[linux-2.6-block.git] / include / linux / rbtree_augmented.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
  Red Black Trees
  (C) 1999  Andrea Arcangeli <andrea@suse.de>
  (C) 2002  David Woodhouse <dwmw2@infradead.org>
  (C) 2012  Michel Lespinasse <walken@google.com>


  linux/include/linux/rbtree_augmented.h
*/

#ifndef _LINUX_RBTREE_AUGMENTED_H
#define _LINUX_RBTREE_AUGMENTED_H

#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <linux/rcupdate.h>

/*
 * Please note - only struct rb_augment_callbacks and the prototypes for
 * rb_insert_augmented() and rb_erase_augmented() are intended to be public.
 * The rest are implementation details you are not expected to depend on.
 *
 * See Documentation/rbtree.txt for documentation and samples.
 */

struct rb_augment_callbacks {
	void (*propagate)(struct rb_node *node, struct rb_node *stop);
	void (*copy)(struct rb_node *old, struct rb_node *new);
	void (*rotate)(struct rb_node *old, struct rb_node *new);
};

extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));

/*
 * Fixup the rbtree and update the augmented information when rebalancing.
 *
 * On insertion, the user must update the augmented information on the path
 * leading to the inserted node, then call rb_link_node() as usual and
 * rb_insert_augmented() instead of the usual rb_insert_color() call.
 * If rb_insert_augmented() rebalances the rbtree, it will callback into
 * a user provided function to update the augmented information on the
 * affected subtrees.
 */
static inline void
rb_insert_augmented(struct rb_node *node, struct rb_root *root,
		    const struct rb_augment_callbacks *augment)
{
	__rb_insert_augmented(node, root, augment->rotate);
}

static inline void
rb_insert_augmented_cached(struct rb_node *node,
			   struct rb_root_cached *root, bool newleft,
			   const struct rb_augment_callbacks *augment)
{
	if (newleft)
		root->rb_leftmost = node;
	rb_insert_augmented(node, &root->rb_root, augment);
}

/*
 * Template for declaring augmented rbtree callbacks (generic case)
 *
 * RBSTATIC:    'static' or empty
 * RBNAME:      name of the rb_augment_callbacks structure
 * RBSTRUCT:    struct type of the tree nodes
 * RBFIELD:     name of struct rb_node field within RBSTRUCT
 * RBTYPE:      type of the RBAUGMENTED field
 * RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree
 * RBCOMPUTE:   name of function that recomputes the RBAUGMENTED data
 */

#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD,	\
			     RBTYPE, RBAUGMENTED, RBCOMPUTE)		\
static inline void							\
RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop)		\
{									\
	while (rb != stop) {						\
		RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD);	\
		RBTYPE augmented = RBCOMPUTE(node);			\
		if (node->RBAUGMENTED == augmented)			\
			break;						\
		node->RBAUGMENTED = augmented;				\
		rb = rb_parent(&node->RBFIELD);				\
	}								\
}									\
static inline void							\
RBNAME ## _copy(struct rb_node *rb_old, struct rb_node *rb_new)		\
{									\
	RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD);		\
	RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD);		\
	new->RBAUGMENTED = old->RBAUGMENTED;				\
}									\
static void								\
RBNAME ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new)	\
{									\
	RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD);		\
	RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD);		\
	new->RBAUGMENTED = old->RBAUGMENTED;				\
	old->RBAUGMENTED = RBCOMPUTE(old);				\
}									\
RBSTATIC const struct rb_augment_callbacks RBNAME = {			\
	.propagate = RBNAME ## _propagate,				\
	.copy = RBNAME ## _copy,					\
	.rotate = RBNAME ## _rotate					\
};

