Merge branch 'akpm' (Andrew's patch-bomb)

Merge the rest of Andrew's patches for -rc1:
 "A bunch of fixes and misc missed-out-on things.

  That'll do for -rc1.  I still have a batch of IPC patches which still
  have a possible bug report which I'm chasing down."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits)
  keys: use keyring_alloc() to create module signing keyring
  keys: fix unreachable code
  sendfile: allows bypassing of notifier events
  SGI-XP: handle non-fatal traps
  fat: fix incorrect function comment
  Documentation: ABI: remove testing/sysfs-devices-node
  proc: fix inconsistent lock state
  linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors
  memcg: don't register hotcpu notifier from ->css_alloc()
  checkpatch: warn on uapi #includes that #include <uapi/...
  revert "rtc: recycle id when unloading a rtc driver"
  mm: clean up transparent hugepage sysfs error messages
  hfsplus: add error message for the case of failure of sync fs in delayed_sync_fs() method
  hfsplus: rework processing of hfs_btree_write() returned error
  hfsplus: rework processing errors in hfsplus_free_extents()
  hfsplus: avoid crash on failed block map free
  kcmp: include linux/ptrace.h
  drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h>
  mm: cma: WARN if freed memory is still in use
  exec: do not leave bprm->interp on stack
  ...

5 files changed, 65 insertions, 17 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 5ad7f4f4d6f..6b807e46649 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -17,6 +17,21 @@
 #include <linux/balloon_compaction.h>
 #include "internal.h"
 
+#ifdef CONFIG_COMPACTION
+static inline void count_compact_event(enum vm_event_item item)
+{
+        count_vm_event(item);
+}
+
+static inline void count_compact_events(enum vm_event_item item, long delta)
+{
+        count_vm_events(item, delta);
+}
+#else
+#define count_compact_event(item) do { } while (0)
+#define count_compact_events(item, delta) do { } while (0)
+#endif
+
 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
 
 #define CREATE_TRACE_POINTS
@@ -303,10 +318,9 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
         if (blockpfn == end_pfn)
                 update_pageblock_skip(cc, valid_page, total_isolated, false);
 
-        count_vm_events(COMPACTFREE_SCANNED, nr_scanned);
+        count_compact_events(COMPACTFREE_SCANNED, nr_scanned);
         if (total_isolated)
-                count_vm_events(COMPACTISOLATED, total_isolated);
-
+                count_compact_events(COMPACTISOLATED, total_isolated);
         return total_isolated;
 }
 
@@ -613,9 +627,9 @@ next_pageblock:
 
         trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
 
-        count_vm_events(COMPACTMIGRATE_SCANNED, nr_scanned);
+        count_compact_events(COMPACTMIGRATE_SCANNED, nr_scanned);
         if (nr_isolated)
-                count_vm_events(COMPACTISOLATED, nr_isolated);
+                count_compact_events(COMPACTISOLATED, nr_isolated);
 
         return low_pfn;
 }
@@ -1110,7 +1124,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
         if (!order || !may_enter_fs || !may_perform_io)
                 return rc;
 
-        count_vm_event(COMPACTSTALL);
+        count_compact_event(COMPACTSTALL);
 
 #ifdef CONFIG_CMA
         if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 32754eece63..9e894edc781 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -574,19 +574,19 @@ static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj)
 
         *hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
         if (unlikely(!*hugepage_kobj)) {
-                printk(KERN_ERR "hugepage: failed kobject create\n");
+                printk(KERN_ERR "hugepage: failed to create transparent hugepage kobject\n");
                 return -ENOMEM;
         }
 
         err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group);
         if (err) {
-                printk(KERN_ERR "hugepage: failed register hugeage group\n");
+                printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
                 goto delete_obj;
         }
 
         err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group);
         if (err) {
-                printk(KERN_ERR "hugepage: failed register hugeage group\n");
+                printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
                 goto remove_hp_group;
         }
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f3009b4bae5..09255ec8159 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6090,7 +6090,6 @@ mem_cgroup_css_alloc(struct cgroup *cont)
                                                 &per_cpu(memcg_stock, cpu);
                         INIT_WORK(&stock->work, drain_local_stock);
                 }
-                hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
         } else {
                 parent = mem_cgroup_from_cont(cont->parent);
                 memcg->use_hierarchy = parent->use_hierarchy;
@@ -6756,6 +6755,19 @@ struct cgroup_subsys mem_cgroup_subsys = {
         .use_id = 1,
 };
 
+/*
+ * The rest of init is performed during ->css_alloc() for root css which
+ * happens before initcalls.  hotcpu_notifier() can't be done together as
+ * it would introduce circular locking by adding cgroup_lock -> cpu hotplug
+ * dependency.  Do it from a subsys_initcall().
+ */
+static int __init mem_cgroup_init(void)
+{
+        hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
+        return 0;
+}
+subsys_initcall(mem_cgroup_init);
+
 #ifdef CONFIG_MEMCG_SWAP
 static int __init enable_swap_account(char *s)
 {
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 6f427122449..0713bfbf095 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -201,6 +201,18 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
                      zone_reclaimable_pages(z) - z->dirty_balance_reserve;
         }
         /*
+         * Unreclaimable memory (kernel memory or anonymous memory
+         * without swap) can bring down the dirtyable pages below
+         * the zone's dirty balance reserve and the above calculation
+         * will underflow.  However we still want to add in nodes
+         * which are below threshold (negative values) to get a more
+         * accurate calculation but make sure that the total never
+         * underflows.
+         */
+        if ((long)x < 0)
+                x = 0;
+
+        /*
          * Make sure that the number of highmem pages is never larger
          * than the number of the total dirtyable memory. This can only
          * occur in very strange VM situations but we want to make sure
@@ -222,8 +234,8 @@ static unsigned long global_dirtyable_memory(void)
 {
         unsigned long x;
 
-        x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages() -
-            dirty_balance_reserve;
+        x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
+        x -= min(x, dirty_balance_reserve);
 
         if (!vm_highmem_is_dirtyable)
                 x -= highmem_dirtyable_memory(x);
@@ -290,9 +302,12 @@ static unsigned long zone_dirtyable_memory(struct zone *zone)
          * highmem zone can hold its share of dirty pages, so we don't
          * care about vm_highmem_is_dirtyable here.
          */
-        return zone_page_state(zone, NR_FREE_PAGES) +
-               zone_reclaimable_pages(zone) -
-               zone->dirty_balance_reserve;
+        unsigned long nr_pages = zone_page_state(zone, NR_FREE_PAGES) +
+                zone_reclaimable_pages(zone);
+
+        /* don't allow this to underflow */
+        nr_pages -= min(nr_pages, zone->dirty_balance_reserve);
+        return nr_pages;
 }
 
 /**
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2ad2ad168ef..4ba5e37127f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5978,8 +5978,15 @@ done:
 
 void free_contig_range(unsigned long pfn, unsigned nr_pages)
 {
-        for (; nr_pages--; ++pfn)
-                __free_page(pfn_to_page(pfn));
+        unsigned int count = 0;
+
+        for (; nr_pages--; pfn++) {
+                struct page *page = pfn_to_page(pfn);
+
+                count += page_count(page) != 1;
+                __free_page(page);
+        }
+        WARN(count != 0, "%d pages are still in use!\n", count);
 }
 #endif