vfio: get rid of open-coding kref_put_mutex

Al Viro · Al Viro · commit 6d2cd3ce815b · 2012-08-22T10:25:19.000-04:00
Acked-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
@@ -264,6 +264,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
 	return group;
 }
 
+/* called with vfio.group_lock held */
 static void vfio_group_release(struct kref *kref)
 {
 	struct vfio_group *group = container_of(kref, struct vfio_group, kref);
@@ -287,13 +288,7 @@ static void vfio_group_release(struct kref *kref)
 
 static void vfio_group_put(struct vfio_group *group)
 {
-	mutex_lock(&vfio.group_lock);
-	/*
-	 * Release needs to unlock to unregister the notifier, so only
-	 * unlock if not released.
-	 */
-	if (!kref_put(&group->kref, vfio_group_release))
-		mutex_unlock(&vfio.group_lock);
+	kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock);
 }
 
 /* Assume group_lock or group reference is held */

Original file line number	Diff line number	Diff line change
`@@ -264,6 +264,7 @@ static struct vfio_group vfio_create_group(struct iommu_group iommu_group)`
`264`	`264`	`return group;`
`265`	`265`	`}`
`266`	`266`
	`267`	`+/* called with vfio.group_lock held */`
`267`	`268`	`static void vfio_group_release(struct kref *kref)`
`268`	`269`	`{`
`269`	`270`	`struct vfio_group *group = container_of(kref, struct vfio_group, kref);`
`@@ -287,13 +288,7 @@ static void vfio_group_release(struct kref *kref)`
`287`	`288`
`288`	`289`	`static void vfio_group_put(struct vfio_group *group)`
`289`	`290`	`{`
`290`		`- mutex_lock(&vfio.group_lock);`
`291`		`- /*`
`292`		`- * Release needs to unlock to unregister the notifier, so only`
`293`		`- * unlock if not released.`
`294`		`- */`
`295`		`- if (!kref_put(&group->kref, vfio_group_release))`
`296`		`- mutex_unlock(&vfio.group_lock);`
	`291`	`+ kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock);`
`297`	`292`	`}`
`298`	`293`
`299`	`294`	`/* Assume group_lock or group reference is held */`