4.4-stable review patch. If anyone has any objections, please let me know.
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From: Richard Weinberger richard@nod.at
commit b5094b7f135be34630e3ea8a98fa215715d0f29d upstream.
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@vger.kernel.org Signed-off-by: Richard Weinberger richard@nod.at Acked-by: Boris Brezillon boris.brezillon@bootlin.com Acked-by: Artem Bityutskiy dedekind1@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mtd/ubi/build.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -889,6 +889,17 @@ int ubi_attach_mtd_dev(struct mtd_info * 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++)