On Fri, Dec 27, 2013 at 1:44 PM, Holger Schurig <[email protected]> wrote: > If I place an empty /etc/machine-id into the image, then > /run/machine-id will be bind-mounted over it. > > But that file will be different whenever I boot. So obviously I want > to save it, once my filesystem is fsck'd and mounted read-write. But > if I do it like that ...
Yes, it's a privacy feature, it should do that: empty file --> random id. > umount /etc/machine-id > cp /run/machine-id /etc/machine-id > > ... then and between step 1 and 2 some other process might fall on > it's nose. I noticed that several systemd binaries directly access > /etc/machine-id via sd_id128_get_machine(). That would mean a race > condition, or? Yes, you can mount the root block device to a different place a second time, and should be able to unlink the file and replace it, then umount the file on the real /, and all should be atomic. >> You should always mount a tmpfs as /run, it is not supposed to be the >> same as /. Omitting the /run tmpfs mount is not supported. > > Kay, you're replaying to my point 3. that I already have "taken back" > :-) And no, I should *NOT* mount it --- how could I, without an > initrd? I don't need to mount it, because systemd mounts it for me > with one of the functions in src/core/mount-setup.c before calling > machine_id_setup(). Yeah, I was replying to your "/run is still on the same partition as /" which sounded like you did something, what systemd itself makes sure would not happen. Kay _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
