Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "190 patches.

  Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
  vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
  migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
  zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
  core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
  signals, exec, kcov, selftests, compress/decompress, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  ipc/util.c: use binary search for max_idx
  ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
  ipc: use kmalloc for msg_queue and shmid_kernel
  ipc sem: use kvmalloc for sem_undo allocation
  lib/decompressors: remove set but not used variabled 'level'
  selftests/vm/pkeys: exercise x86 XSAVE init state
  selftests/vm/pkeys: refill shadow register after implicit kernel write
  selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
  selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
  kcov: add __no_sanitize_coverage to fix noinstr for all architectures
  exec: remove checks in __register_bimfmt()
  x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
  hfsplus: report create_date to kstat.btime
  hfsplus: remove unnecessary oom message
  nilfs2: remove redundant continue statement in a while-loop
  kprobes: remove duplicated strong free_insn_page in x86 and s390
  init: print out unknown kernel parameters
  checkpatch: do not complain about positive return values starting with EPOLL
  checkpatch: improve the indented label test
  checkpatch: scripts/spdxcheck.py now requires python3
  ...

45 files changed, 2919 insertions, 1411 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index ded98fb859ab..a02498c0e13d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -96,6 +96,9 @@ config HAVE_FAST_GUP
 	depends on MMU
 	bool
 
+config HOLES_IN_ZONE
+	bool
+
 # Don't discard allocated memory used to track "memory" and "reserved" memblocks
 # after early boot, so it can still be used to test for validity of memory.
 # Also, memblocks are updated with memory hot(un)plug.
@@ -671,6 +674,7 @@ config ZPOOL
 
 config ZBUD
 	tristate "Low (Up to 2x) density storage for compressed pages"
+	depends on ZPOOL
 	help
 	  A special purpose allocator for storing compressed pages.
 	  It is designed to store up to two compressed pages per physical
@@ -757,6 +761,18 @@ config ARCH_HAS_CACHE_LINE_SIZE
 config ARCH_HAS_PTE_DEVMAP
 	bool
 
+config ARCH_HAS_ZONE_DMA_SET
+	bool
+
+config ZONE_DMA
+	bool "Support DMA zone" if ARCH_HAS_ZONE_DMA_SET
+	default y if ARM64 || X86
+
+config ZONE_DMA32
+	bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET
+	depends on !X86_32
+	default y if ARM64
+
 config ZONE_DEVICE
 	bool "Device memory (pmem, HMM, etc...) hotplug support"
 	depends on MEMORY_HOTPLUG
diff --git a/mm/Makefile b/mm/Makefile
index bf71e295e9f6..74b47c354682 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_FRONTSWAP)	+= frontswap.o
 obj-$(CONFIG_ZSWAP)	+= zswap.o
 obj-$(CONFIG_HAS_DMA)	+= dmapool.o
 obj-$(CONFIG_HUGETLBFS)	+= hugetlb.o
+obj-$(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP)	+= hugetlb_vmemmap.o
 obj-$(CONFIG_NUMA) 	+= mempolicy.o
 obj-$(CONFIG_SPARSEMEM)	+= sparse.o
 obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
@@ -125,3 +126,4 @@ obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o
 obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
 obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o
 obj-$(CONFIG_IO_MAPPING) += io-mapping.o
+obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o
diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c
new file mode 100644
index 000000000000..5b152dba7344
--- /dev/null
+++ b/mm/bootmem_info.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Bootmem core functions.
+ *
+ * Copyright (c) 2020, Bytedance.
+ *
+ *     Author: Muchun Song <songmuchun@bytedance.com>
+ *
+ */
+#include <linux/mm.h>
+#include <linux/compiler.h>
+#include <linux/memblock.h>
+#include <linux/bootmem_info.h>
+#include <linux/memory_hotplug.h>
+
+void get_page_bootmem(unsigned long info, struct page *page, unsigned long type)
+{
+	page->freelist = (void *)type;
+	SetPagePrivate(page);
+	set_page_private(page, info);
+	page_ref_inc(page);
+}
+
+void put_page_bootmem(struct page *page)
+{
+	unsigned long type;
+
+	type = (unsigned long) page->freelist;
+	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+	       type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
+
+	if (page_ref_dec_return(page) == 1) {
+		page->freelist = NULL;
+		ClearPagePrivate(page);
+		set_page_private(page, 0);
+		INIT_LIST_HEAD(&page->lru);
+		free_reserved_page(page);
+	}
+}
+
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+static void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+	unsigned long mapsize, section_nr, i;
+	struct mem_section *ms;
+	struct page *page, *memmap;
+	struct mem_section_usage *usage;
+
+	section_nr = pfn_to_section_nr(start_pfn);
+	ms = __nr_to_section(section_nr);
+
+	/* Get section's memmap address */
+	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+	/*
+	 * Get page for the memmap's phys address
+	 * XXX: need more consideration for sparse_vmemmap...
+	 */
+	page = virt_to_page(memmap);
+	mapsize = sizeof(struct page) * PAGES_PER_SECTION;
+	mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
+
+	/* remember memmap's page */
+	for (i = 0; i < mapsize; i++, page++)
+		get_page_bootmem(section_nr, page, SECTION_INFO);
+
+	usage = ms->usage;
+	page = virt_to_page(usage);
+
+	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
+
+	for (i = 0; i < mapsize; i++, page++)
+		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
+
+}
+#else /* CONFIG_SPARSEMEM_VMEMMAP */
+static void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+	unsigned long mapsize, section_nr, i;
+	struct mem_section *ms;
+	struct page *page, *memmap;
+	struct mem_section_usage *usage;
+
+	section_nr = pfn_to_section_nr(start_pfn);
+	ms = __nr_to_section(section_nr);
+
+	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+	register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
+
+	usage = ms->usage;
+	page = virt_to_page(usage);
+
+	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
+
+	for (i = 0; i < mapsize; i++, page++)
+		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+	unsigned long i, pfn, end_pfn, nr_pages;
+	int node = pgdat->node_id;
+	struct page *page;
+
+	nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
+	page = virt_to_page(pgdat);
+
+	for (i = 0; i < nr_pages; i++, page++)
+		get_page_bootmem(node, page, NODE_INFO);
+
+	pfn = pgdat->node_start_pfn;
+	end_pfn = pgdat_end_pfn(pgdat);
+
+	/* register section info */
+	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+		/*
+		 * Some platforms can assign the same pfn to multiple nodes - on
+		 * node0 as well as nodeN.  To avoid registering a pfn against
+		 * multiple nodes we check that this pfn does not already
+		 * reside in some other nodes.
+		 */
+		if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
+			register_page_bootmem_info_section(pfn);
+	}
+}
diff --git a/mm/compaction.c b/mm/compaction.c
index 3a509fbf2bea..621508e0ecd5 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1297,8 +1297,7 @@ move_freelist_head(struct list_head *freelist, struct page *freepage)
 
 	if (!list_is_last(freelist, &freepage->lru)) {
 		list_cut_before(&sublist, freelist, &freepage->lru);
-		if (!list_empty(&sublist))
-			list_splice_tail(&sublist, freelist);
+		list_splice_tail(&sublist, freelist);
 	}
 }
 
@@ -1315,8 +1314,7 @@ move_freelist_tail(struct list_head *freelist, struct page *freepage)
 
 	if (!list_is_first(freelist, &freepage->lru)) {
 		list_cut_position(&sublist, freelist, &freepage->lru);
-		if (!list_empty(&sublist))
-			list_splice_tail(&sublist, freelist);
+		list_splice_tail(&sublist, freelist);
 	}
 }
 
@@ -1380,7 +1378,7 @@ static int next_search_order(struct compact_control *cc, int order)
 static unsigned long
 fast_isolate_freepages(struct compact_control *cc)
 {
-	unsigned int limit = min(1U, freelist_scan_limit(cc) >> 1);
+	unsigned int limit = max(1U, freelist_scan_limit(cc) >> 1);
 	unsigned int nr_scanned = 0;
 	unsigned long low_pfn, min_pfn, highest = 0;
 	unsigned long nr_isolated = 0;
@@ -1492,11 +1490,11 @@ fast_isolate_freepages(struct compact_control *cc)
 		spin_unlock_irqrestore(&cc->zone->lock, flags);
 
 		/*
-		 * Smaller scan on next order so the total scan ig related
+		 * Smaller scan on next order so the total scan is related
 		 * to freelist_scan_limit.
 		 */
 		if (order_scanned >= limit)
-			limit = min(1U, limit >> 1);
+			limit = max(1U, limit >> 1);
 	}
 
 	if (!page) {
@@ -2722,9 +2720,9 @@ int sysctl_compaction_handler(struct ctl_table *table, int write,
 }
 
 #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
-static ssize_t sysfs_compact_node(struct device *dev,
-			struct device_attribute *attr,
-			const char *buf, size_t count)
+static ssize_t compact_store(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t count)
 {
 	int nid = dev->id;
 
@@ -2737,7 +2735,7 @@ static ssize_t sysfs_compact_node(struct device *dev,
 
 	return count;
 }
-static DEVICE_ATTR(compact, 0200, NULL, sysfs_compact_node);
+static DEVICE_ATTR_WO(compact);
 
 int compaction_register_node(struct node *node)
 {
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 92bfc37300df..1c922691aa61 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -91,7 +91,7 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
 				      unsigned long pfn, unsigned long vaddr,
 				      pgprot_t prot)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte;
 
 	/*
 	 * Architectures optimize set_pte_at by avoiding TLB flush.
@@ -248,29 +248,6 @@ static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
 	WARN_ON(!pmd_leaf(pmd));
 }
 
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
-{
-	pmd_t pmd;
-
-	if (!arch_vmap_pmd_supported(prot))
-		return;
-
-	pr_debug("Validating PMD huge\n");
-	/*
-	 * X86 defined pmd_set_huge() verifies that the given
-	 * PMD is not a populated non-leaf entry.
-	 */
-	WRITE_ONCE(*pmdp, __pmd(0));
-	WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
-	WARN_ON(!pmd_clear_huge(pmdp));
-	pmd = READ_ONCE(*pmdp);
-	WARN_ON(!pmd_none(pmd));
-}
-#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
-static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
-#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
-
 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
 {
 	pmd_t pmd;
@@ -395,30 +372,6 @@ static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
 	pud = pud_mkhuge(pud);
 	WARN_ON(!pud_leaf(pud));
 }
-
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
-{
-	pud_t pud;
-
-	if (!arch_vmap_pud_supported(prot))
-		return;
-
-	pr_debug("Validating PUD huge\n");
-	/*
-	 * X86 defined pud_set_huge() verifies that the given
-	 * PUD is not a populated non-leaf entry.
-	 */
-	WRITE_ONCE(*pudp, __pud(0));
-	WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
-	WARN_ON(!pud_clear_huge(pudp));
-	pud = READ_ONCE(*pudp);
-	WARN_ON(!pud_none(pud));
-}
-#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
-#endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
-
 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
 static void __init pud_advanced_tests(struct mm_struct *mm,
@@ -428,9 +381,6 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
 {
 }
 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
-{
-}
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
@@ -449,14 +399,51 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
 }
 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
 {
+	pmd_t pmd;
+
+	if (!arch_vmap_pmd_supported(prot))
+		return;
+
+	pr_debug("Validating PMD huge\n");
+	/*
+	 * X86 defined pmd_set_huge() verifies that the given
+	 * PMD is not a populated non-leaf entry.
+	 */
+	WRITE_ONCE(*pmdp, __pmd(0));
+	WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
+	WARN_ON(!pmd_clear_huge(pmdp));
+	pmd = READ_ONCE(*pmdp);
+	WARN_ON(!pmd_none(pmd));
 }
+
 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
 {
+	pud_t pud;
+
+	if (!arch_vmap_pud_supported(prot))
+		return;
+
+	pr_debug("Validating PUD huge\n");
+	/*
+	 * X86 defined pud_set_huge() verifies that the given
+	 * PUD is not a populated non-leaf entry.
+	 */
+	WRITE_ONCE(*pudp, __pud(0));
+	WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
+	WARN_ON(!pud_clear_huge(pudp));
+	pud = READ_ONCE(*pudp);
+	WARN_ON(!pud_none(pud));
 }
-static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 
 static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
 {
@@ -791,12 +778,12 @@ static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 	WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
 	WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
 }
-#else  /* !CONFIG_ARCH_HAS_PTE_DEVMAP */
+#else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 {
 }
-#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
 {
@@ -856,17 +843,17 @@ static void __init swap_migration_tests(void)
 	 * locked, otherwise it stumbles upon a BUG_ON().
 	 */
 	__SetPageLocked(page);
-	swp = make_migration_entry(page, 1);
+	swp = make_writable_migration_entry(page_to_pfn(page));
 	WARN_ON(!is_migration_entry(swp));
-	WARN_ON(!is_write_migration_entry(swp));
+	WARN_ON(!is_writable_migration_entry(swp));
 
-	make_migration_entry_read(&swp);
+	swp = make_readable_migration_entry(swp_offset(swp));
 	WARN_ON(!is_migration_entry(swp));
-	WARN_ON(is_write_migration_entry(swp));
+	WARN_ON(is_writable_migration_entry(swp));
 
-	swp = make_migration_entry(page, 0);
+	swp = make_readable_migration_entry(page_to_pfn(page));
 	WARN_ON(!is_migration_entry(swp));
-	WARN_ON(is_write_migration_entry(swp));
+	WARN_ON(is_writable_migration_entry(swp));
 	__ClearPageLocked(page);
 	__free_page(page);
 }
diff --git a/mm/gup.c b/mm/gup.c
index 8651309f8ec3..728d996767cb 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1501,6 +1501,64 @@ long populate_vma_page_range(struct vm_area_struct *vma,
 }
 
 /*
+ * faultin_vma_page_range() - populate (prefault) page tables inside the
+ *			      given VMA range readable/writable
+ *
+ * This takes care of mlocking the pages, too, if VM_LOCKED is set.
+ *
+ * @vma: target vma
+ * @start: start address
+ * @end: end address
+ * @write: whether to prefault readable or writable
+ * @locked: whether the mmap_lock is still held
+ *
+ * Returns either number of processed pages in the vma, or a negative error
+ * code on error (see __get_user_pages()).
+ *
+ * vma->vm_mm->mmap_lock must be held. The range must be page-aligned and
+ * covered by the VMA.
+ *
+ * If @locked is NULL, it may be held for read or write and will be unperturbed.
+ *
+ * If @locked is non-NULL, it must held for read only and may be released.  If
+ * it's released, *@locked will be set to 0.
+ */
+long faultin_vma_page_range(struct vm_area_struct *vma, unsigned long start,
+			    unsigned long end, bool write, int *locked)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long nr_pages = (end - start) / PAGE_SIZE;
+	int gup_flags;
+
+	VM_BUG_ON(!PAGE_ALIGNED(start));
+	VM_BUG_ON(!PAGE_ALIGNED(end));
+	VM_BUG_ON_VMA(start < vma->vm_start, vma);
+	VM_BUG_ON_VMA(end > vma->vm_end, vma);
+	mmap_assert_locked(mm);
+
+	/*
+	 * FOLL_TOUCH: Mark page accessed and thereby young; will also mark
+	 *	       the page dirty with FOLL_WRITE -- which doesn't make a
+	 *	       difference with !FOLL_FORCE, because the page is writable
+	 *	       in the page table.
+	 * FOLL_HWPOISON: Return -EHWPOISON instead of -EFAULT when we hit
+	 *		  a poisoned page.
+	 * FOLL_POPULATE: Always populate memory with VM_LOCKONFAULT.
+	 * !FOLL_FORCE: Require proper access permissions.
+	 */
+	gup_flags = FOLL_TOUCH | FOLL_POPULATE | FOLL_MLOCK | FOLL_HWPOISON;
+	if (write)
+		gup_flags |= FOLL_WRITE;
+
+	/*
+	 * See check_vma_flags(): Will return -EFAULT on incompatible mappings
+	 * or with insufficient permissions.
+	 */
+	return __get_user_pages(mm, start, nr_pages, gup_flags,
+				NULL, NULL, locked);
+}
+
+/*
  * __mm_populate - populate and/or mlock pages within a range of address space.
  *
  * This is used to implement mlock() and the MAP_POPULATE / MAP_LOCKED mmap
diff --git a/mm/hmm.c b/mm/hmm.c
index 943cb2ba4442..fad6be2bf072 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -26,6 +26,8 @@
 #include <linux/mmu_notifier.h>
 #include <linux/memory_hotplug.h>
 
+#include "internal.h"
+
 struct hmm_vma_walk {
 	struct hmm_range	*range;
 	unsigned long		last;
@@ -214,7 +216,7 @@ static inline bool hmm_is_device_private_entry(struct hmm_range *range,
 		swp_entry_t entry)
 {
 	return is_device_private_entry(entry) &&
-		device_private_entry_to_page(entry)->pgmap->owner ==
+		pfn_swap_entry_to_page(entry)->pgmap->owner ==
 		range->dev_private_owner;
 }
 
@@ -255,10 +257,9 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
 		 */
 		if (hmm_is_device_private_entry(range, entry)) {
 			cpu_flags = HMM_PFN_VALID;
-			if (is_write_device_private_entry(entry))
+			if (is_writable_device_private_entry(entry))
 				cpu_flags |= HMM_PFN_WRITE;
-			*hmm_pfn = device_private_entry_to_pfn(entry) |
-					cpu_flags;
+			*hmm_pfn = swp_offset(entry) | cpu_flags;
 			return 0;
 		}
 
@@ -272,6 +273,9 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
 		if (!non_swap_entry(entry))
 			goto fault;
 
+		if (is_device_exclusive_entry(entry))
+			goto fault;
+
 		if (is_migration_entry(entry)) {
 			pte_unmap(ptep);
 			hmm_vma_walk->last = addr;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 6d2a0119fc58..8b731d53e9f4 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -64,7 +64,14 @@ static atomic_t huge_zero_refcount;
 struct page *huge_zero_page __read_mostly;
 unsigned long huge_zero_pfn __read_mostly = ~0UL;
 
-bool transparent_hugepage_enabled(struct vm_area_struct *vma)
+static inline bool file_thp_enabled(struct vm_area_struct *vma)
+{
+	return transhuge_vma_enabled(vma, vma->vm_flags) && vma->vm_file &&
+	       !inode_is_open_for_write(vma->vm_file->f_inode) &&
+	       (vma->vm_flags & VM_EXEC);
+}
+
+bool transparent_hugepage_active(struct vm_area_struct *vma)
 {
 	/* The addr is used to check if the vma size fits */
 	unsigned long addr = (vma->vm_end & HPAGE_PMD_MASK) - HPAGE_PMD_SIZE;
@@ -75,6 +82,8 @@ bool transparent_hugepage_enabled(struct vm_area_struct *vma)
 		return __transparent_hugepage_enabled(vma);
 	if (vma_is_shmem(vma))
 		return shmem_huge_enabled(vma);
+	if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS))
+		return file_thp_enabled(vma);
 
 	return false;
 }
@@ -1017,7 +1026,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 
 int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		  pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
-		  struct vm_area_struct *vma)
+		  struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma)
 {
 	spinlock_t *dst_ptl, *src_ptl;
 	struct page *src_page;
@@ -1026,7 +1035,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	int ret = -ENOMEM;
 
 	/* Skip if can be re-fill on fault */
-	if (!vma_is_anonymous(vma))
+	if (!vma_is_anonymous(dst_vma))
 		return 0;
 
 	pgtable = pte_alloc_one(dst_mm);
@@ -1040,29 +1049,26 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	ret = -EAGAIN;
 	pmd = *src_pmd;
 
-	/*
-	 * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA
-	 * does not have the VM_UFFD_WP, which means that the uffd
-	 * fork event is not enabled.
-	 */
-	if (!(vma->vm_flags & VM_UFFD_WP))
-		pmd = pmd_clear_uffd_wp(pmd);
-
 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
 	if (unlikely(is_swap_pmd(pmd))) {
 		swp_entry_t entry = pmd_to_swp_entry(pmd);
 
 		VM_BUG_ON(!is_pmd_migration_entry(pmd));
-		if (is_write_migration_entry(entry)) {
-			make_migration_entry_read(&entry);
+		if (is_writable_migration_entry(entry)) {
+			entry = make_readable_migration_entry(
+							swp_offset(entry));
 			pmd = swp_entry_to_pmd(entry);
 			if (pmd_swp_soft_dirty(*src_pmd))
 				pmd = pmd_swp_mksoft_dirty(pmd);
+			if (pmd_swp_uffd_wp(*src_pmd))
+				pmd = pmd_swp_mkuffd_wp(pmd);
 			set_pmd_at(src_mm, addr, src_pmd, pmd);
 		}
 		add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
 		mm_inc_nr_ptes(dst_mm);
 		pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
+		if (!userfaultfd_wp(dst_vma))
+			pmd = pmd_swp_clear_uffd_wp(pmd);
 		set_pmd_at(dst_mm, addr, dst_pmd, pmd);
 		ret = 0;
 		goto out_unlock;
@@ -1079,17 +1085,13 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	 * a page table.
 	 */
 	if (is_huge_zero_pmd(pmd)) {
-		struct page *zero_page;
 		/*
 		 * get_huge_zero_page() will never allocate a new page here,
 		 * since we already have a zero page to copy. It just takes a
 		 * reference.
 		 */
-		zero_page = mm_get_huge_zero_page(dst_mm);
-		set_huge_zero_page(pgtable, dst_mm, vma, addr, dst_pmd,
-				zero_page);
-		ret = 0;
-		goto out_unlock;
+		mm_get_huge_zero_page(dst_mm);
+		goto out_zero_page;
 	}
 
 	src_page = pmd_page(pmd);
@@ -1102,21 +1104,23 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	 * best effort that the pinned pages won't be replaced by another
 	 * random page during the coming copy-on-write.
 	 */
-	if (unlikely(page_needs_cow_for_dma(vma, src_page))) {
+	if (unlikely(page_needs_cow_for_dma(src_vma, src_page))) {
 		pte_free(dst_mm, pgtable);
 		spin_unlock(src_ptl);
 		spin_unlock(dst_ptl);
-		__split_huge_pmd(vma, src_pmd, addr, false, NULL);
+		__split_huge_pmd(src_vma, src_pmd, addr, false, NULL);
 		return -EAGAIN;
 	}
 
 	get_page(src_page);
 	page_dup_rmap(src_page, true);
 	add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
+out_zero_page:
 	mm_inc_nr_ptes(dst_mm);
 	pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
-
 	pmdp_set_wrprotect(src_mm, addr, src_pmd);
+	if (!userfaultfd_wp(dst_vma))
+		pmd = pmd_clear_uffd_wp(pmd);
 	pmd = pmd_mkold(pmd_wrprotect(pmd));
 	set_pmd_at(dst_mm, addr, dst_pmd, pmd);
 
@@ -1254,11 +1258,12 @@ unlock:
 }
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 
-void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd)
+void huge_pmd_set_accessed(struct vm_fault *vmf)
 {
 	pmd_t entry;
 	unsigned long haddr;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
+	pmd_t orig_pmd = vmf->orig_pmd;
 
 	vmf->ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd);
 	if (unlikely(!pmd_same(*vmf->pmd, orig_pmd)))
@@ -1275,11 +1280,12 @@ unlock:
 	spin_unlock(vmf->ptl);
 }
 
-vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
+vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct page *page;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
+	pmd_t orig_pmd = vmf->orig_pmd;
 
 	vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd);
 	VM_BUG_ON_VMA(!vma->anon_vma, vma);
@@ -1415,96 +1421,25 @@ out:
 }
 
 /* NUMA hinting page fault entry point for trans huge pmds */
-vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
+vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
-	struct anon_vma *anon_vma = NULL;
+	pmd_t oldpmd = vmf->orig_pmd;
+	pmd_t pmd;
 	struct page *page;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
-	int page_nid = NUMA_NO_NODE, this_nid = numa_node_id();
+	int page_nid = NUMA_NO_NODE;
 	int target_nid, last_cpupid = -1;
-	bool page_locked;
 	bool migrated = false;
-	bool was_writable;
+	bool was_writable = pmd_savedwrite(oldpmd);
 	int flags = 0;
 
 	vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
-	if (unlikely(!pmd_same(pmd, *vmf->pmd)))
-		goto out_unlock;
-
-	/*
-	 * If there are potential migrations, wait for completion and retry
-	 * without disrupting NUMA hinting information. Do not relock and
-	 * check_same as the page may no longer be mapped.
-	 */
-	if (unlikely(pmd_trans_migrating(*vmf->pmd))) {
-		page = pmd_page(*vmf->pmd);
-		if (!get_page_unless_zero(page))
-			goto out_unlock;
+	if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) {
 		spin_unlock(vmf->ptl);
-		put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE);
 		goto out;
 	}
 
-	page = pmd_page(pmd);
-	BUG_ON(is_huge_zero_page(page));
-	page_nid = page_to_nid(page);
-	last_cpupid = page_cpupid_last(page);
-	count_vm_numa_event(NUMA_HINT_FAULTS);
-	if (page_nid == this_nid) {
-		count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
-		flags |= TNF_FAULT_LOCAL;
-	}
-
-	/* See similar comment in do_numa_page for explanation */
-	if (!pmd_savedwrite(pmd))
-		flags |= TNF_NO_GROUP;
-
-	/*
-	 * Acquire the page lock to serialise THP migrations but avoid dropping
-	 * page_table_lock if at all possible
-	 */
-	page_locked = trylock_page(page);
-	target_nid = mpol_misplaced(page, vma, haddr);
-	/* Migration could have started since the pmd_trans_migrating check */
-	if (!page_locked) {
-		page_nid = NUMA_NO_NODE;
-		if (!get_page_unless_zero(page))
-			goto out_unlock;
-		spin_unlock(vmf->ptl);
-		put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE);
-		goto out;
-	} else if (target_nid == NUMA_NO_NODE) {
-		/* There are no parallel migrations and page is in the right
-		 * node. Clear the numa hinting info in this pmd.
-		 */
-		goto clear_pmdnuma;
-	}
-
-	/*
-	 * Page is misplaced. Page lock serialises migrations. Acquire anon_vma
-	 * to serialises splits
-	 */
-	get_page(page);
-	spin_unlock(vmf->ptl);
-	anon_vma = page_lock_anon_vma_read(page);
-
-	/* Confirm the PMD did not change while page_table_lock was released */
-	spin_lock(vmf->ptl);
-	if (unlikely(!pmd_same(pmd, *vmf->pmd))) {
-		unlock_page(page);
-		put_page(page);
-		page_nid = NUMA_NO_NODE;
-		goto out_unlock;
-	}
-
-	/* Bail if we fail to protect against THP splits for any reason */
-	if (unlikely(!anon_vma)) {
-		put_page(page);
-		page_nid = NUMA_NO_NODE;
-		goto clear_pmdnuma;
-	}
-
 	/*
 	 * Since we took the NUMA fault, we must have observed the !accessible
 	 * bit. Make sure all other CPUs agree with that, to avoid them
@@ -1531,43 +1466,58 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
 					      haddr + HPAGE_PMD_SIZE);
 	}
 
-	/*
-	 * Migrate the THP to the requested node, returns with page unlocked
-	 * and access rights restored.
-	 */
+	pmd = pmd_modify(oldpmd, vma->vm_page_prot);
+	page = vm_normal_page_pmd(vma, haddr, pmd);
+	if (!page)
+		goto out_map;
+
+	/* See similar comment in do_numa_page for explanation */
+	if (!was_writable)
+		flags |= TNF_NO_GROUP;
+
+	page_nid = page_to_nid(page);
+	last_cpupid = page_cpupid_last(page);
+	target_nid = numa_migrate_prep(page, vma, haddr, page_nid,
+				       &flags);
+
+	if (target_nid == NUMA_NO_NODE) {
+		put_page(page);
+		goto out_map;
+	}
+
 	spin_unlock(vmf->ptl);
 
-	migrated = migrate_misplaced_transhuge_page(vma->vm_mm, vma,
-				vmf->pmd, pmd, vmf->address, page, target_nid);
+	migrated = migrate_misplaced_page(page, vma, target_nid);
 	if (migrated) {
 		flags |= TNF_MIGRATED;
 		page_nid = target_nid;
-	} else
+	} else {
 		flags |= TNF_MIGRATE_FAIL;
-
-	goto out;
-clear_pmdnuma:
-	BUG_ON(!PageLocked(page));
-	was_writable = pmd_savedwrite(pmd);
-	pmd = pmd_modify(pmd, vma->vm_page_prot);
-	pmd = pmd_mkyoung(pmd);
-	if (was_writable)
-		pmd = pmd_mkwrite(pmd);
-	set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd);
-	update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
-	unlock_page(page);
-out_unlock:
-	spin_unlock(vmf->ptl);
+		vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
+		if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) {
+			spin_unlock(vmf->ptl);
+			goto out;
+		}
+		goto out_map;
+	}
 
 out:
-	if (anon_vma)
-		page_unlock_anon_vma_read(anon_vma);
-
 	if (page_nid != NUMA_NO_NODE)
 		task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR,
 				flags);
 
 	return 0;
+
+out_map:
+	/* Restore the PMD */
+	pmd = pmd_modify(oldpmd, vma->vm_page_prot);
+	pmd = pmd_mkyoung(pmd);
+	if (was_writable)
+		pmd = pmd_mkwrite(pmd);
+	set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd);
+	update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
+	spin_unlock(vmf->ptl);
+	goto out;
 }
 
