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

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Dong,

On Fri, Jan 27, 2017 at 9:12 AM, DongCV <cv-dong@xxxxxxxxxxx> wrote:
> This patch fixes the output warning logs and data loss when performing
> mount/umount then remount the device with jffs2 format.
> This patch is tested on Lager board at Linux uptream v4.10-rc5.
> Please consider the patch for Renesas-soc Gen2

Please send patches inline.

> From 5513c6a02c911fcf9f99d5188fa46256aa1e41b4 Mon Sep 17 00:00:00 2001
> From: Dong <cv-dong@xxxxxxxxxxx>
> Date: Fri, 27 Jan 2017 16:29:18 +0900
> Subject: [PATCH] spi: rspi: fix the bug related to mount/remount jffs2
>
> 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@xxxxxxxxxxx>
> ---
>  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;

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
>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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
--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html