#!/bin/bash
# Script to rescan SCSI bus, using the scsi add-single-device mechanism.
# (c) 1998--2010 Kurt Garloff <kurt@garloff.de>, GNU GPL v2 or v3
# (c) 2006--2018 Hannes Reinecke, GNU GPL v2 or later
# $Id: rescan-scsi-bus.sh,v 1.57 2012/03/31 14:08:48 garloff Exp $

VERSION="20180615"
SCAN_WILD_CARD=4294967295

setcolor ()
{
  red="\e[0;31m"
  green="\e[0;32m"
  yellow="\e[0;33m"
  bold="\e[0;1m"
  norm="\e[0;0m"
}

unsetcolor ()
{
  red=""; green=""
  yellow=""; norm=""
}

echo_debug()
{
  if [ "$debug" -eq 1 ] ; then
     echo "$1"
  fi
}

# Output some text and return cursor to previous position
# (only works for simple strings)
# Stores length of string in LN and returns it
print_and_scroll_back ()
{
  STRG="$1"
  LN=${#STRG}
  BK=""
  declare -i cntr=0
  while [ $cntr -lt "$LN" ] ; do BK="$BK\e[D"; let cntr+=1; done
  echo -en "$STRG$BK"
  return "$LN"
}

# Overwrite a text of length $LN with whitespace
white_out ()
{
  BK=""; WH=""
  declare -i cntr=0
  while [ $cntr -lt "$LN" ] ; do BK="$BK\e[D"; WH="$WH "; let cntr+=1; done
  echo -en "$WH$BK"
}

# Return hosts. sysfs must be mounted
findhosts_26 ()
{
  hosts=
  for hostdir in /sys/class/scsi_host/host* ; do
    [ -e "$hostdir" ] || continue
    hostno=${hostdir#/sys/class/scsi_host/host}
    if [ -f "$hostdir/isp_name" ] ; then
      hostname="qla2xxx"
    elif [ -f "$hostdir/lpfc_drvr_version" ] ; then
      hostname="lpfc"
    else
      hostname=$(cat "$hostdir/proc_name")
    fi
    hosts="$hosts $hostno"
    echo_debug "Host adapter $hostno ($hostname) found."
  done
  if [ -z "$hosts" ] ; then
    echo "No SCSI host adapters found in sysfs"
    exit 1;
  fi
  # Not necessary just use double quotes around variable to preserve new lines
  #hosts=$(echo $hosts | tr ' ' '\n')
}

# Return hosts. /proc/scsi/HOSTADAPTER/? must exist
findhosts ()
{
  hosts=
  for driverdir in /proc/scsi/*; do
    driver=${driverdir#/proc/scsi/}
    if [ "$driver" = scsi ] || [ "$driver" = sg ] || [ "$driver" = dummy ] || [ "$driver" = device_info  ] ; then continue; fi
    for hostdir in $driverdir/*; do
      name=${hostdir#/proc/scsi/*/}
      if [ "$name" = add_map ] || [ "$name" = map ]  || [ "$name" = mod_parm ] ; then continue; fi
      num=$name
      driverinfo=$driver
      if [ -r "$hostdir/status" ] ; then
        num=$(printf '%d\n' "$(sed -n 's/SCSI host number://p' "$hostdir/status")")
        driverinfo="$driver:$name"
      fi
      hosts="$hosts $num"
      echo "Host adapter $num ($driverinfo) found."
    done
  done
}

printtype ()
{
  local type=$1

  case "$type" in
    0) echo "Direct-Access" ;;
    1) echo "Sequential-Access" ;;
    2) echo "Printer" ;;
    3) echo "Processor" ;;
    4) echo "WORM" ;;
    5) echo "CD-ROM" ;;
    6) echo "Scanner" ;;
    7) echo "Optical-Device" ;;
    8) echo "Medium-Changer" ;;
    9) echo "Communications" ;;
    10) echo "Unknown" ;;
    11) echo "Unknown" ;;
    12) echo "RAID" ;;
    13) echo "Enclosure" ;;
    14) echo "Direct-Access-RBC" ;;
    *) echo "Unknown" ;;
  esac
}

print02i()
{
    if [ "$1" = "*" ] ; then
        echo "00"
    else
        printf "%02i" "$1"
    fi
}

# Get /proc/scsi/scsi info for device $host:$channel:$id:$lun
# Optional parameter: Number of lines after first (default = 2),
# result in SCSISTR, return code 1 means empty.
procscsiscsi ()
{
  if [ -z "$1" ] ; then
    LN=2
  else
    LN=$1
  fi
  CHANNEL=$(print02i "$channel")
  ID=$(print02i "$id")
  LUN=$(print02i "$lun")
  if [ -d /sys/class/scsi_device ]; then
    SCSIPATH="/sys/class/scsi_device/${host}:${channel}:${id}:${lun}"
    if [ -d  "$SCSIPATH" ] ; then
      SCSISTR="Host: scsi${host} Channel: $CHANNEL Id: $ID Lun: $LUN"
      if [ "$LN" -gt 0 ] ; then
        IVEND=$(cat "${SCSIPATH}/device/vendor")
        IPROD=$(cat "${SCSIPATH}/device/model")
        IPREV=$(cat "${SCSIPATH}/device/rev")
        SCSIDEV=$(printf '  Vendor: %-08s Model: %-16s Rev: %-4s' "$IVEND" "$IPROD" "$IPREV")
        SCSISTR="$SCSISTR
$SCSIDEV"
      fi
      if [ "$LN" -gt 1 ] ; then
        ILVL=$(cat "${SCSIPATH}/device/scsi_level")
        type=$(cat "${SCSIPATH}/device/type")
        ITYPE=$(printtype "$type")
        SCSITMP=$(printf '  Type:   %-17s                ANSI SCSI revision: %02d' "$ITYPE" "$((ILVL - 1))")
        SCSISTR="$SCSISTR
$SCSITMP"
      fi
    else
      return 1
    fi
  else
    grepstr="scsi$host Channel: $CHANNEL Id: $ID Lun: $LUN"
    SCSISTR=$(grep -A "$LN" -e "$grepstr" /proc/scsi/scsi)
  fi
  if [ -z "$SCSISTR" ] ; then
    return 1
  else
    return 0
  fi
}