 /*
@@ -1604,7 +1554,7 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 	 * If other processes are mapping this page, we couldn't discard
 	 * the page unless they all do MADV_FREE so let's skip the page.
 	 */
-	if (page_mapcount(page) != 1)
+	if (total_mapcount(page) != 1)
 		goto out;
 
 	if (!trylock_page(page))
@@ -1677,12 +1627,9 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		if (arch_needs_pgtable_deposit())
 			zap_deposited_table(tlb->mm, pmd);
 		spin_unlock(ptl);
-		if (is_huge_zero_pmd(orig_pmd))
-			tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE);
 	} else if (is_huge_zero_pmd(orig_pmd)) {
 		zap_deposited_table(tlb->mm, pmd);
 		spin_unlock(ptl);
-		tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE);
 	} else {
 		struct page *page = NULL;
 		int flush_needed = 1;
@@ -1697,7 +1644,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 
 			VM_BUG_ON(!is_pmd_migration_entry(orig_pmd));
 			entry = pmd_to_swp_entry(orig_pmd);
-			page = migration_entry_to_page(entry);
+			page = pfn_swap_entry_to_page(entry);
 			flush_needed = 0;
 		} else
 			WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!");
@@ -1796,6 +1743,7 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
  * Returns
  *  - 0 if PMD could not be locked
  *  - 1 if PMD was locked but protections unchanged and TLB flush unnecessary
+ *      or if prot_numa but THP migration is not supported
  *  - HPAGE_PMD_NR if protections changed and TLB flush necessary
  */
 int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
@@ -1810,6 +1758,9 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 	bool uffd_wp = cp_flags & MM_CP_UFFD_WP;
 	bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE;
 
+	if (prot_numa && !thp_migration_supported())
+		return 1;
+
 	ptl = __pmd_trans_huge_lock(pmd, vma);
 	if (!ptl)
 		return 0;
@@ -1822,16 +1773,19 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 		swp_entry_t entry = pmd_to_swp_entry(*pmd);
 
 		VM_BUG_ON(!is_pmd_migration_entry(*pmd));
-		if (is_write_migration_entry(entry)) {
+		if (is_writable_migration_entry(entry)) {
 			pmd_t newpmd;
 			/*
 			 * A protection check is difficult so
 			 * just be safe and disable write
 			 */
-			make_migration_entry_read(&entry);
+			entry = make_readable_migration_entry(
+							swp_offset(entry));
 			newpmd = swp_entry_to_pmd(entry);
 			if (pmd_swp_soft_dirty(*pmd))
 				newpmd = pmd_swp_mksoft_dirty(newpmd);
+			if (pmd_swp_uffd_wp(*pmd))
+				newpmd = pmd_swp_mkuffd_wp(newpmd);
 			set_pmd_at(mm, addr, pmd, newpmd);
 		}
 		goto unlock;
@@ -2060,7 +2014,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 			swp_entry_t entry;
 
 			entry = pmd_to_swp_entry(old_pmd);
-			page = migration_entry_to_page(entry);
+			page = pfn_swap_entry_to_page(entry);
 		} else {
 			page = pmd_page(old_pmd);
 			if (!PageDirty(page) && pmd_dirty(old_pmd))
@@ -2114,8 +2068,8 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 		swp_entry_t entry;
 
 		entry = pmd_to_swp_entry(old_pmd);
-		page = migration_entry_to_page(entry);
-		write = is_write_migration_entry(entry);
+		page = pfn_swap_entry_to_page(entry);
+		write = is_writable_migration_entry(entry);
 		young = false;
 		soft_dirty = pmd_swp_soft_dirty(old_pmd);
 		uffd_wp = pmd_swp_uffd_wp(old_pmd);
@@ -2147,7 +2101,12 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 		 */
 		if (freeze || pmd_migration) {
 			swp_entry_t swp_entry;
-			swp_entry = make_migration_entry(page + i, write);
+			if (write)
+				swp_entry = make_writable_migration_entry(
+							page_to_pfn(page + i));
+			else
+				swp_entry = make_readable_migration_entry(
+							page_to_pfn(page + i));
 			entry = swp_entry_to_pte(swp_entry);
 			if (soft_dirty)
 				entry = pte_swp_mksoft_dirty(entry);
@@ -2350,15 +2309,20 @@ void vma_adjust_trans_huge(struct vm_area_struct *vma,
 
 static void unmap_page(struct page *page)
 {
-	enum ttu_flags ttu_flags = TTU_IGNORE_MLOCK | TTU_SYNC |
-		TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD;
+	enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD |
+		TTU_SYNC;
 
 	VM_BUG_ON_PAGE(!PageHead(page), page);
 
+	/*
+	 * Anon pages need migration entries to preserve them, but file
+	 * pages can simply be left unmapped, then faulted back on demand.
+	 * If that is ever changed (perhaps for mlock), update remap_page().
+	 */
 	if (PageAnon(page))
-		ttu_flags |= TTU_SPLIT_FREEZE;
-
-	try_to_unmap(page, ttu_flags);
+		try_to_migrate(page, ttu_flags);
+	else
+		try_to_unmap(page, ttu_flags | TTU_IGNORE_MLOCK);
 
 	VM_WARN_ON_ONCE_PAGE(page_mapped(page), page);
 }
@@ -2366,6 +2330,10 @@ static void unmap_page(struct page *page)
 static void remap_page(struct page *page, unsigned int nr)
 {
 	int i;
+
+	/* If TTU_SPLIT_FREEZE is ever extended to file, remove this check */
+	if (!PageAnon(page))
+		return;
 	if (PageTransHuge(page)) {
 		remove_migration_ptes(page, page, true);
 	} else {
@@ -2870,7 +2838,7 @@ static unsigned long deferred_split_scan(struct shrinker *shrink,
 	spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
 	/* Take pin on all head pages to avoid freeing them under us */
 	list_for_each_safe(pos, next, &ds_queue->split_queue) {
-		page = list_entry((void *)pos, struct page, mapping);
+		page = list_entry((void *)pos, struct page, deferred_list);
 		page = compound_head(page);
 		if (get_page_unless_zero(page)) {
 			list_move(page_deferred_list(page), &list);
@@ -2885,7 +2853,7 @@ static unsigned long deferred_split_scan(struct shrinker *shrink,
 	spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags);
 
 	list_for_each_safe(pos, next, &list) {
-		page = list_entry((void *)pos, struct page, mapping);
+		page = list_entry((void *)pos, struct page, deferred_list);
 		if (!trylock_page(page))
 			goto next;
 		/* split_huge_page() removes page from list on success */
@@ -3144,7 +3112,7 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf,
 
 		tok = strsep(&buf, ",");
 		if (tok) {
-			strncpy(file_path, tok, MAX_INPUT_BUF_SZ);
+			strcpy(file_path, tok);
 		} else {
 			ret = -EINVAL;
 			goto out;
@@ -3214,7 +3182,10 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
 	pmdval = pmdp_invalidate(vma, address, pvmw->pmd);
 	if (pmd_dirty(pmdval))
 		set_page_dirty(page);
-	entry = make_migration_entry(page, pmd_write(pmdval));
+	if (pmd_write(pmdval))
+		entry = make_writable_migration_entry(page_to_pfn(page));
+	else
+		entry = make_readable_migration_entry(page_to_pfn(page));
 	pmdswp = swp_entry_to_pmd(entry);
 	if (pmd_soft_dirty(pmdval))
 		pmdswp = pmd_swp_mksoft_dirty(pmdswp);
@@ -3240,8 +3211,10 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new)
 	pmde = pmd_mkold(mk_huge_pmd(new, vma->vm_page_prot));
 	if (pmd_swp_soft_dirty(*pvmw->pmd))
 		pmde = pmd_mksoft_dirty(pmde);
-	if (is_write_migration_entry(entry))
+	if (is_writable_migration_entry(entry))
 		pmde = maybe_pmd_mkwrite(pmde, vma);
+	if (pmd_swp_uffd_wp(*pvmw->pmd))
+		pmde = pmd_wrprotect(pmd_mkuffd_wp(pmde));
 
 	flush_cache_range(vma, mmun_start, mmun_start + HPAGE_PMD_SIZE);
 	if (PageAnon(new))
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 103f1187043f..924553aa8f78 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -30,6 +30,7 @@
 #include <linux/numa.h>
 #include <linux/llist.h>
 #include <linux/cma.h>
+#include <linux/migrate.h>
 
 #include <asm/page.h>
 #include <asm/pgalloc.h>
@@ -41,6 +42,7 @@
 #include <linux/node.h>
 #include <linux/page_owner.h>
 #include "internal.h"
+#include "hugetlb_vmemmap.h"
 
 int hugetlb_max_hstate __read_mostly;
 unsigned int default_hstate_idx;
@@ -1318,8 +1320,6 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
 	return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask);
 }
 
-static void prep_new_huge_page(struct hstate *h, struct page *page, int nid);
-static void prep_compound_gigantic_page(struct page *page, unsigned int order);
 #else /* !CONFIG_CONTIG_ALLOC */
 static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
 					int nid, nodemask_t *nodemask)
@@ -1375,7 +1375,40 @@ static void remove_hugetlb_page(struct hstate *h, struct page *page,
 	h->nr_huge_pages_node[nid]--;
 }
 
-static void update_and_free_page(struct hstate *h, struct page *page)
+static void add_hugetlb_page(struct hstate *h, struct page *page,
+			     bool adjust_surplus)
+{
+	int zeroed;
+	int nid = page_to_nid(page);
+
+	VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page);
+
+	lockdep_assert_held(&hugetlb_lock);
+
+	INIT_LIST_HEAD(&page->lru);
+	h->nr_huge_pages++;
+	h->nr_huge_pages_node[nid]++;
+
+	if (adjust_surplus) {
+		h->surplus_huge_pages++;
+		h->surplus_huge_pages_node[nid]++;
+	}
+
+	set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
+	set_page_private(page, 0);
+	SetHPageVmemmapOptimized(page);
+
+	/*
+	 * This page is now managed by the hugetlb allocator and has
+	 * no users -- drop the last reference.
+	 */
+	zeroed = put_page_testzero(page);
+	VM_BUG_ON_PAGE(!zeroed, page);
+	arch_clear_hugepage_flags(page);
+	enqueue_huge_page(h, page);
+}
+
+static void __update_and_free_page(struct hstate *h, struct page *page)
 {
 	int i;
 	struct page *subpage = page;
@@ -1383,6 +1416,18 @@ static void update_and_free_page(struct hstate *h, struct page *page)
 	if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
 		return;
 
+	if (alloc_huge_page_vmemmap(h, page)) {
+		spin_lock_irq(&hugetlb_lock);
+		/*
+		 * If we cannot allocate vmemmap pages, just refuse to free the
+		 * page and put the page back on the hugetlb free list and treat
+		 * as a surplus page.
+		 */
+		add_hugetlb_page(h, page, true);
+		spin_unlock_irq(&hugetlb_lock);
+		return;
+	}
+
 	for (i = 0; i < pages_per_huge_page(h);
 	     i++, subpage = mem_map_next(subpage, page, i)) {
 		subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
@@ -1398,12 +1443,79 @@ static void update_and_free_page(struct hstate *h, struct page *page)
 	}
 }
 
+/*
+ * As update_and_free_page() can be called under any context, so we cannot
+ * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the
+ * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate
+ * the vmemmap pages.
+ *
+ * free_hpage_workfn() locklessly retrieves the linked list of pages to be
+ * freed and frees them one-by-one. As the page->mapping pointer is going
+ * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node
+ * structure of a lockless linked list of huge pages to be freed.
+ */
+static LLIST_HEAD(hpage_freelist);
+
+static void free_hpage_workfn(struct work_struct *work)
+{
+	struct llist_node *node;
+
+	node = llist_del_all(&hpage_freelist);
+
+	while (node) {
+		struct page *page;
+		struct hstate *h;
+
+		page = container_of((struct address_space **)node,
+				     struct page, mapping);
+		node = node->next;
+		page->mapping = NULL;
+		/*
+		 * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate()
+		 * is going to trigger because a previous call to
+		 * remove_hugetlb_page() will set_compound_page_dtor(page,
+		 * NULL_COMPOUND_DTOR), so do not use page_hstate() directly.
+		 */
+		h = size_to_hstate(page_size(page));
+
+		__update_and_free_page(h, page);
+
+		cond_resched();
+	}
+}
+static DECLARE_WORK(free_hpage_work, free_hpage_workfn);
+
+static inline void flush_free_hpage_work(struct hstate *h)
+{
+	if (free_vmemmap_pages_per_hpage(h))
+		flush_work(&free_hpage_work);
+}
+
+static void update_and_free_page(struct hstate *h, struct page *page,
+				 bool atomic)
+{
+	if (!HPageVmemmapOptimized(page) || !atomic) {
+		__update_and_free_page(h, page);
+		return;
+	}
+
+	/*
+	 * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages.
+	 *
+	 * Only call schedule_work() if hpage_freelist is previously
+	 * empty. Otherwise, schedule_work() had been called but the workfn
+	 * hasn't retrieved the list yet.
+	 */
+	if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist))
+		schedule_work(&free_hpage_work);
+}
+
 static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list)
 {
 	struct page *page, *t_page;
 
 	list_for_each_entry_safe(page, t_page, list, lru) {
-		update_and_free_page(h, page);
+		update_and_free_page(h, page, false);
 		cond_resched();
 	}
 }
@@ -1470,12 +1582,12 @@ void free_huge_page(struct page *page)
 	if (HPageTemporary(page)) {
 		remove_hugetlb_page(h, page, false);
 		spin_unlock_irqrestore(&hugetlb_lock, flags);
-		update_and_free_page(h, page);
+		update_and_free_page(h, page, true);
 	} else if (h->surplus_huge_pages_node[nid]) {
 		/* remove the page from active list */
 		remove_hugetlb_page(h, page, true);
 		spin_unlock_irqrestore(&hugetlb_lock, flags);
-		update_and_free_page(h, page);
+		update_and_free_page(h, page, true);
 	} else {
 		arch_clear_hugepage_flags(page);
 		enqueue_huge_page(h, page);
@@ -1493,8 +1605,9 @@ static void __prep_account_new_huge_page(struct hstate *h, int nid)
 	h->nr_huge_pages_node[nid]++;
 }
 
-static void __prep_new_huge_page(struct page *page)
+static void __prep_new_huge_page(struct hstate *h, struct page *page)
 {
+	free_huge_page_vmemmap(h, page);
 	INIT_LIST_HEAD(&page->lru);
 	set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
 	hugetlb_set_page_subpool(page, NULL);
@@ -1504,15 +1617,15 @@ static void __prep_new_huge_page(struct page *page)
 
 static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
 {
-	__prep_new_huge_page(page);
+	__prep_new_huge_page(h, page);
 	spin_lock_irq(&hugetlb_lock);
 	__prep_account_new_huge_page(h, nid);
 	spin_unlock_irq(&hugetlb_lock);
 }
 
-static void prep_compound_gigantic_page(struct page *page, unsigned int order)
+static bool prep_compound_gigantic_page(struct page *page, unsigned int order)
 {
-	int i;
+	int i, j;
 	int nr_pages = 1 << order;
 	struct page *p = page + 1;
 
@@ -1534,11 +1647,48 @@ static void prep_compound_gigantic_page(struct page *page, unsigned int order)
 		 * after get_user_pages().
 		 */
 		__ClearPageReserved(p);
+		/*
+		 * Subtle and very unlikely
+		 *
+		 * Gigantic 'page allocators' such as memblock or cma will
+		 * return a set of pages with each page ref counted.  We need
+		 * to turn this set of pages into a compound page with tail
+		 * page ref counts set to zero.  Code such as speculative page
+		 * cache adding could take a ref on a 'to be' tail page.
+		 * We need to respect any increased ref count, and only set
+		 * the ref count to zero if count is currently 1.  If count
+		 * is not 1, we call synchronize_rcu in the hope that a rcu
+		 * grace period will cause ref count to drop and then retry.
+		 * If count is still inflated on retry we return an error and
+		 * must discard the pages.
+		 */
+		if (!page_ref_freeze(p, 1)) {
+			pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n");
+			synchronize_rcu();
+			if (!page_ref_freeze(p, 1))
+				goto out_error;
+		}
 		set_page_count(p, 0);
 		set_compound_head(p, page);
 	}
 	atomic_set(compound_mapcount_ptr(page), -1);
 	atomic_set(compound_pincount_ptr(page), 0);
+	return true;
+
+out_error:
+	/* undo tail page modifications made above */
+	p = page + 1;
+	for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) {
+		clear_compound_head(p);
+		set_page_refcounted(p);
+	}
+	/* need to clear PG_reserved on remaining tail pages  */
+	for (; j < nr_pages; j++, p = mem_map_next(p, page, j))
+		__ClearPageReserved(p);
+	set_compound_order(page, 0);
+	page[1].compound_nr = 0;
+	__ClearPageHead(page);
+	return false;
 }
 
 /*
@@ -1658,7 +1808,9 @@ static struct page *alloc_fresh_huge_page(struct hstate *h,
 		nodemask_t *node_alloc_noretry)
 {
 	struct page *page;
+	bool retry = false;
 
+retry:
 	if (hstate_is_gigantic(h))
 		page = alloc_gigantic_page(h, gfp_mask, nid, nmask);
 	else
@@ -1667,8 +1819,21 @@ static struct page *alloc_fresh_huge_page(struct hstate *h,
 	if (!page)
 		return NULL;
 
-	if (hstate_is_gigantic(h))
-		prep_compound_gigantic_page(page, huge_page_order(h));
+	if (hstate_is_gigantic(h)) {
+		if (!prep_compound_gigantic_page(page, huge_page_order(h))) {
+			/*
+			 * Rare failure to convert pages to compound page.
+			 * Free pages and try again - ONCE!
+			 */
+			free_gigantic_page(page, huge_page_order(h));
+			if (!retry) {
+				retry = true;
+				goto retry;
+			}
+			pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
+			return NULL;
+		}
+	}
 	prep_new_huge_page(h, page, page_to_nid(page));
 
 	return page;
@@ -1737,10 +1902,14 @@ static struct page *remove_pool_huge_page(struct hstate *h,
  * nothing for in-use hugepages and non-hugepages.
  * This function returns values like below:
  *
- *  -EBUSY: failed to dissolved free hugepages or the hugepage is in-use
- *          (allocated or reserved.)
- *       0: successfully dissolved free hugepages or the page is not a
- *          hugepage (considered as already dissolved)
+ *  -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages
+ *           when the system is under memory pressure and the feature of
+ *           freeing unused vmemmap pages associated with each hugetlb page
+ *           is enabled.
+ *  -EBUSY:  failed to dissolved free hugepages or the hugepage is in-use
+ *           (allocated or reserved.)
+ *       0:  successfully dissolved free hugepages or the page is not a
+ *           hugepage (considered as already dissolved)
  */
 int dissolve_free_huge_page(struct page *page)
 {
@@ -1782,19 +1951,38 @@ retry:
 			goto retry;
 		}
 
-		/*
-		 * Move PageHWPoison flag from head page to the raw error page,
-		 * which makes any subpages rather than the error page reusable.
-		 */
-		if (PageHWPoison(head) && page != head) {
-			SetPageHWPoison(page);
-			ClearPageHWPoison(head);
-		}
 		remove_hugetlb_page(h, head, false);
 		h->max_huge_pages--;
 		spin_unlock_irq(&hugetlb_lock);
-		update_and_free_page(h, head);
-		return 0;
+
+		/*
+		 * Normally update_and_free_page will allocate required vmemmmap
+		 * before freeing the page.  update_and_free_page will fail to
+		 * free the page if it can not allocate required vmemmap.  We
+		 * need to adjust max_huge_pages if the page is not freed.
+		 * Attempt to allocate vmemmmap here so that we can take
+		 * appropriate action on failure.
+		 */
+		rc = alloc_huge_page_vmemmap(h, head);
+		if (!rc) {
+			/*
+			 * Move PageHWPoison flag from head page to the raw
+			 * error page, which makes any subpages rather than
+			 * the error page reusable.
+			 */
+			if (PageHWPoison(head) && page != head) {
+				SetPageHWPoison(page);
+				ClearPageHWPoison(head);
+			}
+			update_and_free_page(h, head, false);
+		} else {
+			spin_lock_irq(&hugetlb_lock);
+			add_hugetlb_page(h, head, false);
+			h->max_huge_pages++;
+			spin_unlock_irq(&hugetlb_lock);
+		}
+
+		return rc;
 	}
 out:
 	spin_unlock_irq(&hugetlb_lock);
@@ -2351,14 +2539,15 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
 
 	/*
 	 * Before dissolving the page, we need to allocate a new one for the
-	 * pool to remain stable. Using alloc_buddy_huge_page() allows us to
-	 * not having to deal with prep_new_huge_page() and avoids dealing of any
-	 * counters. This simplifies and let us do the whole thing under the
-	 * lock.
+	 * pool to remain stable.  Here, we allocate the page and 'prep' it
+	 * by doing everything but actually updating counters and adding to
+	 * the pool.  This simplifies and let us do most of the processing
+	 * under the lock.
 	 */
 	new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL);
 	if (!new_page)
 		return -ENOMEM;
+	__prep_new_huge_page(h, new_page);
 
 retry:
 	spin_lock_irq(&hugetlb_lock);
@@ -2397,14 +2586,9 @@ retry:
 		remove_hugetlb_page(h, old_page, false);
 
 		/*
-		 * new_page needs to be initialized with the standard hugetlb
-		 * state. This is normally done by prep_new_huge_page() but
-		 * that takes hugetlb_lock which is already held so we need to
-		 * open code it here.
 		 * Reference count trick is needed because allocator gives us
 		 * referenced page but the pool requires pages with 0 refcount.
 		 */
-		__prep_new_huge_page(new_page);
 		__prep_account_new_huge_page(h, nid);
 		page_ref_dec(new_page);
 		enqueue_huge_page(h, new_page);
@@ -2413,14 +2597,14 @@ retry:
 		 * Pages have been replaced, we can safely free the old one.
 		 */
 		spin_unlock_irq(&hugetlb_lock);
-		update_and_free_page(h, old_page);
+		update_and_free_page(h, old_page, false);
 	}
 
 	return ret;
 
 free_new:
 	spin_unlock_irq(&hugetlb_lock);
-	__free_pages(new_page, huge_page_order(h));
+	update_and_free_page(h, new_page, false);
 
 	return ret;
 }
@@ -2625,16 +2809,10 @@ found:
 	return 1;
 }
 
-static void __init prep_compound_huge_page(struct page *page,
-		unsigned int order)
-{
-	if (unlikely(order > (MAX_ORDER - 1)))
-		prep_compound_gigantic_page(page, order);
-	else
-		prep_compound_page(page, order);
-}
-
-/* Put bootmem huge pages into the standard lists after mem_map is up */
+/*
+ * Put bootmem huge pages into the standard lists after mem_map is up.
+ * Note: This only applies to gigantic (order > MAX_ORDER) pages.
+ */
 static void __init gather_bootmem_prealloc(void)
 {
 	struct huge_bootmem_page *m;
@@ -2643,20 +2821,23 @@ static void __init gather_bootmem_prealloc(void)
 		struct page *page = virt_to_page(m);
 		struct hstate *h = m->hstate;
 
+		VM_BUG_ON(!hstate_is_gigantic(h));
 		WARN_ON(page_count(page) != 1);
-		prep_compound_huge_page(page, huge_page_order(h));
-		WARN_ON(PageReserved(page));
-		prep_new_huge_page(h, page, page_to_nid(page));
-		put_page(page); /* free it into the hugepage allocator */
+		if (prep_compound_gigantic_page(page, huge_page_order(h))) {
+			WARN_ON(PageReserved(page));
+			prep_new_huge_page(h, page, page_to_nid(page));
+			put_page(page); /* add to the hugepage allocator */
+		} else {
+			free_gigantic_page(page, huge_page_order(h));
+			pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
+		}
 
 		/*
-		 * If we had gigantic hugepages allocated at boot time, we need
-		 * to restore the 'stolen' pages to totalram_pages in order to
-		 * fix confusing memory reports from free(1) and another
-		 * side-effects, like CommitLimit going negative.
+		 * We need to restore the 'stolen' pages to totalram_pages
+		 * in order to fix confusing memory reports from free(1) and
+		 * other side-effects, like CommitLimit going negative.
 		 */
-		if (hstate_is_gigantic(h))
-			adjust_managed_page_count(page, pages_per_huge_page(h));
+		adjust_managed_page_count(page, pages_per_huge_page(h));
 		cond_resched();
 	}
 }
@@ -2834,6 +3015,7 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
 	 * pages in hstate via the proc/sysfs interfaces.
 	 */
 	mutex_lock(&h->resize_lock);
+	flush_free_hpage_work(h);
 	spin_lock_irq(&hugetlb_lock);
 
 	/*
@@ -2943,6 +3125,7 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
 	/* free the pages after dropping lock */
 	spin_unlock_irq(&hugetlb_lock);
 	update_and_free_pages_bulk(h, &page_list);
+	flush_free_hpage_work(h);
 	spin_lock_irq(&hugetlb_lock);
 
 	while (count < persistent_huge_pages(h)) {
@@ -3450,6 +3633,7 @@ void __init hugetlb_add_hstate(unsigned int order)
 	h->next_nid_to_free = first_memory_node;
 	snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
 					huge_page_size(h)/1024);
+	hugetlb_vmemmap_init(h);
 
 	parsed_hstate = h;
 }
@@ -3924,6 +4108,7 @@ static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
 				int writable)
 {
 	pte_t entry;
+	unsigned int shift = huge_page_shift(hstate_vma(vma));
 
 	if (writable) {
 		entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page,
@@ -3934,7 +4119,7 @@ static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
 	}
 	entry = pte_mkyoung(entry);
 	entry = pte_mkhuge(entry);
-	entry = arch_make_huge_pte(entry, vma, page, writable);
+	entry = arch_make_huge_pte(entry, shift, vma->vm_flags);
 
 	return entry;
 }
@@ -4057,12 +4242,13 @@ again:
 				    is_hugetlb_entry_hwpoisoned(entry))) {
 			swp_entry_t swp_entry = pte_to_swp_entry(entry);
 
-			if (is_write_migration_entry(swp_entry) && cow) {
+			if (is_writable_migration_entry(swp_entry) && cow) {
 				/*
 				 * COW mappings require pages in both
 				 * parent and child to be set to read.
 				 */
-				make_migration_entry_read(&swp_entry);
+				swp_entry = make_readable_migration_entry(
+							swp_offset(swp_entry));
 				entry = swp_entry_to_pte(swp_entry);
 				set_huge_swap_pte_at(src, addr, src_pte,
 						     entry, sz);
@@ -4939,20 +5125,17 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    struct page **pagep)
 {
 	bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE);
-	struct address_space *mapping;
-	pgoff_t idx;
+	struct hstate *h = hstate_vma(dst_vma);
+	struct address_space *mapping = dst_vma->vm_file->f_mapping;
+	pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);
 	unsigned long size;
 	int vm_shared = dst_vma->vm_flags & VM_SHARED;
-	struct hstate *h = hstate_vma(dst_vma);
 	pte_t _dst_pte;
 	spinlock_t *ptl;
-	int ret;
+	int ret = -ENOMEM;
 	struct page *page;
 	int writable;
 
-	mapping = dst_vma->vm_file->f_mapping;
-	idx = vma_hugecache_offset(h, dst_vma, dst_addr);
-
 	if (is_continue) {
 		ret = -EFAULT;
 		page = find_lock_page(mapping, idx);
@@ -4981,12 +5164,44 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 		/* fallback to copy_from_user outside mmap_lock */
 		if (unlikely(ret)) {
 			ret = -ENOENT;
+			/* Free the allocated page which may have
+			 * consumed a reservation.
+			 */
+			restore_reserve_on_error(h, dst_vma, dst_addr, page);
+			put_page(page);
+
+			/* Allocate a temporary page to hold the copied
+			 * contents.
+			 */
+			page = alloc_huge_page_vma(h, dst_vma, dst_addr);
+			if (!page) {
+				ret = -ENOMEM;
+				goto out;
+			}
 			*pagep = page;
-			/* don't free the page */
+			/* Set the outparam pagep and return to the caller to
+			 * copy the contents outside the lock. Don't free the
+			 * page.
+			 */
 			goto out;
 		}
 	} else {
-		page = *pagep;
+		if (vm_shared &&
+		    hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
+			put_page(*pagep);
+			ret = -EEXIST;
+			*pagep = NULL;
+			goto out;
+		}
+
+		page = alloc_huge_page(dst_vma, dst_addr, 0);
+		if (IS_ERR(page)) {
+			ret = -ENOMEM;
+			*pagep = NULL;
+			goto out;
+		}
+		copy_huge_page(page, *pagep);
+		put_page(*pagep);
 		*pagep = NULL;
 	}
 
@@ -5318,10 +5533,11 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
 		if (unlikely(is_hugetlb_entry_migration(pte))) {
 			swp_entry_t entry = pte_to_swp_entry(pte);
 
-			if (is_write_migration_entry(entry)) {
+			if (is_writable_migration_entry(entry)) {
 				pte_t newpte;
 
