dracut/modules.d/95nfs/nfsroot

#!/bin/sh

. /lib/dracut-lib

PATH=$PATH:/sbin:/usr/sbin

# XXX needs error handling like ifup/dhclient-script

# XXX need to lock our attempts if we're doing the mount here

getarg rdnetdebug && {
    exec > /tmp/nfsroot.$1.$$.out
    exec 2>> /tmp/nfsroot.$1.$$.out
    set -x
}

[ "$NFS_LOCKED" ] || {
	NFS_LOCKED=true
	export NFS_LOCKED
	exec flock -xo /tmp/nfs.lock -c "$0 $*"
	exit 1
}

[ -e /tmp/nfsdone ] && exit 0

nfs_done() {
    >/tmp/nfsdone
    exit 0
}

root=$(getarg root)
case $root in
    nfs|/dev/nfs)	type=nfs  ;;
    nfs4|/dev/nfs4)	type=nfs4 ;;
    auto|'')		type=auto  ;;
esac

rootfstype=$(getarg rootfstype)
case $rootfstype in
    nfs|nfs4|auto)	type=$rootfstype  ;;
esac

# If we're not doing NFS at all, don't keep banging our head
[ -n "$type" ] || nfs_done

[ -e /tmp/net.$1.dhcpopts ] && . /tmp/net.$1.dhcpopts

nfsroot=$(getarg nfsroot)
[ -n "$nfsroot" ] || nfsroot="$new_root_path"
[ -n "$nfsroot" ] || nfs_done

# check for IP address at front, if there is none, use
# new_dhcp_server_identifier
#
# XXX kernel nfsroot uses , to separate NFS options at end
#
nfsserver=${nfsroot%%:*}; nfsroot=${nfsroot#*:}
nfspath=${nfsroot%%:*}
flags=${nfsroot#*:}
[ "$nfsserver" = "$nfspath" ] && nfsserver=$new_dhcp_server_identifier
[ "$nfspath" = "$flags" ] && unset flags

[ -n "$nfsserver" ] || no_nfs

# look through the flags and see if any are overridden by the command line
while [ -n "$flags" ]; do
    f=${flags%%,*}; flags=${flags#*,}
    [ "$f" = "nfs" -o "$f" = "nfs4" ] && {
	[ "$type" = "auto" ] && type=$f
	continue
    }
    [ "$f" = "ro" -o "$f" = "rw" ] && {
	nfsrw=$f
	continue
    }
    [ "$f" = "lock" -o "$f" = "nolock" ] && {
	nfslock=$f
	continue
    }
    nfsflags=${nfsflags+$nfsflags,}$f
done

getarg ro && nfsrw=ro
getarg rw && nfsrw=rw
nfsflags=${nfsflags+$nfsflags,}${nfsrw}

# load our modules explicitly, so we can fail fast in the future
modprobe nfs || nfs_done

# XXX don't forget to move /var/lib/nfs/rpc_pipefs to new /
# XXX need host name set before now?

# Start rpcbind and rpc.statd as mount won't let us use locks on a NFSv4
# filesystem without talking to them, even though they are unneeded
# XXX occasionally saw 'rpcbind: fork failed: No such device' -- why?
[ -n "$(pidof rpcbind)" ] || rpcbind
[ -n "$(pidof rpc.statd)" ] || rpc.statd

# XXX should I do rpc.idmapd here, or wait and start in the new root
# XXX waiting assumes root can read everything it needs right up until
# XXX we start it...

# XXX really, want to retry in a loop I think, but not here...

[ "$type" = "nfs4" -o "$type" = "auto" ] && {
    # XXX really needed? Do we need non-root users before we start it in
    # XXX the real root image?
    [ -n "$(pidof rpc.idmapd)" ] || rpc.idmapd

    # NFSv4 does locks internally
    mount -t nfs4 -o${nfsflags}${nfslock+,$nfslock} \
			$nfsserver:$nfspath /sysroot && nfs_done

    # If we're specified to be NFSv4, then stop when we fail
    # Don't mark us done, as this may be transient
    [ "$type" = "nfs4" ] && exit 0
}

# we're NFSv{2,3} or auto and NFSv4 failed. We don't support using locks
# on NFSv{2,3} because that requires a helper to transfer the rpcbind state
# rpcbind to the new root
[ -z "$nfslock" -o "$nfslock" = "lock" ] &&
    echo "Locks unsupported on NFSv{2,3}, using nolock" 1>&2
mount -t nfs -onolock,$nfsflags $nfsserver:$nfspath /sysroot && nfs_done
exit 0