ksm: cleanup: introduce find_mergeable_vma()
There are multiple places which perform the same check. Add a new
find_mergeable_vma() to handle this.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/ksm.c b/mm/ksm.c
index a6d3fb7..47c8853 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -374,6 +374,20 @@
return (ret & VM_FAULT_OOM) ? -ENOMEM : 0;
}
+static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm,
+ unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ if (ksm_test_exit(mm))
+ return NULL;
+ vma = find_vma(mm, addr);
+ if (!vma || vma->vm_start > addr)
+ return NULL;
+ if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+ return NULL;
+ return vma;
+}
+
static void break_cow(struct rmap_item *rmap_item)
{
struct mm_struct *mm = rmap_item->mm;
@@ -387,15 +401,9 @@
put_anon_vma(rmap_item->anon_vma);
down_read(&mm->mmap_sem);
- if (ksm_test_exit(mm))
- goto out;
- vma = find_vma(mm, addr);
- if (!vma || vma->vm_start > addr)
- goto out;
- if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
- goto out;
- break_ksm(vma, addr);
-out:
+ vma = find_mergeable_vma(mm, addr);
+ if (vma)
+ break_ksm(vma, addr);
up_read(&mm->mmap_sem);
}
@@ -421,12 +429,8 @@
struct page *page;
down_read(&mm->mmap_sem);
- if (ksm_test_exit(mm))
- goto out;
- vma = find_vma(mm, addr);
- if (!vma || vma->vm_start > addr)
- goto out;
- if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+ vma = find_mergeable_vma(mm, addr);
+ if (!vma)
goto out;
page = follow_page(vma, addr, FOLL_GET);