radix tree test suite: align kmem_cache_alloc_bulk() with kernel behavior.

When kmem_cache_alloc_bulk() fails to allocate, leave the freed pointers
in the array. This enables a more accurate simulation of the kernel's
behavior and allows for testing potential double-free scenarios.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Peng Zhang <[e-mail]>
Reviewed-by: Liam R. Howlett <[e-mail]>
Cc: Christian Brauner <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: Mateusz Guzik <[e-mail]>
Cc: Mathieu Desnoyers <[e-mail]>
Cc: Matthew Wilcox <[e-mail]>
Cc: Michael S. Tsirkin <[e-mail]>
Cc: Mike Christie <[e-mail]>
Cc: Nicholas Piggin <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Suren Baghdasaryan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

tools/testing/radix-tree/linux.c

···
 	return p;
 }
 
-void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
+void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
 {
 	assert(objp);
-	uatomic_dec(&nr_allocated);
-	uatomic_dec(&cachep->nr_allocated);
-	if (kmalloc_verbose)
-		printf("Freeing %p to slab\n", objp);
 	if (cachep->nr_objs > 10 || cachep->align) {
 		memset(objp, POISON_FREE, cachep->size);
 		free(objp);
···
 		node->parent = cachep->objs;
 		cachep->objs = node;
 	}
+}
+
+void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
+{
+	uatomic_dec(&nr_allocated);
+	uatomic_dec(&cachep->nr_allocated);
+	if (kmalloc_verbose)
+		printf("Freeing %p to slab\n", objp);
+	__kmem_cache_free_locked(cachep, objp);
 }
 
 void kmem_cache_free(struct kmem_cache *cachep, void *objp)
···
 	if (kmalloc_verbose)
 		pr_debug("Bulk alloc %lu\n", size);
 
-	if (!(gfp & __GFP_DIRECT_RECLAIM)) {
-		if (cachep->non_kernel < size)
-			return 0;
-
-		cachep->non_kernel -= size;
-	}
-
 	pthread_mutex_lock(&cachep->lock);
 	if (cachep->nr_objs >= size) {
 		struct radix_tree_node *node;
 
 		for (i = 0; i < size; i++) {
+			if (!(gfp & __GFP_DIRECT_RECLAIM)) {
+				if (!cachep->non_kernel)
+					break;
+				cachep->non_kernel--;
+			}
+
 			node = cachep->objs;
 			cachep->nr_objs--;
 			cachep->objs = node->parent;
···
 	} else {
 		pthread_mutex_unlock(&cachep->lock);
 		for (i = 0; i < size; i++) {
+			if (!(gfp & __GFP_DIRECT_RECLAIM)) {
+				if (!cachep->non_kernel)
+					break;
+				cachep->non_kernel--;
+			}
+
 			if (cachep->align) {
 				posix_memalign(&p[i], cachep->align,
 					       cachep->size);
 			} else {
 				p[i] = malloc(cachep->size);
+				if (!p[i])
+					break;
 			}
 			if (cachep->ctor)
 				cachep->ctor(p[i]);
 			else if (gfp & __GFP_ZERO)
 				memset(p[i], 0, cachep->size);
 		}
+	}
+
+	if (i < size) {
+		size = i;
+		pthread_mutex_lock(&cachep->lock);
+		for (i = 0; i < size; i++)
+			__kmem_cache_free_locked(cachep, p[i]);
+		pthread_mutex_unlock(&cachep->lock);
+		return 0;
 	}
 
 	for (i = 0; i < size; i++) {