br: fix unstable test br_300_small_tables (#46560) (#46568)

close #46561

br/tests/br_300_small_tables/run.sh

@@ -43,7 +43,7 @@ unset BR_LOG_TO_TERM
 rm -f $BACKUPMETAV2_LOG
 export GO_FAILPOINTS="github.com/pingcap/tidb/br/pkg/task/progress-call-back=return(\"$PROGRESS_FILE\")"
 run_br backup db --db "$DB" --log-file $BACKUPMETAV2_LOG -s "local://$TEST_DIR/${DB}v2" --pd $PD_ADDR --use-backupmeta-v2 
-backupv2_size=`grep "backup-data-size" "${BACKUPMETAV2_LOG}" | grep -oP '\[\K[^\]]+' | grep "backup-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.\d+'`
+backupv2_size=`grep "backup-data-size" "${BACKUPMETAV2_LOG}" | grep -oP '\[\K[^\]]+' | grep "backup-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.?\d+'`
 echo "backup meta v2 backup size is ${backupv2_size}"
 export GO_FAILPOINTS=""
 
@@ -61,7 +61,7 @@ rm -rf $PROGRESS_FILE
 echo "backup meta v1 start..."
 rm -f $BACKUPMETAV1_LOG
 run_br backup db --db "$DB" --log-file $BACKUPMETAV1_LOG -s "local://$TEST_DIR/$DB" --pd $PD_ADDR 
-backupv1_size=`grep "backup-data-size" "${BACKUPMETAV1_LOG}" | grep -oP '\[\K[^\]]+' | grep "backup-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.\d+'`
+backupv1_size=`grep "backup-data-size" "${BACKUPMETAV1_LOG}" | grep -oP '\[\K[^\]]+' | grep "backup-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.?\d+'`
 echo "backup meta v1 backup size is ${backupv1_size}"
 
 
@@ -83,7 +83,7 @@ done
 rm -rf $RESTORE_LOG
 echo "restore 1/300 of the table start..."
 run_br restore table --db $DB  --table "sbtest100" --log-file $RESTORE_LOG -s "local://$TEST_DIR/$DB" --pd $PD_ADDR --no-schema
-restore_size=`grep "restore-data-size" "${RESTORE_LOG}" | grep -oP '\[\K[^\]]+' | grep "restore-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.\d+'`
+restore_size=`grep "restore-data-size" "${RESTORE_LOG}" | grep -oP '\[\K[^\]]+' | grep "restore-data-size" | awk -F '=' '{print $2}' | grep -oP '\d*\.?\d+'`
 echo "restore data size is ${restore_size}"
 
 diff=$(calc "$backupv2_size-$restore_size*$TABLES_COUNT")