1 files changed, 41 insertions, 37 deletions
diff --git a/lib/xarray.c b/lib/xarray.c
index 32d4bac8c94c..116e9286c64e 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -125,19 +125,20 @@ static inline void node_mark_all(struct xa_node *node, xa_mark_t mark)
  */
 static void xas_squash_marks(const struct xa_state *xas)
 {
-	unsigned int mark = 0;
+	xa_mark_t mark = 0;
 	unsigned int limit = xas->xa_offset + xas->xa_sibs + 1;
 
-	if (!xas->xa_sibs)
-		return;
+	for (;;) {
+		unsigned long *marks = node_marks(xas->xa_node, mark);
 
-	do {
-		unsigned long *marks = xas->xa_node->marks[mark];
-		if (find_next_bit(marks, limit, xas->xa_offset + 1) == limit)
-			continue;
-		__set_bit(xas->xa_offset, marks);
-		bitmap_clear(marks, xas->xa_offset + 1, xas->xa_sibs);
-	} while (mark++ != (__force unsigned)XA_MARK_MAX);
+		if (find_next_bit(marks, limit, xas->xa_offset + 1) != limit) {
+			__set_bit(xas->xa_offset, marks);
+			bitmap_clear(marks, xas->xa_offset + 1, xas->xa_sibs);
+		}
+		if (mark == XA_MARK_MAX)
+			break;
+		mark_inc(mark);
+	}
 }
 
 /* extracts the offset within this node from the index */
@@ -435,6 +436,11 @@ static unsigned long max_index(void *entry)
 	return (XA_CHUNK_SIZE << xa_to_node(entry)->shift) - 1;
 }
 
+static inline void *xa_zero_to_null(void *entry)
+{
+	return xa_is_zero(entry) ? NULL : entry;
+}
+
 static void xas_shrink(struct xa_state *xas)
 {
 	struct xarray *xa = xas->xa;
@@ -451,8 +457,8 @@ static void xas_shrink(struct xa_state *xas)
 			break;
 		if (!xa_is_node(entry) && node->shift)
 			break;
-		if (xa_is_zero(entry) && xa_zero_busy(xa))
-			entry = NULL;
+		if (xa_zero_busy(xa))
+			entry = xa_zero_to_null(entry);
 		xas->xa_node = XAS_BOUNDS;
 
 		RCU_INIT_POINTER(xa->xa_head, entry);
@@ -1022,7 +1028,7 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order,
 	unsigned int mask = xas->xa_sibs;
 
 	/* XXX: no support for splitting really large entries yet */
-	if (WARN_ON(xas->xa_shift + 2 * XA_CHUNK_SHIFT < order))
+	if (WARN_ON(xas->xa_shift + 2 * XA_CHUNK_SHIFT <= order))
 		goto nomem;
 	if (xas->xa_shift + XA_CHUNK_SHIFT > order)
 		return;
@@ -1147,6 +1153,7 @@ void xas_pause(struct xa_state *xas)
 			if (!xa_is_sibling(xa_entry(xas->xa, node, offset)))
 				break;
 		}
+		xas->xa_index &= ~0UL << node->shift;
 		xas->xa_index += (offset - xas->xa_offset) << node->shift;
 		if (xas->xa_index == 0)
 			xas->xa_node = XAS_BOUNDS;
@@ -1382,6 +1389,8 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
 		entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
 		if (!entry && !(xa_track_free(xas->xa) && mark == XA_FREE_MARK))
 			continue;
+		if (xa_is_sibling(entry))
+			continue;
 		if (!xa_is_node(entry))
 			return entry;
 		xas->xa_node = xa_to_node(entry);
@@ -1474,9 +1483,7 @@ void *xa_load(struct xarray *xa, unsigned long index)
 
 	rcu_read_lock();
 	do {
-		entry = xas_load(&xas);
-		if (xa_is_zero(entry))
-			entry = NULL;
+		entry = xa_zero_to_null(xas_load(&xas));
 	} while (xas_retry(&xas, entry));
 	rcu_read_unlock();
 
@@ -1486,8 +1493,6 @@ EXPORT_SYMBOL(xa_load);
 
 static void *xas_result(struct xa_state *xas, void *curr)
 {
-	if (xa_is_zero(curr))
-		return NULL;
 	if (xas_error(xas))
 		curr = xas->xa_node;
 	return curr;
@@ -1508,7 +1513,7 @@ static void *xas_result(struct xa_state *xas, void *curr)
 void *__xa_erase(struct xarray *xa, unsigned long index)
 {
 	XA_STATE(xas, xa, index);
-	return xas_result(&xas, xas_store(&xas, NULL));
+	return xas_result(&xas, xa_zero_to_null(xas_store(&xas, NULL)));
 }
 EXPORT_SYMBOL(__xa_erase);
 
@@ -1567,7 +1572,7 @@ void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
 			xas_clear_mark(&xas, XA_FREE_MARK);
 	} while (__xas_nomem(&xas, gfp));
 
-	return xas_result(&xas, curr);
+	return xas_result(&xas, xa_zero_to_null(curr));
 }
 EXPORT_SYMBOL(__xa_store);
 
@@ -1600,6 +1605,9 @@ void *xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
 }
 EXPORT_SYMBOL(xa_store);
 
+static inline void *__xa_cmpxchg_raw(struct xarray *xa, unsigned long index,
+			void *old, void *entry, gfp_t gfp);
+
 /**
  * __xa_cmpxchg() - Store this entry in the XArray.
  * @xa: XArray.
@@ -1619,6 +1627,13 @@ EXPORT_SYMBOL(xa_store);
 void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
 			void *old, void *entry, gfp_t gfp)
 {
+	return xa_zero_to_null(__xa_cmpxchg_raw(xa, index, old, entry, gfp));
+}
+EXPORT_SYMBOL(__xa_cmpxchg);
+
+static inline void *__xa_cmpxchg_raw(struct xarray *xa, unsigned long index,
+			void *old, void *entry, gfp_t gfp)
+{
 	XA_STATE(xas, xa, index);
 	void *curr;
 
@@ -1636,7 +1651,6 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
 
 	return xas_result(&xas, curr);
 }
-EXPORT_SYMBOL(__xa_cmpxchg);
 
 /**
  * __xa_insert() - Store this entry in the XArray if no entry is present.
@@ -1656,26 +1670,16 @@ EXPORT_SYMBOL(__xa_cmpxchg);
  */
 int __xa_insert(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
 {
-	XA_STATE(xas, xa, index);
 	void *curr;
+	int errno;
 
-	if (WARN_ON_ONCE(xa_is_advanced(entry)))
-		return -EINVAL;
 	if (!entry)
 		entry = XA_ZERO_ENTRY;
-
-	do {
-		curr = xas_load(&xas);
-		if (!curr) {
-			xas_store(&xas, entry);
-			if (xa_track_free(xa))
-				xas_clear_mark(&xas, XA_FREE_MARK);
-		} else {
-			xas_set_err(&xas, -EBUSY);
-		}
-	} while (__xas_nomem(&xas, gfp));
-
-	return xas_error(&xas);
+	curr = __xa_cmpxchg_raw(xa, index, NULL, entry, gfp);
+	errno = xa_err(curr);
+	if (errno)
+		return errno;
+	return (curr != NULL) ? -EBUSY : 0;
 }
 EXPORT_SYMBOL(__xa_insert);