Messages in this thread | | | From | Roberto Sassu <> | Subject | RE: [PATCH v4 0/3] initramfs: add support for xattrs in the initial ram disk | Date | Tue, 19 Jul 2022 12:26:02 +0000 |
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> From: Rob Landley [mailto:rob@landley.net] > Sent: Tuesday, July 19, 2022 1:51 PM > On 7/19/22 01:55, Roberto Sassu wrote: > >> Thank you, I have tested that patch but the problem remained. Here is my > >> command line, I wonder if there is something wrong. > >> > >> Kernel command line: rw rootfstype=initramtmpfs root=/dev/ram0 > >> initrd=0x500000000 rootwait > > > > It is just initramtmpfs, without rootfstype=. > > Whoever wrote that patch really doesn't understand how this stuff works. I can > tell from the name.
Hi Rob
surely, I should have been more careful in choosing the name of the option.
> Technically, initramfs is the loader, I.E. "init ramfs". The filesystem instance > is called "rootfs" (hence the name in /proc/mounts when the insane special case > the kernel added doesn't hide information from people, making all this harder to > understand for no obvious reason).
Ok, thanks for the explanation.
> ramfs and tmpfs are two different filesystems that COULD be used to implement > rootfs. (Last I checked they were the only ram backed filesystems in Linux.)
Yes, that part I got it.
> If a system administrator says they're going to install your server's root > partition using the "reiserxfs" filesystem, I would not be reassured.
Definitely.
[...]
> P.P.S. If you want to run a command other than /init out of initramfs or initrd, > use the rdinit=/run/this option. Note the root= overmount mechanism is > completely different code and uses the init=/run/this argument instead, which > means nothing to initramfs. Again, specifying root= says we are NOT staying in > initramfs.
Sorry, it was some time ago. I have to go back and see why we needed a separate option. Maybe omitting root= was impacting on mounting the real root filesystem. Will get that information.
Intuitively, given that root= is consumed for example by dracut, it seems a safer choice to have an option to explicitly choose the desired filesystem.
Roberto
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