/*
 * Template for declaring augmented rbtree callbacks,
 * computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes.
 *
 * RBSTATIC:    'static' or empty
 * RBNAME:      name of the rb_augment_callbacks structure
 * RBSTRUCT:    struct type of the tree nodes
 * RBFIELD:     name of struct rb_node field within RBSTRUCT
 * RBTYPE:      type of the RBAUGMENTED field
 * RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree
 * RBCOMPUTE:   name of function that returns the per-node RBTYPE scalar
 */

#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD,	      \
				 RBTYPE, RBAUGMENTED, RBCOMPUTE)	      \
static inline RBTYPE RBNAME ## _compute_max(RBSTRUCT *node)		      \
{									      \
	RBSTRUCT *child;						      \
	RBTYPE max = RBCOMPUTE(node);					      \
	if (node->RBFIELD.rb_left) {					      \
		child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD);   \
		if (child->RBAUGMENTED > max)				      \
			max = child->RBAUGMENTED;			      \
	}								      \
	if (node->RBFIELD.rb_right) {					      \
		child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD);  \
		if (child->RBAUGMENTED > max)				      \
			max = child->RBAUGMENTED;			      \
	}								      \
	return max;							      \
}									      \
RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD,		      \
		     RBTYPE, RBAUGMENTED, RBNAME ## _compute_max)


#define	RB_RED		0
#define	RB_BLACK	1

#define __rb_parent(pc)    ((struct rb_node *)(pc & ~3))

#define __rb_color(pc)     ((pc) & 1)
#define __rb_is_black(pc)  __rb_color(pc)
#define __rb_is_red(pc)    (!__rb_color(pc))
#define rb_color(rb)       __rb_color((rb)->__rb_parent_color)
#define rb_is_red(rb)      __rb_is_red((rb)->__rb_parent_color)
#define rb_is_black(rb)    __rb_is_black((rb)->__rb_parent_color)

static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
{
	rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
}

static inline void rb_set_parent_color(struct rb_node *rb,
				       struct rb_node *p, int color)
{
	rb->__rb_parent_color = (unsigned long)p | color;
}

static inline void
__rb_change_child(struct rb_node *old, struct rb_node *new,
		  struct rb_node *parent, struct rb_root *root)
{
	if (parent) {
		if (parent->rb_left == old)
			WRITE_ONCE(parent->rb_left, new);
		else
			WRITE_ONCE(parent->rb_right, new);
	} else
		WRITE_ONCE(root->rb_node, new);
}

static inline void
__rb_change_child_rcu(struct rb_node *old, struct rb_node *new,
		      struct rb_node *parent, struct rb_root *root)
{
	if (parent) {
		if (parent->rb_left == old)
			rcu_assign_pointer(parent->rb_left, new);
		else
			rcu_assign_pointer(parent->rb_right, new);
	} else
		rcu_assign_pointer(root->rb_node, new);
}

extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));

static __always_inline struct rb_node *
__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
		     const struct rb_augment_callbacks *augment)
{
	struct rb_node *child = node->rb_right;
	struct rb_node *tmp = node->rb_left;
	struct rb_node *parent, *rebalance;
	unsigned long pc;

	if (!tmp) {
		/*
		 * Case 1: node to erase has no more than 1 child (easy!)
		 *
		 * Note that if there is one child it must be red due to 5)
		 * and node must be black due to 4). We adjust colors locally
		 * so as to bypass __rb_erase_color() later on.
		 */
		pc = node->__rb_parent_color;
		parent = __rb_parent(pc);
		__rb_change_child(node, child, parent, root);
		if (child) {
			child->__rb_parent_color = pc;
			rebalance = NULL;
		} else
			rebalance = __rb_is_black(pc) ? parent : NULL;
		tmp = parent;
	} else if (!child) {
		/* Still case 1, but this time the child is node->rb_left */
		tmp->__rb_parent_color = pc = node->__rb_parent_color;
		parent = __rb_parent(pc);
		__rb_change_child(node, tmp, parent, root);
		rebalance = NULL;
		tmp = parent;
	} else {
		struct rb_node *successor = child, *child2;

