Re: [RFC][PATCH 7/7] MTD: UBI: wire up checkpointing

Richard Weinberger
2012-02-19T14:08:57Z

Am 19.02.2012 14:57, schrieb Shmulik Ladkani:
> On Tue, 14 Feb 2012 21:06:46 +0100 Richard Weinberger<rw@linutronix.de> wrote:
>> +#ifdef CONFIG_MTD_UBI_CHECKPOINT
>> +static int attach_by_checkpointing(struct ubi_device *ubi)
>> +{
>> + int cp_start, err;
>> + struct ubi_scan_info *si;
>> +
>> + cp_start = ubi_find_checkpoint(ubi);
>> + if (cp_start< 0)
>> + return -ENOENT;
>> +
>> + si = ubi_read_checkpoint(ubi, cp_start);
>> + if (IS_ERR(si))
>> + return PTR_ERR(si);
>> +
>> + ubi->bad_peb_count = 0;
>> + ubi->good_peb_count = ubi->peb_count;
>
> Zero reported bad PEBs when checkpointing.
> Seems that checkpointing does not remember number/location of bad PEBs.

Currently checkpointing cares only about used and free PEBs.
Bad PEBs are no longer visible to UBI after recovering from a checkpoint.

> Are we fine with that?

This patch is a RFC. :-)

>> +#ifdef CONFIG_MTD_UBI_CHECKPOINT
>> + err = attach_by_checkpointing(ubi);
>> +
>> + if (err) {
>> + if (err != -ENOENT)
>> + ubi_msg("falling back to attach by scanning mode!\n");
>> +
>> + err = attach_by_scanning(ubi);
>> + }
>
> Code does not fit error message.
> Message states "falling back to scanning" only if "err != -ENOENT".
> However code calls 'attach_by_scanning' regardless 'err'.
> Was it your intention?

Yes.
If recovering from a checkpoint fails the corresponding code prints
a human readable error message in any case.

Thanks,
//richard