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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 C98FEC76190 for ; Fri, 26 Jul 2019 13:41:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A364322C7E for ; Fri, 26 Jul 2019 13:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148472; bh=Qt2/1Z3/byDB4IlQk0hOeMb7GKWf8oM+Z2eeZc24UfU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lmm2WtqD/EM6otgMQBFZ6g2xV2nd+6Hgrf+z0VJM16HxyA5gkGnL/YnfrDax+fyGk y4veWKqZyEsGWvJAnZBZ7aNHHfTzAJ4UDPFfw7flNgLOgHVS5OdYlGnTOuVU6CqgDC pRwYzriBLPPp0JIXcMCy7BB4tJix7yKZqEANEjWg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727830AbfGZNlL (ORCPT ); Fri, 26 Jul 2019 09:41:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:47354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727806AbfGZNlD (ORCPT ); Fri, 26 Jul 2019 09:41:03 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3C63222CB9; Fri, 26 Jul 2019 13:41:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148462; bh=Qt2/1Z3/byDB4IlQk0hOeMb7GKWf8oM+Z2eeZc24UfU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OjjpPW7v1GN99vV9Ddsmo5b1CPZ2sil7k8KzGs2GZNcuzZBAlUvo90lUqvgiHWdug 9frEFwg7ZguJGpVByRf6CNC5xSp70ex1NqD7AfNzTy/abdPwaJ1Wo2uJ4R/4S48orj o0D5y6ephx5b73+ihstS3t5CBeGDYaa876ddYqMA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Henry Burns , Shakeel Butt , Vitaly Vul , Vitaly Wool , Jonathan Adams , Andrew Morton , Linus Torvalds , Sasha Levin , linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.2 53/85] mm/z3fold.c: reinitialize zhdr structs after migration Date: Fri, 26 Jul 2019 09:39:03 -0400 Message-Id: <20190726133936.11177-53-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726133936.11177-1-sashal@kernel.org> References: <20190726133936.11177-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Henry Burns [ Upstream commit c92d2f38563db20c20c8db2f98fa1349290477d5 ] 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. Link: http://lkml.kernel.org/r/20190716000520.230595-1-henryburns@google.com Fixes: 1f862989b04ade61d3 ("mm/z3fold.c: support page migration") Signed-off-by: Henry Burns Reviewed-by: Shakeel Butt Cc: Vitaly Vul Cc: Vitaly Wool Cc: Jonathan Adams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/z3fold.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/z3fold.c b/mm/z3fold.c index e1686bf6d689..7e764b0d8c8a 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -1350,12 +1350,22 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa unlock_page(page); 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 new_zhdr->buddy is empty, + * so we only have to reinitialize it. + */ + INIT_LIST_HEAD(&new_zhdr->buddy); new_mapping = page_mapping(page); __ClearPageMovable(page); ClearPagePrivate(page); -- 2.20.1