# Find sg device with 2.6 sysfs support
sgdevice26 ()
{
  local gendev

  gendev=/sys/class/scsi_device/${host}:${channel}:${id}:${lun}/device/generic
  if [ -e "$gendev" ] ; then
    SGDEV=$(basename "$(readlink "$gendev")")
  else
    for SGDEV in /sys/class/scsi_generic/sg*; do
      DEV=$(readlink "$SGDEV/device")
      if [ "${DEV##*/}" = "$host:$channel:$id:$lun" ] ; then
        SGDEV=$(basename "$SGDEV"); return
      fi
    done
    SGDEV=""
  fi
}

# Find sg device with 2.4 report-devs extensions
sgdevice24 ()
{
  if procscsiscsi 3; then
    SGDEV=$(echo "$SCSISTR" | grep 'Attached drivers:' | sed 's/^ *Attached drivers: \(sg[0-9]*\).*/\1/')
  fi
}

# Find sg device that belongs to SCSI device $host $channel $id $lun
# and return in SGDEV
sgdevice ()
{
  SGDEV=
  if [ -d /sys/class/scsi_device ] ; then
    sgdevice26
  else
    DRV=$(grep 'Attached drivers:' /proc/scsi/scsi 2>/dev/null)
    repdevstat=$((1-$?))
    if [ $repdevstat = 0 ]; then
      echo "scsi report-devs 1" >/proc/scsi/scsi
      DRV=$(grep 'Attached drivers:' /proc/scsi/scsi 2>/dev/null)
      [ $? -eq 1 ] && return
    fi
    if ! echo "$DRV" | grep -q 'drivers: sg'; then
      modprobe sg
    fi
    sgdevice24
    if [ $repdevstat = 0 ]; then
      echo "scsi report-devs 0" >/proc/scsi/scsi
    fi
  fi
}

# Whether or not the RMB (removable) bit has been set in the INQUIRY response.
# Uses ${host}, ${channel}, ${id} and ${lun}. Assumes that sg_device() has
# already been called. How to test this function: copy/paste this function
# in a shell and run
# (cd /sys/class/scsi_device && for d in *; do set ${d//:/ }; echo -n "$d $(</sys/class/scsi_device/${d}/device/block/*/removable) <> "; SGDEV=bsg/$d host=$1 channel=$2 id=$3 lun=$4 is_removable; done)
is_removable ()
{
  local b p

  p=/sys/class/scsi_device/${host}:${channel}:${id}:${lun}/device/inquiry
  # Extract the second byte of the INQUIRY response and check bit 7 (mask 0x80).
  b=$(hexdump -n1 -e '/1 "%02X"' "$p" 2>/dev/null)
  if [ -n "$b" ]; then
    echo $(((0x$b & 0x80) != 0))
  else
    sg_inq /dev/$SGDEV 2>/dev/null | sed -n 's/^.*RMB=\([0-9]*\).*$/\1/p'
  fi
}

# Test if SCSI device is still responding to commands
# Return values:
#   0 device is present
#   1 device has changed
#   2 device has been removed
testonline ()
{
  local ctr RC RMB

  : testonline
  ctr=0
  RC=0
  # Set default values
  IPTYPE=31
  IPQUAL=3
  [ ! -x /usr/bin/sg_turs ] && return 0
  sgdevice
  [ -z "$SGDEV" ] && return 0
  sg_turs /dev/$SGDEV >/dev/null 2>&1
  RC=$?

  # Handle in progress of becoming ready and unit attention
  while [ $RC = 2 -o $RC = 6 ] && [ $ctr -le 30 ] ; do
    if [ $RC = 2 ] && [ "$RMB" != "1" ] ; then
      echo -n "."
      let LN+=1
      sleep 1
    else
      sleep 0.02
    fi
    let ctr+=1
    sg_turs /dev/$SGDEV >/dev/null 2>&1
    RC=$?
    # Check for removable device; TEST UNIT READY obviously will
    # fail for a removable device with no medium
    RMB=$(is_removable)
    print_and_scroll_back "$host:$channel:$id:$lun $SGDEV ($RMB) "
    [ $RC = 2 ] && [ "$RMB" = "1" ] && break
  done
  if [ $ctr != 0 ] ; then
    white_out
  fi
  # echo -e "\e[A\e[A\e[A${yellow}Test existence of $SGDEV = $RC ${norm} \n\n\n"
  [ $RC = 1 ] && return $RC
  # Reset RC (might be !=0 for passive paths)
  RC=0
  # OK, device online, compare INQUIRY string
  INQ=$(sg_inq "$sg_len_arg" /dev/$SGDEV 2>/dev/null)
  if [ -z "$INQ" ] ; then
    echo -e "\e[A\e[A\e[A\e[A${red}$SGDEV changed: ${bold}INQUIRY failed${norm}    \n\n\n"
    return 2
  fi
  IVEND=$(echo "$INQ" | grep 'Vendor identification:' | sed 's/^[^:]*: \(.*\)$/\1/')
  IPROD=$(echo "$INQ" | grep 'Product identification:' | sed 's/^[^:]*: \(.*\)$/\1/')
  IPREV=$(echo "$INQ" | grep 'Product revision level:' | sed 's/^[^:]*: \(.*\)$/\1/')
  STR=$(printf "  Vendor: %-08s Model: %-16s Rev: %-4s" "$IVEND" "$IPROD" "$IPREV")
  IPTYPE=$(echo "$INQ" | sed -n 's/.* Device_type=\([0-9]*\) .*/\1/p')
  if [ -z "$IPTYPE" ]; then
    IPTYPE=$(echo "$INQ" | sed -n 's/.* PDT=\([0-9]*\) .*/\1/p')
  fi
  IPQUAL=$(echo "$INQ" | sed -n 's/ *PQual=\([0-9]*\)  Device.*/\1/p')
  if [ -z "$IPQUAL" ] ; then
    IPQUAL=$(echo "$INQ" | sed -n 's/ *PQual=\([0-9]*\)  PDT.*/\1/p')
  fi
  if [ "$IPQUAL" != 0 ] ; then
    [ -z "$IPQUAL" ] && IPQUAL=3
    [ -z "$IPTYPE" ] && IPTYPE=31
    echo -e "\e[A\e[A\e[A\e[A${red}$SGDEV changed: ${bold}LU not available (PQual $IPQUAL)${norm}    \n\n\n"
    return 2
  fi

