rmap: drop support of non-linear mappings

We don't create non-linear mappings anymore.  Let's drop code which
handles them in rmap.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 32 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 344cdf692fc8..6e284bcca8bb 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -179,37 +179,6 @@ out:
 }
 
 /*
- * Congratulations to trinity for discovering this bug.
- * mm/fremap.c's remap_file_pages() accepts any range within a single vma to
- * convert that vma to VM_NONLINEAR; and generic_file_remap_pages() will then
- * replace the specified range by file ptes throughout (maybe populated after).
- * If page migration finds a page within that range, while it's still located
- * by vma_interval_tree rather than lost to i_mmap_nonlinear list, no problem:
- * zap_pte() clears the temporary migration entry before mmap_sem is dropped.
- * But if the migrating page is in a part of the vma outside the range to be
- * remapped, then it will not be cleared, and remove_migration_ptes() needs to
- * deal with it.  Fortunately, this part of the vma is of course still linear,
- * so we just need to use linear location on the nonlinear list.
- */
-static int remove_linear_migration_ptes_from_nonlinear(struct page *page,
-		struct address_space *mapping, void *arg)
-{
-	struct vm_area_struct *vma;
-	/* hugetlbfs does not support remap_pages, so no huge pgoff worries */
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
-	unsigned long addr;
-
-	list_for_each_entry(vma,
-		&mapping->i_mmap_nonlinear, shared.nonlinear) {
-
-		addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
-		if (addr >= vma->vm_start && addr < vma->vm_end)
-			remove_migration_pte(page, vma, addr, arg);
-	}
-	return SWAP_AGAIN;
-}
-
-/*
  * Get rid of all migration entries and replace them by
  * references to the indicated page.
  */
@@ -218,7 +187,6 @@ static void remove_migration_ptes(struct page *old, struct page *new)
 	struct rmap_walk_control rwc = {
 		.rmap_one = remove_migration_pte,
 		.arg = old,
-		.file_nonlinear = remove_linear_migration_ptes_from_nonlinear,
 	};
 
 	rmap_walk(new, &rwc);