		tmp = child->rb_left;
		if (!tmp) {
			/*
			 * Case 2: node's successor is its right child
			 *
			 *    (n)          (s)
			 *    / \          / \
			 *  (x) (s)  ->  (x) (c)
			 *        \
			 *        (c)
			 */
			parent = successor;
			child2 = successor->rb_right;

			augment->copy(node, successor);
		} else {
			/*
			 * Case 3: node's successor is leftmost under
			 * node's right child subtree
			 *
			 *    (n)          (s)
			 *    / \          / \
			 *  (x) (y)  ->  (x) (y)
			 *      /            /
			 *    (p)          (p)
			 *    /            /
			 *  (s)          (c)
			 *    \
			 *    (c)
			 */
			do {
				parent = successor;
				successor = tmp;
				tmp = tmp->rb_left;
			} while (tmp);
			child2 = successor->rb_right;
			WRITE_ONCE(parent->rb_left, child2);
			WRITE_ONCE(successor->rb_right, child);
			rb_set_parent(child, successor);

			augment->copy(node, successor);
			augment->propagate(parent, successor);
		}

		tmp = node->rb_left;
		WRITE_ONCE(successor->rb_left, tmp);
		rb_set_parent(tmp, successor);

		pc = node->__rb_parent_color;
		tmp = __rb_parent(pc);
		__rb_change_child(node, successor, tmp, root);

		if (child2) {
			successor->__rb_parent_color = pc;
			rb_set_parent_color(child2, parent, RB_BLACK);
			rebalance = NULL;
		} else {
			unsigned long pc2 = successor->__rb_parent_color;
			successor->__rb_parent_color = pc;
			rebalance = __rb_is_black(pc2) ? parent : NULL;
		}
		tmp = successor;
	}

	augment->propagate(tmp, NULL);
	return rebalance;
}

static __always_inline void
rb_erase_augmented(struct rb_node *node, struct rb_root *root,
		   const struct rb_augment_callbacks *augment)
{
	struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
	if (rebalance)
		__rb_erase_color(rebalance, root, augment->rotate);
}

static __always_inline void
rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,
			  const struct rb_augment_callbacks *augment)
{
	if (root->rb_leftmost == node)
		root->rb_leftmost = rb_next(node);
	rb_erase_augmented(node, &root->rb_root, augment);
}

