Commit 2dbf4010 authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Andrew Morton
Browse files

mm/mmap/vma_merge: convert mergeability checks to return bool 

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

Link: https://lkml.kernel.org/r/20230309111258.24079-9-vbabka@suse.cz


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1e76454f

mm/mmap.c

+25 −28
Original line number Diff line number Diff line
@@ -744,7 +744,7 @@ 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,

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)
@@ -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,

		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;

}



/*
@@ -817,11 +815,10 @@ 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,

		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) &&
@@ -829,9 +826,9 @@ 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;

}



/*