[linux-lvm] newer version of lvmcreateinitrd script

[Andreas Dilger]

Hello,
here is yet a newer version of the lvmcreateinitrd script.  I realized
after sending the old one that it is impossible to create > 8192 inodes
on an 8MB ext2 filesystem with 1k blocks, so this is now taken care of
by using a larger block size for the filesystem.

Cheers, Andreas
==========================================================================
#!/bin/sh
#
#  Copyright (C) 1997 - 2000  Heinz Mauelshagen, Sistina Software
# 
#  June 1999
#  December 1999
#  January 2000
#  January 2001
# 
#  LVM is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2, or (at your option)
#  any later version.
#  
#  LVM is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#  
#  You should have received a copy of the GNU General Public License
#  along with LVM; see the file COPYING.  If not, write to
#  the Free Software Foundation, 59 Temple Place - Suite 330,
#  Boston, MA 02111-1307, USA. 
# 

#
# Changelog
#
#   16/11/1999 - corrected -N type with mke2fs
#   19/12/1999 - use correct ramdisk size
#                strip shared library to save space
#   04/01/2000 - support /proc mount, because lvm_dir_cache now uses it
#   01/12/2001 - always create enough inodes in ramdisk for dev files
#   [AED]      - don't try to copy LVM module if LVM is compiled into kernel
#              - check all INITRDFILES for library dependencies
#              - make commands quiet and avoid redirecting errors to /dev/null
#              - use cleanup function for all errors, interrupts, normal exit
#              - allow creation of > 8192 inodes in case of large /dev
#

cmd=`basename $0`
VERSION=$1
[ -z "$VERSION" ] && VERSION=`uname -r`
DEVRAM=/tmp/initrd.$$
INITRD=/boot/initrd-lvm-$VERSION.gz
INITRDSIZE=8192
MODULES=/lib/modules/$VERSION
INITRDFILES="/sbin/modprobe /sbin/vgchange /sbin/vgscan /bin/bash /bin/mount /bin/umount /bin/sh /bin/rm /sbin/insmod $MODULES/modules.dep"
if [ -r $MODULES/kernel/drivers/md/lvm-mod.o ]; then
  INITRDFILES="$INITRDFILES $MODULES/kernel/drivers/md/lvm-mod.o"
elif [ -r $MODULES/block/lvm-mod.o ]; then
  INITRDFILES="$INITRDFILES $MODULES/block/lvm-mod.o"
elif [ -r $MODULES/block/lvm.o ]; then
  INITRDFILES="$INITRDFILES $MODULES/block/lvm.o"
fi

TMPMNT=/tmp/mnt.$$

cleanup () {
  [ "`mount | grep $DEVRAM`" ] && umount $DEVRAM
  [ -f $DEVRAM ] && rm $DEVRAM
  [ -d $TMPMNT ] && rmdir $TMPMNT
  exit $1
}

trap "
  echo -e 'Bye bye...\n'
  cleanup 1
" 1 2 3 15


create_fstab () {
   cat << FSTAB > $TMPMNT/etc/fstab
/dev/ram	/		ext2	defaults	0   0
proc		/proc		proc	defaults	0   0
FSTAB
   chmod 644 $TMPMNT/etc/fstab
}

create_linuxrc () {
   cat << LINUXRC > $TMPMNT/linuxrc
#!/bin/sh
/sbin/modprobe lvm-mod
/bin/mount /proc
/sbin/vgscan
/sbin/vgchange -a y
/bin/umount /proc
LINUXRC
   chmod 555 $TMPMNT/linuxrc
}

#
# Main
#
echo -e "\nLogical Volume Manager 0.9 by Heinz Mauelshagen  01/12/2001\n"
echo -e "$cmd -- create an LVM initial ram disk $INITRD\n"

# figure out which actual shared libraries we need in our initrd
echo "$cmd -- figuring out shared libraries"
SHLIBS=`ldd $INITRDFILES 2>/dev/null | awk '{if (/=>/) { print $3 }}' | sort -u`
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR figuring out needed shared libraries\n"
   exit 1
fi

