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/remount_optional
73 # If this file exists, then failure to execute the mount
74 # command contained in /conf/T/M/remount is non-fatal.
76 # /conf/T/M/diskless_remount
77 # The contents of the file points to an NFS filesystem,
78 # possibly followed by mount_nfs options. If the server name
79 # is omitted, the script will prepend the root path used when
80 # booting. E.g. if you booted from foo.com:/path/to/root,
81 # an entry for /conf/base/etc/diskless_remount could be any of
82 # foo.com:/path/to/root/etc
84 # Because mount_nfs understands ".." in paths, it is
85 # possible to mount from locations above the NFS root with
86 # paths such as "/../../etc".
89 # The contents of the file specifies the size of the memory
90 # filesystem to be created, in 512 byte blocks.
91 # The default size is 10240 blocks (5MB). E.g. if
92 # /conf/base/etc/md_size contains "30000" then a 15MB MFS
93 # will be created. In case of multiple entries for the same
94 # directory M, the last one in the scanning order is used.
95 # NOTE: If you only need to create a memory filesystem but not
96 # initialize it from a template, it is preferrable to specify
97 # it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0"
99 # /conf/T/SUBDIR.cpio.gz
100 # The file is cpio'd into /SUBDIR (and a memory filesystem is
101 # created for /SUBDIR if necessary). The presence of this file
102 # prevents the copy from /conf/T/SUBDIR/
104 # /conf/T/SUBDIR.remove
105 # The list of paths contained in the file are rm -rf'd
106 # relative to /SUBDIR.
108 # /conf/diskless_remount
109 # Similar to /conf/T/M/diskless_remount above, but allows
110 # all of /conf to be remounted. This can be used to allow
111 # multiple roots to share the same /conf.
114 # You will almost universally want to create the following files under /conf
117 # ---------------------------- ----------------------------------
118 # /conf/base/etc/md_size size of /etc filesystem
119 # /conf/base/etc/diskless_remount "/etc"
120 # /conf/default/etc/rc.conf generic diskless config parameters
121 # /conf/default/etc/fstab generic diskless fstab e.g. like this
123 # foo:/root_part / nfs ro 0 0
124 # foo:/usr_part /usr nfs ro 0 0
125 # foo:/home_part /home nfs rw 0 0
126 # md /tmp mfs -s=30m,rw 0 0
127 # md /var mfs -s=30m,rw 0 0
128 # proc /proc procfs rw 0 0
130 # plus, possibly, overrides for password files etc.
132 # NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g.
133 # as entries in the fstab as above.
134 # Those filesystems should not be specified in /conf.
136 # (end of documentation, now get to the real code)
138 dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
141 # log something on stdout if verbose.
142 o_verbose=0 # set to 1 or 2 if you want more debugging
144 [ ${o_verbose} -gt 0 ] && echo "*** $* ***"
145 [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo
150 # Routine to check for error
152 # checks error code and drops into shell on failure.
153 # if shell exits, terminates script as well as /etc/rc.
154 # if remount_optional exists under the mountpoint, skip this check.
157 lastitem () ( n=$(($# - 1)) ; shift $n ; echo $1 )
158 mountpoint="$(lastitem $2)"
159 [ -r $mountpoint/remount_optional ] && ( echo "$2 failed: ignoring due to remount_optional" ; return )
164 echo "$2 failed: dropping into /bin/sh"
171 # The list of filesystems to umount after the copy
174 handle_remount() { # $1 = mount point
175 local nfspt mountopts b
177 log handle_remount $1
178 [ -d $b -a -f $b/diskless_remount ] || return
179 read nfspt mountopts < $b/diskless_remount
180 log "nfspt ${nfspt} mountopts ${mountopts}"
181 # prepend the nfs root if not present
182 [ `expr "$nfspt" : '\(.\)'` = "/" ] && nfspt="${nfsroot}${nfspt}"
183 mount_nfs $mountopts $nfspt $b
184 chkerr $? "mount_nfs $nfspt $b"
185 to_umount="$b ${to_umount}"
188 # Create a generic memory disk
191 /sbin/mdmfs -S -i 4096 -s $1 -M md $2
194 # Create the memory filesystem if it has not already been created
197 [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once
198 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
201 md_size=`eval echo \\$md_size_$1`
203 log create_md $1 with size $md_size
204 mount_md $md_size /$1
206 eval md_created_$1=created
213 # Figure out our interface and IP.
