From patchwork Fri Mar 5 12:22:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 394899 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 3E149C4360C for ; Fri, 5 Mar 2021 12:44:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20A2A6501C for ; Fri, 5 Mar 2021 12:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233617AbhCEMoa (ORCPT ); Fri, 5 Mar 2021 07:44:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:32810 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232815AbhCEMn7 (ORCPT ); Fri, 5 Mar 2021 07:43:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DBD666501E; Fri, 5 Mar 2021 12:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614948239; bh=5A8MzKuBa5QwN4+e03SXTTAE+aNwmgxjioVn5zLiJhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yS7j+TWNiGuk5A2qb52wl3sCit6GD5pZqYQagi0V7gXKU4j3GK+foJbK+/Ifw95uE N1fgMiX/pdKUpe7aBrn3NaO5mRbvdKxFPxcDo10hDUEWgDYUoZdBdwUddUodYPyxTN kwrO/PSOIi6Add/zk7w9vcf6FQs1pGBaxrsAeB8A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anthony Iliopoulos , Jens Axboe Subject: [PATCH 4.4 29/30] swap: fix swapfile read/write offset Date: Fri, 5 Mar 2021 13:22:58 +0100 Message-Id: <20210305120850.860813577@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210305120849.381261651@linuxfoundation.org> References: <20210305120849.381261651@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jens Axboe commit caf6912f3f4af7232340d500a4a2008f81b93f14 upstream. We're not factoring in the start of the file for where to write and read the swapfile, which leads to very unfortunate side effects of writing where we should not be... [This issue only affects swapfiles on filesystems on top of blockdevs that implement rw_page ops (brd, zram, btt, pmem), and not on top of any other block devices, in contrast to the upstream commit fix.] Fixes: dd6bd0d9c7db ("swap: use bdev_read_page() / bdev_write_page()") Cc: stable@vger.kernel.org # 4.4 Signed-off-by: Anthony Iliopoulos Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- mm/page_io.c | 11 +++-------- mm/swapfile.c | 2 +- 2 files changed, 4 insertions(+), 9 deletions(-) --- a/mm/page_io.c +++ b/mm/page_io.c @@ -32,7 +32,6 @@ static struct bio *get_swap_bio(gfp_t gf bio = bio_alloc(gfp_flags, 1); if (bio) { bio->bi_iter.bi_sector = map_swap_page(page, &bio->bi_bdev); - bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9; bio->bi_end_io = end_io; bio_add_page(bio, page, PAGE_SIZE, 0); @@ -244,11 +243,6 @@ out: return ret; } -static sector_t swap_page_sector(struct page *page) -{ - return (sector_t)__page_file_index(page) << (PAGE_CACHE_SHIFT - 9); -} - int __swap_writepage(struct page *page, struct writeback_control *wbc, bio_end_io_t end_write_func) { @@ -297,7 +291,8 @@ int __swap_writepage(struct page *page, return ret; } - ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc); + ret = bdev_write_page(sis->bdev, map_swap_page(page, &sis->bdev), + page, wbc); if (!ret) { count_vm_event(PSWPOUT); return 0; @@ -345,7 +340,7 @@ int swap_readpage(struct page *page) return ret; } - ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); + ret = bdev_read_page(sis->bdev, map_swap_page(page, &sis->bdev), page); if (!ret) { count_vm_event(PSWPIN); return 0; --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1653,7 +1653,7 @@ sector_t map_swap_page(struct page *page { swp_entry_t entry; entry.val = page_private(page); - return map_swap_entry(entry, bdev); + return map_swap_entry(entry, bdev) << (PAGE_SHIFT - 9); } /*