From patchwork Tue Apr 11 12:19:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Yu X-Patchwork-Id: 672570 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 022BEC76196 for ; Tue, 11 Apr 2023 04:23:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229697AbjDKEX2 (ORCPT ); Tue, 11 Apr 2023 00:23:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230070AbjDKEX0 (ORCPT ); Tue, 11 Apr 2023 00:23:26 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7745C2722; Mon, 10 Apr 2023 21:23:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1681187002; x=1712723002; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=iNsCeMH7AuoBioPIEJx2jiuo1QskSURMZ+m/FQDWG+w=; b=cX4dDzq9Kl98pLSkdom+KVugZAiriSyKjBMFCMlydk1KHYX48S+slFPd y76MI81Miibc/C1PJSNZVfkT1oxJfxThyhGeD943IR8AI5fxJtJWU52Rd d5Qv6yO1VggpDjHI3zjozffjgs8Xj95H3vAQgubpoLWJoAKuBvlFKG6V4 ZnVWW5qYV42zp9/HTowFpb6seP3Wl2rCHjoGGVpYNlDI45n6q6/Dp49s0 ri3BBFUhCxErpEpwxwabyvcmJSpQFp9DbtVa/DgHEgv1wOofcDZnU68Zp h0xtTlDrgarTVnlE+EfurU3fXqvTVgij55vE4YgoqkB4Ni78H7bwQeXJt w==; X-IronPort-AV: E=McAfee;i="6600,9927,10676"; a="341010207" X-IronPort-AV: E=Sophos;i="5.98,335,1673942400"; d="scan'208";a="341010207" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Apr 2023 21:23:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10676"; a="721045456" X-IronPort-AV: E=Sophos;i="5.98,335,1673942400"; d="scan'208";a="721045456" Received: from chenyu-dev.sh.intel.com ([10.239.158.170]) by orsmga001.jf.intel.com with ESMTP; 10 Apr 2023 21:23:18 -0700 From: Chen Yu To: "Rafael J. Wysocki" , Len Brown Cc: Ye Bin , Pavankumar Kondeti , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Chen Yu , Yifan Li Subject: [PATCH v2 2/2] PM: hibernate: Do not get block device exclusively in test_resume mode Date: Tue, 11 Apr 2023 20:19:13 +0800 Message-Id: <8f917ae09c7a09d1841824908107d6c79a6cd090.1681186310.git.yu.c.chen@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The system refused to do a test_resume because it found that the swap device has already been taken by someone else. Specificly, the swsusp_check()->blkdev_get_by_dev(FMODE_EXCL) is supposed to do this check. Steps to reproduce: dd if=/dev/zero of=/swapfile bs=$(cat /proc/meminfo | awk '/MemTotal/ {print $2}') count=1024 conv=notrunc mkswap /swapfile swapon /swapfile swap-offset /swapfile echo 34816 > /sys/power/resume_offset echo test_resume > /sys/power/disk echo disk > /sys/power/state PM: Using 3 thread(s) for compression PM: Compressing and saving image data (293150 pages)... PM: Image saving progress: 0% PM: Image saving progress: 10% ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata1.00: configured for UDMA/100 ata2: SATA link down (SStatus 0 SControl 300) ata5: SATA link down (SStatus 0 SControl 300) ata6: SATA link down (SStatus 0 SControl 300) ata3: SATA link down (SStatus 0 SControl 300) ata4: SATA link down (SStatus 0 SControl 300) PM: Image saving progress: 20% PM: Image saving progress: 30% PM: Image saving progress: 40% PM: Image saving progress: 50% pcieport 0000:00:02.5: pciehp: Slot(0-5): No device found PM: Image saving progress: 60% PM: Image saving progress: 70% PM: Image saving progress: 80% PM: Image saving progress: 90% PM: Image saving done PM: hibernation: Wrote 1172600 kbytes in 2.70 seconds (434.29 MB/s) PM: S| PM: hibernation: Basic memory bitmaps freed PM: Image not found (code -16) This is because when using the swapfile as the hibernation storage, the block device where the swapfile is located has already been mounted by the OS distribution(usually been mounted as the rootfs). This is not an issue for normal hibernation, because software_resume()->swsusp_check() happens before the block device(rootfs) mount. But it is a problem for the test_resume mode. Because when test_resume happens, the block device has been mounted already. Thus remove the FMODE_EXCL for test_resume mode. This would not be a problem because in test_resume stage, the processes have already been frozen, and the race condition described in Commit 39fbef4b0f77 ("PM: hibernate: Get block device exclusively in swsusp_check()") is unlikely to happen. Fixes: 39fbef4b0f77 ("PM: hibernate: Get block device exclusively in swsusp_check()") Reported-by: Yifan Li Suggested-by: Pavankumar Kondeti Signed-off-by: Chen Yu --- kernel/power/hibernate.c | 5 +++-- kernel/power/swap.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index aa551b093c3f..defc2257b052 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -688,18 +688,19 @@ static int load_image_and_restore(void) { int error; unsigned int flags; + fmode_t mode = snapshot_test ? FMODE_READ : (FMODE_READ | FMODE_EXCL); pm_pr_dbg("Loading hibernation image.\n"); lock_device_hotplug(); error = create_basic_memory_bitmaps(); if (error) { - swsusp_close(FMODE_READ | FMODE_EXCL); + swsusp_close(mode); goto Unlock; } error = swsusp_read(&flags); - swsusp_close(FMODE_READ | FMODE_EXCL); + swsusp_close(mode); if (!error) error = hibernation_restore(flags & SF_PLATFORM_MODE); diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 36a1df48280c..0f699cd96a89 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -1518,9 +1518,10 @@ int swsusp_check(void) { int error; void *holder; + fmode_t mode = snapshot_test ? FMODE_READ : (FMODE_READ | FMODE_EXCL); hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, - FMODE_READ | FMODE_EXCL, &holder); + mode, &holder); if (!IS_ERR(hib_resume_bdev)) { set_blocksize(hib_resume_bdev, PAGE_SIZE); clear_page(swsusp_header); @@ -1547,7 +1548,7 @@ int swsusp_check(void) put: if (error) - blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL); + blkdev_put(hib_resume_bdev, mode); else pr_debug("Image signature found, resuming\n"); } else {