[PATCH] mm: page fault handlers tidyup

Impose a little more consistency on the page fault handlers do_wp_page,
do_swap_page, do_anonymous_page, do_no_page, do_file_page: why not pass their
arguments in the same order, called the same names?

break_cow is all very well, but what it did was inlined elsewhere: easier to
compare if it's brought back into do_wp_page.

do_file_page's fallback to do_no_page dates from a time when we were testing
pte_file by using it wherever possible: currently it's peculiar to nonlinear
vmas, so just check that.  BUG_ON if not?  Better not, it's probably page
table corruption, so just show the pte: hmm, there's a pte_ERROR macro, let's
use that for do_wp_page's invalid pfn too.

Hah!  Someone in the ppc64 world noticed pte_ERROR was unused so removed it:
restored (and say "pud" not "pmd" in its pud_ERROR).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 1c31b2fd2ca5..8aa344e88489 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1520,7 +1520,7 @@ repeat:
                         page_cache_release(page);
                         return err;
                 }
-        } else {
+        } else if (vma->vm_flags & VM_NONLINEAR) {
                 /* No page was found just because we can't read it in now (being
                  * here implies nonblock != 0), but the page may exist, so set
                  * the PTE to fault it in later. */