I had similar problems trying smart FS with a large device. It was over a year
ago, and I put it on the back burner at the time, but I am sure there was
something that exceeded the max value of a 16 bit integer somewhere and it went
wrong. To me it seemed like it wasn't suited to large devices "out of the box"
and needed some work.
I would be delighted if this is sorted; otherwise I'll be looking at again
sometime in the next few months.
>-----Original Message-----
>From: Daniel Pereira Carvalho <daniel...@gmail.com>
>Sent: 20 October 2022 13:16
>To: dev@nuttx.apache.org
>Subject: Re: Is SmartFS limited to 16M memories
>
>Hi Ken,
>
>First of all, thanks for your quick response.
>
>One of the first things I tried was to change the values of
>MTD_SMART_SECTOR_SIZE [=2048] and MTD_SMART_SECTOR_CACHE_SIZE
>[=2048] but the smartfs_mount() is still failing to validate the low-level
>format.
>For reference the struct fs->fs_llformat has the following values just before
>the error
>
>fs->fs_llformat.sectorsize:2048
>fs->fs_llformat.availbytes:2043
>fs->fs_llformat.nsectors:16384
>fs->fs_llformat.nfreesectors:16378
>fs->fs_llformat.flags:0 '\000'
>fs->fs_llformat.namesize:16 '\020'
>
>Changing the capacity to W25_JEDEC_CAPACITY_128MBIT and keeping
>MTD_SMART_SECTOR_SIZE and MTD_SMART_SECTOR_CACHE_SIZE the same
>[2048] the file system works as expected. For reference the struct fs-
>>fs_llformat has the following values just before the function validates the
>low level format.
>
>fs->fs_llformat.sectorsize:2048
>fs->fs_llformat.availbytes:2043
>fs->fs_llformat.nsectors:8192
>fs->fs_llformat.nfreesectors:8183
>fs->fs_llformat.flags:1 '\001'
>fs->fs_llformat.namesize:16 '\020'
>
>Thanks
>
>Daniel Pereira de Carvalho
>
>Em qua., 19 de out. de 2022 às 21:26, Ken Pettit <petti...@gmail.com>
>escreveu:
>
>> Hi Daniel,
>>
>> The SmartFS FS *can* work with devices greater than 16M Bytes. I have
>> used it with a 256MBit / 32M Byte SPI flash before quite successfully.
>>
>> But you have to ensure the logical sector size is large enough. One
>> limitation of the SMART MTD (and therefore SMART FS) implementation is
>> that it uses unsigned 16-bit integers for logical sector numbers.
>> This means you can only have 65536 maximum logical sectors (actually a
>> few less than that, but the code knows how to deal with 65536 values
>> and simply "waste" a few reserved values like zero and 0xFFFF).
>>
>> This means that for a 32M byte flash, you would need to ensure the
>> logical sector size is at least 32M / 65536 = 512 bytes. Typically
>> for the SMART MTD layer, a logical sector size of 1024 or 2048 (or
>> larger) is preferred because the code can manage erase blocks / free
>> sector collection management better.
>>
>> In your 'make menuconfig', check your SMART logical sector size and try
>> setting it to 2048. For the W25256JEVIEQ part with 256-byte pages,
>> this will be 8 pages per logical sector, which is a good setting. Of
>> course this also means that the smallest file size is 2K bytes, even
>> if the file only has 1 byte stored in it. That's the price you pay
>> for a structured file system though.
>>
>> Ken
>>
>>
>> On 10/19/22 4:39 PM, Daniel Pereira Carvalho wrote:
>> > Hi guys,
>> >
>> > I am trying to use the memory W25Q256JVEIQ, with SMARTS FS. To do it
>> > I added the support for this memory in "drivers/mtd/w25.c". I just
>> > added
>> the
>> > code below
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > *..#define W25_JEDEC_CAPACITY_256MBIT 0x19 /* 8192x4096 = 256Mbit
>> > memory capacity */../* 256M-bit / 32M-byte (33,554,432) * *
>> > W25Q256JV (Standard
>> > SPI) */else if (capacity == W25_JEDEC_CAPACITY_256MBIT) {
>> > priv->nsectors = NSECTORS_256MBIT; }..*
>> >
>> > The memory initialization seems to go well. I can run the mksmartfs
>> > utility, mount and write to the filesystem. However when I reboot
>> > the
>> board
>> > I can't mount the filesystem again. The function smartfs_mount()
>> > returns the error "ERROR: No low-level format found".
>> >
>> > The documentation says that SMARTS FS is designed to work with 1M
>> > byte to 16M byte in size (though this is not a limitation). So I
>> > changed the
>> > priv->nsectors from NSECTORS_256MBIT to NSECTORS_128MBIT to see if
>> > priv->the
>> > problem was with the size of the memory. After this change the file
>> system
>> > started to work as expected.
>> >
>> > Should SMARTS FS work with memories larger than 16M, since in the
>> > docs it is said that this is not a limitation? If SMART FS is
>> > limited to memories smaller than 16M do you recommend another
>filesystem?
>> >
>> > Thanks
>> >
>> > Daniel Pereira de Carvalho
>> >
>>
>>
