Commit f10c2abc authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

mempolicy: convert to vma iterator 

Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.

Link: https://lkml.kernel.org/r/20230120162650.984577-21-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e552cdb8

mm/mempolicy.c

+8 −17
Original line number Diff line number Diff line
@@ -787,24 +787,21 @@ static int vma_replace_policy(struct vm_area_struct *vma, 
static int mbind_range(struct mm_struct *mm, unsigned long start,

		       unsigned long end, struct mempolicy *new_pol)

{

	MA_STATE(mas, &mm->mm_mt, start, start);

	VMA_ITERATOR(vmi, mm, start);

	struct vm_area_struct *prev;

	struct vm_area_struct *vma;

	int err = 0;

	pgoff_t pgoff;



	prev = mas_prev(&mas, 0);

	if (unlikely(!prev))

		mas_set(&mas, start);



	vma = mas_find(&mas, end - 1);

	prev = vma_prev(&vmi);

	vma = vma_find(&vmi, end);

	if (WARN_ON(!vma))

		return 0;



	if (start > vma->vm_start)

		prev = vma;



	for (; vma; vma = mas_next(&mas, end - 1)) {

	do {

		unsigned long vmstart = max(start, vma->vm_start);

		unsigned long vmend = min(end, vma->vm_end);
@@ -813,29 +810,23 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, 


		pgoff = vma->vm_pgoff +

			((vmstart - vma->vm_start) >> PAGE_SHIFT);

		prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,

		prev = vmi_vma_merge(&vmi, mm, prev, vmstart, vmend, vma->vm_flags,

				 vma->anon_vma, vma->vm_file, pgoff,

				 new_pol, vma->vm_userfaultfd_ctx,

				 anon_vma_name(vma));

		if (prev) {

			/* vma_merge() invalidated the mas */

			mas_pause(&mas);

			vma = prev;

			goto replace;

		}

		if (vma->vm_start != vmstart) {

			err = split_vma(vma->vm_mm, vma, vmstart, 1);

			err = vmi_split_vma(&vmi, vma->vm_mm, vma, vmstart, 1);

			if (err)

				goto out;

			/* split_vma() invalidated the mas */

			mas_pause(&mas);

		}

		if (vma->vm_end != vmend) {

			err = split_vma(vma->vm_mm, vma, vmend, 0);

			err = vmi_split_vma(&vmi, vma->vm_mm, vma, vmend, 0);

			if (err)

				goto out;

			/* split_vma() invalidated the mas */

			mas_pause(&mas);

		}

replace:

		err = vma_replace_policy(vma, new_pol);
@@ -843,7 +834,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, 
			goto out;

next:

		prev = vma;

	}

	} for_each_vma_range(vmi, vma, end);



out:

	return err;