Bug 427998

Summary:	sys-apps/openrc: The root script does not work correctly if root or any filesystems it remounts are nfs
Product:	Gentoo Hosted Projects	Reporter:	Dennis Schridde <dschridde+gentoobugs>
Component:	OpenRC	Assignee:	OpenRC Team <openrc>
Status:	UNCONFIRMED ---
Severity:	normal	CC:	pchrist
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://bugzilla.redhat.com/show_bug.cgi?id=537969#c18
Whiteboard:
Package list:		Runtime testing required:	---
Attachments:	patch for root init script (NFS /)

Description Dennis Schridde 2012-07-25 08:42:17 UTC

If rootfs is nfs4, OpenRC needs to start rpc.idmapd as early as possible — especially before it does any writing on the filesystem. (See [1])

Currently it gets itself stuck: rootfs is mounted ro by the initrd, openrc cannot execute mount because that is suid and, due to the lack of idmapd, owned by -1, so it cannot remount the rootfs.
After remounting the rootfs, it then seems to see the service dependency cache outdated and tries to regenerate, which is not possible on a ro rootfs… I think it should panic instead, because the dirs it needs to operate are not writable.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=537969#c18

Reproducible: Always

Comment 1 William Hubbs gentoo-dev

2012-09-10 17:54:19 UTC

I am duping this to your original bug. If you disagree, please feel free
to re-open.

*** This bug has been marked as a duplicate of bug 427996 ***

Comment 2 William Hubbs gentoo-dev

2012-09-12 00:42:36 UTC

This bug actually applies if any filesystem the root script attempts to
remount is nfs or nfsv4, so I am generalizing it.

Comment 3 Dennis Schridde 2012-10-18 17:42:12 UTC

Since bug #427996 was fixed by requiring the user to use nfsmount instead of netmount, can this be fixed in a similar way? Is it possible to make root depend on nfsmount if / is nfs?

Comment 4 Panagiotis Christopoulos (RETIRED) gentoo-dev

2013-03-16 22:19:31 UTC

Created attachment 342306 [details, diff]
patch for root init script (NFS /)

I had the same problem and fixed it with the cc'd patch. It seems that mount calls mount.nfs which can do "remount,rw" only without passing other options to -o . It also needs the absolute path of the remote directory (at least, that's how it worked for me).

@William, this is a nasty hack, and I haven't tested it thoroughly. Didn't find time to check the code inside util-linux and nfs-utils for better alternatives yet.