rc.initdiskless revision 128706
1#!/bin/sh 2# 3# Copyright (c) 1999 Matt Dillon 4# All rights reserved. 5# 6# Redistribution and use in source and binary forms, with or without 7# modification, are permitted provided that the following conditions 8# are met: 9# 1. Redistributions of source code must retain the above copyright 10# notice, this list of conditions and the following disclaimer. 11# 2. Redistributions in binary form must reproduce the above copyright 12# notice, this list of conditions and the following disclaimer in the 13# documentation and/or other materials provided with the distribution. 14# 15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25# SUCH DAMAGE. 26# 27# $FreeBSD: head/etc/rc.initdiskless 128706 2004-04-28 09:09:27Z ru $ 28# 29# REQUIRE: preseedrandom 30# PROVIDE: initdiskless 31# KEYWORD: FreeBSD nojail 32 33 34# On entry to this script the entire system consists of a read-only root 35# mounted via NFS. The kernel has run BOOTP and configured an interface 36# (otherwise it would not have been able to mount the NFS root!) 37# 38# We use the contents of /conf to create and populate memory filesystems 39# that are mounted on top of this root to implement the writable 40# (and host-specific) parts of the root filesystem, and other volatile 41# filesystems. 42# 43# The hierarchy in /conf has the form /conf/T/M/ where M are directories 44# for which memory filesystems will be created and filled, 45# and T is one of the "template" directories below: 46# 47# base universal base, typically a replica of the original root; 48# default secondary universal base, typically overriding some 49# of the files in the original root; 50# ${ipba} where ${ipba} is the assigned broadcast IP address 51# ${class} where ${class} is a list of directories supplied by 52# bootp/dhcp through the T134 option. 53# ${ipba} and ${class} are typicall used to configure features 54# for group of diskless clients, or even individual features; 55# ${ip} where ${ip} is the machine's assigned IP address, typically 56# used to set host-specific features; 57# 58# Template directories are scanned in the order they are listed above, 59# with each sucessive directory overriding (merged into) the previous one; 60# non-existing directories are ignored. 61# 62# The existence of a directory /conf/T/M causes this script to create a 63# memory filesystem mounted as /M on the client. 64# 65# Some files in /conf have special meaning, namely: 66# 67# Filename Action 68# ---------------------------------------------------------------- 69# /conf/T/M/remount 70# The contents of the file is a mount command. E.g. if 71# /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3", 72# then /dev/ad0s3 will be be mounted on /conf/1.2.3.4/foo/ 73# 74# /conf/T/M/diskless_remount 75# The contents of the file points to an NFS filesystem. E.g. if 76# /conf/base/etc/diskless_remount contains "foo.com:/etc", 77# then foo.com:/etc will be be mounted on /conf/base/etc/ 78# If the file contains a pathname starting with "/", then 79# the root path is prepended to it; this allows relocation of 80# the root filesystem withouth changing configuration files. 81# 82# /conf/T/M/md_size 83# The contents of the file specifies the size of the memory 84# filesystem to be created, in 512 byte blocks. 85# The default size is 10240 blocks (5MB). E.g. if 86# /conf/base/etc/md_size contains "30000" then a 15MB MFS 87# will be created. In case of multiple entries for the same 88# directory M, the last one in the scanning order is used. 89# NOTE: If you only need to create a memory filesystem but not 90# initialize it from a template, it is preferrable to specify 91# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" 92# 93# /conf/T/SUBDIR.cpio.gz 94# The file is cpio'd into /SUBDIR (and a memory filesystem is 95# created for /SUBDIR if necessary). The presence of this file 96# prevents the copy from /conf/T/SUBDIR/ 97# 98# /conf/T/SUBDIR.remove 99# The list of paths contained in the file are rm -rf'd 100# relative to /SUBDIR. 101# 102# You will almost universally want to create the following files under /conf 103# 104# File Content 105# ---------------------------- ------------------------------------------ 106# /conf/base/etc/md_size size of /etc filesystem 107# /conf/base/diskless_remount "/etc" 108# /conf/default/etc/rc.conf generic diskless config parameters 109# /conf/default/etc/fstab generic diskless fstab e.g. like this 110# 111# foo:/root_part / nfs ro 0 0 112# foo:/usr_part /usr nfs ro 0 0 113# foo:/home_part /home nfs rw 0 0 114# md /tmp mfs -s=30m,rw 0 0 115# md /var mfs -s=30m,rw 0 0 116# proc /proc procfs rw 0 0 117# 118# plus, possibly, overrides for password files etc. 119# 120# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. 121# as entries in the fstab as above. 122# Those filesystems should not be specified in /conf. 123# 124# (end of documentation, now get to the real code) 125 126dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` 127[ ${dlv:=0} -eq 0 ] && [ ! -f /etc/diskless ] && exit 0 128 129# chkerr: 130# 131# Routine to check for error 132# 133# checks error code and drops into shell on failure. 