Re: [PATCH -mm v8 2/7] hwpoison: use page_cgroup_ino for filtering by memcg

---
 mm/hwpoison-inject.c |  5 +----
 mm/memory-failure.c  | 16 ++--------------
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index bf73ac17dad4..5015679014c1 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c

@@ -45,12 +45,9 @@ static int hwpoison_inject(void *data, u64 val)
        /*
         * do a racy check with elevated page count, to make sure PG_hwpoison
         * will only be set for the targeted owner (or on a free page).
-        * We temporarily take page lock for try_get_mem_cgroup_from_page().
         * memory_failure() will redo the check reliably inside page lock.
         */
-       lock_page(hpage);
        err = hwpoison_filter(hpage);
-       unlock_page(hpage);
        if (err)
                goto put_out;

@@ -126,7 +123,7 @@ static int pfn_inject_init(void)
        if (!dentry)
                goto fail;

-#ifdef CONFIG_MEMCG_SWAP
+#ifdef CONFIG_MEMCG
        dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
                                    hwpoison_dir, &hwpoison_filter_memcg);
        if (!dentry)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 1cf7f2988422..97005396a507 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c

@@ -130,27 +130,15 @@ static int hwpoison_filter_flags(struct page *p)
  * can only guarantee that the page either belongs to the memcg tasks, or is
  * a freed page.
  */
-#ifdef CONFIG_MEMCG_SWAP
+#ifdef CONFIG_MEMCG
 u64 hwpoison_filter_memcg;
 EXPORT_SYMBOL_GPL(hwpoison_filter_memcg);
 static int hwpoison_filter_task(struct page *p)
 {
-       struct mem_cgroup *mem;
-       struct cgroup_subsys_state *css;
-       unsigned long ino;
-
        if (!hwpoison_filter_memcg)
                return 0;

-       mem = try_get_mem_cgroup_from_page(p);
-       if (!mem)
-               return -EINVAL;
-
-       css = mem_cgroup_css(mem);
-       ino = cgroup_ino(css->cgroup);
-       css_put(css);
-
-       if (ino != hwpoison_filter_memcg)
+       if (page_cgroup_ino(p) != hwpoison_filter_memcg)
                return -EINVAL;

        return 0;
--

2.1.4