rc.initdiskless revision 161824
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 161824 2006-09-01 16:33:15Z brooks $ 28 29# On entry to this script the entire system consists of a read-only root 30# mounted via NFS. The kernel has run BOOTP and configured an interface 31# (otherwise it would not have been able to mount the NFS root!) 32# 33# We use the contents of /conf to create and populate memory filesystems 34# that are mounted on top of this root to implement the writable 35# (and host-specific) parts of the root filesystem, and other volatile 36# filesystems. 37# 38# The hierarchy in /conf has the form /conf/T/M/ where M are directories 39# for which memory filesystems will be created and filled, 40# and T is one of the "template" directories below: 41# 42# base universal base, typically a replica of the original root; 43# default secondary universal base, typically overriding some 44# of the files in the original root; 45# ${ipba} where ${ipba} is the assigned broadcast IP address 46# bcast/${ipba} same as above 47# ${class} where ${class} is a list of directories supplied by 48# bootp/dhcp through the T134 option. 49# ${ipba} and ${class} are typicall used to configure features 50# for group of diskless clients, or even individual features; 51# ${ip} where ${ip} is the machine's assigned IP address, typically 52# used to set host-specific features; 53# ip/${ip} same as above 54# 55# Template directories are scanned in the order they are listed above, 56# with each sucessive directory overriding (merged into) the previous one; 57# non-existing directories are ignored. The subdirectory forms exist to 58# help keep the top level /conf managable in large installations. 59# 60# The existence of a directory /conf/T/M causes this script to create a 61# memory filesystem mounted as /M on the client. 62# 63# Some files in /conf have special meaning, namely: 64# 65# Filename Action 66# ---------------------------------------------------------------- 67# /conf/T/M/remount 68# The contents of the file is a mount command. E.g. if 69# /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3", 70# then /dev/ad0s3 will be be mounted on /conf/1.2.3.4/foo/ 71# 72# /conf/T/M/diskless_remount 73# The contents of the file points to an NFS filesystem. E.g. if 74# /conf/base/etc/diskless_remount contains "foo.com:/etc", 75# then foo.com:/etc will be be mounted on /conf/base/etc/ 76# If the file contains a pathname starting with "/", then 77# the root path is prepended to it; this allows relocation of 78# the root filesystem without changing configuration files. 79# Because mount_nfs understands ".." in paths, it is 80# possible to mount from locations above the NFS root with 81# paths such as "/../../etc". 82# 83# /conf/T/M/md_size 84# The contents of the file specifies the size of the memory 85# filesystem to be created, in 512 byte blocks. 86# The default size is 10240 blocks (5MB). E.g. if 87# /conf/base/etc/md_size contains "30000" then a 15MB MFS 88# will be created. In case of multiple entries for the same 89# directory M, the last one in the scanning order is used. 90# NOTE: If you only need to create a memory filesystem but not 91# initialize it from a template, it is preferrable to specify 92# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" 93# 94# /conf/T/SUBDIR.cpio.gz 95# The file is cpio'd into /SUBDIR (and a memory filesystem is 96# created for /SUBDIR if necessary). The presence of this file 97# prevents the copy from /conf/T/SUBDIR/ 98# 99# /conf/T/SUBDIR.remove 100# The list of paths contained in the file are rm -rf'd 101# relative to /SUBDIR. 102# 103# /conf/diskless_remount 104# Similar to /conf/T/M/diskless_remount above, but allows 105# all of /conf to be remounted. This can be used to allow 106# multiple roots to share the same /conf. 107# 108# 109# You will almost universally want to create the following files under /conf 110# 111# File Content 112# ---------------------------- ---------------------------------- 113# /conf/base/etc/md_size size of /etc filesystem 114# /conf/base/etc/diskless_remount "/etc" 115# /conf/default/etc/rc.conf generic diskless config parameters 116# /conf/default/etc/fstab generic diskless fstab e.g. like this 117# 118# foo:/root_part / nfs ro 0 0 119# foo:/usr_part /usr nfs ro 0 0 120# foo:/home_part /home nfs rw 0 0 121# md /tmp mfs -s=30m,rw 0 0 122# md /var mfs -s=30m,rw 0 0 123# proc /proc procfs rw 0 0 124# 125# plus, possibly, overrides for password files etc. 126# 127# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. 128# as entries in the fstab as above. 129# Those filesystems should not be specified in /conf. 130# 131# (end of documentation, now get to the real code) 132 133dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` 134 135# chkerr: 136# 137# Routine to check for error 138# 139# checks error code and drops into shell on failure. 