Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6

* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (34 commits)
  HWPOISON: Remove stray phrase in a comment
  HWPOISON: Try to allocate migration page on the same node
  HWPOISON: Don't do early filtering if filter is disabled
  HWPOISON: Add a madvise() injector for soft page offlining
  HWPOISON: Add soft page offline support
  HWPOISON: Undefine short-hand macros after use to avoid namespace conflict
  HWPOISON: Use new shake_page in memory_failure
  HWPOISON: Use correct name for MADV_HWPOISON in documentation
  HWPOISON: mention HWPoison in Kconfig entry
  HWPOISON: Use get_user_page_fast in hwpoison madvise
  HWPOISON: add an interface to switch off/on all the page filters
  HWPOISON: add memory cgroup filter
  memcg: add accessor to mem_cgroup.css
  memcg: rename and export try_get_mem_cgroup_from_page()
  HWPOISON: add page flags filter
  mm: export stable page flags
  HWPOISON: limit hwpoison injector to known page types
  HWPOISON: add fs/device filters
  HWPOISON: return 0 to indicate success reliably
  HWPOISON: make semantics of IGNORED/DELAYED clear
  ...

1 files changed, 9 insertions, 7 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 878808c4fcbe..488b644e0e8e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -283,6 +283,11 @@ mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
         return &mem->info.nodeinfo[nid]->zoneinfo[zid];
 }
 
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+{
+        return &mem->css;
+}
+
 static struct mem_cgroup_per_zone *
 page_cgroup_zoneinfo(struct page_cgroup *pc)
 {
@@ -1536,25 +1541,22 @@ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
         return container_of(css, struct mem_cgroup, css);
 }
 
-static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
+struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *mem = NULL;
         struct page_cgroup *pc;
         unsigned short id;
         swp_entry_t ent;
 
         VM_BUG_ON(!PageLocked(page));
 
-        if (!PageSwapCache(page))
-                return NULL;
-
         pc = lookup_page_cgroup(page);
         lock_page_cgroup(pc);
         if (PageCgroupUsed(pc)) {
                 mem = pc->mem_cgroup;
                 if (mem && !css_tryget(&mem->css))
                         mem = NULL;
-        } else {
+        } else if (PageSwapCache(page)) {
                 ent.val = page_private(page);
                 id = lookup_swap_cgroup(ent);
                 rcu_read_lock();
@@ -1874,7 +1876,7 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
          */
         if (!PageSwapCache(page))
                 goto charge_cur_mm;
-        mem = try_get_mem_cgroup_from_swapcache(page);
+        mem = try_get_mem_cgroup_from_page(page);
         if (!mem)
                 goto charge_cur_mm;
         *ptr = mem;