From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752369AbdITEuW (ORCPT ); Wed, 20 Sep 2017 00:50:22 -0400 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:41810 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751539AbdITEqx (ORCPT ); Wed, 20 Sep 2017 00:46:53 -0400 From: "Levin, Alexander (Sasha Levin)" Cc: Gwendal Grignou , Tejun Heo , "Levin, Alexander (Sasha Levin)" X-Host: challenger.odc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH review for 3.18 30/30] libata: transport: Remove circular dependency at free time Thread-Topic: [PATCH review for 3.18 30/30] libata: transport: Remove circular dependency at free time Thread-Index: AQHTMctZd2Xw6JliIU6fBnAUNe5J4A== Date: Wed, 20 Sep 2017 04:45:57 +0000 Message-ID: <20170920044542.7571-30-alexander.levin@verizon.com> References: <20170920044542.7571-1-alexander.levin@verizon.com> In-Reply-To: <20170920044542.7571-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v8K4pA57024828 From: Gwendal Grignou [ Upstream commit d85fc67dd11e9a32966140677d4d6429ca540b25 ] Without this patch, failed probe would not free resources like irq. ata port tdev object currently hold a reference to the ata port object. Therefore the ata port object release function will not get called until the ata_tport_release is called. But that would never happen, releasing the last reference of ata port dev is done by scsi_host_release, which is called by ata_host_release when the ata port object is released. The ata device objects actually do not need to explicitly hold a reference to their real counterpart, given the transport objects are the children of these objects and device_add() is call for each child. We know the parent will not be deleted until we call the child's device_del(). Reported-by: Matthew Whitehead Tested-by: Matthew Whitehead Suggested-by: Tejun Heo Signed-off-by: Gwendal Grignou Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- drivers/ata/libata-transport.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c index fd29b7224082..43d4fbb377da 100644 --- a/drivers/ata/libata-transport.c +++ b/drivers/ata/libata-transport.c @@ -223,7 +223,6 @@ static DECLARE_TRANSPORT_CLASS(ata_port_class, static void ata_tport_release(struct device *dev) { - put_device(dev->parent); } /** @@ -283,7 +282,7 @@ int ata_tport_add(struct device *parent, device_initialize(dev); dev->type = &ata_port_type; - dev->parent = get_device(parent); + dev->parent = parent; dev->release = ata_tport_release; dev_set_name(dev, "ata%d", ap->print_id); transport_setup_device(dev); @@ -347,7 +346,6 @@ static DECLARE_TRANSPORT_CLASS(ata_link_class, static void ata_tlink_release(struct device *dev) { - put_device(dev->parent); } /** @@ -409,7 +407,7 @@ int ata_tlink_add(struct ata_link *link) int error; device_initialize(dev); - dev->parent = get_device(&ap->tdev); + dev->parent = &ap->tdev; dev->release = ata_tlink_release; if (ata_is_host_link(link)) dev_set_name(dev, "link%d", ap->print_id); @@ -587,7 +585,6 @@ static DECLARE_TRANSPORT_CLASS(ata_dev_class, static void ata_tdev_release(struct device *dev) { - put_device(dev->parent); } /** @@ -660,7 +657,7 @@ static int ata_tdev_add(struct ata_device *ata_dev) int error; device_initialize(dev); - dev->parent = get_device(&link->tdev); + dev->parent = &link->tdev; dev->release = ata_tdev_release; if (ata_is_host_link(link)) dev_set_name(dev, "dev%d.%d", ap->print_id,ata_dev->devno); -- 2.11.0