From patchwork Thu Mar 4 15:08:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony Iliopoulos X-Patchwork-Id: 12116395 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 D5F89C433DB for ; Thu, 4 Mar 2021 15:06:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 746FD64F70 for ; Thu, 4 Mar 2021 15:06:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 746FD64F70 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 03EB86B0008; Thu, 4 Mar 2021 10:06:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 014876B000A; Thu, 4 Mar 2021 10:05:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E1E866B000C; Thu, 4 Mar 2021 10:05:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0150.hostedemail.com [216.40.44.150]) by kanga.kvack.org (Postfix) with ESMTP id C91666B0008 for ; Thu, 4 Mar 2021 10:05:59 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 84365824999B for ; Thu, 4 Mar 2021 15:05:59 +0000 (UTC) X-FDA: 77882516838.12.DE3B537 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf15.hostedemail.com (Postfix) with ESMTP id 650C8A0009F3 for ; Thu, 4 Mar 2021 15:05:58 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1614870357; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KxivJwoKLkGdR9VUG+Tb6xBDNVrUiIBOdWtEQkd3PO4=; b=GEfuCOflnxta7g+9wf/RIEH4ei5YLgmdP/qATHP2+rtvtoHXr5N+aBPoo9G1IW6ugGNiSY Wp1O5AUA9rdA5gJrjvteRlOCu1WBAWNrJYyW63Mv4Q/aSuV1rqtfRdPIer8u2gG3/CLZB5 FeEOsiO6AukgJLhaFGcPmNUyB/LP1DQ= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 419F7AE04; Thu, 4 Mar 2021 15:05:57 +0000 (UTC) From: Anthony Iliopoulos To: Greg Kroah-Hartman , Jens Axboe , Andrew Morton , Matthew Wilcox Cc: stable@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH STABLE 4.4] swap: fix swapfile page to sector mapping Date: Thu, 4 Mar 2021 16:08:22 +0100 Message-Id: <20210304150824.29878-3-ailiop@suse.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210304150824.29878-1-ailiop@suse.com> References: <20210304150824.29878-1-ailiop@suse.com> MIME-Version: 1.0 X-Stat-Signature: onkumewcnxqjpjc6yzbqx4endchrdbh4 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 650C8A0009F3 Received-SPF: none (suse.com>: No applicable sender policy available) receiver=imf15; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614870358-279675 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: commit caf6912f3f4af7232340d500a4a2008f81b93f14 upstream. Fix block device sector offset calculation for swap page io on top of blockdevs that provide a rw_page operation and do page-sized io directly (without the block layer). Currently swap_page_sector() maps a swap page into a blockdev sector by obtaining the swap page offset (swap map slot), but ignores the swapfile starting offset into the blockdev. In setups where swapfiles are sitting on top of a filesystem, this results into swapping out activity potentially overwriting filesystem blocks that fall outside the swapfile region. [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 --- mm/page_io.c | 11 +++-------- mm/swapfile.c | 2 +- 2 files changed, 4 insertions(+), 9 deletions(-) diff --git a/mm/page_io.c b/mm/page_io.c index b995a5ba5e8f..ab92cd559404 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -32,7 +32,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags, 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, struct writeback_control *wbc, 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; diff --git a/mm/swapfile.c b/mm/swapfile.c index 8e25ff2b693a..b338d8829239 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1653,7 +1653,7 @@ sector_t map_swap_page(struct page *page, struct block_device **bdev) { swp_entry_t entry; entry.val = page_private(page); - return map_swap_entry(entry, bdev); + return map_swap_entry(entry, bdev) << (PAGE_SHIFT - 9); } /*