  TYPE=$(printtype $IPTYPE)
  if ! procscsiscsi ; then
    echo -e "\e[A\e[A\e[A\e[A${red}$SGDEV removed.\n\n\n"
    return 2
  fi
  TMPSTR=$(echo "$SCSISTR" | grep 'Vendor:')
  if [ "$ignore_rev" -eq 0 ] ; then
      if [ "$TMPSTR" != "$STR" ]; then
        echo -e "\e[A\e[A\e[A\e[A${red}$SGDEV changed: ${bold}\nfrom:${SCSISTR#* } \nto: $STR ${norm} \n\n\n"
        return 1
      fi
  else
      # Ignore disk revision change
      local old_str_no_rev=
      local new_str_no_rev=

      old_str_no_rev=${TMPSTR%Rev:*}
      new_str_no_rev=${STR%Rev:*}
      if [ "$old_str_no_rev" != "$new_str_no_rev" ]; then
        echo -e "\e[A\e[A\e[A\e[A${red}$SGDEV changed: ${bold}\nfrom:${SCSISTR#* } \nto: $STR ${norm} \n\n\n"
        return 1
      fi
  fi
  TMPSTR=$(echo "$SCSISTR" | sed -n 's/.*Type: *\(.*\) *ANSI.*/\1/p' | sed 's/ *$//g')
  if [ "$TMPSTR" != "$TYPE" ] ; then
    echo -e "\e[A\e[A\e[A\e[A${red}$SGDEV changed: ${bold}\nfrom:${TMPSTR} \nto: $TYPE ${norm} \n\n\n"
    return 1
  fi
  return $RC
}

# Test if SCSI device $host $channel $id $lun exists
# Outputs description from /proc/scsi/scsi (unless arg passed)
# Returns SCSISTR (empty if no dev)
testexist ()
{
  : testexist
  SCSISTR=
  if procscsiscsi && [ -z "$1" ] ; then
    echo "$SCSISTR" | head -n1
    echo "$SCSISTR" | tail -n2 | pr -o4 -l1
  fi
}

# Returns the list of existing channels per host
chanlist ()
{
  local hcil
  local cil
  local chan
  local tmpchan

  for dev in /sys/class/scsi_device/${host}:* ; do
    [ -d "$dev" ] || continue;
    hcil=${dev##*/}
    cil=${hcil#*:}
    chan=${cil%%:*}
    for tmpchan in $channelsearch ; do
      if [ "$chan" -eq "$tmpchan" ] ; then
        chan=
      fi
    done
    if [ -n "$chan" ] ; then
      channelsearch="$channelsearch $chan"
    fi
  done
  if [ -z "$channelsearch" ] ; then
    channelsearch="0"
  fi
}

# Returns the list of existing targets per host
idlist ()
{
  local tmpid
  local newid
  local oldid

  oldlist=$(find /sys/class/scsi_device -name "${host}:${channel}:*" -printf "%f\n")
  # Rescan LUN 0 to check if we found new targets
  echo "${channel} - -" > "/sys/class/scsi_host/host${host}/scan"
  newlist=$(find /sys/class/scsi_device -name "${host}:${channel}:*" -printf "%f\n")
  for newid in $newlist ; do
    oldid=$newid
    for tmpid in $oldlist ; do
      if [ "$newid" = "$tmpid" ] ; then
        oldid=
        break
      fi
    done
    if [ -n "$oldid" ] ; then
      if [ -d /sys/class/scsi_device/$oldid ] ; then
	hcil=${oldid}
        printf "\r${green}NEW: %s" "$norm"
        testexist
        if [ "$SCSISTR" ] ; then
          incrfound "$hcil"
        fi
      fi
    fi
  done
  idsearch=$(find /sys/bus/scsi/devices -name "target${host}:${channel}:*" -printf "%f\n" | cut -f 3 -d :)
}

# Returns the list of existing LUNs from device $host $channel $id $lun
# and returns list to stdout
getluns()
{
  sgdevice
  [ -z "$SGDEV" ] && return 1
  if [ ! -x /usr/bin/sg_luns ] ; then
    echo 0
    return 1
  fi
  LLUN=$(sg_luns /dev/$SGDEV 2>/dev/null | sed -n 's/    \(.*\)/\1/p')
  # Added -z $LLUN condition because $? gets the RC from sed, not sg_luns
  if [ $? -ne 0 ] || [ -z "$LLUN" ] ; then
    echo 0
    return 1
  fi
  for lun in $LLUN ; do
      # Swap LUN number
      l0=0x$lun
      l1=$(( (l0 >> 48) & 0xffff ))
      l2=$(( (l0 >> 32) & 0xffff ))
      l3=$(( (l0 >> 16) & 0xffff ))
      l4=$(( l0 & 0xffff ))
      l0=$(( ( ( (l4 * 0xffff) + l3 ) * 0xffff + l2 ) * 0xffff + l1 ))
      printf "%u\n" $l0
  done
  return 0
}

# Wait for udev to settle (create device nodes etc.)
udevadm_settle()
{
  local tmo=60
  if [ -x /bin/udevadm ] ; then
    print_and_scroll_back " Calling udevadm settle (can take a while) "
    # Loop for up to 60 seconds if sd devices still are settling..
    # This allows us to continue if udev events are stuck on multipaths in recovery mode
    while [ $tmo -gt 0 ] ; do
      if ! /bin/udevadm settle --timeout=1 | egrep -q sd[a-z]+ ; then
        break;
      fi
      let tmo=$tmo-1
    done
    white_out
  elif [ -x /sbin/udevsettle ] ; then
    print_and_scroll_back " Calling udevsettle (can take a while) "
    /sbin/udevsettle
    white_out
  else
    sleep 0.02
  fi
}

