From patchwork Fri Aug 4 02:51:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Lin X-Patchwork-Id: 9880355 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 70E61602B8 for ; Fri, 4 Aug 2017 02:52:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6329228949 for ; Fri, 4 Aug 2017 02:52:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 57E9028962; Fri, 4 Aug 2017 02:52:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CDA0F28949 for ; Fri, 4 Aug 2017 02:52:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751864AbdHDCwL (ORCPT ); Thu, 3 Aug 2017 22:52:11 -0400 Received: from lucky1.263xmail.com ([211.157.147.135]:52713 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbdHDCwK (ORCPT ); Thu, 3 Aug 2017 22:52:10 -0400 Received: from shawn.lin?rock-chips.com (unknown [192.168.167.174]) by lucky1.263xmail.com (Postfix) with ESMTP id 733008ED; Fri, 4 Aug 2017 10:52:08 +0800 (CST) X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 Received: from localhost.localdomain (localhost [127.0.0.1]) by smtp.263.net (Postfix) with ESMTPA id 1EB3B39A; Fri, 4 Aug 2017 10:52:06 +0800 (CST) X-RL-SENDER: shawn.lin@rock-chips.com X-FST-TO: ulf.hansson@linaro.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: shawn.lin@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-SENDER: lintao@rock-chips.com X-DNS-TYPE: 0 Received: from localhost.localdomain (unknown [58.22.7.114]) by smtp.263.net (Postfix) whith ESMTP id 4133H755JG; Fri, 04 Aug 2017 10:52:07 +0800 (CST) From: Shawn Lin To: Ulf Hansson Cc: linux-mmc@vger.kernel.org, Shawn Lin Subject: [PATCH] mmc: block: cast a error log for unbalanced mmc_blk_{open, release} Date: Fri, 4 Aug 2017 10:51:42 +0800 Message-Id: <1501815102-19376-1-git-send-email-shawn.lin@rock-chips.com> X-Mailer: git-send-email 1.9.1 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The intention for this patch is to help folks debug the failure like this: dwmmc_rockchip fe320000.dwmmc: IDMAC supports 32-bit address mode. dwmmc_rockchip fe320000.dwmmc: Using internal DMA controller. dwmmc_rockchip fe320000.dwmmc: Version ID is 270a dwmmc_rockchip fe320000.dwmmc: DW MMC controller at irq 28,32 bit host data width,256 deep fifo dwmmc_rockchip fe320000.dwmmc: Got CD GPIO mmc_host mmc0: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0) mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 50000000Hz, actual 50000000HZ div = 0) mmc0: new high speed SDHC card at address 0007 mmcblk: probe of mmc0:0007 failed with error -28 It's quite annoying that some buggy userspace deamon miss the disk remove uevent sometimes so it would finally make the SD card not work. So from the dmesg it only shows a errno of -28 but still don't understand what happened. For quick reproduce this, we could set max_devices to 8 and run for i in $(seq 1 9); do echo "========================" $i echo fe320000.dwmmc > /sys/bus/platform/drivers/dwmmc_rockchip/unbind sleep .5 echo fe320000.dwmmc > /sys/bus/platform/drivers/dwmmc_rockchip/bind sleep .5 mount -t vfat /dev/mmcblk0 /mnt sleep .5 done Signed-off-by: Shawn Lin --- drivers/mmc/core/block.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index a11bead..3ede32a 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -1985,8 +1985,24 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, int devidx, ret; devidx = ida_simple_get(&mmc_blk_ida, 0, max_devices, GFP_KERNEL); - if (devidx < 0) + if (devidx < 0) { + /* + * The reason for why we could get -ENOSPC here for + * removable devices is that probably userspace mount + * the partition but forget to umount it which makes + * it fail to release md->usage via mmc_blk_release, + * so as a result it leaks the device ID and finally + * breaks the reference counting for mmc block layer. + * It's uerspace's responsibility to guarantee it but + * we could cast an explcit error log here to clarify + * the situation. + */ + if (mmc_card_is_removable(card->host) && devidx == -ENOSPC) + dev_err(mmc_dev(card->host), + "possible unblanced mount/umount detected\n"); + return ERR_PTR(devidx); + } md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL); if (!md) {