[PATCHv2] nvmet: lift blocksize restriction to 64k

[Hannes Reinecke]

On 2/20/26 17:45, Christoph Hellwig wrote:
> On Fri, Feb 20, 2026 at 05:42:25PM +0100, Hannes Reinecke wrote:
>> On 2/20/26 16:32, Christoph Hellwig wrote:
>>> On Fri, Feb 20, 2026 at 04:12:59PM +0100, Hannes Reinecke wrote:
>>>> With commit 47dd67532303 ("block/bdev: lift block size restrictions to 64k")
>>>> we can now support up to 64k block sizes, so lift the restriction on 4k for
>>>> file-backed namespaces.
>>>
>>> Still not sure this is a great idea by default.  Yes, modern Linux supports
>>> 64k sector sizes, but even then just for a few file systems.  And this
>>> changes existing setups, which will now break when upgrading the kernel.
>>>
>> How so? There cannot be any existing nvmet setup with an LBS backing
>> device, as the device will be rejected when trying to setup the target.
>> Which breakage do you see here?
> 
> There can be a setup with a large i_blkbits that we limit to 4k
> export LBA size right now, and with your patch it will be exposed
> as something larger.
> 
True.
Hmm. Okay, I'll work on something.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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