No space left on device, but write data success

[yplwrt]

DEBUG:
littlefs/lfs.c:497:error: No more free space 441
LINE 116: lfs write data length: 256

Code:
const struct lfs_config g_lfs_cfg = {

	// block device operations
	  .read  = user_provided_block_device_read,
	  .prog  = user_provided_block_device_prog,
	  .erase = user_provided_block_device_erase,
	  .sync  = user_provided_block_device_sync,
	
	  // block device configuration
	  .read_size = 256,
	  .prog_size = 256,
	  .block_size = 4096,
	  .block_count = 256,
	  .cache_size = 256,
	  .lookahead_size = 32,
	  .block_cycles = 500,
};

		err = lfs_file_open(&g_lfs, &g_lfs_file[0], lfs_read_buf1, LFS_O_RDWR | LFS_O_CREAT);		
		if(err) 
			printf("lfs open error:%d  LINE %d\n", err,  __LINE__);			

		err = lfs_file_write(&g_lfs, &g_lfs_file[0], lfs_write_buf, sizeof(lfs_write_buf));
		if (err > 0)
			printf("LINE %d: lfs write data length:%d\n", __LINE__,  err);
		
		lfs_file_close(&g_lfs, &g_lfs_file[0]);

---

QUESTION:
When the flash space is exhausted, an error should be reported when writing data again, but now the lfs_file_write() function does not report an error. why?

[Johnxjj]

Inline file？

[w366813640]

DEBUG:

littlefs/lfs.c:497:error: No more free space 441
LINE 116: lfs write data length: 256
Code:
const struct lfs_config g_lfs_cfg = {

// block device operations
  .read  = user_provided_block_device_read,
  .prog  = user_provided_block_device_prog,
  .erase = user_provided_block_device_erase,
  .sync  = user_provided_block_device_sync,

  // block device configuration
  .read_size = 256,
  .prog_size = 256,
  .block_size = 4096,
  .block_count = 256,
  .cache_size = 256,
  .lookahead_size = 32,
  .block_cycles = 500,

};
err = lfs_file_open(&g_lfs, &g_lfs_file[0], lfs_read_buf1, LFS_O_RDWR | LFS_O_CREAT);
if(err)
printf("lfs open error:%d LINE %d\n", err, LINE);

	err = lfs_file_write(&g_lfs, &g_lfs_file[0], lfs_write_buf, sizeof(lfs_write_buf));
	if (err > 0)
		printf("LINE %d: lfs write data length:%d\n", __LINE__,  err);
	
	lfs_file_close(&g_lfs, &g_lfs_file[0]);

QUESTION:
When the flash space is exhausted, an error should be reported when writing data again, but now the lfs_file_write() function does not report an error. why?

I have met the same issue, want to know the reason.

[geky]

If I understand correctly, you are calling write after open returns LFS_ERR_NOSPC?

littlefs doesn't handle this, the file is left uninitialized if lfs_file_open errors.

So the correct code would be something like this:

err = lfs_file_open(&g_lfs, &g_lfs_file[0], lfs_read_buf1, LFS_O_RDWR | LFS_O_CREAT);       
if(err) 
    printf("lfs open error:%d  LINE %d\n", err,  __LINE__);         

if (!err) {
    err = lfs_file_write(&g_lfs, &g_lfs_file[0], lfs_write_buf, sizeof(lfs_write_buf));
    if (err > 0)
        printf("LINE %d: lfs write data length:%d\n", __LINE__,  err);
    
    err = lfs_file_close(&g_lfs, &g_lfs_file[0]);
    if(err) 
        printf("lfs close error:%d  LINE %d\n", err,  __LINE__);     
}

We recently added some checks that assert in this case, but they require that asserts are enabled (#443)

[JonJust]

Hey there,

You wouldn't happen to be developing for the winbond w25, would you? What does your disk io look like?