# Perform scan on a single lun $host $channel $id $lun
dolunscan()
{
  local remappedlun0=
  local devpath
  SCSISTR=
  devnr="$host $channel $id $lun"
  echo -e " Scanning for device $devnr ... "
  printf "${yellow}OLD: %s" "$norm"
  testexist
  # Device exists: Test whether it's still online
  # (testonline returns 2 if it's gone and 1 if it has changed)
  devpath="/sys/class/scsi_device/${host}:${channel}:${id}:${lun}/device"
  if [ "$SCSISTR" ] ; then
    testonline
    RC=$?
    # Well known lun transition case. Only for Direct-Access devs (type 0)
    # If block directory exists && and PQUAL != 0, we unmapped lun0 and just have a well-known lun
    # If block directory doesn't exist && PQUAL == 0, we mapped a real lun0
    if [ "$lun" -eq 0 ] && [ $IPTYPE -eq 0 ] ; then
      if [ $RC = 2 ] ; then
        if [ -e "$devpath" ] ; then
          if [ -d "$devpath/block" ] ; then
            remappedlun0=2  # Transition from real lun 0 to well-known
          else
            RC=0   # Set this so the system leaves the existing well known lun alone. This is a lun 0 with no block directory
          fi
        fi
      elif [ $RC = 0 ] && [ $IPTYPE -eq 0 ] ; then
        if [ -e "$devpath" ] ; then
          if [ ! -d "$devpath/block" ] ; then
            remappedlun0=1  # Transition from well-known to real lun 0
          fi
        fi
      fi
    fi
  fi

  # Special case: lun 0 just got added (for reportlunscan),
  # so make sure we correctly treat it as new
  if [ "$lun" = "0" ] && [ "$1" = "1" ] && [ -z "$remappedlun0" ] ; then
    SCSISTR=""
    printf "\r\e[A\e[A\e[A"
  fi

  : f "$remove" s $SCSISTR
  if [ "$remove" ] && [ "$SCSISTR" -o "$remappedlun0" = "1" ] ; then
    if [ $RC != 0 ] || [ ! -z "$forceremove" ] || [ -n "$remappedlun0" ] ; then
      if [ "$remappedlun0" != "1" ] ; then
        echo -en "\r\e[A\e[A\e[A${red}REM: "
        echo "$SCSISTR" | head -n1
        echo -e "${norm}\e[B\e[B"
      fi
      if [ -e "$devpath" ] ; then
        # have to preemptively do this so we can figure out the mpath device
        # Don't do this if we're deleting a well known lun to replace it
        if [ "$remappedlun0" != "1" ] ; then
          incrrmvd "$host:$channel:$id:$lun"
        fi
        echo 1 > "$devpath/delete"
        sleep 0.02
      else
        echo "scsi remove-single-device $devnr" > /proc/scsi/scsi
        if [ $RC -eq 1 ] || [ "$lun" -eq 0 ] ; then
          # Try readding, should fail if device is gone
          echo "scsi add-single-device $devnr" > /proc/scsi/scsi
        fi
      fi
    fi
    if [ $RC = 0 ] || [ "$forcerescan" ] ; then
      if [ -e "$devpath" ] ; then
        echo 1 > "$devpath/rescan"
      fi
    fi
    printf "\r\e[A\e[A\e[A${yellow}OLD: %s" "$norm"
    testexist
    if [ -z "$SCSISTR" ] && [ $RC != 1 ] && [ "$remappedlun0" != "1" ] ; then
      printf "\r${red}DEL: %s\r\n\n" "$norm"
      # In the event we're replacing with a well known node, we need to let it continue, to create the replacement node
      [ "$remappedlun0" != "2" ] && return 2
    fi
  fi
  if [ -z "$SCSISTR" ] || [ -n "$remappedlun0" ] ; then
    if [ "$remappedlun0" != "2" ] ; then
      # Device does not exist, try to add
      printf "\r${green}NEW: %s" "$norm"
    fi
    if [ -e "/sys/class/scsi_host/host${host}/scan" ] ; then
      echo "$channel $id $lun" > "/sys/class/scsi_host/host${host}/scan" 2> /dev/null
    else
      echo "scsi add-single-device $devnr" > /proc/scsi/scsi
    fi
    testexist
    if [ -z "$SCSISTR" ] ; then
      # Device not present
      printf "\r\e[A";
      # Optimization: if lun==0, stop here (only if in non-remove mode)
      if [ "$lun" = 0 ] && [ -z "$remove" ] && [ "$optscan" = 1 ] ; then
        return 1;
      fi
    else
      if [ "$remappedlun0" != "2" ] ; then
        incrfound "$host:$channel:$id:$lun"
      fi
    fi
  fi
  return 0;
}

# Perform report lun scan on $host $channel $id using REPORT_LUNS
doreportlun()
{
  lun=0
  SCSISTR=
  devnr="$host $channel $id $lun"
  echo -en " Scanning for device $devnr ...\r"
  lun0added=
  #printf "${yellow}OLD: %s" "$norm"
  # Phase one: If LUN0 does not exist, try to add
  testexist -q
  if [ -z "$SCSISTR" ] ; then
    # Device does not exist, try to add
    #printf "\r${green}NEW: %s" "$norm"
    if [ -e "/sys/class/scsi_host/host${host}/scan" ] ; then
      echo "$channel $id $lun" > "/sys/class/scsi_host/host${host}/scan" 2> /dev/null
      udevadm_settle
    else
      echo "scsi add-single-device $devnr" > /proc/scsi/scsi
    fi
    testexist -q
    if [ -n "$SCSISTR" ] ; then
      lun0added=1
      #testonline
    else
      # Device not present
      # return
      # Find alternative LUN to send getluns to
      for dev in /sys/class/scsi_device/${host}:${channel}:${id}:*; do
        [ -d "$dev" ] || continue
        lun=${dev##*:}
        break
      done
    fi
  fi
  targetluns=$(getluns)
  REPLUNSTAT=$?
  lunremove=
  #echo "getluns reports " $targetluns
  olddev=$(find /sys/class/scsi_device/ -name "$host:$channel:$id:*" 2>/dev/null | sort -t: -k4 -n)
  oldtargets="$targetluns"
  # OK -- if we don't have a LUN to send a REPORT_LUNS to, we could
  # fall back to wildcard scanning. Same thing if the device does not
  # support REPORT_LUNS
  # TODO: We might be better off to ALWAYS use wildcard scanning if
  # it works
  if [ "$REPLUNSTAT" = "1" ] ; then
    if [ -e "/sys/class/scsi_host/host${host}/scan" ] ; then
      echo "$channel $id -" > "/sys/class/scsi_host/host${host}/scan" 2> /dev/null
      udevadm_settle
    else
      echo "scsi add-single-device $host $channel $id $SCAN_WILD_CARD" > /proc/scsi/scsi
    fi
    targetluns=$(find /sys/class/scsi_device/ -name "$host:$channel:$id:*" -printf "%f\n" | cut -d : -f 4)
    let found+=$(echo "$targetluns" | wc -l)
    let found-=$(echo "$olddev" | wc -l)
  fi
  [ -z "$targetluns" ] && targetluns="$oldtargets"
  # Check existing luns
  for dev in $olddev; do
    [ -d "$dev" ] || continue
    lun=${dev##*:}
    newsearch=
    inlist=
    # OK, is existing $lun (still) in reported list
    for tmplun in $targetluns; do
      if [ "$tmplun" = "$lun" ] ; then
        inlist=1
        dolunscan $lun0added
        [ $? -eq 1 ] && break
      else
        newsearch="$newsearch $tmplun"
      fi
    done
    # OK, we have now done a lunscan on $lun and
    # $newsearch is the old $targetluns without $lun
    if [ -z "$inlist" ]; then
      # Stale lun
      lunremove="$lunremove $lun"
    fi
    # $lun removed from $lunsearch
    targetluns=${newsearch# }
  done
  # Add new ones and check stale ones
  for lun in $targetluns $lunremove; do
    dolunscan $lun0added
    [ $? -eq 1 ] && break
  done
}

