From: Liam Howlett <Liam.Howlett@oracle.com>
Date: Mon, 14 Nov 2022 16:08:16 +0000 (-0500)
Subject: mm: Remove unnecessary write to vma iterator in __vma_adjust()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8c6306f42bfd14fdb95b83299d6532e08ca8c1c6;p=users%2Fjedix%2Flinux-maple.git

mm: Remove unnecessary write to vma iterator in __vma_adjust()

If the vma start address is going to change due to an insert, then it is
safe to not write the vma to the tree.  The write of the insert vma will
alter the tree as necessary.

Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index 0e6f0705d81a..07849eb492e0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -705,10 +705,12 @@ int __vma_adjust(struct vma_iterator *vmi, struct vm_area_struct *vma,
 	}
 
 	if (start != vma->vm_start) {
-		if ((vma->vm_start < start) &&
-		    (!insert || (insert->vm_end != start))) {
-			vma_iter_clear(vmi, vma->vm_start, start);
-			VM_WARN_ON(insert && insert->vm_start > vma->vm_start);
+		if (vma->vm_start < start) {
+			if (!insert || (insert->vm_end != start)) {
+				vma_iter_clear(vmi, vma->vm_start, start);
+				vma_iter_set(vmi, start);
+				VM_WARN_ON(insert && insert->vm_start > vma->vm_start);
+			}
 		} else {
 			vma_changed = true;
 		}