[PATCH 04/62] dax/bus.c: Fix a locking bug

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* [PATCH 04/62] dax/bus.c: Fix a locking bug
       [not found] <20260223220102.2158611-1-bart.vanassche@linux.dev>
@ 2026-02-23 22:00 ` Bart Van Assche
  2026-02-23 22:50   ` dan.j.williams
  0 siblings, 1 reply; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 22:00 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long, linux-kernel,
	Marco Elver, Christoph Hellwig, Steven Rostedt, Nick Desaulniers,
	Nathan Chancellor, Kees Cook, Jann Horn, Bart Van Assche,
	Dan Williams, Vishal Verma, Dave Jiang, Alison Schofield, nvdimm,
	linux-cxl

From: Bart Van Assche <bvanassche@acm.org>

Only unlock dax_dev_rwsem if it has been locked. This locking bug was
detected by the Clang thread-safety analyzer.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: nvdimm@lists.linux.dev
Cc: linux-cxl@vger.kernel.org
Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/dax/bus.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index c94c09622516..ebd3806c34e5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1117,11 +1117,10 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 	}
 	rc = down_write_killable(&dax_dev_rwsem);
 	if (rc)
-		goto err_dev;
+		goto err_region;
 
 	rc = dev_dax_resize(dax_region, dev_dax, val);
 
-err_dev:
 	up_write(&dax_dev_rwsem);
 err_region:
 	up_write(&dax_region_rwsem);

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH 04/62] dax/bus.c: Fix a locking bug
  2026-02-23 22:00 ` [PATCH 04/62] dax/bus.c: Fix a locking bug Bart Van Assche
@ 2026-02-23 22:50   ` dan.j.williams
  2026-02-24 12:45     ` Jonathan Cameron
  0 siblings, 1 reply; 5+ messages in thread
From: dan.j.williams @ 2026-02-23 22:50 UTC (permalink / raw)
  To: Bart Van Assche, Peter Zijlstra
  Cc: Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long, linux-kernel,
	Marco Elver, Christoph Hellwig, Steven Rostedt, Nick Desaulniers,
	Nathan Chancellor, Kees Cook, Jann Horn, Bart Van Assche,
	Dan Williams, Vishal Verma, Dave Jiang, Alison Schofield, nvdimm,
	linux-cxl

Bart Van Assche wrote:
> From: Bart Van Assche <bvanassche@acm.org>
> 
> Only unlock dax_dev_rwsem if it has been locked. This locking bug was
> detected by the Clang thread-safety analyzer.
> 
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: nvdimm@lists.linux.dev
> Cc: linux-cxl@vger.kernel.org
> Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>

Looks good,

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 04/62] dax/bus.c: Fix a locking bug
  2026-02-23 22:50   ` dan.j.williams
@ 2026-02-24 12:45     ` Jonathan Cameron
  0 siblings, 0 replies; 5+ messages in thread
From: Jonathan Cameron @ 2026-02-24 12:45 UTC (permalink / raw)
  To: dan.j.williams
  Cc: Bart Van Assche, Peter Zijlstra, Ingo Molnar, Will Deacon,
	Boqun Feng, Waiman Long, linux-kernel, Marco Elver,
	Christoph Hellwig, Steven Rostedt, Nick Desaulniers,
	Nathan Chancellor, Kees Cook, Jann Horn, Bart Van Assche,
	Vishal Verma, Dave Jiang, Alison Schofield, nvdimm, linux-cxl

On Mon, 23 Feb 2026 14:50:49 -0800
<dan.j.williams@intel.com> wrote:

> Bart Van Assche wrote:
> > From: Bart Van Assche <bvanassche@acm.org>
> > 
> > Only unlock dax_dev_rwsem if it has been locked. This locking bug was
> > detected by the Clang thread-safety analyzer.
> > 
> > Cc: Dan Williams <dan.j.williams@intel.com>
> > Cc: Vishal Verma <vishal.l.verma@intel.com>
> > Cc: Dave Jiang <dave.jiang@intel.com>
> > Cc: Alison Schofield <alison.schofield@intel.com>
> > Cc: nvdimm@lists.linux.dev
> > Cc: linux-cxl@vger.kernel.org
> > Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
> > Signed-off-by: Bart Van Assche <bvanassche@acm.org>  
> 
> Looks good,
> 
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> 

Agreed
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

Maybe worth some ACQUIRE() magic as a follow up.


^ permalink raw reply	[flat|nested] 5+ messages in thread

[parent not found: <20260223215118.2154194-1-bvanassche@acm.org>]

* [PATCH 04/62] dax/bus.c: Fix a locking bug
       [not found] <20260223215118.2154194-1-bvanassche@acm.org>
@ 2026-02-23 21:50 ` Bart Van Assche
  0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 21:50 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: Ingo Molnar, Will Deacon, Boqun Feng, Waiman Long, linux-kernel,
	Marco Elver, Christoph Hellwig, Steven Rostedt, Nick Desaulniers,
	Nathan Chancellor, Kees Cook, Jann Horn, Bart Van Assche,
	Dan Williams, Vishal Verma, Dave Jiang, Alison Schofield, nvdimm,
	linux-cxl

Only unlock dax_dev_rwsem if it has been locked. This locking bug was
detected by the Clang thread-safety analyzer.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: nvdimm@lists.linux.dev
Cc: linux-cxl@vger.kernel.org
Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/dax/bus.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index c94c09622516..ebd3806c34e5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1117,11 +1117,10 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 	}
 	rc = down_write_killable(&dax_dev_rwsem);
 	if (rc)
-		goto err_dev;
+		goto err_region;
 
 	rc = dev_dax_resize(dax_region, dev_dax, val);
 
-err_dev:
 	up_write(&dax_dev_rwsem);
 err_region:
 	up_write(&dax_region_rwsem);

^ permalink raw reply related	[flat|nested] 5+ messages in thread

[parent not found: <20260223214950.2153735-1-bvanassche@acm.org>]

* [PATCH 04/62] dax/bus.c: Fix a locking bug
       [not found] <20260223214950.2153735-1-bvanassche@acm.org>
@ 2026-02-23 21:48 ` Bart Van Assche
  0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2026-02-23 21:48 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: Bart Van Assche, Dan Williams, Vishal Verma, Dave Jiang,
	Alison Schofield, nvdimm, linux-cxl

Only unlock dax_dev_rwsem if it has been locked. This locking bug was
detected by the Clang thread-safety analyzer.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: nvdimm@lists.linux.dev
Cc: linux-cxl@vger.kernel.org
Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/dax/bus.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index c94c09622516..ebd3806c34e5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1117,11 +1117,10 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 	}
 	rc = down_write_killable(&dax_dev_rwsem);
 	if (rc)
-		goto err_dev;
+		goto err_region;
 
 	rc = dev_dax_resize(dax_region, dev_dax, val);
 
-err_dev:
 	up_write(&dax_dev_rwsem);
 err_region:
 	up_write(&dax_region_rwsem);

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2026-02-24 12:45 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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     [not found] <20260223220102.2158611-1-bart.vanassche@linux.dev>
2026-02-23 22:00 ` [PATCH 04/62] dax/bus.c: Fix a locking bug Bart Van Assche
2026-02-23 22:50   ` dan.j.williams
2026-02-24 12:45     ` Jonathan Cameron
     [not found] <20260223215118.2154194-1-bvanassche@acm.org>
2026-02-23 21:50 ` Bart Van Assche
     [not found] <20260223214950.2153735-1-bvanassche@acm.org>
2026-02-23 21:48 ` Bart Van Assche

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