frag.sh

[zhangshida <starzhangzsd@xxxxxxxxx>]

From: Shida Zhang <zhangshida@xxxxxxxxxx>

#usage: ./frag.sh $dev $dir $size_k $filename 
#!/bin/bash

cleanup() {
	echo "Ctrl+C detected. Killing child processes..." >&2
	pkill -P $$ # Kill all child processes
	echo "exit...umount ${test_dev}" >&2
	umount ${test_dev}
	exit 1
}
trap cleanup SIGINT SIGTERM

test_dev=$1
if [ -z $test_dev ]; then
	echo "test_dev cant be null"
	echo "usage: ./create_file.sh [test_dev] [test_dir] [file_size_k]"
	exit 1
fi
test_mnt=$2
if [ -z $test_mnt ]; then
	echo "test_mnt cant be null"
	echo "usage: ./create_file.sh [test_dev] [test_dir] [file_size_k]"
	exit 1
fi
file_size_k=$3
if [ -z ${file_size_k} ]; then
	echo "file_size_k cant be null"
	echo "usage: ./create_file.sh [test_dev] [test_dir] [file_size_k]"
	exit 1
fi
echo "test_dev:${test_dev} test_mnt:${test_mnt} fize_size:${file_size_k}KB"

#mkfs.xfs -f ${test_dev}

if [ $5 -eq 0 ]; then
	echo "mount ${test_dev} ${test_mnt}"
	mount $test_dev $test_mnt
else
	echo "mount -o af1=1 ${test_dev} ${test_mnt}"
	mount -o af1=1 $test_dev $test_mnt
fi



# Parameters

FILE=${test_mnt}/"$4"   # File name
echo "$FILE"
if [ -z ${FILE} ]; then
	FILE=${test_mnt}/"fragmented_file"   # File name
fi
TOTAL_SIZE=${file_size_k}	# Total size in KB
CHUNK_SIZE=4             # Size of each punch operation in KB


# Create a big file with allocated space
xfs_io -f -c "falloc 0 $((TOTAL_SIZE))k" $FILE

# Calculate total number of punches needed
NUM_PUNCHES=$(( TOTAL_SIZE / (CHUNK_SIZE * 2) ))

last_percentage=-1
# Punch holes alternately to create fragmentation
for ((i=0; i<NUM_PUNCHES; i++)); do
    OFFSET=$(( i * CHUNK_SIZE * 2 * 1024 ))
    xfs_io -c "fpunch $OFFSET ${CHUNK_SIZE}k" $FILE
    
    # Calculate current percentage and print if changed
    PERCENTAGE=$(( (i + 1) * 100 / NUM_PUNCHES ))
    if [ "$PERCENTAGE" -ne "$last_percentage" ]; then
        #echo "Processing...${PERCENTAGE}%"
        last_percentage=$PERCENTAGE
    fi
done

# Verify the extent list (to see fragmentation)
# echo "Extent list for the file:"
# xfs_bmap -v $FILE
df -Th ${test_mnt}

echo "umount ${test_dev}"
umount $test_dev

xfs_db -c 'freesp' $test_dev