it solves the following case:
root=/dev/nfs nfsroot=server:/path
- the server could be reachable on any interface
- any interface can get an IP by dhcp
- only one IP is allowed to mount the root
Udev rules set a /dev/root symlink to the real root and add
a mount script to /mount/. This enables the proper use of pre-mount
scripts and prevents mount being killed by a udev timeout.
This introduces detailed cmdline parsing, warning or aborting if the
cmdline does not contain arguments according to the spec.
Makeing sure the parsers don't just call getarg for netroot et al,
allows their reuse inside netroot to analyse dhcp root-path as well.
Hence we can get rid of the current netroot hooks. The hook itself stays
in order to add further modules which should run before netroot handlers
are called.
This has one drawback: nfsroot needs some more logic to handle nfs
specific data inside dhcp root-path.
The parsers have been writting according to current discussions about
cmdline arguments. This lead to the "discovery" that some test-cases
violate the spec. These tests have not been removed, but change to
"must fail".
Multiline conditionals ( && { ... } ) should use if, function
declarations go to the top of the file, add/update comments and remove
some unnecessary clutter.
This is probably not necessary, but paranoia dictates that the actual
netroot handlers should check if all three required arguments (netif,
root, NEWROOT) are there and useable.
rpc.statd is only needed for NFSv4, because it's required for
locking. We don't support locking for NFSv2/3, so start it only
if we are mount from NFSv4.
This patch enhances nfsroot and the nfs test-suite with compatibility
for debian based distros. This is mainly the difference of using
portmap instead of rpcbind and the missing file /etc/netconfig
This implements a default path of /tftpboot/%s if no path is provided,
and adds host name substitution for %s, with a fall back to the IP address,
as provided by the kernel's nfsroot handling.
The test suite is updated to test this functionality.
Probe for NFS and NBD capability before trying to load their modules
in case they are built into the kernel. Ugly use of flag files, but
avoids the need for grep to be on the image.
Parse and convert commandline options in the cmdline hook, and
fill in the missing pieces in the netroot hook. This also allows
root=dhcp to work as expected.
Work-in-progress to mount NFS root from udev, using the DHCP options and
allowing an override from the kernel command line. Supports NFSv4 w/locking
and NFSv2/v3 with nolock.
This is just an RFC patch, you'll note all the XXX markings where I've been
thinking about how to best do things. In addition, we really want to retry
DHCP and NFS mounting in a loop, in case the servers are down or overloaded
like when booting a full diskless cluster.
Harald Hoyer