From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934238Ab2JKBZ0 (ORCPT ); Wed, 10 Oct 2012 21:25:26 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:57104 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933959Ab2JKBZS (ORCPT ); Wed, 10 Oct 2012 21:25:18 -0400 X-Sasl-enc: C7QGzGxBqT4FPa2FVUqcmLAQ9HiAT3kBNC8pYOMD8OjL 1349918711 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Michal Hocko , Hillf Danton , Mel Gorman , KAMEZAWA Hiroyuki , Andrea Arcangeli , David Rientjes , Johannes Weiner , Andrew Morton , Linus Torvalds Subject: [ 075/120] hugetlb: do not use vma_hugecache_offset() for vma_prio_tree_foreach Date: Thu, 11 Oct 2012 10:00:27 +0900 Message-Id: <20121011005840.036284747@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.rc0.18.gf84667d In-Reply-To: <20121011005825.364610894@linuxfoundation.org> References: <20121011005825.364610894@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Hocko commit 36e4f20af833d1ce196e6a4ade05dc26c44652d1 upstream. Commit 0c176d52b0b2 ("mm: hugetlb: fix pgoff computation when unmapping page from vma") fixed pgoff calculation but it has replaced it by vma_hugecache_offset() which is not approapriate for offsets used for vma_prio_tree_foreach() because that one expects index in page units rather than in huge_page_shift. Johannes said: : The resulting index may not be too big, but it can be too small: assume : hpage size of 2M and the address to unmap to be 0x200000. This is regular : page index 512 and hpage index 1. If you have a VMA that maps the file : only starting at the second huge page, that VMAs vm_pgoff will be 512 but : you ask for offset 1 and miss it even though it does map the page of : interest. hugetlb_cow() will try to unmap, miss the vma, and retry the : cow until the allocation succeeds or the skipped vma(s) go away. Signed-off-by: Michal Hocko Acked-by: Hillf Danton Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Cc: Andrea Arcangeli Cc: David Rientjes Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2431,7 +2431,8 @@ static int unmap_ref_private(struct mm_s * from page cache lookup which is in HPAGE_SIZE units. */ address = address & huge_page_mask(h); - pgoff = vma_hugecache_offset(h, vma, address); + pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + + vma->vm_pgoff; mapping = vma->vm_file->f_dentry->d_inode->i_mapping; /*