1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * mm/interval_tree.c - interval tree for address_space->i_mmap and 4 * anon_vma->rb_root 5 * 6 * Copyright (C) 2012, Michel Lespinasse <walken@google.com> 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 14 /* File-backed interval tree (address_space->i_mmap) */ 15 16 INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb, 17 pgoff_t, shared.rb_subtree_last, 18 vma_start_pgoff, vma_last_pgoff, static, 19 __mapping_rmap_tree) 20 21 void mapping_rmap_tree_insert(struct vm_area_struct *vma, 22 struct address_space *mapping) 23 { 24 __mapping_rmap_tree_insert(vma, &mapping->i_mmap); 25 } 26 27 /* Insert vma immediately after prev in the interval tree */ 28 void mapping_rmap_tree_insert_after(struct vm_area_struct *vma, 29 struct vm_area_struct *prev, 30 struct address_space *mapping) 31 { 32 struct rb_node **link; 33 struct vm_area_struct *parent; 34 const pgoff_t pgoff_last = vma_last_pgoff(vma); 35 36 VM_WARN_ON_ONCE_VMA(vma_start_pgoff(vma) != vma_start_pgoff(prev), vma); 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 < pgoff_last) 45 parent->shared.rb_subtree_last = pgoff_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 < pgoff_last) 50 parent->shared.rb_subtree_last = pgoff_last; 51 } 52 link = &parent->shared.rb.rb_left; 53 } 54 55 vma->shared.rb_subtree_last = pgoff_last; 56 rb_link_node(&vma->shared.rb, &parent->shared.rb, link); 57 rb_insert_augmented(&vma->shared.rb, &mapping->i_mmap.rb_root, 58 &__mapping_rmap_tree_augment); 59 } 60 61 void mapping_rmap_tree_remove(struct vm_area_struct *vma, 62 struct address_space *mapping) 63 { 64 __mapping_rmap_tree_remove(vma, &mapping->i_mmap); 65 } 66 67 struct vm_area_struct * 68 mapping_rmap_tree_iter_first(struct address_space *mapping, 69 pgoff_t pgoff_start, pgoff_t pgoff_last) 70 { 71 return __mapping_rmap_tree_iter_first(&mapping->i_mmap, 72 pgoff_start, pgoff_last); 73 } 74 75 struct vm_area_struct * 76 mapping_rmap_tree_iter_next(struct vm_area_struct *vma, 77 pgoff_t pgoff_start, pgoff_t pgoff_last) 78 { 79 return __mapping_rmap_tree_iter_next(vma, pgoff_start, pgoff_last); 80 } 81 82 /* Anonymous interval tree (anon_vma->rb_root) */ 83 84 static pgoff_t avc_start_pgoff(struct anon_vma_chain *avc) 85 { 86 return vma_start_anon_pgoff(avc->vma); 87 } 88 89 static pgoff_t avc_last_pgoff(struct anon_vma_chain *avc) 90 { 91 return vma_last_anon_pgoff(avc->vma); 92 } 93 94 INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, pgoff_t, rb_subtree_last, 95 avc_start_pgoff, avc_last_pgoff, 96 static, __anon_rmap_tree) 97 98 void anon_rmap_tree_insert(struct anon_vma_chain *avc, 99 struct anon_vma *anon_vma) 100 { 101 #ifdef CONFIG_DEBUG_VM_RB 102 avc->cached_vma_start = avc_start_pgoff(avc); 103 avc->cached_vma_last = avc_last_pgoff(avc); 104 #endif 105 __anon_rmap_tree_insert(avc, &anon_vma->rb_root); 106 } 107 108 void anon_rmap_tree_remove(struct anon_vma_chain *avc, 109 struct anon_vma *anon_vma) 110 { 111 __anon_rmap_tree_remove(avc, &anon_vma->rb_root); 112 } 113 114 struct anon_vma_chain * 115 anon_rmap_tree_iter_first(struct anon_vma *anon_vma, 116 pgoff_t pgoff_start, pgoff_t pgoff_last) 117 { 118 return __anon_rmap_tree_iter_first(&anon_vma->rb_root, 119 pgoff_start, pgoff_last); 120 } 121 122 struct anon_vma_chain * 123 anon_rmap_tree_iter_next(struct anon_vma_chain *avc, 124 pgoff_t pgoff_start, pgoff_t pgoff_last) 125 { 126 return __anon_rmap_tree_iter_next(avc, pgoff_start, pgoff_last); 127 } 128 129 #ifdef CONFIG_DEBUG_VM_RB 130 void anon_rmap_tree_verify(struct anon_vma_chain *avc) 131 { 132 WARN_ON_ONCE(avc->cached_vma_start != avc_start_pgoff(avc)); 133 WARN_ON_ONCE(avc->cached_vma_last != avc_last_pgoff(avc)); 134 } 135 #endif 136