or \"..\""
-				continue
-			fi
-
-			if trim_path ${dest} | grep -q -e "^[^/]" -e "^/$" -e "^/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
-			then
-				log_warning_msg "Skipping unsafe custom mount with desination ${dest}: the destination must be an absolute path containing neither \".\" nor \"..\", and cannot be /live (or any sub-directory therein) or / (for the latter, use ${root_overlay_label}-type persistence instead)"
+				log_warning_msg "Skipping unsafe custom mount ${dir}: must be an absolute path containing neither the \".\" nor \"..\" special dirs, and cannot be \"/live\" (or any sub-directory therein) or \"/\" (for the latter, use ${root_overlay_label}-type persistence)"
 				continue
 			fi
 
+			local opt_source=""
+			local opt_linkfiles=""
 			for opt in $(echo ${options} | tr ',' ' ');
 			do
 				case "${opt}" in
-					linkfiles|union)
+					source=*)
+						opt_source=${opt#source=}
+						;;
+					linkfiles)
+						opt_linkfiles="yes"
+						;;
+					union|bind)
 						;;
 					*)
 						log_warning_msg "Skipping custom mount with unkown option: ${opt}"
@@ -1314,10 +1331,21 @@ get_custom_mounts ()
 				esac
 			done
 
-			# ensure that no multiple-/ occur in paths
+			local source="${dir}"
+			if [ -n "${opt_source}" ]
+			then
+				if echo ${opt_source} | grep -q -e "^/" -e "^\(.*/\)\?\.\.\?\(/.*\)\?$" && [ "${source}" != "." ]
+				then
+					log_warning_msg "Skipping unsafe custom mount with option source=${opt_source}: must be either \".\" (the media root) or a relative path w.r.t. the media root that contains neither comas, nor the special \".\" and \"..\" path components"
+					continue
+				else
+					source="${opt_source}"
+				fi
+			fi
+
 			local full_source="$(trim_path ${backing}/${source})"
-			local full_dest="$(trim_path ${rootmnt}/${dest})"
-			if echo ${options} | grep -qe "\<linkfiles\>";
+			local full_dest="$(trim_path ${rootmnt}/${dir})"
+			if [ -n "${opt_linkfiles}" ]
 			then
 				echo "${device} ${full_source} ${full_dest} ${options}" >> ${links}
 			else
@@ -1333,7 +1361,24 @@ get_custom_mounts ()
 
 	# After all mounts are considered we add symlinks so they
 	# won't be hidden by some mount.
-	[ -e "${links}" ] && sort -k3 -sbu ${links} >> ${custom_mounts} && rm ${links}
+	[ -e "${links}" ] && cat ${links} >> ${custom_mounts} && rm ${links}
+
+	# We need to make sure that no two custom mounts have the same sources
+	# or are nested; if that is the case, too much weird stuff can happen.
+	local prev_source="impossible source" # first iteration must not match
+	local prev_dest=""
+	# This sort will ensure that a source /a comes right before a source
+	# /a/b so we only need to look at the previous source
+	sort -k2 -b ${custom_mounts} |
+	while read device source dest options
+	do
+		if echo ${source} | grep -qe "^${prev_source}\(/.*\)\?$"
+		then
+			panic "Two persistent mounts have the same or nested sources: ${source} on ${dest}, and ${prev_source} on ${prev_dest}"
+		fi
+		prev_source=${source}
+		prev_dest=${dest}
+	done
 }
 
 activate_custom_mounts ()
@@ -1343,53 +1388,56 @@ activate_custom_mounts ()
 
 	while read device source dest options # < ${custom_mounts}
 	do
+		local opt_bind="yes"
 		local opt_linkfiles=""
 		local opt_union=""
 		for opt in $(echo ${options} | tr ',' ' ');
 		do
-			 case "${opt}" in
+			case "${opt}" in
+				bind)
+					opt_bind="yes"
+					unset opt_linkfiles opt_union
+					;;
 				linkfiles)
 					opt_linkfiles="yes"
+					unset opt_bind opt_union
 					;;
 				union)
 					opt_union="yes"
+					unset opt_bind opt_linkfiles
 					;;
 			esac
 		done
 
 		if [ -n "$(what_is_mounted_on "${dest}")" ]
 		then
-			log_warning_msg "Skipping custom mount ${source} on ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
+			log_warning_msg "Skipping custom mount ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
 			continue
 		fi
 
