From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Fri, 5 Aug 2022 20:04:16 +0000 (-0400)
Subject: mm/mmap: move anon_vma setting in __vma_adjust()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=28c26c021d379f3618b9e57d73f9b1610ae46b85;p=users%2Fjedix%2Flinux-maple.git

mm/mmap: move anon_vma setting in __vma_adjust()

Move the anon_vma setting & warn_no up the function.  This is done to
clear up the locking later.

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

diff --git a/mm/mmap.c b/mm/mmap.c
index fd97e0f53fff..6747eadcc06c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -715,6 +715,14 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
 	if (mas_preallocate(&mas, vma, GFP_KERNEL))
 		return -ENOMEM;
 
+	anon_vma = vma->anon_vma;
+	if (!anon_vma && adjust_next)
+		anon_vma = next->anon_vma;
+
+	if (anon_vma)
+		VM_WARN_ON(adjust_next && next->anon_vma &&
+			   anon_vma != next->anon_vma);
+
 	vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
 	if (file) {
 		mapping = file->f_mapping;
@@ -736,12 +744,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
 		}
 	}
 
-	anon_vma = vma->anon_vma;
-	if (!anon_vma && adjust_next)
-		anon_vma = next->anon_vma;
 	if (anon_vma) {
-		VM_WARN_ON(adjust_next && next->anon_vma &&
-			   anon_vma != next->anon_vma);
 		anon_vma_lock_write(anon_vma);
 		anon_vma_interval_tree_pre_update_vma(vma);
 		if (adjust_next)