-				make_migration_entry_read(&entry);
+				entry = make_readable_migration_entry(
+							swp_offset(entry));
 				newpte = swp_entry_to_pte(entry);
 				set_huge_swap_pte_at(mm, address, ptep,
 						     newpte, huge_page_size(h));
@@ -5332,10 +5548,11 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
 		}
 		if (!huge_pte_none(pte)) {
 			pte_t old_pte;
+			unsigned int shift = huge_page_shift(hstate_vma(vma));
 
 			old_pte = huge_ptep_modify_prot_start(vma, address, ptep);
 			pte = pte_mkhuge(huge_pte_modify(old_pte, newprot));
-			pte = arch_make_huge_pte(pte, vma, NULL, 0);
+			pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
 			huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte);
 			pages++;
 		}
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
new file mode 100644
index 000000000000..c540c21e26f5
--- /dev/null
+++ b/mm/hugetlb_vmemmap.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Free some vmemmap pages of HugeTLB
+ *
+ * Copyright (c) 2020, Bytedance. All rights reserved.
+ *
+ *     Author: Muchun Song <songmuchun@bytedance.com>
+ *
+ * The struct page structures (page structs) are used to describe a physical
+ * page frame. By default, there is a one-to-one mapping from a page frame to
+ * it's corresponding page struct.
+ *
+ * HugeTLB pages consist of multiple base page size pages and is supported by
+ * many architectures. See hugetlbpage.rst in the Documentation directory for
+ * more details. On the x86-64 architecture, HugeTLB pages of size 2MB and 1GB
+ * are currently supported. Since the base page size on x86 is 4KB, a 2MB
+ * HugeTLB page consists of 512 base pages and a 1GB HugeTLB page consists of
+ * 4096 base pages. For each base page, there is a corresponding page struct.
+ *
+ * Within the HugeTLB subsystem, only the first 4 page structs are used to
+ * contain unique information about a HugeTLB page. __NR_USED_SUBPAGE provides
+ * this upper limit. The only 'useful' information in the remaining page structs
+ * is the compound_head field, and this field is the same for all tail pages.
+ *
+ * By removing redundant page structs for HugeTLB pages, memory can be returned
+ * to the buddy allocator for other uses.
+ *
+ * Different architectures support different HugeTLB pages. For example, the
+ * following table is the HugeTLB page size supported by x86 and arm64
+ * architectures. Because arm64 supports 4k, 16k, and 64k base pages and
+ * supports contiguous entries, so it supports many kinds of sizes of HugeTLB
+ * page.
+ *
+ * +--------------+-----------+-----------------------------------------------+
+ * | Architecture | Page Size |                HugeTLB Page Size              |
+ * +--------------+-----------+-----------+-----------+-----------+-----------+
+ * |    x86-64    |    4KB    |    2MB    |    1GB    |           |           |
+ * +--------------+-----------+-----------+-----------+-----------+-----------+
+ * |              |    4KB    |   64KB    |    2MB    |    32MB   |    1GB    |
+ * |              +-----------+-----------+-----------+-----------+-----------+
+ * |    arm64     |   16KB    |    2MB    |   32MB    |     1GB   |           |
+ * |              +-----------+-----------+-----------+-----------+-----------+
+ * |              |   64KB    |    2MB    |  512MB    |    16GB   |           |
+ * +--------------+-----------+-----------+-----------+-----------+-----------+
+ *
+ * When the system boot up, every HugeTLB page has more than one struct page
+ * structs which size is (unit: pages):
+ *
+ *    struct_size = HugeTLB_Size / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE
+ *
+ * Where HugeTLB_Size is the size of the HugeTLB page. We know that the size
+ * of the HugeTLB page is always n times PAGE_SIZE. So we can get the following
+ * relationship.
+ *
+ *    HugeTLB_Size = n * PAGE_SIZE
+ *
+ * Then,
+ *
+ *    struct_size = n * PAGE_SIZE / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE
+ *                = n * sizeof(struct page) / PAGE_SIZE
+ *
+ * We can use huge mapping at the pud/pmd level for the HugeTLB page.
+ *
+ * For the HugeTLB page of the pmd level mapping, then
+ *
+ *    struct_size = n * sizeof(struct page) / PAGE_SIZE
+ *                = PAGE_SIZE / sizeof(pte_t) * sizeof(struct page) / PAGE_SIZE
+ *                = sizeof(struct page) / sizeof(pte_t)
+ *                = 64 / 8
+ *                = 8 (pages)
+ *
+ * Where n is how many pte entries which one page can contains. So the value of
+ * n is (PAGE_SIZE / sizeof(pte_t)).
+ *
+ * This optimization only supports 64-bit system, so the value of sizeof(pte_t)
+ * is 8. And this optimization also applicable only when the size of struct page
+ * is a power of two. In most cases, the size of struct page is 64 bytes (e.g.
+ * x86-64 and arm64). So if we use pmd level mapping for a HugeTLB page, the
+ * size of struct page structs of it is 8 page frames which size depends on the
+ * size of the base page.
+ *
+ * For the HugeTLB page of the pud level mapping, then
+ *
+ *    struct_size = PAGE_SIZE / sizeof(pmd_t) * struct_size(pmd)
+ *                = PAGE_SIZE / 8 * 8 (pages)
+ *                = PAGE_SIZE (pages)
+ *
+ * Where the struct_size(pmd) is the size of the struct page structs of a
+ * HugeTLB page of the pmd level mapping.
+ *
+ * E.g.: A 2MB HugeTLB page on x86_64 consists in 8 page frames while 1GB
+ * HugeTLB page consists in 4096.
+ *
+ * Next, we take the pmd level mapping of the HugeTLB page as an example to
+ * show the internal implementation of this optimization. There are 8 pages
+ * struct page structs associated with a HugeTLB page which is pmd mapped.
+ *
+ * Here is how things look before optimization.
+ *
+ *    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
+ * +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
+ * |           |                     |     0     | -------------> |     0     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     1     | -------------> |     1     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     2     | -------------> |     2     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     3     | -------------> |     3     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     4     | -------------> |     4     |
+ * |    PMD    |                     +-----------+                +-----------+
+ * |   level   |                     |     5     | -------------> |     5     |
+ * |  mapping  |                     +-----------+                +-----------+
+ * |           |                     |     6     | -------------> |     6     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     7     | -------------> |     7     |
+ * |           |                     +-----------+                +-----------+
+ * |           |
+ * |           |
+ * |           |
+ * +-----------+
+ *
+ * The value of page->compound_head is the same for all tail pages. The first
+ * page of page structs (page 0) associated with the HugeTLB page contains the 4
+ * page structs necessary to describe the HugeTLB. The only use of the remaining
+ * pages of page structs (page 1 to page 7) is to point to page->compound_head.
+ * Therefore, we can remap pages 2 to 7 to page 1. Only 2 pages of page structs
+ * will be used for each HugeTLB page. This will allow us to free the remaining
+ * 6 pages to the buddy allocator.
+ *
+ * Here is how things look after remapping.
+ *
+ *    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
+ * +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
+ * |           |                     |     0     | -------------> |     0     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     1     | -------------> |     1     |
+ * |           |                     +-----------+                +-----------+
+ * |           |                     |     2     | ----------------^ ^ ^ ^ ^ ^
+ * |           |                     +-----------+                   | | | | |
+ * |           |                     |     3     | ------------------+ | | | |
+ * |           |                     +-----------+                     | | | |
+ * |           |                     |     4     | --------------------+ | | |
+ * |    PMD    |                     +-----------+                       | | |
+ * |   level   |                     |     5     | ----------------------+ | |
+ * |  mapping  |                     +-----------+                         | |
+ * |           |                     |     6     | ------------------------+ |
+ * |           |                     +-----------+                           |
+ * |           |                     |     7     | --------------------------+
+ * |           |                     +-----------+
+ * |           |
+ * |           |
+ * |           |
+ * +-----------+
+ *
+ * When a HugeTLB is freed to the buddy system, we should allocate 6 pages for
+ * vmemmap pages and restore the previous mapping relationship.
+ *
+ * For the HugeTLB page of the pud level mapping. It is similar to the former.
+ * We also can use this approach to free (PAGE_SIZE - 2) vmemmap pages.
+ *
+ * Apart from the HugeTLB page of the pmd/pud level mapping, some architectures
+ * (e.g. aarch64) provides a contiguous bit in the translation table entries
+ * that hints to the MMU to indicate that it is one of a contiguous set of
+ * entries that can be cached in a single TLB entry.
+ *
+ * The contiguous bit is used to increase the mapping size at the pmd and pte
+ * (last) level. So this type of HugeTLB page can be optimized only when its
+ * size of the struct page structs is greater than 2 pages.
+ */
+#define pr_fmt(fmt)	"HugeTLB: " fmt
+
+#include "hugetlb_vmemmap.h"
+
+/*
+ * There are a lot of struct page structures associated with each HugeTLB page.
+ * For tail pages, the value of compound_head is the same. So we can reuse first
+ * page of tail page structures. We map the virtual addresses of the remaining
+ * pages of tail page structures to the first tail page struct, and then free
+ * these page frames. Therefore, we need to reserve two pages as vmemmap areas.
+ */
+#define RESERVE_VMEMMAP_NR		2U
+#define RESERVE_VMEMMAP_SIZE		(RESERVE_VMEMMAP_NR << PAGE_SHIFT)
+
+bool hugetlb_free_vmemmap_enabled = IS_ENABLED(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON);
+
+static int __init early_hugetlb_free_vmemmap_param(char *buf)
+{
+	/* We cannot optimize if a "struct page" crosses page boundaries. */
+	if ((!is_power_of_2(sizeof(struct page)))) {
+		pr_warn("cannot free vmemmap pages because \"struct page\" crosses page boundaries\n");
+		return 0;
+	}
+
+	if (!buf)
+		return -EINVAL;
+
+	if (!strcmp(buf, "on"))
+		hugetlb_free_vmemmap_enabled = true;
+	else if (!strcmp(buf, "off"))
+		hugetlb_free_vmemmap_enabled = false;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param);
+
+static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h)
+{
+	return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT;
+}
+
+/*
+ * Previously discarded vmemmap pages will be allocated and remapping
+ * after this function returns zero.
+ */
+int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
+{
+	int ret;
+	unsigned long vmemmap_addr = (unsigned long)head;
+	unsigned long vmemmap_end, vmemmap_reuse;
+
+	if (!HPageVmemmapOptimized(head))
+		return 0;
+
+	vmemmap_addr += RESERVE_VMEMMAP_SIZE;
+	vmemmap_end = vmemmap_addr + free_vmemmap_pages_size_per_hpage(h);
+	vmemmap_reuse = vmemmap_addr - PAGE_SIZE;
+	/*
+	 * The pages which the vmemmap virtual address range [@vmemmap_addr,
+	 * @vmemmap_end) are mapped to are freed to the buddy allocator, and
+	 * the range is mapped to the page which @vmemmap_reuse is mapped to.
+	 * When a HugeTLB page is freed to the buddy allocator, previously
+	 * discarded vmemmap pages must be allocated and remapping.
+	 */
+	ret = vmemmap_remap_alloc(vmemmap_addr, vmemmap_end, vmemmap_reuse,
+				  GFP_KERNEL | __GFP_NORETRY | __GFP_THISNODE);
+
+	if (!ret)
+		ClearHPageVmemmapOptimized(head);
+
+	return ret;
+}
+
+void free_huge_page_vmemmap(struct hstate *h, struct page *head)
+{
+	unsigned long vmemmap_addr = (unsigned long)head;
+	unsigned long vmemmap_end, vmemmap_reuse;
+
+	if (!free_vmemmap_pages_per_hpage(h))
+		return;
+
+	vmemmap_addr += RESERVE_VMEMMAP_SIZE;
+	vmemmap_end = vmemmap_addr + free_vmemmap_pages_size_per_hpage(h);
+	vmemmap_reuse = vmemmap_addr - PAGE_SIZE;
+
+	/*
+	 * Remap the vmemmap virtual address range [@vmemmap_addr, @vmemmap_end)
+	 * to the page which @vmemmap_reuse is mapped to, then free the pages
+	 * which the range [@vmemmap_addr, @vmemmap_end] is mapped to.
+	 */
+	if (!vmemmap_remap_free(vmemmap_addr, vmemmap_end, vmemmap_reuse))
+		SetHPageVmemmapOptimized(head);
+}
+
+void __init hugetlb_vmemmap_init(struct hstate *h)
+{
+	unsigned int nr_pages = pages_per_huge_page(h);
+	unsigned int vmemmap_pages;
+
+	/*
+	 * There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct
+	 * page structs that can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP,
+	 * so add a BUILD_BUG_ON to catch invalid usage of the tail struct page.
+	 */
+	BUILD_BUG_ON(__NR_USED_SUBPAGE >=
+		     RESERVE_VMEMMAP_SIZE / sizeof(struct page));
+
+	if (!hugetlb_free_vmemmap_enabled)
+		return;
+
+	vmemmap_pages = (nr_pages * sizeof(struct page)) >> PAGE_SHIFT;
+	/*
+	 * The head page and the first tail page are not to be freed to buddy
+	 * allocator, the other pages will map to the first tail page, so they
+	 * can be freed.
+	 *
+	 * Could RESERVE_VMEMMAP_NR be greater than @vmemmap_pages? It is true
+	 * on some architectures (e.g. aarch64). See Documentation/arm64/
+	 * hugetlbpage.rst for more details.
+	 */
+	if (likely(vmemmap_pages > RESERVE_VMEMMAP_NR))
+		h->nr_free_vmemmap_pages = vmemmap_pages - RESERVE_VMEMMAP_NR;
+
+	pr_info("can free %d vmemmap pages for %s\n", h->nr_free_vmemmap_pages,
+		h->name);
+}
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
new file mode 100644
index 000000000000..cb2bef8f9e73
--- /dev/null
+++ b/mm/hugetlb_vmemmap.h
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Free some vmemmap pages of HugeTLB
+ *
+ * Copyright (c) 2020, Bytedance. All rights reserved.
+ *
+ *     Author: Muchun Song <songmuchun@bytedance.com>
+ */
+#ifndef _LINUX_HUGETLB_VMEMMAP_H
+#define _LINUX_HUGETLB_VMEMMAP_H
+#include <linux/hugetlb.h>
+
+#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+int alloc_huge_page_vmemmap(struct hstate *h, struct page *head);
+void free_huge_page_vmemmap(struct hstate *h, struct page *head);
+void hugetlb_vmemmap_init(struct hstate *h);
+
+/*
+ * How many vmemmap pages associated with a HugeTLB page that can be freed
+ * to the buddy allocator.
+ */
+static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
+{
+	return h->nr_free_vmemmap_pages;
+}
+#else
+static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
+{
+	return 0;
+}
+
+static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head)
+{
+}
+
+static inline void hugetlb_vmemmap_init(struct hstate *h)
+{
+}
+
+static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
+{
+	return 0;
+}
+#endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */
+#endif /* _LINUX_HUGETLB_VMEMMAP_H */
diff --git a/mm/internal.h b/mm/internal.h
index 6ec2cea9926b..2d7c9a2e0118 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -274,11 +274,10 @@ isolate_freepages_range(struct compact_control *cc,
 int
 isolate_migratepages_range(struct compact_control *cc,
 			   unsigned long low_pfn, unsigned long end_pfn);
+#endif
 int find_suitable_fallback(struct free_area *area, unsigned int order,
 			int migratetype, bool only_stealable, bool *can_steal);
 
-#endif
-
 /*
  * This function returns the order of a free page in the buddy system. In
  * general, page_zone(page)->lock must be held by the caller to prevent the
@@ -344,7 +343,10 @@ void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
 
 #ifdef CONFIG_MMU
 extern long populate_vma_page_range(struct vm_area_struct *vma,
-		unsigned long start, unsigned long end, int *nonblocking);
+		unsigned long start, unsigned long end, int *locked);
+extern long faultin_vma_page_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end,
+				   bool write, int *locked);
 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
 			unsigned long start, unsigned long end);
 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
@@ -369,23 +371,6 @@ extern unsigned int munlock_vma_page(struct page *page);
  */
 extern void clear_page_mlock(struct page *page);
 
-/*
- * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
- * (because that does not go through the full procedure of migration ptes):
- * to migrate the Mlocked page flag; update statistics.
- */
-static inline void mlock_migrate_page(struct page *newpage, struct page *page)
-{
-	if (TestClearPageMlocked(page)) {
-		int nr_pages = thp_nr_pages(page);
-
-		/* Holding pmd lock, no change in irq context: __mod is safe */
-		__mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
-		SetPageMlocked(newpage);
-		__mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
-	}
-}
-
 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
 
 /*
@@ -461,7 +446,6 @@ static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
 #else /* !CONFIG_MMU */
 static inline void clear_page_mlock(struct page *page) { }
 static inline void mlock_vma_page(struct page *page) { }
-static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
 {
 }
@@ -672,4 +656,7 @@ int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
 
 void vunmap_range_noflush(unsigned long start, unsigned long end);
 
+int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
+		      unsigned long addr, int page_nid, int *flags);
+
 #endif	/* __MM_INTERNAL_H */
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 4d21ac44d5d3..d7666ace9d2e 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -636,7 +636,7 @@ static void toggle_allocation_gate(struct work_struct *work)
 	/* Disable static key and reset timer. */
 	static_branch_disable(&kfence_allocation_key);
 #endif
-	queue_delayed_work(system_power_efficient_wq, &kfence_timer,
+	queue_delayed_work(system_unbound_wq, &kfence_timer,
 			   msecs_to_jiffies(kfence_sample_interval));
 }
 static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate);
@@ -666,7 +666,7 @@ void __init kfence_init(void)
 	}
 
 	WRITE_ONCE(kfence_enabled, true);
-	queue_delayed_work(system_power_efficient_wq, &kfence_timer, 0);
+	queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
 	pr_info("initialized - using %lu bytes for %d objects at 0x%p-0x%p\n", KFENCE_POOL_SIZE,
 		CONFIG_KFENCE_NUM_OBJECTS, (void *)__kfence_pool,
 		(void *)(__kfence_pool + KFENCE_POOL_SIZE));
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 6c0185fdd815..b0412be08fa2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -442,9 +442,7 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
 static bool hugepage_vma_check(struct vm_area_struct *vma,
 			       unsigned long vm_flags)
 {
-	/* Explicitly disabled through madvise. */
-	if ((vm_flags & VM_NOHUGEPAGE) ||
-	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+	if (!transhuge_vma_enabled(vma, vm_flags))
 		return false;
 
 	/* Enabled via shmem mount options or sysfs settings. */
@@ -459,7 +457,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma,
 
 	/* Read-only file mappings need to be aligned for THP to work. */
 	if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && vma->vm_file &&
-	    (vm_flags & VM_DENYWRITE)) {
+	    !inode_is_open_for_write(vma->vm_file->f_inode) &&
+	    (vm_flags & VM_EXEC)) {
 		return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
 				HPAGE_PMD_NR);
 	}
@@ -1864,6 +1863,19 @@ out_unlock:
 	else {
 		__mod_lruvec_page_state(new_page, NR_FILE_THPS, nr);
 		filemap_nr_thps_inc(mapping);
+		/*
+		 * Paired with smp_mb() in do_dentry_open() to ensure
+		 * i_writecount is up to date and the update to nr_thps is
+		 * visible. Ensures the page cache will be truncated if the
+		 * file is opened writable.
+		 */
+		smp_mb();
+		if (inode_is_open_for_write(mapping->host)) {
+			result = SCAN_FAIL;
+			__mod_lruvec_page_state(new_page, NR_FILE_THPS, -nr);
+			filemap_nr_thps_dec(mapping);
+			goto xa_locked;
+		}
 	}
 
 	if (nr_none) {
diff --git a/mm/madvise.c b/mm/madvise.c
index 63e489e5bfdb..6d3d348b17f4 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -53,6 +53,8 @@ static int madvise_need_mmap_write(int behavior)
 	case MADV_COLD:
 	case MADV_PAGEOUT:
 	case MADV_FREE:
+	case MADV_POPULATE_READ:
+	case MADV_POPULATE_WRITE:
 		return 0;
 	default:
 		/* be safe, default to 1. list exceptions explicitly */
@@ -822,6 +824,61 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
 		return -EINVAL;
 }
 
+static long madvise_populate(struct vm_area_struct *vma,
+			     struct vm_area_struct **prev,
+			     unsigned long start, unsigned long end,
+			     int behavior)
+{
+	const bool write = behavior == MADV_POPULATE_WRITE;
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long tmp_end;
+	int locked = 1;
+	long pages;
+
+	*prev = vma;
+
+	while (start < end) {
+		/*
+		 * We might have temporarily dropped the lock. For example,
+		 * our VMA might have been split.
+		 */
+		if (!vma || start >= vma->vm_end) {
+			vma = find_vma(mm, start);
+			if (!vma || start < vma->vm_start)
+				return -ENOMEM;
+		}
+
+		tmp_end = min_t(unsigned long, end, vma->vm_end);
+		/* Populate (prefault) page tables readable/writable. */
+		pages = faultin_vma_page_range(vma, start, tmp_end, write,
+					       &locked);
+		if (!locked) {
+			mmap_read_lock(mm);
+			locked = 1;
+			*prev = NULL;
+			vma = NULL;
+		}
+		if (pages < 0) {
+			switch (pages) {
+			case -EINTR:
+				return -EINTR;
+			case -EFAULT: /* Incompatible mappings / permissions. */
+				return -EINVAL;
+			case -EHWPOISON:
+				return -EHWPOISON;
+			default:
+				pr_warn_once("%s: unhandled return value: %ld\n",
+					     __func__, pages);
+				fallthrough;
+			case -ENOMEM:
+				return -ENOMEM;
+			}
+		}
+		start += pages * PAGE_SIZE;
+	}
+	return 0;
+}
+
 /*
  * Application wants to free up the pages and associated backing store.
  * This is effectively punching a hole into the middle of a file.
@@ -935,6 +992,9 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 	case MADV_FREE:
 	case MADV_DONTNEED:
 		return madvise_dontneed_free(vma, prev, start, end, behavior);
+	case MADV_POPULATE_READ:
+	case MADV_POPULATE_WRITE:
+		return madvise_populate(vma, prev, start, end, behavior);
 	default:
 		return madvise_behavior(vma, prev, start, end, behavior);
 	}
@@ -955,6 +1015,8 @@ madvise_behavior_valid(int behavior)
 	case MADV_FREE:
 	case MADV_COLD:
 	case MADV_PAGEOUT:
+	case MADV_POPULATE_READ:
+	case MADV_POPULATE_WRITE:
 #ifdef CONFIG_KSM
 	case MADV_MERGEABLE:
 	case MADV_UNMERGEABLE:
@@ -1042,6 +1104,10 @@ process_madvise_behavior_valid(int behavior)
  *		easily if memory pressure happens.
  *  MADV_PAGEOUT - the application is not expected to use this memory soon,
  *		page out the pages in this range immediately.
+ *  MADV_POPULATE_READ - populate (prefault) page tables readable by
+ *		triggering read faults if required
+ *  MADV_POPULATE_WRITE - populate (prefault) page tables writable by
+ *		triggering write faults if required
  *
  * return values:
  *  zero    - success
diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c
index b890854ec761..ea734f248fce 100644
--- a/mm/mapping_dirty_helpers.c
+++ b/mm/mapping_dirty_helpers.c
@@ -317,7 +317,7 @@ EXPORT_SYMBOL_GPL(wp_shared_mapping_range);
  * pfn_mkwrite(). And then after a TLB flush following the write-protection
  * pick up all dirty bits.
  *
- * Note: This function currently skips transhuge page-table entries, since
+ * This function currently skips transhuge page-table entries, since
  * it's intended for dirty-tracking on the PTE level. It will warn on
  * encountering transhuge dirty entries, though, and can easily be extended
  * to handle them as well.
diff --git a/mm/memblock.c b/mm/memblock.c
index 123feef5259d..3e4acbf03ab7 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -906,6 +906,11 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
+ * The memory regions marked with %MEMBLOCK_NOMAP will not be added to the
+ * direct mapping of the physical memory. These regions will still be
+ * covered by the memory map. The struct page representing NOMAP memory
+ * frames in the memory map will be PageReserved()
+ *
  * Return: 0 on success, -errno on failure.
  */
 int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)
@@ -2002,6 +2007,26 @@ static unsigned long __init __free_memory_core(phys_addr_t start,
 	return end_pfn - start_pfn;
 }
 
+static void __init memmap_init_reserved_pages(void)
+{
+	struct memblock_region *region;
+	phys_addr_t start, end;
+	u64 i;
+
+	/* initialize struct pages for the reserved regions */
+	for_each_reserved_mem_range(i, &start, &end)
+		reserve_bootmem_region(start, end);
+
+	/* and also treat struct pages for the NOMAP regions as PageReserved */
+	for_each_mem_region(region) {
+		if (memblock_is_nomap(region)) {
+			start = region->base;
+			end = start + region->size;
+			reserve_bootmem_region(start, end);
+		}
+	}
+}
+
 static unsigned long __init free_low_memory_core_early(void)
 {
 	unsigned long count = 0;
@@ -2010,8 +2035,7 @@ static unsigned long __init free_low_memory_core_early(void)
 
 	memblock_clear_hotplug(0, -1);
 
-	for_each_reserved_mem_range(i, &start, &end)
-		reserve_bootmem_region(start, end);
+	memmap_init_reserved_pages();
 
 	/*
 	 * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b80aae448a49..ae1f5d0cb581 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5537,7 +5537,7 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
 	 * as special swap entry in the CPU page table.
 	 */
 	if (is_device_private_entry(ent)) {
-		page = device_private_entry_to_page(ent);
+		page = pfn_swap_entry_to_page(ent);
 		/*
 		 * MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have
 		 * a refcount of 1 when free (unlike normal page)
@@ -6644,7 +6644,7 @@ static unsigned long effective_protection(unsigned long usage,
 }
 
 /**
- * mem_cgroup_protected - check if memory consumption is in the normal range
+ * mem_cgroup_calculate_protection - check if memory consumption is in the normal range
  * @root: the top ancestor of the sub-tree being checked
  * @memcg: the memory cgroup to check
  *
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e5a1531f7f4e..eefd823deb67 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -66,6 +66,19 @@ int sysctl_memory_failure_recovery __read_mostly = 1;
 
 atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
 
+static bool __page_handle_poison(struct page *page)
+{
+	bool ret;
+
+	zone_pcp_disable(page_zone(page));
+	ret = dissolve_free_huge_page(page);
+	if (!ret)
+		ret = take_page_off_buddy(page);
+	zone_pcp_enable(page_zone(page));
+
+	return ret;
+}
+
 static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release)
 {
 	if (hugepage_or_freepage) {
@@ -73,7 +86,7 @@ static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, boo
 		 * Doing this check for free pages is also fine since dissolve_free_huge_page
 		 * returns 0 for non-hugetlb pages as well.
 		 */
-		if (dissolve_free_huge_page(page) || !take_page_off_buddy(page))
+		if (!__page_handle_poison(page))
 			/*
 			 * We could fail to take off the target page from buddy
 			 * for example due to racy page allocation, but that's
@@ -985,7 +998,7 @@ static int me_huge_page(struct page *p, unsigned long pfn)
 		 */
 		if (PageAnon(hpage))
 			put_page(hpage);
-		if (!dissolve_free_huge_page(p) && take_page_off_buddy(p)) {
+		if (__page_handle_poison(p)) {
 			page_ref_inc(p);
 			res = MF_RECOVERED;
 		}
@@ -1253,10 +1266,10 @@ static int get_hwpoison_page(struct page *p, unsigned long flags)
 static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
 				  int flags, struct page **hpagep)
 {
-	enum ttu_flags ttu = TTU_IGNORE_MLOCK;
+	enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC;
 	struct address_space *mapping;
 	LIST_HEAD(tokill);
-	bool unmap_success = true;
+	bool unmap_success;
 	int kill = 1, forcekill;
 	struct page *hpage = *hpagep;
 	bool mlocked = PageMlocked(hpage);
@@ -1319,7 +1332,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
 		collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
 
 	if (!PageHuge(hpage)) {
-		unmap_success = try_to_unmap(hpage, ttu);
+		try_to_unmap(hpage, ttu);
 	} else {
 		if (!PageAnon(hpage)) {
 			/*
@@ -1327,21 +1340,20 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
 			 * could potentially call huge_pmd_unshare.  Because of
 			 * this, take semaphore in write mode here and set
 			 * TTU_RMAP_LOCKED to indicate we have taken the lock
-			 * at this higer level.
+			 * at this higher level.
 			 */
 			mapping = hugetlb_page_mapping_lock_write(hpage);
 			if (mapping) {
-				unmap_success = try_to_unmap(hpage,
-						     ttu|TTU_RMAP_LOCKED);
+				try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
 				i_mmap_unlock_write(mapping);
-			} else {
+			} else
 				pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
-				unmap_success = false;
-			}
 		} else {
-			unmap_success = try_to_unmap(hpage, ttu);
+			try_to_unmap(hpage, ttu);
 		}
 	}
+
+	unmap_success = !page_mapped(hpage);
 	if (!unmap_success)
 		pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
 		       pfn, page_mapcount(hpage));
@@ -1446,7 +1458,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags)
 			}
 			unlock_page(head);
 			res = MF_FAILED;
-			if (!dissolve_free_huge_page(p) && take_page_off_buddy(p)) {
+			if (__page_handle_poison(p)) {
 				page_ref_inc(p);
 				res = MF_RECOVERED;
 			}
diff --git a/mm/memory.c b/mm/memory.c
index 48c4576df898..747a01d495f2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -699,6 +699,68 @@ out:
 }
 #endif
 
