[Qemu-devel] [PATCH v9 03/12] vfio: Rearrange functions to get vfio_group from dev

[Kirti Wankhede]

Rearrange functions to have common function to increment container_users.

Signed-off-by: Kirti Wankhede <address@hidden>
Signed-off-by: Neo Jia <address@hidden>
Change-Id: I1f93262bdbab75094bc24b087b29da35ba70c4c6
---
 drivers/vfio/vfio.c | 57 ++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index d1d70e0b011b..2e83bdf007fe 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -480,6 +480,21 @@ static struct vfio_group *vfio_group_get_from_minor(int 
minor)
        return group;
 }
 
+static struct vfio_group *vfio_group_get_from_dev(struct device *dev)
+{
+       struct iommu_group *iommu_group;
+       struct vfio_group *group;
+
+       iommu_group = iommu_group_get(dev);
+       if (!iommu_group)
+               return NULL;
+
+       group = vfio_group_get_from_iommu(iommu_group);
+       iommu_group_put(iommu_group);
+
+       return group;
+}
+
 /**
  * Device objects - create, release, get, put, search
  */
@@ -811,16 +826,10 @@ EXPORT_SYMBOL_GPL(vfio_add_group_dev);
  */
 struct vfio_device *vfio_device_get_from_dev(struct device *dev)
 {
-       struct iommu_group *iommu_group;
        struct vfio_group *group;
        struct vfio_device *device;
 
-       iommu_group = iommu_group_get(dev);
-       if (!iommu_group)
-               return NULL;
-
-       group = vfio_group_get_from_iommu(iommu_group);
-       iommu_group_put(iommu_group);
+       group = vfio_group_get_from_dev(dev);
        if (!group)
                return NULL;
 
@@ -1376,6 +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)
@@ -1685,23 +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);
 
-- 
2.7.0