minimal-init: Try to load modules for all devices again after a timeout (#114)

Normally it works to do one full module load and then the drive is
detected but in case this takes longer and mdev doesn't do the job of
module loading we can fall back to a full load again to try to progress.
So far we don't know if this helps (it won't for completly missing
kernel modules of course) but it's good to have this done automatically
instead of having to ask users if it helps for them when they hit an
issue.

## How to use


## Testing done

With a wrong verity usr kernel cmdline arg it now prints "Still waiting"
every five seconds.

Author: pothos

minimal-init

@@ -44,11 +44,15 @@ if [ "$(cmdline_arg rd.earlytrace)" != "" ]; then
   set -x
 fi
 
+loadmodules() {
+  # Coldplugging but with using /sbin/modprobe (which is kmod) instead of busybox's modprobe
+  # because busybox doesn't properly support the globs in modules.alias
+  find /sys/ -name modalias -print0 | xargs -0 sort -u | tr '\n' '\0' | xargs -0 /sbin/modprobe -abq || true
+}
+
 mdev -d
 mdev -s
-# Coldplugging but with using /sbin/modprobe (which is kmod) instead of busybox's modprobe
-# because busybox doesn't properly support the globs in modules.alias
-find /sys/ -name modalias -print0 | xargs -0 sort -u | tr '\n' '\0' | xargs -0 /sbin/modprobe -abq || true
+loadmodules
 # Required to access disks, but not autoloaded:
 /sbin/modprobe sd_mod
 
@@ -100,7 +104,13 @@ find_drive() {
       echo "ERROR: Timeout waiting for drive: ${ueventline}${blkidmatch}" >&2
       return 1 # Throw error
     fi
-    # No "sleep 0.1", so this is rather busy polling
+    if [ $((now - starttime)) -gt 10 ]; then
+      sleep 5
+      echo "Still waiting for drive..." >&2
+      loadmodules
+    fi
+    # No "sleep 0.1", so this is rather busy polling but normally it works on first try
+    # and after some time we stop busy polling and have the longer sleep above
     if [ "${ueventline}" != "" ]; then
       drive="$({ grep -s -l -m 1 -r "${ueventline}" /sys/class/block/*/uevent || true; } | cut -d / -f 5)"
     else