+static void restore_exclusive_pte(struct vm_area_struct *vma,
+				  struct page *page, unsigned long address,
+				  pte_t *ptep)
+{
+	pte_t pte;
+	swp_entry_t entry;
+
+	pte = pte_mkold(mk_pte(page, READ_ONCE(vma->vm_page_prot)));
+	if (pte_swp_soft_dirty(*ptep))
+		pte = pte_mksoft_dirty(pte);
+
+	entry = pte_to_swp_entry(*ptep);
+	if (pte_swp_uffd_wp(*ptep))
+		pte = pte_mkuffd_wp(pte);
+	else if (is_writable_device_exclusive_entry(entry))
+		pte = maybe_mkwrite(pte_mkdirty(pte), vma);
+
+	set_pte_at(vma->vm_mm, address, ptep, pte);
+
+	/*
+	 * No need to take a page reference as one was already
+	 * created when the swap entry was made.
+	 */
+	if (PageAnon(page))
+		page_add_anon_rmap(page, vma, address, false);
+	else
+		/*
+		 * Currently device exclusive access only supports anonymous
+		 * memory so the entry shouldn't point to a filebacked page.
+		 */
+		WARN_ON_ONCE(!PageAnon(page));
+
+	if (vma->vm_flags & VM_LOCKED)
+		mlock_vma_page(page);
+
+	/*
+	 * No need to invalidate - it was non-present before. However
+	 * secondary CPUs may have mappings that need invalidating.
+	 */
+	update_mmu_cache(vma, address, ptep);
+}
+
+/*
+ * Tries to restore an exclusive pte if the page lock can be acquired without
+ * sleeping.
+ */
+static int
+try_restore_exclusive_pte(pte_t *src_pte, struct vm_area_struct *vma,
+			unsigned long addr)
+{
+	swp_entry_t entry = pte_to_swp_entry(*src_pte);
+	struct page *page = pfn_swap_entry_to_page(entry);
+
+	if (trylock_page(page)) {
+		restore_exclusive_pte(vma, page, addr, src_pte);
+		unlock_page(page);
+		return 0;
+	}
+
+	return -EBUSY;
+}
+
 /*
  * copy one vm_area from one task to the other. Assumes the page tables
  * already present in the new task to be cleared in the whole range
@@ -707,17 +769,17 @@ out:
 
 static unsigned long
 copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
-		pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
-		unsigned long addr, int *rss)
+		pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *dst_vma,
+		struct vm_area_struct *src_vma, unsigned long addr, int *rss)
 {
-	unsigned long vm_flags = vma->vm_flags;
+	unsigned long vm_flags = dst_vma->vm_flags;
 	pte_t pte = *src_pte;
 	struct page *page;
 	swp_entry_t entry = pte_to_swp_entry(pte);
 
 	if (likely(!non_swap_entry(entry))) {
 		if (swap_duplicate(entry) < 0)
-			return entry.val;
+			return -EIO;
 
 		/* make sure dst_mm is on swapoff's mmlist. */
 		if (unlikely(list_empty(&dst_mm->mmlist))) {
@@ -729,17 +791,18 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		}
 		rss[MM_SWAPENTS]++;
 	} else if (is_migration_entry(entry)) {
-		page = migration_entry_to_page(entry);
+		page = pfn_swap_entry_to_page(entry);
 
 		rss[mm_counter(page)]++;
 
-		if (is_write_migration_entry(entry) &&
+		if (is_writable_migration_entry(entry) &&
 				is_cow_mapping(vm_flags)) {
 			/*
 			 * COW mappings require pages in both
 			 * parent and child to be set to read.
 			 */
-			make_migration_entry_read(&entry);
+			entry = make_readable_migration_entry(
+							swp_offset(entry));
 			pte = swp_entry_to_pte(entry);
 			if (pte_swp_soft_dirty(*src_pte))
 				pte = pte_swp_mksoft_dirty(pte);
@@ -748,7 +811,7 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 			set_pte_at(src_mm, addr, src_pte, pte);
 		}
 	} else if (is_device_private_entry(entry)) {
-		page = device_private_entry_to_page(entry);
+		page = pfn_swap_entry_to_page(entry);
 
 		/*
 		 * Update rss count even for unaddressable pages, as
@@ -770,15 +833,29 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		 * when a device driver is involved (you cannot easily
 		 * save and restore device driver state).
 		 */
-		if (is_write_device_private_entry(entry) &&
+		if (is_writable_device_private_entry(entry) &&
 		    is_cow_mapping(vm_flags)) {
-			make_device_private_entry_read(&entry);
+			entry = make_readable_device_private_entry(
+							swp_offset(entry));
 			pte = swp_entry_to_pte(entry);
 			if (pte_swp_uffd_wp(*src_pte))
 				pte = pte_swp_mkuffd_wp(pte);
 			set_pte_at(src_mm, addr, src_pte, pte);
 		}
+	} else if (is_device_exclusive_entry(entry)) {
+		/*
+		 * Make device exclusive entries present by restoring the
+		 * original entry then copying as for a present pte. Device
+		 * exclusive entries currently only support private writable
+		 * (ie. COW) mappings.
+		 */
+		VM_BUG_ON(!is_cow_mapping(src_vma->vm_flags));
+		if (try_restore_exclusive_pte(src_pte, src_vma, addr))
+			return -EBUSY;
+		return -ENOENT;
 	}
+	if (!userfaultfd_wp(dst_vma))
+		pte = pte_swp_clear_uffd_wp(pte);
 	set_pte_at(dst_mm, addr, dst_pte, pte);
 	return 0;
 }
@@ -844,6 +921,9 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma
 	/* All done, just insert the new page copy in the child */
 	pte = mk_pte(new_page, dst_vma->vm_page_prot);
 	pte = maybe_mkwrite(pte_mkdirty(pte), dst_vma);
+	if (userfaultfd_pte_wp(dst_vma, *src_pte))
+		/* Uffd-wp needs to be delivered to dest pte as well */
+		pte = pte_wrprotect(pte_mkuffd_wp(pte));
 	set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
 	return 0;
 }
@@ -893,12 +973,7 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
 		pte = pte_mkclean(pte);
 	pte = pte_mkold(pte);
 
-	/*
-	 * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA
-	 * does not have the VM_UFFD_WP, which means that the uffd
-	 * fork event is not enabled.
-	 */
-	if (!(vm_flags & VM_UFFD_WP))
+	if (!userfaultfd_wp(dst_vma))
 		pte = pte_clear_uffd_wp(pte);
 
 	set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
@@ -971,13 +1046,25 @@ again:
 			continue;
 		}
 		if (unlikely(!pte_present(*src_pte))) {
-			entry.val = copy_nonpresent_pte(dst_mm, src_mm,
-							dst_pte, src_pte,
-							src_vma, addr, rss);
-			if (entry.val)
+			ret = copy_nonpresent_pte(dst_mm, src_mm,
+						  dst_pte, src_pte,
+						  dst_vma, src_vma,
+						  addr, rss);
+			if (ret == -EIO) {
+				entry = pte_to_swp_entry(*src_pte);
 				break;
-			progress += 8;
-			continue;
+			} else if (ret == -EBUSY) {
+				break;
+			} else if (!ret) {
+				progress += 8;
+				continue;
+			}
+
+			/*
+			 * Device exclusive entry restored, continue by copying
+			 * the now present pte.
+			 */
+			WARN_ON_ONCE(ret != -ENOENT);
 		}
 		/* copy_present_pte() will clear `*prealloc' if consumed */
 		ret = copy_present_pte(dst_vma, src_vma, dst_pte, src_pte,
@@ -1008,20 +1095,26 @@ again:
 	pte_unmap_unlock(orig_dst_pte, dst_ptl);
 	cond_resched();
 
-	if (entry.val) {
+	if (ret == -EIO) {
+		VM_WARN_ON_ONCE(!entry.val);
 		if (add_swap_count_continuation(entry, GFP_KERNEL) < 0) {
 			ret = -ENOMEM;
 			goto out;
 		}
 		entry.val = 0;
-	} else if (ret) {
-		WARN_ON_ONCE(ret != -EAGAIN);
+	} else if (ret == -EBUSY) {
+		goto out;
+	} else if (ret ==  -EAGAIN) {
 		prealloc = page_copy_prealloc(src_mm, src_vma, addr);
 		if (!prealloc)
 			return -ENOMEM;
-		/* We've captured and resolved the error. Reset, try again. */
-		ret = 0;
+	} else if (ret) {
+		VM_WARN_ON_ONCE(1);
 	}
+
+	/* We've captured and resolved the error. Reset, try again. */
+	ret = 0;
+
 	if (addr != end)
 		goto again;
 out:
@@ -1050,8 +1143,8 @@ copy_pmd_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
 			|| pmd_devmap(*src_pmd)) {
 			int err;
 			VM_BUG_ON_VMA(next-addr != HPAGE_PMD_SIZE, src_vma);
-			err = copy_huge_pmd(dst_mm, src_mm,
-					    dst_pmd, src_pmd, addr, src_vma);
+			err = copy_huge_pmd(dst_mm, src_mm, dst_pmd, src_pmd,
+					    addr, dst_vma, src_vma);
 			if (err == -ENOMEM)
 				return -ENOMEM;
 			if (!err)
@@ -1278,8 +1371,9 @@ again:
 		}
 
 		entry = pte_to_swp_entry(ptent);
-		if (is_device_private_entry(entry)) {
-			struct page *page = device_private_entry_to_page(entry);
+		if (is_device_private_entry(entry) ||
+		    is_device_exclusive_entry(entry)) {
+			struct page *page = pfn_swap_entry_to_page(entry);
 
 			if (unlikely(details && details->check_mapping)) {
 				/*
@@ -1294,7 +1388,10 @@ again:
 
 			pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
 			rss[mm_counter(page)]--;
-			page_remove_rmap(page, false);
+
+			if (is_device_private_entry(entry))
+				page_remove_rmap(page, false);
+
 			put_page(page);
 			continue;
 		}
@@ -1308,7 +1405,7 @@ again:
 		else if (is_migration_entry(entry)) {
 			struct page *page;
 
-			page = migration_entry_to_page(entry);
+			page = pfn_swap_entry_to_page(entry);
 			rss[mm_counter(page)]--;
 		}
 		if (unlikely(!free_swap_and_cache(entry)))
@@ -3343,6 +3440,34 @@ void unmap_mapping_range(struct address_space *mapping,
 EXPORT_SYMBOL(unmap_mapping_range);
 
 /*
+ * Restore a potential device exclusive pte to a working pte entry
+ */
+static vm_fault_t remove_device_exclusive_entry(struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	struct vm_area_struct *vma = vmf->vma;
+	struct mmu_notifier_range range;
+
+	if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags))
+		return VM_FAULT_RETRY;
+	mmu_notifier_range_init_owner(&range, MMU_NOTIFY_EXCLUSIVE, 0, vma,
+				vma->vm_mm, vmf->address & PAGE_MASK,
+				(vmf->address & PAGE_MASK) + PAGE_SIZE, NULL);
+	mmu_notifier_invalidate_range_start(&range);
+
+	vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
+				&vmf->ptl);
+	if (likely(pte_same(*vmf->pte, vmf->orig_pte)))
+		restore_exclusive_pte(vma, page, vmf->address, vmf->pte);
+
+	pte_unmap_unlock(vmf->pte, vmf->ptl);
+	unlock_page(page);
+
+	mmu_notifier_invalidate_range_end(&range);
+	return 0;
+}
+
+/*
  * We enter with non-exclusive mmap_lock (to exclude vma changes,
  * but allow concurrent faults), and pte mapped but not yet locked.
  * We return with pte unmapped and unlocked.
@@ -3370,8 +3495,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 		if (is_migration_entry(entry)) {
 			migration_entry_wait(vma->vm_mm, vmf->pmd,
 					     vmf->address);
+		} else if (is_device_exclusive_entry(entry)) {
+			vmf->page = pfn_swap_entry_to_page(entry);
+			ret = remove_device_exclusive_entry(vmf);
 		} else if (is_device_private_entry(entry)) {
-			vmf->page = device_private_entry_to_page(entry);
+			vmf->page = pfn_swap_entry_to_page(entry);
 			ret = vmf->page->pgmap->ops->migrate_to_ram(vmf);
 		} else if (is_hwpoison_entry(entry)) {
 			ret = VM_FAULT_HWPOISON;
@@ -4025,9 +4153,11 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf)
 	 * something).
 	 */
 	if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) {
-		ret = do_fault_around(vmf);
-		if (ret)
-			return ret;
+		if (likely(!userfaultfd_minor(vmf->vma))) {
+			ret = do_fault_around(vmf);
+			if (ret)
+				return ret;
+		}
 	}
 
 	ret = __do_fault(vmf);
@@ -4172,9 +4302,8 @@ static vm_fault_t do_fault(struct vm_fault *vmf)
 	return ret;
 }
 
-static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
-				unsigned long addr, int page_nid,
-				int *flags)
+int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
+		      unsigned long addr, int page_nid, int *flags)
 {
 	get_page(page);
 
@@ -4295,12 +4424,12 @@ static inline vm_fault_t create_huge_pmd(struct vm_fault *vmf)
 }
 
 /* `inline' is required to avoid gcc 4.1.2 build error */
-static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
+static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf)
 {
 	if (vma_is_anonymous(vmf->vma)) {
-		if (userfaultfd_huge_pmd_wp(vmf->vma, orig_pmd))
+		if (userfaultfd_huge_pmd_wp(vmf->vma, vmf->orig_pmd))
 			return handle_userfault(vmf, VM_UFFD_WP);
-		return do_huge_pmd_wp_page(vmf, orig_pmd);
+		return do_huge_pmd_wp_page(vmf);
 	}
 	if (vmf->vma->vm_ops->huge_fault) {
 		vm_fault_t ret = vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD);
@@ -4527,26 +4656,26 @@ retry_pud:
 		if (!(ret & VM_FAULT_FALLBACK))
 			return ret;
 	} else {
-		pmd_t orig_pmd = *vmf.pmd;
+		vmf.orig_pmd = *vmf.pmd;
 
 		barrier();
-		if (unlikely(is_swap_pmd(orig_pmd))) {
+		if (unlikely(is_swap_pmd(vmf.orig_pmd))) {
 			VM_BUG_ON(thp_migration_supported() &&
-					  !is_pmd_migration_entry(orig_pmd));
-			if (is_pmd_migration_entry(orig_pmd))
+					  !is_pmd_migration_entry(vmf.orig_pmd));
+			if (is_pmd_migration_entry(vmf.orig_pmd))
 				pmd_migration_entry_wait(mm, vmf.pmd);
 			return 0;
 		}
-		if (pmd_trans_huge(orig_pmd) || pmd_devmap(orig_pmd)) {
-			if (pmd_protnone(orig_pmd) && vma_is_accessible(vma))
-				return do_huge_pmd_numa_page(&vmf, orig_pmd);
+		if (pmd_trans_huge(vmf.orig_pmd) || pmd_devmap(vmf.orig_pmd)) {
+			if (pmd_protnone(vmf.orig_pmd) && vma_is_accessible(vma))
+				return do_huge_pmd_numa_page(&vmf);
 
-			if (dirty && !pmd_write(orig_pmd)) {
-				ret = wp_huge_pmd(&vmf, orig_pmd);
+			if (dirty && !pmd_write(vmf.orig_pmd)) {
+				ret = wp_huge_pmd(&vmf);
 				if (!(ret & VM_FAULT_FALLBACK))
 					return ret;
 			} else {
-				huge_pmd_set_accessed(&vmf, orig_pmd);
+				huge_pmd_set_accessed(&vmf);
 				return 0;
 			}
 		}
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 974a565797d8..8cb75b26ea4f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -154,122 +154,6 @@ static void release_memory_resource(struct resource *res)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
-void get_page_bootmem(unsigned long info,  struct page *page,
-		      unsigned long type)
-{
-	page->freelist = (void *)type;
-	SetPagePrivate(page);
-	set_page_private(page, info);
-	page_ref_inc(page);
-}
-
-void put_page_bootmem(struct page *page)
-{
-	unsigned long type;
-
-	type = (unsigned long) page->freelist;
-	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
-	       type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
-
-	if (page_ref_dec_return(page) == 1) {
-		page->freelist = NULL;
-		ClearPagePrivate(page);
-		set_page_private(page, 0);
-		INIT_LIST_HEAD(&page->lru);
-		free_reserved_page(page);
-	}
-}
-
-#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
-static void register_page_bootmem_info_section(unsigned long start_pfn)
-{
-	unsigned long mapsize, section_nr, i;
-	struct mem_section *ms;
-	struct page *page, *memmap;
-	struct mem_section_usage *usage;
-
-	section_nr = pfn_to_section_nr(start_pfn);
-	ms = __nr_to_section(section_nr);
-
-	/* Get section's memmap address */
-	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
-
-	/*
-	 * Get page for the memmap's phys address
-	 * XXX: need more consideration for sparse_vmemmap...
-	 */
-	page = virt_to_page(memmap);
-	mapsize = sizeof(struct page) * PAGES_PER_SECTION;
-	mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
-
-	/* remember memmap's page */
-	for (i = 0; i < mapsize; i++, page++)
-		get_page_bootmem(section_nr, page, SECTION_INFO);
-
-	usage = ms->usage;
-	page = virt_to_page(usage);
-
-	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
-
-	for (i = 0; i < mapsize; i++, page++)
-		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
-
-}
-#else /* CONFIG_SPARSEMEM_VMEMMAP */
-static void register_page_bootmem_info_section(unsigned long start_pfn)
-{
-	unsigned long mapsize, section_nr, i;
-	struct mem_section *ms;
-	struct page *page, *memmap;
-	struct mem_section_usage *usage;
-
-	section_nr = pfn_to_section_nr(start_pfn);
-	ms = __nr_to_section(section_nr);
-
-	memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
-
-	register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
-
-	usage = ms->usage;
-	page = virt_to_page(usage);
-
-	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
-
-	for (i = 0; i < mapsize; i++, page++)
-		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
-}
-#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
-
-void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
-{
-	unsigned long i, pfn, end_pfn, nr_pages;
-	int node = pgdat->node_id;
-	struct page *page;
-
-	nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
-	page = virt_to_page(pgdat);
-
-	for (i = 0; i < nr_pages; i++, page++)
-		get_page_bootmem(node, page, NODE_INFO);
-
-	pfn = pgdat->node_start_pfn;
-	end_pfn = pgdat_end_pfn(pgdat);
-
-	/* register section info */
-	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
-		/*
-		 * Some platforms can assign the same pfn to multiple nodes - on
-		 * node0 as well as nodeN.  To avoid registering a pfn against
-		 * multiple nodes we check that this pfn does not already
-		 * reside in some other nodes.
-		 */
-		if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
-			register_page_bootmem_info_section(pfn);
-	}
-}
-#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
-
 static int check_pfn_span(unsigned long pfn, unsigned long nr_pages,
 		const char *reason)
 {
@@ -445,7 +329,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
 	unsigned long pfn;
 	int nid = zone_to_nid(zone);
 
-	zone_span_writelock(zone);
 	if (zone->zone_start_pfn == start_pfn) {
 		/*
 		 * If the section is smallest section in the zone, it need
@@ -478,7 +361,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
 			zone->spanned_pages = 0;
 		}
 	}
-	zone_span_writeunlock(zone);
 }
 
 static void update_pgdat_span(struct pglist_data *pgdat)
@@ -515,7 +397,7 @@ void __ref remove_pfn_range_from_zone(struct zone *zone,
 {
 	const unsigned long end_pfn = start_pfn + nr_pages;
 	struct pglist_data *pgdat = zone->zone_pgdat;
-	unsigned long pfn, cur_nr_pages, flags;
+	unsigned long pfn, cur_nr_pages;
 
 	/* Poison struct pages because they are now uninitialized again. */
 	for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) {
@@ -540,10 +422,8 @@ void __ref remove_pfn_range_from_zone(struct zone *zone,
 
 	clear_zone_contiguous(zone);
 
-	pgdat_resize_lock(zone->zone_pgdat, &flags);
 	shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
 	update_pgdat_span(pgdat);
-	pgdat_resize_unlock(zone->zone_pgdat, &flags);
 
 	set_zone_contiguous(zone);
 }
@@ -750,19 +630,13 @@ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 {
 	struct pglist_data *pgdat = zone->zone_pgdat;
 	int nid = pgdat->node_id;
-	unsigned long flags;
 
 	clear_zone_contiguous(zone);
 
-	/* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
-	pgdat_resize_lock(pgdat, &flags);
-	zone_span_writelock(zone);
 	if (zone_is_empty(zone))
 		init_currently_empty_zone(zone, start_pfn, nr_pages);
 	resize_zone_range(zone, start_pfn, nr_pages);
-	zone_span_writeunlock(zone);
 	resize_pgdat_range(pgdat, start_pfn, nr_pages);
-	pgdat_resize_unlock(pgdat, &flags);
 
 	/*
 	 * Subsection population requires care in pfn_to_online_page().
@@ -852,12 +726,8 @@ struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
  */
 void adjust_present_page_count(struct zone *zone, long nr_pages)
 {
-	unsigned long flags;
-
 	zone->present_pages += nr_pages;
-	pgdat_resize_lock(zone->zone_pgdat, &flags);
 	zone->zone_pgdat->node_present_pages += nr_pages;
-	pgdat_resize_unlock(zone->zone_pgdat, &flags);
 }
 
 int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
@@ -913,7 +783,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, struct zone *z
 
 	/*
 	 * {on,off}lining is constrained to full memory sections (or more
-	 * precisly to memory blocks from the user space POV).
+	 * precisely to memory blocks from the user space POV).
 	 * memmap_on_memory is an exception because it reserves initial part
 	 * of the physical memory space for vmemmaps. That space is pageblock
 	 * aligned.
@@ -1072,8 +942,8 @@ static void rollback_node_hotadd(int nid)
 }
 
 
-/**
- * try_online_node - online a node if offlined
+/*
+ * __try_online_node - online a node if offlined
  * @nid: the node ID
  * @set_node_online: Whether we want to online the node
  * called by cpu_up() to online a node without onlined memory.
@@ -1172,6 +1042,7 @@ bool mhp_supports_memmap_on_memory(unsigned long size)
 	 *       populate a single PMD.
 	 */
 	return memmap_on_memory &&
+	       !hugetlb_free_vmemmap_enabled &&
 	       IS_ENABLED(CONFIG_MHP_MEMMAP_ON_MEMORY) &&
 	       size == memory_block_size_bytes() &&
 	       IS_ALIGNED(vmemmap_size, PMD_SIZE) &&
@@ -1521,6 +1392,8 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 	struct page *page, *head;
 	int ret = 0;
 	LIST_HEAD(source);
+	static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,
+				      DEFAULT_RATELIMIT_BURST);
 
 	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
 		if (!pfn_valid(pfn))
@@ -1567,8 +1440,10 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 						    page_is_file_lru(page));
 
 		} else {
-			pr_warn("failed to isolate pfn %lx\n", pfn);
-			dump_page(page, "isolation failed");
+			if (__ratelimit(&migrate_rs)) {
+				pr_warn("failed to isolate pfn %lx\n", pfn);
+				dump_page(page, "isolation failed");
+			}
 		}
 		put_page(page);
 	}
@@ -1597,9 +1472,11 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
 		if (ret) {
 			list_for_each_entry(page, &source, lru) {
-				pr_warn("migrating pfn %lx failed ret:%d ",
-				       page_to_pfn(page), ret);
-				dump_page(page, "migration failure");
+				if (__ratelimit(&migrate_rs)) {
+					pr_warn("migrating pfn %lx failed ret:%d\n",
+						page_to_pfn(page), ret);
+					dump_page(page, "migration failure");
+				}
 			}
 			putback_movable_pages(&source);
 		}
@@ -1703,7 +1580,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
 
 	/*
 	 * {on,off}lining is constrained to full memory sections (or more
-	 * precisly to memory blocks from the user space POV).
+	 * precisely to memory blocks from the user space POV).
 	 * memmap_on_memory is an exception because it reserves initial part
 	 * of the physical memory space for vmemmaps. That space is pageblock
 	 * aligned.
@@ -2031,7 +1908,7 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size)
 }
 
 /**
- * remove_memory
+ * __remove_memory - Remove memory if every memory block is offline
  * @nid: the node ID
  * @start: physical address of the region to remove
  * @size: size of the region to remove
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b5d95bf1025d..e32360e90274 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -121,8 +121,7 @@ enum zone_type policy_zone = 0;
  */
 static struct mempolicy default_policy = {
 	.refcnt = ATOMIC_INIT(1), /* never free it */
-	.mode = MPOL_PREFERRED,
-	.flags = MPOL_F_LOCAL,
+	.mode = MPOL_LOCAL,
 };
 
 static struct mempolicy preferred_node_policy[MAX_NUMNODES];
@@ -194,18 +193,17 @@ static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
 {
 	if (nodes_empty(*nodes))
 		return -EINVAL;
-	pol->v.nodes = *nodes;
+	pol->nodes = *nodes;
 	return 0;
 }
 
 static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
 {
-	if (!nodes)
-		pol->flags |= MPOL_F_LOCAL;	/* local allocation */
-	else if (nodes_empty(*nodes))
-		return -EINVAL;			/*  no allowed nodes */
-	else
-		pol->v.preferred_node = first_node(*nodes);
+	if (nodes_empty(*nodes))
+		return -EINVAL;
+
+	nodes_clear(pol->nodes);
+	node_set(first_node(*nodes), pol->nodes);
 	return 0;
 }
 
@@ -213,15 +211,14 @@ static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
 {
 	if (nodes_empty(*nodes))
 		return -EINVAL;
-	pol->v.nodes = *nodes;
+	pol->nodes = *nodes;
 	return 0;
 }
 
 /*
  * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
  * any, for the new policy.  mpol_new() has already validated the nodes
- * parameter with respect to the policy mode and flags.  But, we need to
- * handle an empty nodemask with MPOL_PREFERRED here.
+ * parameter with respect to the policy mode and flags.
  *
  * Must be called holding task's alloc_lock to protect task's mems_allowed
  * and mempolicy.  May also be called holding the mmap_lock for write.
@@ -231,33 +228,31 @@ static int mpol_set_nodemask(struct mempolicy *pol,
 {
 	int ret;
 
-	/* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
-	if (pol == NULL)
+	/*
+	 * Default (pol==NULL) resp. local memory policies are not a
+	 * subject of any remapping. They also do not need any special
+	 * constructor.
+	 */
+	if (!pol || pol->mode == MPOL_LOCAL)
 		return 0;
+
 	/* Check N_MEMORY */
 	nodes_and(nsc->mask1,
 		  cpuset_current_mems_allowed, node_states[N_MEMORY]);
 
 	VM_BUG_ON(!nodes);
-	if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
-		nodes = NULL;	/* explicit local allocation */
-	else {
-		if (pol->flags & MPOL_F_RELATIVE_NODES)
-			mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
-		else
-			nodes_and(nsc->mask2, *nodes, nsc->mask1);
 
-		if (mpol_store_user_nodemask(pol))
-			pol->w.user_nodemask = *nodes;
-		else
-			pol->w.cpuset_mems_allowed =
-						cpuset_current_mems_allowed;
-	}
+	if (pol->flags & MPOL_F_RELATIVE_NODES)
+		mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
+	else
+		nodes_and(nsc->mask2, *nodes, nsc->mask1);
 
-	if (nodes)
-		ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
+	if (mpol_store_user_nodemask(pol))
+		pol->w.user_nodemask = *nodes;
 	else
-		ret = mpol_ops[pol->mode].create(pol, NULL);
+		pol->w.cpuset_mems_allowed = cpuset_current_mems_allowed;
+
+	ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
 	return ret;
 }
 
@@ -290,13 +285,14 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
 			if (((flags & MPOL_F_STATIC_NODES) ||
 			     (flags & MPOL_F_RELATIVE_NODES)))
 				return ERR_PTR(-EINVAL);
+
+			mode = MPOL_LOCAL;
 		}
 	} else if (mode == MPOL_LOCAL) {
 		if (!nodes_empty(*nodes) ||
 		    (flags & MPOL_F_STATIC_NODES) ||
 		    (flags & MPOL_F_RELATIVE_NODES))
 			return ERR_PTR(-EINVAL);
-		mode = MPOL_PREFERRED;
 	} else if (nodes_empty(*nodes))
 		return ERR_PTR(-EINVAL);
 	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
@@ -330,7 +326,7 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
 	else if (pol->flags & MPOL_F_RELATIVE_NODES)
 		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
 	else {
-		nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed,
+		nodes_remap(tmp, pol->nodes, pol->w.cpuset_mems_allowed,
 								*nodes);
 		pol->w.cpuset_mems_allowed = *nodes;
 	}
@@ -338,31 +334,13 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
 	if (nodes_empty(tmp))
 		tmp = *nodes;
 
-	pol->v.nodes = tmp;
+	pol->nodes = tmp;
 }
 
 static void mpol_rebind_preferred(struct mempolicy *pol,
 						const nodemask_t *nodes)
 {
-	nodemask_t tmp;
-
-	if (pol->flags & MPOL_F_STATIC_NODES) {
-		int node = first_node(pol->w.user_nodemask);
-
-		if (node_isset(node, *nodes)) {
-			pol->v.preferred_node = node;
-			pol->flags &= ~MPOL_F_LOCAL;
-		} else
-			pol->flags |= MPOL_F_LOCAL;
-	} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
-		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
-		pol->v.preferred_node = first_node(tmp);
-	} else if (!(pol->flags & MPOL_F_LOCAL)) {
-		pol->v.preferred_node = node_remap(pol->v.preferred_node,
-						   pol->w.cpuset_mems_allowed,
-						   *nodes);
-		pol->w.cpuset_mems_allowed = *nodes;
-	}
+	pol->w.cpuset_mems_allowed = *nodes;
 }
 
