11a59d1b8SThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-or-later */
29c079addSMichel Lespinasse /*
39c079addSMichel Lespinasse Red Black Trees
49c079addSMichel Lespinasse (C) 1999 Andrea Arcangeli <andrea@suse.de>
59c079addSMichel Lespinasse (C) 2002 David Woodhouse <dwmw2@infradead.org>
69c079addSMichel Lespinasse (C) 2012 Michel Lespinasse <walken@google.com>
79c079addSMichel Lespinasse
89c079addSMichel Lespinasse
99c079addSMichel Lespinasse linux/include/linux/rbtree_augmented.h
109c079addSMichel Lespinasse */
119c079addSMichel Lespinasse
129c079addSMichel Lespinasse #ifndef _LINUX_RBTREE_AUGMENTED_H
139c079addSMichel Lespinasse #define _LINUX_RBTREE_AUGMENTED_H
149c079addSMichel Lespinasse
1529fc7c5aSWill Deacon #include <linux/compiler.h>
169c079addSMichel Lespinasse #include <linux/rbtree.h>
172075b16eSSebastian Andrzej Siewior #include <linux/rcupdate.h>
189c079addSMichel Lespinasse
199c079addSMichel Lespinasse /*
209c079addSMichel Lespinasse * Please note - only struct rb_augment_callbacks and the prototypes for
219c079addSMichel Lespinasse * rb_insert_augmented() and rb_erase_augmented() are intended to be public.
229c079addSMichel Lespinasse * The rest are implementation details you are not expected to depend on.
239c079addSMichel Lespinasse *
2414bbe3e3SMatthew Wilcox (Oracle) * See Documentation/core-api/rbtree.rst for documentation and samples.
259c079addSMichel Lespinasse */
269c079addSMichel Lespinasse
279c079addSMichel Lespinasse struct rb_augment_callbacks {
289c079addSMichel Lespinasse void (*propagate)(struct rb_node *node, struct rb_node *stop);
299c079addSMichel Lespinasse void (*copy)(struct rb_node *old, struct rb_node *new);
309c079addSMichel Lespinasse void (*rotate)(struct rb_node *old, struct rb_node *new);
319c079addSMichel Lespinasse };
329c079addSMichel Lespinasse
339f973cb3SMichel Lespinasse extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
349c079addSMichel Lespinasse void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
359f973cb3SMichel Lespinasse
36a841b659SLai Jiangshan /*
37a841b659SLai Jiangshan * Fixup the rbtree and update the augmented information when rebalancing.
38a841b659SLai Jiangshan *
39a841b659SLai Jiangshan * On insertion, the user must update the augmented information on the path
40a841b659SLai Jiangshan * leading to the inserted node, then call rb_link_node() as usual and
417e5ca363SWei Yang * rb_insert_augmented() instead of the usual rb_insert_color() call.
427e5ca363SWei Yang * If rb_insert_augmented() rebalances the rbtree, it will callback into
43a841b659SLai Jiangshan * a user provided function to update the augmented information on the
44a841b659SLai Jiangshan * affected subtrees.
