mm: put_and_wait_on_page_locked() while page is migrated

[sfrench/cifs-2.6.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index f7e4bfdc13b780137d08fa522b070e7192056f24..acda06f99754995b1dcf54b7c7760cdd5612b214 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -327,16 +327,13 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
 
        /*
         * Once page cache replacement of page migration started, page_count
-        * *must* be zero. And, we don't want to call wait_on_page_locked()
-        * against a page without get_page().
-        * So, we use get_page_unless_zero(), here. Even failed, page fault
-        * will occur again.
+        * is zero; but we must not call put_and_wait_on_page_locked() without
+        * a ref. Use get_page_unless_zero(), and just fault again if it fails.
         */
        if (!get_page_unless_zero(page))
                goto out;
        pte_unmap_unlock(ptep, ptl);
-       wait_on_page_locked(page);
-       put_page(page);
+       put_and_wait_on_page_locked(page);
        return;
 out:
        pte_unmap_unlock(ptep, ptl);
@@ -370,8 +367,7 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
        if (!get_page_unless_zero(page))
                goto unlock;
        spin_unlock(ptl);
-       wait_on_page_locked(page);
-       put_page(page);
+       put_and_wait_on_page_locked(page);
        return;
 unlock:
        spin_unlock(ptl);