Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "VM:
   - z3fold fixes and enhancements by Henry Burns and Vitaly Wool

   - more accurate reclaimed slab caches calculations by Yafang Shao

   - fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by
     Christoph Hellwig

   - !CONFIG_MMU fixes by Christoph Hellwig

   - new novmcoredd parameter to omit device dumps from vmcore, by
     Kairui Song

   - new test_meminit module for testing heap and pagealloc
     initialization, by Alexander Potapenko

   - ioremap improvements for huge mappings, by Anshuman Khandual

   - generalize kprobe page fault handling, by Anshuman Khandual

   - device-dax hotplug fixes and improvements, by Pavel Tatashin

   - enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V

   - add pte_devmap() support for arm64, by Robin Murphy

   - unify locked_vm accounting with a helper, by Daniel Jordan

   - several misc fixes

  core/lib:
   - new typeof_member() macro including some users, by Alexey Dobriyan

   - make BIT() and GENMASK() available in asm, by Masahiro Yamada

   - changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better
     code generation, by Alexey Dobriyan

   - rbtree code size optimizations, by Michel Lespinasse

   - convert struct pid count to refcount_t, by Joel Fernandes

  get_maintainer.pl:
   - add --no-moderated switch to skip moderated ML's, by Joe Perches

  misc:
   - ptrace PTRACE_GET_SYSCALL_INFO interface

   - coda updates

   - gdb scripts, various"

[ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ]

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits)
  fs/select.c: use struct_size() in kmalloc()
  mm: add account_locked_vm utility function
  arm64: mm: implement pte_devmap support
  mm: introduce ARCH_HAS_PTE_DEVMAP
  mm: clean up is_device_*_page() definitions
  mm/mmap: move common defines to mman-common.h
  mm: move MAP_SYNC to asm-generic/mman-common.h
  device-dax: "Hotremove" persistent memory that is used like normal RAM
  mm/hotplug: make remove_memory() interface usable
  device-dax: fix memory and resource leak if hotplug fails
  include/linux/lz4.h: fix spelling and copy-paste errors in documentation
  ipc/mqueue.c: only perform resource calculation if user valid
  include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures
  scripts/gdb: add helpers to find and list devices
  scripts/gdb: add lx-genpd-summary command
  drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
  kernel/pid.c: convert struct pid count to refcount_t
  drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
  select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining()
  select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR
  ...

1 files changed, 19 insertions, 10 deletions

diff --git a/mm/z3fold.c b/mm/z3fold.c
index dfcd69d08c1e..6c72b18d8b9c 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -101,6 +101,7 @@ struct z3fold_buddy_slots {
  * @refcount:           reference count for the z3fold page
  * @work:               work_struct for page layout optimization
  * @slots:              pointer to the structure holding buddy slots
+ * @pool:               pointer to the containing pool
  * @cpu:                CPU which this page "belongs" to
  * @first_chunks:       the size of the first buddy in chunks, 0 if free
  * @middle_chunks:      the size of the middle buddy in chunks, 0 if free
@@ -114,6 +115,7 @@ struct z3fold_header {
         struct kref refcount;
         struct work_struct work;
         struct z3fold_buddy_slots *slots;
+        struct z3fold_pool *pool;
         short cpu;
         unsigned short first_chunks;
         unsigned short middle_chunks;
@@ -193,8 +195,10 @@ static void compact_page_work(struct work_struct *w);
 static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
                                                         gfp_t gfp)
 {
-        struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle,
-                                                            gfp);
+        struct z3fold_buddy_slots *slots;
+
+        slots = kmem_cache_alloc(pool->c_handle,
+                                 (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE)));
 
         if (slots) {
                 memset(slots->slot, 0, sizeof(slots->slot));
@@ -320,6 +324,7 @@ static struct z3fold_header *init_z3fold_page(struct page *page,
         zhdr->start_middle = 0;
         zhdr->cpu = -1;
         zhdr->slots = slots;
+        zhdr->pool = pool;
         INIT_LIST_HEAD(&zhdr->buddy);
         INIT_WORK(&zhdr->work, compact_page_work);
         return zhdr;
@@ -426,7 +431,7 @@ static enum buddy handle_to_buddy(unsigned long handle)
 
 static inline struct z3fold_pool *zhdr_to_pool(struct z3fold_header *zhdr)
 {
-        return slots_to_pool(zhdr->slots);
+        return zhdr->pool;
 }
 
 static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked)
@@ -850,7 +855,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
         enum buddy bud;
         bool can_sleep = gfpflags_allow_blocking(gfp);
 
-        if (!size || (gfp & __GFP_HIGHMEM))
+        if (!size)
                 return -EINVAL;
 
         if (size > PAGE_SIZE)
@@ -1345,24 +1350,29 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
         zhdr = page_address(page);
         pool = zhdr_to_pool(zhdr);
 
-        if (!trylock_page(page))
-                return -EAGAIN;
-
         if (!z3fold_page_trylock(zhdr)) {
-                unlock_page(page);
                 return -EAGAIN;
         }
         if (zhdr->mapped_count != 0) {
                 z3fold_page_unlock(zhdr);
-                unlock_page(page);
                 return -EBUSY;
         }
+        if (work_pending(&zhdr->work)) {
+                z3fold_page_unlock(zhdr);
+                return -EAGAIN;
+        }
         new_zhdr = page_address(newpage);
         memcpy(new_zhdr, zhdr, PAGE_SIZE);
         newpage->private = page->private;
         page->private = 0;
         z3fold_page_unlock(zhdr);
         spin_lock_init(&new_zhdr->page_lock);
+        INIT_WORK(&new_zhdr->work, compact_page_work);
+        /*
+         * z3fold_page_isolate() ensures that new_zhdr->buddy is empty,
+         * so we only have to reinitialize it.
+         */
+        INIT_LIST_HEAD(&new_zhdr->buddy);
         new_mapping = page_mapping(page);
         __ClearPageMovable(page);
         ClearPagePrivate(page);
@@ -1386,7 +1396,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
         queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work);
 
         page_mapcount_reset(page);
-        unlock_page(page);
         put_page(page);
         return 0;
 }