Re: [PATCH] spi: rspi: fix the bug related to mount/remount jffs2

[DongCV <cv-dong@jinso.co.jp>]

Dear Geert,

Thank you for your reply.

>> diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
>> index 9daf500..2ee1301 100644
>> --- a/drivers/spi/spi-rspi.c
>> +++ b/drivers/spi/spi-rspi.c
>> @@ -848,7 +848,6 @@ static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
>>                        ret = rspi_pio_transfer(rspi, NULL, rx, n);
>>                        if (ret < 0)
>>                                return ret;
>> -                     *rx++ = ret;
> Storing the success code (0) in the receive buffer is indeed wrong.
>
> However, there are other bugs in that code:
>
> rspi_pio_transfer(rspi, NULL, rx, n) transfers n bytes instead of len,
> while n is decreased by len (which is <= n).
> Furthermore rx is not incremented.
> Hence if len < n, n will still be non-zero, and a new iteration of the
> loop will be started, trying to receive more data, and overwriting the
> just filled buffer.
>
> The same bug is present in qspi_transfer_out().
>
>>                }
>>                n -= len;
>>        }
>> --
>> 1.9.1
>>
(nip)
> Apart from sending patches inline, my comments from
> https://www.spinics.net/lists/linux-spi/msg09753.html are still valid.

Sorry I might not understand your explanation correctly. Could you 
please explain it more details?
(Because I've tried to understand your explanation then analyzed the 
source code again as below:
https://patchwork.kernel.org/patch/9541629/)

Thank you.
Dong



On 02/06/2017 08:02 PM, Geert Uytterhoeven wrote:
> Hi Dong,
>
> On Mon, Feb 6, 2017 at 2:02 AM, DongCV <cv-dong@jinso.co.jp> wrote:
>> From: Dong <cv-dong@jinso.co.jp>
>>
>> This patch fixes the output warning logs and data loss when
>> performing mount/umount then remount the device with jffs2 format.
>>
>> This is the warning logs when performing mount/umount then remount the device with jffs2 format:
>> "root@linaro-naro:~# mount -t jffs2 /dev/mtdblock2 /mnt/media
>> [ 3839.928013] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40000: 0x1900 instead
>> [ 3839.956515] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40004: 0x000c instead
>> [ 3839.985009] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40008: 0xb0b1 instead
>> [ 3840.013591] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b4000c: 0x1900 instead
>> [ 3840.042087] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40010: 0x0044 instead
>> [ 3840.070566] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40014: 0xfb1d instead
>> [ 3840.099159] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40018: 0x0002 instead
>> [ 3840.127604] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b4001c: 0x0001 instead
>> [ 3840.156043] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40020: 0x81a4 instead
>> [ 3840.184472] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b4002c: 0x6529 instead
>> [ 3840.212900] jffs2: Further such events for this erase block will not be printed
>> [ 3840.322915] jffs2: notice: (2008) read_dnode: node CRC failed on dnode at 0x3b40080: read 0xc40b5dfc, calculated 0x264be003
>> root@linaro-naro[ 3840.356857] jffs2: warning: (2008) jffs2_do_read_inode_internal: no data nodes found for ino #2
>> :~# [ 3840.386659] jffs2: Returned error for crccheck of ino #2. Expect badness...
>>
>> Signed-off-by: Dong <cv-dong@jinso.co.jp>
>> ---
>>   drivers/spi/spi-rspi.c | 1 -
>>   1 file changed, 1 deletion(-)
>>
>> diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
>> index 9daf500..2ee1301 100644
>> --- a/drivers/spi/spi-rspi.c
>> +++ b/drivers/spi/spi-rspi.c
>> @@ -848,7 +848,6 @@ static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
>>                          ret = rspi_pio_transfer(rspi, NULL, rx, n);
>>                          if (ret < 0)
>>                                  return ret;
>> -                       *rx++ = ret;
>>                  }
>>                  n -= len;
>>          }
> Apart from sending patches inline, my comments from
> https://www.spinics.net/lists/linux-spi/msg09753.html are still valid.
>
> Gr{oetje,eeting}s,
>
>                          Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds
>