Change the implementation of find_vma_prev to use the new maple tree
data structure.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mmap.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index ab1cb0efc4c65..f123f9c97dfe8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2500,23 +2500,30 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
}
EXPORT_SYMBOL(find_vma);
-/*
- * Same as find_vma, but also return a pointer to the previous VMA in *pprev.
+/**
+ * find_vma_prev() - Find the VMA for a given address, or the next vma and
+ * sets %pprev to the previous VMA, if any.
+ * @mm The mm_struct to check
+ * @addr: The address
+ * @pprev: The pointer to set to the previous VMA
+ *
+ * Returns: The VMA associated with @addr, or the next vma.
+ * May return NULL in the case of no vma at addr or above.
*/
struct vm_area_struct *
find_vma_prev(struct mm_struct *mm, unsigned long addr,
- struct vm_area_struct **pprev)
+ struct vm_area_struct **pprev)
{
struct vm_area_struct *vma;
+ MA_STATE(mas, &mm->mm_mt, addr, addr);
- vma = find_vma(mm, addr);
- if (vma) {
- *pprev = vma->vm_prev;
- } else {
- struct rb_node *rb_node = rb_last(&mm->mm_rb);
+ rcu_read_lock();
+ vma = mas_find(&mas, ULONG_MAX);
+ if (!vma)
+ mas_reset(&mas);
- *pprev = rb_node ? rb_entry(rb_node, struct vm_area_struct, vm_rb) : NULL;
- }
+ *pprev = mas_prev(&mas, 0);
+ rcu_read_unlock();
return vma;
}
--
2.28.0
