Make part of read-only filesystem writable I have a filesystem on flash using jffs2. I would like to mount this filesystem read-only, except for a single folder that I would like to be writable. Is this possible without resorting to something like unionfs and the likes?

You can use a bind mount, although they are a bit finicky about permissions requiring you to mount and then remount the directory to get the correct permissions. The man page of mount suggests:


mount --bind olddir newdir
mount -o remount,rw newdir


however on my Arch system I need to do


mount --bind olddir newdir
mount -o remount,rw olddir newdir


If you only want the directory to be listed in one place you can over mount the directory


mount --bind olddir olddir
mount -o remount,rw olddir olddir