62 lines
1.8 KiB
C
62 lines
1.8 KiB
C
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/*
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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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#define ITSTRUCT struct vm_area_struct
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#define ITRB shared.linear.rb
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#define ITTYPE unsigned long
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#define ITSUBTREE shared.linear.rb_subtree_last
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#define ITSTART(n) ((n)->vm_pgoff)
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#define ITLAST(n) ((n)->vm_pgoff + \
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(((n)->vm_end - (n)->vm_start) >> PAGE_SHIFT) - 1)
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#define ITSTATIC
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#define ITPREFIX vma_interval_tree
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#include <linux/interval_tree_tmpl.h>
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/* Insert old immediately after vma in the interval tree */
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void vma_interval_tree_add(struct vm_area_struct *vma,
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struct vm_area_struct *old,
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struct address_space *mapping)
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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;
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if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
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list_add(&vma->shared.nonlinear, &old->shared.nonlinear);
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return;
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}
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last = ITLAST(vma);
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if (!old->shared.linear.rb.rb_right) {
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parent = old;
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link = &old->shared.linear.rb.rb_right;
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} else {
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parent = rb_entry(old->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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vma->shared.linear.rb_subtree_last = last;
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rb_link_node(&vma->shared.linear.rb, &parent->shared.linear.rb, link);
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rb_insert_augmented(&vma->shared.linear.rb, &mapping->i_mmap,
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&vma_interval_tree_augment_callbacks);
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}
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