[PATCH v12 04/22] vfio: Common function to increment container_users

From: Kirti Wankhede
Date: Mon Nov 14 2016 - 10:41:45 EST


This change rearrange functions to have common function to increment
container_users

Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
Reviewed-by: Jike Song <jike.song@xxxxxxxxx>

Change-Id: I8bdeb352bc8439b107ffd519480fd4dc238677f2
---
drivers/vfio/vfio.c | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 23bc86c1d05d..2e83bdf007fe 100644
--- 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);

--
2.7.0