Available space

[davidefer]

Hi
first of all thank you very much for having developed littlefs.

I have a question concerning the available space on the storage: how to calculate it?
Thank you in advance.

[guillaumerems]

Hi davidefer,
Here is my implementation of a df function:

static int _traverse_df_cb(void *p, lfs_block_t block){
	uint32_t *nb = p;
	*nb += 1;
	return 0;
}
static int _df(void){
	int err;

	uint32_t _df_nballocatedblock = 0;
	err = lfs_traverse(&_lfs, _traverse_df_cb, &_df_nballocatedblock);
	if(err < 0){
		return err;
	}

	uint32_t available = _lfs_cfg.block_count*BLOCK_SIZE- _df_nballocatedblock*BLOCK_SIZE;

	return available;
}

It counts the allocated block then as we know the number of total block we can know how many block are available

[davidefer]

Thank you guillaumerems, it works.
Do you know if it would be possible to get the amount of bad blocks (blocks which have reported an error while writing/erasing)?

[geky]

Thanks @guillaumerems!

It sounds like we should probably add a lfs_fs_size function or something since this feature has been requested fairly often.

@davidefer, littlefs itself doesn't actually know which blocks are bad until it tries to write to them. It just doesn't store this information.

[geky]

I went ahead and tacked on a lfs_fs_size function to this pr #48 so it should be in v1.4. Hopefully that will be easier to use.

[tomvarghese]

I tried this code and it works if I mount the fs and check before and after an operation. However, if I unmount and remount, this number appears to reset to the original value before I did the operation. Am I missing something simple?

[geky]

@tomvarghese, that should not happen. Is it possible to create a small program that reproduces this? Thanks.

[tomvarghese]

I just found the problem yesterday evening. It was a bug in my code, was not closing the file before unmounting. Thanks for your response though. Really appreciate it. Tom From: Christopher Haster <[email protected]> Sent: Monday, April 1, 2019 12:57 AM To: ARMmbed/littlefs <[email protected]> Cc: Thomas Varghese <[email protected]>; Mention <[email protected]> Subject: Re: [ARMmbed/littlefs] Available space (#45) @tomvarghese<https://github.com/tomvarghese>, that should not happen. Is it possible to create a small program that reproduces this? Thanks. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#45 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AN9FN1bcJpYOSiIrRxe5D-ufOhXGpfRCks5vcZ-YgaJpZM4S-txS>.