[RFC 09/11] mm/mmap/vma_merge: convert mergeability checks to return bool

From: Vlastimil Babka
Date: Fri Feb 24 2023 - 05:01:21 EST


The comments already mention returning 'true' so make the code match
them.

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/mmap.c | 40 ++++++++++++++++++++--------------------
1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 8c2bdf9e3f94..6e439806d4ac 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -744,10 +744,10 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
* If the vma has a ->close operation then the driver probably needs to release
* per-vma resources, so we don't attempt to merge those.
*/
-static inline int is_mergeable_vma(struct vm_area_struct *vma,
- struct file *file, unsigned long vm_flags,
- struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
- struct anon_vma_name *anon_name)
+static inline bool is_mergeable_vma(struct vm_area_struct *vma,
+ struct file *file, unsigned long vm_flags,
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+ struct anon_vma_name *anon_name)
{
/*
* VM_SOFTDIRTY should not prevent from VMA merging, if we
@@ -758,21 +758,21 @@ static inline int is_mergeable_vma(struct vm_area_struct *vma,
* extended instead.
*/
if ((vma->vm_flags ^ vm_flags) & ~VM_SOFTDIRTY)
- return 0;
+ return false;
if (vma->vm_file != file)
- return 0;
+ return false;
if (vma->vm_ops && vma->vm_ops->close)
- return 0;
+ return false;
if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
- return 0;
+ return false;
if (!anon_vma_name_eq(anon_vma_name(vma), anon_name))
- return 0;
- return 1;
+ return false;
+ return true;
}

-static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1,
- struct anon_vma *anon_vma2,
- struct vm_area_struct *vma)
+static inline bool is_mergeable_anon_vma(struct anon_vma *anon_vma1,
+ struct anon_vma *anon_vma2,
+ struct vm_area_struct *vma)
{
/*
* The list_is_singular() test is to avoid merging VMA cloned from
@@ -780,7 +780,7 @@ static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1,
*/
if ((!anon_vma1 || !anon_vma2) && (!vma ||
list_is_singular(&vma->anon_vma_chain)))
- return 1;
+ return true;
return anon_vma1 == anon_vma2;
}

@@ -795,7 +795,7 @@ static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1,
* indices (16TB on ia32) because do_mmap() does not permit mmap's which
* wrap, nor mmaps which cover the final page at index -1UL.
*/
-static int
+static bool
can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t vm_pgoff,
@@ -805,9 +805,9 @@ can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
- return 1;
+ return true;
}
- return 0;
+ return false;
}

/*
@@ -817,7 +817,7 @@ can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
* We cannot merge two vmas if they have differently assigned (non-NULL)
* anon_vmas, nor if same anon_vma is assigned but offsets incompatible.
*/
-static int
+static bool
can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t vm_pgoff,
@@ -829,9 +829,9 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
pgoff_t vm_pglen;
vm_pglen = vma_pages(vma);
if (vma->vm_pgoff + vm_pglen == vm_pgoff)
- return 1;
+ return true;
}
- return 0;
+ return false;
}

/*
--
2.39.2