[PATCH 24/30] mm/vma: update vma_shrink() to not pass unnecessary pgoff parameter

[Lorenzo Stoakes]

vma_shrink() does not need to adjust vma->vm_pgoff, we were passing this
parameter solely to satisfy vma_set_range()'s requirement for pgoff being
specified.

Since vma_set_range() is now isolated to vma.c, we can simply introduce
__vma_set_range() which sets only vma->vm_[start, end], and invoke this
instead, removing pgoff from vma_shrink() altogether.

No functional change intended.

Signed-off-by: Lorenzo Stoakes <ljs@xxxxxxxxxx>
---
 mm/vma.c                        | 14 ++++++++++----
 mm/vma.h                        |  2 +-
 mm/vma_exec.c                   |  2 +-
 tools/testing/vma/tests/merge.c |  2 +-
 4 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/mm/vma.c b/mm/vma.c
index b16c5b20862f..e3355eab11f2 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -70,11 +70,17 @@ struct mmap_state {
 		.state = VMA_MERGE_START,				\
 	}
 
-static void vma_set_range(struct vm_area_struct *vma, unsigned long start,
-			  unsigned long end, pgoff_t pgoff)
+static void __vma_set_range(struct vm_area_struct *vma, unsigned long start,
+			    unsigned long end)
 {
 	vma->vm_start = start;
 	vma->vm_end = end;
+}
+
+static void vma_set_range(struct vm_area_struct *vma, unsigned long start,
+			  unsigned long end, pgoff_t pgoff)
+{
+	__vma_set_range(vma, start, end);
 	vma->vm_pgoff = pgoff;
 }
 
@@ -1289,7 +1295,7 @@ int vma_expand(struct vma_merge_struct *vmg)
  * Returns: 0 on success, -ENOMEM otherwise
  */
 int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
-	       unsigned long start, unsigned long end, pgoff_t pgoff)
+	       unsigned long start, unsigned long end)
 {
 	struct vma_prepare vp;
 
@@ -1310,7 +1316,7 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
 	vma_adjust_trans_huge(vma, start, end, NULL);
 
 	vma_iter_clear(vmi);
-	vma_set_range(vma, start, end, pgoff);
+	__vma_set_range(vma, start, end);
 	vma_complete(&vp, vmi, vma->vm_mm);
 	validate_mm(vma->vm_mm);
 	return 0;
diff --git a/mm/vma.h b/mm/vma.h
index 14f026bf3be4..9658e0c678ad 100644
--- a/mm/vma.h
+++ b/mm/vma.h
@@ -298,7 +298,7 @@ void validate_mm(struct mm_struct *mm);
 __must_check int vma_expand(struct vma_merge_struct *vmg);
 __must_check int vma_shrink(struct vma_iterator *vmi,
 		struct vm_area_struct *vma,
-		unsigned long start, unsigned long end, pgoff_t pgoff);
+		unsigned long start, unsigned long end);
 
 static inline int vma_iter_store_gfp(struct vma_iterator *vmi,
 			struct vm_area_struct *vma, gfp_t gfp)
diff --git a/mm/vma_exec.c b/mm/vma_exec.c
index e3644a3042e2..0107a6e3918c 100644
--- a/mm/vma_exec.c
+++ b/mm/vma_exec.c
@@ -89,7 +89,7 @@ int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift)
 
 	vma_prev(&vmi);
 	/* Shrink the vma to just the new range */
-	return vma_shrink(&vmi, vma, new_start, new_end, vma_start_pgoff(vma));
+	return vma_shrink(&vmi, vma, new_start, new_end);
 }
 
 /*
diff --git a/tools/testing/vma/tests/merge.c b/tools/testing/vma/tests/merge.c
index f8666a755749..04704d6eb426 100644
--- a/tools/testing/vma/tests/merge.c
+++ b/tools/testing/vma/tests/merge.c
@@ -227,7 +227,7 @@ static bool test_simple_shrink(void)
 
 	ASSERT_FALSE(attach_vma(&mm, vma));
 
-	ASSERT_FALSE(vma_shrink(&vmi, vma, 0, 0x1000, 0));
+	ASSERT_FALSE(vma_shrink(&vmi, vma, 0, 0x1000));
 
 	ASSERT_EQ(vma->vm_start, 0);
 	ASSERT_EQ(vma->vm_end, 0x1000);
-- 
2.54.0