# Perform search (scan $host)
dosearch ()
{
  if [ -z "$channelsearch" ] ; then
    chanlist
  fi
  for channel in $channelsearch; do
    if [ -z "$idsearch" ] ; then
      if [ -z "$lunsearch" ] ; then
	idlist
      else
	idsearch=$(find /sys/bus/scsi/devices -name "target${host}:${channel}:*" -printf "%f\n" | cut -f 3 -d :)
      fi
    fi
    for id in $idsearch; do
      if [ -z "$lunsearch" ] ; then
        doreportlun
      else
        for lun in $lunsearch; do
          dolunscan
          [ $? -eq 1 ] && break
        done
      fi
    done
  done
}

expandlist ()
{
  list=$1
  result=""
  first=${list%%,*}
  rest=${list#*,}
  while [ ! -z "$first" ] ; do
    beg=${first%%-*};
    if [ "$beg" = "$first" ] ; then
      result="$result $beg";
    else
      end=${first#*-}
      result="$result $(seq $beg $end)"
    fi
    [ "$rest" = "$first" ] && rest=""
    first=${rest%%,*}
    rest=${rest#*,}
  done
  echo "$result"
}

searchexisting()
{
  local tmpch;
  local tmpid
  local match=0
  local targets=

  targets=$(find /sys/bus/scsi/devices -name "target${host}:*" -printf "%f\n" | cut -d : -f 2-3)
  # Nothing came back on this host, so we should skip it
  [ -z "$targets" ] && return

  local target=;
  for target in $targets ; do
    channel=${target%:*}
    id=${target#*:}
    if [ -n "$channelsearch" ] ; then
      for tmpch in $channelsearch ; do
        [ $tmpch -eq "$channel" ] && match=1
      done
    else
      match=1
    fi

    [ $match -eq 0 ] && continue
    match=0

    if [ "$filter_ids" -eq 1 ] ; then
      for tmpid in $idsearch ; do
        if [ "$tmpid" = "$id" ] ; then
          match=1
        fi
      done
    else
      match=1
    fi

    [ $match -eq 0 ] && continue

    if [ -z "$lunsearch" ] ; then
      doreportlun
    else
      for lun in $lunsearch ; do
        dolunscan
        [ $? -eq 1 ] && break
      done
    fi
  done
}

# Go through all of the existing devices and figure out any that have been remapped
findremapped()
{
  local hctl=;
  local devs=
  local sddev=
  local id_serial=
  local id_serial_old=
  local remapped=
  mpaths=""
  local tmpfile=

  tmpfile=$(mktemp /tmp/rescan-scsi-bus.XXXXXXXX 2> /dev/null)
  if [ -z "$tmpfile" ] ; then
    tmpfile="/tmp/rescan-scsi-bus.$$"
    rm -f $tmpfile
  fi

  # Get all of the ID_SERIAL attributes, after finding their sd node
  devs=$(ls /sys/class/scsi_device/)
  for hctl in $devs ; do
    if [ -d "/sys/class/scsi_device/$hctl/device/block" ] ; then
      sddev=$(ls "/sys/class/scsi_device/$hctl/device/block")
      id_serial_old=$(udevadm info -q all -n "$sddev" | grep "ID_SERIAL=" | cut -d"=" -f2)
      [ -z "$id_serial_old" ] && id_serial_old="none"
      echo "$hctl $sddev $id_serial_old" >> $tmpfile
    fi
  done

  # Trigger udev to update the info
  echo -n "Triggering udev to update device information... "
  /bin/udevadm trigger
  udevadm_settle 2>&1 /dev/null
  echo "Done"

  # See what changed and reload the respective multipath device if applicable
  while read -r hctl sddev id_serial_old ; do
    remapped=0
    id_serial=$(udevadm info -q all -n "$sddev" | grep "ID_SERIAL=" | cut -d"=" -f2)
    [ -z "$id_serial" ] && id_serial="none"
    if [ "$id_serial_old" != "$id_serial" ] ; then
      remapped=1
    fi
    # If udev events updated the disks already, but the multipath device isn't update
    # check for old devices to make sure we found remapped luns
    if [ -n "$mp_enable" ] && [ $remapped -eq 0 ]; then
      findmultipath "$sddev" $id_serial
      if [ $? -eq 1 ] ; then
        remapped=1
      fi
    fi

    # if uuid is 1, it's unmapped, so we don't want to treat it as a remap
    # if remapped flag is 0, just skip the rest of the logic
    if [ "$id_serial" = "1" ] || [ $remapped -eq 0 ] ; then
      continue
    fi
    printf "${yellow}REMAPPED: %s" "$norm"
    host=$(echo "$hctl" | cut -d":" -f1)
    channel=$(echo "$hctl" | cut -d":" -f2)
    id=$(echo "$hctl" | cut -d":" -f3)
    lun=$(echo "$hctl" | cut -d":" -f4)
    procscsiscsi
    echo "$SCSISTR"
    incrchgd "$hctl"
  done < $tmpfile
  rm -f $tmpfile

  if [ -n "$mp_enable" ] && [ -n "$mpaths" ] ; then
    echo "Updating multipath device mappings"
    flushmpaths
    $MULTIPATH | grep "create:" 2> /dev/null
  fi
}

