From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 153C2C7618F for ; Mon, 15 Jul 2019 16:47:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC7C720861 for ; Mon, 15 Jul 2019 16:47:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="YeBZBrSX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731467AbfGOQrm (ORCPT ); Mon, 15 Jul 2019 12:47:42 -0400 Received: from mail-qk1-f202.google.com ([209.85.222.202]:56149 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729941AbfGOQrm (ORCPT ); Mon, 15 Jul 2019 12:47:42 -0400 Received: by mail-qk1-f202.google.com with SMTP id m198so14146656qke.22 for ; Mon, 15 Jul 2019 09:47:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=uefiGP790QPlHmhELnOTMDg4Gfv1ldPwSxnEHTELlh4=; b=YeBZBrSXtK9i0HJSVVv2OwHsZlDPNrQA38z/OP0Renlqzd0x8ogg6n9oOCOxRZ/qJX 2AFyJyFpg1T1qww+sFCfX4m+DLyS53IgMyeu1hTMwdzvac1reuMswpgPAbjchx8I44XD fTWAXvuAXFBDzH4LdWpWN5jKmuC0JAYcMKLII//xrW7oz2dgVjc34ys4nbJDLcGFLFg6 hbJD7DHbO3okpeMb0YQw1fsqgya5/i7c5TpasVmFLqZuZZFs9wUa/O7K2vxk3tAXzORg +TBEy4PIZSjdM5zWz8MjB1WoK2H5ny25+wl5R6aKGS+eF9K8N/Y14yXFkgTIXR1hGUPR THYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=uefiGP790QPlHmhELnOTMDg4Gfv1ldPwSxnEHTELlh4=; b=TEyW3XY7xXyllMbruBcwMbzvt8KAE0VgRuigyD9NnemFnVvNBQWQaSSCUJHaEj0QrS wQtznCHrIUGa5fjdnTMukJAetAhnbV1iQulG02CrdDxW/f5noED6ISZJo+/NLoLKieCf p/2S3AxSWO0/2a9x470xxFOlcJcohAuL1FPoYobkPZDsgsdeHyX6P/j3dPdWkhP10ZJk z3aSrWr4Pm3wKSuZ5HN3w/deIeEzODjTnkKPOoHDpyG2MJR5hBwWNSjWRuBBlYNdRGGt 3rxh8kTsVG7qXYmH6m8JypTgXrV+0KlK7cE7PNdNc3JEr9DhzpR2rMmrxQos+eokA8Cp dsAA== X-Gm-Message-State: APjAAAXMVck8Kgd/7bayKQ+Vl/NLzQIUdsro0DcV1JUivQIYG5j6xdAp 4pxaVe6Swnl7aURTK0S8ff8wVuQU7yEEjmS2 X-Google-Smtp-Source: APXvYqxhV21lnl98vfMuXVfbZYtgXl89P2Xqlu5YAtnRRfAoENjqyw61PjICMmXKSWQSqVMA9ImLdH2rX49JwDhR X-Received: by 2002:a37:a343:: with SMTP id m64mr17595893qke.75.1563209261293; Mon, 15 Jul 2019 09:47:41 -0700 (PDT) Date: Mon, 15 Jul 2019 09:47:05 -0700 Message-Id: <20190715164705.220693-1-henryburns@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.510.g264f2c817a-goog Subject: [PATCH] mm/z3fold.c: Reinitialize zhdr structs after migration From: Henry Burns To: Vitaly Wool , Andrew Morton Cc: Vitaly Vul , Shakeel Butt , Jonathan Adams , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Henry Burns Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org z3fold_page_migration() calls memcpy(new_zhdr, zhdr, PAGE_SIZE). However, zhdr contains fields that can't be directly coppied over (ex: list_head, a circular linked list). We only need to initialize the linked lists in new_zhdr, as z3fold_isolate_page() already ensures that these lists are empty. Additionally it is possible that zhdr->work has been placed in a workqueue. In this case we shouldn't migrate the page, as zhdr->work references zhdr as opposed to new_zhdr. Fixes: bba4c5f96ce4 ("mm/z3fold.c: support page migration") Signed-off-by: Henry Burns --- mm/z3fold.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/z3fold.c b/mm/z3fold.c index 42ef9955117c..9da471bcab93 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -1352,12 +1352,22 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa z3fold_page_unlock(zhdr); return -EBUSY; } + if (work_pending(&zhdr->work)) { + z3fold_page_unlock(zhdr); + return -EAGAIN; + } new_zhdr = page_address(newpage); memcpy(new_zhdr, zhdr, PAGE_SIZE); newpage->private = page->private; page->private = 0; z3fold_page_unlock(zhdr); spin_lock_init(&new_zhdr->page_lock); + INIT_WORK(&new_zhdr->work, compact_page_work); + /* + * z3fold_page_isolate() ensures that this list is empty, so we only + * have to reinitialize it. + */ + INIT_LIST_HEAD(&new_zhdr->buddy); new_mapping = page_mapping(page); __ClearPageMovable(page); ClearPagePrivate(page); -- 2.22.0.510.g264f2c817a-goog