clear_refs: introduce private struct for mm_walk

In the next patch the clear-refs-type will be required in
clear_refs_pte_range funciton, so prepare the walk->private to carry
this info.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index dad0809..ef6f6c6 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -695,10 +695,15 @@ enum clear_refs_types {
        CLEAR_REFS_LAST,
 };
 
+struct clear_refs_private {
+       struct vm_area_struct *vma;
+};
+
 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
                                unsigned long end, struct mm_walk *walk)
 {
-       struct vm_area_struct *vma = walk->private;
+       struct clear_refs_private *cp = walk->private;
+       struct vm_area_struct *vma = cp->vma;
        pte_t *pte, ptent;
        spinlock_t *ptl;
        struct page *page;
@@ -753,13 +758,16 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                return -ESRCH;
        mm = get_task_mm(task);
        if (mm) {
+               struct clear_refs_private cp = {
+               };
                struct mm_walk clear_refs_walk = {
                        .pmd_entry = clear_refs_pte_range,
                        .mm = mm,
+                       .private = &cp,
                };
                down_read(&mm->mmap_sem);
                for (vma = mm->mmap; vma; vma = vma->vm_next) {
-                       clear_refs_walk.private = vma;
+                       cp.vma = vma;
                        if (is_vm_hugetlb_page(vma))
                                continue;
                        /*