incrfound()
{
  local hctl="$1"
  if [ -n "$hctl" ] ; then
    let found+=1
    FOUNDDEVS="$FOUNDDEVS\t[$hctl]\n"
  else
    return
  fi
}

incrchgd()
{
  local hctl="$1"
  if [ -n "$hctl" ] ; then
    if ! echo "$CHGDEVS" | grep -q "\[$hctl\]"; then
      let updated+=1
      CHGDEVS="$CHGDEVS\t[$hctl]\n"
    fi
  else
    return
  fi

  if [ -n "$mp_enable" ] ; then
    local sdev

    sdev=$(findsddev "$hctl")
    if [ -n "$sdev" ] ; then
      findmultipath "$sdev"
    fi
  fi
}

incrrmvd()
{
  local hctl="$1"
  if [ -n "$hctl" ] ; then
    let rmvd+=1;
    RMVDDEVS="$RMVDDEVS\t[$hctl]\n"
  else
    return
  fi

  if [ -n "$mp_enable" ] ; then
    local sdev

    sdev=$(findsddev "$hctl")
    if [ -n "$sdev" ] ; then
      findmultipath "$sdev"
    fi
  fi
}

findsddev()
{
  local hctl="$1"
  local sddev=
  local blkpath

  blkpath="/sys/class/scsi_device/$hctl/device/block"
  if [ -e "$blkpath" ] ; then
    sddev=$(ls "$blkpath")
    echo "$sddev"
  fi
}

addmpathtolist()
{
  local mp="$1"
  local mp2=

  for mp2 in $mpaths ; do
    # The multipath device is already in the list
    if [ "$mp2" = "$mp" ] ; then
      return
    fi
  done
  mpaths="$mpaths $mp"
}

findmultipath()
{
  local dev="$1"
  local find_mismatch="$2"
  local mp=
  local mp2=
  local found_dup=0
  local maj_min=

  # Need a sdev, and executable multipath and dmsetup command here
  if [ -z "$dev" ] || [ ! -x "$DMSETUP" ] || [ ! -x "$MULTIPATH" ] ; then
    return 1
  fi

  maj_min=$(cat "/sys/block/$dev/dev")
  for mp in $($DMSETUP ls --target=multipath | cut -f 1) ; do
    [ "$mp" = "No" ] && break;
    if "$DMSETUP" status "$mp" | grep -q " $maj_min "; then
      # With two arguments, look up current uuid from sysfs
      # if it doesn't match what was passed, this multipath
      # device is not updated, so this is a remapped LUN
      if [ -n "$find_mismatch" ] ; then
        mp2=$($MULTIPATH -l "$mp" | egrep -o "dm-[0-9]+")
        mp2=$(cut -f2 -d- "/sys/block/$mp2/dm/uuid")
        if [ "$find_mismatch" != "$mp2" ] ; then
          addmpathtolist "$mp"
          found_dup=1
        fi
        continue
      fi
      # Normal mode: Find the first multipath with the sdev
      # and add it to the list
      addmpathtolist "$mp"
      return
    fi
  done

  # Return 1 to signal that a duplicate was found to the calling function
  if [ $found_dup -eq 1 ] ; then
    return 1
  else
    return 0
  fi
}

reloadmpaths()
{
  local mpath
  if [ ! -x "$MULTIPATH" ] ; then
    echo "no -x multipath"
    return
  fi

  # Pass 1 as the argument to reload all mpaths
  if [ "$1" = "1" ] ; then
    echo "Reloading all multipath devices"
    $MULTIPATH -r > /dev/null 2>&1
    return
  fi

  # Reload the multipath devices
  for mpath in $mpaths ; do
    echo -n "Reloading multipath device $mpath... "
    if $MULTIPATH -r "$mpath" > /dev/null 2>&1 ; then
      echo "Done"
    else
      echo "Fail"
    fi
  done
}

resizempaths()
{
  local mpath

  for mpath in $mpaths ; do
    echo -n "Resizing multipath map $mpath ..."
    multipathd -k"resize map $mpath"
    let updated+=1
  done
}

flushmpaths()
{
  local mpath
  local remove=""
  local i
  local flush_retries=5

  if [ -n "$1" ] ; then
    for mpath in $($DMSETUP ls --target=multipath | cut -f 1) ; do
      [ "$mpath" = "No" ] && break
      num=$($DMSETUP status "$mpath" | awk 'BEGIN{RS=" ";active=0}/[0-9]+:[0-9]+/{dev=1}/A/{if (dev == 1) active++; dev=0} END{ print active }')
      if [ "$num" -eq 0 ] ; then
        remove="$remove $mpath"
      fi
    done
  else
    remove="$mpaths"
  fi

  for mpath in $remove ; do
    i=0
    echo -n "Flushing multipath device $mpath... "
    while [ $i -lt $flush_retries ] ; do
      $DMSETUP message "$mpath" 0 fail_if_no_path > /dev/null 2>&1
      if $MULTIPATH -f "$mpath" > /dev/null 2>&1 ; then
        echo "Done ($i retries)"
        break
      elif [ $i -eq $flush_retries ] ; then
        echo "Fail"
      fi
      sleep 0.02
      let i=$i+1
    done
  done
}


# Find resized luns
findresized()
{
  local devs=
  local size=
  local new_size=
  local sysfs_path=
  local sddev=
  local i=
  local m=
  local mpathsize=
  declare -a mpathsizes

  if [ -z "$lunsearch" ] ; then
    devs=$(ls /sys/class/scsi_device/)
  else
    for lun in $lunsearch ; do
      devs="$devs $(cd /sys/class/scsi_device/ && ls -d *:${lun})"
    done
  fi

  for hctl in $devs ; do
    sysfs_path="/sys/class/scsi_device/$hctl/device"
    if [ -d "$sysfs_path/block" ] ; then
      sddev=$(ls "$sysfs_path/block")
      size=$(cat "$sysfs_path/block/$sddev/size")

      echo 1 > "$sysfs_path/rescan"
      new_size=$(cat "$sysfs_path/block/$sddev/size")

      if [ "$size" != "$new_size" ] && [ "$size" != "0" ] && [ "$new_size" != "0" ] ; then
        printf "${yellow}RESIZED: %s" "$norm"
        host=$(echo "$hctl" | cut -d":" -f1)
        channel=$(echo "$hctl" | cut -d":" -f2)
        id=$(echo "$hctl" | cut -d":" -f3)
        lun=$(echo "$hctl" | cut -d":" -f4)

        procscsiscsi
        echo "$SCSISTR"
        incrchgd "$hctl"
      fi
    fi
  done

  if [ -n "$mp_enable" ] && [ -n "$mpaths" ] ; then
    i=0
    for m in $mpaths ; do
      mpathsizes[$i]="$($MULTIPATH -l "$m" | egrep -o [0-9]+.[0-9]+[KMGT])"
      let i=$i+1
    done
    resizempaths
    i=0
    for m in $mpaths ; do
      mpathsize="$($MULTIPATH -l "$m" | egrep -o [0-9\.]+[KMGT])"
      echo "$m ${mpathsizes[$i]} => $mpathsize"
      let i=$i+1
    done
  fi
}

