[PATCH] calculation of pgoff in do_linear_fault() uses mixed units

[dcn@sgi.com (Dean Nelson)]

The calculation of pgoff in do_linear_fault() should use PAGE_SHIFT and not
PAGE_CACHE_SHIFT since vma->vm_pgoff is in units of PAGE_SIZE and not
PAGE_CACHE_SIZE. At the moment linux/pagemap.h has PAGE_CACHE_SHIFT defined
as PAGE_SHIFT, but should that ever change this calculation would break.

Signed-off-by: Dean Nelson <dcn@sgi.com>


Index: linux-2.6/mm/memory.c
===================================================================
--- linux-2.6.orig/mm/memory.c	2007-08-14 06:42:18.322378070 -0500
+++ linux-2.6/mm/memory.c	2007-08-15 12:30:51.621604739 -0500
@@ -2465,7 +2465,7 @@
 		int write_access, pte_t orig_pte)
 {
 	pgoff_t pgoff = (((address & PAGE_MASK)
-			- vma->vm_start) >> PAGE_CACHE_SHIFT) + vma->vm_pgoff;
+			- vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
 	unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
 
 	return __do_fault(mm, vma, address, page_table, pmd, pgoff,
-
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