vm_pager: add methods for page insertion and removal notifications

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D37097

3 files changed, 30 insertions, 0 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 4f97b84ee205..20238e0ad807 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -1483,6 +1483,7 @@ vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
 		return (1);
 	}
 	vm_page_insert_radixdone(m, object, mpred);
+	vm_pager_page_inserted(object, m);
 	return (0);
 }
 
@@ -1557,6 +1558,8 @@ vm_page_object_remove(vm_page_t m)
 	if ((m->a.flags & PGA_SWAP_FREE) != 0)
 		vm_pager_page_unswapped(m);
 
+	vm_pager_page_removed(object, m);
+
 	m->object = NULL;
 	mrem = vm_radix_remove(&object->rtree, m->pindex);
 	KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
@@ -1879,6 +1882,7 @@ vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
 
 	vm_page_insert_radixdone(m, new_object, mpred);
 	vm_page_dirty(m);
+	vm_pager_page_inserted(new_object, m);
 	return (0);
 }
 
diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c
index cc0be174987d..36ce380dedbc 100644
--- a/sys/vm/vm_pager.c
+++ b/sys/vm/vm_pager.c
@@ -430,6 +430,8 @@ vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type)
 		FIX(mightbedirty);
 		FIX(getvp);
 		FIX(freespace);
+		FIX(page_inserted);
+		FIX(page_removed);
 #undef FIX
 	}
 	pagertab[res] = ops;	/* XXXKIB should be rel, but acq is too much */
diff --git a/sys/vm/vm_pager.h b/sys/vm/vm_pager.h
index e332231a77c6..5917bf651760 100644
--- a/sys/vm/vm_pager.h
+++ b/sys/vm/vm_pager.h
@@ -69,6 +69,8 @@ typedef void pgo_getvp_t(vm_object_t object, struct vnode **vpp,
     bool *vp_heldp);
 typedef void pgo_freespace_t(vm_object_t object, vm_pindex_t start,
     vm_size_t size);
+typedef void pgo_page_inserted_t(vm_object_t object, vm_page_t m);
+typedef void pgo_page_removed_t(vm_object_t object, vm_page_t m);
 
 struct pagerops {
 	int			pgo_kvme_type;
@@ -87,6 +89,8 @@ struct pagerops {
 	pgo_mightbedirty_t	*pgo_mightbedirty;
 	pgo_getvp_t		*pgo_getvp;
 	pgo_freespace_t		*pgo_freespace;
+	pgo_page_inserted_t	*pgo_page_inserted;
+	pgo_page_removed_t	*pgo_page_removed;
 };
 
 extern const struct pagerops defaultpagerops;
@@ -249,6 +253,26 @@ vm_pager_freespace(vm_object_t object, vm_pindex_t start,
 		method(object, start, size);
 }
 
+static __inline void
+vm_pager_page_inserted(vm_object_t object, vm_page_t m)
+{
+	pgo_page_inserted_t *method;
+
+	method = pagertab[object->type]->pgo_page_inserted;
+	if (method != NULL)
+		method(object, m);
+}
+
+static __inline void
+vm_pager_page_removed(vm_object_t object, vm_page_t m)
+{
+	pgo_page_removed_t *method;
+
+	method = pagertab[object->type]->pgo_page_removed;
+	if (method != NULL)
+		method(object, m);
+}
+
 int vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type);
 void vm_pager_free_dyn_type(objtype_t type);