FOUNDDEVS=""
CHGDEVS=""
RMVDDEVS=""

# main
if [ "@$1" = @--help ] || [ "@$1" = @-h ] || [ "@$1" = "@-?" ] ; then
    echo "Usage: rescan-scsi-bus.sh [options] [host [host ...]]"
    echo "Options:"
    echo " -a      scan all targets, not just currently existing [default: disabled]"
    echo " -c      enables scanning of channels 0 1   [default: 0 / all detected ones]"
    echo " -d      enable debug                       [default: 0]"
    echo " -f      flush failed multipath devices     [default: disabled]"
    echo " -h      help: print this usage message then exit"
    echo " -i      issue a FibreChannel LIP reset     [default: disabled]"
    echo " -I SECS issue a FibreChannel LIP reset and wait for SECS seconds [default: disabled]"
    echo " -l      activates scanning for LUNs 0--7   [default: 0]"
    echo " -L NUM  activates scanning for LUNs 0--NUM [default: 0]"
    echo " -m      update multipath devices           [default: disabled]"
    echo " -r      enables removing of devices        [default: disabled]"
    echo " -s      look for resized disks and reload associated multipath devices, if applicable"
    echo " -u      look for existing disks that have been remapped"
    echo " -V      print version date then exit"
    echo " -w      scan for target device IDs 0--15   [default: 0--7]"
    echo "--alltargets:    same as -a"
    echo "--attachpq3:     Tell kernel to attach sg to LUN 0 that reports PQ=3"
    echo "--channels=LIST: Scan only channel(s) in LIST"
    echo "--color:         use coloured prefixes OLD/NEW/DEL"
    echo "--flush:         same as -f"
    echo "--forceremove:   Remove stale devices (DANGEROUS)"
    echo "--forcerescan:   Remove and readd existing devices (DANGEROUS)"
    echo "--help:          print this usage message then exit"
    echo "--hosts=LIST:    Scan only host(s) in LIST"
    echo "--ids=LIST:      Scan only target ID(s) in LIST"
    echo "--ignore-rev:    Ignore the revision change"
    echo "--issue-lip:     same as -i"
    echo "--issue-lip-wait=SECS:     same as -I"
    echo "--largelun:      Tell kernel to support LUNs > 7 even on SCSI2 devs"
    echo "--luns=LIST:     Scan only lun(s) in LIST"
    echo "--multipath:     same as -m"
    echo "--nooptscan:     don't stop looking for LUNs if 0 is not found"
    echo "--remove:        same as -r"
    echo "--reportlun2:    Tell kernel to try REPORT_LUN even on SCSI2 devices"
    echo "--resize:        same as -s"
    echo "--sparselun:     Tell kernel to support sparse LUN numbering"
    echo "--sync/nosync:   Issue a sync / no sync [default: sync if remove]"
    echo "--update:        same as -u"
    echo "--version:       same as -V"
    echo "--wide:          same as -w"
    echo ""
    echo "Host numbers may thus be specified either directly on cmd line (deprecated)"
    echo "or with the --hosts=LIST parameter (recommended)."
    echo "LIST: A[-B][,C[-D]]... is a comma separated list of single values and ranges"
    echo "(No spaces allowed.)"
    exit 0
fi

if [ "@$1" = @--version ] || [ "@$1" = @-V ] ; then
    echo ${VERSION}
    exit 0
fi

if [ ! -d /sys/class/scsi_host/ ] && [ ! -d /proc/scsi/ ] ; then
  echo "Error: SCSI subsystem not active"
  exit 1
fi

# Make sure sg is there
modprobe sg >/dev/null 2>&1

if [ -x /usr/bin/sg_inq ] ; then
  sg_version=$(sg_inq -V 2>&1 | cut -d " " -f 3)
  if [ -n "$sg_version" ] ; then
    sg_ver_maj=${sg_version:0:1}
    sg_version=${sg_version##?.}
    let sg_version+=$((100 * sg_ver_maj))
  fi
  sg_version=${sg_version##0.}
  #echo "\"$sg_version\""
  if [ -z "$sg_version" ] || [ "$sg_version" -lt 70 ] ; then
    sg_len_arg="-36"
  else
    sg_len_arg="--len=36"
  fi
else
  echo "WARN: /usr/bin/sg_inq not present -- please install sg3_utils"
  echo " or rescan-scsi-bus.sh might not fully work."
fi

# defaults
unsetcolor
debug=0
lunsearch=
opt_idsearch=$(seq 0 7)
filter_ids=0
opt_channelsearch=
remove=
updated=0
update=0
resize=0
forceremove=
optscan=1
sync=1
existing_targets=1
mp_enable=
lipreset=-1
declare -i scan_flags=0
ignore_rev=0