45a841b659SLai Jiangshan */
469c079addSMichel Lespinasse static inline void
rb_insert_augmented(struct rb_node * node,struct rb_root * root,const struct rb_augment_callbacks * augment)479c079addSMichel Lespinasse rb_insert_augmented(struct rb_node *node, struct rb_root *root,
489c079addSMichel Lespinasse const struct rb_augment_callbacks *augment)
499c079addSMichel Lespinasse {
509f973cb3SMichel Lespinasse __rb_insert_augmented(node, root, augment->rotate);
51cd9e61edSDavidlohr Bueso }
52cd9e61edSDavidlohr Bueso
53cd9e61edSDavidlohr Bueso static inline void
rb_insert_augmented_cached(struct rb_node * node,struct rb_root_cached * root,bool newleft,const struct rb_augment_callbacks * augment)54cd9e61edSDavidlohr Bueso rb_insert_augmented_cached(struct rb_node *node,
55cd9e61edSDavidlohr Bueso struct rb_root_cached *root, bool newleft,
56cd9e61edSDavidlohr Bueso const struct rb_augment_callbacks *augment)
57cd9e61edSDavidlohr Bueso {
589f973cb3SMichel Lespinasse if (newleft)
599f973cb3SMichel Lespinasse root->rb_leftmost = node;
609f973cb3SMichel Lespinasse rb_insert_augmented(node, &root->rb_root, augment);
619c079addSMichel Lespinasse }
629c079addSMichel Lespinasse
63*99d4d265SPeter Zijlstra static __always_inline struct rb_node *
rb_add_augmented_cached(struct rb_node * node,struct rb_root_cached * tree,bool (* less)(struct rb_node *,const struct rb_node *),const struct rb_augment_callbacks * augment)64*99d4d265SPeter Zijlstra rb_add_augmented_cached(struct rb_node *node, struct rb_root_cached *tree,
65*99d4d265SPeter Zijlstra bool (*less)(struct rb_node *, const struct rb_node *),
66*99d4d265SPeter Zijlstra const struct rb_augment_callbacks *augment)
67*99d4d265SPeter Zijlstra {
68*99d4d265SPeter Zijlstra struct rb_node **link = &tree->rb_root.rb_node;
69*99d4d265SPeter Zijlstra struct rb_node *parent = NULL;
70*99d4d265SPeter Zijlstra bool leftmost = true;
71*99d4d265SPeter Zijlstra
72*99d4d265SPeter Zijlstra while (*link) {
73*99d4d265SPeter Zijlstra parent = *link;
74*99d4d265SPeter Zijlstra if (less(node, parent)) {
75*99d4d265SPeter Zijlstra link = &parent->rb_left;
76*99d4d265SPeter Zijlstra } else {
77*99d4d265SPeter Zijlstra link = &parent->rb_right;
78*99d4d265SPeter Zijlstra leftmost = false;
79*99d4d265SPeter Zijlstra }
80*99d4d265SPeter Zijlstra }
81*99d4d265SPeter Zijlstra
82*99d4d265SPeter Zijlstra rb_link_node(node, parent, link);
83*99d4d265SPeter Zijlstra augment->propagate(parent, NULL); /* suboptimal */
84*99d4d265SPeter Zijlstra rb_insert_augmented_cached(node, tree, leftmost, augment);
85*99d4d265SPeter Zijlstra
86*99d4d265SPeter Zijlstra return leftmost ? node : NULL;
87*99d4d265SPeter Zijlstra }
88*99d4d265SPeter Zijlstra
89444b8a83SMichel Lespinasse /*
90315cc066SMichel Lespinasse * Template for declaring augmented rbtree callbacks (generic case)
91444b8a83SMichel Lespinasse *
92444b8a83SMichel Lespinasse * RBSTATIC: 'static' or empty
93444b8a83SMichel Lespinasse * RBNAME: name of the rb_augment_callbacks structure
94444b8a83SMichel Lespinasse * RBSTRUCT: struct type of the tree nodes
95444b8a83SMichel Lespinasse * RBFIELD: name of struct rb_node field within RBSTRUCT
966d2052d1SMichel Lespinasse * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree
97444b8a83SMichel Lespinasse * RBCOMPUTE: name of function that recomputes the RBAUGMENTED data
98444b8a83SMichel Lespinasse */
99444b8a83SMichel Lespinasse
1006d2052d1SMichel Lespinasse #define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
1016d2052d1SMichel Lespinasse RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \
1029c079addSMichel Lespinasse static inline void \
103444b8a83SMichel Lespinasse RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop) \
1049c079addSMichel Lespinasse { \
1059c079addSMichel Lespinasse while (rb != stop) { \
106444b8a83SMichel Lespinasse RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \
1076d2052d1SMichel Lespinasse if (RBCOMPUTE(node, true)) \
