[PATCH] hugetlb: fix absurd HugePages_Rsvd

Hugh Dickins · Linus Torvalds · commit ebed4bfc8da8 · 2006-10-28T11:30:53.000-07:00
If you truncated an mmap'ed hugetlbfs file, then faulted on the truncated
area, /proc/meminfo's HugePages_Rsvd wrapped hugely "negative".  Reinstate my
preliminary i_size check before attempting to allocate the page (though this
only fixes the most obvious case: more work will be needed here).

Signed-off-by: Hugh Dickins &lt;hugh@veritas.com&gt;
Cc: Adam Litke &lt;agl@us.ibm.com&gt;
Cc: David Gibson &lt;david@gibson.dropbear.id.au&gt;
Cc: "Chen, Kenneth W" &lt;kenneth.w.chen@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
@@ -478,6 +478,9 @@ int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 retry:
 	page = find_lock_page(mapping, idx);
 	if (!page) {
+		size = i_size_read(mapping->host) >> HPAGE_SHIFT;
+		if (idx >= size)
+			goto out;
 		if (hugetlb_get_quota(mapping))
 			goto out;
 		page = alloc_huge_page(vma, address);
