From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752223AbdJSXAs (ORCPT ); Thu, 19 Oct 2017 19:00:48 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:32709 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003AbdJSXAr (ORCPT ); Thu, 19 Oct 2017 19:00:47 -0400 From: Mike Kravetz To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Naoya Horiguchi , Michal Hocko , Aneesh Kumar , Anshuman Khandual , Andrew Morton , Mike Kravetz , stable@vger.kernel.org Subject: [PATCH 1/1] mm:hugetlbfs: Fix hwpoison reserve accounting Date: Thu, 19 Oct 2017 16:00:07 -0700 Message-Id: <20171019230007.17043-2-mike.kravetz@oracle.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20171019230007.17043-1-mike.kravetz@oracle.com> References: <20171019230007.17043-1-mike.kravetz@oracle.com> X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Calling madvise(MADV_HWPOISON) on a hugetlbfs page will result in bad (negative) reserved huge page counts. This may not happen immediately, but may happen later when the underlying file is removed or filesystem unmounted. For example: AnonHugePages: 0 kB ShmemHugePages: 0 kB HugePages_Total: 1 HugePages_Free: 0 HugePages_Rsvd: 18446744073709551615 HugePages_Surp: 0 Hugepagesize: 2048 kB In routine hugetlbfs_error_remove_page(), hugetlb_fix_reserve_counts is called after remove_huge_page. hugetlb_fix_reserve_counts is designed to only be called/used only if a failure is returned from hugetlb_unreserve_pages. Therefore, call hugetlb_unreserve_pages as required and only call hugetlb_fix_reserve_counts in the unlikely event that hugetlb_unreserve_pages returns an error. Fixes: 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error") Cc: Naoya Horiguchi Cc: Michal Hocko Cc: Aneesh Kumar Cc: Anshuman Khandual Cc: Andrew Morton Cc: Signed-off-by: Mike Kravetz --- fs/hugetlbfs/inode.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 59073e9f01a4..ed113ea17aff 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -842,9 +842,12 @@ static int hugetlbfs_error_remove_page(struct address_space *mapping, struct page *page) { struct inode *inode = mapping->host; + pgoff_t index = page->index; remove_huge_page(page); - hugetlb_fix_reserve_counts(inode); + if (unlikely(hugetlb_unreserve_pages(inode, index, index + 1, 1))) + hugetlb_fix_reserve_counts(inode); + return 0; } -- 2.13.6