[RFC PATCH 2/2] mtd: ubi: wl: avoid erasing a PEB which is empty

[Sebastian Andrzej Siewior]

On 11/24/2015 09:39 AM, Richard Weinberger wrote:
>>>> +	} else {
>>>> +		err = do_sync_erase(ubi, e2, vol_id, lnum, torture);
>>>> +		if (err) {
>>>> +			wl_entry_destroy(ubi, e2);
>>>
>>> Why that? The erase_worker will free e2 if it encounters
>>> a fatal error and gives up this PEB. You're introducing a double free.
>>
>> Hmmm. That is real bad error handling you have there. So you invoke
>> do_sync_erase(), the kmalloc() fails and how exactly you free e2 here?
> 
> Why do you want to free e2? We free an erase entry only if we give
> it up. wear leveling entries are allocated at init time and destroyed
> when you detach UBI.

The reference to it in the RB-tree (free) was removed. Is there another
reference to it?

> Thanks,
> //richard
> 

Sebastian