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 INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb, 19 unsigned long, shared.rb_subtree_last, 20 vma_start_pgoff, vma_last_pgoff, /* empty */, vma_interval_tree) 21 22 /* Insert node immediately after prev in the interval tree */ 23 void vma_interval_tree_insert_after(struct vm_area_struct *node, 24 struct vm_area_struct *prev, 25 struct rb_root_cached *root) 26 { 27 struct rb_node **link; 28 struct vm_area_struct *parent; 29 unsigned long last = vma_last_pgoff(node); 30 31 VM_BUG_ON_VMA(vma_start_pgoff(node) != vma_start_pgoff(prev), node); 32 33 if (!prev->shared.rb.rb_right) { 34 parent = prev; 35 link = &prev->shared.rb.rb_right; 36 } else { 37 parent = rb_entry(prev->shared.rb.rb_right, 38 struct vm_area_struct, shared.rb); 39 if (parent->shared.rb_subtree_last < last) 40 parent->shared.rb_subtree_last = last; 41 while (parent->shared.rb.rb_left) { 42 parent = rb_entry(parent->shared.rb.rb_left, 43 struct vm_area_struct, shared.rb); 44 if (parent->shared.rb_subtree_last < last) 45 parent->shared.rb_subtree_last = last; 46 } 47 link = &parent->shared.rb.rb_left; 48 } 49 50 node->shared.rb_subtree_last = last; 51 rb_link_node(&node->shared.rb, &parent->shared.rb, link); 52 rb_insert_augmented(&node->shared.rb, &root->rb_root, 53 &vma_interval_tree_augment); 54 } 55 56 static inline unsigned long avc_start_pgoff(struct anon_vma_chain *avc) 57 { 58 return vma_start_pgoff(avc->vma); 59 } 60 61 static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc) 62 { 63 return vma_last_pgoff(avc->vma); 64 } 65 66 INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last, 67 avc_start_pgoff, avc_last_pgoff, 68 static inline, __anon_vma_interval_tree) 69 70 void anon_vma_interval_tree_insert(struct anon_vma_chain *node, 71 struct rb_root_cached *root) 72 { 73 #ifdef CONFIG_DEBUG_VM_RB 74 node->cached_vma_start = avc_start_pgoff(node); 75 node->cached_vma_last = avc_last_pgoff(node); 76 #endif 77 __anon_vma_interval_tree_insert(node, root); 78 } 79 80 void anon_vma_interval_tree_remove(struct anon_vma_chain *node, 81 struct rb_root_cached *root) 82 { 83 __anon_vma_interval_tree_remove(node, root); 84 } 85 86 struct anon_vma_chain * 87 anon_vma_interval_tree_iter_first(struct rb_root_cached *root, 88 unsigned long first, unsigned long last) 89 { 90 return __anon_vma_interval_tree_iter_first(root, first, last); 91 } 92 93 struct anon_vma_chain * 94 anon_vma_interval_tree_iter_next(struct anon_vma_chain *node, 95 unsigned long first, unsigned long last) 96 { 97 return __anon_vma_interval_tree_iter_next(node, first, last); 98 } 99 100 #ifdef CONFIG_DEBUG_VM_RB 101 void anon_vma_interval_tree_verify(struct anon_vma_chain *node) 102 { 103 WARN_ON_ONCE(node->cached_vma_start != avc_start_pgoff(node)); 104 WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node)); 105 } 106 #endif 107