linux-kernel - Re: [PATCH] UBI: fastmap: fix backward compatibility with image

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Date:	Fri, 27 Sep 2013 16:53:50 +0200
From:	Richard Genoud <richard.genoud@...il.com>
To:	Richard Weinberger <richard@....at>
Cc:	Artem Bityutskiy <dedekind1@...il.com>,
	David Woodhouse <dwmw2@...radead.org>,
	linux-mtd <linux-mtd@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] UBI: fastmap: fix backward compatibility with image_seq

2013/9/27 Richard Weinberger <richard@....at>:
> Am 27.09.2013 15:16, schrieb Richard Genoud:
>> 2013/9/27 Richard Weinberger <richard@....at>:
>>> Am 27.09.2013 14:51, schrieb Richard Genoud:
>>>> Some old UBI implementations (e.g. U-Boot) have not implemented the image
>>>> sequence feature.
>>>> So, when erase blocks are written, the image sequence in the ec header
>>>> is lost (set to zero).
>>>> UBI scan_all() takes this case into account (commits
>>>> 32bc4820287a1a03982979515949e8ea56eac641 and
>>>> 2eadaad67b2b6bd132eda105128d2d466298b8e3)
>>>>
>>>> But fastmap scan functions (ubi_scan_fastmap() and scan_pool()) didn't.
>>>>
>>>> This patch fixes the issue.
>>>>
>>>> Signed-off-by: Richard Genoud <richard.genoud@...il.com>
>>>> ---
>>>
>>> W00t! Good catch!
>>>
>>> Acked-by: Richard Weinberger <richard@....at>
>> Thanks :)
>>
>>
>> There's still an error when the image sequence is bad:
>> [   35.632812] UBI error: scan_pool: bad image seq: 0x0, expected: 0x6e452f03
>> [   35.640625] UBI error: ubi_scan_fastmap: Attach by fastmap failed,
>> doing a full scan!
>> [   35.648437] kmem_cache_destroy ubi_ainf_peb_slab: Slab cache still
>> has objects  <- the destroy_ai in line 1415
>
> *grrr*, the problem here is that not all allocations which are done via
> kmem_cache_alloc(ai->aeb_slab_cache, ...) got kfree()'d.
>
> Thanks,
> //richard

My first guess is in fastmap.c, function scan_pool(), in the loop "for
(i = 0; i < pool_size; i++)"
there's some "add_aeb()" and "new_aeb = kmem_cache_alloc()"
And on error, I don't see a loop backward to free those ones.


Richard.
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