 /*
@@ -376,7 +354,7 @@ static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
 {
 	if (!pol)
 		return;
-	if (!mpol_store_user_nodemask(pol) && !(pol->flags & MPOL_F_LOCAL) &&
+	if (!mpol_store_user_nodemask(pol) &&
 	    nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
 		return;
 
@@ -427,6 +405,9 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
 		.create = mpol_new_bind,
 		.rebind = mpol_rebind_nodemask,
 	},
+	[MPOL_LOCAL] = {
+		.rebind = mpol_rebind_default,
+	},
 };
 
 static int migrate_page_add(struct page *page, struct list_head *pagelist,
@@ -458,7 +439,8 @@ static inline bool queue_pages_required(struct page *page,
 
 /*
  * queue_pages_pmd() has four possible return values:
- * 0 - pages are placed on the right node or queued successfully.
+ * 0 - pages are placed on the right node or queued successfully, or
+ *     special page is met, i.e. huge zero page.
  * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
  *     specified.
  * 2 - THP was split.
@@ -482,8 +464,7 @@ static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
 	page = pmd_page(*pmd);
 	if (is_huge_zero_page(page)) {
 		spin_unlock(ptl);
-		__split_huge_pmd(walk->vma, pmd, addr, false, NULL);
-		ret = 2;
+		walk->action = ACTION_CONTINUE;
 		goto out;
 	}
 	if (!queue_pages_required(page, qp))
@@ -510,7 +491,8 @@ out:
  * and move them to the pagelist if they do.
  *
  * queue_pages_pte_range() has three possible return values:
- * 0 - pages are placed on the right node or queued successfully.
+ * 0 - pages are placed on the right node or queued successfully, or
+ *     special page is met, i.e. zero page.
  * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
  *     specified.
  * -EIO - only MPOL_MF_STRICT was specified and an existing page was already
@@ -917,12 +899,11 @@ static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
 	switch (p->mode) {
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		*nodes = p->v.nodes;
-		break;
 	case MPOL_PREFERRED:
-		if (!(p->flags & MPOL_F_LOCAL))
-			node_set(p->v.preferred_node, *nodes);
-		/* else return empty node mask for local allocation */
+		*nodes = p->nodes;
+		break;
+	case MPOL_LOCAL:
+		/* return empty node mask for local allocation */
 		break;
 	default:
 		BUG();
@@ -1007,7 +988,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 			*policy = err;
 		} else if (pol == current->mempolicy &&
 				pol->mode == MPOL_INTERLEAVE) {
-			*policy = next_node_in(current->il_prev, pol->v.nodes);
+			*policy = next_node_in(current->il_prev, pol->nodes);
 		} else {
 			err = -EINVAL;
 			goto out;
@@ -1460,26 +1441,38 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
 	return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
 }
 
+/* Basic parameter sanity check used by both mbind() and set_mempolicy() */
+static inline int sanitize_mpol_flags(int *mode, unsigned short *flags)
+{
+	*flags = *mode & MPOL_MODE_FLAGS;
+	*mode &= ~MPOL_MODE_FLAGS;
+	if ((unsigned int)(*mode) >= MPOL_MAX)
+		return -EINVAL;
+	if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES))
+		return -EINVAL;
+
+	return 0;
+}
+
 static long kernel_mbind(unsigned long start, unsigned long len,
 			 unsigned long mode, const unsigned long __user *nmask,
 			 unsigned long maxnode, unsigned int flags)
 {
+	unsigned short mode_flags;
 	nodemask_t nodes;
+	int lmode = mode;
 	int err;
-	unsigned short mode_flags;
 
 	start = untagged_addr(start);
-	mode_flags = mode & MPOL_MODE_FLAGS;
-	mode &= ~MPOL_MODE_FLAGS;
-	if (mode >= MPOL_MAX)
-		return -EINVAL;
-	if ((mode_flags & MPOL_F_STATIC_NODES) &&
-	    (mode_flags & MPOL_F_RELATIVE_NODES))
-		return -EINVAL;
+	err = sanitize_mpol_flags(&lmode, &mode_flags);
+	if (err)
+		return err;
+
 	err = get_nodes(&nodes, nmask, maxnode);
 	if (err)
 		return err;
-	return do_mbind(start, len, mode, mode_flags, &nodes, flags);
+
+	return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
 }
 
 SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
@@ -1493,20 +1486,20 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
 static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 				 unsigned long maxnode)
 {
-	int err;
+	unsigned short mode_flags;
 	nodemask_t nodes;
-	unsigned short flags;
+	int lmode = mode;
+	int err;
+
+	err = sanitize_mpol_flags(&lmode, &mode_flags);
+	if (err)
+		return err;
 
-	flags = mode & MPOL_MODE_FLAGS;
-	mode &= ~MPOL_MODE_FLAGS;
-	if ((unsigned int)mode >= MPOL_MAX)
-		return -EINVAL;
-	if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
-		return -EINVAL;
 	err = get_nodes(&nodes, nmask, maxnode);
 	if (err)
 		return err;
-	return do_set_mempolicy(mode, flags, &nodes);
+
+	return do_set_mempolicy(lmode, mode_flags, &nodes);
 }
 
 SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
@@ -1863,14 +1856,14 @@ static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
 	BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
 
 	/*
-	 * if policy->v.nodes has movable memory only,
+	 * if policy->nodes has movable memory only,
 	 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
 	 *
-	 * policy->v.nodes is intersect with node_states[N_MEMORY].
+	 * policy->nodes is intersect with node_states[N_MEMORY].
 	 * so if the following test fails, it implies
-	 * policy->v.nodes has movable memory only.
+	 * policy->nodes has movable memory only.
 	 */
-	if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
+	if (!nodes_intersects(policy->nodes, node_states[N_HIGH_MEMORY]))
 		dynamic_policy_zone = ZONE_MOVABLE;
 
 	return zone >= dynamic_policy_zone;
@@ -1885,8 +1878,8 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
 	/* Lower zones don't get a nodemask applied for MPOL_BIND */
 	if (unlikely(policy->mode == MPOL_BIND) &&
 			apply_policy_zone(policy, gfp_zone(gfp)) &&
-			cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
-		return &policy->v.nodes;
+			cpuset_nodemask_valid_mems_allowed(&policy->nodes))
+		return &policy->nodes;
 
 	return NULL;
 }
@@ -1894,9 +1887,9 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
 /* Return the node id preferred by the given mempolicy, or the given id */
 static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd)
 {
-	if (policy->mode == MPOL_PREFERRED && !(policy->flags & MPOL_F_LOCAL))
-		nd = policy->v.preferred_node;
-	else {
+	if (policy->mode == MPOL_PREFERRED) {
+		nd = first_node(policy->nodes);
+	} else {
 		/*
 		 * __GFP_THISNODE shouldn't even be used with the bind policy
 		 * because we might easily break the expectation to stay on the
@@ -1914,7 +1907,7 @@ static unsigned interleave_nodes(struct mempolicy *policy)
 	unsigned next;
 	struct task_struct *me = current;
 
-	next = next_node_in(me->il_prev, policy->v.nodes);
+	next = next_node_in(me->il_prev, policy->nodes);
 	if (next < MAX_NUMNODES)
 		me->il_prev = next;
 	return next;
@@ -1933,15 +1926,12 @@ unsigned int mempolicy_slab_node(void)
 		return node;
 
 	policy = current->mempolicy;
-	if (!policy || policy->flags & MPOL_F_LOCAL)
+	if (!policy)
 		return node;
 
 	switch (policy->mode) {
 	case MPOL_PREFERRED:
-		/*
-		 * handled MPOL_F_LOCAL above
-		 */
-		return policy->v.preferred_node;
+		return first_node(policy->nodes);
 
 	case MPOL_INTERLEAVE:
 		return interleave_nodes(policy);
@@ -1957,9 +1947,11 @@ unsigned int mempolicy_slab_node(void)
 		enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
 		zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
 		z = first_zones_zonelist(zonelist, highest_zoneidx,
-							&policy->v.nodes);
+							&policy->nodes);
 		return z->zone ? zone_to_nid(z->zone) : node;
 	}
+	case MPOL_LOCAL:
+		return node;
 
 	default:
 		BUG();
@@ -1968,12 +1960,12 @@ unsigned int mempolicy_slab_node(void)
 
 /*
  * Do static interleaving for a VMA with known offset @n.  Returns the n'th
- * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the
+ * node in pol->nodes (starting from n=0), wrapping around if n exceeds the
  * number of present nodes.
  */
 static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
 {
-	unsigned nnodes = nodes_weight(pol->v.nodes);
+	unsigned nnodes = nodes_weight(pol->nodes);
 	unsigned target;
 	int i;
 	int nid;
@@ -1981,9 +1973,9 @@ static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
 	if (!nnodes)
 		return numa_node_id();
 	target = (unsigned int)n % nnodes;
-	nid = first_node(pol->v.nodes);
+	nid = first_node(pol->nodes);
 	for (i = 0; i < target; i++)
-		nid = next_node(nid, pol->v.nodes);
+		nid = next_node(nid, pol->nodes);
 	return nid;
 }
 
@@ -2039,7 +2031,7 @@ int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
 	} else {
 		nid = policy_node(gfp_flags, *mpol, numa_node_id());
 		if ((*mpol)->mode == MPOL_BIND)
-			*nodemask = &(*mpol)->v.nodes;
+			*nodemask = &(*mpol)->nodes;
 	}
 	return nid;
 }
@@ -2063,7 +2055,6 @@ int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
 bool init_nodemask_of_mempolicy(nodemask_t *mask)
 {
 	struct mempolicy *mempolicy;
-	int nid;
 
 	if (!(mask && current->mempolicy))
 		return false;
@@ -2072,16 +2063,13 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
 	mempolicy = current->mempolicy;
 	switch (mempolicy->mode) {
 	case MPOL_PREFERRED:
-		if (mempolicy->flags & MPOL_F_LOCAL)
-			nid = numa_node_id();
-		else
-			nid = mempolicy->v.preferred_node;
-		init_nodemask_of_node(mask, nid);
-		break;
-
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		*mask =  mempolicy->v.nodes;
+		*mask = mempolicy->nodes;
+		break;
+
+	case MPOL_LOCAL:
+		init_nodemask_of_node(mask, numa_node_id());
 		break;
 
 	default:
@@ -2094,16 +2082,16 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
 #endif
 
 /*
- * mempolicy_nodemask_intersects
+ * mempolicy_in_oom_domain
  *
- * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
- * policy.  Otherwise, check for intersection between mask and the policy
- * nodemask for 'bind' or 'interleave' policy.  For 'preferred' or 'local'
- * policy, always return true since it may allocate elsewhere on fallback.
+ * If tsk's mempolicy is "bind", check for intersection between mask and
+ * the policy nodemask. Otherwise, return true for all other policies
+ * including "interleave", as a tsk with "interleave" policy may have
+ * memory allocated from all nodes in system.
  *
  * Takes task_lock(tsk) to prevent freeing of its mempolicy.
  */
-bool mempolicy_nodemask_intersects(struct task_struct *tsk,
+bool mempolicy_in_oom_domain(struct task_struct *tsk,
 					const nodemask_t *mask)
 {
 	struct mempolicy *mempolicy;
@@ -2111,29 +2099,13 @@ bool mempolicy_nodemask_intersects(struct task_struct *tsk,
 
 	if (!mask)
 		return ret;
+
 	task_lock(tsk);
 	mempolicy = tsk->mempolicy;
-	if (!mempolicy)
-		goto out;
-
-	switch (mempolicy->mode) {
-	case MPOL_PREFERRED:
-		/*
-		 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
-		 * allocate from, they may fallback to other nodes when oom.
-		 * Thus, it's possible for tsk to have allocated memory from
-		 * nodes in mask.
-		 */
-		break;
-	case MPOL_BIND:
-	case MPOL_INTERLEAVE:
-		ret = nodes_intersects(mempolicy->v.nodes, *mask);
-		break;
-	default:
-		BUG();
-	}
-out:
+	if (mempolicy && mempolicy->mode == MPOL_BIND)
+		ret = nodes_intersects(mempolicy->nodes, *mask);
 	task_unlock(tsk);
+
 	return ret;
 }
 
@@ -2204,8 +2176,8 @@ struct page *alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
 		 * If the policy is interleave, or does not allow the current
 		 * node in its nodemask, we allocate the standard way.
 		 */
-		if (pol->mode == MPOL_PREFERRED && !(pol->flags & MPOL_F_LOCAL))
-			hpage_node = pol->v.preferred_node;
+		if (pol->mode == MPOL_PREFERRED)
+			hpage_node = first_node(pol->nodes);
 
 		nmask = policy_nodemask(gfp, pol);
 		if (!nmask || node_isset(hpage_node, *nmask)) {
@@ -2338,12 +2310,10 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
 	switch (a->mode) {
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		return !!nodes_equal(a->v.nodes, b->v.nodes);
 	case MPOL_PREFERRED:
-		/* a's ->flags is the same as b's */
-		if (a->flags & MPOL_F_LOCAL)
-			return true;
-		return a->v.preferred_node == b->v.preferred_node;
+		return !!nodes_equal(a->nodes, b->nodes);
+	case MPOL_LOCAL:
+		return true;
 	default:
 		BUG();
 		return false;
@@ -2481,16 +2451,17 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
 		break;
 
 	case MPOL_PREFERRED:
-		if (pol->flags & MPOL_F_LOCAL)
-			polnid = numa_node_id();
-		else
-			polnid = pol->v.preferred_node;
+		polnid = first_node(pol->nodes);
+		break;
+
+	case MPOL_LOCAL:
+		polnid = numa_node_id();
 		break;
 
 	case MPOL_BIND:
 		/* Optimize placement among multiple nodes via NUMA balancing */
 		if (pol->flags & MPOL_F_MORON) {
-			if (node_isset(thisnid, pol->v.nodes))
+			if (node_isset(thisnid, pol->nodes))
 				break;
 			goto out;
 		}
@@ -2501,12 +2472,12 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
 		 * else select nearest allowed node, if any.
 		 * If no allowed nodes, use current [!misplaced].
 		 */
-		if (node_isset(curnid, pol->v.nodes))
+		if (node_isset(curnid, pol->nodes))
 			goto out;
 		z = first_zones_zonelist(
 				node_zonelist(numa_node_id(), GFP_HIGHUSER),
 				gfp_zone(GFP_HIGHUSER),
-				&pol->v.nodes);
+				&pol->nodes);
 		polnid = zone_to_nid(z->zone);
 		break;
 
@@ -2709,7 +2680,7 @@ int mpol_set_shared_policy(struct shared_policy *info,
 		 vma->vm_pgoff,
 		 sz, npol ? npol->mode : -1,
 		 npol ? npol->flags : -1,
-		 npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
+		 npol ? nodes_addr(npol->nodes)[0] : NUMA_NO_NODE);
 
 	if (npol) {
 		new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
@@ -2807,7 +2778,7 @@ void __init numa_policy_init(void)
 			.refcnt = ATOMIC_INIT(1),
 			.mode = MPOL_PREFERRED,
 			.flags = MPOL_F_MOF | MPOL_F_MORON,
-			.v = { .preferred_node = nid, },
+			.nodes = nodemask_of_node(nid),
 		};
 	}
 
@@ -2851,9 +2822,6 @@ void numa_default_policy(void)
  * Parse and format mempolicy from/to strings
  */
 
-/*
- * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
- */
 static const char * const policy_modes[] =
 {
 	[MPOL_DEFAULT]    = "default",
@@ -2931,7 +2899,6 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 		 */
 		if (nodelist)
 			goto out;
-		mode = MPOL_PREFERRED;
 		break;
 	case MPOL_DEFAULT:
 		/*
@@ -2970,12 +2937,14 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 	 * Save nodes for mpol_to_str() to show the tmpfs mount options
 	 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
 	 */
-	if (mode != MPOL_PREFERRED)
-		new->v.nodes = nodes;
-	else if (nodelist)
-		new->v.preferred_node = first_node(nodes);
-	else
-		new->flags |= MPOL_F_LOCAL;
+	if (mode != MPOL_PREFERRED) {
+		new->nodes = nodes;
+	} else if (nodelist) {
+		nodes_clear(new->nodes);
+		node_set(first_node(nodes), new->nodes);
+	} else {
+		new->mode = MPOL_LOCAL;
+	}
 
 	/*
 	 * Save nodes for contextualization: this will be used to "clone"
@@ -3021,16 +2990,12 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
 
 	switch (mode) {
 	case MPOL_DEFAULT:
+	case MPOL_LOCAL:
 		break;
 	case MPOL_PREFERRED:
-		if (flags & MPOL_F_LOCAL)
-			mode = MPOL_LOCAL;
-		else
-			node_set(pol->v.preferred_node, nodes);
-		break;
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		nodes = pol->v.nodes;
+		nodes = pol->nodes;
 		break;
 	default:
 		WARN_ON_ONCE(1);
diff --git a/mm/migrate.c b/mm/migrate.c
index 380ca57b9031..23cbd9de030b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -210,13 +210,18 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 		 * Recheck VMA as permissions can change since migration started
 		 */
 		entry = pte_to_swp_entry(*pvmw.pte);
-		if (is_write_migration_entry(entry))
+		if (is_writable_migration_entry(entry))
 			pte = maybe_mkwrite(pte, vma);
 		else if (pte_swp_uffd_wp(*pvmw.pte))
 			pte = pte_mkuffd_wp(pte);
 
 		if (unlikely(is_device_private_page(new))) {
-			entry = make_device_private_entry(new, pte_write(pte));
+			if (pte_write(pte))
+				entry = make_writable_device_private_entry(
+							page_to_pfn(new));
+			else
+				entry = make_readable_device_private_entry(
+							page_to_pfn(new));
 			pte = swp_entry_to_pte(entry);
 			if (pte_swp_soft_dirty(*pvmw.pte))
 				pte = pte_swp_mksoft_dirty(pte);
@@ -226,8 +231,10 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 
 #ifdef CONFIG_HUGETLB_PAGE
 		if (PageHuge(new)) {
+			unsigned int shift = huge_page_shift(hstate_vma(vma));
+
 			pte = pte_mkhuge(pte);
-			pte = arch_make_huge_pte(pte, vma, new, 0);
+			pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
 			set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
 			if (PageAnon(new))
 				hugepage_add_anon_rmap(new, vma, pvmw.address);
@@ -294,7 +301,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
 	if (!is_migration_entry(entry))
 		goto out;
 
-	page = migration_entry_to_page(entry);
+	page = pfn_swap_entry_to_page(entry);
 	page = compound_head(page);
 
 	/*
@@ -335,7 +342,7 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
 	ptl = pmd_lock(mm, pmd);
 	if (!is_pmd_migration_entry(*pmd))
 		goto unlock;
-	page = migration_entry_to_page(pmd_to_swp_entry(*pmd));
+	page = pfn_swap_entry_to_page(pmd_to_swp_entry(*pmd));
 	if (!get_page_unless_zero(page))
 		goto unlock;
 	spin_unlock(ptl);
@@ -551,7 +558,7 @@ static void __copy_gigantic_page(struct page *dst, struct page *src,
 	}
 }
 
-static void copy_huge_page(struct page *dst, struct page *src)
+void copy_huge_page(struct page *dst, struct page *src)
 {
 	int i;
 	int nr_pages;
@@ -626,7 +633,10 @@ void migrate_page_states(struct page *newpage, struct page *page)
 	if (PageSwapCache(page))
 		ClearPageSwapCache(page);
 	ClearPagePrivate(page);
-	set_page_private(page, 0);
+
+	/* page->private contains hugetlb specific flags */
+	if (!PageHuge(page))
+		set_page_private(page, 0);
 
 	/*
 	 * If any waiters have accumulated on the new page then
@@ -1099,7 +1109,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 		/* Establish migration ptes */
 		VM_BUG_ON_PAGE(PageAnon(page) && !PageKsm(page) && !anon_vma,
 				page);
-		try_to_unmap(page, TTU_MIGRATION|TTU_IGNORE_MLOCK);
+		try_to_migrate(page, 0);
 		page_was_mapped = 1;
 	}
 
@@ -1288,7 +1298,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 	 * page_mapping() set, hugetlbfs specific move page routine will not
 	 * be called and we could leak usage counts for subpools.
 	 */
-	if (page_private(hpage) && !page_mapping(hpage)) {
+	if (hugetlb_page_subpool(hpage) && !page_mapping(hpage)) {
 		rc = -EBUSY;
 		goto out_unlock;
 	}
@@ -1301,7 +1311,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 
 	if (page_mapped(hpage)) {
 		bool mapping_locked = false;
-		enum ttu_flags ttu = TTU_MIGRATION|TTU_IGNORE_MLOCK;
+		enum ttu_flags ttu = 0;
 
 		if (!PageAnon(hpage)) {
 			/*
@@ -1318,7 +1328,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 			ttu |= TTU_RMAP_LOCKED;
 		}
 
-		try_to_unmap(hpage, ttu);
+		try_to_migrate(hpage, ttu);
 		page_was_mapped = 1;
 
 		if (mapping_locked)
@@ -1418,6 +1428,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 	int swapwrite = current->flags & PF_SWAPWRITE;
 	int rc, nr_subpages;
 	LIST_HEAD(ret_pages);
+	bool nosplit = (reason == MR_NUMA_MISPLACED);
 
 	trace_mm_migrate_pages_start(mode, reason);
 
@@ -1489,8 +1500,9 @@ retry:
 				/*
 				 * When memory is low, don't bother to try to migrate
 				 * other pages, just exit.
+				 * THP NUMA faulting doesn't split THP to retry.
 				 */
-				if (is_thp) {
+				if (is_thp && !nosplit) {
 					if (!try_split_thp(page, &page2, from)) {
 						nr_thp_split++;
 						goto retry;
@@ -2043,12 +2055,33 @@ static struct page *alloc_misplaced_dst_page(struct page *page,
 	return newpage;
 }
 
+static struct page *alloc_misplaced_dst_page_thp(struct page *page,
+						 unsigned long data)
+{
+	int nid = (int) data;
+	struct page *newpage;
+
+	newpage = alloc_pages_node(nid, (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE),
+				   HPAGE_PMD_ORDER);
+	if (!newpage)
+		goto out;
+
+	prep_transhuge_page(newpage);
+
+out:
+	return newpage;
+}
+
 static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 {
 	int page_lru;
 
 	VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page);
 
+	/* Do not migrate THP mapped by multiple processes */
+	if (PageTransHuge(page) && total_mapcount(page) > 1)
+		return 0;
+
 	/* Avoid migrating to a node that is nearly full */
 	if (!migrate_balanced_pgdat(pgdat, compound_nr(page)))
 		return 0;
@@ -2056,18 +2089,6 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 	if (isolate_lru_page(page))
 		return 0;
 
-	/*
-	 * migrate_misplaced_transhuge_page() skips page migration's usual
-	 * check on page_count(), so we must do it here, now that the page
-	 * has been isolated: a GUP pin, or any other pin, prevents migration.
-	 * The expected page count is 3: 1 for page's mapcount and 1 for the
-	 * caller's pin and 1 for the reference taken by isolate_lru_page().
-	 */
-	if (PageTransHuge(page) && page_count(page) != 3) {
-		putback_lru_page(page);
-		return 0;
-	}
-
 	page_lru = page_is_file_lru(page);
 	mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru,
 				thp_nr_pages(page));
@@ -2081,12 +2102,6 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 	return 1;
 }
 
-bool pmd_trans_migrating(pmd_t pmd)
-{
-	struct page *page = pmd_page(pmd);
-	return PageLocked(page);
-}
-
 /*
  * Attempt to migrate a misplaced page to the specified destination
  * node. Caller is expected to have an elevated reference count on
@@ -2099,6 +2114,21 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
 	int isolated;
 	int nr_remaining;
 	LIST_HEAD(migratepages);
+	new_page_t *new;
+	bool compound;
+	unsigned int nr_pages = thp_nr_pages(page);
+
+	/*
+	 * PTE mapped THP or HugeTLB page can't reach here so the page could
+	 * be either base page or THP.  And it must be head page if it is
+	 * THP.
+	 */
+	compound = PageTransHuge(page);
+
+	if (compound)
+		new = alloc_misplaced_dst_page_thp;
+	else
+		new = alloc_misplaced_dst_page;
 
 	/*
 	 * Don't migrate file pages that are mapped in multiple processes
@@ -2120,19 +2150,18 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
 		goto out;
 
 	list_add(&page->lru, &migratepages);
-	nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page,
-				     NULL, node, MIGRATE_ASYNC,
-				     MR_NUMA_MISPLACED);
+	nr_remaining = migrate_pages(&migratepages, *new, NULL, node,
+				     MIGRATE_ASYNC, MR_NUMA_MISPLACED);
 	if (nr_remaining) {
 		if (!list_empty(&migratepages)) {
 			list_del(&page->lru);
-			dec_node_page_state(page, NR_ISOLATED_ANON +
-					page_is_file_lru(page));
+			mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+					page_is_file_lru(page), -nr_pages);
 			putback_lru_page(page);
 		}
 		isolated = 0;
 	} else
-		count_vm_numa_event(NUMA_PAGE_MIGRATE);
+		count_vm_numa_events(NUMA_PAGE_MIGRATE, nr_pages);
 	BUG_ON(!list_empty(&migratepages));
 	return isolated;
 
@@ -2141,141 +2170,6 @@ out:
 	return 0;
 }
 #endif /* CONFIG_NUMA_BALANCING */
-
-#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
-/*
- * Migrates a THP to a given target node. page must be locked and is unlocked
- * before returning.
- */
-int migrate_misplaced_transhuge_page(struct mm_struct *mm,
-				struct vm_area_struct *vma,
-				pmd_t *pmd, pmd_t entry,
-				unsigned long address,
-				struct page *page, int node)
-{
-	spinlock_t *ptl;
-	pg_data_t *pgdat = NODE_DATA(node);
-	int isolated = 0;
-	struct page *new_page = NULL;
-	int page_lru = page_is_file_lru(page);
-	unsigned long start = address & HPAGE_PMD_MASK;
-
-	new_page = alloc_pages_node(node,
-		(GFP_TRANSHUGE_LIGHT | __GFP_THISNODE),
-		HPAGE_PMD_ORDER);
-	if (!new_page)
-		goto out_fail;
-	prep_transhuge_page(new_page);
-
-	isolated = numamigrate_isolate_page(pgdat, page);
-	if (!isolated) {
-		put_page(new_page);
-		goto out_fail;
-	}
-
-	/* Prepare a page as a migration target */
-	__SetPageLocked(new_page);
-	if (PageSwapBacked(page))
-		__SetPageSwapBacked(new_page);
-
-	/* anon mapping, we can simply copy page->mapping to the new page: */
-	new_page->mapping = page->mapping;
-	new_page->index = page->index;
-	/* flush the cache before copying using the kernel virtual address */
-	flush_cache_range(vma, start, start + HPAGE_PMD_SIZE);
-	migrate_page_copy(new_page, page);
-	WARN_ON(PageLRU(new_page));
-
-	/* Recheck the target PMD */
-	ptl = pmd_lock(mm, pmd);
-	if (unlikely(!pmd_same(*pmd, entry) || !page_ref_freeze(page, 2))) {
-		spin_unlock(ptl);
-
-		/* Reverse changes made by migrate_page_copy() */
-		if (TestClearPageActive(new_page))
-			SetPageActive(page);
-		if (TestClearPageUnevictable(new_page))
-			SetPageUnevictable(page);
-
-		unlock_page(new_page);
-		put_page(new_page);		/* Free it */
-
-		/* Retake the callers reference and putback on LRU */
-		get_page(page);
-		putback_lru_page(page);
-		mod_node_page_state(page_pgdat(page),
-			 NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR);
-
-		goto out_unlock;
-	}
-
-	entry = mk_huge_pmd(new_page, vma->vm_page_prot);
-	entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
-
-	/*
-	 * Overwrite the old entry under pagetable lock and establish
-	 * the new PTE. Any parallel GUP will either observe the old
-	 * page blocking on the page lock, block on the page table
-	 * lock or observe the new page. The SetPageUptodate on the
-	 * new page and page_add_new_anon_rmap guarantee the copy is
-	 * visible before the pagetable update.
-	 */
-	page_add_anon_rmap(new_page, vma, start, true);
-	/*
-	 * At this point the pmd is numa/protnone (i.e. non present) and the TLB
-	 * has already been flushed globally.  So no TLB can be currently
-	 * caching this non present pmd mapping.  There's no need to clear the
-	 * pmd before doing set_pmd_at(), nor to flush the TLB after
-	 * set_pmd_at().  Clearing the pmd here would introduce a race
-	 * condition against MADV_DONTNEED, because MADV_DONTNEED only holds the
-	 * mmap_lock for reading.  If the pmd is set to NULL at any given time,
-	 * MADV_DONTNEED won't wait on the pmd lock and it'll skip clearing this
-	 * pmd.
-	 */
-	set_pmd_at(mm, start, pmd, entry);
-	update_mmu_cache_pmd(vma, address, &entry);
-
-	page_ref_unfreeze(page, 2);
-	mlock_migrate_page(new_page, page);
-	page_remove_rmap(page, true);
-	set_page_owner_migrate_reason(new_page, MR_NUMA_MISPLACED);
-
-	spin_unlock(ptl);
-
-	/* Take an "isolate" reference and put new page on the LRU. */
-	get_page(new_page);
-	putback_lru_page(new_page);
-
-	unlock_page(new_page);
-	unlock_page(page);
-	put_page(page);			/* Drop the rmap reference */
-	put_page(page);			/* Drop the LRU isolation reference */
-
-	count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR);
-	count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR);
-
-	mod_node_page_state(page_pgdat(page),
-			NR_ISOLATED_ANON + page_lru,
-			-HPAGE_PMD_NR);
-	return isolated;
-
-out_fail:
-	count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
-	ptl = pmd_lock(mm, pmd);
-	if (pmd_same(*pmd, entry)) {
-		entry = pmd_modify(entry, vma->vm_page_prot);
-		set_pmd_at(mm, start, pmd, entry);
-		update_mmu_cache_pmd(vma, address, &entry);
-	}
-	spin_unlock(ptl);
-
-out_unlock:
-	unlock_page(page);
-	put_page(page);
-	return 0;
-}
-#endif /* CONFIG_NUMA_BALANCING */
-
 #endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_DEVICE_PRIVATE
@@ -2400,7 +2294,7 @@ again:
 			if (!is_device_private_entry(entry))
 				goto next;
 
