diff mbox

[2/2] drm: set dev_mapping before calling drm_open_helper

Message ID 1351532101-8523-2-git-send-email-ihadzic@research.bell-labs.com (mailing list archive)
State Accepted
Headers show

Commit Message

Ilija Hadzic Oct. 29, 2012, 5:35 p.m. UTC
Some drivers (specifically vmwgfx) look at dev_mapping
in their open hook, so we have to set dev->dev_mapping
earlier in the process.

Reference:
http://lists.freedesktop.org/archives/dri-devel/2012-October/029420.html

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/drm_fops.c | 47 +++++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 17 deletions(-)

Comments

Thomas Hellstrom Oct. 30, 2012, 1:54 p.m. UTC | #1
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>

On 10/29/2012 06:35 PM, Ilija Hadzic wrote:
> Some drivers (specifically vmwgfx) look at dev_mapping
> in their open hook, so we have to set dev->dev_mapping
> earlier in the process.
>
> Reference:
> http://lists.freedesktop.org/archives/dri-devel/2012-October/029420.html
>
> Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
> Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
> Cc: stable@vger.kernel.org
> ---
>   drivers/gpu/drm/drm_fops.c | 47 +++++++++++++++++++++++++++++-----------------
>   1 file changed, 30 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
> index af68eca..133b413 100644
> --- a/drivers/gpu/drm/drm_fops.c
> +++ b/drivers/gpu/drm/drm_fops.c
> @@ -121,6 +121,8 @@ int drm_open(struct inode *inode, struct file *filp)
>   	int minor_id = iminor(inode);
>   	struct drm_minor *minor;
>   	int retcode = 0;
> +	int need_setup = 0;
> +	struct address_space *old_mapping;
>   
>   	minor = idr_find(&drm_minors_idr, minor_id);
>   	if (!minor)
> @@ -132,26 +134,37 @@ int drm_open(struct inode *inode, struct file *filp)
>   	if (drm_device_is_unplugged(dev))
>   		return -ENODEV;
>   
> +	if (!dev->open_count++)
> +		need_setup = 1;
> +	mutex_lock(&dev->struct_mutex);
> +	old_mapping = dev->dev_mapping;
> +	if (old_mapping == NULL)
> +		dev->dev_mapping = &inode->i_data;
> +	/* ihold ensures nobody can remove inode with our i_data */
> +	ihold(container_of(dev->dev_mapping, struct inode, i_data));
> +	inode->i_mapping = dev->dev_mapping;
> +	filp->f_mapping = dev->dev_mapping;
> +	mutex_unlock(&dev->struct_mutex);
> +
>   	retcode = drm_open_helper(inode, filp, dev);
> -	if (!retcode) {
> -		atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
> -		if (!dev->open_count++) {
> -			retcode = drm_setup(dev);
> -			if (retcode)
> -				dev->open_count--;
> -		}
> -	}
> -	if (!retcode) {
> -		mutex_lock(&dev->struct_mutex);
> -		if (dev->dev_mapping == NULL)
> -			dev->dev_mapping = &inode->i_data;
> -		/* ihold ensures nobody can remove inode with our i_data */
> -		ihold(container_of(dev->dev_mapping, struct inode, i_data));
> -		inode->i_mapping = dev->dev_mapping;
> -		filp->f_mapping = dev->dev_mapping;
> -		mutex_unlock(&dev->struct_mutex);
> +	if (retcode)
> +		goto err_undo;
> +	atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
> +	if (need_setup) {
> +		retcode = drm_setup(dev);
> +		if (retcode)
> +			goto err_undo;
>   	}
> +	return 0;
>   
> +err_undo:
> +	mutex_lock(&dev->struct_mutex);
> +	filp->f_mapping = old_mapping;
> +	inode->i_mapping = old_mapping;
> +	iput(container_of(dev->dev_mapping, struct inode, i_data));
> +	dev->dev_mapping = old_mapping;
> +	mutex_unlock(&dev->struct_mutex);
> +	dev->open_count--;
>   	return retcode;
>   }
>   EXPORT_SYMBOL(drm_open);
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index af68eca..133b413 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -121,6 +121,8 @@  int drm_open(struct inode *inode, struct file *filp)
 	int minor_id = iminor(inode);
 	struct drm_minor *minor;
 	int retcode = 0;
+	int need_setup = 0;
+	struct address_space *old_mapping;
 
 	minor = idr_find(&drm_minors_idr, minor_id);
 	if (!minor)
@@ -132,26 +134,37 @@  int drm_open(struct inode *inode, struct file *filp)
 	if (drm_device_is_unplugged(dev))
 		return -ENODEV;
 
+	if (!dev->open_count++)
+		need_setup = 1;
+	mutex_lock(&dev->struct_mutex);
+	old_mapping = dev->dev_mapping;
+	if (old_mapping == NULL)
+		dev->dev_mapping = &inode->i_data;
+	/* ihold ensures nobody can remove inode with our i_data */
+	ihold(container_of(dev->dev_mapping, struct inode, i_data));
+	inode->i_mapping = dev->dev_mapping;
+	filp->f_mapping = dev->dev_mapping;
+	mutex_unlock(&dev->struct_mutex);
+
 	retcode = drm_open_helper(inode, filp, dev);
-	if (!retcode) {
-		atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
-		if (!dev->open_count++) {
-			retcode = drm_setup(dev);
-			if (retcode)
-				dev->open_count--;
-		}
-	}
-	if (!retcode) {
-		mutex_lock(&dev->struct_mutex);
-		if (dev->dev_mapping == NULL)
-			dev->dev_mapping = &inode->i_data;
-		/* ihold ensures nobody can remove inode with our i_data */
-		ihold(container_of(dev->dev_mapping, struct inode, i_data));
-		inode->i_mapping = dev->dev_mapping;
-		filp->f_mapping = dev->dev_mapping;
-		mutex_unlock(&dev->struct_mutex);
+	if (retcode)
+		goto err_undo;
+	atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
+	if (need_setup) {
+		retcode = drm_setup(dev);
+		if (retcode)
+			goto err_undo;
 	}
+	return 0;
 
+err_undo:
+	mutex_lock(&dev->struct_mutex);
+	filp->f_mapping = old_mapping;
+	inode->i_mapping = old_mapping;
+	iput(container_of(dev->dev_mapping, struct inode, i_data));
+	dev->dev_mapping = old_mapping;
+	mutex_unlock(&dev->struct_mutex);
+	dev->open_count--;
 	return retcode;
 }
 EXPORT_SYMBOL(drm_open);