[PATCH RESEND] mtd: ubi: block: Fix error for write access

[Richard Weinberger]

Am Freitag, 2. März 2018, 12:16:18 CET schrieb Romain Izard:
> When opening a device with write access, ubiblock_open returns an error
> code. Currently, this error code is -EPERM, but this is not the right
> value.
> 
> The open function for other block devices returns -EROFS when opening
> read-only devices with FMODE_WRITE set. When used with dm-verity, the
> veritysetup userspace tool is expecting EROFS, and refuses to use the
> ubiblock device.
> 
> Use -EROFS for ubiblock as well. As a result, veritysetup accepts the
> ubiblock device as valid.
> 
> Fixes: 9d54c8a33eec (UBI: R/O block driver on top of UBI volumes)
> Signed-off-by: Romain Izard <romain.izard.pro at gmail.com>
> ---
>  drivers/mtd/ubi/block.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
> index b210fdb31c98..4533423cf2aa 100644
> --- a/drivers/mtd/ubi/block.c
> +++ b/drivers/mtd/ubi/block.c
> @@ -242,7 +242,7 @@ static int ubiblock_open(struct block_device *bdev,
> fmode_t mode) * in any case.
>  	 */
>  	if (mode & FMODE_WRITE) {
> -		ret = -EPERM;
> +		ret = -EROFS;

Queued for -next.

Thanks,
//richard