Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1733595

[PATCH for 4.9 37/39] libata: transport: Remove circular dependency at free time

Show all headers | View raw

From: Gwendal Grignou <gwendal@chromium.org>

[ 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 <tedheadster@gmail.com>
Tested-by: Matthew Whitehead <tedheadster@gmail.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 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 7ef16c085058..20e2b7ad8925 100644
--- a/drivers/ata/libata-transport.c
+++ b/drivers/ata/libata-transport.c
@@ -224,7 +224,6 @@ static DECLARE_TRANSPORT_CLASS(ata_port_class,
 
 static void ata_tport_release(struct device *dev)
 {
-	put_device(dev->parent);
 }
 
 /**
@@ -284,7 +283,7 @@ 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);
@@ -348,7 +347,6 @@ static DECLARE_TRANSPORT_CLASS(ata_link_class,
 
 static void ata_tlink_release(struct device *dev)
 {
-	put_device(dev->parent);
 }
 
 /**
@@ -410,7 +408,7 @@ 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);
@@ -589,7 +587,6 @@ static DECLARE_TRANSPORT_CLASS(ata_dev_class,
 
 static void ata_tdev_release(struct device *dev)
 {
-	put_device(dev->parent);
 }
 
 /**
@@ -662,7 +659,7 @@ 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

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH for 4.9 18/39] iommu/exynos: Block SYSMMU while invalidating  FLPD cache "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 27/39] x86/acpi: Restore the order of CPU IDs "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 22/39] netfilter: nfnl_cthelper: fix incorrect  helper->expect_class_max "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 35/39] xfs: remove kmem_zalloc_greedy "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 31/39] rds: ib: add error handle "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 24/39] nfs: make nfs4_cb_sv_ops static "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 32/39] md/raid10: submit bio directly to replacement  disk "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 38/39] ARM: dts: BCM5301X: Fix memory start address "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 29/39] arm64: kasan: avoid bad virt_to_pfn() "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 39/39] tools/power turbostat: bugfix: GFXMHz column  not changing "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 20/39] MIPS: smp-cps: Fix retrieval of VPE mask on big  endian CPUs "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 28/39] iommu/io-pgtable-arm: Check for leaf entry  before dereferencing it "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 23/39] parisc: perf: Fix potential NULL pointer  dereference "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 34/39] i2c: meson: fix wrong variable usage in  meson_i2c_put_data "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 36/39] ASoC: wm_adsp: Return an error on write to a  disabled volatile control "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 25/39] ibmvnic: Free tx/rx scrq pointer array when  releasing sub-crqs "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 33/39] netfilter: nf_tables: set pktinfo->thoff at AH  header if found "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200
  [PATCH for 4.9 37/39] libata: transport: Remove circular dependency  at free time "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-18 02:50 +0200

csiph-web