[PATCH 3/3] UBI: Fix possible deadlock in erase_worker()

[Richard Weinberger]

Am 26.09.2014 12:40, schrieb Artem Bityutskiy:
> On Mon, 2014-09-22 at 10:45 +0200, Richard Weinberger wrote:
>> If sync_erase() fails with EINTR, ENOMEM, EAGAIN or
>> EBUSY erase_worker() re-schedules the failed work.
>> This will lead to a deadlock because erase_worker() is called
>> with work_sem held in read mode. And schedule_erase() will take
>> this lock again.
>>
>> Signed-off-by: Richard Weinberger <richard at nod.at>
> 
> Did you manage to test it?
> 
> Why no -stable this time? Not that important, or just something
> theoretical and you never actually hit this bug?

It is something theoretical, I was only able to trigger it by injecting
ENOMEM by hand.

Thanks,
//richard