1089c079addSMichel Lespinasse break; \
109444b8a83SMichel Lespinasse rb = rb_parent(&node->RBFIELD); \
1109c079addSMichel Lespinasse } \
1119c079addSMichel Lespinasse } \
1129c079addSMichel Lespinasse static inline void \
113444b8a83SMichel Lespinasse RBNAME ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
1149c079addSMichel Lespinasse { \
115444b8a83SMichel Lespinasse RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \
116444b8a83SMichel Lespinasse RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \
117444b8a83SMichel Lespinasse new->RBAUGMENTED = old->RBAUGMENTED; \
1189c079addSMichel Lespinasse } \
1199c079addSMichel Lespinasse static void \
120444b8a83SMichel Lespinasse RBNAME ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
1219c079addSMichel Lespinasse { \
122444b8a83SMichel Lespinasse RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \
123444b8a83SMichel Lespinasse RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \
124444b8a83SMichel Lespinasse new->RBAUGMENTED = old->RBAUGMENTED; \
1256d2052d1SMichel Lespinasse RBCOMPUTE(old, false); \
1269c079addSMichel Lespinasse } \
127444b8a83SMichel Lespinasse RBSTATIC const struct rb_augment_callbacks RBNAME = { \
128444b8a83SMichel Lespinasse .propagate = RBNAME ## _propagate, \
129444b8a83SMichel Lespinasse .copy = RBNAME ## _copy, \
130444b8a83SMichel Lespinasse .rotate = RBNAME ## _rotate \
1319c079addSMichel Lespinasse };
1329c079addSMichel Lespinasse
133315cc066SMichel Lespinasse /*
134315cc066SMichel Lespinasse * Template for declaring augmented rbtree callbacks,
135315cc066SMichel Lespinasse * computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes.
136315cc066SMichel Lespinasse *
137315cc066SMichel Lespinasse * RBSTATIC: 'static' or empty
138315cc066SMichel Lespinasse * RBNAME: name of the rb_augment_callbacks structure
139315cc066SMichel Lespinasse * RBSTRUCT: struct type of the tree nodes
140315cc066SMichel Lespinasse * RBFIELD: name of struct rb_node field within RBSTRUCT
141315cc066SMichel Lespinasse * RBTYPE: type of the RBAUGMENTED field
142315cc066SMichel Lespinasse * RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree
143315cc066SMichel Lespinasse * RBCOMPUTE: name of function that returns the per-node RBTYPE scalar
144315cc066SMichel Lespinasse */
145315cc066SMichel Lespinasse
146315cc066SMichel Lespinasse #define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
147315cc066SMichel Lespinasse RBTYPE, RBAUGMENTED, RBCOMPUTE) \
1486d2052d1SMichel Lespinasse static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \
149315cc066SMichel Lespinasse { \
150315cc066SMichel Lespinasse RBSTRUCT *child; \
151315cc066SMichel Lespinasse RBTYPE max = RBCOMPUTE(node); \
152315cc066SMichel Lespinasse if (node->RBFIELD.rb_left) { \
153315cc066SMichel Lespinasse child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \
154315cc066SMichel Lespinasse if (child->RBAUGMENTED > max) \
155315cc066SMichel Lespinasse max = child->RBAUGMENTED; \
156315cc066SMichel Lespinasse } \
157315cc066SMichel Lespinasse if (node->RBFIELD.rb_right) { \
158315cc066SMichel Lespinasse child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \
159315cc066SMichel Lespinasse if (child->RBAUGMENTED > max) \
160315cc066SMichel Lespinasse max = child->RBAUGMENTED; \
161315cc066SMichel Lespinasse } \
1626d2052d1SMichel Lespinasse if (exit && node->RBAUGMENTED == max) \
1636d2052d1SMichel Lespinasse return true; \
1646d2052d1SMichel Lespinasse node->RBAUGMENTED = max; \
1656d2052d1SMichel Lespinasse return false; \
166315cc066SMichel Lespinasse } \
1676d2052d1SMichel Lespinasse RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
1686d2052d1SMichel Lespinasse RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max)
169315cc066SMichel Lespinasse
1709c079addSMichel Lespinasse
1719c079addSMichel Lespinasse #define RB_RED 0
1729c079addSMichel Lespinasse #define RB_BLACK 1
