[PATCH v2] cmd: mtd: check if a block has to be skipped or erased

[Mikhail Kshevetskiy]

What patch will be finally applied? I am preparing a patch that will 
fix Dario Binacchi issues with non-BBT bad block.

>From my point of view this patch have wrong lines in 'Changes in v2'
- Do not continue to erase if scrub option is enabled and a bad block
  was found but return from the function.

Issues of original Dario Binacchi patch:

Non-BBT registered bad block will break 'mtd erase'.

In this case
 * mtd_erase() will returns with -EIO
 * erasing will be stopped due to error
 * 'mtd erase' returns CMD_RET_SUCCESS as -EIO is expected result

Fix this by:
  a) return back -EIO check after mtd_erase()
  b) simulate bad block behavior and jump to mtd_erase() results
     check in the case of BBT registered bad block.



On 24.10.2022 12:35, Dario Binacchi wrote:
> [External email]
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> From: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
>
> As reported by patch [1], the `mtd erase' command should not erase bad
> blocks.
> To force bad block erasing you have to use the `mtd erase.dontskipbad'
> command.
>
> This patch tries to fix the same issue without modifying code taken
> from the linux kernel, in order to make further upgrades easier.
>
> [1] https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F20221006031501.110290-2-mikhail.kshevetskiy%40iopsys.eu%2F&data=05%7C01%7Cmikhail.kshevetskiy%40iopsys.eu%7C0b0682eb6b3444494b7b08dab5a31581%7C7ff78d652de440f586750569e5c7a65d%7C0%7C0%7C638022009312464027%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=7Mx%2BHk7KIxaUitavWhTRwtfDL%2FaaOYA9o02oWFiFlw0%3D&reserved=0
> Suggested-by: Michael Trimarchi <michael at amarulasolutions.com>
> Co-developed-by: Michael Trimarchi <michael at amarulasolutions.com>
> Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
> Co-developed-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>
> Signed-off-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>
> Tested-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
>
> ---
>
> Changes in v2:
> - Change the commit author
> - Do not continue to erase if scrub option is enabled and a bad block
>   was found but return from the function.
> - Update the patch tags.
>
>  cmd/mtd.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/cmd/mtd.c b/cmd/mtd.c
> index ad5cc9827d55..a314745e95e1 100644
> --- a/cmd/mtd.c
> +++ b/cmd/mtd.c
> @@ -434,11 +434,24 @@ static int do_mtd_erase(struct cmd_tbl *cmdtp, int flag, int argc,
>         erase_op.mtd = mtd;
>         erase_op.addr = off;
>         erase_op.len = mtd->erasesize;
> -       erase_op.scrub = scrub;
>
>         while (len) {
> -               ret = mtd_erase(mtd, &erase_op);
> +               if (!scrub) {
> +                       ret = mtd_block_isbad(mtd, erase_op.addr);
> +                       if (ret < 0) {
> +                               printf("Failed to get bad block at 0x%08llx\n",
> +                                      erase_op.addr);
> +                               ret = CMD_RET_FAILURE;
> +                               goto out_put_mtd;
> +                       } else if (ret > 0) {
> +                               /* simulate bad block behavior */
> +                               ret = -EIO;
> +                               goto skip_block_erasing;
> +                       }
> +               }
>
> +               ret = mtd_erase(mtd, &erase_op);
> +skip_block_erasing:
>                 if (ret) {
>                         /* Abort if its not a bad block error */
>                         if (ret != -EIO)
> --
> 2.32.0
>