XArray: Fix xas_next() with a single entry at 0
If there is only a single entry at 0, the first time we call xas_next(),
we return the entry. Unfortunately, all subsequent times we call
xas_next(), we also return the entry at 0 instead of noticing that the
xa_index is now greater than zero. This broke find_get_pages_contig().
Fixes: 64d3e9a9e0cc ("xarray: Step through an XArray")
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
diff --git a/lib/xarray.c b/lib/xarray.c
index 446b956..1237c21 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -994,6 +994,8 @@ void *__xas_prev(struct xa_state *xas)
if (!xas_frozen(xas->xa_node))
xas->xa_index--;
+ if (!xas->xa_node)
+ return set_bounds(xas);
if (xas_not_node(xas->xa_node))
return xas_load(xas);
@@ -1031,6 +1033,8 @@ void *__xas_next(struct xa_state *xas)
if (!xas_frozen(xas->xa_node))
xas->xa_index++;
+ if (!xas->xa_node)
+ return set_bounds(xas);
if (xas_not_node(xas->xa_node))
return xas_load(xas);