[102/192] mm/mmap: introduce unlock_range() for code cleanup

Commit Message

Andrew Morton June 29, 2021, 2:38 a.m. UTC

From: Liam Howlett <[e-mail]>
Subject: mm/mmap: introduce unlock_range() for code cleanup

Both __do_munmap() and exit_mmap() unlock a range of VMAs using almost
identical code blocks.  Replace both blocks by a static inline function.

[[e-mail]: tweak code layout]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Liam R. Howlett <[e-mail]>
Reviewed-by: Matthew Wilcox (Oracle) <[e-mail]>
Reviewed-by: Davidlohr Bueso <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/mmap.c |   39 ++++++++++++++++++++-------------------
 1 file changed, 20 insertions(+), 19 deletions(-)

Patch

--- a/mm/mmap.c~mm-mmap-introduce-unlock_range-for-code-cleanup
+++ a/mm/mmap.c
@@ -2802,6 +2802,22 @@  int split_vma(struct mm_struct *mm, stru
 	return __split_vma(mm, vma, addr, new_below);
 }
 
+static inline void
+unlock_range(struct vm_area_struct *start, unsigned long limit)
+{
+	struct mm_struct *mm = start->vm_mm;
+	struct vm_area_struct *tmp = start;
+
+	while (tmp && tmp->vm_start < limit) {
+		if (tmp->vm_flags & VM_LOCKED) {
+			mm->locked_vm -= vma_pages(tmp);
+			munlock_vma_pages_all(tmp);
+		}
+
+		tmp = tmp->vm_next;
+	}
+}
+
 /* Munmap is split into 2 main parts -- this part which finds
  * what needs doing, and the areas themselves, which do the
  * work.  This now handles partial unmappings.
@@ -2885,17 +2901,8 @@  int __do_munmap(struct mm_struct *mm, un
 	/*
 	 * unlock any mlock()ed ranges before detaching vmas
 	 */
-	if (mm->locked_vm) {
-		struct vm_area_struct *tmp = vma;
-		while (tmp && tmp->vm_start < end) {
-			if (tmp->vm_flags & VM_LOCKED) {
-				mm->locked_vm -= vma_pages(tmp);
-				munlock_vma_pages_all(tmp);
-			}
-
-			tmp = tmp->vm_next;
-		}
-	}
+	if (mm->locked_vm)
+		unlock_range(vma, end);
 
 	/* Detach vmas from rbtree */
 	if (!detach_vmas_to_be_unmapped(mm, vma, prev, end))
@@ -3180,14 +3187,8 @@  void exit_mmap(struct mm_struct *mm)
 		mmap_write_unlock(mm);
 	}
 
-	if (mm->locked_vm) {
-		vma = mm->mmap;
-		while (vma) {
-			if (vma->vm_flags & VM_LOCKED)
-				munlock_vma_pages_all(vma);
-			vma = vma->vm_next;
-		}
-	}
+	if (mm->locked_vm)
+		unlock_range(mm->mmap, ULONG_MAX);
 
 	arch_exit_mmap(mm);