219 if [ ${dlv:=0} -ne 0 ] ; then
221 for i in ${iflist} ; do
222 set -- `ifconfig ${i}`
223 while [ $# -ge 1 ] ; do
224 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then
225 bootp_ifc=${i} ; bootp_ipa=${2} ; shift
227 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
228 bootp_ipbca=$2; shift
232 if [ "${bootp_ifc}" != "" ] ; then
236 # Get the values passed with the T134 bootp cookie.
237 class="`/sbin/sysctl -qn kern.bootp_cookie`"
239 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}"
242 log Figure out our NFS root path
244 set -- `mount -t nfs`
245 while [ $# -ge 1 ] ; do
246 if [ "$2" = "on" -a "$3" = "/" ]; then
253 # The list of directories with template files
254 templates="base default"
255 if [ -n "${bootp_ipbca}" ]; then
256 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}"
258 if [ -n "${class}" ]; then
259 templates="${templates} ${class}"
261 if [ -n "${bootp_ipa}" ]; then
262 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}"
265 # If /conf/diskless_remount exists, remount all of /conf.
268 # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
269 # and /conf/${bootp_ipa}. For each subdirectory found within these
272 # - calculate memory filesystem sizes. If the subdirectory (prior to
273 # NFS remounting) contains the file 'md_size', the contents specified
274 # in 512 byte sectors will be used to size the memory filesystem. Otherwise
275 # 8192 sectors (4MB) is used.
277 # - handle NFS remounts. If the subdirectory contains the file
278 # diskless_remount, the contents of the file is NFS mounted over
279 # the directory. For example /conf/base/etc/diskless_remount
280 # might contain 'myserver:/etc'. NFS remounts allow you to avoid
281 # having to dup your system directories in /conf. Your server must
282 # be sure to export those filesystems -alldirs, however.
283 # If the diskless_remount file contains a string beginning with a
284 # '/' it is assumed that the local nfsroot should be prepended to
285 # it before attemping to the remount. This allows the root to be
286 # relocated without needing to change the remount files.
288 log "templates are ${templates}"
289 for i in ${templates} ; do
290 for j in /conf/$i/* ; do
291 [ -d $j ] || continue
293 # memory filesystem size specification
295 [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size`
297 # remount. Beware, the command is in the file itself!
298 if [ -f $j/remount ]; then
299 nfspt=`/bin/cat $j/remount`
301 chkerr $? "$nfspt $j"
302 to_umount="$j ${to_umount}" # XXX hope it is really a mount!
310 # - Create all required MFS filesystems and populate them from
311 # our templates. Support both a direct template and a dir.cpio.gz
312 # archive. Support dir.remove files containing a list of relative
315 # The dir.cpio.gz form is there to make the copy process more efficient,
316 # so if the cpio archive is present, it prevents the files from dir/
319 for i in ${templates} ; do
320 for j in /conf/$i/* ; do
322 if [ -d $j -a ! -f $j.cpio.gz ]; then
327 for j in /conf/$i/*.cpio.gz ; do
328 subdir=${j%*.cpio.gz}
332 echo "Loading /$subdir from cpio archive $j"
333 (cd / ; /rescue/tar -xpf $j)
336 for j in /conf/$i/*.remove ; do
340 # doubly sure it is a memory disk before rm -rf'ing
342 (cd /$subdir; rm -rf `/bin/cat $j`)
347 # umount partitions used to fill the memory filesystems
348 [ -n "${to_umount}" ] && umount $to_umount