134# if shell exits, terminates script as well as /etc/rc. 135# 136chkerr() { 137 case $1 in 138 0) 139 ;; 140 *) 141 echo "$2 failed: dropping into /bin/sh" 142 /bin/sh 143 # RESUME 144 ;; 145 esac 146} 147 148# Create a generic memory disk 149# 150mount_md() { 151 /sbin/mdmfs -i 4096 -s $1 -M md $2 152} 153 154# Create the memory filesystem if it has not already been created 155# 156create_md() { 157 if [ "x`eval echo \\$md_created_$1`" = "x" ]; then 158 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then 159 md_size=10240 160 else 161 md_size=`eval echo \\$md_size_$1` 162 fi 163 mount_md $md_size /$1 164 /bin/chmod 755 /$1 165 eval md_created_$1=created 166 fi 167} 168 169# DEBUGGING 170# 171# set -v 172 173# Figure out our interface and IP. 174# 175bootp_ifc="" 176bootp_ipa="" 177bootp_ipbca="" 178if [ ${dlv:=0} -ne 0 ] ; then 179 iflist=`ifconfig -l` 180 for i in ${iflist} ; do 181 set -- `ifconfig ${i}` 182 while [ $# -ge 1 ] ; do 183 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then 184 bootp_ifc=${i} ; bootp_ipa=${2} ; shift 185 fi 186 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then 187 bootp_ipbca=$2; shift 188 fi 189 shift 190 done 191 if [ "${bootp_ifc}" != "" ] ; then 192 break 193 fi 194 done 195 # Insert the directories passed with the T134 bootp cookie 196 # in the list of paths used for templates. 197 i="`/sbin/sysctl -n kern.bootp_cookie`" 198 [ "${i}" != "" ] && bootp_ipbca="${bootp_ipbca} ${i}" 199 200 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}" 201fi 202 203# Figure out our NFS root path 204# 205set -- `mount -t nfs` 206while [ $# -ge 1 ] ; do 207 if [ "$2" = "on" -a "$3" = "/" ]; then 208 nfsroot="$1" 209 break 210 fi 211 shift 212done 213 214# The list of directories with template files 215templates="base default ${bootp_ipbca} ${bootp_ipa}" 216 217# The list of filesystems to umount after the copy 218to_umount="" 219 220# If /conf/diskless_remount exists, remount all of /conf. This allows 221# multiple roots to share the same conf files. 222if [ -d /conf -a -f /conf/diskless_remount ]; then 223 nfspt=`/bin/cat /conf/diskless_remount` 224 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 225 nfspt="${nfsroot}${nfspt}" 226 fi 227 mount_nfs $nfspt /conf 228 chkerr $? "mount_nfs $nfspt /conf" 229 to_umount="/conf" 230fi 231 232# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, 233# and /conf/${bootp_ipa}. For each subdirectory found within these 234# directories: 235# 236# - calculate memory filesystem sizes. If the subdirectory (prior to 237# NFS remounting) contains the file 'md_size', the contents specified 238# in 512 byte sectors will be used to size the memory filesystem. Otherwise 239# 8192 sectors (4MB) is used. 240# 241# - handle NFS remounts. If the subdirectory contains the file 242# diskless_remount, the contents of the file is NFS mounted over 243# the directory. For example /conf/base/etc/diskless_remount 244# might contain 'myserver:/etc'. NFS remounts allow you to avoid 245# having to dup your system directories in /conf. Your server must 246# be sure to export those filesystems -alldirs, however. 247# If the diskless_remount file contains a string beginning with a 248# '/' it is assumed that the local nfsroot should be prepended to 249# it before attemping to the remount. This allows the root to be 250# relocated without needing to change the remount files. 251# 252for i in ${templates} ; do 253 for j in /conf/$i/* ; do 254 # memory filesystem size specification 255 # 256 subdir=${j##*/} 257 if [ -d $j -a -f $j/md_size ]; then 258 eval md_size_$subdir=`cat $j/md_size` 259 fi 260 261 # remount 262 # 263 if [ -d $j -a -f $j/remount ]; then 264 nfspt=`/bin/cat $j/remount` 265 $nfspt $j 266 chkerr $? "$nfspt $j" 267 to_umount="${to_umount} $j" # XXX hope it is really a mount! 268 fi 269 270 # NFS remount 271 # 272 if [ -d $j -a -f $j/diskless_remount ]; then 273 nfspt=`/bin/cat $j/diskless_remount` 274 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 275 nfspt="${nfsroot}${nfspt}" 276 fi 277 mount_nfs $nfspt $j 278 chkerr $? "mount_nfs $nfspt $j" 279 to_umount="${to_umount} $j" 280 fi 281 done 282done 283 284# - Create all required MFS filesystems and populate them from 285# our templates. Support both a direct template and a dir.cpio.gz 286# archive. Support dir.remove files containing a list of relative 287# paths to remove. 288# 289# The dir.cpio.gz form is there to make the copy process more efficient, 290# so if the cpio archive is present, it prevents the files from dir/ 291# from being copied. 292 293for i in ${templates} ; do 294 for j in /conf/$i/* ; do 295 subdir=${j##*/} 296 if [ -d $j -a ! -f $j.cpio.gz ]; then 297 create_md $subdir 298 cp -Rp $j/* /$subdir 299 fi 300 done 301 for j in /conf/$i/*.cpio.gz ; do 302 subdir=${j%*.cpio.gz} 303 subdir=${subdir##*/} 304 if [ -f $j ]; then 305 create_md $subdir 306 echo "Loading /$subdir from cpio archive $j" 307 (cd / ; /stand/gzip -d < $j | /stand/cpio --extract -d ) 308 fi 309 done 310 for j in /conf/$i/*.remove ; do 311 subdir=${j%*.remove} 312 subdir=${subdir##*/} 313 if [ -f $j ]; then 314 # doubly sure it is a memory disk before rm -rf'ing 315 create_md $subdir 316 (cd /$subdir; rm -rf `/bin/cat $j`) 317 fi 318 done 319done 320 321# umount partitions used to fill the memory filesystems 322[ -n "${to_umount}" ] && umount $to_umount 323