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: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 72142fb..ed68bdf 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -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 @@ replace:
                        goto out;
 next:
                prev = vma;
-       }
+       } for_each_vma_range(vmi, vma, end);
 
 out:
        return err;