#endif	/* _LINUX_RBTREE_AUGMENTED_H */
Commit	Line	Data
1a59d1b8	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
9c079add ML	2	/*
	3	Red Black Trees
	4	(C) 1999 Andrea Arcangeli <andrea@suse.de>
	5	(C) 2002 David Woodhouse <dwmw2@infradead.org>
	6	(C) 2012 Michel Lespinasse <walken@google.com>
	7
9c079add ML	8
	9	linux/include/linux/rbtree_augmented.h
	10	*/
	11
	12	#ifndef _LINUX_RBTREE_AUGMENTED_H
	13	#define _LINUX_RBTREE_AUGMENTED_H
	14
29fc7c5a	15	#include <linux/compiler.h>
9c079add	16	#include <linux/rbtree.h>
2075b16e	17	#include <linux/rcupdate.h>
9c079add ML	18
	19	/*
	20	* Please note - only struct rb_augment_callbacks and the prototypes for
	21	* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
	22	* The rest are implementation details you are not expected to depend on.
	23	*
	24	* See Documentation/rbtree.txt for documentation and samples.
	25	*/
	26
	27	struct rb_augment_callbacks {
	28	void (propagate)(struct rb_node node, struct rb_node *stop);
	29	void (copy)(struct rb_node old, struct rb_node *new);
	30	void (rotate)(struct rb_node old, struct rb_node *new);
	31	};
	32
9f973cb3	33	extern void __rb_insert_augmented(struct rb_node node, struct rb_root root,
9c079add	34	void (augment_rotate)(struct rb_node old, struct rb_node *new));
9f973cb3	35
a841b659 LJ	36	/*
	37	* Fixup the rbtree and update the augmented information when rebalancing.
	38	*
	39	* On insertion, the user must update the augmented information on the path
	40	* leading to the inserted node, then call rb_link_node() as usual and
7e5ca363 WY	41	* rb_insert_augmented() instead of the usual rb_insert_color() call.
7e5ca363 WY	42	* If rb_insert_augmented() rebalances the rbtree, it will callback into
a841b659 LJ	43	* a user provided function to update the augmented information on the
	44	* affected subtrees.
	45	*/
9c079add ML	46	static inline void
	47	rb_insert_augmented(struct rb_node node, struct rb_root root,
	48	const struct rb_augment_callbacks *augment)
	49	{
9f973cb3	50	__rb_insert_augmented(node, root, augment->rotate);
cd9e61ed DB	51	}
	52
	53	static inline void
	54	rb_insert_augmented_cached(struct rb_node *node,
	55	struct rb_root_cached *root, bool newleft,
	56	const struct rb_augment_callbacks *augment)
	57	{
9f973cb3 ML	58	if (newleft)
	59	root->rb_leftmost = node;
	60	rb_insert_augmented(node, &root->rb_root, augment);
9c079add ML	61	}
9c079add ML	62
444b8a83	63	/*
315cc066	64	* Template for declaring augmented rbtree callbacks (generic case)
444b8a83 ML	65	*
	66	* RBSTATIC: 'static' or empty
	67	* RBNAME: name of the rb_augment_callbacks structure
	68	* RBSTRUCT: struct type of the tree nodes
	69	* RBFIELD: name of struct rb_node field within RBSTRUCT
	70	* RBTYPE: type of the RBAUGMENTED field
	71	* RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree
	72	* RBCOMPUTE: name of function that recomputes the RBAUGMENTED data
	73	*/
	74
	75	#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
	76	RBTYPE, RBAUGMENTED, RBCOMPUTE) \
9c079add	77	static inline void \
444b8a83	78	RBNAME ## _propagate(struct rb_node rb, struct rb_node stop) \
9c079add ML	79	{ \
9c079add ML	80	while (rb != stop) { \
444b8a83 ML	81	RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \
	82	RBTYPE augmented = RBCOMPUTE(node); \
	83	if (node->RBAUGMENTED == augmented) \
9c079add	84	break; \
444b8a83 ML	85	node->RBAUGMENTED = augmented; \
444b8a83 ML	86	rb = rb_parent(&node->RBFIELD); \
9c079add ML	87	} \
	88	} \
	89	static inline void \
444b8a83	90	RBNAME ## _copy(struct rb_node rb_old, struct rb_node rb_new) \
9c079add	91	{ \
444b8a83 ML	92	RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \
	93	RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \
