Commit 0c176d52 authored Jan 10, 2012 by Hillf Danton Committed by Linus Torvalds Jan 10, 2012

mm: hugetlb: fix pgoff computation when unmapping page from vma



The computation for pgoff is incorrect, at least with

	(vma->vm_pgoff >> PAGE_SHIFT)

involved.  It is fixed with the available method if HPAGE_SIZE is
concerned in page cache lookup.

[akpm@linux-foundation.org: use vma_hugecache_offset() directly, per Michal]
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 86cfd3a4

mm/hugetlb.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -2315,8 +2315,7 @@ static int unmap_ref_private(struct mm_struct mm, struct vm_area_struct vma,
		* from page cache lookup which is in HPAGE_SIZE units.
		*/
		address = address & huge_page_mask(h);
		pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
		+ (vma->vm_pgoff >> PAGE_SHIFT);
		pgoff = vma_hugecache_offset(h, vma, address);
		mapping = (struct address_space *)page_private(page);

		/*

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