XArray: Fix xa_reserve for 2-byte aligned entries
If we reserve index 0, the next entry to be stored there might be 2-byte
aligned. That means we have to create the root xa_node at the time of
reserving the initial entry.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
diff --git a/lib/xarray.c b/lib/xarray.c
index 2cc3798..6be3acb 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -767,10 +767,12 @@
void *first, *next;
bool value = xa_is_value(entry);
- if (entry)
- first = xas_create(xas, !xa_is_node(entry));
- else
+ if (entry) {
+ bool allow_root = !xa_is_node(entry) && !xa_is_zero(entry);
+ first = xas_create(xas, allow_root);
+ } else {
first = xas_load(xas);
+ }
if (xas_invalid(xas))
return first;