	94	new->RBAUGMENTED = old->RBAUGMENTED; \
9c079add ML	95	} \
9c079add ML	96	static void \
444b8a83	97	RBNAME ## _rotate(struct rb_node rb_old, struct rb_node rb_new) \
9c079add	98	{ \
444b8a83 ML	99	RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \
	100	RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \
	101	new->RBAUGMENTED = old->RBAUGMENTED; \
	102	old->RBAUGMENTED = RBCOMPUTE(old); \
9c079add	103	} \
444b8a83 ML	104	RBSTATIC const struct rb_augment_callbacks RBNAME = { \
	105	.propagate = RBNAME ## _propagate, \
	106	.copy = RBNAME ## _copy, \
	107	.rotate = RBNAME ## _rotate \
9c079add ML	108	};
9c079add ML	109
315cc066 ML	110	/*
	111	* Template for declaring augmented rbtree callbacks,
	112	* computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes.
	113	*
	114	* RBSTATIC: 'static' or empty
	115	* RBNAME: name of the rb_augment_callbacks structure
	116	* RBSTRUCT: struct type of the tree nodes
	117	* RBFIELD: name of struct rb_node field within RBSTRUCT
	118	* RBTYPE: type of the RBAUGMENTED field
	119	* RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree
	120	* RBCOMPUTE: name of function that returns the per-node RBTYPE scalar
	121	*/
	122
	123	#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
	124	RBTYPE, RBAUGMENTED, RBCOMPUTE) \
	125	static inline RBTYPE RBNAME ## _compute_max(RBSTRUCT *node) \
	126	{ \
	127	RBSTRUCT *child; \
	128	RBTYPE max = RBCOMPUTE(node); \
	129	if (node->RBFIELD.rb_left) { \
	130	child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \
	131	if (child->RBAUGMENTED > max) \
	132	max = child->RBAUGMENTED; \
	133	} \
	134	if (node->RBFIELD.rb_right) { \
	135	child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \
	136	if (child->RBAUGMENTED > max) \
	137	max = child->RBAUGMENTED; \
	138	} \
	139	return max; \
	140	} \
	141	RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
	142	RBTYPE, RBAUGMENTED, RBNAME ## _compute_max)
	143
9c079add ML	144
	145	#define RB_RED 0
	146	#define RB_BLACK 1
	147
	148	#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
	149
	150	#define __rb_color(pc) ((pc) & 1)
	151	#define __rb_is_black(pc) __rb_color(pc)
	152	#define __rb_is_red(pc) (!__rb_color(pc))
	153	#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
	154	#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
	155	#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
	156
	157	static inline void rb_set_parent(struct rb_node rb, struct rb_node p)
	158	{
	159	rb->__rb_parent_color = rb_color(rb) \| (unsigned long)p;
	160	}
	161
	162	static inline void rb_set_parent_color(struct rb_node *rb,
	163	struct rb_node *p, int color)
	164	{
	165	rb->__rb_parent_color = (unsigned long)p \| color;
	166	}
	167
	168	static inline void
	169	__rb_change_child(struct rb_node old, struct rb_node new,
	170	struct rb_node parent, struct rb_root root)
	171	{
	172	if (parent) {
	173	if (parent->rb_left == old)
d72da4a4	174	WRITE_ONCE(parent->rb_left, new);
9c079add	175	else
d72da4a4	176	WRITE_ONCE(parent->rb_right, new);
9c079add	177	} else
d72da4a4	178	WRITE_ONCE(root->rb_node, new);
9c079add ML	179	}
9c079add ML	180
c1adf200 DH	181	static inline void
	182	__rb_change_child_rcu(struct rb_node old, struct rb_node new,
	183	struct rb_node parent, struct rb_root root)
	184	{
	185	if (parent) {
	186	if (parent->rb_left == old)
	187	rcu_assign_pointer(parent->rb_left, new);
	188	else
	189	rcu_assign_pointer(parent->rb_right, new);
	190	} else
	191	rcu_assign_pointer(root->rb_node, new);
	192	}
	193
9c079add ML	194	extern void __rb_erase_color(struct rb_node parent, struct rb_root root,
	195	void (augment_rotate)(struct rb_node old, struct rb_node *new));
	196
