sata

#!/bin/bash
#============================================================================================#
# Copyright (C) 2014
# Author: Alban 
#
# Description
# -----------
# This script provides functionality for SATA disks on Linux system :
#   - remove disk
#   - scan host for new disks
#
#============================================================================================#
#============================================================================================#
# SCRIPT SETTINGS
#============================================================================================#
ISROOTREQUIRED=1 # Use 0 if you want to run it with non-root users
FORCEARGUMENTSREQUIRED=0 # Use 0 if you want to run it without arguments
#============================================================================================#
# Variables
#============================================================================================#
BN=${0##*/}
MYPID=$(echo $$)
#============================================================================================#
# ERROR CODES
#============================================================================================#
	ROOTISREQUIRED=100
	NOPARAMETERSPROVIDED=101
	CUSTOM_ERROR2=102
	PARAMISREQUIRED=103
	PARAMSDX=104
	HOSTDIR=105
	HOSTDIR=106
	INVALIDMD=107
	INVALIDBD=108
#============================================================================================#
# COMMON FUNCTIONS
#============================================================================================#
exit_usage()
{
    ERRCODE=$1
	MSG=$2
	if [[ -z $MSG ]] ; then
	cat <<StartHere
NAME ${BN}
SYNOPSIS
  ${BN} [-h] [scan||remove <block>]
DESCRIPTION
  scan	    Will scan all the SATA hosts to refresh disks
  remove    Will remove one disk IF not used in RaidMD
EXAMPLE
  ${BN} scan
  ${BN} remove $BLOCK_DEVICE
StartHere
	else
		echo $MSG
	fi
	exit $ERRCODE
} # end exit_usage()

isRoot() # This method check if the current user is root
{
    if [ "root" != "$( whoami )" ] && [ $ISROOTREQUIRED -eq 1 ] ; then
	echo "${BN} must be run as root"
	    exit_usage $ROOTISREQUIRED
	    fi
}


#============================================================================================#
# Main methods 
#============================================================================================#
scan()
{
    echo "Scanning host"
    for s in `find /sys/devices/ -name "*scsi_host"`; do 
	echo "scanning $s"
	FILE=`find $s -name "scan"`
	echo "- - - " > $FILE 
    done;
}
remove()
{
    # Check parameter
    BLOCK_DEVICE="$1"
	REGEX="^sd[[:lower:]]$"

    if [ -z "$BLOCK_DEVICE" ] ; then
		exit_usage $PARAMISREQUIRED "You must provide a valid disk name as parameter eg. sdX"
	fi
	if [[ ! $BLOCK_DEVICE =~ $REGEX ]] ; then
		exit_usage $PARAMSDX "Invalid device, please provide a 'sdX'"
	fi

    echo "Checking if block device exists..."
	SYS=(find /sys/block -name $BLOCK_DEVICE)
	if [ -z $SYS ] ; then exit_usage $INVALIDBD "You provided an invalid block device"; fi

    echo "Checking mdraid usage..."
	MD=$(grep $BLOCK_DEVICE[0-9] /proc/mdstat)
	if [ 0 = $? ] ; then exit_usage $INVALIDMD "You provided o block device still used in MD array"; fi

    echo "Finding block device host..."
	HOST_DIR=`cd $(dirname /sys/block/$BLOCK_DEVICE) && cd $(readlink /sys/block/$BLOCK_DEVICE)/../../../../ && pwd`
	if [ ! -d $HOST_DIR ] ; then exit_usage $HOSTDIR "Could not find host directory for $BLOCK_DEVICE"; fi
	DELETE=`find $HOST_DIR -name delete`
	if [ -z $DELETE ] ; then exit_usage $HOSTDELETE "Could not find host delete access for $BLOCK_DEVICE"; fi
	echo $DELETE
	#echo "1" > $DELETE


}


#============================================================================================#
# Startup code (This section contains logic that occurs before processing the arguments)
#============================================================================================#
# Checking if the script was executed as root (it may disabled by setting ISROOTREQUIRED as 0)
isRoot
# Check if arguments are set (it may disabled by setting FORCEARGUMENTSREQUIRED as 0)
if [ $# -eq 0 ] && [ $FORCEARGUMENTSREQUIRED -eq 1 ]
then
echo "You need to provide parameters"
exit_usage $NOPARAMETERSPROVIDED
fi
#============================================================================================#
# Script argument processing
#============================================================================================#

ACTION=$1
case $ACTION in
    (scan) scan;;
    (remove) remove "$2";;
    (*) exit_usage;;
esac



###
# Finish Bash script with Error CODE 0 = Everything is normal
###
exit 0