Re: [PATCH] [RFC] UBI: Implement Fastmap support

From: Artem Bityutskiy
Date: Tue May 22 2012 - 09:39:47 EST


Uhh, too many helpers.

On Mon, 2012-05-21 at 16:01 +0200, Richard Weinberger wrote:
> /**
> - * ubi_attach - attach an MTD device.
> - * @ubi: UBI device descriptor
> + * scan_fastmap - attach MTD device using fastmap.
> + * @ubi: UBI device description object
> *
> - * This function returns zero in case of success and a negative error code in
> - * case of failure.
> + * This function attaches a MTD device using a fastmap and returns complete
> + * information about it in form of a "struct ubi_attach_info" object. In case
> + * of failure, an error code is returned.
> */
> -int ubi_attach(struct ubi_device *ubi)
> +static struct ubi_attach_info *scan_fastmap(struct ubi_device *ubi)
> +{
> + int fm_start;
> +
> + fm_start = ubi_find_fastmap(ubi);
> + if (fm_start < 0)
> + return ERR_PTR(-ENOENT);
> +
> + return ubi_read_fastmap(ubi, fm_start);
> +}

This helper which does not do anything useful should not exist - just
teach 'ubi_read_fastmap()' to return 1 if the fastmap is not found, and
< 0 on error, and 0 on success. No one in attach.c should be interested
in fm_start. So this helper should die. See below as well.

> +
> +static int do_attach(struct ubi_device *ubi, bool fullscan)
> {
> int err;
> struct ubi_attach_info *ai;
>
> - ai = scan_all(ubi);
> + if (fullscan)
> + ai = scan_all(ubi);
> + else
> + ai = scan_fastmap(ubi);
> +
> if (IS_ERR(ai))
> return PTR_ERR(ai);
>
> @@ -1256,6 +1277,31 @@ out_ai:
> }

Another useless helper function, should die, see below.

>
> /**
> + * ubi_attach - attach an MTD device.
> + * @ubi: UBI device descriptor
> + *
> + * This function returns zero in case of success and a negative error code in
> + * case of failure.
> + */
> +int ubi_attach(struct ubi_device *ubi)
> +{
> + int err;
> +
> + err = do_attach(ubi, false);
> + if (err) {
> + if (err != -ENOENT)
> + ubi_err("Attach by fastmap failed! " \
> + "Falling back to attach by scanning. " \
> + "error = %i\n", err);
> +
> + ubi->attached_by_scanning = true;
> + err = do_attach(ubi, true);
> + }
> +
> + return err;
> +}

Just add this code to this function:

err = ubi_read_fastmap();
if (err < 0)
return err;
if (err == 2)
return scan_all();

... rest of the common nitializations (EBA, WL)...

return err;

--
Best Regards,
Artem Bityutskiy

Attachment: signature.asc
Description: This is a digitally signed message part