base/init.sh: error out early, if /dev, /proc or /sys cannot be mounted

modules.d/99base/init.sh

@@ -20,14 +20,22 @@ export PATH
 RD_DEBUG=""
 . /lib/dracut-lib.sh
 
-trap "emergency_shell Signal caught!" 0
-
 # mount some important things
 [ ! -d /proc/self ] && \
-    mount -t proc -o nosuid,noexec,nodev proc /proc >/dev/null 2>&1
+    mount -t proc -o nosuid,noexec,nodev proc /proc >/dev/null
+
+if [ "$?" != "0" ]; then
+    echo "Cannot mount proc on /proc! Compile the kernel with CONFIG_PROC_FS!"
+    exit 1
+fi
 
 [ ! -d /sys/kernel ] && \
-    mount -t sysfs -o nosuid,noexec,nodev sysfs /sys >/dev/null 2>&1
+    mount -t sysfs -o nosuid,noexec,nodev sysfs /sys >/dev/null
+
+if [ "$?" != "0" ]; then
+    echo "Cannot mount sysfs on /sys! Compile the kernel with CONFIG_SYSFS!"
+    exit 1
+fi
 
 if [ -x /lib/systemd/systemd-timestamp ]; then
     RD_TIMESTAMP=$(/lib/systemd/systemd-timestamp)
@@ -42,6 +50,11 @@ if ! ismounted /dev; then
     mount -t devtmpfs -o mode=0755,nosuid,strictatime devtmpfs /dev >/dev/null
 fi
 
+if ! ismounted /dev; then
+    echo "Cannot mount devtmpfs on /dev! Compile the kernel with CONFIG_DEVTMPFS!"
+    exit 1
+fi
+
 # prepare the /dev directory
 [ ! -h /dev/fd ] && ln -s /proc/self/fd /dev/fd >/dev/null 2>&1
 [ ! -h /dev/stdin ] && ln -s /proc/self/fd/0 /dev/stdin >/dev/null 2>&1
@@ -66,6 +79,8 @@ if ! ismounted /run; then
     rm -fr /newrun
 fi
 
+trap "emergency_shell Signal caught!" 0
+
 [ -d /run/initramfs ] || mkdir -p -m 0755 /run/initramfs
 
 UDEVVERSION=$(udevadm --version)