scripts/local: Apply a single time limit to all device discovery

Instead of counting how many times we wait and poll for each critical
device (root or /usr) to appear, use /proc/uptime to tell how long we
have waited in total (starting from when local_top runs).

This is complicated by the hack mdadm's local-block uses to decide
when 2/3 of the time limit has expired.  Use an even worse hack to
keep it working.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

1 files changed, 36 insertions, 2 deletions

diff --git a/scripts/local b/scripts/local
index a4ddcea..3707440 100644
--- a/scripts/local
+++ b/scripts/local
@@ -8,6 +8,14 @@ local_top()
 		[ "$quiet" != "y" ] && log_end_msg
 	fi
 	local_top_used=yes
+
+	# Start time for measuring elapsed time in local_device_setup
+	if [ -z "${local_top_time}" ]; then
+		local_top_time="$(cat /proc/uptime)"
+		local_top_time="${local_top_time%%[. ]*}"
+		local_top_time=$((local_top_time + 1)) # round up
+		export local_top_time
+	fi
 }
 
 local_block()
@@ -36,6 +44,7 @@ local_bottom()
 	fi
 	local_premount_used=no
 	local_top_used=no
+	unset local_top_time
 }
 
 # $1=device ID to mount
@@ -46,6 +55,8 @@ local_device_setup()
 	local dev_id="$1"
 	local name="$2"
 	local real_dev
+	local time_elapsed
+	local count
 
 	wait_for_udev 10
 
@@ -81,15 +92,38 @@ local_device_setup()
 
 		while true; do
 			sleep 1
+			time_elapsed="$(cat /proc/uptime)"
+			time_elapsed="${time_elapsed%%[. ]*}"
+			time_elapsed=$((time_elapsed - local_top_time))
+
 			local_block "${dev_id}"
+
+			# If mdadm's local-block script counts the
+			# number of times it is run, make sure to
+			# run it the expected number of times.
+			while true; do
+				if [ -f /run/count.mdadm.initrd ]; then
+					count="$(cat /run/count.mdadm.initrd)"
+				elif [ -n "${count}" ]; then
+					# mdadm script deleted it; put it back
+					count=$((count + 1))
+					echo "${count}" >/run/count.mdadm.initrd
+				else
+					break
+				fi
+				if [ ${count} -ge ${time_elapsed} ]; then
+					break;
+				fi
+				/scripts/local-block/mdadm "${dev_id}"
+			done
+
 			if real_dev=$(resolve_device "${dev_id}") &&
 			   get_fstype "${real_dev}" >/dev/null; then
 				wait_for_udev 10
 				log_end_msg 0
 				break
 			fi
-			slumber=$(( ${slumber} - 1 ))
-			if [ ${slumber} -eq 0 ]; then
+			if [ ${time_elapsed} -ge ${slumber} ]; then
 				log_end_msg 1 || true
 				break
 			fi