Hang on reboot in nand_get_device()

[Scott Branden]

On 15-11-09 11:56 AM, Andrew E. Mileski wrote:
> On 2015-11-09 14:46, Brian Norris wrote:
>>
>> No, and that's the point of "getting" the device, without actually
>> releasing it. (Andrew's suggestion is essentially a
>> nand_release_device().) We don't want any other process picking up any
>> I/O at this point. I suppose there really is no way to begin any new
>> I/O, but it does seem possible for the last operation to still be in
>> flight, at least according to Scott's reports.
>
> That right there. is the very reason I questioned whether my approach
> was sufficient.

Yes, the last operation can still be in flight - there are async cleanup 
threads running in the UBI/UBIFS layers which recreated this problem.
>
> ~~Andrew E. Mileski