Merge branch 'akpm' (second patch-bomb from Andrew)

Merge second patchbomb from Andrew Morton:
 - the rest of MM
 - misc fs fixes
 - add execveat() syscall
 - new ratelimit feature for fault-injection
 - decompressor updates
 - ipc/ updates
 - fallocate feature creep
 - fsnotify cleanups
 - a few other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (99 commits)
  cgroups: Documentation: fix trivial typos and wrong paragraph numberings
  parisc: percpu: update comments referring to __get_cpu_var
  percpu: update local_ops.txt to reflect this_cpu operations
  percpu: remove __get_cpu_var and __raw_get_cpu_var macros
  fsnotify: remove destroy_list from fsnotify_mark
  fsnotify: unify inode and mount marks handling
  fallocate: create FAN_MODIFY and IN_MODIFY events
  mm/cma: make kmemleak ignore CMA regions
  slub: fix cpuset check in get_any_partial
  slab: fix cpuset check in fallback_alloc
  shmdt: use i_size_read() instead of ->i_size
  ipc/shm.c: fix overly aggressive shmdt() when calls span multiple segments
  ipc/msg: increase MSGMNI, remove scaling
  ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
  ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
  lib/decompress.c: consistency of compress formats for kernel image
  decompress_bunzip2: off by one in get_next_block()
  usr/Kconfig: make initrd compression algorithm selection not expert
  fault-inject: add ratelimit option
  ratelimit: add initialization macro
  ...

1 files changed, 18 insertions, 10 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 01439953abf5..253474c22239 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -746,7 +746,7 @@ static int fallback_migrate_page(struct address_space *mapping,
  *  MIGRATEPAGE_SUCCESS - success
  */
 static int move_to_new_page(struct page *newpage, struct page *page,
-                                int remap_swapcache, enum migrate_mode mode)
+                                int page_was_mapped, enum migrate_mode mode)
 {
         struct address_space *mapping;
         int rc;
@@ -784,7 +784,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
                 newpage->mapping = NULL;
         } else {
                 mem_cgroup_migrate(page, newpage, false);
-                if (remap_swapcache)
+                if (page_was_mapped)
                         remove_migration_ptes(page, newpage);
                 page->mapping = NULL;
         }
@@ -798,7 +798,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
                                 int force, enum migrate_mode mode)
 {
         int rc = -EAGAIN;
-        int remap_swapcache = 1;
+        int page_was_mapped = 0;
         struct anon_vma *anon_vma = NULL;
 
         if (!trylock_page(page)) {
@@ -870,7 +870,6 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
                          * migrated but are not remapped when migration
                          * completes
                          */
-                        remap_swapcache = 0;
                 } else {
                         goto out_unlock;
                 }
@@ -910,13 +909,17 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
         }
 
         /* Establish migration ptes or remove ptes */
-        try_to_unmap(page, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+        if (page_mapped(page)) {
+                try_to_unmap(page,
+                        TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+                page_was_mapped = 1;
+        }
 
 skip_unmap:
         if (!page_mapped(page))
-                rc = move_to_new_page(newpage, page, remap_swapcache, mode);
+                rc = move_to_new_page(newpage, page, page_was_mapped, mode);
 
-        if (rc && remap_swapcache)
+        if (rc && page_was_mapped)
                 remove_migration_ptes(page, page);
 
         /* Drop an anon_vma reference if we took one */
@@ -1017,6 +1020,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 {
         int rc = 0;
         int *result = NULL;
+        int page_was_mapped = 0;
         struct page *new_hpage;
         struct anon_vma *anon_vma = NULL;
 
@@ -1047,12 +1051,16 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
         if (PageAnon(hpage))
                 anon_vma = page_get_anon_vma(hpage);
 
-        try_to_unmap(hpage, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+        if (page_mapped(hpage)) {
+                try_to_unmap(hpage,
+                        TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+                page_was_mapped = 1;
+        }
 
         if (!page_mapped(hpage))
-                rc = move_to_new_page(new_hpage, hpage, 1, mode);
+                rc = move_to_new_page(new_hpage, hpage, page_was_mapped, mode);
 
-        if (rc != MIGRATEPAGE_SUCCESS)
+        if (rc != MIGRATEPAGE_SUCCESS && page_was_mapped)
                 remove_migration_ptes(hpage, hpage);
 
         if (anon_vma)