Add buddy_get_next_off_*

src/buddy.h

@@ -298,6 +298,7 @@ struct i_wait {
 #define I_WAIT_MAGIC		0x7f6303bc
 	uint8_t			alloced; // how many of n
 	uint8_t			finid;
+	uint8_t			next;
 	enum i_wait_state		state;
 	VTAILQ_ENTRY(buddy_reqs)	list;
 	pthread_mutex_t		wait_mtx;
@@ -524,6 +525,7 @@ BUDDYF(take_ptr_extent)(buddy_t *buddy, const struct buddy_ptr_extent *rs,
 		.magic = I_WAIT_MAGIC,					\
 		.alloced = 0,						\
 		.finid = 0,						\
+		.next = 0,						\
 		.state = IW_ARMED,					\
 		.list = { NULL },					\
 		.wait_mtx = PTHREAD_MUTEX_INITIALIZER,			\
@@ -826,6 +828,17 @@ buddy_get_off_extent(const struct buddy_reqs *reqs, uint8_t n)
 
 	return (_buddy_get_off_extent(reqs, n));
 }
+
+static inline struct buddy_off_extent
+buddy_get_next_off_extent(struct buddy_reqs *reqs)
+{
+
+	CHECK_OBJ_NOTNULL(reqs, BUDDY_REQS_MAGIC);
+	if (reqs->i_wait.next == reqs->i_wait.finid)
+		return (buddy_off_extent_nil);
+	return (buddy_get_off_extent(reqs, reqs->i_wait.next++));
+}
+
 #endif
 
 static inline struct buddy_ptr_extent
@@ -861,6 +874,16 @@ buddy_get_off_page(const struct buddy_reqs *reqs, uint8_t n)
 {
 	return (_buddy_get_off_page(reqs, n));
 }
+
+static inline struct buddy_off_page
+buddy_get_next_off_page(struct buddy_reqs *reqs)
+{
+
+	CHECK_OBJ_NOTNULL(reqs, BUDDY_REQS_MAGIC);
+	if (reqs->i_wait.next == reqs->i_wait.finid)
+		return (buddy_off_page_nil);
+	return (buddy_get_off_page(reqs, reqs->i_wait.next++));
+}
 #endif
 
 static inline struct buddy_ptr_page