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Subject: Re: [PATCH] mtd: fix size in mtd_info_user to support 64-bit
From:   Rob Landley <rob@landley.net>
To:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Miaohe Lin <linmiaohe@huawei.com>
Cc:     richard@nod.at, vigneshr@ti.com, David.Woodhouse@intel.com,
        Artem.Bityutskiy@nokia.com, ext-adrian.hunter@nokia.com,
        linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
        linfeilong@huawei.com
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Date:   Thu, 22 Jul 2021 03:47:42 -0500
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On 7/16/21 8:34 AM, Rob Landley wrote:
>> The only way is to create a second UAPI.
> 
> Twelve years ago a patch was submitted to add a 64 bit MTD api:
> 
>   https://lwn.net/Articles/326418/
> 
> But for some reason they only merged 64 bit erase:
> 
>   https://github.com/torvalds/linux/commit/0dc54e9f33e2
> 
> But NOT the rest of the 64 bit mtd API in the same patch. I've never understood why.

That said, the workaround is to use the info api for erase size and use
lseek(SEEK_END) on the device to get the length.

Rob