#INITRDSIZE="`du -cLk /dev $SHLIBS $INITRDFILES | awk '/total/ { print $1 }'`"
echo "$cmd -- making loopback file ($INITRDSIZE kB)"
dd if=/dev/zero of=$DEVRAM count=$INITRDSIZE bs=1024 >/dev/null 2>&1
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR creating loopback file\n"
   cleanup 1
fi

# We can only have 8 * blocksize inodes per group, so for an 8MB filesystem
# (1 group) with > 8192 inodes, we need to use a bigger block size.  Yuk.
NUMINO="`find /dev /dev $SHLIBS $INITRDFILES | wc -w`"
NUMINO=`expr $NUMINO + 64`
if [ $NUMINO -gt `expr $INITRDSIZE \* 2` ]; then
   INODE_OPT="-b 4096 -N $NUMINO"
elif [ $NUMINO -gt $INITRDSIZE ]; then
   INODE_OPT="-b 2048 -N $NUMINO"
else
   INODE_OPT="-i `expr $INITRDSIZE \* 1024 / $NUMINO`"
fi
echo "$cmd -- making ram disk filesystem ($NUMINO inodes)"
mke2fs -q -F -m0 $INODE_OPT $DEVRAM $INITRDSIZE
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR making ram disk filesystem\n"
   cleanup 1
fi

mkdir $TMPMNT
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR making $TMPMNT\n"
   cleanup 1
fi

echo "$cmd -- mounting ram filesystem"
mount -oloop $DEVRAM $TMPMNT
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR mounting $DEVRAM on $TMPMNT\n"
   cleanup 1
fi

mkdir $TMPMNT/etc $TMPMNT/proc

#
# create new modules configuration to avoid kmod complaining
# about nonexsisting modules.
#
MODCONF=/etc/modules.conf
[ ! -r $MODCONF -a -r /etc/conf.modules ] && MODCONF=/etc/conf.modules
echo "$cmd -- creating new $MODCONF"
MAJ=0
while [ $MAJ -lt 256 ]; do
   echo "alias block-major-$MAJ	off"
   echo "alias char-major-$MAJ	off"
   MAJ=`expr $MAJ + 1`
done > $TMPMNT/$MODCONF

# to ensure, that modprobe doesn complain about timestamps
echo "$cmd -- creating new modules.dep"
depmod -a $VERSION
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR running depmod\n"
   cleanup 1
fi

# copy necessary files to ram disk
echo "$cmd -- copying files to ram disk"
find $INITRDFILES /dev|cpio -pdm --quiet $TMPMNT
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR cpio to ram disk\n"
   cleanup 1
fi

echo "$cmd -- copying shared libraries to ram disk"
for LIB in $SHLIBS; do
   cp $LIB $TMPMNT$LIB
   if [ $? -ne 0 ]; then
      echo -e "$cmd -- ERROR copying shared library $LIB to ram disk\n"
      cleanup 1
   fi
   strip $TMPMNT$LIB
   if [ $? -ne 0 ]; then
      echo -e "$cmd -- ERROR stripping shared library $LIB\n"
      cleanup 1
   fi
done

echo "$cmd -- creating new /linuxrc"
create_linuxrc
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR creating linuxrc\n"
   cleanup
   exit 1
fi

echo "$cmd -- creating new /etc/fstab"
create_fstab
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR creating /etc/fstab\n"
   cleanup 1
fi

echo "$cmd -- ummounting ram disk"
umount $DEVRAM
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR umounting $DEVRAM\n"
   cleanup 1
fi

echo "$cmd -- creating compressed initrd $INITRD"
dd if=$DEVRAM bs=1k count=$INITRDSIZE 2>/dev/null | gzip -9 > $INITRD
if [ $? -ne 0 ]; then
   echo -e "$cmd -- ERROR creating $INITRD\n"
   cleanup 1
fi

cleanup 0
-- 
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert