RE: [EXT] Re: [PATCHv11 00/10] block write streams with nvme fdp

[Pierre Labat <plabat@micron.com>]

Thanks Keith for the clarification.
If I got it right, that will be decided later by the filesystem maintainers if they went to convert the write hint assigned to a file via fcntl() into a write_stream that is the one used by the block drivers (for FDP for nvme).
Regards,
Pierre

> -----Original Message-----
> From: Keith Busch <kbusch@kernel.org>
> Sent: Monday, December 9, 2024 9:25 AM
> To: Pierre Labat <plabat@micron.com>
> Cc: Christoph Hellwig <hch@lst.de>; Keith Busch <kbusch@meta.com>;
> axboe@kernel.dk; linux-block@vger.kernel.org; linux-
> nvme@lists.infradead.org; linux-fsdevel@vger.kernel.org; io-
> uring@vger.kernel.org; sagi@grimberg.me; asml.silence@gmail.com
> Subject: Re: [EXT] Re: [PATCHv11 00/10] block write streams with nvme fdp
> 
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> 
> On Mon, Dec 09, 2024 at 05:14:16PM +0000, Pierre Labat wrote:
> > I was under the impression that passing write hints via fcntl() on any
> > legacy filesystem stays. The hint is attached to the inode, and the fs
> > simply picks it up from there when sending it down with write related
> > to that inode.
> > Aka per file write hint.
> >
> > I am right?
> 
> Nothing is changing with respect to those write hints as a result of this series,
> if that's what you mean. The driver hadn't been checking the write hint before,
> and this patch set continues that pre-existing behavior. For this series, the
> driver utilizes a new field:
> "write_stream".
> 
> Mapping the inode write hint to an FDP stream for other filesystems remains
> an open topic to follow on later.