From patchwork Wed Jul 7 17:29:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 471637 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 E9E0DC07E9C for ; Wed, 7 Jul 2021 17:29:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCE7F61CC7 for ; Wed, 7 Jul 2021 17:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230511AbhGGRcW (ORCPT ); Wed, 7 Jul 2021 13:32:22 -0400 Received: from mga02.intel.com ([134.134.136.20]:29423 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbhGGRcV (ORCPT ); Wed, 7 Jul 2021 13:32:21 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="196517859" X-IronPort-AV: E=Sophos;i="5.84,220,1620716400"; d="scan'208";a="196517859" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2021 10:29:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,220,1620716400"; d="scan'208";a="563989995" Received: from ahunter-desktop.fi.intel.com ([10.237.72.79]) by fmsmga001.fm.intel.com with ESMTP; 07 Jul 2021 10:29:37 -0700 From: Adrian Hunter To: "Rafael J . Wysocki" Cc: Greg Kroah-Hartman , Saravana Kannan , "Martin K . Petersen" , "James E . J . Bottomley" , linux-scsi@vger.kernel.org, Avri Altman , Bean Huo , Can Guo , Asutosh Das , Bart Van Assche , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC 1/2] driver core: Add ability to delete device links of unregistered devices Date: Wed, 7 Jul 2021 20:29:47 +0300 Message-Id: <20210707172948.1025-2-adrian.hunter@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210707172948.1025-1-adrian.hunter@intel.com> References: <20210707172948.1025-1-adrian.hunter@intel.com> Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Managed device links are deleted by device_del(). However it is possible to add a device link to a consumer before device_add(), and then discover an error prevents the device from being used. In that case normally references to the device would be dropped and the device would be deleted. However the device link holds a reference to the device, so the device link and device remain indefinitely. Add a function to delete device links of an unregistered device, so that drivers can get rid of unregistered devices and their device links. To do that, the devlink_remove_symlinks() function must be amended to cope with the absence of the consumer's sysfs presence, otherwise sysfs_remove_link() will generate warnings. Signed-off-by: Adrian Hunter --- Documentation/driver-api/device_link.rst | 7 +++++-- drivers/base/core.c | 22 +++++++++++++++++++--- include/linux/device.h | 1 + 3 files changed, 25 insertions(+), 5 deletions(-) diff --git a/Documentation/driver-api/device_link.rst b/Documentation/driver-api/device_link.rst index ee913ae16371..12c0602822c8 100644 --- a/Documentation/driver-api/device_link.rst +++ b/Documentation/driver-api/device_link.rst @@ -75,7 +75,9 @@ driver is compiled as a module, the device link is added on module load and orderly deleted on unload. The same restrictions that apply to device link addition (e.g. exclusion of a parallel suspend/resume transition) apply equally to deletion. Device links managed by the driver core are deleted automatically -by it. +by it, except if the consumer device is never registered (e.g. because of an +error), in which case the device links must be explicitly removed using +:c:func:`device_links_scrap()`. Several flags may be specified on device link addition, two of which have already been mentioned above: ``DL_FLAG_STATELESS`` to express that no @@ -317,4 +319,5 @@ State machine API === -See device_link_add(), device_link_del() and device_link_remove(). +See device_link_add(), device_link_del(), device_link_remove() and +device_links_scrap(). diff --git a/drivers/base/core.c b/drivers/base/core.c index ea5b85354526..2ed32ab50b84 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -562,7 +562,8 @@ static void devlink_remove_symlinks(struct device *dev, struct device *con = link->consumer; char *buf; - sysfs_remove_link(&link->link_dev.kobj, "consumer"); + if (device_is_registered(con)) + sysfs_remove_link(&link->link_dev.kobj, "consumer"); sysfs_remove_link(&link->link_dev.kobj, "supplier"); len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), @@ -575,8 +576,10 @@ static void devlink_remove_symlinks(struct device *dev, return; } - snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); - sysfs_remove_link(&con->kobj, buf); + if (device_is_registered(con)) { + snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); + sysfs_remove_link(&con->kobj, buf); + } snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); sysfs_remove_link(&sup->kobj, buf); kfree(buf); @@ -1538,6 +1541,19 @@ static void device_links_purge(struct device *dev) device_links_write_unlock(); } +/** + * device_links_scrap - Device was never registered, delete any device links. + * @dev: Target device. + */ +void device_links_scrap(struct device *dev) +{ + if (WARN_ON(device_is_registered(dev))) + return; + + device_links_purge(dev); +} +EXPORT_SYMBOL_GPL(device_links_scrap); + #define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \ DL_FLAG_SYNC_STATE_ONLY) #define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \ diff --git a/include/linux/device.h b/include/linux/device.h index 2a22875238a6..90574f9aa8f2 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -967,6 +967,7 @@ struct device_link *device_link_add(struct device *consumer, struct device *supplier, u32 flags); void device_link_del(struct device_link *link); void device_link_remove(void *consumer, struct device *supplier); +void device_links_scrap(struct device *dev); void device_links_supplier_sync_state_pause(void); void device_links_supplier_sync_state_resume(void); From patchwork Wed Jul 7 17:29:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 471067 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 30EA7C07E95 for ; Wed, 7 Jul 2021 17:29:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B56D61CB2 for ; Wed, 7 Jul 2021 17:29:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230517AbhGGRc1 (ORCPT ); Wed, 7 Jul 2021 13:32:27 -0400 Received: from mga02.intel.com ([134.134.136.20]:29423 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230518AbhGGRcY (ORCPT ); Wed, 7 Jul 2021 13:32:24 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="196517867" X-IronPort-AV: E=Sophos;i="5.84,220,1620716400"; d="scan'208";a="196517867" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2021 10:29:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,220,1620716400"; d="scan'208";a="563990009" Received: from ahunter-desktop.fi.intel.com ([10.237.72.79]) by fmsmga001.fm.intel.com with ESMTP; 07 Jul 2021 10:29:40 -0700 From: Adrian Hunter To: "Rafael J . Wysocki" Cc: Greg Kroah-Hartman , Saravana Kannan , "Martin K . Petersen" , "James E . J . Bottomley" , linux-scsi@vger.kernel.org, Avri Altman , Bean Huo , Can Guo , Asutosh Das , Bart Van Assche , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC 2/2] scsi: ufshcd: Fix device links when BOOT WLUN fails to probe Date: Wed, 7 Jul 2021 20:29:48 +0300 Message-Id: <20210707172948.1025-3-adrian.hunter@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210707172948.1025-1-adrian.hunter@intel.com> References: <20210707172948.1025-1-adrian.hunter@intel.com> Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org If a LUN fails to probe (e.g. absent BOOT WLUN), the device will not have been registered but can still have a device link holding a reference to the device. The unwanted device link will prevent runtime suspend indefinitely, and cause some warnings if the supplier is ever deleted (e.g. by unbinding the UFS host controller). Fix by explicitly deleting the device link when SCSI destroys the SCSI device. Signed-off-by: Adrian Hunter --- drivers/scsi/ufs/ufshcd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 708b3b62fc4d..483aa74fe2c8 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5029,6 +5029,13 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev) spin_lock_irqsave(hba->host->host_lock, flags); hba->sdev_ufs_device = NULL; spin_unlock_irqrestore(hba->host->host_lock, flags); + } else { + /* + * If a LUN fails to probe (e.g. absent BOOT WLUN), the device + * will not have been registered but can still have a device + * link holding a reference to the device. + */ + device_links_scrap(&sdev->sdev_gendev); } }