Re: [PATCH 3/7] fsdax: Copy data before write

[Ruan Shiyang <ruansy.fnst@xxxxxxxxxxxxxx>]

On 2021/2/8 下午11:14, Christoph Hellwig wrote:
> >   	switch (iomap.type) {
> >   	case IOMAP_MAPPED:
> > +cow:
> >   		if (iomap.flags & IOMAP_F_NEW) {
> >   			count_vm_event(PGMAJFAULT);
> >   			count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
> >   			major = VM_FAULT_MAJOR;
> >   		}
> >   		error = dax_iomap_direct_access(&iomap, pos, PAGE_SIZE,
> > -						NULL, &pfn);
> > +						&kaddr, &pfn);
>
> Any chance you could look into factoring out this code into a helper
> to avoid the goto magic, which is a little too convoluted?
>
> >   	switch (iomap.type) {
> >   	case IOMAP_MAPPED:
> > +cow:
> >   		error = dax_iomap_direct_access(&iomap, pos, PMD_SIZE,
> > -						NULL, &pfn);
> > +						&kaddr, &pfn);
> >   		if (error < 0)
> >   			goto finish_iomap;
> >   
> >   		entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn,
> >   						DAX_PMD, write && !sync);
> >   
> > +		if (srcmap.type != IOMAP_HOLE) {
>
> Same here.

Thanks for suggestion.  I'll try it.


--
Thanks,
Ruan Shiyang.
>