vfio/type1: Remove the almost unused check in vfio_iommu_type1_unpin_pages

The check i > npage at the end of vfio_iommu_type1_unpin_pages is unused
unless npage < 0, but if npage < 0, this function will return npage, which
should return -EINVAL instead. So let's just check the parameter npage at
the start of the function. By the way, replace unpin_exit with break.

Signed-off-by: Shenming Lu <lushenming@huawei.com>
Message-Id: <20210406135009.1707-1-lushenming@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0485ad8..5fb1bb5 100644 (file)
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -960,7 +960,7 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
        bool do_accounting;
        int i;
 
-       if (!iommu || !user_pfn)
+       if (!iommu || !user_pfn || npage <= 0)
                return -EINVAL;
 
        /* Supported for v2 version only */
@@ -977,13 +977,13 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
                iova = user_pfn[i] << PAGE_SHIFT;
                dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
                if (!dma)
-                       goto unpin_exit;
+                       break;
+
                vfio_unpin_page_external(dma, iova, do_accounting);
        }
 
-unpin_exit:
        mutex_unlock(&iommu->lock);
-       return i > npage ? npage : (i > 0 ? i : -EINVAL);
+       return i > 0 ? i : -EINVAL;
 }
 
 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,