XArray: Fix xa_alloc when id exceeds max

Specifying a starting ID greater than the maximum ID isn't something
attempted very often, but it should fail.  It was succeeding due to
xas_find_marked() returning the wrong error state, so add tests for
both xa_alloc() and xas_find_marked().

Fixes: b803b42823d0 ("xarray: Add XArray iterators")
Signed-off-by: Matthew Wilcox <willy@infradead.org>

diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 6f09c845187ebfd018575586634ceac613fbd6f1..4676c0a1eeca0f7f7c559176b2c580cedcccce6d 100644 (file)
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -633,6 +633,15 @@ static noinline void check_xa_alloc(void)
                                GFP_KERNEL) != -ENOSPC);
        XA_BUG_ON(&xa0, id != 0xffffffffU);
        xa_destroy(&xa0);
+
+       id = 10;
+       XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, 5, xa_mk_index(id),
+                               GFP_KERNEL) != -ENOSPC);
+       XA_BUG_ON(&xa0, xa_store_index(&xa0, 3, GFP_KERNEL) != 0);
+       XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, 5, xa_mk_index(id),
+                               GFP_KERNEL) != -ENOSPC);
+       xa_erase_index(&xa0, 3);
+       XA_BUG_ON(&xa0, !xa_empty(&xa0));
 }
 
 static noinline void __check_store_iter(struct xarray *xa, unsigned long start,
@@ -822,10 +831,34 @@ static noinline void check_find_2(struct xarray *xa)
        xa_destroy(xa);
 }
 
+static noinline void check_find_3(struct xarray *xa)
+{
+       XA_STATE(xas, xa, 0);
+       unsigned long i, j, k;
+       void *entry;
+
+       for (i = 0; i < 100; i++) {
+               for (j = 0; j < 100; j++) {
+                       for (k = 0; k < 100; k++) {
+                               xas_set(&xas, j);
+                               xas_for_each_marked(&xas, entry, k, XA_MARK_0)
+                                       ;
+                               if (j > k)
+                                       XA_BUG_ON(xa,
+                                               xas.xa_node != XAS_RESTART);
+                       }
+               }
+               xa_store_index(xa, i, GFP_KERNEL);
+               xa_set_mark(xa, i, XA_MARK_0);
+       }
+       xa_destroy(xa);
+}
+
 static noinline void check_find(struct xarray *xa)
 {
        check_find_1(xa);
        check_find_2(xa);
+       check_find_3(xa);
        check_multi_find(xa);
        check_multi_find_2(xa);
 }

diff --git a/lib/xarray.c b/lib/xarray.c
index bbacca576593613f25cf107485f3cd8a89896d0b..5f3f9311de893a2975990060f5dfae6a6fb3d462 100644 (file)
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1131,7 +1131,7 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
                entry = xa_head(xas->xa);
                xas->xa_node = NULL;
                if (xas->xa_index > max_index(entry))
-                       goto bounds;
+                       goto out;
                if (!xa_is_node(entry)) {
                        if (xa_marked(xas->xa, mark))
                                return entry;
@@ -1180,11 +1180,9 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
        }
 
 out:
-       if (!max)
+       if (xas->xa_index > max)
                goto max;
-bounds:
-       xas->xa_node = XAS_BOUNDS;
-       return NULL;
+       return set_bounds(xas);
 max:
        xas->xa_node = XAS_RESTART;
        return NULL;