60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/*
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* mm/interval_tree.c - interval tree for mapping->i_mmap
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*
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* Copyright (C) 2012, Michel Lespinasse <walken@google.com>
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*
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* This file is released under the GPL v2.
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*/
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/interval_tree_generic.h>
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static inline unsigned long vma_start_pgoff(struct vm_area_struct *v)
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{
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return v->vm_pgoff;
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}
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static inline unsigned long vma_last_pgoff(struct vm_area_struct *v)
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{
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return v->vm_pgoff + ((v->vm_end - v->vm_start) >> PAGE_SHIFT) - 1;
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}
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INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.linear.rb,
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unsigned long, shared.linear.rb_subtree_last,
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vma_start_pgoff, vma_last_pgoff,, vma_interval_tree)
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/* Insert node immediately after prev in the interval tree */
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void vma_interval_tree_insert_after(struct vm_area_struct *node,
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struct vm_area_struct *prev,
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struct rb_root *root)
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{
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struct rb_node **link;
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struct vm_area_struct *parent;
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unsigned long last = vma_last_pgoff(node);
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VM_BUG_ON(vma_start_pgoff(node) != vma_start_pgoff(prev));
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if (!prev->shared.linear.rb.rb_right) {
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parent = prev;
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link = &prev->shared.linear.rb.rb_right;
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} else {
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parent = rb_entry(prev->shared.linear.rb.rb_right,
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struct vm_area_struct, shared.linear.rb);
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if (parent->shared.linear.rb_subtree_last < last)
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parent->shared.linear.rb_subtree_last = last;
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while (parent->shared.linear.rb.rb_left) {
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parent = rb_entry(parent->shared.linear.rb.rb_left,
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struct vm_area_struct, shared.linear.rb);
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if (parent->shared.linear.rb_subtree_last < last)
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parent->shared.linear.rb_subtree_last = last;
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}
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link = &parent->shared.linear.rb.rb_left;
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}
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node->shared.linear.rb_subtree_last = last;
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rb_link_node(&node->shared.linear.rb, &parent->shared.linear.rb, link);
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rb_insert_augmented(&node->shared.linear.rb, root,
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&vma_interval_tree_augment);
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}
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