-			page = device_private_entry_to_page(entry);
+			page = pfn_swap_entry_to_page(entry);
 			if (!(migrate->flags &
 				MIGRATE_VMA_SELECT_DEVICE_PRIVATE) ||
 			    page->pgmap->owner != migrate->pgmap_owner)
@@ -2408,7 +2302,7 @@ again:
 
 			mpfn = migrate_pfn(page_to_pfn(page)) |
 					MIGRATE_PFN_MIGRATE;
-			if (is_write_device_private_entry(entry))
+			if (is_writable_device_private_entry(entry))
 				mpfn |= MIGRATE_PFN_WRITE;
 		} else {
 			if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
@@ -2454,8 +2348,12 @@ again:
 			ptep_get_and_clear(mm, addr, ptep);
 
 			/* Setup special migration page table entry */
-			entry = make_migration_entry(page, mpfn &
-						     MIGRATE_PFN_WRITE);
+			if (mpfn & MIGRATE_PFN_WRITE)
+				entry = make_writable_migration_entry(
+							page_to_pfn(page));
+			else
+				entry = make_readable_migration_entry(
+							page_to_pfn(page));
 			swp_pte = swp_entry_to_pte(entry);
 			if (pte_present(pte)) {
 				if (pte_soft_dirty(pte))
@@ -2518,8 +2416,8 @@ static void migrate_vma_collect(struct migrate_vma *migrate)
 	 * that the registered device driver can skip invalidating device
 	 * private page mappings that won't be migrated.
 	 */
-	mmu_notifier_range_init_migrate(&range, 0, migrate->vma,
-		migrate->vma->vm_mm, migrate->start, migrate->end,
+	mmu_notifier_range_init_owner(&range, MMU_NOTIFY_MIGRATE, 0,
+		migrate->vma, migrate->vma->vm_mm, migrate->start, migrate->end,
 		migrate->pgmap_owner);
 	mmu_notifier_invalidate_range_start(&range);
 
@@ -2704,7 +2602,6 @@ static void migrate_vma_prepare(struct migrate_vma *migrate)
  */
 static void migrate_vma_unmap(struct migrate_vma *migrate)
 {
-	int flags = TTU_MIGRATION | TTU_IGNORE_MLOCK;
 	const unsigned long npages = migrate->npages;
 	const unsigned long start = migrate->start;
 	unsigned long addr, i, restore = 0;
@@ -2716,7 +2613,7 @@ static void migrate_vma_unmap(struct migrate_vma *migrate)
 			continue;
 
 		if (page_mapped(page)) {
-			try_to_unmap(page, flags);
+			try_to_migrate(page, 0);
 			if (page_mapped(page))
 				goto restore;
 		}
@@ -2928,7 +2825,12 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 		if (is_device_private_page(page)) {
 			swp_entry_t swp_entry;
 
-			swp_entry = make_device_private_entry(page, vma->vm_flags & VM_WRITE);
+			if (vma->vm_flags & VM_WRITE)
+				swp_entry = make_writable_device_private_entry(
+							page_to_pfn(page));
+			else
+				swp_entry = make_readable_device_private_entry(
+							page_to_pfn(page));
 			entry = swp_entry_to_pte(swp_entry);
 		} else {
 			/*
@@ -3025,9 +2927,9 @@ void migrate_vma_pages(struct migrate_vma *migrate)
 			if (!notified) {
 				notified = true;
 
-				mmu_notifier_range_init_migrate(&range, 0,
-					migrate->vma, migrate->vma->vm_mm,
-					addr, migrate->end,
+				mmu_notifier_range_init_owner(&range,
+					MMU_NOTIFY_MIGRATE, 0, migrate->vma,
+					migrate->vma->vm_mm, addr, migrate->end,
 					migrate->pgmap_owner);
 				mmu_notifier_invalidate_range_start(&range);
 			}
diff --git a/mm/mlock.c b/mm/mlock.c
index e338ebc4ad29..0d639bf48794 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -108,7 +108,7 @@ void mlock_vma_page(struct page *page)
 /*
  * Finish munlock after successful page isolation
  *
- * Page must be locked. This is a wrapper for try_to_munlock()
+ * Page must be locked. This is a wrapper for page_mlock()
  * and putback_lru_page() with munlock accounting.
  */
 static void __munlock_isolated_page(struct page *page)
@@ -118,7 +118,7 @@ static void __munlock_isolated_page(struct page *page)
 	 * and we don't need to check all the other vmas.
 	 */
 	if (page_mapcount(page) > 1)
-		try_to_munlock(page);
+		page_mlock(page);
 
 	/* Did try_to_unlock() succeed or punt? */
 	if (!PageMlocked(page))
@@ -158,7 +158,7 @@ static void __munlock_isolation_failed(struct page *page)
  * munlock()ed or munmap()ed, we want to check whether other vmas hold the
  * page locked so that we can leave it on the unevictable lru list and not
  * bother vmscan with it.  However, to walk the page's rmap list in
- * try_to_munlock() we must isolate the page from the LRU.  If some other
+ * page_mlock() we must isolate the page from the LRU.  If some other
  * task has removed the page from the LRU, we won't be able to do that.
  * So we clear the PageMlocked as we might not get another chance.  If we
  * can't isolate the page, we leave it for putback_lru_page() and vmscan
@@ -168,7 +168,7 @@ unsigned int munlock_vma_page(struct page *page)
 {
 	int nr_pages;
 
-	/* For try_to_munlock() and to serialize with page migration */
+	/* For page_mlock() and to serialize with page migration */
 	BUG_ON(!PageLocked(page));
 	VM_BUG_ON_PAGE(PageTail(page), page);
 
@@ -205,7 +205,7 @@ static int __mlock_posix_error_return(long retval)
  *
  * The fast path is available only for evictable pages with single mapping.
  * Then we can bypass the per-cpu pvec and get better performance.
- * when mapcount > 1 we need try_to_munlock() which can fail.
+ * when mapcount > 1 we need page_mlock() which can fail.
  * when !page_evictable(), we need the full redo logic of putback_lru_page to
  * avoid leaving evictable page in unevictable list.
  *
@@ -414,7 +414,7 @@ static unsigned long __munlock_pagevec_fill(struct pagevec *pvec,
  *
  * We don't save and restore VM_LOCKED here because pages are
  * still on lru.  In unmap path, pages might be scanned by reclaim
- * and re-mlocked by try_to_{munlock|unmap} before we unmap and
+ * and re-mlocked by page_mlock/try_to_unmap before we unmap and
  * free them.  This will result in freeing mlocked pages.
  */
 void munlock_vma_pages_range(struct vm_area_struct *vma,
diff --git a/mm/mmap_lock.c b/mm/mmap_lock.c
index 2ae3f33b85b1..f5852a058ce0 100644
--- a/mm/mmap_lock.c
+++ b/mm/mmap_lock.c
@@ -153,6 +153,37 @@ static inline void put_memcg_path_buf(void)
 	rcu_read_unlock();
 }
 
+#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \
+	do {                                                                   \
+		const char *memcg_path;                                        \
+		preempt_disable();                                             \
+		memcg_path = get_mm_memcg_path(mm);                            \
+		trace_mmap_lock_##type(mm,                                     \
+				       memcg_path != NULL ? memcg_path : "",   \
+				       ##__VA_ARGS__);                         \
+		if (likely(memcg_path != NULL))                                \
+			put_memcg_path_buf();                                  \
+		preempt_enable();                                              \
+	} while (0)
+
+#else /* !CONFIG_MEMCG */
+
+int trace_mmap_lock_reg(void)
+{
+	return 0;
+}
+
+void trace_mmap_lock_unreg(void)
+{
+}
+
+#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \
+	trace_mmap_lock_##type(mm, "", ##__VA_ARGS__)
+
+#endif /* CONFIG_MEMCG */
+
+#ifdef CONFIG_TRACING
+#ifdef CONFIG_MEMCG
 /*
  * Write the given mm_struct's memcg path to a percpu buffer, and return a
  * pointer to it. If the path cannot be determined, or no buffer was available
@@ -187,33 +218,6 @@ out:
 	return buf;
 }
 
-#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \
-	do {                                                                   \
-		const char *memcg_path;                                        \
-		local_lock(&memcg_paths.lock);				       \
-		memcg_path = get_mm_memcg_path(mm);                            \
-		trace_mmap_lock_##type(mm,                                     \
-				       memcg_path != NULL ? memcg_path : "",   \
-				       ##__VA_ARGS__);                         \
-		if (likely(memcg_path != NULL))                                \
-			put_memcg_path_buf();                                  \
-		local_unlock(&memcg_paths.lock);			       \
-	} while (0)
-
-#else /* !CONFIG_MEMCG */
-
-int trace_mmap_lock_reg(void)
-{
-	return 0;
-}
-
-void trace_mmap_lock_unreg(void)
-{
-}
-
-#define TRACE_MMAP_LOCK_EVENT(type, mm, ...)                                   \
-	trace_mmap_lock_##type(mm, "", ##__VA_ARGS__)
-
 #endif /* CONFIG_MEMCG */
 
 /*
@@ -239,3 +243,4 @@ void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write)
 	TRACE_MMAP_LOCK_EVENT(released, mm, write);
 }
 EXPORT_SYMBOL(__mmap_lock_do_trace_released);
+#endif /* CONFIG_TRACING */
diff --git a/mm/mprotect.c b/mm/mprotect.c
index e7a443157988..883e2cc85cad 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -143,26 +143,36 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 			swp_entry_t entry = pte_to_swp_entry(oldpte);
 			pte_t newpte;
 
-			if (is_write_migration_entry(entry)) {
+			if (is_writable_migration_entry(entry)) {
 				/*
 				 * A protection check is difficult so
 				 * just be safe and disable write
 				 */
-				make_migration_entry_read(&entry);
+				entry = make_readable_migration_entry(
+							swp_offset(entry));
 				newpte = swp_entry_to_pte(entry);
 				if (pte_swp_soft_dirty(oldpte))
 					newpte = pte_swp_mksoft_dirty(newpte);
 				if (pte_swp_uffd_wp(oldpte))
 					newpte = pte_swp_mkuffd_wp(newpte);
-			} else if (is_write_device_private_entry(entry)) {
+			} else if (is_writable_device_private_entry(entry)) {
 				/*
 				 * We do not preserve soft-dirtiness. See
 				 * copy_one_pte() for explanation.
 				 */
-				make_device_private_entry_read(&entry);
+				entry = make_readable_device_private_entry(
+							swp_offset(entry));
 				newpte = swp_entry_to_pte(entry);
 				if (pte_swp_uffd_wp(oldpte))
 					newpte = pte_swp_mkuffd_wp(newpte);
+			} else if (is_writable_device_exclusive_entry(entry)) {
+				entry = make_readable_device_exclusive_entry(
+							swp_offset(entry));
+				newpte = swp_entry_to_pte(entry);
+				if (pte_swp_soft_dirty(oldpte))
+					newpte = pte_swp_mksoft_dirty(newpte);
+				if (pte_swp_uffd_wp(oldpte))
+					newpte = pte_swp_mkuffd_wp(newpte);
 			} else {
 				newpte = oldpte;
 			}
diff --git a/mm/nommu.c b/mm/nommu.c
index affda71641ca..3a93d4054810 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -223,7 +223,7 @@ long vread(char *buf, char *addr, unsigned long count)
  */
 void *vmalloc(unsigned long size)
 {
-       return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM);
+	return __vmalloc(size, GFP_KERNEL);
 }
 EXPORT_SYMBOL(vmalloc);
 
@@ -241,7 +241,7 @@ EXPORT_SYMBOL(vmalloc);
  */
 void *vzalloc(unsigned long size)
 {
-	return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+	return __vmalloc(size, GFP_KERNEL | __GFP_ZERO);
 }
 EXPORT_SYMBOL(vzalloc);
 
@@ -1501,7 +1501,6 @@ erase_whole_vma:
 	delete_vma(mm, vma);
 	return 0;
 }
-EXPORT_SYMBOL(do_munmap);
 
 int vm_munmap(unsigned long addr, size_t len)
 {
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index eefd3f5fde46..fcc29e9a3064 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -104,7 +104,7 @@ static bool oom_cpuset_eligible(struct task_struct *start,
 			 * mempolicy intersects current, otherwise it may be
 			 * needlessly killed.
 			 */
-			ret = mempolicy_nodemask_intersects(tsk, mask);
+			ret = mempolicy_in_oom_domain(tsk, mask);
 		} else {
 			/*
 			 * This is not a mempolicy constrained oom, so only
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0817d88383d5..d6e94cc8066c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -749,7 +749,6 @@ void prep_compound_page(struct page *page, unsigned int order)
 	__SetPageHead(page);
 	for (i = 1; i < nr_pages; i++) {
 		struct page *p = page + i;
-		set_page_count(p, 0);
 		p->mapping = TAIL_MAPPING;
 		set_compound_head(p, page);
 	}
@@ -3193,7 +3192,7 @@ static void __drain_all_pages(struct zone *zone, bool force_all_cpus)
 	int cpu;
 
 	/*
-	 * Allocate in the BSS so we wont require allocation in
+	 * Allocate in the BSS so we won't require allocation in
 	 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
 	 */
 	static cpumask_t cpus_with_pcps;
@@ -3832,7 +3831,7 @@ static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
 
 #endif /* CONFIG_FAIL_PAGE_ALLOC */
 
-noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+static noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
 {
 	return __should_fail_alloc_page(gfp_mask, order);
 }
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index a4435311754b..f7b331081791 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -41,7 +41,8 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw)
 
 				/* Handle un-addressable ZONE_DEVICE memory */
 				entry = pte_to_swp_entry(*pvmw->pte);
-				if (!is_device_private_entry(entry))
+				if (!is_device_private_entry(entry) &&
+				    !is_device_exclusive_entry(entry))
 					return false;
 			} else if (!pte_present(*pvmw->pte))
 				return false;
@@ -93,19 +94,21 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw)
 			return false;
 		entry = pte_to_swp_entry(*pvmw->pte);
 
-		if (!is_migration_entry(entry))
+		if (!is_migration_entry(entry) &&
+		    !is_device_exclusive_entry(entry))
 			return false;
 
-		pfn = migration_entry_to_pfn(entry);
+		pfn = swp_offset(entry);
 	} else if (is_swap_pte(*pvmw->pte)) {
 		swp_entry_t entry;
 
 		/* Handle un-addressable ZONE_DEVICE memory */
 		entry = pte_to_swp_entry(*pvmw->pte);
-		if (!is_device_private_entry(entry))
+		if (!is_device_private_entry(entry) &&
+		    !is_device_exclusive_entry(entry))
 			return false;
 
-		pfn = device_private_entry_to_pfn(entry);
+		pfn = swp_offset(entry);
 	} else {
 		if (!pte_present(*pvmw->pte))
 			return false;
@@ -233,7 +236,7 @@ restart:
 					return not_found(pvmw);
 				entry = pmd_to_swp_entry(pmde);
 				if (!is_migration_entry(entry) ||
-				    migration_entry_to_page(entry) != page)
+				    pfn_swap_entry_to_page(entry) != page)
 					return not_found(pvmw);
 				return true;
 			}
diff --git a/mm/rmap.c b/mm/rmap.c
index e05c300048e6..37c24672125c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1405,24 +1405,14 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	/*
 	 * When racing against e.g. zap_pte_range() on another cpu,
 	 * in between its ptep_get_and_clear_full() and page_remove_rmap(),
-	 * try_to_unmap() may return false when it is about to become true,
+	 * try_to_unmap() may return before page_mapped() has become false,
 	 * if page table locking is skipped: use TTU_SYNC to wait for that.
 	 */
 	if (flags & TTU_SYNC)
 		pvmw.flags = PVMW_SYNC;
 
-	/* munlock has nothing to gain from examining un-locked vmas */
-	if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED))
-		return true;
-
-	if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION) &&
-	    is_zone_device_page(page) && !is_device_private_page(page))
-		return true;
-
-	if (flags & TTU_SPLIT_HUGE_PMD) {
-		split_huge_pmd_address(vma, address,
-				flags & TTU_SPLIT_FREEZE, page);
-	}
+	if (flags & TTU_SPLIT_HUGE_PMD)
+		split_huge_pmd_address(vma, address, false, page);
 
 	/*
 	 * For THP, we have to assume the worse case ie pmd for invalidation.
@@ -1447,16 +1437,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	mmu_notifier_invalidate_range_start(&range);
 
 	while (page_vma_mapped_walk(&pvmw)) {
-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
-		/* PMD-mapped THP migration entry */
-		if (!pvmw.pte && (flags & TTU_MIGRATION)) {
-			VM_BUG_ON_PAGE(PageHuge(page) || !PageTransCompound(page), page);
-
-			set_pmd_migration_entry(&pvmw, page);
-			continue;
-		}
-#endif
-
 		/*
 		 * If the page is mlock()d, we cannot swap it out.
 		 * If it's recently referenced (perhaps page_referenced
@@ -1476,8 +1456,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 				page_vma_mapped_walk_done(&pvmw);
 				break;
 			}
-			if (flags & TTU_MUNLOCK)
-				continue;
 		}
 
 		/* Unexpected PMD-mapped THP? */
@@ -1520,46 +1498,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 			}
 		}
 
-		if (IS_ENABLED(CONFIG_MIGRATION) &&
-		    (flags & TTU_MIGRATION) &&
-		    is_zone_device_page(page)) {
-			swp_entry_t entry;
-			pte_t swp_pte;
-
-			pteval = ptep_get_and_clear(mm, pvmw.address, pvmw.pte);
-
-			/*
-			 * Store the pfn of the page in a special migration
-			 * pte. do_swap_page() will wait until the migration
-			 * pte is removed and then restart fault handling.
-			 */
-			entry = make_migration_entry(page, 0);
-			swp_pte = swp_entry_to_pte(entry);
-
-			/*
-			 * pteval maps a zone device page and is therefore
-			 * a swap pte.
-			 */
-			if (pte_swp_soft_dirty(pteval))
-				swp_pte = pte_swp_mksoft_dirty(swp_pte);
-			if (pte_swp_uffd_wp(pteval))
-				swp_pte = pte_swp_mkuffd_wp(swp_pte);
-			set_pte_at(mm, pvmw.address, pvmw.pte, swp_pte);
-			/*
-			 * No need to invalidate here it will synchronize on
-			 * against the special swap migration pte.
-			 *
-			 * The assignment to subpage above was computed from a
-			 * swap PTE which results in an invalid pointer.
-			 * Since only PAGE_SIZE pages can currently be
-			 * migrated, just set it to page. This will need to be
-			 * changed when hugepage migrations to device private
-			 * memory are supported.
-			 */
-			subpage = page;
-			goto discard;
-		}
-
 		/* Nuke the page table entry. */
 		flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
 		if (should_defer_flush(mm, flags)) {
@@ -1612,35 +1550,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 			/* We have to invalidate as we cleared the pte */
 			mmu_notifier_invalidate_range(mm, address,
 						      address + PAGE_SIZE);
-		} else if (IS_ENABLED(CONFIG_MIGRATION) &&
-				(flags & (TTU_MIGRATION|TTU_SPLIT_FREEZE))) {
-			swp_entry_t entry;
-			pte_t swp_pte;
-
-			if (arch_unmap_one(mm, vma, address, pteval) < 0) {
-				set_pte_at(mm, address, pvmw.pte, pteval);
-				ret = false;
-				page_vma_mapped_walk_done(&pvmw);
-				break;
-			}
-
-			/*
-			 * Store the pfn of the page in a special migration
-			 * pte. do_swap_page() will wait until the migration
-			 * pte is removed and then restart fault handling.
-			 */
-			entry = make_migration_entry(subpage,
-					pte_write(pteval));
-			swp_pte = swp_entry_to_pte(entry);
-			if (pte_soft_dirty(pteval))
-				swp_pte = pte_swp_mksoft_dirty(swp_pte);
-			if (pte_uffd_wp(pteval))
-				swp_pte = pte_swp_mkuffd_wp(swp_pte);
-			set_pte_at(mm, address, pvmw.pte, swp_pte);
-			/*
-			 * No need to invalidate here it will synchronize on
-			 * against the special swap migration pte.
-			 */
 		} else if (PageAnon(page)) {
 			swp_entry_t entry = { .val = page_private(subpage) };
 			pte_t swp_pte;
@@ -1756,9 +1665,10 @@ static int page_not_mapped(struct page *page)
  * Tries to remove all the page table entries which are mapping this
  * page, used in the pageout path.  Caller must hold the page lock.
  *
- * If unmap is successful, return true. Otherwise, false.
+ * It is the caller's responsibility to check if the page is still
+ * mapped when needed (use TTU_SYNC to prevent accounting races).
  */
-bool try_to_unmap(struct page *page, enum ttu_flags flags)
+void try_to_unmap(struct page *page, enum ttu_flags flags)
 {
 	struct rmap_walk_control rwc = {
 		.rmap_one = try_to_unmap_one,
@@ -1767,6 +1677,277 @@ bool try_to_unmap(struct page *page, enum ttu_flags flags)
 		.anon_lock = page_lock_anon_vma_read,
 	};
 
+	if (flags & TTU_RMAP_LOCKED)
+		rmap_walk_locked(page, &rwc);
+	else
+		rmap_walk(page, &rwc);
+}
+
+/*
+ * @arg: enum ttu_flags will be passed to this argument.
+ *
+ * If TTU_SPLIT_HUGE_PMD is specified any PMD mappings will be split into PTEs
+ * containing migration entries. This and TTU_RMAP_LOCKED are the only supported
+ * flags.
+ */
+static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma,
+		     unsigned long address, void *arg)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	struct page_vma_mapped_walk pvmw = {
+		.page = page,
+		.vma = vma,
+		.address = address,
+	};
+	pte_t pteval;
+	struct page *subpage;
+	bool ret = true;
+	struct mmu_notifier_range range;
+	enum ttu_flags flags = (enum ttu_flags)(long)arg;
+
+	if (is_zone_device_page(page) && !is_device_private_page(page))
+		return true;
+
+	/*
+	 * When racing against e.g. zap_pte_range() on another cpu,
+	 * in between its ptep_get_and_clear_full() and page_remove_rmap(),
+	 * try_to_migrate() may return before page_mapped() has become false,
+	 * if page table locking is skipped: use TTU_SYNC to wait for that.
+	 */
+	if (flags & TTU_SYNC)
+		pvmw.flags = PVMW_SYNC;
+
+	/*
+	 * unmap_page() in mm/huge_memory.c is the only user of migration with
+	 * TTU_SPLIT_HUGE_PMD and it wants to freeze.
+	 */
+	if (flags & TTU_SPLIT_HUGE_PMD)
+		split_huge_pmd_address(vma, address, true, page);
+
+	/*
+	 * For THP, we have to assume the worse case ie pmd for invalidation.
+	 * For hugetlb, it could be much worse if we need to do pud
+	 * invalidation in the case of pmd sharing.
+	 *
+	 * Note that the page can not be free in this function as call of
+	 * try_to_unmap() must hold a reference on the page.
+	 */
+	range.end = PageKsm(page) ?
+			address + PAGE_SIZE : vma_address_end(page, vma);
+	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
+				address, range.end);
+	if (PageHuge(page)) {
+		/*
+		 * If sharing is possible, start and end will be adjusted
+		 * accordingly.
+		 */
+		adjust_range_if_pmd_sharing_possible(vma, &range.start,
+						     &range.end);
+	}
+	mmu_notifier_invalidate_range_start(&range);
+
+	while (page_vma_mapped_walk(&pvmw)) {
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+		/* PMD-mapped THP migration entry */
+		if (!pvmw.pte) {
+			VM_BUG_ON_PAGE(PageHuge(page) ||
+				       !PageTransCompound(page), page);
+
+			set_pmd_migration_entry(&pvmw, page);
+			continue;
+		}
+#endif
+
+		/* Unexpected PMD-mapped THP? */
+		VM_BUG_ON_PAGE(!pvmw.pte, page);
+
+		subpage = page - page_to_pfn(page) + pte_pfn(*pvmw.pte);
+		address = pvmw.address;
+
+		if (PageHuge(page) && !PageAnon(page)) {
+			/*
+			 * To call huge_pmd_unshare, i_mmap_rwsem must be
+			 * held in write mode.  Caller needs to explicitly
+			 * do this outside rmap routines.
+			 */
+			VM_BUG_ON(!(flags & TTU_RMAP_LOCKED));
+			if (huge_pmd_unshare(mm, vma, &address, pvmw.pte)) {
+				/*
+				 * huge_pmd_unshare unmapped an entire PMD
+				 * page.  There is no way of knowing exactly
+				 * which PMDs may be cached for this mm, so
+				 * we must flush them all.  start/end were
+				 * already adjusted above to cover this range.
+				 */
+				flush_cache_range(vma, range.start, range.end);
+				flush_tlb_range(vma, range.start, range.end);
+				mmu_notifier_invalidate_range(mm, range.start,
+							      range.end);
+
+				/*
+				 * The ref count of the PMD page was dropped
+				 * which is part of the way map counting
+				 * is done for shared PMDs.  Return 'true'
+				 * here.  When there is no other sharing,
+				 * huge_pmd_unshare returns false and we will
+				 * unmap the actual page and drop map count
+				 * to zero.
+				 */
+				page_vma_mapped_walk_done(&pvmw);
+				break;
+			}
+		}
+
+		/* Nuke the page table entry. */
+		flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
+		pteval = ptep_clear_flush(vma, address, pvmw.pte);
+
+		/* Move the dirty bit to the page. Now the pte is gone. */
+		if (pte_dirty(pteval))
+			set_page_dirty(page);
+
+		/* Update high watermark before we lower rss */
+		update_hiwater_rss(mm);
+
+		if (is_zone_device_page(page)) {
+			swp_entry_t entry;
+			pte_t swp_pte;
+
+			/*
+			 * Store the pfn of the page in a special migration
+			 * pte. do_swap_page() will wait until the migration
+			 * pte is removed and then restart fault handling.
+			 */
+			entry = make_readable_migration_entry(
+							page_to_pfn(page));
+			swp_pte = swp_entry_to_pte(entry);
+
+			/*
+			 * pteval maps a zone device page and is therefore
+			 * a swap pte.
+			 */
+			if (pte_swp_soft_dirty(pteval))
+				swp_pte = pte_swp_mksoft_dirty(swp_pte);
+			if (pte_swp_uffd_wp(pteval))
+				swp_pte = pte_swp_mkuffd_wp(swp_pte);
+			set_pte_at(mm, pvmw.address, pvmw.pte, swp_pte);
+			/*
+			 * No need to invalidate here it will synchronize on
+			 * against the special swap migration pte.
+			 *
+			 * The assignment to subpage above was computed from a
+			 * swap PTE which results in an invalid pointer.
+			 * Since only PAGE_SIZE pages can currently be
+			 * migrated, just set it to page. This will need to be
+			 * changed when hugepage migrations to device private
+			 * memory are supported.
+			 */
+			subpage = page;
+		} else if (PageHWPoison(page)) {
+			pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
+			if (PageHuge(page)) {
+				hugetlb_count_sub(compound_nr(page), mm);
+				set_huge_swap_pte_at(mm, address,
+						     pvmw.pte, pteval,
+						     vma_mmu_pagesize(vma));
+			} else {
+				dec_mm_counter(mm, mm_counter(page));
+				set_pte_at(mm, address, pvmw.pte, pteval);
+			}
+
+		} else if (pte_unused(pteval) && !userfaultfd_armed(vma)) {
+			/*
+			 * The guest indicated that the page content is of no
+			 * interest anymore. Simply discard the pte, vmscan
+			 * will take care of the rest.
+			 * A future reference will then fault in a new zero
+			 * page. When userfaultfd is active, we must not drop
+			 * this page though, as its main user (postcopy
+			 * migration) will not expect userfaults on already
+			 * copied pages.
+			 */
+			dec_mm_counter(mm, mm_counter(page));
+			/* We have to invalidate as we cleared the pte */
+			mmu_notifier_invalidate_range(mm, address,
+						      address + PAGE_SIZE);
+		} else {
+			swp_entry_t entry;
+			pte_t swp_pte;
+
+			if (arch_unmap_one(mm, vma, address, pteval) < 0) {
+				set_pte_at(mm, address, pvmw.pte, pteval);
+				ret = false;
+				page_vma_mapped_walk_done(&pvmw);
+				break;
+			}
+
+			/*
+			 * Store the pfn of the page in a special migration
+			 * pte. do_swap_page() will wait until the migration
+			 * pte is removed and then restart fault handling.
+			 */
+			if (pte_write(pteval))
+				entry = make_writable_migration_entry(
+							page_to_pfn(subpage));
+			else
+				entry = make_readable_migration_entry(
+							page_to_pfn(subpage));
+
+			swp_pte = swp_entry_to_pte(entry);
+			if (pte_soft_dirty(pteval))
+				swp_pte = pte_swp_mksoft_dirty(swp_pte);
+			if (pte_uffd_wp(pteval))
+				swp_pte = pte_swp_mkuffd_wp(swp_pte);
+			set_pte_at(mm, address, pvmw.pte, swp_pte);
+			/*
+			 * No need to invalidate here it will synchronize on
+			 * against the special swap migration pte.
+			 */
+		}
+
+		/*
+		 * No need to call mmu_notifier_invalidate_range() it has be
+		 * done above for all cases requiring it to happen under page
+		 * table lock before mmu_notifier_invalidate_range_end()
+		 *
+		 * See Documentation/vm/mmu_notifier.rst
+		 */
+		page_remove_rmap(subpage, PageHuge(page));
+		put_page(page);
+	}
+
+	mmu_notifier_invalidate_range_end(&range);
+
+	return ret;
+}
+
+/**
+ * try_to_migrate - try to replace all page table mappings with swap entries
+ * @page: the page to replace page table entries for
+ * @flags: action and flags
+ *
+ * Tries to remove all the page table entries which are mapping this page and
+ * replace them with special swap entries. Caller must hold the page lock.
+ *
+ * If is successful, return true. Otherwise, false.
+ */
+void try_to_migrate(struct page *page, enum ttu_flags flags)
+{
+	struct rmap_walk_control rwc = {
+		.rmap_one = try_to_migrate_one,
+		.arg = (void *)flags,
+		.done = page_not_mapped,
+		.anon_lock = page_lock_anon_vma_read,
+	};
+
+	/*
+	 * Migration always ignores mlock and only supports TTU_RMAP_LOCKED and
+	 * TTU_SPLIT_HUGE_PMD and TTU_SYNC flags.
+	 */
+	if (WARN_ON_ONCE(flags & ~(TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD |
+					TTU_SYNC)))
+		return;
+
 	/*
 	 * During exec, a temporary VMA is setup and later moved.
 	 * The VMA is moved under the anon_vma lock but not the
@@ -1775,38 +1956,67 @@ bool try_to_unmap(struct page *page, enum ttu_flags flags)
 	 * locking requirements of exec(), migration skips
 	 * temporary VMAs until after exec() completes.
 	 */
-	if ((flags & (TTU_MIGRATION|TTU_SPLIT_FREEZE))
-	    && !PageKsm(page) && PageAnon(page))
+	if (!PageKsm(page) && PageAnon(page))
 		rwc.invalid_vma = invalid_migration_vma;
 
 	if (flags & TTU_RMAP_LOCKED)
 		rmap_walk_locked(page, &rwc);
 	else
 		rmap_walk(page, &rwc);
+}
 
