iommu: Tidy the control flow in iommu_group_store_type()

Use a normal "goto unwind" instead of trying to be clever with checking
!ret and manually managing the unlock.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/17-v5-1b99ae392328+44574-iommu_err_unwind_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 1aaf3eb6fccaf3bfd0102dc65e590ab1c4d79ca5..9e0228ef612b85dee3c664a09c928020fca3c844 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2940,6 +2940,7 @@ out_free:
 static ssize_t iommu_group_store_type(struct iommu_group *group,
                                      const char *buf, size_t count)
 {
+       struct group_device *gdev;
        int ret, req_type;
 
        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
@@ -2964,20 +2965,23 @@ static ssize_t iommu_group_store_type(struct iommu_group *group,
        if (req_type == IOMMU_DOMAIN_DMA_FQ &&
            group->default_domain->type == IOMMU_DOMAIN_DMA) {
                ret = iommu_dma_init_fq(group->default_domain);
-               if (!ret)
-                       group->default_domain->type = IOMMU_DOMAIN_DMA_FQ;
-               mutex_unlock(&group->mutex);
+               if (ret)
+                       goto out_unlock;
 
-               return ret ?: count;
+               group->default_domain->type = IOMMU_DOMAIN_DMA_FQ;
+               ret = count;
+               goto out_unlock;
        }
 
        /* Otherwise, ensure that device exists and no driver is bound. */
        if (list_empty(&group->devices) || group->owner_cnt) {
-               mutex_unlock(&group->mutex);
-               return -EPERM;
+               ret = -EPERM;
+               goto out_unlock;
        }
 
        ret = iommu_setup_default_domain(group, req_type);
+       if (ret)
+               goto out_unlock;
 
        /*
         * Release the mutex here because ops->probe_finalize() call-back of
@@ -2988,13 +2992,12 @@ static ssize_t iommu_group_store_type(struct iommu_group *group,
        mutex_unlock(&group->mutex);
 
        /* Make sure dma_ops is appropriatley set */
-       if (!ret) {
-               struct group_device *gdev;
-
-               for_each_group_device(group, gdev)
-                       iommu_group_do_probe_finalize(gdev->dev);
-       }
+       for_each_group_device(group, gdev)
+               iommu_group_do_probe_finalize(gdev->dev);
+       return count;
 
+out_unlock:
+       mutex_unlock(&group->mutex);
        return ret ?: count;
 }