fds garbage. Invalid offset on new page.

[Petr]

SDK 4.0.0-2.alpha

When run garbage collection, sometimes invalid offset on new page is present. Adding next string fix this. m_swap_page.write_offset = FDS_PAGE_TAG_SIZE; // [FIX]

I did correctly?

Full function text:

static ret_code_t gc_swap()

{ uint32_t ret; uint16_t const gc = m_gc.cur_page;

CRITICAL_SECTION_ENTER();
uint16_t const records_open = m_pages[gc].records_open;
CRITICAL_SECTION_EXIT();

if (records_open == 0)
{
    /** The page being GC will be the new swap, and the current swap
     *  will be used as a valid page. */
    uint32_t const * const p_addr = m_swap_page.p_addr;

    m_swap_page.p_addr = m_pages[gc].p_addr;
    m_pages[gc].p_addr = p_addr;

    m_pages[gc].write_offset = m_swap_page.write_offset;

    // Erase the new swap page.
    ret = fs_erase(&fs_config, m_swap_page.p_addr, FDS_PHY_PAGES_IN_VPAGE);

    m_swap_page.write_offset = FDS_PAGE_TAG_SIZE; // [FIX]
    
    m_gc.state = GC_TAG_VALID;
}
else
{
    /** If there are open records, we can't GC the page anymore.
     *  Discard the swap and try to GC another page. */
    ret = gc_erase_swap();
}

return ret;

}

[Håkon Alseth]

Hi Petr,

I can confirm the issue that you are seeing, and the validity of your workaround.

I had a chat with the developers of FDS, and looked into the internal repository. They have actually implemented the same fix that you have found, and this will be included in the next release of the SDK.

Best regards, Håkon