1 /*
2 * mm/interval_tree.c - interval tree for mapping->i_mmap
3 *
4 * Copyright (C) 2012, Michel Lespinasse <walken@google.com>
5 *
6 * This file is released under the GPL v2.
7 */
8
9 #include <linux/mm.h>
10 #include <linux/fs.h>
11 #include <linux/rmap.h>
12 #include <linux/interval_tree_generic.h>
13
vma_start_pgoff(struct vm_area_struct * v)14 static inline unsigned long vma_start_pgoff(struct vm_area_struct *v)
15 {
16 return v->vm_pgoff;
17 }
18
vma_last_pgoff(struct vm_area_struct * v)19 static inline unsigned long vma_last_pgoff(struct vm_area_struct *v)
20 {
21 return v->vm_pgoff + ((v->vm_end - v->vm_start) >> PAGE_SHIFT) - 1;
22 }
23
24 INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb,
25 unsigned long, shared.rb_subtree_last,
26 vma_start_pgoff, vma_last_pgoff,, vma_interval_tree)
27
28 /* Insert node immediately after prev in the interval tree */
vma_interval_tree_insert_after(struct vm_area_struct * node,struct vm_area_struct * prev,struct rb_root * root)29 void vma_interval_tree_insert_after(struct vm_area_struct *node,
30 struct vm_area_struct *prev,
31 struct rb_root *root)
32 {
33 struct rb_node **link;
34 struct vm_area_struct *parent;
35 unsigned long last = vma_last_pgoff(node);
36
37 VM_BUG_ON_VMA(vma_start_pgoff(node) != vma_start_pgoff(prev), node);
38
39 if (!prev->shared.rb.rb_right) {
40 parent = prev;
41 link = &prev->shared.rb.rb_right;
42 } else {
43 parent = rb_entry(prev->shared.rb.rb_right,
44 struct vm_area_struct, shared.rb);
45 if (parent->shared.rb_subtree_last < last)
46 parent->shared.rb_subtree_last = last;
47 while (parent->shared.rb.rb_left) {
48 parent = rb_entry(parent->shared.rb.rb_left,
49 struct vm_area_struct, shared.rb);
50 if (parent->shared.rb_subtree_last < last)
51 parent->shared.rb_subtree_last = last;
52 }
53 link = &parent->shared.rb.rb_left;
54 }
55
56 node->shared.rb_subtree_last = last;
57 rb_link_node(&node->shared.rb, &parent->shared.rb, link);
58 rb_insert_augmented(&node->shared.rb, root,
59 &vma_interval_tree_augment);
60 }
61
avc_start_pgoff(struct anon_vma_chain * avc)62 static inline unsigned long avc_start_pgoff(struct anon_vma_chain *avc)
63 {
64 return vma_start_pgoff(avc->vma);
65 }
66
avc_last_pgoff(struct anon_vma_chain * avc)67 static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc)
68 {
69 return vma_last_pgoff(avc->vma);
70 }
71
INTERVAL_TREE_DEFINE(struct anon_vma_chain,rb,unsigned long,rb_subtree_last,avc_start_pgoff,avc_last_pgoff,static inline,__anon_vma_interval_tree)72 INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last,
73 avc_start_pgoff, avc_last_pgoff,
74 static inline, __anon_vma_interval_tree)
75
76 void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
77 struct rb_root *root)
78 {
79 #ifdef CONFIG_DEBUG_VM_RB
80 node->cached_vma_start = avc_start_pgoff(node);
81 node->cached_vma_last = avc_last_pgoff(node);
82 #endif
83 __anon_vma_interval_tree_insert(node, root);
84 }
85
anon_vma_interval_tree_remove(struct anon_vma_chain * node,struct rb_root * root)86 void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
87 struct rb_root *root)
88 {
89 __anon_vma_interval_tree_remove(node, root);
90 }
91
92 struct anon_vma_chain *
anon_vma_interval_tree_iter_first(struct rb_root * root,unsigned long first,unsigned long last)93 anon_vma_interval_tree_iter_first(struct rb_root *root,
94 unsigned long first, unsigned long last)
95 {
96 return __anon_vma_interval_tree_iter_first(root, first, last);
97 }
98
99 struct anon_vma_chain *
anon_vma_interval_tree_iter_next(struct anon_vma_chain * node,unsigned long first,unsigned long last)100 anon_vma_interval_tree_iter_next(struct anon_vma_chain *node,
101 unsigned long first, unsigned long last)
102 {
103 return __anon_vma_interval_tree_iter_next(node, first, last);
104 }
105
106 #ifdef CONFIG_DEBUG_VM_RB
anon_vma_interval_tree_verify(struct anon_vma_chain * node)107 void anon_vma_interval_tree_verify(struct anon_vma_chain *node)
108 {
109 WARN_ON_ONCE(node->cached_vma_start != avc_start_pgoff(node));
110 WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node));
111 }
112 #endif
113