maple_tree: Clean up after bulk allocation failure in mas_alloc_nodes()

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 6393be9d9230de1ba06d0d57cf2b432689fded0d..3c78e63efaecc215222df598800f49a5b9a0a091 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1206,6 +1206,8 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
        unsigned long success = allocated;
        unsigned int requested = mas_alloc_req(mas);
        unsigned int count;
+       void **slots = NULL;
+       unsigned int max_req = 0;
 
        if (!requested)
                return;
@@ -1214,7 +1216,7 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
        if (!allocated || mas->alloc->node_count == MAPLE_ALLOC_SLOTS - 1) {
                node = (struct maple_alloc *)mt_alloc_one(gfp);
                if (!node)
-                       goto nomem;
+                       goto nomem_one;
 
                if (allocated)
                        node->slot[0] = mas->alloc;
@@ -1226,20 +1228,20 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
 
        node = mas->alloc;
        while (requested) {
-               void **slots = (void **)&node->slot;
-               unsigned int max_req = MAPLE_NODE_SLOTS - 1;
-
+               max_req = MAPLE_NODE_SLOTS - 1;
                if (node->slot[0]) {
                        unsigned int offset = node->node_count + 1;
 
                        slots = (void **)&node->slot[offset];
                        max_req -= offset;
+               } else {
+                       slots = (void **)&node->slot;
                }
 
-               count = mt_alloc_bulk(gfp, min(requested, max_req),
-                                     slots);
+               max_req = min(requested, max_req);
+               count = mt_alloc_bulk(gfp, max_req, slots);
                if (!count)
-                       goto nomem;
+                       goto nomem_bulk;
 
                node->node_count += count;
                /* zero indexed. */
@@ -1253,7 +1255,11 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
        }
        mas->alloc->total = success;
        return;
-nomem:
+
+nomem_bulk:
+       /* Clean up potential freed allocations on bulk failure */
+       memset(slots, 0, max_req * sizeof(unsigned long));
+nomem_one:
        mas_set_alloc_req(mas, requested);
        if (mas->alloc && !(((unsigned long)mas->alloc & 0x1)))
                mas->alloc->total = success;