From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from galois.linutronix.de ([2001:470:1f0b:1c35:abcd:42:0:1])
 by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux))
 id 1Rz7Rg-00045p-8j
 for linux-mtd@lists.infradead.org; Sun, 19 Feb 2012 14:08:57 +0000
Message-ID: <4F41026C.6060203@linutronix.de>
Date: Sun, 19 Feb 2012 15:08:44 +0100
From: Richard Weinberger <rw@linutronix.de>
MIME-Version: 1.0
To: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Subject: Re: [RFC][PATCH 7/7] MTD: UBI: wire up checkpointing
References: <1329250006-22944-1-git-send-email-rw@linutronix.de>
 <1329250006-22944-8-git-send-email-rw@linutronix.de>
 <20120219155741.4c2f0a02@pixies.home.jungo.com>
In-Reply-To: <20120219155741.4c2f0a02@pixies.home.jungo.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: tglx@linutronix.de, tim.bird@am.sony.com, linux-mtd@lists.infradead.org,
 linux-kernel@vger.kernel.org, dedekind1@gmail.com
List-Id: Linux MTD discussion mailing list <linux-mtd.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-mtd/>
List-Post: <mailto:linux-mtd@lists.infradead.org>
List-Help: <mailto:linux-mtd-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=subscribe>

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