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 typically 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 successive 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 manageable 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 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/remount_subdir
77 # If this file exists, then the behaviour of /conf/T/M/remount
79 # 1. /conf/T/M/remount is invoked to mount the root of the
80 # filesystem where the configuration data exists on a
81 # temporary mountpoint.
82 # 2. /conf/T/M/remount_subdir is then invoked to mount a
83 # *subdirectory* of the filesystem mounted by
84 # /conf/T/M/remount on /conf/T/M/.
86 # /conf/T/M/diskless_remount
87 # The contents of the file points to an NFS filesystem,
88 # possibly followed by mount_nfs options. If the server name
89 # is omitted, the script will prepend the root path used when
90 # booting. E.g. if you booted from foo.com:/path/to/root,
91 # an entry for /conf/base/etc/diskless_remount could be any of
92 # foo.com:/path/to/root/etc
94 # Because mount_nfs understands ".." in paths, it is
95 # possible to mount from locations above the NFS root with
96 # paths such as "/../../etc".
99 # The contents of the file specifies the size of the memory
100 # filesystem to be created, in 512 byte blocks.
101 # The default size is 10240 blocks (5MB). E.g. if
102 # /conf/base/etc/md_size contains "30000" then a 15MB MFS
103 # will be created. In case of multiple entries for the same
104 # directory M, the last one in the scanning order is used.
105 # NOTE: If you only need to create a memory filesystem but not
106 # initialize it from a template, it is preferable to specify
107 # it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0"
109 # /conf/T/SUBDIR.cpio.gz
110 # The file is cpio'd into /SUBDIR (and a memory filesystem is
111 # created for /SUBDIR if necessary). The presence of this file
112 # prevents the copy from /conf/T/SUBDIR/
115 # This is alternative to SUBDIR.cpio.gz and remount.
116 # Similar to remount case, a memory filesystem is created
117 # for /M and initialized from a template but no mounting
118 # performed. Instead, this file is run passing /M as single
119 # argument. It is expected to extract template override to /M
120 # using auxiliary storage found in some embedded systems
121 # having NVRAM too small to hold mountable file system.
123 # /conf/T/SUBDIR.remove
124 # The list of paths contained in the file are rm -rf'd
125 # relative to /SUBDIR.
127 # /conf/diskless_remount
128 # Similar to /conf/T/M/diskless_remount above, but allows
129 # all of /conf to be remounted. This can be used to allow
130 # multiple roots to share the same /conf.
133 # You will almost universally want to create the following files under /conf
136 # ---------------------------- ----------------------------------
137 # /conf/base/etc/md_size size of /etc filesystem
138 # /conf/base/etc/diskless_remount "/etc"
139 # /conf/default/etc/rc.conf generic diskless config parameters
140 # /conf/default/etc/fstab generic diskless fstab e.g. like this
142 # foo:/root_part / nfs ro 0 0
143 # foo:/usr_part /usr nfs ro 0 0
144 # foo:/home_part /home nfs rw 0 0
145 # md /tmp mfs -s=30m,rw 0 0
146 # md /var mfs -s=30m,rw 0 0
147 # proc /proc procfs rw 0 0
149 # plus, possibly, overrides for password files etc.
151 # NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g.
152 # as entries in the fstab as above.
153 # Those filesystems should not be specified in /conf.
155 # (end of documentation, now get to the real code)
157 dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
160 # log something on stdout if verbose.
161 o_verbose=0 # set to 1 or 2 if you want more debugging
163 [ ${o_verbose} -gt 0 ] && echo "*** $* ***"
164 [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo
169 # Routine to check for error
171 # checks error code and drops into shell on failure.
172 # if shell exits, terminates script as well as /etc/rc.
173 # if remount_optional exists under the mountpoint, skip this check.
176 lastitem () ( n=$(($# - 1)) ; shift $n ; echo $1 )
177 mountpoint="$(lastitem $2)"
178 [ -r $mountpoint/remount_optional ] && ( echo "$2 failed: ignoring due to remount_optional" ; return )
183 echo "$2 failed: dropping into /bin/sh"
190 # The list of filesystems to umount after the copy
193 handle_remount() { # $1 = mount point
194 local nfspt mountopts b
196 log handle_remount $1
197 [ -d $b -a -f $b/diskless_remount ] || return
198 read nfspt mountopts < $b/diskless_remount
199 log "nfspt ${nfspt} mountopts ${mountopts}"
200 # prepend the nfs root if not present
201 [ `expr "$nfspt" : '\(.\)'` = "/" ] && nfspt="${nfsroot}${nfspt}"
202 mount_nfs $mountopts $nfspt $b
203 chkerr $? "mount_nfs $nfspt $b"
204 to_umount="$b ${to_umount}"
207 # Create a generic memory disk.
208 # The 'auto' parameter will attempt to use tmpfs(5), falls back to md(4).
209 # $1 is size in 512-byte sectors, $2 is the mount point.