1739c079addSMichel Lespinasse
1749c079addSMichel Lespinasse #define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
1759c079addSMichel Lespinasse
1769c079addSMichel Lespinasse #define __rb_color(pc) ((pc) & 1)
1779c079addSMichel Lespinasse #define __rb_is_black(pc) __rb_color(pc)
1789c079addSMichel Lespinasse #define __rb_is_red(pc) (!__rb_color(pc))
1799c079addSMichel Lespinasse #define rb_color(rb) __rb_color((rb)->__rb_parent_color)
1809c079addSMichel Lespinasse #define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
1819c079addSMichel Lespinasse #define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
1829c079addSMichel Lespinasse
rb_set_parent(struct rb_node * rb,struct rb_node * p)1839c079addSMichel Lespinasse static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
1849c079addSMichel Lespinasse {
185b0687c11SNoah Goldstein rb->__rb_parent_color = rb_color(rb) + (unsigned long)p;
1869c079addSMichel Lespinasse }
1879c079addSMichel Lespinasse
rb_set_parent_color(struct rb_node * rb,struct rb_node * p,int color)1889c079addSMichel Lespinasse static inline void rb_set_parent_color(struct rb_node *rb,
1899c079addSMichel Lespinasse struct rb_node *p, int color)
1909c079addSMichel Lespinasse {
191b0687c11SNoah Goldstein rb->__rb_parent_color = (unsigned long)p + color;
1929c079addSMichel Lespinasse }
1939c079addSMichel Lespinasse
1949c079addSMichel Lespinasse static inline void
__rb_change_child(struct rb_node * old,struct rb_node * new,struct rb_node * parent,struct rb_root * root)1959c079addSMichel Lespinasse __rb_change_child(struct rb_node *old, struct rb_node *new,
1969c079addSMichel Lespinasse struct rb_node *parent, struct rb_root *root)
1979c079addSMichel Lespinasse {
1989c079addSMichel Lespinasse if (parent) {
1999c079addSMichel Lespinasse if (parent->rb_left == old)
200d72da4a4SPeter Zijlstra WRITE_ONCE(parent->rb_left, new);
2019c079addSMichel Lespinasse else
202d72da4a4SPeter Zijlstra WRITE_ONCE(parent->rb_right, new);
2039c079addSMichel Lespinasse } else
204d72da4a4SPeter Zijlstra WRITE_ONCE(root->rb_node, new);
2059c079addSMichel Lespinasse }
2069c079addSMichel Lespinasse
207c1adf200SDavid Howells static inline void
__rb_change_child_rcu(struct rb_node * old,struct rb_node * new,struct rb_node * parent,struct rb_root * root)208c1adf200SDavid Howells __rb_change_child_rcu(struct rb_node *old, struct rb_node *new,
209c1adf200SDavid Howells struct rb_node *parent, struct rb_root *root)
210c1adf200SDavid Howells {
211c1adf200SDavid Howells if (parent) {
212c1adf200SDavid Howells if (parent->rb_left == old)
213c1adf200SDavid Howells rcu_assign_pointer(parent->rb_left, new);
214c1adf200SDavid Howells else
215c1adf200SDavid Howells rcu_assign_pointer(parent->rb_right, new);
216c1adf200SDavid Howells } else
217c1adf200SDavid Howells rcu_assign_pointer(root->rb_node, new);
218c1adf200SDavid Howells }
219c1adf200SDavid Howells
2209c079addSMichel Lespinasse extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
2219c079addSMichel Lespinasse void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
2229c079addSMichel Lespinasse
2233cb7a563SMichel Lespinasse static __always_inline struct rb_node *
__rb_erase_augmented(struct rb_node * node,struct rb_root * root,const struct rb_augment_callbacks * augment)2243cb7a563SMichel Lespinasse __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
2259c079addSMichel Lespinasse const struct rb_augment_callbacks *augment)
2269c079addSMichel Lespinasse {
227d72da4a4SPeter Zijlstra struct rb_node *child = node->rb_right;
228d72da4a4SPeter Zijlstra struct rb_node *tmp = node->rb_left;
2299c079addSMichel Lespinasse struct rb_node *parent, *rebalance;
2309c079addSMichel Lespinasse unsigned long pc;
2319c079addSMichel Lespinasse
2329c079addSMichel Lespinasse if (!tmp) {
2339c079addSMichel Lespinasse /*
2349c079addSMichel Lespinasse * Case 1: node to erase has no more than 1 child (easy!)
