Hi Christoph,
> > if (battr->mapping)
> > - of->file->f_mapping = battr->mapping;
> > + of->file->f_mapping = battr->mapping();
>
> I think get_mapping() is a better name now. That being said this
> whole programming model looks a little weird.
I would have to lean on Daniel and Dan here as they might have more
context than I do, especially since in the PCI world we are only
consumers of this new API. The related patches are:
commit 3234ac664a87 ("/dev/mem: Revoke mappings when a driver claims the region")
commit 636b21b50152 ("PCI: Revoke mappings like devmem")
> Also, does this patch imply the mapping field of the sysfs bin
> attributes wasn't used before at all?
No, everything worked as intended, thankfully. Changes here are meant
to help us transition to use static sysfs objects when we add various
PCI-related attributes a particular device. This in turn will allow us
to remove the need for late_initcall() in the drivers/pci/pci-sysfs.c,
and thus fix the race condition people noticed on some platforms when
sysfs objects are being added while PCI sub-system and devices are
initialised.
More details are captured in the following conversations:
https://lore.kernel.org/linux-pci/20200716110423.xtfyb3n6tn5ixedh@pali/
https://lore.kernel.org/linux-pci/20210527205845.GA1421476@bjorn-Precision-5520/
https://lore.kernel.org/linux-pci/20210313215747.GA2394467@bjorn-Precision-5520/
Dan's original patch:
https://lore.kernel.org/linux-pci/CAPcyv4i0y_4cMGEpNVShLUyUk3nyWH203Ry3S87BqnDJE0Rmxg@xxxxxxxxxxxxxx/
Krzysztof
