vfio: Do not open code the group list search in vfio_create_group()

Split vfio_group_get_from_iommu() into __vfio_group_get_from_iommu() so
that vfio_create_group() can call it to consolidate this duplicated code.

Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v3-2fdfe4ca2cc6+18c-vfio_group_cdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 4ce7e9fe43af9505d66eefc194eb059841a136ec..513fb5a4c102db8ca536e68b054329ecff4eae1b 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -340,10 +340,35 @@ static void vfio_group_unlock_and_free(struct vfio_group *group)
 /**
  * Group objects - create, release, get, put, search
  */
+static struct vfio_group *
+__vfio_group_get_from_iommu(struct iommu_group *iommu_group)
+{
+       struct vfio_group *group;
+
+       list_for_each_entry(group, &vfio.group_list, vfio_next) {
+               if (group->iommu_group == iommu_group) {
+                       vfio_group_get(group);
+                       return group;
+               }
+       }
+       return NULL;
+}
+
+static struct vfio_group *
+vfio_group_get_from_iommu(struct iommu_group *iommu_group)
+{
+       struct vfio_group *group;
+
+       mutex_lock(&vfio.group_lock);
+       group = __vfio_group_get_from_iommu(iommu_group);
+       mutex_unlock(&vfio.group_lock);
+       return group;
+}
+
 static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
                enum vfio_group_type type)
 {
-       struct vfio_group *group, *tmp;
+       struct vfio_group *group, *existing_group;
        struct device *dev;
        int ret, minor;
 
@@ -373,12 +398,10 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
        mutex_lock(&vfio.group_lock);
 
        /* Did we race creating this group? */
-       list_for_each_entry(tmp, &vfio.group_list, vfio_next) {
-               if (tmp->iommu_group == iommu_group) {
-                       vfio_group_get(tmp);
-                       vfio_group_unlock_and_free(group);
-                       return tmp;
-               }
+       existing_group = __vfio_group_get_from_iommu(iommu_group);
+       if (existing_group) {
+               vfio_group_unlock_and_free(group);
+               return existing_group;
        }
 
        minor = vfio_alloc_group_minor(group);
@@ -441,24 +464,6 @@ static void vfio_group_get(struct vfio_group *group)
        kref_get(&group->kref);
 }
 
-static
-struct vfio_group *vfio_group_get_from_iommu(struct iommu_group *iommu_group)
-{
-       struct vfio_group *group;
-
-       mutex_lock(&vfio.group_lock);
-       list_for_each_entry(group, &vfio.group_list, vfio_next) {
-               if (group->iommu_group == iommu_group) {
-                       vfio_group_get(group);
-                       mutex_unlock(&vfio.group_lock);
-                       return group;
-               }
-       }
-       mutex_unlock(&vfio.group_lock);
-
-       return NULL;
-}
-
 static struct vfio_group *vfio_group_get_from_minor(int minor)
 {
        struct vfio_group *group;