Merge tag 'xarray-5.12' of git://git.infradead.org/users/willy/xarray

Pull XArray fixes from Matthew Wilcox:
 "My apologies for the lateness of this. I had a bug reported in the
  test suite, and when I started working on it, I realised I had two
  fixes sitting in the xarray tree since last November. Anyway,
  everything here is fixes, apart from adding xa_limit_16b. The test
  suite passes.

  Summary:

   - Fix a bug when splitting to a non-zero order

   - Documentation fix

   - Add a predefined 16-bit allocation limit

   - Various test suite fixes"

* tag 'xarray-5.12' of git://git.infradead.org/users/willy/xarray:
  idr test suite: Improve reporting from idr_find_test_1
  idr test suite: Create anchor before launching throbber
  idr test suite: Take RCU read lock in idr_find_test_1
  radix tree test suite: Register the main thread with the RCU library
  radix tree test suite: Fix compilation
  XArray: Add xa_limit_16b
  XArray: Fix splitting to non-zero orders
  XArray: Fix split documentation

1 files changed, 6 insertions, 5 deletions

diff --git a/lib/xarray.c b/lib/xarray.c
index 5fa51614802a..f5d8f54907b4 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -987,7 +987,7 @@ static void node_set_marks(struct xa_node *node, unsigned int offset,
  * xas_split_alloc() - Allocate memory for splitting an entry.
  * @xas: XArray operation state.
  * @entry: New entry which will be stored in the array.
- * @order: New entry order.
+ * @order: Current entry order.
  * @gfp: Memory allocation flags.
  *
  * This function should be called before calling xas_split().
@@ -1011,7 +1011,7 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order,
 
 	do {
 		unsigned int i;
-		void *sibling;
+		void *sibling = NULL;
 		struct xa_node *node;
 
 		node = kmem_cache_alloc(radix_tree_node_cachep, gfp);
@@ -1021,7 +1021,7 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order,
 		for (i = 0; i < XA_CHUNK_SIZE; i++) {
 			if ((i & mask) == 0) {
 				RCU_INIT_POINTER(node->slots[i], entry);
-				sibling = xa_mk_sibling(0);
+				sibling = xa_mk_sibling(i);
 			} else {
 				RCU_INIT_POINTER(node->slots[i], sibling);
 			}
@@ -1041,9 +1041,10 @@ EXPORT_SYMBOL_GPL(xas_split_alloc);
  * xas_split() - Split a multi-index entry into smaller entries.
  * @xas: XArray operation state.
  * @entry: New entry to store in the array.
- * @order: New entry order.
+ * @order: Current entry order.
  *
- * The value in the entry is copied to all the replacement entries.
+ * The size of the new entries is set in @xas.  The value in @entry is
+ * copied to all the replacement entries.
  *
  * Context: Any context.  The caller should hold the xa_lock.
  */