DataFlash & LFS: fails to format

[pilotak]

Description

Following code worked fine just before #10478

#include <mbed.h>
#include "LittleFileSystem.h"
#include "DataFlashBlockDevice.h"

LittleFileSystem fs("fs");
DataFlashBlockDevice bd(PA_7, PA_6, PA_5, PA_4);

int main() {
    if (bd.init() == BD_ERROR_OK) {
        printf("BD initialized\n");

        if (fs.format(&bd) == BD_ERROR_OK) {
            printf("Storage formated\n");

        } else {
            printf("Storage failed to format\n");
        }

    } else {
        printf("Could not init BD\n");
    }

    return 0;
}

but after that i got an error

BD initialized
lfs info:243: format(0x20000d2c, 64, 64, 512, 512)


++ MbedOS Error Info ++
Error Status: 0x80FF0144 Code: 324 Module: 255
Error Message: Assertion failed: lfs->cfg->block_size % lfs->cfg->prog_size == 0
Location: 0x8004C39
File: .\mbed-os\features\storage\filesystem\littlefs\littlefs\lfs.c+2075
Error Value: 0x0
Current Thread: main  Id: 0x20001344 Entry: 0x8005957 StackSize: 0x1000 StackMem: 0x20001AD0 SP: 0x200028DC
For more info, visit: https://mbed.com/s/error?error=0x80FF0144&tgt=NUCLEO_F303RE
-- MbedOS Error Info --

the workaround is to specify block size directly to format.

fs.format(&bd, MBED_LFS_READ_SIZE, MBED_LFS_PROG_SIZE, 4224, MBED_LFS_LOOKAHEAD)

But is this a correct problem solver? or does MBED_LFS_BLOCK_SIZE need to be changed to 4224 but than if i'm right each file currently takes up an entire block as per documentation.

mbed-os/features/storage/filesystem/littlefs/LittleFileSystem.h

Line 83 in 378e997

* kept small as each file currently takes up an entire block.

MCU: STM32F303RE
Flash: AT45DB161E-SSHD

Issue request type

[ ] Question
[ ] Enhancement
[x] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-1278

[chrissnow]

I suspect that because the default MBED_LFS_BLOCK_SIZE is 512 and you are using native dataflash pages of 4224 the check that pages are multiple of erases is failing,

I'm not sure why it worked before though.

Unless you have a reason for 4224 over 4096 pages try this in your mbed_app.json
"dataflash.binary-size": "1"

I'm not sure why LFS is using defaults from mbed_lib.json rather than taking them from the underlying BD though.

[chrissnow]

This might also work for native dataflash and give you smaller files, erases are 512 or 528 on the 16mb.

fs.format(&bd, MBED_LFS_READ_SIZE, 528, 528, MBED_LFS_LOOKAHEAD)

I can't test it at the moment though.

[pilotak]

thank you, i will try that next week. You raised a lot of questions about LFS it might be good to look at it a bit deeper.

I've had the exact same problem. As @chrissnow pointed out, adding "dataflash.binary-size": 1 to my mbed_app.json resolved the issue.
According to the debug traces from LFS, the issue seems to be a mismatch in lfs->cfg->block_size % lfs->cfg->prog_size so the result is not 0. In my case I had block_size = 528 and prog_size = 64 so the remaining is 16 (528 mod 64 = 16), thus the assertion fails. I'm not sure whether that an issue with the default values from the DataFlash API for the PROG_SIZE parameter.
I at least couldn't find proper documentation for the binary-size option.

[pilotak]

@chrissnow Here are some results:

• with no overriding in mbed_app.json and fs.format(&bd, MBED_LFS_READ_SIZE, 528, 528, MBED_LFS_LOOKAHEAD) there is an format storage error (mbed error)

• with no overriding in mbed_app.json and fs.format(&bd, MBED_LFS_READ_SIZE, 528, 4224, MBED_LFS_LOOKAHEAD) there is an format storage error (mbed error)

• with "littlefs.block_size": 528 in mbed_app.json and fs.format(&bd, MBED_LFS_READ_SIZE, MBED_LFS_PROG_SIZE, 4224, MBED_LFS_LOOKAHEAD) storage is formatted but mount() fails

• with "littlefs.block_size": 4224 in mbed_app.json and fs.mount(&bd) there is an format storage error (mbed error)

• with "littlefs.block_size": 4224 in mbed_app.json and fs.mount(&bd, MBED_LFS_READ_SIZE, 528, MBED_LFS_BLOCK_SIZE, MBED_LFS_LOOKAHEAD) there is an format storage error (mbed error)

• with "littlefs.block_size": 4224 and "littlefs.prog_size": 528 in mbed_app.json and fs.mount(&bd) there no mbed error it fails to format

• with "dataflash.binary-size": 1 in mbed_app.json and fs.mount(&bd) surprisingly no problems even though flash is not binary-sized

So in order to get dataflash up and running for beginers there should be binary size set to 1 as default if i'm right

mbed-os/components/storage/blockdevice/COMPONENT_DATAFLASH/mbed_lib.json

Line 11 in 608e4c2

"value": "0"

I also want to point out that this was a breaking change without (IMHO) any proper documentation on how to get the same behaviour as a previous version of the OS or what changes would be needed at all. I didn't see any relevant information to this error in the release notes or the online documentation.

[0xc0170]

@vidavidorra Thanks for the feedback. How did 10478 break your code (@chrissnow added release notes section in PR , they should be in the 5.13 release notes) ?

I would like to get details for this one, to understand what should have raised red flag in that PR.

[0xc0170]

@pilotak I'll close this issue as it seems it was answered. The remaining question is about the breakage (if it was not properly handled) - can be discussed further with issue closed.

@0xc0170 To be honest, I'm not sure that #10478 specifically broke my code. All I know is that somewhere between v5.11.6 and v5.13.0 it became required to set "dataflash.binary-size": "1" in order to get the same functionality I had in v5.11.6. I didn't see that documented in the release notes between that range so unfortunately can't tell you where it went wrong. Anyhow, "dataflash.binary-size": "1" fixed my issue regardless from where it is originated.
What I do want to note is that that option isn't documented in the v5.13.0 docs so IMHO that should be added and than its fine.

[pilotak]

well basically with option "dataflash.binary-size": "0" it doens't work