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[1/2] libnvdimm: btt_devs: Fix locking in namespace_store

Message ID 1442409887.6868.1.camel@ingics.com (mailing list archive)
State Accepted
Commit 4be9c1fc3df9
Headers show

Commit Message

Axel Lin Sept. 16, 2015, 1:24 p.m. UTC 
Always take device_lock() before nvdimm_bus_lock() to prevent deadlock.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
 drivers/nvdimm/btt_devs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Dan Williams Sept. 16, 2015, 3:44 p.m. UTC | #1 
On Wed, Sep 16, 2015 at 6:24 AM, Axel Lin <axel.lin@ingics.com> wrote:
> Always take device_lock() before nvdimm_bus_lock() to prevent deadlock.
>
> Signed-off-by: Axel Lin <axel.lin@ingics.com>
> ---
>  drivers/nvdimm/btt_devs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
> index 59ad54a6..cb47751 100644
> --- a/drivers/nvdimm/btt_devs.c
> +++ b/drivers/nvdimm/btt_devs.c
> @@ -128,13 +128,13 @@ static ssize_t namespace_store(struct device *dev,
>         struct nd_btt *nd_btt = to_nd_btt(dev);
>         ssize_t rc;
>
> -       nvdimm_bus_lock(dev);
>         device_lock(dev);
> +       nvdimm_bus_lock(dev);
>         rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
>         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
>                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
> -       device_unlock(dev);
>         nvdimm_bus_unlock(dev);
> +       device_unlock(dev);
>
>         return rc;
>  }

Thanks Axel!  I'll also tag these for -stable.
diff mbox

Patch

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 59ad54a6..cb47751 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -128,13 +128,13 @@  static ssize_t namespace_store(struct device *dev,
 	struct nd_btt *nd_btt = to_nd_btt(dev);
 	ssize_t rc;
 
-	nvdimm_bus_lock(dev);
 	device_lock(dev);
+	nvdimm_bus_lock(dev);
 	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
 	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
-	device_unlock(dev);
 	nvdimm_bus_unlock(dev);
+	device_unlock(dev);
 
 	return rc;
 }