base-files: add support for rootfs mount options from cmdline

Add support for configuring rootfs mount options from cmdline.

Rootfs mount options can be passed by declaring in the kernel
cmdline as much options as needed prefixed with "rootfs_mount_options."

An example usage is with rootfs with F2FS filesystem to enable
compress_algorithm to reduce flash wear by compressing the files before
writing to flash.

Example usage:
"... rootfs_mount_options.compress_algorithm=zstd ..."

To pass multiple options:
"... rootfs_mount_options.compress_algorithm=zstd rootfs_mount_options.noinline_data ..."

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/package/base-files/files/lib/preinit/80_mount_root b/package/base-files/files/lib/preinit/80_mount_root
index c3816c2cbfe11a1f4e2091f4e7ef5c6791f7d308..fa6abcde57f850a3b1d4cf6ed83d5e4031266f59 100644 (file)
--- a/package/base-files/files/lib/preinit/80_mount_root
+++ b/package/base-files/files/lib/preinit/80_mount_root
@@ -14,8 +14,27 @@ missing_lines() {
        IFS="$oIFS"
 }
 
+# Rootfs mount options can be passed by declaring in the kernel
+# cmdline as much options as needed prefixed with "rootfs_mount_options."
+#
+# Example:
+# rootfs_mount_options.compress_algorithm=zstd rootfs_mount_options.noinline_data
+#
+compose_rootfs_mount_options() {
+       local mount_options
+       local cmdlinevar
+
+       for cmdlinevar in $(cat /proc/cmdline); do
+               if [ "$cmdlinevar" != "${cmdlinevar#rootfs_mount_options\.}" ]; then
+                       append mount_options "${cmdlinevar#rootfs_mount_options\.}"
+               fi
+       done
+
+       echo $mount_options
+}
+
 do_mount_root() {
-       mount_root
+       mount_root start "$(compose_rootfs_mount_options)"
        boot_run_hook preinit_mount_root
        [ -f /sysupgrade.tgz -o -f /tmp/sysupgrade.tar ] && {
                echo "- config restore -"