sector allignments in FATfs on external flash with STM32F767

[AShel.1]

I'm using FATfs file system on external flash (16MB) using STM32F767, I'm able to create/ read/ write/ close files.

I've created 4 files: sequence of handing files and sector no assigned to them are as,

Created/ Write File1 - sector 8

Created/ Write File2 - sector 9

Created/ Write File3 - sector 10

unlink File2

Created/ Write File4 - sector 11

before creating File 4 I've deleted File 2 using f_unlink("0:/FILE2.TXT"); function, now I expect if I create File4 then sector no 9 should be assigned to this file as it is free sector after File2 is deleted. Is there any way to reused the free sector after deleting files.

if(f_open(&MyFile, "0:/FILE1.TXT", FA_READ | FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)//FA_CREATE_ALWAYS | FA_WRITE
	 {
	 /* 'STM32.TXT' file Open for write Error */
	 Error_Handler();
	 }
	 else
	 {
	 /* Write data to the text file */
	 res = f_write(&MyFile, wtext, sizeof(wtext), (void *)&byteswritten);
 
	 if((byteswritten == 0) || (res != FR_OK))
	 {
	 /* 'STM32.TXT' file Write or EOF Error */
	 Error_Handler();
	 }
	 else
	 {
	 		if(f_open(&MyFile2, "0:/FILE2.TXT", FA_READ | FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)//FA_CREATE_ALWAYS | FA_WRITE
	 	 {
	 	 /* 'STM32.TXT' file Open for write Error */
	 	 Error_Handler();
	 	 }
	 
	 else
	 {
	 	res = f_write(&MyFile2, wtext2, sizeof(wtext2), (void *)&byteswritten);
 
	 		 if((byteswritten == 0) || (res != FR_OK))
	 		 {
	 		 /* 'STM32.TXT' file Write or EOF Error */
	 		 Error_Handler();
	 		 }
	 		 
	 /* Read data from the text file */
	 		 if(f_open(&MyFile3, "0:/FILE3.TXT", FA_READ | FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)//FA_CREATE_ALWAYS | FA_WRITE
	 		 	 {
	 		 	 /* 'STM32.TXT' file Open for write Error */
	 		 	 Error_Handler();
	 		 	 }
	 		 	 else
	 		 	 {
	 		 	 /* Write data to the text file */
	 		 	 res = f_write(&MyFile3, wtext, sizeof(wtext), (void *)&byteswritten);
 
	 		 	 if((byteswritten == 0) || (res != FR_OK))
	 		 	 {
	 		 	 /* 'STM32.TXT' file Write or EOF Error */
	 		 	 Error_Handler();
	 		 	 }
	 		 	 else
	 		 	 {
 
	 		 	 }
	 		 	 }
	 		 f_unlink("0:/FILE2.TXT");	 		 
	 		 
	 		 if(f_open(&MyFile4, "0:/FILE4.TXT", FA_READ | FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)//FA_CREATE_ALWAYS | FA_WRITE
	 		 	 		 	 {
	 		 	 		 	 /* 'STM32.TXT' file Open for write Error */
	 		 	 		 	 Error_Handler();
	 		 	 		 	 }
	 		 	 		 	 else
	 		 	 		 	 {
	 		 	 		 	 /* Write data to the text file */
	 		 	 		 	 res = f_write(&MyFile4, wtext, sizeof(wtext), (void *)&byteswritten);
 
	 		 	 		 	 if((byteswritten == 0) || (res != FR_OK))
	 		 	 		 	 {
	 		 	 		 	 /* 'STM32.TXT' file Write or EOF Error */
	 		 	 		 	 Error_Handler();
	 		 	 		 	 }
	 		 	 		 	 else
	 		 	 		 	 {
 
	 		 	 		 	 }
	 		 	 		 	 }