3cb7a563 ML	197	static __always_inline struct rb_node *
	198	__rb_erase_augmented(struct rb_node node, struct rb_root root,
	199	const struct rb_augment_callbacks *augment)
9c079add	200	{
d72da4a4 PZ	201	struct rb_node *child = node->rb_right;
d72da4a4 PZ	202	struct rb_node *tmp = node->rb_left;
9c079add ML	203	struct rb_node parent, rebalance;
	204	unsigned long pc;
	205
	206	if (!tmp) {
	207	/*
	208	* Case 1: node to erase has no more than 1 child (easy!)
	209	*
	210	* Note that if there is one child it must be red due to 5)
	211	* and node must be black due to 4). We adjust colors locally
	212	* so as to bypass __rb_erase_color() later on.
	213	*/
	214	pc = node->__rb_parent_color;
	215	parent = __rb_parent(pc);
	216	__rb_change_child(node, child, parent, root);
	217	if (child) {
	218	child->__rb_parent_color = pc;
	219	rebalance = NULL;
	220	} else
	221	rebalance = __rb_is_black(pc) ? parent : NULL;
	222	tmp = parent;
	223	} else if (!child) {
	224	/* Still case 1, but this time the child is node->rb_left */
	225	tmp->__rb_parent_color = pc = node->__rb_parent_color;
	226	parent = __rb_parent(pc);
	227	__rb_change_child(node, tmp, parent, root);
	228	rebalance = NULL;
	229	tmp = parent;
	230	} else {
	231	struct rb_node successor = child, child2;
d72da4a4	232
9c079add ML	233	tmp = child->rb_left;
	234	if (!tmp) {
	235	/*
	236	* Case 2: node's successor is its right child
	237	*
	238	* (n) (s)
	239	* / \ / \
	240	* (x) (s) -> (x) (c)
	241	* \
	242	* (c)
	243	*/
	244	parent = successor;
	245	child2 = successor->rb_right;
d72da4a4	246
9c079add ML	247	augment->copy(node, successor);
	248	} else {
	249	/*
	250	* Case 3: node's successor is leftmost under
	251	* node's right child subtree
	252	*
	253	* (n) (s)
	254	* / \ / \
	255	* (x) (y) -> (x) (y)
	256	* / /
	257	* (p) (p)
	258	* / /
	259	* (s) (c)
	260	* \
	261	* (c)
	262	*/
	263	do {
	264	parent = successor;
	265	successor = tmp;
	266	tmp = tmp->rb_left;
	267	} while (tmp);
d72da4a4 PZ	268	child2 = successor->rb_right;
	269	WRITE_ONCE(parent->rb_left, child2);
	270	WRITE_ONCE(successor->rb_right, child);
9c079add	271	rb_set_parent(child, successor);
d72da4a4	272
9c079add ML	273	augment->copy(node, successor);
	274	augment->propagate(parent, successor);
	275	}
	276
d72da4a4 PZ	277	tmp = node->rb_left;
d72da4a4 PZ	278	WRITE_ONCE(successor->rb_left, tmp);
9c079add ML	279	rb_set_parent(tmp, successor);
	280
	281	pc = node->__rb_parent_color;
	282	tmp = __rb_parent(pc);
	283	__rb_change_child(node, successor, tmp, root);
d72da4a4	284
9c079add ML	285	if (child2) {
	286	successor->__rb_parent_color = pc;
	287	rb_set_parent_color(child2, parent, RB_BLACK);
	288	rebalance = NULL;
	289	} else {
	290	unsigned long pc2 = successor->__rb_parent_color;
	291	successor->__rb_parent_color = pc;
	292	rebalance = __rb_is_black(pc2) ? parent : NULL;
	293	}
	294	tmp = successor;
	295	}
	296
	297	augment->propagate(tmp, NULL);
3cb7a563 ML	298	return rebalance;
	299	}
	300
	301	static __always_inline void
	302	rb_erase_augmented(struct rb_node node, struct rb_root root,
	303	const struct rb_augment_callbacks *augment)
	304	{
9f973cb3	305	struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
9c079add ML	306	if (rebalance)
	307	__rb_erase_color(rebalance, root, augment->rotate);
	308	}
	309
cd9e61ed DB	310	static __always_inline void
	311	rb_erase_augmented_cached(struct rb_node node, struct rb_root_cached root,
	312	const struct rb_augment_callbacks *augment)
	313	{
9f973cb3 ML	314	if (root->rb_leftmost == node)
	315	root->rb_leftmost = rb_next(node);
	316	rb_erase_augmented(node, &root->rb_root, augment);
cd9e61ed DB	317	}
cd9e61ed DB	318
9c079add	319	#endif /* _LINUX_RBTREE_AUGMENTED_H */