maple_tree: Prefilled sheaf conversion and testing

Use prefilled sheaves instead of bulk allocations. This should speed up
the allocations and the return path of unused allocations.

Remove the push and pop of nodes from the maple state as this is now
handled by the slab layer with sheaves.

Testing has been removed as necessary since the features of the tree
have been reduced.

Signed-off-by: Liam R. Howlett <[email protected]>
Reviewed-by: Suren Baghdasaryan <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>

Author: howlett

include/linux/maple_tree.h

@@ -442,7 +442,8 @@ struct ma_state {
 	struct maple_enode *node;	/* The node containing this entry */
 	unsigned long min;		/* The minimum index of this node - implied pivot min */
 	unsigned long max;		/* The maximum index of this node - implied pivot max */
-	struct maple_alloc *alloc;	/* Allocated nodes for this operation */
+	struct slab_sheaf *sheaf;	/* Allocated nodes for this operation */
+	unsigned long node_request;	/* The number of nodes to allocate for this operation */
 	enum maple_status status;	/* The status of the state (active, start, none, etc) */
 	unsigned char depth;		/* depth of tree descent during write */
 	unsigned char offset;
@@ -490,7 +491,8 @@ struct ma_wr_state {
 		.status = ma_start,					\
 		.min = 0,						\
 		.max = ULONG_MAX,					\
-		.alloc = NULL,						\
+		.node_request = 0,					\
+		.sheaf = NULL,						\
 		.mas_flags = 0,						\
 		.store_type = wr_invalid,				\
 	}