211 if [ ${o_verbose} -gt 0 ] ; then
212 /sbin/mdmfs -XL -s $1 auto $2
214 /sbin/mdmfs -s $1 auto $2
218 # Create the memory filesystem if it has not already been created
221 [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once
222 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
225 md_size=`eval echo \\$md_size_$1`
227 log create_md $1 with size $md_size
228 mount_md $md_size /$1
230 eval md_created_$1=created
237 # Figure out our interface and IP.
243 if [ ${dlv:=0} -ne 0 ] ; then
245 for i in ${iflist} ; do
246 set -- `ifconfig ${i}`
247 while [ $# -ge 1 ] ; do
248 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then
249 bootp_ifc=${i} ; bootp_ipa=${2} ; shift
251 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
252 bootp_ipbca=$2; shift
256 if [ "${bootp_ifc}" != "" ] ; then
260 # Get the values passed with the T134 bootp cookie.
261 class="`/sbin/sysctl -qn kern.bootp_cookie`"
263 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}"
266 log Figure out our NFS root path
268 set -- `mount -t nfs`
269 while [ $# -ge 1 ] ; do
270 if [ "$2" = "on" -a "$3" = "/" ]; then
277 # The list of directories with template files
278 templates="base default"
279 if [ -n "${bootp_ipbca}" ]; then
280 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}"
282 if [ -n "${class}" ]; then
283 templates="${templates} ${class}"
285 if [ -n "${bootp_ipa}" ]; then
286 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}"
289 # If /conf/diskless_remount exists, remount all of /conf.
292 # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
293 # and /conf/${bootp_ipa}. For each subdirectory found within these
296 # - calculate memory filesystem sizes. If the subdirectory (prior to
297 # NFS remounting) contains the file 'md_size', the contents specified
298 # in 512 byte sectors will be used to size the memory filesystem. Otherwise
299 # 8192 sectors (4MB) is used.
301 # - handle NFS remounts. If the subdirectory contains the file
302 # diskless_remount, the contents of the file is NFS mounted over
303 # the directory. For example /conf/base/etc/diskless_remount
304 # might contain 'myserver:/etc'. NFS remounts allow you to avoid
305 # having to dup your system directories in /conf. Your server must
306 # be sure to export those filesystems -alldirs, however.
307 # If the diskless_remount file contains a string beginning with a
308 # '/' it is assumed that the local nfsroot should be prepended to
309 # it before attemping to the remount. This allows the root to be
310 # relocated without needing to change the remount files.
312 log "templates are ${templates}"
313 for i in ${templates} ; do
314 for j in /conf/$i/* ; do
315 [ -d $j ] || continue
317 # memory filesystem size specification
319 [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size`
321 # remount. Beware, the command is in the file itself!
322 if [ -f $j/remount ]; then
323 if [ -f $j/remount_subdir ]; then
324 k="/conf.tmp/$i/$subdir"
325 [ -d $k ] || continue
327 # Mount the filesystem root where the config data is
328 # on the temporary mount point.
329 nfspt=`/bin/cat $j/remount`
331 chkerr $? "$nfspt $k"
333 # Now use a nullfs mount to get the data where we
334 # really want to see it.
335 remount_subdir=`/bin/cat $j/remount_subdir`
336 remount_subdir_cmd="mount -t nullfs $k/$remount_subdir"
338 $remount_subdir_cmd $j
339 chkerr $? "$remount_subdir_cmd $j"
341 # XXX check order -- we must force $k to be unmounted
342 # after j, as j depends on k.
343 to_umount="$j $k ${to_umount}"
345 nfspt=`/bin/cat $j/remount`
347 chkerr $? "$nfspt $j"
348 to_umount="$j ${to_umount}" # XXX hope it is really a mount!
357 # - Create all required MFS filesystems and populate them from
358 # our templates. Support both a direct template and a dir.cpio.gz
359 # archive. Support for auxiliary NVRAM. Support dir.remove files containing
360 # a list of relative paths to remove.
362 # The dir.cpio.gz form is there to make the copy process more efficient,
363 # so if the cpio archive is present, it prevents the files from dir/
366 for i in ${templates} ; do
367 for j in /conf/$i/* ; do
369 if [ -d $j -a ! -f $j.cpio.gz ]; then
374 for j in /conf/$i/*.cpio.gz ; do
375 subdir=${j%*.cpio.gz}
379 echo "Loading /$subdir from cpio archive $j"
380 (cd / ; /rescue/tar -xpf $j)
383 for j in /conf/$i/*/extract ; do
385 subdir=${j%*/extract}
388 echo "Loading /$subdir using auxiliary command $j"
392 for j in /conf/$i/*.remove ; do
396 # doubly sure it is a memory disk before rm -rf'ing
398 (cd /$subdir; rm -rf `/bin/cat $j`)
403 # umount partitions used to fill the memory filesystems
404 [ -n "${to_umount}" ] && umount $to_umount