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 for linux-mtd@lists.infradead.org; Mon, 09 Nov 2015 20:50:04 +0000
Subject: Re: Hang on reboot in nand_get_device()
To: "Andrew E. Mileski" <andrewm@isoar.ca>, Brian Norris
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From: Scott Branden <sbranden@broadcom.com>
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Date: Mon, 9 Nov 2015 12:49:41 -0800
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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