From c4d1a92d0d3ada8a4073b8af8eff462d689d64c5 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Tue, 6 Sep 2022 19:49:00 +0000
Subject: [PATCH] mm/gup: use maple tree navigation instead of linked list

Use find_vma_intersection() to locate the VMAs in __mm_populate() instead
of using find_vma() and the linked list.

Link: https://lkml.kernel.org/r/20220906194824.2110408-52-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/gup.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index d4f706dc245f..6e49fe5da513 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1674,10 +1674,11 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
 		if (!locked) {
 			locked = 1;
 			mmap_read_lock(mm);
-			vma = find_vma(mm, nstart);
+			vma = find_vma_intersection(mm, nstart, end);
 		} else if (nstart >= vma->vm_end)
-			vma = vma->vm_next;
-		if (!vma || vma->vm_start >= end)
+			vma = find_vma_intersection(mm, vma->vm_end, end);
+
+		if (!vma)
 			break;
 		/*
 		 * Set [nstart; nend) to intersection of desired address