-	/*
-	 * When racing against e.g. zap_pte_range() on another cpu,
-	 * in between its ptep_get_and_clear_full() and page_remove_rmap(),
-	 * try_to_unmap() may return false when it is about to become true,
-	 * if page table locking is skipped: use TTU_SYNC to wait for that.
-	 */
-	return !page_mapcount(page);
+/*
+ * Walks the vma's mapping a page and mlocks the page if any locked vma's are
+ * found. Once one is found the page is locked and the scan can be terminated.
+ */
+static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
+				 unsigned long address, void *unused)
+{
+	struct page_vma_mapped_walk pvmw = {
+		.page = page,
+		.vma = vma,
+		.address = address,
+	};
+
+	/* An un-locked vma doesn't have any pages to lock, continue the scan */
+	if (!(vma->vm_flags & VM_LOCKED))
+		return true;
+
+	while (page_vma_mapped_walk(&pvmw)) {
+		/*
+		 * Need to recheck under the ptl to serialise with
+		 * __munlock_pagevec_fill() after VM_LOCKED is cleared in
+		 * munlock_vma_pages_range().
+		 */
+		if (vma->vm_flags & VM_LOCKED) {
+			/* PTE-mapped THP are never mlocked */
+			if (!PageTransCompound(page))
+				mlock_vma_page(page);
+			page_vma_mapped_walk_done(&pvmw);
+		}
+
+		/*
+		 * no need to continue scanning other vma's if the page has
+		 * been locked.
+		 */
+		return false;
+	}
+
+	return true;
 }
 
 /**
- * try_to_munlock - try to munlock a page
- * @page: the page to be munlocked
+ * page_mlock - try to mlock a page
+ * @page: the page to be mlocked
  *
- * Called from munlock code.  Checks all of the VMAs mapping the page
- * to make sure nobody else has this page mlocked. The page will be
- * returned with PG_mlocked cleared if no other vmas have it mlocked.
+ * Called from munlock code. Checks all of the VMAs mapping the page and mlocks
+ * the page if any are found. The page will be returned with PG_mlocked cleared
+ * if it is not mapped by any locked vmas.
  */
-
-void try_to_munlock(struct page *page)
+void page_mlock(struct page *page)
 {
 	struct rmap_walk_control rwc = {
-		.rmap_one = try_to_unmap_one,
-		.arg = (void *)TTU_MUNLOCK,
+		.rmap_one = page_mlock_one,
 		.done = page_not_mapped,
 		.anon_lock = page_lock_anon_vma_read,
 
@@ -1818,6 +2028,192 @@ void try_to_munlock(struct page *page)
 	rmap_walk(page, &rwc);
 }
 
+#ifdef CONFIG_DEVICE_PRIVATE
+struct make_exclusive_args {
+	struct mm_struct *mm;
+	unsigned long address;
+	void *owner;
+	bool valid;
+};
+
+static bool page_make_device_exclusive_one(struct page *page,
+		struct vm_area_struct *vma, unsigned long address, void *priv)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	struct page_vma_mapped_walk pvmw = {
+		.page = page,
+		.vma = vma,
+		.address = address,
+	};
+	struct make_exclusive_args *args = priv;
+	pte_t pteval;
+	struct page *subpage;
+	bool ret = true;
+	struct mmu_notifier_range range;
+	swp_entry_t entry;
+	pte_t swp_pte;
+
+	mmu_notifier_range_init_owner(&range, MMU_NOTIFY_EXCLUSIVE, 0, vma,
+				      vma->vm_mm, address, min(vma->vm_end,
+				      address + page_size(page)), args->owner);
+	mmu_notifier_invalidate_range_start(&range);
+
+	while (page_vma_mapped_walk(&pvmw)) {
+		/* Unexpected PMD-mapped THP? */
+		VM_BUG_ON_PAGE(!pvmw.pte, page);
+
+		if (!pte_present(*pvmw.pte)) {
+			ret = false;
+			page_vma_mapped_walk_done(&pvmw);
+			break;
+		}
+
+		subpage = page - page_to_pfn(page) + pte_pfn(*pvmw.pte);
+		address = pvmw.address;
+
+		/* Nuke the page table entry. */
+		flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
+		pteval = ptep_clear_flush(vma, address, pvmw.pte);
+
+		/* Move the dirty bit to the page. Now the pte is gone. */
+		if (pte_dirty(pteval))
+			set_page_dirty(page);
+
+		/*
+		 * Check that our target page is still mapped at the expected
+		 * address.
+		 */
+		if (args->mm == mm && args->address == address &&
+		    pte_write(pteval))
+			args->valid = true;
+
+		/*
+		 * Store the pfn of the page in a special migration
+		 * pte. do_swap_page() will wait until the migration
+		 * pte is removed and then restart fault handling.
+		 */
+		if (pte_write(pteval))
+			entry = make_writable_device_exclusive_entry(
+							page_to_pfn(subpage));
+		else
+			entry = make_readable_device_exclusive_entry(
+							page_to_pfn(subpage));
+		swp_pte = swp_entry_to_pte(entry);
+		if (pte_soft_dirty(pteval))
+			swp_pte = pte_swp_mksoft_dirty(swp_pte);
+		if (pte_uffd_wp(pteval))
+			swp_pte = pte_swp_mkuffd_wp(swp_pte);
+
+		set_pte_at(mm, address, pvmw.pte, swp_pte);
+
+		/*
+		 * There is a reference on the page for the swap entry which has
+		 * been removed, so shouldn't take another.
+		 */
+		page_remove_rmap(subpage, false);
+	}
+
+	mmu_notifier_invalidate_range_end(&range);
+
+	return ret;
+}
+
+/**
+ * page_make_device_exclusive - mark the page exclusively owned by a device
+ * @page: the page to replace page table entries for
+ * @mm: the mm_struct where the page is expected to be mapped
+ * @address: address where the page is expected to be mapped
+ * @owner: passed to MMU_NOTIFY_EXCLUSIVE range notifier callbacks
+ *
+ * Tries to remove all the page table entries which are mapping this page and
+ * replace them with special device exclusive swap entries to grant a device
+ * exclusive access to the page. Caller must hold the page lock.
+ *
+ * Returns false if the page is still mapped, or if it could not be unmapped
+ * from the expected address. Otherwise returns true (success).
+ */
+static bool page_make_device_exclusive(struct page *page, struct mm_struct *mm,
+				unsigned long address, void *owner)
+{
+	struct make_exclusive_args args = {
+		.mm = mm,
+		.address = address,
+		.owner = owner,
+		.valid = false,
+	};
+	struct rmap_walk_control rwc = {
+		.rmap_one = page_make_device_exclusive_one,
+		.done = page_not_mapped,
+		.anon_lock = page_lock_anon_vma_read,
+		.arg = &args,
+	};
+
+	/*
+	 * Restrict to anonymous pages for now to avoid potential writeback
+	 * issues. Also tail pages shouldn't be passed to rmap_walk so skip
+	 * those.
+	 */
+	if (!PageAnon(page) || PageTail(page))
+		return false;
+
+	rmap_walk(page, &rwc);
+
+	return args.valid && !page_mapcount(page);
+}
+
+/**
+ * make_device_exclusive_range() - Mark a range for exclusive use by a device
+ * @mm: mm_struct of assoicated target process
+ * @start: start of the region to mark for exclusive device access
+ * @end: end address of region
+ * @pages: returns the pages which were successfully marked for exclusive access
+ * @owner: passed to MMU_NOTIFY_EXCLUSIVE range notifier to allow filtering
+ *
+ * Returns: number of pages found in the range by GUP. A page is marked for
+ * exclusive access only if the page pointer is non-NULL.
+ *
+ * This function finds ptes mapping page(s) to the given address range, locks
+ * them and replaces mappings with special swap entries preventing userspace CPU
+ * access. On fault these entries are replaced with the original mapping after
+ * calling MMU notifiers.
+ *
+ * A driver using this to program access from a device must use a mmu notifier
+ * critical section to hold a device specific lock during programming. Once
+ * programming is complete it should drop the page lock and reference after
+ * which point CPU access to the page will revoke the exclusive access.
+ */
+int make_device_exclusive_range(struct mm_struct *mm, unsigned long start,
+				unsigned long end, struct page **pages,
+				void *owner)
+{
+	long npages = (end - start) >> PAGE_SHIFT;
+	long i;
+
+	npages = get_user_pages_remote(mm, start, npages,
+				       FOLL_GET | FOLL_WRITE | FOLL_SPLIT_PMD,
+				       pages, NULL, NULL);
+	if (npages < 0)
+		return npages;
+
+	for (i = 0; i < npages; i++, start += PAGE_SIZE) {
+		if (!trylock_page(pages[i])) {
+			put_page(pages[i]);
+			pages[i] = NULL;
+			continue;
+		}
+
+		if (!page_make_device_exclusive(pages[i], mm, start, owner)) {
+			unlock_page(pages[i]);
+			put_page(pages[i]);
+			pages[i] = NULL;
+		}
+	}
+
+	return npages;
+}
+EXPORT_SYMBOL_GPL(make_device_exclusive_range);
+#endif
+
 void __put_anon_vma(struct anon_vma *anon_vma)
 {
 	struct anon_vma *root = anon_vma->root;
@@ -1858,7 +2254,7 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page,
  * Find all the mappings of a page using the mapping pointer and the vma chains
  * contained in the anon_vma struct it points to.
  *
- * When called from try_to_munlock(), the mmap_lock of the mm containing the vma
+ * When called from page_mlock(), the mmap_lock of the mm containing the vma
  * where the page was found will be held for write.  So, we won't recheck
  * vm_flags for that VMA.  That should be OK, because that vma shouldn't be
  * LOCKED.
@@ -1911,7 +2307,7 @@ static void rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
  * Find all the mappings of a page using the mapping pointer and the vma chains
  * contained in the address_space struct it points to.
  *
- * When called from try_to_munlock(), the mmap_lock of the mm containing the vma
+ * When called from page_mlock(), the mmap_lock of the mm containing the vma
  * where the page was found will be held for write.  So, we won't recheck
  * vm_flags for that VMA.  That should be OK, because that vma shouldn't be
  * LOCKED.
diff --git a/mm/shmem.c b/mm/shmem.c
index 6268b9b4e41a..70d9ce294bb4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1797,7 +1797,7 @@ unlock:
  * vm. If we swap it in we mark it dirty since we also free the swap
  * entry since a page cannot live in both the swap and page cache.
  *
- * vmf and fault_type are only supplied by shmem_fault:
+ * vma, vmf, and fault_type are only supplied by shmem_fault:
  * otherwise they are NULL.
  */
 static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
@@ -1832,6 +1832,16 @@ repeat:
 
 	page = pagecache_get_page(mapping, index,
 					FGP_ENTRY | FGP_HEAD | FGP_LOCK, 0);
+
+	if (page && vma && userfaultfd_minor(vma)) {
+		if (!xa_is_value(page)) {
+			unlock_page(page);
+			put_page(page);
+		}
+		*fault_type = handle_userfault(vmf, VM_UFFD_MINOR);
+		return 0;
+	}
+
 	if (xa_is_value(page)) {
 		error = shmem_swapin_page(inode, index, &page,
 					  sgp, gfp, vma, fault_type);
@@ -2352,27 +2362,25 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
 	return inode;
 }
 
-static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
-				  pmd_t *dst_pmd,
-				  struct vm_area_struct *dst_vma,
-				  unsigned long dst_addr,
-				  unsigned long src_addr,
-				  bool zeropage,
-				  struct page **pagep)
+#ifdef CONFIG_USERFAULTFD
+int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
+			   pmd_t *dst_pmd,
+			   struct vm_area_struct *dst_vma,
+			   unsigned long dst_addr,
+			   unsigned long src_addr,
+			   bool zeropage,
+			   struct page **pagep)
 {
 	struct inode *inode = file_inode(dst_vma->vm_file);
 	struct shmem_inode_info *info = SHMEM_I(inode);
 	struct address_space *mapping = inode->i_mapping;
 	gfp_t gfp = mapping_gfp_mask(mapping);
 	pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
-	spinlock_t *ptl;
 	void *page_kaddr;
 	struct page *page;
-	pte_t _dst_pte, *dst_pte;
 	int ret;
-	pgoff_t offset, max_off;
+	pgoff_t max_off;
 
-	ret = -ENOMEM;
 	if (!shmem_inode_acct_block(inode, 1)) {
 		/*
 		 * We may have got a page, returned -ENOENT triggering a retry,
@@ -2383,15 +2391,16 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 			put_page(*pagep);
 			*pagep = NULL;
 		}
-		goto out;
+		return -ENOMEM;
 	}
 
 	if (!*pagep) {
+		ret = -ENOMEM;
 		page = shmem_alloc_page(gfp, info, pgoff);
 		if (!page)
 			goto out_unacct_blocks;
 
-		if (!zeropage) {	/* mcopy_atomic */
+		if (!zeropage) {	/* COPY */
 			page_kaddr = kmap_atomic(page);
 			ret = copy_from_user(page_kaddr,
 					     (const void __user *)src_addr,
@@ -2401,11 +2410,11 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 			/* fallback to copy_from_user outside mmap_lock */
 			if (unlikely(ret)) {
 				*pagep = page;
-				shmem_inode_unacct_blocks(inode, 1);
+				ret = -ENOENT;
 				/* don't free the page */
-				return -ENOENT;
+				goto out_unacct_blocks;
 			}
-		} else {		/* mfill_zeropage_atomic */
+		} else {		/* ZEROPAGE */
 			clear_highpage(page);
 		}
 	} else {
@@ -2413,15 +2422,15 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 		*pagep = NULL;
 	}
 
-	VM_BUG_ON(PageLocked(page) || PageSwapBacked(page));
+	VM_BUG_ON(PageLocked(page));
+	VM_BUG_ON(PageSwapBacked(page));
 	__SetPageLocked(page);
 	__SetPageSwapBacked(page);
 	__SetPageUptodate(page);
 
 	ret = -EFAULT;
-	offset = linear_page_index(dst_vma, dst_addr);
 	max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
-	if (unlikely(offset >= max_off))
+	if (unlikely(pgoff >= max_off))
 		goto out_release;
 
 	ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL,
@@ -2429,32 +2438,10 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 	if (ret)
 		goto out_release;
 
-	_dst_pte = mk_pte(page, dst_vma->vm_page_prot);
-	if (dst_vma->vm_flags & VM_WRITE)
-		_dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte));
-	else {
-		/*
-		 * We don't set the pte dirty if the vma has no
-		 * VM_WRITE permission, so mark the page dirty or it
-		 * could be freed from under us. We could do it
-		 * unconditionally before unlock_page(), but doing it
-		 * only if VM_WRITE is not set is faster.
-		 */
-		set_page_dirty(page);
-	}
-
-	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
-
-	ret = -EFAULT;
-	max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
-	if (unlikely(offset >= max_off))
-		goto out_release_unlock;
-
-	ret = -EEXIST;
-	if (!pte_none(*dst_pte))
-		goto out_release_unlock;
-
-	lru_cache_add(page);
+	ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
+				       page, true, false);
+	if (ret)
+		goto out_delete_from_cache;
 
 	spin_lock_irq(&info->lock);
 	info->alloced++;
@@ -2462,50 +2449,19 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 	shmem_recalc_inode(inode);
 	spin_unlock_irq(&info->lock);
 
-	inc_mm_counter(dst_mm, mm_counter_file(page));
-	page_add_file_rmap(page, false);
-	set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
-
-	/* No need to invalidate - it was non-present before */
-	update_mmu_cache(dst_vma, dst_addr, dst_pte);
-	pte_unmap_unlock(dst_pte, ptl);
+	SetPageDirty(page);
 	unlock_page(page);
-	ret = 0;
-out:
-	return ret;
-out_release_unlock:
-	pte_unmap_unlock(dst_pte, ptl);
-	ClearPageDirty(page);
+	return 0;
+out_delete_from_cache:
 	delete_from_page_cache(page);
 out_release:
 	unlock_page(page);
 	put_page(page);
 out_unacct_blocks:
 	shmem_inode_unacct_blocks(inode, 1);
-	goto out;
-}
-
-int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm,
-			   pmd_t *dst_pmd,
-			   struct vm_area_struct *dst_vma,
-			   unsigned long dst_addr,
-			   unsigned long src_addr,
-			   struct page **pagep)
-{
-	return shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma,
-				      dst_addr, src_addr, false, pagep);
-}
-
-int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm,
-			     pmd_t *dst_pmd,
-			     struct vm_area_struct *dst_vma,
-			     unsigned long dst_addr)
-{
-	struct page *page = NULL;
-
-	return shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma,
-				      dst_addr, 0, true, &page);
+	return ret;
 }
+#endif /* CONFIG_USERFAULTFD */
 
 #ifdef CONFIG_TMPFS
 static const struct inode_operations shmem_symlink_inode_operations;
@@ -4040,8 +3996,7 @@ bool shmem_huge_enabled(struct vm_area_struct *vma)
 	loff_t i_size;
 	pgoff_t off;
 
-	if ((vma->vm_flags & VM_NOHUGEPAGE) ||
-	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+	if (!transhuge_vma_enabled(vma, vma->vm_flags))
 		return false;
 	if (shmem_huge == SHMEM_HUGE_FORCE)
 		return true;
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 16183d85a7d5..bdce883f9286 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -27,8 +27,362 @@
 #include <linux/spinlock.h>
 #include <linux/vmalloc.h>
 #include <linux/sched.h>
+#include <linux/pgtable.h>
+#include <linux/bootmem_info.h>
+
 #include <asm/dma.h>
 #include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+
+/**
+ * struct vmemmap_remap_walk - walk vmemmap page table
+ *
+ * @remap_pte:		called for each lowest-level entry (PTE).
+ * @nr_walked:		the number of walked pte.
+ * @reuse_page:		the page which is reused for the tail vmemmap pages.
+ * @reuse_addr:		the virtual address of the @reuse_page page.
+ * @vmemmap_pages:	the list head of the vmemmap pages that can be freed
+ *			or is mapped from.
+ */
+struct vmemmap_remap_walk {
+	void (*remap_pte)(pte_t *pte, unsigned long addr,
+			  struct vmemmap_remap_walk *walk);
+	unsigned long nr_walked;
+	struct page *reuse_page;
+	unsigned long reuse_addr;
+	struct list_head *vmemmap_pages;
+};
+
+static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start,
+				  struct vmemmap_remap_walk *walk)
+{
+	pmd_t __pmd;
+	int i;
+	unsigned long addr = start;
+	struct page *page = pmd_page(*pmd);
+	pte_t *pgtable = pte_alloc_one_kernel(&init_mm);
+
+	if (!pgtable)
+		return -ENOMEM;
+
+	pmd_populate_kernel(&init_mm, &__pmd, pgtable);
+
+	for (i = 0; i < PMD_SIZE / PAGE_SIZE; i++, addr += PAGE_SIZE) {
+		pte_t entry, *pte;
+		pgprot_t pgprot = PAGE_KERNEL;
+
+		entry = mk_pte(page + i, pgprot);
+		pte = pte_offset_kernel(&__pmd, addr);
+		set_pte_at(&init_mm, addr, pte, entry);
+	}
+
+	/* Make pte visible before pmd. See comment in __pte_alloc(). */
+	smp_wmb();
+	pmd_populate_kernel(&init_mm, pmd, pgtable);
+
+	flush_tlb_kernel_range(start, start + PMD_SIZE);
+
+	return 0;
+}
+
+static void vmemmap_pte_range(pmd_t *pmd, unsigned long addr,
+			      unsigned long end,
+			      struct vmemmap_remap_walk *walk)
+{
+	pte_t *pte = pte_offset_kernel(pmd, addr);
+
+	/*
+	 * The reuse_page is found 'first' in table walk before we start
+	 * remapping (which is calling @walk->remap_pte).
+	 */
+	if (!walk->reuse_page) {
+		walk->reuse_page = pte_page(*pte);
+		/*
+		 * Because the reuse address is part of the range that we are
+		 * walking, skip the reuse address range.
+		 */
+		addr += PAGE_SIZE;
+		pte++;
+		walk->nr_walked++;
+	}
+
+	for (; addr != end; addr += PAGE_SIZE, pte++) {
+		walk->remap_pte(pte, addr, walk);
+		walk->nr_walked++;
+	}
+}
+
+static int vmemmap_pmd_range(pud_t *pud, unsigned long addr,
+			     unsigned long end,
+			     struct vmemmap_remap_walk *walk)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	pmd = pmd_offset(pud, addr);
+	do {
+		if (pmd_leaf(*pmd)) {
+			int ret;
+
+			ret = split_vmemmap_huge_pmd(pmd, addr & PMD_MASK, walk);
+			if (ret)
+				return ret;
+		}
+		next = pmd_addr_end(addr, end);
+		vmemmap_pte_range(pmd, addr, next, walk);
+	} while (pmd++, addr = next, addr != end);
+
+	return 0;
+}
+
+static int vmemmap_pud_range(p4d_t *p4d, unsigned long addr,
+			     unsigned long end,
+			     struct vmemmap_remap_walk *walk)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	pud = pud_offset(p4d, addr);
+	do {
+		int ret;
+
+		next = pud_addr_end(addr, end);
+		ret = vmemmap_pmd_range(pud, addr, next, walk);
+		if (ret)
+			return ret;
+	} while (pud++, addr = next, addr != end);
+
+	return 0;
+}
+
+static int vmemmap_p4d_range(pgd_t *pgd, unsigned long addr,
+			     unsigned long end,
+			     struct vmemmap_remap_walk *walk)
+{
+	p4d_t *p4d;
+	unsigned long next;
+
+	p4d = p4d_offset(pgd, addr);
+	do {
+		int ret;
+
+		next = p4d_addr_end(addr, end);
+		ret = vmemmap_pud_range(p4d, addr, next, walk);
+		if (ret)
+			return ret;
+	} while (p4d++, addr = next, addr != end);
+
+	return 0;
+}
+
+static int vmemmap_remap_range(unsigned long start, unsigned long end,
+			       struct vmemmap_remap_walk *walk)
+{
+	unsigned long addr = start;
+	unsigned long next;
+	pgd_t *pgd;
+
+	VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
+	VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
+
+	pgd = pgd_offset_k(addr);
+	do {
+		int ret;
+
+		next = pgd_addr_end(addr, end);
+		ret = vmemmap_p4d_range(pgd, addr, next, walk);
+		if (ret)
+			return ret;
+	} while (pgd++, addr = next, addr != end);
+
+	/*
+	 * We only change the mapping of the vmemmap virtual address range
+	 * [@start + PAGE_SIZE, end), so we only need to flush the TLB which
+	 * belongs to the range.
+	 */
+	flush_tlb_kernel_range(start + PAGE_SIZE, end);
+
+	return 0;
+}
+
+/*
+ * Free a vmemmap page. A vmemmap page can be allocated from the memblock
+ * allocator or buddy allocator. If the PG_reserved flag is set, it means
+ * that it allocated from the memblock allocator, just free it via the
+ * free_bootmem_page(). Otherwise, use __free_page().
+ */
+static inline void free_vmemmap_page(struct page *page)
+{
+	if (PageReserved(page))
+		free_bootmem_page(page);
+	else
+		__free_page(page);
+}
+
+/* Free a list of the vmemmap pages */
+static void free_vmemmap_page_list(struct list_head *list)
+{
+	struct page *page, *next;
+
+	list_for_each_entry_safe(page, next, list, lru) {
+		list_del(&page->lru);
+		free_vmemmap_page(page);
+	}
+}
+
+static void vmemmap_remap_pte(pte_t *pte, unsigned long addr,
+			      struct vmemmap_remap_walk *walk)
+{
+	/*
+	 * Remap the tail pages as read-only to catch illegal write operation
+	 * to the tail pages.
+	 */
+	pgprot_t pgprot = PAGE_KERNEL_RO;
+	pte_t entry = mk_pte(walk->reuse_page, pgprot);
+	struct page *page = pte_page(*pte);
+
+	list_add_tail(&page->lru, walk->vmemmap_pages);
+	set_pte_at(&init_mm, addr, pte, entry);
+}
+
+static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
+				struct vmemmap_remap_walk *walk)
+{
+	pgprot_t pgprot = PAGE_KERNEL;
+	struct page *page;
+	void *to;
+
+	BUG_ON(pte_page(*pte) != walk->reuse_page);
+
+	page = list_first_entry(walk->vmemmap_pages, struct page, lru);
+	list_del(&page->lru);
+	to = page_to_virt(page);
+	copy_page(to, (void *)walk->reuse_addr);
+
+	set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot));
+}
+
+/**
+ * vmemmap_remap_free - remap the vmemmap virtual address range [@start, @end)
+ *			to the page which @reuse is mapped to, then free vmemmap
+ *			which the range are mapped to.
+ * @start:	start address of the vmemmap virtual address range that we want
+ *		to remap.
+ * @end:	end address of the vmemmap virtual address range that we want to
+ *		remap.
+ * @reuse:	reuse address.
+ *
+ * Return: %0 on success, negative error code otherwise.
+ */
+int vmemmap_remap_free(unsigned long start, unsigned long end,
+		       unsigned long reuse)
+{
+	int ret;
+	LIST_HEAD(vmemmap_pages);
+	struct vmemmap_remap_walk walk = {
+		.remap_pte	= vmemmap_remap_pte,
+		.reuse_addr	= reuse,
+		.vmemmap_pages	= &vmemmap_pages,
+	};
+
+	/*
+	 * In order to make remapping routine most efficient for the huge pages,
+	 * the routine of vmemmap page table walking has the following rules
+	 * (see more details from the vmemmap_pte_range()):
+	 *
+	 * - The range [@start, @end) and the range [@reuse, @reuse + PAGE_SIZE)
+	 *   should be continuous.
+	 * - The @reuse address is part of the range [@reuse, @end) that we are
+	 *   walking which is passed to vmemmap_remap_range().
+	 * - The @reuse address is the first in the complete range.
+	 *
+	 * So we need to make sure that @start and @reuse meet the above rules.
+	 */
+	BUG_ON(start - reuse != PAGE_SIZE);
+
+	mmap_write_lock(&init_mm);
+	ret = vmemmap_remap_range(reuse, end, &walk);
+	mmap_write_downgrade(&init_mm);
+
+	if (ret && walk.nr_walked) {
+		end = reuse + walk.nr_walked * PAGE_SIZE;
+		/*
+		 * vmemmap_pages contains pages from the previous
+		 * vmemmap_remap_range call which failed.  These
+		 * are pages which were removed from the vmemmap.
+		 * They will be restored in the following call.
+		 */
+		walk = (struct vmemmap_remap_walk) {
+			.remap_pte	= vmemmap_restore_pte,
+			.reuse_addr	= reuse,
+			.vmemmap_pages	= &vmemmap_pages,
+		};
+
+		vmemmap_remap_range(reuse, end, &walk);
+	}
+	mmap_read_unlock(&init_mm);
+
+	free_vmemmap_page_list(&vmemmap_pages);
+
+	return ret;
+}
+
+static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
+				   gfp_t gfp_mask, struct list_head *list)
+{
+	unsigned long nr_pages = (end - start) >> PAGE_SHIFT;
+	int nid = page_to_nid((struct page *)start);
+	struct page *page, *next;
+
+	while (nr_pages--) {
+		page = alloc_pages_node(nid, gfp_mask, 0);
+		if (!page)
+			goto out;
+		list_add_tail(&page->lru, list);
+	}
+
+	return 0;
+out:
+	list_for_each_entry_safe(page, next, list, lru)
+		__free_pages(page, 0);
+	return -ENOMEM;
+}
+
+/**
+ * vmemmap_remap_alloc - remap the vmemmap virtual address range [@start, end)
+ *			 to the page which is from the @vmemmap_pages
+ *			 respectively.
+ * @start:	start address of the vmemmap virtual address range that we want
+ *		to remap.
+ * @end:	end address of the vmemmap virtual address range that we want to
+ *		remap.
+ * @reuse:	reuse address.
+ * @gfp_mask:	GFP flag for allocating vmemmap pages.
+ *
+ * Return: %0 on success, negative error code otherwise.
+ */
+int vmemmap_remap_alloc(unsigned long start, unsigned long end,
+			unsigned long reuse, gfp_t gfp_mask)
+{
+	LIST_HEAD(vmemmap_pages);
+	struct vmemmap_remap_walk walk = {
+		.remap_pte	= vmemmap_restore_pte,
+		.reuse_addr	= reuse,
+		.vmemmap_pages	= &vmemmap_pages,
+	};
+
+	/* See the comment in the vmemmap_remap_free(). */
+	BUG_ON(start - reuse != PAGE_SIZE);
+
+	if (alloc_vmemmap_page_list(start, end, gfp_mask, &vmemmap_pages))
+		return -ENOMEM;
+
+	mmap_read_lock(&init_mm);
+	vmemmap_remap_range(reuse, end, &walk);
+	mmap_read_unlock(&init_mm);
+
+	return 0;
+}
 
