filemap_nopage — read in file data for page fault handling
struct page * filemap_nopage
(struct vm_area_struct * area, unsigned long address, int * type);
the applicable vm_area
target address to read in
returned with VM_FAULT_{MINOR,MAJOR} if not NULL
filemap_nopage is invoked via the vma operations vector for a mapped memory region to read in file data during a page fault.
The goto's are kind of ugly, but this streamlines the normal case of having it in the page cache, and handles the special cases reasonably without having a lot of duplicated code.