140# if shell exits, terminates script as well as /etc/rc. 141# 142chkerr() { 143 case $1 in 144 0) 145 ;; 146 *) 147 echo "$2 failed: dropping into /bin/sh" 148 /bin/sh 149 # RESUME 150 ;; 151 esac 152} 153 154# Create a generic memory disk 155# 156mount_md() { 157 /sbin/mdmfs -S -i 4096 -s $1 -M md $2 158} 159 160# Create the memory filesystem if it has not already been created 161# 162create_md() { 163 if [ "x`eval echo \\$md_created_$1`" = "x" ]; then 164 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then 165 md_size=10240 166 else 167 md_size=`eval echo \\$md_size_$1` 168 fi 169 mount_md $md_size /$1 170 /bin/chmod 755 /$1 171 eval md_created_$1=created 172 fi 173} 174 175# DEBUGGING 176# 177# set -v 178 179# Figure out our interface and IP. 180# 181bootp_ifc="" 182bootp_ipa="" 183bootp_ipbca="" 184class="" 185if [ ${dlv:=0} -ne 0 ] ; then 186 iflist=`ifconfig -l` 187 for i in ${iflist} ; do 188 set -- `ifconfig ${i}` 189 while [ $# -ge 1 ] ; do 190 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then 191 bootp_ifc=${i} ; bootp_ipa=${2} ; shift 192 fi 193 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then 194 bootp_ipbca=$2; shift 195 fi 196 shift 197 done 198 if [ "${bootp_ifc}" != "" ] ; then 199 break 200 fi 201 done 202 # Get the values passed with the T134 bootp cookie. 203 class="`/sbin/sysctl -qn kern.bootp_cookie`" 204 205 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}" 206fi 207 208# Figure out our NFS root path 209# 210set -- `mount -t nfs` 211while [ $# -ge 1 ] ; do 212 if [ "$2" = "on" -a "$3" = "/" ]; then 213 nfsroot="$1" 214 break 215 fi 216 shift 217done 218 219# The list of directories with template files 220templates="base default" 221if [ -n "${bootp_ipbca}" ]; then 222 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}" 223fi 224if [ -n "${class}" ]; then 225 templates="${templates} ${class}" 226fi 227if [ -n "${bootp_ipa}" ]; then 228 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}" 229fi 230 231# The list of filesystems to umount after the copy 232to_umount="" 233 234# If /conf/diskless_remount exists, remount all of /conf. 235if [ -d /conf -a -f /conf/diskless_remount ]; then 236 nfspt=`/bin/cat /conf/diskless_remount` 237 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 238 nfspt="${nfsroot}${nfspt}" 239 fi 240 mount_nfs $nfspt /conf 241 chkerr $? "mount_nfs $nfspt /conf" 242 to_umount="/conf" 243fi 244 245# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, 246# and /conf/${bootp_ipa}. For each subdirectory found within these 247# directories: 248# 249# - calculate memory filesystem sizes. If the subdirectory (prior to 250# NFS remounting) contains the file 'md_size', the contents specified 251# in 512 byte sectors will be used to size the memory filesystem. Otherwise 252# 8192 sectors (4MB) is used. 253# 254# - handle NFS remounts. If the subdirectory contains the file 255# diskless_remount, the contents of the file is NFS mounted over 256# the directory. For example /conf/base/etc/diskless_remount 257# might contain 'myserver:/etc'. NFS remounts allow you to avoid 258# having to dup your system directories in /conf. Your server must 259# be sure to export those filesystems -alldirs, however. 260# If the diskless_remount file contains a string beginning with a 261# '/' it is assumed that the local nfsroot should be prepended to 262# it before attemping to the remount. This allows the root to be 263# relocated without needing to change the remount files. 264# 265for i in ${templates} ; do 266 for j in /conf/$i/* ; do 267 # memory filesystem size specification 268 # 269 subdir=${j##*/} 270 if [ -d $j -a -f $j/md_size ]; then 271 eval md_size_$subdir=`cat $j/md_size` 272 fi 273 274 # remount 275 # 276 if [ -d $j -a -f $j/remount ]; then 277 nfspt=`/bin/cat $j/remount` 278 $nfspt $j 279 chkerr $? "$nfspt $j" 280 to_umount="$j ${to_umount}" # XXX hope it is really a mount! 281 fi 282 283 # NFS remount 284 # 285 if [ -d $j -a -f $j/diskless_remount ]; then 286 nfspt=`/bin/cat $j/diskless_remount` 287 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 288 nfspt="${nfsroot}${nfspt}" 289 fi 290 mount_nfs $nfspt $j 291 chkerr $? "mount_nfs $nfspt $j" 292 to_umount="$j ${to_umount}" 293 fi 294 done 295done 296 297# - Create all required MFS filesystems and populate them from 298# our templates. Support both a direct template and a dir.cpio.gz 299# archive. Support dir.remove files containing a list of relative 300# paths to remove. 301# 302# The dir.cpio.gz form is there to make the copy process more efficient, 303# so if the cpio archive is present, it prevents the files from dir/ 304# from being copied. 305 306for i in ${templates} ; do 307 for j in /conf/$i/* ; do 308 subdir=${j##*/} 309 if [ -d $j -a ! -f $j.cpio.gz ]; then 310 create_md $subdir 311 cp -Rp $j/ /$subdir 312 fi 313 done 314 for j in /conf/$i/*.cpio.gz ; do 315 subdir=${j%*.cpio.gz} 316 subdir=${subdir##*/} 317 if [ -f $j ]; then 318 create_md $subdir 319 echo "Loading /$subdir from cpio archive $j" 320 (cd / ; /rescue/tar -xpf $j) 321 fi 322 done 323 for j in /conf/$i/*.remove ; do 324 subdir=${j%*.remove} 325 subdir=${subdir##*/} 326 if [ -f $j ]; then 327 # doubly sure it is a memory disk before rm -rf'ing 328 create_md $subdir 329 (cd /$subdir; rm -rf `/bin/cat $j`) 330 fi 331 done 332done 333 334# umount partitions used to fill the memory filesystems 335[ -n "${to_umount}" ] && umount $to_umount 336