3 # Copyright (c) 1999 Matt Dillon
6 # Redistribution and use in source and binary forms, with or without
7 # modification, are permitted provided that the following conditions
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.
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
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!)
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
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:
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
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.
60 # The existence of a directory /conf/T/M causes this script to create a
61 # memory filesystem mounted as /M on the client.
63 # Some files in /conf have special meaning, namely:
66 # ----------------------------------------------------------------
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/
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
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".
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"
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/
100 # /conf/T/SUBDIR.remove
101 # The list of paths contained in the file are rm -rf'd
102 # relative to /SUBDIR.
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.
110 # You will almost universally want to create the following files under /conf
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
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
126 # plus, possibly, overrides for password files etc.
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.
132 # (end of documentation, now get to the real code)
134 dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
137 # log something on stdout if verbose.
138 o_verbose=0 # set to 1 or 2 if you want more debugging
140 [ ${o_verbose} -gt 0 ] && echo "*** $* ***"
141 [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo
146 # Routine to check for error
148 # checks error code and drops into shell on failure.
149 # if shell exits, terminates script as well as /etc/rc.
156 echo "$2 failed: dropping into /bin/sh"
163 # The list of filesystems to umount after the copy
166 handle_remount() { # $1 = mount point
167 local nfspt mountopts b
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}"
180 # Create a generic memory disk
183 /sbin/mdmfs -S -i 4096 -s $1 -M md $2
186 # Create the memory filesystem if it has not already been created
189 [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once
190 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
193 md_size=`eval echo \\$md_size_$1`
195 log create_md $1 with size $md_size
196 mount_md $md_size /$1
198 eval md_created_$1=created
205 # Figure out our interface and IP.
211 if [ ${dlv:=0} -ne 0 ] ; then
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=${2} ; shift
219 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
220 bootp_ipbca=$2; shift
224 if [ "${bootp_ifc}" != "" ] ; then
228 # Get the values passed with the T134 bootp cookie.
229 class="`/sbin/sysctl -qn kern.bootp_cookie`"
231 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}"
234 log Figure out our NFS root path
236 set -- `mount -t nfs`
237 while [ $# -ge 1 ] ; do
238 if [ "$2" = "on" -a "$3" = "/" ]; then
245 # The list of directories with template files
246 templates="base default"
247 if [ -n "${bootp_ipbca}" ]; then
248 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}"
250 if [ -n "${class}" ]; then
251 templates="${templates} ${class}"
253 if [ -n "${bootp_ipa}" ]; then
254 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}"
257 # If /conf/diskless_remount exists, remount all of /conf.
260 # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
261 # and /conf/${bootp_ipa}. For each subdirectory found within these
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.
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.
280 log "templates are ${templates}"
281 for i in ${templates} ; do
282 for j in /conf/$i/* ; do
283 [ -d $j ] || continue
285 # memory filesystem size specification
287 [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size`
289 # remount. Beware, the command is in the file itself!
290 if [ -f $j/remount ]; then
291 nfspt=`/bin/cat $j/remount`
293 chkerr $? "$nfspt $j"
294 to_umount="$j ${to_umount}" # XXX hope it is really a mount!
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
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/
311 for i in ${templates} ; do
312 for j in /conf/$i/* ; do
314 if [ -d $j -a ! -f $j.cpio.gz ]; then
319 for j in /conf/$i/*.cpio.gz ; do
320 subdir=${j%*.cpio.gz}
324 echo "Loading /$subdir from cpio archive $j"
325 (cd / ; /rescue/tar -xpf $j)
328 for j in /conf/$i/*.remove ; do
332 # doubly sure it is a memory disk before rm -rf'ing
334 (cd /$subdir; rm -rf `/bin/cat $j`)
339 # umount partitions used to fill the memory filesystems
340 [ -n "${to_umount}" ] && umount $to_umount