mdw@git.distorted.org.uk Git - profile/blob - bin/check-blkdev-size

   1 #! /bin/bash
   2
   3 set -e -o pipefail
   4 prog=${0##*/}
   5
   6 case $# in 1) ;; *) echo >&2 "usage: $prog DEV"; exit 127 ;; esac
   7 dev=$1
   8
   9 typeset -i sz; sz=$(blockdev --getsize64 "$dev")
  10 k=$(gorp -fhex 256)
  11
  12 ## Figure out a useful block size.
  13 typeset -i bsz=1 nb=$sz
  14 for i in 2 3 5 7; do
  15   while :; do
  16     case $((nb%i)) in
  17       0) bsz=$((bsz*i)) nb=$((nb/i)) ;;
  18       *) break ;;
  19     esac
  20     if (( bsz >= 65536 )); then break 2; fi
  21   done
  22 done
  23 echo >&2 "$prog: using $nb blocks of size $bsz"
  24
  25 ## Write the initial stream.
  26 echo >&2 "$prog: writing pseudorandom pattern..."
  27 rspit salsa20/8 -H$k -z$sz -pT | \
  28   dd status=none iflag=fullblock oflag=direct bs=$bsz count=$nb of="$dev"
  29 echo >&2 "$prog: writing pseudorandom pattern... done"
  30
  31 ## Read the stream back, and check against the reference.
  32 echo >&2 "$prog: checking pseudorandom pattern..."
  33 cmp <(rspit salsa20/8 -H$k -z$sz -pT) \
  34     <(dd status=none iflag=direct bs=$bsz count=$nb if="$dev")
  35 echo >&2 "$prog: checking pseudorandom pattern... done"
  36 echo >&2 "$prog: all ok"