runltp: add a big loop device

index 63c625f..f491beb 100755
@@ -163,6 +163,9 @@ usage()
     -b DEVICE       Some tests require an unmounted block device
                     to run correctly.
     -B DEVICE_FS_TYPE The file system of test block devices.
+    -z BIG_DEVICE   Some tests require a big unmounted block device
+                    to run correctly.
+    -Z BIG_DEVICE_FS_TYPE The file system of the big device
 
 
     example: ${0##*/} -c 2 -i 2 -m 2,4,10240,1 -D 2,10,10240,1 -p -q  -l /tmp/result-log.$$ -o /tmp/result-output.$$ -C /tmp/result-failed.$$ -d ${PWD}

@@ -207,11 +210,12 @@ main()
     local PAN_COMMAND=""
     local DEFAULT_FILE_NAME_GENERATION_TIME=`date +"%Y_%b_%d-%Hh_%Mm_%Ss"`
     local DEVICE_FS_TYPE="ext2"
+    local BIG_DEVICE_FS_TYPE="ext2"
     local scenfile=
 
     version_date=$(cat "$LTPROOT/Version")
 
-    while getopts a:c:C:d:D:f:F:ehi:K:g:l:m:M:Nno:pqr:s:S:t:T:w:x:b:B: arg
+    while getopts a:c:C:d:D:f:F:ehi:K:g:l:m:M:Nno:pqr:s:S:t:T:w:x:b:B:z:Z: arg
     do  case $arg in
         a)  EMAIL_TO=$OPTARG
             ALT_EMAIL_OUT=1;;

@@ -424,6 +428,8 @@ main()
             INSTANCES="-x $OPTARG";;
         b) DEVICE=$OPTARG;;
         B) DEVICE_FS_TYPE=$OPTARG;;
+        z) BIG_DEVICE=$OPTARG;;
+        Z) BIG_DEVICE_FS_TYPE=$OPTARG;;
         \?) usage;;
         esac
     done

@@ -678,19 +684,37 @@ main()
     }
 
     if [ -n "$DEVICE" ]; then
-        sed -i "s|DEVICE|$DEVICE|"  ${TMP}/alltests
+        sed -i "s|\s+DEVICE\s+|$DEVICE|"  ${TMP}/alltests
         RC=$?
     else
         create_block
         if [ $? -eq 0 ]; then
-            sed -i "s|DEVICE|$DEVICE|"  ${TMP}/alltests
+            sed -i "s|\s+DEVICE\s+|$DEVICE|"  ${TMP}/alltests
             RC=$?
         else
             echo "no block device was specified on commandline."
             echo "Block device could not be created using loopback device"
             echo "Tests which require block device are disabled."
             echo "You can specify it with option -b"
-            sed -i "/DEVICE/d"  ${TMP}/alltests
+            sed -i "/\s+DEVICE\s+/d"  ${TMP}/alltests
+            RC=$?
+        fi
+    fi
+
+    if [ -n "$BIG_DEVICE" ]; then
+        sed -i "s|BIG_DEVICE|$BIG_DEVICE|"  ${TMP}/alltests
+        RC=$?
+    else
+        create_big_block
+        if [ $? -eq 0 ]; then
+            sed -i "s|BIG_DEVICE|$BIG_DEVICE|"  ${TMP}/alltests
+            RC=$?
+        else
+            echo "no big block device was specified on commandline."
+            echo "BIG block device could not be created using loopback device"
+            echo "Tests which require big block device are disabled."
+            echo "You can specify it with option -z"
+            sed -i "/BIG_DEVICE/d"  ${TMP}/alltests
             RC=$?
         fi
     fi

@@ -704,6 +728,10 @@ main()
         sed -i "s|DEVICE_FS_TYPE|$DEVICE_FS_TYPE|"  ${TMP}/alltests
     fi
 
+    if [ -n "$BIG_DEVICE" ]; then
+        sed -i "s|BIG_DEVICE_FS_TYPE|$BIG_DEVICE_FS_TYPE|"  ${TMP}/alltests
+    fi
+
     if [ $? -ne 0 ]; then
         echo "FATAL: error during processing alltests file by sed"
         exit 1

@@ -979,10 +1007,41 @@ create_block()
     fi
 }
 
+create_big_block()
+{
+    # In most systems, the /tmp is relatively small
+    # So create a big block device in LTPROOT
+    BIG_DEVICE_DIR=${LTPROOT}/big_device$$
+    mkdir -p $BIG_DEVICE_DIR
+    dd if=/dev/zero of=${BIG_DEVICE_DIR}/test.img bs=1kB count=5120000 #5G
+    if [ $? -ne 0 ]; then
+        echo "Failed to create loopback device image, please check disk space and re-run"
+        return 1
+    else
+        ##search for an unused loop dev
+        LOOP_BIG_DEV=$(losetup -f)
+        if [ $? -ne 0 ]; then
+            echo "no unused loop device is found"
+            return 1
+        else
+            ##attach the created file to loop dev.
+            losetup $LOOP_BIG_DEV ${BIG_DEVICE_DIR}/test.img
+            if [ $? -ne 0 ]; then
+                echo "losetup failed to create block device"
+                return 1
+            fi
+            BIG_DEVICE=$LOOP_BIG_DEV
+            return 0
+        fi
+    fi
+}
+
 cleanup()
 {
     [ "$LOOP_DEV" ] && losetup -d $LOOP_DEV
+    [ "$LOOP_BIG_DEV" ] && losetup -d $LOOP_BIG_DEV
     rm -rf ${TMP}
+    rm -rf ${BIG_DEVICE_DIR}
 }
 
 trap "cleanup" 0