From ee878dbb8db511da9b3ba50e738989c5afd4cfc0 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Mon, 4 Jan 2021 13:54:34 -0500
Subject: [PATCH] mm/mmap.c: Comment and whitespace fixes

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 mm/mmap.c | 45 +++++++++++++++++++++++++++++----------------
 1 file changed, 29 insertions(+), 16 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 1b20f042ea57..09fe2a96723d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -430,6 +430,16 @@ static void __vma_link_file(struct vm_area_struct *vma)
 	}
 }
 
+/*
+ * vma_mas_store() - Store a VMA in the maple tree.
+ * @vma: The vm_area_struct
+ * @mas: The maple state
+ *
+ * Efficient way to store a VMA in the maple tree when the @mas has already
+ * walked to the correct location.
+ *
+ * Note: the end address is inclusive in the maple tree.
+ */
 static inline int vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
 {
 	mas->index = vma->vm_start;
@@ -437,30 +447,31 @@ static inline int vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas
 	return mas_store_gfp(mas, vma, GFP_KERNEL);
 }
 
+/*
+ * vma_mas_remove() - Remove a VMA from the maple tree.
+ * @vma: The vm_area_struct
+ * @mas: The maple state
+ *
+ * Efficient way to remove a VMA from the maple tree when the @mas has already
+ * been established and points to the correct location.
+ * Note: the end address is inclusive in the maple tree.
+ */
 static inline int vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
 {
 	mas->index = vma->vm_start;
 	mas->last = vma->vm_end - 1;
 	return mas_store_gfp(mas, NULL, GFP_KERNEL);
 }
+
 /*
- * vma_mt_erase() - erase a VMA entry from the maple tree.
- *
- * @mm: The struct_mm
- * @vma: The vm_area_struct to erase from the maple tree.
- */
-static inline void vma_mt_erase(struct mm_struct *mm, struct vm_area_struct *vma)
-{
-	trace_vma_mt_erase(mm, vma);
-	mtree_erase(&mm->mm_mt, vma->vm_start);
-}
-/*
- * vma_mt_szero() - Set a given range to zero.  Used when modifying a
- * vm_area_struct start or end.
- *
+ * vma_mt_szero() - Clear a given range from the maple tree.
  * @mm: The struct_mm
  * @start: The start address to zero
  * @end: The end address to zero.
+ *
+ * Used when modifying a vm_area_struct start or end and there is no maple state
+ * pointing to the correct location.
+ * Note: the end address is inclusive in the maple tree.
  */
 static inline void vma_mt_szero(struct mm_struct *mm, unsigned long start,
 		unsigned long end)
@@ -470,9 +481,11 @@ static inline void vma_mt_szero(struct mm_struct *mm, unsigned long start,
 }
 /*
  * vma_mt_store() - Store a given vm_area_struct in the maple tree.
- *
  * @mm: The struct_mm
  * @vma: The vm_area_struct to store in the maple tree.
+ *
+ * Used when there is no maple state pointing to the correct location.
+ * Note: the end address is inclusive in the maple tree.
  */
 static inline void vma_mt_store(struct mm_struct *mm, struct vm_area_struct *vma)
 {
@@ -591,7 +604,6 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
 
 	/* Expanding over the next vma */
 	if (remove_next) {
-		/* Remove from mm linked list - also updates highest_vm_end */
 		if (file)
 			__remove_shared_vm_struct(next, file, mapping);
 	}
@@ -2201,6 +2213,7 @@ static void unmap_region(struct mm_struct *mm,
 		      max);
 	tlb_finish_mmu(&tlb, start, end);
 }
+
 /*
  * __split_vma() bypasses sysctl_max_map_count checking.  We use this where it
  * has already been checked or doesn't make sense to fail.
-- 
2.50.1