thp: change pmd_trans_huge_lock() interface to return ptl

[mirror_ubuntu-artful-kernel.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8ad580273521046904ec13478e7b897839d955d7..2d1ffe9d0e2632295319f562a452eecd5e4fcd49 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1560,7 +1560,8 @@ int madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
        struct mm_struct *mm = tlb->mm;
        int ret = 0;
 
-       if (!pmd_trans_huge_lock(pmd, vma, &ptl))
+       ptl = pmd_trans_huge_lock(pmd, vma);
+       if (!ptl)
                goto out_unlocked;
 
        orig_pmd = *pmd;
@@ -1627,7 +1628,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
        pmd_t orig_pmd;
        spinlock_t *ptl;
 
-       if (!__pmd_trans_huge_lock(pmd, vma, &ptl))
+       ptl = __pmd_trans_huge_lock(pmd, vma);
+       if (!ptl)
                return 0;
        /*
         * For architectures like ppc64 we look at deposited pgtable
@@ -1690,7 +1692,8 @@ bool move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
         * We don't have to worry about the ordering of src and dst
         * ptlocks because exclusive mmap_sem prevents deadlock.
         */
-       if (__pmd_trans_huge_lock(old_pmd, vma, &old_ptl)) {
+       old_ptl = __pmd_trans_huge_lock(old_pmd, vma);
+       if (old_ptl) {
                new_ptl = pmd_lockptr(mm, new_pmd);
                if (new_ptl != old_ptl)
                        spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
@@ -1724,7 +1727,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
        spinlock_t *ptl;
        int ret = 0;
 
-       if (__pmd_trans_huge_lock(pmd, vma, &ptl)) {
+       ptl = __pmd_trans_huge_lock(pmd, vma);
+       if (ptl) {
                pmd_t entry;
                bool preserve_write = prot_numa && pmd_write(*pmd);
                ret = 1;
@@ -1760,14 +1764,14 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  * Note that if it returns true, this routine returns without unlocking page
  * table lock. So callers must unlock it.
  */
-bool __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
-               spinlock_t **ptl)
+spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
 {
-       *ptl = pmd_lock(vma->vm_mm, pmd);
+       spinlock_t *ptl;
+       ptl = pmd_lock(vma->vm_mm, pmd);
        if (likely(pmd_trans_huge(*pmd) || pmd_devmap(*pmd)))
-               return true;
-       spin_unlock(*ptl);
-       return false;
+               return ptl;
+       spin_unlock(ptl);
+       return NULL;
 }
 
 #define VM_NO_THP (VM_SPECIAL | VM_HUGETLB | VM_SHARED | VM_MAYSHARE)