On Sat, 3 Mar 2018 11:45:54 +0100
Richard Weinberger <richard@xxxxxx> wrote:
> While UBI and UBIFS seem to work at first sight with MLC NAND, you will
> most likely lose all your data upon a power-cut or due to read/write
> disturb.
> In order to protect users from bad surprises, refuse to attach to MLC
> NAND.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Richard Weinberger <richard@xxxxxx>
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> ---
> drivers/mtd/ubi/build.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
> index e941395de3ae..753494e042d5 100644
> --- a/drivers/mtd/ubi/build.c
> +++ b/drivers/mtd/ubi/build.c
> @@ -854,6 +854,17 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
> return -EINVAL;
> }
>
> + /*
> + * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
> + * MLC NAND is different and needs special care, otherwise UBI or UBIFS
> + * will die soon and you will lose all your data.
> + */
> + if (mtd->type == MTD_MLCNANDFLASH) {
> + pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
> + mtd->index);
> + return -EINVAL;
> + }
> +
> if (ubi_num == UBI_DEV_NUM_AUTO) {
> /* Search for an empty slot in the @ubi_devices array */
> for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
--
Boris Brezillon, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com