mm: expand vma iterator interface

Add wrappers for the maple tree to the vma iterator.  This will provide
type safety at compile time.

Link: https://lkml.kernel.org/r/20230120162650.984577-8-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index ffc0815cd7fb71..db70f3e2181e16 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -144,6 +144,24 @@ static void remove_vma(struct vm_area_struct *vma)
 	vm_area_free(vma);
 }
 
+static inline struct vm_area_struct *vma_prev_limit(struct vma_iterator *vmi,
+						    unsigned long min)
+{
+	return mas_prev(&vmi->mas, min);
+}
+
+static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,
+			unsigned long start, unsigned long end, gfp_t gfp)
+{
+	vmi->mas.index = start;
+	vmi->mas.last = end - 1;
+	mas_store_gfp(&vmi->mas, NULL, gfp);
+	if (unlikely(mas_is_err(&vmi->mas)))
+		return -ENOMEM;
+
+	return 0;
+}
+
 /*
  * check_brk_limits() - Use platform specific check of range & verify mlock
  * limits.