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Up to [Qemu by Fabrice Bellard] / qemu / roms / ipxe / contrib / vm

Annotation of qemu/roms/ipxe/contrib/vm/cow, revision 1.1.1.1

1.1       root        1: #!/bin/sh
                      2: 
                      3: set -e
                      4: 
                      5: imgloop=
                      6: tmpfile=
                      7: tmploop=
                      8: dmname=
                      9: cowlink=
                     10: 
                     11: function cleanup () {
                     12:     set +e
                     13:     [ -n "$cowlink" ] && rm $cowlink
                     14:     [ -n "$dmname" ] && dmsetup remove $dmname
                     15:     [ -n "$tmploop" ] && losetup -d $tmploop
                     16:     [ -n "$tmpfile" ] && rm $tmpfile
                     17:     [ -n "$imgloop" ] && losetup -d $imgloop
                     18: }
                     19: 
                     20: trap cleanup EXIT
                     21: 
                     22: imgfile=$1 ; shift
                     23: command=$1 ; shift
                     24: if [ -z "$imgfile" -o -z "$command" ] ; then
                     25:     echo Syntax: $0 /path/to/image/file command [args..]
                     26:     exit 1
                     27: fi
                     28: 
                     29: # Set up image loop device
                     30: x=`losetup -f` ; losetup -r $x $imgfile ; imgloop=$x
                     31: 
                     32: # Create temporary file and set up temporary loop device
                     33: tmpfile=`mktemp $imgfile.XXXXXXXXXX`
                     34: truncate -r $imgfile $tmpfile
                     35: x=`losetup -f` ; losetup $x $tmpfile ; tmploop=$x
                     36: 
                     37: # Create snapshot device
                     38: imgsize=`blockdev --getsz $imgloop`
                     39: x=`basename $imgfile` ; echo 0 $imgsize snapshot $imgloop $tmploop N 16 | \
                     40:     dmsetup create $x ; dmname=$x
                     41: chown --reference=$imgfile /dev/mapper/$dmname
                     42: chmod --reference=$imgfile /dev/mapper/$dmname
                     43: 
                     44: # Create symlink
                     45: x=$imgfile.cow ; ln -s /dev/mapper/$dmname $x ; cowlink=$x
                     46: 
                     47: # Wait until killed
                     48: echo "Created $cowlink"
                     49: $command "$@" $cowlink

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