rc.initdiskless revision 164862
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 164862 2006-12-03 23:50:29Z luigi $ 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, 74# possibly followed by mount_nfs options. If the server name 75# is omitted, the script will prepend the root path used when 76# booting. E.g. if you booted from foo.com:/path/to/root, 77# an entry for /conf/base/etc/diskless_remount could be any of 78# foo.com:/path/to/root/etc 79# /etc -o ro 80# Because mount_nfs understands ".." in paths, it is 81# possible to mount from locations above the NFS root with 82# paths such as "/../../etc". 83# 84# /conf/T/M/md_size 85# The contents of the file specifies the size of the memory 86# filesystem to be created, in 512 byte blocks. 87# The default size is 10240 blocks (5MB). E.g. if 88# /conf/base/etc/md_size contains "30000" then a 15MB MFS 89# will be created. In case of multiple entries for the same 90# directory M, the last one in the scanning order is used. 91# NOTE: If you only need to create a memory filesystem but not 92# initialize it from a template, it is preferrable to specify 93# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" 94# 95# /conf/T/SUBDIR.cpio.gz 96# The file is cpio'd into /SUBDIR (and a memory filesystem is 97# created for /SUBDIR if necessary). The presence of this file 98# prevents the copy from /conf/T/SUBDIR/ 99# 100# /conf/T/SUBDIR.remove 101# The list of paths contained in the file are rm -rf'd 102# relative to /SUBDIR. 103# 104# /conf/diskless_remount 105# Similar to /conf/T/M/diskless_remount above, but allows 106# all of /conf to be remounted. This can be used to allow 107# multiple roots to share the same /conf. 108# 109# 110# You will almost universally want to create the following files under /conf 111# 112# File Content 113# ---------------------------- ---------------------------------- 114# /conf/base/etc/md_size size of /etc filesystem 115# /conf/base/etc/diskless_remount "/etc" 116# /conf/default/etc/rc.conf generic diskless config parameters 117# /conf/default/etc/fstab generic diskless fstab e.g. like this 118# 119# foo:/root_part / nfs ro 0 0 120# foo:/usr_part /usr nfs ro 0 0 121# foo:/home_part /home nfs rw 0 0 122# md /tmp mfs -s=30m,rw 0 0 123# md /var mfs -s=30m,rw 0 0 124# proc /proc procfs rw 0 0 125# 126# plus, possibly, overrides for password files etc. 127# 128# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. 129# as entries in the fstab as above. 130# Those filesystems should not be specified in /conf. 131# 132# (end of documentation, now get to the real code) 133 134dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` 135 136# DEBUGGING 137# log something on stdout if verbose. 138o_verbose=0 # set to 1 or 2 if you want more debugging 139log() { 140 [ ${o_verbose} -gt 0 ] && echo "*** $* ***" 141 [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo 142} 143 144# chkerr: 145# 146# Routine to check for error 147# 148# checks error code and drops into shell on failure. 149# if shell exits, terminates script as well as /etc/rc. 150# 151chkerr() { 152 case $1 in 153 0) 154 ;; 155 *) 156 echo "$2 failed: dropping into /bin/sh" 157 /bin/sh 158 # RESUME 159 ;; 160 esac 161} 162 163# The list of filesystems to umount after the copy 164to_umount="" 165 166handle_remount() { # $1 = mount point 167 local nfspt mountopts b 168 b=$1 169 log handle_remount $1 170 [ -d $b -a -f $b/diskless_remount ] || return 171 read nfspt mountopts < $b/diskless_remount 172 log "nfspt ${nfspt} mountopts ${mountopts}" 173 # prepend the nfs root if not present 174 [ `expr "$nfspt" : '\(.\)'` = "/" ] && nfspt="${nfsroot}${nfspt}" 175 mount_nfs $mountopts $nfspt $b 176 chkerr $? "mount_nfs $nfspt $b" 177 to_umount="$b ${to_umount}" 178} 179 180# Create a generic memory disk 181# 182mount_md() { 183 /sbin/mdmfs -S -i 4096 -s $1 -M md $2 184} 185 186# Create the memory filesystem if it has not already been created 187# 188create_md() { 189 [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once 190 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then 191 md_size=10240 192 else 193 md_size=`eval echo \\$md_size_$1` 194 fi 195 log create_md $1 with size $md_size 196 mount_md $md_size /$1 197 /bin/chmod 755 /$1 198 eval md_created_$1=created 199} 200 201# DEBUGGING 202# 203# set -v 204 205# Figure out our interface and IP. 206# 207bootp_ifc="" 208bootp_ipa="" 209bootp_ipbca="" 210class="" 211if [ ${dlv:=0} -ne 0 ] ; then 212 iflist=`ifconfig -l` 213 for i in ${iflist} ; do 214 set -- `ifconfig ${i}` 215 while [ $# -ge 1 ] ; do 216 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then 217 bootp_ifc=${i} ; bootp_ipa=${2} ; shift 218 fi 219 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then 220 bootp_ipbca=$2; shift 221 fi 222 shift 223 done 224 if [ "${bootp_ifc}" != "" ] ; then 225 break 226 fi 227 done 228 # Get the values passed with the T134 bootp cookie. 229 class="`/sbin/sysctl -qn kern.bootp_cookie`" 230 231 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}" 232fi 233 234log Figure out our NFS root path 235# 236set -- `mount -t nfs` 237while [ $# -ge 1 ] ; do 238 if [ "$2" = "on" -a "$3" = "/" ]; then 239 nfsroot="$1" 240 break 241 fi 242 shift 243done 244 245# The list of directories with template files 246templates="base default" 247if [ -n "${bootp_ipbca}" ]; then 248 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}" 249fi 250if [ -n "${class}" ]; then 251 templates="${templates} ${class}" 252fi 253if [ -n "${bootp_ipa}" ]; then 254 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}" 255fi 256 257# If /conf/diskless_remount exists, remount all of /conf. 258handle_remount /conf 259 260# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, 261# and /conf/${bootp_ipa}. For each subdirectory found within these 262# directories: 263# 264# - calculate memory filesystem sizes. If the subdirectory (prior to 265# NFS remounting) contains the file 'md_size', the contents specified 266# in 512 byte sectors will be used to size the memory filesystem. Otherwise 267# 8192 sectors (4MB) is used. 268# 269# - handle NFS remounts. If the subdirectory contains the file 270# diskless_remount, the contents of the file is NFS mounted over 271# the directory. For example /conf/base/etc/diskless_remount 272# might contain 'myserver:/etc'. NFS remounts allow you to avoid 273# having to dup your system directories in /conf. Your server must 274# be sure to export those filesystems -alldirs, however. 275# If the diskless_remount file contains a string beginning with a 276# '/' it is assumed that the local nfsroot should be prepended to 277# it before attemping to the remount. This allows the root to be 278# relocated without needing to change the remount files. 279# 280log "templates are ${templates}" 281for i in ${templates} ; do 282 for j in /conf/$i/* ; do 283 [ -d $j ] || continue 284 285 # memory filesystem size specification 286 subdir=${j##*/} 287 [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size` 288 289 # remount. Beware, the command is in the file itself! 290 if [ -f $j/remount ]; then 291 nfspt=`/bin/cat $j/remount` 292 $nfspt $j 293 chkerr $? "$nfspt $j" 294 to_umount="$j ${to_umount}" # XXX hope it is really a mount! 295 fi 296 297 # NFS remount 298 handle_remount $j 299 done 300done 301 302# - Create all required MFS filesystems and populate them from 303# our templates. Support both a direct template and a dir.cpio.gz 304# archive. Support dir.remove files containing a list of relative 305# paths to remove. 306# 307# The dir.cpio.gz form is there to make the copy process more efficient, 308# so if the cpio archive is present, it prevents the files from dir/ 309# from being copied. 310 311for i in ${templates} ; do 312 for j in /conf/$i/* ; do 313 subdir=${j##*/} 314 if [ -d $j -a ! -f $j.cpio.gz ]; then 315 create_md $subdir 316 cp -Rp $j/ /$subdir 317 fi 318 done 319 for j in /conf/$i/*.cpio.gz ; do 320 subdir=${j%*.cpio.gz} 321 subdir=${subdir##*/} 322 if [ -f $j ]; then 323 create_md $subdir 324 echo "Loading /$subdir from cpio archive $j" 325 (cd / ; /rescue/tar -xpf $j) 326 fi 327 done 328 for j in /conf/$i/*.remove ; do 329 subdir=${j%*.remove} 330 subdir=${subdir##*/} 331 if [ -f $j ]; then 332 # doubly sure it is a memory disk before rm -rf'ing 333 create_md $subdir 334 (cd /$subdir; rm -rf `/bin/cat $j`) 335 fi 336 done 337done 338 339# umount partitions used to fill the memory filesystems 340[ -n "${to_umount}" ] && umount $to_umount 341