[PATCH 4.9 082/109] vfio/spapr: Fix missing mutex unlock when creating a window

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexey Kardashevskiy <aik@xxxxxxxxx>


[ Upstream commit 2da64d20a0b20046d688e44f4033efd09157e29d ]

Commit d9c728949ddc ("vfio/spapr: Postpone default window creation")
added an additional exit to the VFIO_IOMMU_SPAPR_TCE_CREATE case and
made it possible to return from tce_iommu_ioctl() without unlocking
container->lock; this fixes the issue.

Fixes: d9c728949ddc ("vfio/spapr: Postpone default window creation")
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/vfio/vfio_iommu_spapr_tce.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -1123,12 +1123,11 @@ static long tce_iommu_ioctl(void *iommu_
 		mutex_lock(&container->lock);
 
 		ret = tce_iommu_create_default_window(container);
-		if (ret)
-			return ret;
-
-		ret = tce_iommu_create_window(container, create.page_shift,
-				create.window_size, create.levels,
-				&create.start_addr);
+		if (!ret)
+			ret = tce_iommu_create_window(container,
+					create.page_shift,
+					create.window_size, create.levels,
+					&create.start_addr);
 
 		mutex_unlock(&container->lock);