vfio: Common function to increment container_users

This change rearrange functions to have common function to increment
container_users

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 23bc86c1d05dda3185ee78b80213ad5eb418110b..2e83bdf007fea3ec6fb500acba339c1572e0f982 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1385,6 +1385,23 @@ static bool vfio_group_viable(struct vfio_group *group)
                                         group, vfio_dev_viable) == 0);
 }
 
+static int vfio_group_add_container_user(struct vfio_group *group)
+{
+       if (!atomic_inc_not_zero(&group->container_users))
+               return -EINVAL;
+
+       if (group->noiommu) {
+               atomic_dec(&group->container_users);
+               return -EPERM;
+       }
+       if (!group->container->iommu_driver || !vfio_group_viable(group)) {
+               atomic_dec(&group->container_users);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 static const struct file_operations vfio_device_fops;
 
 static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
@@ -1694,23 +1711,14 @@ static const struct file_operations vfio_device_fops = {
 struct vfio_group *vfio_group_get_external_user(struct file *filep)
 {
        struct vfio_group *group = filep->private_data;
+       int ret;
 
        if (filep->f_op != &vfio_group_fops)
                return ERR_PTR(-EINVAL);
 
-       if (!atomic_inc_not_zero(&group->container_users))
-               return ERR_PTR(-EINVAL);
-
-       if (group->noiommu) {
-               atomic_dec(&group->container_users);
-               return ERR_PTR(-EPERM);
-       }
-
-       if (!group->container->iommu_driver ||
-                       !vfio_group_viable(group)) {
-               atomic_dec(&group->container_users);
-               return ERR_PTR(-EINVAL);
-       }
+       ret = vfio_group_add_container_user(group);
+       if (ret)
+               return ERR_PTR(ret);
 
        vfio_group_get(group);