On Wed, Nov 16, 2016 at 12:50:21AM +0300, Kirill A. Shutemov wrote: > On Fri, Nov 04, 2016 at 05:24:57AM +0100, Jan Kara wrote: > > Currently we have two different structures for passing fault information > > around - struct vm_fault and struct fault_env. DAX will need more > > information in struct vm_fault to handle its faults so the content of > > that structure would become event closer to fault_env. Furthermore it > > would need to generate struct fault_env to be able to call some of the > > generic functions. So at this point I don't think there's much use in > > keeping these two structures separate. Just embed into struct vm_fault > > all that is needed to use it for both purposes. > > > > Signed-off-by: Jan Kara <jack@xxxxxxx> > > I'm not necessary dislike this, but I remember Peter had objections before > when I proposed something similar. > > Peter? My objection was that it would be a layering violation. The 'filesystem' shouldn't know about page-tables, all it should do is return a page matching a specific offset. So fault_env manages the core vm parts and has the page-table bits in, vm_fault manages the filesystem interface and gets us a page given an offset. Now, I'm entirely out of touch wrt DAX, so I've not idea what that needs/wants. > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index a92c8d73aeaf..657eb69eb87e 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -292,10 +292,16 @@ extern pgprot_t protection_map[16]; > > * pgoff should be used in favour of virtual_address, if possible. > > */ > > struct vm_fault { > > + struct vm_area_struct *vma; /* Target VMA */ > > unsigned int flags; /* FAULT_FLAG_xxx flags */ > > gfp_t gfp_mask; /* gfp mask to be used for allocations */ > > pgoff_t pgoff; /* Logical page offset based on vma */ > > + unsigned long address; /* Faulting virtual address */ > > + void __user *virtual_address; /* Faulting virtual address masked by > > + * PAGE_MASK */ > > + pmd_t *pmd; /* Pointer to pmd entry matching > > + * the 'address' > > + */ > > > > struct page *cow_page; /* Handler may choose to COW */ > > struct page *page; /* ->fault handlers should return a Egads, horrific commenting style that :-) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html