[PATCH 1/4] thp: reduce indentation level in change_huge_pmd()

[Kirill A. Shutemov]

Restructure code in preparation for a fix.

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---
 mm/huge_memory.c | 52 ++++++++++++++++++++++++++--------------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 71e3dede95b4..e7ce73b2b208 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1722,37 +1722,37 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t 
*pmd,
 {
        struct mm_struct *mm = vma->vm_mm;
        spinlock_t *ptl;
-       int ret = 0;
+       pmd_t entry;
+       bool preserve_write;
+       int ret;
 
        ptl = __pmd_trans_huge_lock(pmd, vma);
-       if (ptl) {
-               pmd_t entry;
-               bool preserve_write = prot_numa && pmd_write(*pmd);
-               ret = 1;
+       if (!ptl)
+               return 0;
 
-               /*
-                * Avoid trapping faults against the zero page. The read-only
-                * data is likely to be read-cached on the local CPU and
-                * local/remote hits to the zero page are not interesting.
-                */
-               if (prot_numa && is_huge_zero_pmd(*pmd)) {
-                       spin_unlock(ptl);
-                       return ret;
-               }
+       preserve_write = prot_numa && pmd_write(*pmd);
+       ret = 1;
 
-               if (!prot_numa || !pmd_protnone(*pmd)) {
-                       entry = pmdp_huge_get_and_clear_notify(mm, addr, pmd);
-                       entry = pmd_modify(entry, newprot);
-                       if (preserve_write)
-                               entry = pmd_mk_savedwrite(entry);
-                       ret = HPAGE_PMD_NR;
-                       set_pmd_at(mm, addr, pmd, entry);
-                       BUG_ON(vma_is_anonymous(vma) && !preserve_write &&
-                                       pmd_write(entry));
-               }
-               spin_unlock(ptl);
-       }
+       /*
+        * Avoid trapping faults against the zero page. The read-only
+        * data is likely to be read-cached on the local CPU and
+        * local/remote hits to the zero page are not interesting.
+        */
+       if (prot_numa && is_huge_zero_pmd(*pmd))
+               goto unlock;
 
+       if (prot_numa && pmd_protnone(*pmd))
+               goto unlock;
+
+       entry = pmdp_huge_get_and_clear_notify(mm, addr, pmd);
+       entry = pmd_modify(entry, newprot);
+       if (preserve_write)
+               entry = pmd_mk_savedwrite(entry);
+       ret = HPAGE_PMD_NR;
+       set_pmd_at(mm, addr, pmd, entry);
+       BUG_ON(vma_is_anonymous(vma) && !preserve_write && pmd_write(entry));
+unlock:
+       spin_unlock(ptl);
        return ret;
 }
 
-- 
2.11.0