KVM: VFIO: use mutex guard in kvm_vfio_file_set_spapr_tce()

Use a mutex guard to hold a lock for the entirety of the function, which
removes the need for a goto (whose label even has a misleading name
since 8152f8201088 ("fdget(), more trivial conversions"))

Signed-off-by: Carlos López <clopez@suse.de>
Reviewed-by: Alex Williamson <alex@shazbot.org>
Link: https://patch.msgid.link/20260313122040.1413091-5-clopez@suse.de
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 2c91bad3333bb81de0d9edf94ce8547b7ff006a7..e0d621567dbf6ee7bc05b7e19d3411561a6e0069 100644 (file)
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -216,7 +216,6 @@ static int kvm_vfio_file_set_spapr_tce(struct kvm_device *dev,
        struct kvm_vfio_spapr_tce param;
        struct kvm_vfio *kv = dev->private;
        struct kvm_vfio_file *kvf;
-       int ret;
 
        if (copy_from_user(&param, arg, sizeof(struct kvm_vfio_spapr_tce)))
                return -EFAULT;
@@ -225,9 +224,7 @@ static int kvm_vfio_file_set_spapr_tce(struct kvm_device *dev,
        if (fd_empty(f))
                return -EBADF;
 
-       ret = -ENOENT;
-
-       mutex_lock(&kv->lock);
+       guard(mutex)(&kv->lock);
 
        list_for_each_entry(kvf, &kv->file_list, node) {
                if (kvf->file != fd_file(f))
@@ -235,20 +232,15 @@ static int kvm_vfio_file_set_spapr_tce(struct kvm_device *dev,
 
                if (!kvf->iommu_group) {
                        kvf->iommu_group = kvm_vfio_file_iommu_group(kvf->file);
-                       if (WARN_ON_ONCE(!kvf->iommu_group)) {
-                               ret = -EIO;
-                               goto err_fdput;
-                       }
+                       if (WARN_ON_ONCE(!kvf->iommu_group))
+                               return -EIO;
                }
 
-               ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
-                                                      kvf->iommu_group);
-               break;
+               return kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
+                                                       kvf->iommu_group);
        }
 
-err_fdput:
-       mutex_unlock(&kv->lock);
-       return ret;
+       return -ENOENT;
 }
 #endif