-		# FIXME: we don't handle already existing
-		# non-directory files in the paths of both $source and
-		# $dest.
-
 		if [ ! -d "${dest}" ]
 		then
-			# if ${dest} is in /home/$user, try fixing
-			# proper ownership
-			# FIXME: this should really be handled by
-			# live-config since we don't know for sure
-			# which uid a certain user has until then
-			if trim_path ${dest} | grep -qe "^${rootmnt}/*home/[^/]\+"
-			then
-				path="/"
-				for dir in $(echo ${dest} | sed -e 's|/\+| |g')
-				do
-					path=${path}/${dir}
-					if [ ! -e ${path} ]
+			# create the destination and delete existing files in
+			# its path that are in the way
+			path="/"
+			for dir in $(echo ${dest} | sed -e 's|/\+| |g')
+			do
+				path=$(trim_path ${path}/${dir})
+				if [ -f ${path} ]
+				then
+					rm -f ${path}
+				fi
+				if [ ! -e ${path} ]
+				then
+					mkdir -p ${path}
+					if echo ${path} | grep -qe "^${rootmnt}/*home/[^/]\+"
 					then
-						mkdir -p ${path}
-						# assume that the intended user is the first, which is usually the case
+						# if ${dest} is in /home try fixing proper ownership by assuming that the intended user is the first, which is usually the case
+						# FIXME: this should really be handled by live-config since we don't know for sure which uid a certain user has until then
 						chown 1000:1000 ${path}
 					fi
-				done
-			else
-				mkdir -p ${dest}
-			fi
+				fi
+			done
 		fi
 
 		# if ${source} doesn't exist on our persistent media
@@ -1405,69 +1453,98 @@ activate_custom_mounts ()
 			then
 				# unions and don't need to be bootstrapped
 				# linkfiles dirs can't be bootstrapped in a sensible way
-				mkdir "${source}"
-				chown --reference "${dest}" "${source}"
-				chmod --reference "${dest}" "${source}"
-			else
+				mkdir -p "${source}"
+				chown_ref "${dest}" "${source}"
+				chmod_ref "${dest}" "${source}"
+			elif [ -n "${opt_bind}" ]
+			then
 				# ensure that $dest is not copied *into* $source
 				mkdir -p "$(dirname ${source})"
 				cp -a "${dest}" "${source}"
 			fi
 		fi
 
