Merge branch 'akpm' (incoming fixes from Andrew)

Merge misc fixes from Andrew Morton:
 "The audit fixes have been floating around for a while - Al and Eric
  aren't responding to either myself or Kees so I asked Kees to
  re-review them and here they are."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  lib/rbtree.c: avoid the use of non-static __always_inline
  MAINTAINERS: Omar had moved
  mm: compaction: partially revert capture of suitable high-order page
  linux/audit.h: move ptrace.h include to kernel header
  kernel/audit.c: avoid negative sleep durations
  audit: catch possible NULL audit buffers
  audit: create explicit AUDIT_SECCOMP event type
  MAINTAINERS: fix a status pattern
  MAINTAINERS: fix arch/arm/plat-omap/include/plat/omap_hwmod.h
  mm: thp: acquire the anon_vma rwsem for write during split
  mm: mmap: annotate vm_lock_anon_vma locking properly for lockdep
  lockdep, rwsem: provide down_write_nest_lock()
  arch/mn10300/Kconfig: select CONFIG_GENERIC_ATOMIC64
  mm: bootmem: fix free_all_bootmem_core() with odd bitmap alignment
  mm: use aligned zone start for pfn_to_bitidx calculation
  fs/exec.c: work around icc miscompilation
  mm: compaction: fix echo 1 > compact_memory return error issue
  mm: memblock: fix wrong memmove size in memblock_merge_regions()
  drivers/video/ssd1307fb.c: fix bit order bug in the byte translation function
  mm: migrate: check page_count of THP before migrating
  ...

1 files changed, 13 insertions, 1 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 3b676b0c5c3e..c38778610aa8 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1679,9 +1679,21 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 	page_xchg_last_nid(new_page, page_last_nid(page));
 
 	isolated = numamigrate_isolate_page(pgdat, page);
-	if (!isolated) {
+
+	/*
+	 * Failing to isolate or a GUP pin prevents migration. The expected
+	 * page count is 2. 1 for anonymous pages without a mapping and 1
+	 * for the callers pin. If the page was isolated, the page will
+	 * need to be put back on the LRU.
+	 */
+	if (!isolated || page_count(page) != 2) {
 		count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
 		put_page(new_page);
+		if (isolated) {
+			putback_lru_page(page);
+			isolated = 0;
+			goto out;
+		}
 		goto out_keep_locked;
 	}