1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * mm/interval_tree.c - interval tree for mapping->i_mmap 4 * 5 * Copyright (C) 2012, Michel Lespinasse <walken@google.com> 6 */ 7 8 #include <linux/mm.h> 9 #include <linux/fs.h> 10 #include <linux/rmap.h> 11 #include <linux/interval_tree_generic.h> 12 13 static inline unsigned long vma_start_pgoff(struct vm_area_struct *v) 14 { 15 return v->vm_pgoff; 16 } 17 18 static inline unsigned long vma_last_pgoff(struct vm_area_struct *v) 19 { 20 return v->vm_pgoff + vma_pages(v) - 1; 21 } 22 23 INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb, 24 unsigned long, shared.rb_subtree_last, 25 vma_start_pgoff, vma_last_pgoff, /* empty */, vma_interval_tree) 26 27 /* Insert node immediately after prev in the interval tree */ 28 void vma_interval_tree_insert_after(struct vm_area_struct *node, 29 struct vm_area_struct *prev, 30 struct rb_root_cached *root) 31 { 32 struct rb_node **link; 33 struct vm_area_struct *parent; 34 unsigned long last = vma_last_pgoff(node); 35 36 VM_BUG_ON_VMA(vma_start_pgoff(node) != vma_start_pgoff(prev), node); 37 38 if (!prev->shared.rb.rb_right) { 39 parent = prev; 40 link = &prev->shared.rb.rb_right; 41 } else { 42 parent = rb_entry(prev->shared.rb.rb_right, 43 struct vm_area_struct, shared.rb); 44 if (parent->shared.rb_subtree_last < last) 45 parent->shared.rb_subtree_last = last; 46 while (parent->shared.rb.rb_left) { 47 parent = rb_entry(parent->shared.rb.rb_left, 48 struct vm_area_struct, shared.rb); 49 if (parent->shared.rb_subtree_last < last) 50 parent->shared.rb_subtree_last = last; 51 } 52 link = &parent->shared.rb.rb_left; 53 } 54 55 node->shared.rb_subtree_last = last; 56 rb_link_node(&node->shared.rb, &parent->shared.rb, link); 57 rb_insert_augmented(&node->shared.rb, &root->rb_root, 58 &vma_interval_tree_augment); 59 } 60 61 static inline unsigned long avc_start_pgoff(struct anon_vma_chain *avc) 62 { 63 return vma_start_pgoff(avc->vma); 64 } 65 66 static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc) 67 { 68 return vma_last_pgoff(avc->vma); 69 } 70 71 INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last, 72 avc_start_pgoff, avc_last_pgoff, 73 static inline, __anon_vma_interval_tree) 74 75 void anon_vma_interval_tree_insert(struct anon_vma_chain *node, 76 struct rb_root_cached *root) 77 { 78 #ifdef CONFIG_DEBUG_VM_RB 79 node->cached_vma_start = avc_start_pgoff(node); 80 node->cached_vma_last = avc_last_pgoff(node); 81 #endif 82 __anon_vma_interval_tree_insert(node, root); 83 } 84 85 void anon_vma_interval_tree_remove(struct anon_vma_chain *node, 86 struct rb_root_cached *root) 87 { 88 __anon_vma_interval_tree_remove(node, root); 89 } 90 91 struct anon_vma_chain * 92 anon_vma_interval_tree_iter_first(struct rb_root_cached *root, 93 unsigned long first, unsigned long last) 94 { 95 return __anon_vma_interval_tree_iter_first(root, first, last); 96 } 97 98 struct anon_vma_chain * 99 anon_vma_interval_tree_iter_next(struct anon_vma_chain *node, 100 unsigned long first, unsigned long last) 101 { 102 return __anon_vma_interval_tree_iter_next(node, first, last); 103 } 104 105 #ifdef CONFIG_DEBUG_VM_RB 106 void anon_vma_interval_tree_verify(struct anon_vma_chain *node) 107 { 108 WARN_ON_ONCE(node->cached_vma_start != avc_start_pgoff(node)); 109 WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node)); 110 } 111 #endif 112