[PATCH 5/5] ubi: Allow to use read-only UBI volume with not enough PEBs

[Richard Weinberger]

Pali,

Am 25.07.2017 um 16:27 schrieb Pali Rohár:
>> I fear this is not correct, it will disable a legit self-check of UBI volumes.
>> If the read-only volume is corrupted/truncated and you miss PEBs, this
>> check will no longer
>> trigger.
>>
>> Especially when dealing with nanddumps, truncation is a common problem.
> 
> Any idea how to fix it? Or how to handle read-only images which are
> marked for auto-resize?

I'd vote for rejecting images that have auto-resize set when the MTD is read-only.
In fact, using UBI on top of a read-only MTD is very uncommon and not recommended (for NAND).
The auto-resize flag should be also only set when you just have created it using mkfs.ubifs.
Why would you inspect such an image with the kernel UBIFS unless you're hunting down a bug
in mkfs.ubifs?

Thanks,
//richard