From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Thu, 21 Apr 2022 22:00:09 +0000 (-0400)
Subject: convert vma_expand() to prealloc
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1797ae91c515ee03e5ad60c13de1703426a18c95;p=users%2Fjedix%2Flinux-maple.git

convert vma_expand() to prealloc

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

diff --git a/mm/mmap.c b/mm/mmap.c
index 2aa27adb39b1..4ef7d19e9ca8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -559,6 +559,7 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
 	struct anon_vma *anon_vma = vma->anon_vma;
 	struct file *file = vma->vm_file;
 	bool remove_next = false;
+	bool anon_cloned = false;
 
 	if (next && (vma != next) && (end == next->vm_end)) {
 		remove_next = true;
@@ -569,6 +570,7 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
 			error = anon_vma_clone(vma, next);
 			if (error)
 				return error;
+			anon_cloned = true;
 		}
 	}
 
@@ -577,6 +579,9 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
 	/* Only handles expanding */
 	VM_BUG_ON(vma->vm_start < start || vma->vm_end > end);
 
+	if (mas_preallocate(mas, vma, GFP_KERNEL))
+		goto nomem;
+
 	vma_adjust_trans_huge(vma, start, end, 0);
 
 	if (file) {
@@ -631,6 +636,11 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
 
 	validate_mm(mm);
 	return 0;
+
+nomem:
+	if (anon_cloned)
+		unlink_anon_vmas(vma);
+	return -ENOMEM;
 }
 
 /*