Add pgo_mightbedirty method

Used to implement vm_object_mightbedirty()

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D30070

sys/vm/swap_pager.c

@@ -434,6 +434,7 @@ static void	swap_pager_update_writecount(vm_object_t object,
 static void	swap_pager_release_writecount(vm_object_t object,
     vm_offset_t start, vm_offset_t end);
 static void	swap_pager_set_writeable_dirty(vm_object_t object);
+static bool	swap_pager_mightbedirty(vm_object_t object);
 
 struct pagerops swappagerops = {
 	.pgo_init =	swap_pager_init,	/* early system initialization of pager	*/
@@ -447,6 +448,7 @@ struct pagerops swappagerops = {
 	.pgo_update_writecount = swap_pager_update_writecount,
 	.pgo_release_writecount = swap_pager_release_writecount,
 	.pgo_set_writeable_dirty = swap_pager_set_writeable_dirty,
+	.pgo_mightbedirty = swap_pager_mightbedirty,
 };
 
 /*
@@ -3132,3 +3134,11 @@ swap_pager_set_writeable_dirty(vm_object_t object)
 	if ((object->flags & OBJ_TMPFS_NODE) != 0)
 		vm_object_set_writeable_dirty_(object);
 }
+
+static bool
+swap_pager_mightbedirty(vm_object_t object)
+{
+	if ((object->flags & OBJ_TMPFS_NODE) != 0)
+		return (vm_object_mightbedirty_(object));
+	return (false);
+}

sys/vm/vm_object.c

@@ -2337,6 +2337,12 @@ vm_object_set_writeable_dirty_(vm_object_t object)
 	atomic_add_int(&object->generation, 1);
 }
 
+bool
+vm_object_mightbedirty_(vm_object_t object)
+{
+	return (object->generation != object->cleangeneration);
+}
+
 /*
  *	vm_object_unwire:
  *

sys/vm/vm_object.h

@@ -330,21 +330,6 @@ vm_object_reserv(vm_object_t object)
 	return (false);
 }
 
-static __inline bool
-vm_object_mightbedirty(vm_object_t object)
-{
-
-	if (object->type != OBJT_VNODE) {
-		if ((object->flags & OBJ_TMPFS_NODE) == 0)
-			return (false);
-#ifdef KASSERT
-		KASSERT(object->type == OBJT_SWAP,
-		    ("TMPFS_NODE obj %p is not swap", object));
-#endif
-	}
-	return (object->generation != object->cleangeneration);
-}
-
 void vm_object_clear_flag(vm_object_t object, u_short bits);
 void vm_object_pip_add(vm_object_t object, short i);
 void vm_object_pip_wakeup(vm_object_t object);
@@ -379,6 +364,8 @@ void vm_object_destroy (vm_object_t);
 void vm_object_terminate (vm_object_t);
 void vm_object_set_writeable_dirty (vm_object_t);
 void vm_object_set_writeable_dirty_(vm_object_t object);
+bool vm_object_mightbedirty(vm_object_t object);
+bool vm_object_mightbedirty_(vm_object_t object);
 void vm_object_init (void);
 int  vm_object_kvme_type(vm_object_t object, struct vnode **vpp);
 void vm_object_madvise(vm_object_t, vm_pindex_t, vm_pindex_t, int);

sys/vm/vm_pager.c

@@ -508,3 +508,13 @@ vm_object_set_writeable_dirty(vm_object_t object)
 		method(object);
 }
 
+bool
+vm_object_mightbedirty(vm_object_t object)
+{
+	pgo_mightbedirty_t *method;
+
+	method = pagertab[object->type]->pgo_mightbedirty;
+	if (method == NULL)
+		return (false);
+	return (method(object));
+}

sys/vm/vm_pager.h

@@ -63,6 +63,7 @@ typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t,
 typedef void pgo_pageunswapped_t(vm_page_t);
 typedef void pgo_writecount_t(vm_object_t, vm_offset_t, vm_offset_t);
 typedef void pgo_set_writeable_dirty_t(vm_object_t);
+typedef bool pgo_mightbedirty_t(vm_object_t);
 
 struct pagerops {
 	pgo_init_t		*pgo_init;		/* Initialize pager. */
@@ -77,6 +78,7 @@ struct pagerops {
 	pgo_writecount_t	*pgo_update_writecount;
 	pgo_writecount_t	*pgo_release_writecount;
 	pgo_set_writeable_dirty_t *pgo_set_writeable_dirty;
+	pgo_mightbedirty_t	*pgo_mightbedirty;
 };
 
 extern struct pagerops defaultpagerops;

sys/vm/vnode_pager.c

@@ -116,6 +116,7 @@ struct pagerops vnodepagerops = {
 	.pgo_update_writecount = vnode_pager_update_writecount,
 	.pgo_release_writecount = vnode_pager_release_writecount,
 	.pgo_set_writeable_dirty = vm_object_set_writeable_dirty_,
+	.pgo_mightbedirty = vm_object_mightbedirty_,
 };
 
 static struct domainset *vnode_domainset = NULL;