# Scan options
opt="$1"
while [ ! -z "$opt" ] && [ -z "${opt##-*}" ] ; do
  opt=${opt#-}
  case "$opt" in
    a) existing_targets=;;  #Scan ALL targets when specified
    c) opt_channelsearch="0 1" ;;
    d) debug=1 ;;
    f) flush=1 ;;
    i) lipreset=0 ;;
    I) shift; lipreset=$opt ;;
    l) lunsearch=$(seq 0 7) ;;
    L) lunsearch=$(seq 0 "$2"); shift ;;
    m) mp_enable=1 ;;
    r) remove=1 ;;
    s) resize=1; mp_enable=1 ;;
    u) update=1 ;;
    w) opt_idsearch=$(seq 0 15) ;;
    -alltargets)  existing_targets=;;
    -attachpq3) scan_flags=$((scan_flags|0x1000000)) ;;
    -channels=*)  arg=${opt#-channels=};opt_channelsearch=$(expandlist "$arg") ;;
    -color) setcolor ;;
    -flush)       flush=1 ;;
    -forceremove) remove=1; forceremove=1 ;;
    -forcerescan) remove=1; forcerescan=1 ;;
    -hosts=*)     arg=${opt#-hosts=};   hosts=$(expandlist "$arg") ;;
    -ids=*)   arg=${opt#-ids=};         opt_idsearch=$(expandlist "$arg") ; filter_ids=1;;
    -ignore-rev) ignore_rev=1;;
    -issue-lip) lipreset=0 ;;
    -issue-lip-wait) lipreset=${opt#-issue-lip-wait=};;
    -largelun) scan_flags=$((scan_flags|0x200)) ;;
    -luns=*)  arg=${opt#-luns=};        lunsearch=$(expandlist "$arg") ;;
    -multipath) mp_enable=1 ;;
    -nooptscan) optscan=0 ;;
    -nosync) sync=0 ;;
    -remove)      remove=1 ;;
    -reportlun2) scan_flags=$((scan_flags|0x20000)) ;;
    -resize) resize=1;;
    -sparselun) scan_flags=$((scan_flags|0x40)) ;;
    -sync) sync=2 ;;
    -update) update=1;;
    -wide) opt_idsearch=$(seq 0 15) ;;
    *) echo "Unknown option -$opt !" ;;
  esac
  shift
  opt="$1"
done

if [ -z "$hosts" ] ; then
  if [ -d /sys/class/scsi_host ] ; then
    findhosts_26
  else
    findhosts
  fi
fi

if [ -d /sys/class/scsi_host ] && [ ! -w /sys/class/scsi_host ]; then
  echo "You need to run scsi-rescan-bus.sh as root"
  exit 2
fi
[ "$sync" = 1 ] && [ "$remove" = 1 ] && sync=2
if [ "$sync" = 2 ] ; then
  echo "Syncing file systems"
  sync
fi
if [ -w /sys/module/scsi_mod/parameters/default_dev_flags ] && [ $scan_flags != 0 ] ; then
  OLD_SCANFLAGS=$(cat /sys/module/scsi_mod/parameters/default_dev_flags)
  NEW_SCANFLAGS=$((OLD_SCANFLAGS|scan_flags))
  if [ "$OLD_SCANFLAGS" != "$NEW_SCANFLAGS" ] ; then
    echo -n "Temporarily setting kernel scanning flags from "
    printf "0x%08x to 0x%08x\n" "$OLD_SCANFLAGS" "$NEW_SCANFLAGS"
    echo $NEW_SCANFLAGS > /sys/module/scsi_mod/parameters/default_dev_flags
  else
    unset OLD_SCANFLAGS
  fi
fi
DMSETUP=$(which dmsetup)
[ -z "$DMSETUP" ] && flush= && mp_enable=
MULTIPATH=$(which multipath)
[ -z "$MULTIPATH" ] && flush= && mp_enable=

echo -n "Scanning SCSI subsystem for new devices"
[ -z "$flush" ] || echo -n ", flush failed multipath devices,"
[ -z "$remove" ] || echo -n " and remove devices that have disappeared"
echo
declare -i found=0
declare -i updated=0
declare -i rmvd=0

if [ -n "$flush" ] ; then
  if [ -x "$MULTIPATH" ] ; then
    flushmpaths 1
  fi
fi

# Update existing mappings
if [ $update -eq 1 ] ; then
  echo "Searching for remapped LUNs"
  findremapped
  # If you've changed the mapping, there's a chance it's a different size
  mpaths=""
  findresized
# Search for resized LUNs
elif [ $resize -eq 1 ] ; then
  echo "Searching for resized LUNs"
  findresized
# Normal rescan mode
else
  for host in $hosts; do
  echo -n "Scanning host $host "
  if [ -e "/sys/class/fc_host/host$host" ] ; then
    # It's pointless to do a target scan on FC
    issue_lip=/sys/class/fc_host/host$host/issue_lip
    if [ -e "$issue_lip" ] && [ "$lipreset" -ge 0 ] ; then
      echo 1 > "$issue_lip" 2> /dev/null;
      udevadm_settle
      [ "$lipreset" -gt 0 ] && sleep "$lipreset"
    fi
    channelsearch=
    idsearch=
  else
    channelsearch=$opt_channelsearch
    idsearch=$opt_idsearch
  fi
  [ -n "$channelsearch" ] && echo -n "channels $channelsearch "
  echo -n "for "
  if [ -n "$idsearch" ] ; then
    echo -n " SCSI target IDs $idsearch"
  else
    echo -n " all SCSI target IDs"
  fi
  if [ -n "$lunsearch" ] ; then
    echo ", LUNs $lunsearch"
  else
    echo ", all LUNs"
  fi

  if [ -n "$existing_targets" ] ; then
    searchexisting
  else
    dosearch
  fi
  done
  if [ -n "$OLD_SCANFLAGS" ] ; then
    echo "$OLD_SCANFLAGS" > /sys/module/scsi_mod/parameters/default_dev_flags
  fi
fi

let rmvd_found=$rmvd+$found
if [ -n "$mp_enable" ] && [ $rmvd_found -gt 0 ] ; then
  echo "Attempting to update multipath devices..."
  if [ $rmvd -gt 0 ] ; then
    udevadm_settle
    echo "Removing multipath mappings for removed devices if all paths are now failed... "
    flushmpaths 1
  fi
  if [ $found -gt 0 ] ; then
    /bin/udevadm trigger --sysname-match=sd*
    udevadm_settle
    if [ -x "$MULTIPATH" ] ; then
      echo "Trying to discover new multipath mappings for newly discovered devices... "
      $MULTIPATH | grep "create:" 2> /dev/null
    fi
  fi
fi

echo "$found new or changed device(s) found.          "
if [ ! -z "$FOUNDDEVS" ] ; then
  printf "%s" "$FOUNDDEVS"
fi
echo "$updated remapped or resized device(s) found."
if [ ! -z "$CHGDEVS" ] ; then
  printf "%s" "$CHGDEVS"
fi
echo "$rmvd device(s) removed.                 "
if [ ! -z "$RMVDDEVS" ] ; then
  printf "%s" "$RMVDDEVS"
fi

# Local Variables:
# sh-basic-offset: 2
# End: