Re: [PATCH v20 02/12] Add infrastructure for copy offload in block and request layer.

From: Christoph Hellwig
Date: Sat Jun 01 2024 - 01:57:54 EST


On Wed, May 29, 2024 at 04:48:18PM +0900, Damien Le Moal wrote:
> > Yes, in this case copy won't work, as both src and dst bio reach driver
> > as part of separate requests.
> > We will add this as part of documentation.
>
> So that means that 2 major SAS HBAs which set this flag (megaraid and mpt3sas)
> will not get support for copy offload ? Not ideal, by far.

We really need to ignore the normerges flag for this.
As should we for the precedence in the discard merging.

And the drivers need to stop setting this flag as they have no business
to, but that's a separate discussion (and the flag can still be set
manually).