2359c079addSMichel Lespinasse *
2369c079addSMichel Lespinasse * Note that if there is one child it must be red due to 5)
2379c079addSMichel Lespinasse * and node must be black due to 4). We adjust colors locally
2389c079addSMichel Lespinasse * so as to bypass __rb_erase_color() later on.
2399c079addSMichel Lespinasse */
2409c079addSMichel Lespinasse pc = node->__rb_parent_color;
2419c079addSMichel Lespinasse parent = __rb_parent(pc);
2429c079addSMichel Lespinasse __rb_change_child(node, child, parent, root);
2439c079addSMichel Lespinasse if (child) {
2449c079addSMichel Lespinasse child->__rb_parent_color = pc;
2459c079addSMichel Lespinasse rebalance = NULL;
2469c079addSMichel Lespinasse } else
2479c079addSMichel Lespinasse rebalance = __rb_is_black(pc) ? parent : NULL;
2489c079addSMichel Lespinasse tmp = parent;
2499c079addSMichel Lespinasse } else if (!child) {
2509c079addSMichel Lespinasse /* Still case 1, but this time the child is node->rb_left */
2519c079addSMichel Lespinasse tmp->__rb_parent_color = pc = node->__rb_parent_color;
2529c079addSMichel Lespinasse parent = __rb_parent(pc);
2539c079addSMichel Lespinasse __rb_change_child(node, tmp, parent, root);
2549c079addSMichel Lespinasse rebalance = NULL;
2559c079addSMichel Lespinasse tmp = parent;
2569c079addSMichel Lespinasse } else {
2579c079addSMichel Lespinasse struct rb_node *successor = child, *child2;
258d72da4a4SPeter Zijlstra
2599c079addSMichel Lespinasse tmp = child->rb_left;
2609c079addSMichel Lespinasse if (!tmp) {
2619c079addSMichel Lespinasse /*
2629c079addSMichel Lespinasse * Case 2: node's successor is its right child
2639c079addSMichel Lespinasse *
2649c079addSMichel Lespinasse * (n) (s)
2659c079addSMichel Lespinasse * / \ / \
2669c079addSMichel Lespinasse * (x) (s) -> (x) (c)
2679c079addSMichel Lespinasse * \
2689c079addSMichel Lespinasse * (c)
2699c079addSMichel Lespinasse */
2709c079addSMichel Lespinasse parent = successor;
2719c079addSMichel Lespinasse child2 = successor->rb_right;
272d72da4a4SPeter Zijlstra
2739c079addSMichel Lespinasse augment->copy(node, successor);
2749c079addSMichel Lespinasse } else {
2759c079addSMichel Lespinasse /*
2769c079addSMichel Lespinasse * Case 3: node's successor is leftmost under
2779c079addSMichel Lespinasse * node's right child subtree
2789c079addSMichel Lespinasse *
2799c079addSMichel Lespinasse * (n) (s)
2809c079addSMichel Lespinasse * / \ / \
2819c079addSMichel Lespinasse * (x) (y) -> (x) (y)
2829c079addSMichel Lespinasse * / /
2839c079addSMichel Lespinasse * (p) (p)
2849c079addSMichel Lespinasse * / /
2859c079addSMichel Lespinasse * (s) (c)
2869c079addSMichel Lespinasse * \
2879c079addSMichel Lespinasse * (c)
2889c079addSMichel Lespinasse */
2899c079addSMichel Lespinasse do {
2909c079addSMichel Lespinasse parent = successor;
2919c079addSMichel Lespinasse successor = tmp;
2929c079addSMichel Lespinasse tmp = tmp->rb_left;
