From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: [PATCHv6 11/22] thp, mm: warn if we try to use replace_page_cache_page() with THP Date: Mon, 23 Sep 2013 15:05:39 +0300 Message-ID: <1379937950-8411-12-git-send-email-kirill.shutemov@linux.intel.com> References: <1379937950-8411-1-git-send-email-kirill.shutemov@linux.intel.com> Cc: Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , Dave Hansen , Ning Qu , Alexander Shishkin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" To: Andrea Arcangeli , Andrew Morton Return-path: Received: from mga14.intel.com ([143.182.124.37]:59137 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753789Ab3IWMGJ (ORCPT ); Mon, 23 Sep 2013 08:06:09 -0400 In-Reply-To: <1379937950-8411-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: replace_page_cache_page() is only used by FUSE. It's unlikely that we will support THP in FUSE page cache any soon. Let's pospone implemetation of THP handling in replace_page_cache_page() until any will use it. -EINVAL and WARN_ONCE() for now. Signed-off-by: Kirill A. Shutemov --- mm/filemap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 60478ebeda..3421bcaed4 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -417,6 +417,10 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) { int error; + if (WARN_ONCE(PageTransHuge(old) || PageTransHuge(new), + "unexpected transhuge page\n")) + return -EINVAL; + VM_BUG_ON(!PageLocked(old)); VM_BUG_ON(!PageLocked(new)); VM_BUG_ON(new->mapping); -- 1.8.4.rc3