-		rofs_dest_backing=""
-		for d in ${rootmnt}/live/rofs/*
-		do
+		# XXX: If CONFIG_AUFS_ROBR is added to the Debian kernel we can
+		# ignore the loop below and set rofs_dest_backing=$dest
+		local rofs_dest_backing=""
+		if [ -n "${opt_linkfiles}"]
+		then
+			for d in ${rootmnt}/live/rofs/*
+			do
+				if [ -n "${rootmnt}" ]
+				then
+					rofs_dest_backing="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
+				else
+					rofs_dest_backing="${d}/${dest}"
+				fi
+				if [ -d "${rofs_dest_backing}" ]
+				then
+					break
+				else
+					rofs_dest_backing=""
+				fi
+			done
+		fi
+
+		if [ -n "${opt_linkfiles}" ] && [ -z "${PERSISTENT_READONLY}" ]
+		then
+			link_files ${source} ${dest} ${rootmnt}
+		elif [ -n "${opt_linkfiles}" ] && [ -n "${PERSISTENT_READONLY}" ]
+		then
+			mkdir -p ${rootmnt}/live/persistent
+			local links_source=$(mktemp -d ${rootmnt}/live/persistent/links-source-XXXXXX)
+			chown_ref ${source} ${links_source}
+			chmod_ref ${source} ${links_source}
+			# We put the cow dir in the below strange place to
+			# make it absolutely certain that the link source
+			# has its own directory and isn't nested with some
+			# other custom mount (if so that mount's files would
+			# be linked, causing breakage.
 			if [ -n "${rootmnt}" ]
 			then
-				rofs_dest_backing="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
+				local cow_dir="/cow/live/persistent/$(basename ${links_source})"
 			else
-				rofs_dest_backing="${d}/${dest}"
+				# This is happens if persistence is activated
+				# post boot
+				local cow_dir="/live/cow/live/persistent/$(basename ${links_source})"
 			fi
-			if [ -d "${rofs_dest_backing}" ]
-			then
-				break
-			else
-				rofs_dest_backing=""
-			fi
-		done
-
-		if [ -z "${PERSISTENT_READONLY}" ]
+			mkdir -p ${cow_dir}
+			chown_ref "${source}" "${cow_dir}"
+			chmod_ref "${source}" "${cow_dir}"
+			do_union ${links_source} ${cow_dir} ${source} ${rofs_dest_backing}
+			link_files ${links_source} ${dest} ${rootmnt}
+		elif [ -n "${opt_union}" ] && [ -z "${PERSISTENT_READONLY}" ]
 		then
-			if [ -n "${opt_linkfiles}" ]
-			then
-				links_source="${source}"
-				links_dest="${dest}"
-			elif [ -n "${opt_union}" ]
+			do_union ${dest} ${source} ${rofs_dest_backing}
+		elif [ -n "${opt_bind}" ] && [ -z "${PERSISTENT_READONLY}" ]
+		then
+			mount --bind "${source}" "${dest}"
+		elif [ -n "${opt_bind}" -o -n "${opt_union}" ] && [ -n "${PERSISTENT_READONLY}" ]
+		then
+			# bind-mount and union mount are handled the same
+			# in read-only mode, but note that rofs_dest_backing
+			# is non-empty (and necessary) only for unions
+			if [ -n "${rootmnt}" ]
 			then
-				do_union ${dest} ${source} ${rofs_dest_backing}
+				local cow_dir="$(echo ${dest} | sed -e "s|^${rootmnt}|/cow/|")"
 			else
-				mount --bind "${source}" "${dest}"
+				# This is happens if persistence is activated
+				# post boot
+				local cow_dir="/live/cow/${dest}"
 			fi
-		else
-			if [ -n "${opt_linkfiles}" ]
+			if [ -e "${cow_dir}" ] && [ -z "${opt_linkfiles}" ]
 			then
-				links_dest="${dest}"
-				dest="$(mktemp -d ${persistent_backing}/links_source-XXXXXX)"
-				links_source="${dest}"
-			fi
-			if [ -n "${rootmnt}" ]
-			then
-				cow_dir="$(echo ${dest} | sed -e "s|${rootmnt}|/cow/|")"
-			else
-				cow_dir="/live/cow/${dest}"
+				# If an earlier custom mount has files here
+				# it will "block" the current mount's files
+				# which is undesirable
+				rm -rf "${cow_dir}"
 			fi
 			mkdir -p ${cow_dir}
-			chown --reference "${source}" "${cow_dir}"
-			chmod --reference "${source}" "${cow_dir}"
+			chown_ref "${source}" "${cow_dir}"
+			chmod_ref "${source}" "${cow_dir}"
 			do_union ${dest} ${cow_dir} ${source} ${rofs_dest_backing}
 		fi
 
-		if [ -n "${opt_linkfiles}" ]
-		then
-			link_files "${links_source}" "${links_dest}" "${rootmnt}"
-		fi
-
 		PERSISTENCE_IS_ON="1"
 		export PERSISTENCE_IS_ON
 
@@ -1499,6 +1576,6 @@ fix_home_rw_compatibility ()
 	if [ ! -r "${include_list}" ]
 	then
 		echo "# home-rw backwards compatibility:
-/ /home" > "${include_list}"
+/home source=." > "${include_list}"
 	fi
 }