Move `pgo_fault' handler outside of uvm_fault_lower().

Reduce differences with NetBSD and prepare for `uobj' locking.

No functionnal change. ok chris@, kettenis@

diff --git a/sys/uvm/uvm_fault.c b/sys/uvm/uvm_fault.c
index bd88a60..ffceeb4 100644 (file)
--- a/sys/uvm/uvm_fault.c
+++ b/sys/uvm/uvm_fault.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_fault.c,v 1.115 2021/02/16 09:10:17 mpi Exp $     */
+/*     $OpenBSD: uvm_fault.c,v 1.116 2021/02/23 10:41:59 mpi Exp $     */
 /*     $NetBSD: uvm_fault.c,v 1.51 2000/08/06 00:22:53 thorpej Exp $   */
 
 /*
@@ -598,10 +598,37 @@ uvm_fault(vm_map_t orig_map, vaddr_t vaddr, vm_fault_t fault_type,
                        /* case 1: fault on an anon in our amap */
                        error = uvm_fault_upper(&ufi, &flt, anons, fault_type);
                } else {
-                       /* case 2: fault on backing object or zero fill */
-                       KERNEL_LOCK();
-                       error = uvm_fault_lower(&ufi, &flt, pages, fault_type);
-                       KERNEL_UNLOCK();
+                       struct uvm_object *uobj = ufi.entry->object.uvm_obj;
+
+                       /*
+                        * if the desired page is not shadowed by the amap and
+                        * we have a backing object, then we check to see if
+                        * the backing object would prefer to handle the fault
+                        * itself (rather than letting us do it with the usual
+                        * pgo_get hook).  the backing object signals this by
+                        * providing a pgo_fault routine.
+                        */
+                       if (uobj != NULL && uobj->pgops->pgo_fault != NULL) {
+                               KERNEL_LOCK();
+                               error = uobj->pgops->pgo_fault(&ufi,
+                                   flt.startva, pages, flt.npages,
+                                   flt.centeridx, fault_type, flt.access_type,
+                                   PGO_LOCKED);
+                               KERNEL_UNLOCK();
+
+                               if (error == VM_PAGER_OK)
+                                       error = 0;
+                               else if (error == VM_PAGER_REFAULT)
+                                       error = ERESTART;
+                               else
+                                       error = EACCES;
+                       } else {
+                               /* case 2: fault on backing obj or zero fill */
+                               KERNEL_LOCK();
+                               error = uvm_fault_lower(&ufi, &flt, pages,
+                                   fault_type);
+                               KERNEL_UNLOCK();
+                       }
                }
        }
 
@@ -1055,26 +1082,6 @@ uvm_fault_lower(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
        vaddr_t currva;
        voff_t uoff;
 
-       /*
-        * if the desired page is not shadowed by the amap and we have a
-        * backing object, then we check to see if the backing object would
-        * prefer to handle the fault itself (rather than letting us do it
-        * with the usual pgo_get hook).  the backing object signals this by
-        * providing a pgo_fault routine.
-        */
-       if (uobj != NULL && uobj->pgops->pgo_fault != NULL) {
-               result = uobj->pgops->pgo_fault(ufi, flt->startva, pages,
-                   flt->npages, flt->centeridx, fault_type, flt->access_type,
-                   PGO_LOCKED);
-
-               if (result == VM_PAGER_OK)
-                       return (0);             /* pgo_fault did pmap enter */
-               else if (result == VM_PAGER_REFAULT)
-                       return ERESTART;        /* try again! */
-               else
-                       return (EACCES);
-       }
-
        /*
         * now, if the desired page is not shadowed by the amap and we have
         * a backing object that does not have a special fault routine, then