On Thu, Mar 09, 2023 at 12:12:56PM +0100, Vlastimil Babka wrote:
> The comments already mention returning 'true' so make the code match
> them.
>
> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
> mm/mmap.c | 53 +++++++++++++++++++++++++----------------------------
> 1 file changed, 25 insertions(+), 28 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index c51d69592e4e..d20bbe9ec613 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 +758,20 @@ 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 +779,7 @@ 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;
> }
>
> @@ -795,19 +794,18 @@ 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,
> - struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
> - struct anon_vma_name *anon_name)
> + struct anon_vma *anon_vma, struct file *file,
> + pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
> + struct anon_vma_name *anon_name)
> {
> 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;
> }
>
> /*
> @@ -817,21 +815,20 @@ 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,
> - struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
> - struct anon_vma_name *anon_name)
> + struct anon_vma *anon_vma, struct file *file,
> + pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
> + struct anon_vma_name *anon_name)
> {
> if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
> is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
> 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
>
Partying like it's C99 :) Good improvement, feels sensible to move on from using
return types as if the 1st edition of The C Programming Language were still
current! Therefore,
Reviewed-By: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