2939c079addSMichel Lespinasse } while (tmp);
294d72da4a4SPeter Zijlstra child2 = successor->rb_right;
295d72da4a4SPeter Zijlstra WRITE_ONCE(parent->rb_left, child2);
296d72da4a4SPeter Zijlstra WRITE_ONCE(successor->rb_right, child);
2979c079addSMichel Lespinasse rb_set_parent(child, successor);
298d72da4a4SPeter Zijlstra
2999c079addSMichel Lespinasse augment->copy(node, successor);
3009c079addSMichel Lespinasse augment->propagate(parent, successor);
3019c079addSMichel Lespinasse }
3029c079addSMichel Lespinasse
303d72da4a4SPeter Zijlstra tmp = node->rb_left;
304d72da4a4SPeter Zijlstra WRITE_ONCE(successor->rb_left, tmp);
3059c079addSMichel Lespinasse rb_set_parent(tmp, successor);
3069c079addSMichel Lespinasse
3079c079addSMichel Lespinasse pc = node->__rb_parent_color;
3089c079addSMichel Lespinasse tmp = __rb_parent(pc);
3099c079addSMichel Lespinasse __rb_change_child(node, successor, tmp, root);
310d72da4a4SPeter Zijlstra
3119c079addSMichel Lespinasse if (child2) {
3129c079addSMichel Lespinasse rb_set_parent_color(child2, parent, RB_BLACK);
3139c079addSMichel Lespinasse rebalance = NULL;
3149c079addSMichel Lespinasse } else {
3158b7569a2SWei Yang rebalance = rb_is_black(successor) ? parent : NULL;
3169c079addSMichel Lespinasse }
31711d43e62SWei Yang successor->__rb_parent_color = pc;
3189c079addSMichel Lespinasse tmp = successor;
3199c079addSMichel Lespinasse }
3209c079addSMichel Lespinasse
3219c079addSMichel Lespinasse augment->propagate(tmp, NULL);
3223cb7a563SMichel Lespinasse return rebalance;
3233cb7a563SMichel Lespinasse }
3243cb7a563SMichel Lespinasse
3253cb7a563SMichel Lespinasse static __always_inline void
rb_erase_augmented(struct rb_node * node,struct rb_root * root,const struct rb_augment_callbacks * augment)3263cb7a563SMichel Lespinasse rb_erase_augmented(struct rb_node *node, struct rb_root *root,
3273cb7a563SMichel Lespinasse const struct rb_augment_callbacks *augment)
3283cb7a563SMichel Lespinasse {
3299f973cb3SMichel Lespinasse struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
3309c079addSMichel Lespinasse if (rebalance)
3319c079addSMichel Lespinasse __rb_erase_color(rebalance, root, augment->rotate);
3329c079addSMichel Lespinasse }
3339c079addSMichel Lespinasse
334cd9e61edSDavidlohr Bueso static __always_inline void
rb_erase_augmented_cached(struct rb_node * node,struct rb_root_cached * root,const struct rb_augment_callbacks * augment)335cd9e61edSDavidlohr Bueso rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,
336cd9e61edSDavidlohr Bueso const struct rb_augment_callbacks *augment)
337cd9e61edSDavidlohr Bueso {
3389f973cb3SMichel Lespinasse if (root->rb_leftmost == node)
3399f973cb3SMichel Lespinasse root->rb_leftmost = rb_next(node);
3409f973cb3SMichel Lespinasse rb_erase_augmented(node, &root->rb_root, augment);
341cd9e61edSDavidlohr Bueso }
342cd9e61edSDavidlohr Bueso
3439c079addSMichel Lespinasse #endif /* _LINUX_RBTREE_AUGMENTED_H */
344