overlayfs-etc: add option to skip creation of mount dirs

The 'preinit' script can't create mount directories when rootfs is
read-only. Add an option to skip this step. The user must make sure that
all required directories are already in the rootfs directory layout.

Cc: Vyacheslav Yurkov <uvv.mail@gmail.com>
(From OE-Core rev: 302dd4a63f97e23631a62a0b902cc253f6843ab0)

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit 3d433d8559467d255bd19af2d0999c65ea24a48d)
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 13 insertions, 8 deletions

diff --git a/meta/classes/overlayfs-etc.bbclass b/meta/classes/overlayfs-etc.bbclass
index 40116e4c6e..7096aae1a8 100644
--- a/meta/classes/overlayfs-etc.bbclass
+++ b/meta/classes/overlayfs-etc.bbclass
@@ -35,6 +35,7 @@ OVERLAYFS_ETC_USE_ORIG_INIT_NAME ??= "1"
 OVERLAYFS_ETC_MOUNT_OPTIONS ??= "defaults"
 OVERLAYFS_ETC_INIT_TEMPLATE ??= "${COREBASE}/meta/files/overlayfs-etc-preinit.sh.in"
 OVERLAYFS_ETC_EXPOSE_LOWER ??= "0"
+OVERLAYFS_ETC_CREATE_MOUNT_DIRS ??= "1"
 
 python create_overlayfs_etc_preinit() {
     overlayEtcMountPoint = d.getVar("OVERLAYFS_ETC_MOUNT_POINT")
@@ -56,6 +57,7 @@ python create_overlayfs_etc_preinit() {
     initBaseName = oe.path.join(d.getVar("base_sbindir"), "init")
     origInitNameSuffix = ".orig"
     exposeLower = oe.types.boolean(d.getVar('OVERLAYFS_ETC_EXPOSE_LOWER'))
+    createMoundDirs = oe.types.boolean(d.getVar('OVERLAYFS_ETC_CREATE_MOUNT_DIRS'))
 
     args = {
         'OVERLAYFS_ETC_MOUNT_POINT': overlayEtcMountPoint,
@@ -63,7 +65,8 @@ python create_overlayfs_etc_preinit() {
         'OVERLAYFS_ETC_FSTYPE': overlayEtcFsType,
         'OVERLAYFS_ETC_DEVICE': overlayEtcDevice,
         'SBIN_INIT_NAME': initBaseName + origInitNameSuffix if useOrigInit else initBaseName,
-        'OVERLAYFS_ETC_EXPOSE_LOWER': "true" if exposeLower else "false"
+        'OVERLAYFS_ETC_EXPOSE_LOWER': "true" if exposeLower else "false",
+        'CREATE_MOUNT_DIRS': "true" if createMoundDirs else "false"
     }
 
     if useOrigInit:
diff --git a/meta/files/overlayfs-etc-preinit.sh.in b/meta/files/overlayfs-etc-preinit.sh.in
index 8db076f4ba..b05e3957a3 100644
--- a/meta/files/overlayfs-etc-preinit.sh.in
+++ b/meta/files/overlayfs-etc-preinit.sh.in
@@ -3,12 +3,15 @@
 echo "PREINIT: Start"
 
 PATH=/sbin:/bin:/usr/sbin:/usr/bin
-mount -o remount,rw /
-
-mkdir -p /proc
-mkdir -p /sys
-mkdir -p /run
-mkdir -p /var/run
+if {CREATE_MOUNT_DIRS}; then
+    mount -o remount,rw /
+
+    mkdir -p /proc
+    mkdir -p /sys
+    mkdir -p /run
+    mkdir -p /var/run
+    mkdir -p {OVERLAYFS_ETC_MOUNT_POINT}
+fi
 
 mount -t proc proc /proc
 mount -t sysfs sysfs /sys
@@ -20,7 +23,6 @@ UPPER_DIR=$BASE_OVERLAY_ETC_DIR/upper
 WORK_DIR=$BASE_OVERLAY_ETC_DIR/work
 LOWER_DIR=$BASE_OVERLAY_ETC_DIR/lower
 
-mkdir -p {OVERLAYFS_ETC_MOUNT_POINT}
 if mount -n -t {OVERLAYFS_ETC_FSTYPE} \
     -o {OVERLAYFS_ETC_MOUNT_OPTIONS} \
     {OVERLAYFS_ETC_DEVICE} {OVERLAYFS_ETC_MOUNT_POINT}