 /*
  * Allocate a block of memory to be used to back the virtual memory map
diff --git a/mm/sparse.c b/mm/sparse.c
index 7272f7a1449d..6326cdf36c4f 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -13,6 +13,7 @@
 #include <linux/vmalloc.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
+#include <linux/bootmem_info.h>
 
 #include "internal.h"
 #include <asm/dma.h>
diff --git a/mm/swap.c b/mm/swap.c
index 6c11db780467..19600430e536 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -554,7 +554,7 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec)
 	} else {
 		/*
 		 * The page's writeback ends up during pagevec
-		 * We moves tha page into tail of inactive.
+		 * We move that page into tail of inactive.
 		 */
 		add_page_to_lru_list_tail(page, lruvec);
 		__count_vm_events(PGROTATED, nr_pages);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index e898c879a434..1e07d1c776f2 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2967,7 +2967,7 @@ static unsigned long read_swap_header(struct swap_info_struct *p,
 		return 0;
 	}
 
-	/* swap partition endianess hack... */
+	/* swap partition endianness hack... */
 	if (swab32(swap_header->info.version) == 1) {
 		swab32s(&swap_header->info.version);
 		swab32s(&swap_header->info.last_page);
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 63a73e164d55..0e2132834bc7 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -48,6 +48,78 @@ struct vm_area_struct *find_dst_vma(struct mm_struct *dst_mm,
 	return dst_vma;
 }
 
+/*
+ * Install PTEs, to map dst_addr (within dst_vma) to page.
+ *
+ * This function handles both MCOPY_ATOMIC_NORMAL and _CONTINUE for both shmem
+ * and anon, and for both shared and private VMAs.
+ */
+int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
+			     struct vm_area_struct *dst_vma,
+			     unsigned long dst_addr, struct page *page,
+			     bool newly_allocated, bool wp_copy)
+{
+	int ret;
+	pte_t _dst_pte, *dst_pte;
+	bool writable = dst_vma->vm_flags & VM_WRITE;
+	bool vm_shared = dst_vma->vm_flags & VM_SHARED;
+	bool page_in_cache = page->mapping;
+	spinlock_t *ptl;
+	struct inode *inode;
+	pgoff_t offset, max_off;
+
+	_dst_pte = mk_pte(page, dst_vma->vm_page_prot);
+	if (page_in_cache && !vm_shared)
+		writable = false;
+	if (writable || !page_in_cache)
+		_dst_pte = pte_mkdirty(_dst_pte);
+	if (writable) {
+		if (wp_copy)
+			_dst_pte = pte_mkuffd_wp(_dst_pte);
+		else
+			_dst_pte = pte_mkwrite(_dst_pte);
+	}
+
+	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
+
+	if (vma_is_shmem(dst_vma)) {
+		/* serialize against truncate with the page table lock */
+		inode = dst_vma->vm_file->f_inode;
+		offset = linear_page_index(dst_vma, dst_addr);
+		max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+		ret = -EFAULT;
+		if (unlikely(offset >= max_off))
+			goto out_unlock;
+	}
+
+	ret = -EEXIST;
+	if (!pte_none(*dst_pte))
+		goto out_unlock;
+
+	if (page_in_cache)
+		page_add_file_rmap(page, false);
+	else
+		page_add_new_anon_rmap(page, dst_vma, dst_addr, false);
+
+	/*
+	 * Must happen after rmap, as mm_counter() checks mapping (via
+	 * PageAnon()), which is set by __page_set_anon_rmap().
+	 */
+	inc_mm_counter(dst_mm, mm_counter(page));
+
+	if (newly_allocated)
+		lru_cache_add_inactive_or_unevictable(page, dst_vma);
+
+	set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+
+	/* No need to invalidate - it was non-present before */
+	update_mmu_cache(dst_vma, dst_addr, dst_pte);
+	ret = 0;
+out_unlock:
+	pte_unmap_unlock(dst_pte, ptl);
+	return ret;
+}
+
 static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    pmd_t *dst_pmd,
 			    struct vm_area_struct *dst_vma,
@@ -56,13 +128,9 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    struct page **pagep,
 			    bool wp_copy)
 {
-	pte_t _dst_pte, *dst_pte;
-	spinlock_t *ptl;
 	void *page_kaddr;
 	int ret;
 	struct page *page;
-	pgoff_t offset, max_off;
-	struct inode *inode;
 
 	if (!*pagep) {
 		ret = -ENOMEM;
@@ -99,43 +167,12 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 	if (mem_cgroup_charge(page, dst_mm, GFP_KERNEL))
 		goto out_release;
 
-	_dst_pte = pte_mkdirty(mk_pte(page, dst_vma->vm_page_prot));
-	if (dst_vma->vm_flags & VM_WRITE) {
-		if (wp_copy)
-			_dst_pte = pte_mkuffd_wp(_dst_pte);
-		else
-			_dst_pte = pte_mkwrite(_dst_pte);
-	}
-
-	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
-	if (dst_vma->vm_file) {
-		/* the shmem MAP_PRIVATE case requires checking the i_size */
-		inode = dst_vma->vm_file->f_inode;
-		offset = linear_page_index(dst_vma, dst_addr);
-		max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
-		ret = -EFAULT;
-		if (unlikely(offset >= max_off))
-			goto out_release_uncharge_unlock;
-	}
-	ret = -EEXIST;
-	if (!pte_none(*dst_pte))
-		goto out_release_uncharge_unlock;
-
-	inc_mm_counter(dst_mm, MM_ANONPAGES);
-	page_add_new_anon_rmap(page, dst_vma, dst_addr, false);
-	lru_cache_add_inactive_or_unevictable(page, dst_vma);
-
-	set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
-
-	/* No need to invalidate - it was non-present before */
-	update_mmu_cache(dst_vma, dst_addr, dst_pte);
-
-	pte_unmap_unlock(dst_pte, ptl);
-	ret = 0;
+	ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
+				       page, true, wp_copy);
+	if (ret)
+		goto out_release;
 out:
 	return ret;
-out_release_uncharge_unlock:
-	pte_unmap_unlock(dst_pte, ptl);
 out_release:
 	put_page(page);
 	goto out;
@@ -176,6 +213,41 @@ out_unlock:
 	return ret;
 }
 
+/* Handles UFFDIO_CONTINUE for all shmem VMAs (shared or private). */
+static int mcontinue_atomic_pte(struct mm_struct *dst_mm,
+				pmd_t *dst_pmd,
+				struct vm_area_struct *dst_vma,
+				unsigned long dst_addr,
+				bool wp_copy)
+{
+	struct inode *inode = file_inode(dst_vma->vm_file);
+	pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
+	struct page *page;
+	int ret;
+
+	ret = shmem_getpage(inode, pgoff, &page, SGP_READ);
+	if (ret)
+		goto out;
+	if (!page) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
+				       page, false, wp_copy);
+	if (ret)
+		goto out_release;
+
+	unlock_page(page);
+	ret = 0;
+out:
+	return ret;
+out_release:
+	unlock_page(page);
+	put_page(page);
+	goto out;
+}
+
 static pmd_t *mm_alloc_pmd(struct mm_struct *mm, unsigned long address)
 {
 	pgd_t *pgd;
@@ -209,7 +281,6 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 					      unsigned long len,
 					      enum mcopy_atomic_mode mode)
 {
-	int vm_alloc_shared = dst_vma->vm_flags & VM_SHARED;
 	int vm_shared = dst_vma->vm_flags & VM_SHARED;
 	ssize_t err;
 	pte_t *dst_pte;
@@ -308,7 +379,6 @@ retry:
 
 		mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 		i_mmap_unlock_read(mapping);
-		vm_alloc_shared = vm_shared;
 
 		cond_resched();
 
@@ -346,54 +416,8 @@ retry:
 out_unlock:
 	mmap_read_unlock(dst_mm);
 out:
-	if (page) {
-		/*
-		 * We encountered an error and are about to free a newly
-		 * allocated huge page.
-		 *
-		 * Reservation handling is very subtle, and is different for
-		 * private and shared mappings.  See the routine
-		 * restore_reserve_on_error for details.  Unfortunately, we
-		 * can not call restore_reserve_on_error now as it would
-		 * require holding mmap_lock.
-		 *
-		 * If a reservation for the page existed in the reservation
-		 * map of a private mapping, the map was modified to indicate
-		 * the reservation was consumed when the page was allocated.
-		 * We clear the HPageRestoreReserve flag now so that the global
-		 * reserve count will not be incremented in free_huge_page.
-		 * The reservation map will still indicate the reservation
-		 * was consumed and possibly prevent later page allocation.
-		 * This is better than leaking a global reservation.  If no
-		 * reservation existed, it is still safe to clear
-		 * HPageRestoreReserve as no adjustments to reservation counts
-		 * were made during allocation.
-		 *
-		 * The reservation map for shared mappings indicates which
-		 * pages have reservations.  When a huge page is allocated
-		 * for an address with a reservation, no change is made to
-		 * the reserve map.  In this case HPageRestoreReserve will be
-		 * set to indicate that the global reservation count should be
-		 * incremented when the page is freed.  This is the desired
-		 * behavior.  However, when a huge page is allocated for an
-		 * address without a reservation a reservation entry is added
-		 * to the reservation map, and HPageRestoreReserve will not be
-		 * set. When the page is freed, the global reserve count will
-		 * NOT be incremented and it will appear as though we have
-		 * leaked reserved page.  In this case, set HPageRestoreReserve
-		 * so that the global reserve count will be incremented to
-		 * match the reservation map entry which was created.
-		 *
-		 * Note that vm_alloc_shared is based on the flags of the vma
-		 * for which the page was originally allocated.  dst_vma could
-		 * be different or NULL on error.
-		 */
-		if (vm_alloc_shared)
-			SetHPageRestoreReserve(page);
-		else
-			ClearHPageRestoreReserve(page);
+	if (page)
 		put_page(page);
-	}
 	BUG_ON(copied < 0);
 	BUG_ON(err > 0);
 	BUG_ON(!copied && !err);
@@ -415,11 +439,16 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
 						unsigned long dst_addr,
 						unsigned long src_addr,
 						struct page **page,
-						bool zeropage,
+						enum mcopy_atomic_mode mode,
 						bool wp_copy)
 {
 	ssize_t err;
 
+	if (mode == MCOPY_ATOMIC_CONTINUE) {
+		return mcontinue_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
+					    wp_copy);
+	}
+
 	/*
 	 * The normal page fault path for a shmem will invoke the
 	 * fault, fill the hole in the file and COW it right away. The
@@ -431,7 +460,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
 	 * and not in the radix tree.
 	 */
 	if (!(dst_vma->vm_flags & VM_SHARED)) {
-		if (!zeropage)
+		if (mode == MCOPY_ATOMIC_NORMAL)
 			err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma,
 					       dst_addr, src_addr, page,
 					       wp_copy);
@@ -440,13 +469,10 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
 						 dst_vma, dst_addr);
 	} else {
 		VM_WARN_ON_ONCE(wp_copy);
-		if (!zeropage)
-			err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd,
-						     dst_vma, dst_addr,
-						     src_addr, page);
-		else
-			err = shmem_mfill_zeropage_pte(dst_mm, dst_pmd,
-						       dst_vma, dst_addr);
+		err = shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma,
+					     dst_addr, src_addr,
+					     mode != MCOPY_ATOMIC_NORMAL,
+					     page);
 	}
 
 	return err;
@@ -467,7 +493,6 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 	long copied;
 	struct page *page;
 	bool wp_copy;
-	bool zeropage = (mcopy_mode == MCOPY_ATOMIC_ZEROPAGE);
 
 	/*
 	 * Sanitize the command parameters:
@@ -530,7 +555,7 @@ retry:
 
 	if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma))
 		goto out_unlock;
-	if (mcopy_mode == MCOPY_ATOMIC_CONTINUE)
+	if (!vma_is_shmem(dst_vma) && mcopy_mode == MCOPY_ATOMIC_CONTINUE)
 		goto out_unlock;
 
 	/*
@@ -578,7 +603,7 @@ retry:
 		BUG_ON(pmd_trans_huge(*dst_pmd));
 
 		err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
-				       src_addr, &page, zeropage, wp_copy);
+				       src_addr, &page, mcopy_mode, wp_copy);
 		cond_resched();
 
 		if (unlikely(err == -ENOENT)) {
diff --git a/mm/util.c b/mm/util.c
index a8bf17f18a81..a034525e7ba2 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -1010,3 +1010,43 @@ void mem_dump_obj(void *object)
 }
 EXPORT_SYMBOL_GPL(mem_dump_obj);
 #endif
+
+/*
+ * A driver might set a page logically offline -- PageOffline() -- and
+ * turn the page inaccessible in the hypervisor; after that, access to page
+ * content can be fatal.
+ *
+ * Some special PFN walkers -- i.e., /proc/kcore -- read content of random
+ * pages after checking PageOffline(); however, these PFN walkers can race
+ * with drivers that set PageOffline().
+ *
+ * page_offline_freeze()/page_offline_thaw() allows for a subsystem to
+ * synchronize with such drivers, achieving that a page cannot be set
+ * PageOffline() while frozen.
+ *
+ * page_offline_begin()/page_offline_end() is used by drivers that care about
+ * such races when setting a page PageOffline().
+ */
+static DECLARE_RWSEM(page_offline_rwsem);
+
+void page_offline_freeze(void)
+{
+	down_read(&page_offline_rwsem);
+}
+
+void page_offline_thaw(void)
+{
+	up_read(&page_offline_rwsem);
+}
+
+void page_offline_begin(void)
+{
+	down_write(&page_offline_rwsem);
+}
+EXPORT_SYMBOL(page_offline_begin);
+
+void page_offline_end(void)
+{
+	up_write(&page_offline_rwsem);
+}
+EXPORT_SYMBOL(page_offline_end);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index b2ec7f751bd0..d5cd52805149 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -25,6 +25,7 @@
 #include <linux/notifier.h>
 #include <linux/rbtree.h>
 #include <linux/xarray.h>
+#include <linux/io.h>
 #include <linux/rcupdate.h>
 #include <linux/pfn.h>
 #include <linux/kmemleak.h>
@@ -36,6 +37,7 @@
 #include <linux/overflow.h>
 #include <linux/pgtable.h>
 #include <linux/uaccess.h>
+#include <linux/hugetlb.h>
 #include <asm/tlbflush.h>
 #include <asm/shmparam.h>
 
@@ -83,10 +85,11 @@ static void free_work(struct work_struct *w)
 /*** Page table manipulation functions ***/
 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 			phys_addr_t phys_addr, pgprot_t prot,
-			pgtbl_mod_mask *mask)
+			unsigned int max_page_shift, pgtbl_mod_mask *mask)
 {
 	pte_t *pte;
 	u64 pfn;
+	unsigned long size = PAGE_SIZE;
 
 	pfn = phys_addr >> PAGE_SHIFT;
 	pte = pte_alloc_kernel_track(pmd, addr, mask);
@@ -94,9 +97,22 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 		return -ENOMEM;
 	do {
 		BUG_ON(!pte_none(*pte));
+
+#ifdef CONFIG_HUGETLB_PAGE
+		size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
+		if (size != PAGE_SIZE) {
+			pte_t entry = pfn_pte(pfn, prot);
+
+			entry = pte_mkhuge(entry);
+			entry = arch_make_huge_pte(entry, ilog2(size), 0);
+			set_huge_pte_at(&init_mm, addr, pte, entry);
+			pfn += PFN_DOWN(size);
+			continue;
+		}
+#endif
 		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
 		pfn++;
-	} while (pte++, addr += PAGE_SIZE, addr != end);
+	} while (pte += PFN_DOWN(size), addr += size, addr != end);
 	*mask |= PGTBL_PTE_MODIFIED;
 	return 0;
 }
@@ -145,7 +161,7 @@ static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
 			continue;
 		}
 
-		if (vmap_pte_range(pmd, addr, next, phys_addr, prot, mask))
+		if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
 			return -ENOMEM;
 	} while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
 	return 0;
@@ -1592,6 +1608,7 @@ static DEFINE_MUTEX(vmap_purge_lock);
 /* for per-CPU blocks */
 static void purge_fragmented_blocks_allcpus(void);
 
+#ifdef CONFIG_X86_64
 /*
  * called before a call to iounmap() if the caller wants vm_area_struct's
  * immediately freed.
@@ -1600,6 +1617,7 @@ void set_iounmap_nonlazy(void)
 {
 	atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1);
 }
+#endif /* CONFIG_X86_64 */
 
 /*
  * Purges all lazily-freed vmap areas.
@@ -2912,8 +2930,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 		return NULL;
 	}
 
-	if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP) &&
-			arch_vmap_pmd_supported(prot)) {
+	if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
 		unsigned long size_per_node;
 
 		/*
@@ -2926,11 +2943,13 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 		size_per_node = size;
 		if (node == NUMA_NO_NODE)
 			size_per_node /= num_online_nodes();
-		if (size_per_node >= PMD_SIZE) {
+		if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
 			shift = PMD_SHIFT;
-			align = max(real_align, 1UL << shift);
-			size = ALIGN(real_size, 1UL << shift);
-		}
+		else
+			shift = arch_vmap_pte_supported_shift(size_per_node);
+
+		align = max(real_align, 1UL << shift);
+		size = ALIGN(real_size, 1UL << shift);
 	}
 
 again:
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d7c3cb8688dd..4620df62f0ff 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1499,7 +1499,8 @@ static unsigned int shrink_page_list(struct list_head *page_list,
 			if (unlikely(PageTransHuge(page)))
 				flags |= TTU_SPLIT_HUGE_PMD;
 
-			if (!try_to_unmap(page, flags)) {
+			try_to_unmap(page, flags);
+			if (page_mapped(page)) {
 				stat->nr_unmap_fail += nr_pages;
 				if (!was_swapbacked && PageSwapBacked(page))
 					stat->nr_lazyfree_fail += nr_pages;
@@ -1701,6 +1702,7 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 	unsigned int nr_reclaimed;
 	struct page *page, *next;
 	LIST_HEAD(clean_pages);
+	unsigned int noreclaim_flag;
 
 	list_for_each_entry_safe(page, next, page_list, lru) {
 		if (!PageHuge(page) && page_is_file_lru(page) &&
@@ -1711,8 +1713,17 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 		}
 	}
 
+	/*
+	 * We should be safe here since we are only dealing with file pages and
+	 * we are not kswapd and therefore cannot write dirty file pages. But
+	 * call memalloc_noreclaim_save() anyway, just in case these conditions
+	 * change in the future.
+	 */
+	noreclaim_flag = memalloc_noreclaim_save();
 	nr_reclaimed = shrink_page_list(&clean_pages, zone->zone_pgdat, &sc,
 					&stat, true);
+	memalloc_noreclaim_restore(noreclaim_flag);
+
 	list_splice(&clean_pages, page_list);
 	mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE,
 			    -(long)nr_reclaimed);
@@ -1810,7 +1821,7 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec,
 
 }
 
-/**
+/*
  * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
  *
  * lruvec->lru_lock is heavily contended.  Some of the functions that
@@ -2306,6 +2317,7 @@ unsigned long reclaim_pages(struct list_head *page_list)
 	LIST_HEAD(node_page_list);
 	struct reclaim_stat dummy_stat;
 	struct page *page;
+	unsigned int noreclaim_flag;
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
 		.priority = DEF_PRIORITY,
@@ -2314,6 +2326,8 @@ unsigned long reclaim_pages(struct list_head *page_list)
 		.may_swap = 1,
 	};
 
+	noreclaim_flag = memalloc_noreclaim_save();
+
 	while (!list_empty(page_list)) {
 		page = lru_to_page(page_list);
 		if (nid == NUMA_NO_NODE) {
@@ -2350,6 +2364,8 @@ unsigned long reclaim_pages(struct list_head *page_list)
 		}
 	}
 
+	memalloc_noreclaim_restore(noreclaim_flag);
+
 	return nr_reclaimed;
 }
 
diff --git a/mm/workingset.c b/mm/workingset.c
index 4f7a306ce75a..5ba3e42446fa 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -168,8 +168,10 @@
  * refault distance will immediately activate the refaulting page.
  */
 
+#define WORKINGSET_SHIFT 1
 #define EVICTION_SHIFT	((BITS_PER_LONG - BITS_PER_XA_VALUE) +	\
-			 1 + NODES_SHIFT + MEM_CGROUP_ID_SHIFT)
+			 WORKINGSET_SHIFT + NODES_SHIFT + \
+			 MEM_CGROUP_ID_SHIFT)
 #define EVICTION_MASK	(~0UL >> EVICTION_SHIFT)
 
 /*
@@ -189,7 +191,7 @@ static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction,
 	eviction &= EVICTION_MASK;
 	eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid;
 	eviction = (eviction << NODES_SHIFT) | pgdat->node_id;
-	eviction = (eviction << 1) | workingset;
+	eviction = (eviction << WORKINGSET_SHIFT) | workingset;
 
 	return xa_mk_value(eviction);
 }
@@ -201,8 +203,8 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
 	int memcgid, nid;
 	bool workingset;
 
-	workingset = entry & 1;
-	entry >>= 1;
+	workingset = entry & ((1UL << WORKINGSET_SHIFT) - 1);
+	entry >>= WORKINGSET_SHIFT;
 	nid = entry & ((1UL << NODES_SHIFT) - 1);
 	entry >>= NODES_SHIFT;
 	memcgid = entry & ((1UL << MEM_CGROUP_ID_SHIFT) - 1);
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 7fe7adaaad01..b3c0577b8095 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -62,7 +62,7 @@
 #define ZHDR_SIZE_ALIGNED round_up(sizeof(struct z3fold_header), CHUNK_SIZE)
 #define ZHDR_CHUNKS	(ZHDR_SIZE_ALIGNED >> CHUNK_SHIFT)
 #define TOTAL_CHUNKS	(PAGE_SIZE >> CHUNK_SHIFT)
-#define NCHUNKS		((PAGE_SIZE - ZHDR_SIZE_ALIGNED) >> CHUNK_SHIFT)
+#define NCHUNKS		(TOTAL_CHUNKS - ZHDR_CHUNKS)
 
 #define BUDDY_MASK	(0x3)
 #define BUDDY_SHIFT	2
@@ -144,6 +144,8 @@ struct z3fold_header {
  * @c_handle:	cache for z3fold_buddy_slots allocation
  * @ops:	pointer to a structure of user defined operations specified at
  *		pool creation time.
+ * @zpool:	zpool driver
+ * @zpool_ops:	zpool operations structure with an evict callback
  * @compact_wq:	workqueue for page layout background optimization
  * @release_wq:	workqueue for safe page release
  * @work:	work_struct for safe page release
@@ -253,9 +255,8 @@ static inline void z3fold_page_unlock(struct z3fold_header *zhdr)
 	spin_unlock(&zhdr->page_lock);
 }
 
-
-static inline struct z3fold_header *__get_z3fold_header(unsigned long handle,
-							bool lock)
+/* return locked z3fold page if it's not headless */
+static inline struct z3fold_header *get_z3fold_header(unsigned long handle)
 {
 	struct z3fold_buddy_slots *slots;
 	struct z3fold_header *zhdr;
@@ -269,13 +270,12 @@ static inline struct z3fold_header *__get_z3fold_header(unsigned long handle,
 			read_lock(&slots->lock);
 			addr = *(unsigned long *)handle;
 			zhdr = (struct z3fold_header *)(addr & PAGE_MASK);
-			if (lock)
-				locked = z3fold_page_trylock(zhdr);
+			locked = z3fold_page_trylock(zhdr);
 			read_unlock(&slots->lock);
 			if (locked)
 				break;
 			cpu_relax();
-		} while (lock);
+		} while (true);
 	} else {
 		zhdr = (struct z3fold_header *)(handle & PAGE_MASK);
 	}
@@ -283,18 +283,6 @@ static inline struct z3fold_header *__get_z3fold_header(unsigned long handle,
 	return zhdr;
 }
 
-/* Returns the z3fold page where a given handle is stored */
-static inline struct z3fold_header *handle_to_z3fold_header(unsigned long h)
-{
-	return __get_z3fold_header(h, false);
-}
-
-/* return locked z3fold page if it's not headless */
-static inline struct z3fold_header *get_z3fold_header(unsigned long h)
-{
-	return __get_z3fold_header(h, true);
-}
-
 static inline void put_z3fold_header(struct z3fold_header *zhdr)
 {
 	struct page *page = virt_to_page(zhdr);
@@ -998,7 +986,8 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp,
 		goto out_c;
 	spin_lock_init(&pool->lock);
 	spin_lock_init(&pool->stale_lock);
-	pool->unbuddied = __alloc_percpu(sizeof(struct list_head)*NCHUNKS, 2);
+	pool->unbuddied = __alloc_percpu(sizeof(struct list_head) * NCHUNKS,
+					 __alignof__(struct list_head));
 	if (!pool->unbuddied)
 		goto out_pool;
 	for_each_possible_cpu(cpu) {
@@ -1059,6 +1048,7 @@ static void z3fold_destroy_pool(struct z3fold_pool *pool)
 	destroy_workqueue(pool->compact_wq);
 	destroy_workqueue(pool->release_wq);
 	z3fold_unregister_migration(pool);
+	free_percpu(pool->unbuddied);
 	kfree(pool);
 }
 
@@ -1382,7 +1372,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
 			if (zhdr->foreign_handles ||
 			    test_and_set_bit(PAGE_CLAIMED, &page->private)) {
 				if (kref_put(&zhdr->refcount,
-						release_z3fold_page))
+						release_z3fold_page_locked))
 					atomic64_dec(&pool->pages_nr);
 				else
 					z3fold_page_unlock(zhdr);
@@ -1803,8 +1793,11 @@ static int __init init_z3fold(void)
 {
 	int ret;
 
-	/* Make sure the z3fold header is not larger than the page size */
-	BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE);
+	/*
+	 * Make sure the z3fold header is not larger than the page size and
+	 * there has remaining spaces for its buddy.
+	 */
+	BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE - CHUNK_SIZE);
 	ret = z3fold_mount();
 	if (ret)
 		return ret;
diff --git a/mm/zbud.c b/mm/zbud.c
index 7ec5f27a68b0..6348932430b8 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -51,7 +51,6 @@
 #include <linux/preempt.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
-#include <linux/zbud.h>
 #include <linux/zpool.h>
 
 /*****************
@@ -73,6 +72,12 @@
 #define ZHDR_SIZE_ALIGNED CHUNK_SIZE
 #define NCHUNKS		((PAGE_SIZE - ZHDR_SIZE_ALIGNED) >> CHUNK_SHIFT)
 
+struct zbud_pool;
+
+struct zbud_ops {
+	int (*evict)(struct zbud_pool *pool, unsigned long handle);
+};
+
 /**
  * struct zbud_pool - stores metadata for each zbud pool
  * @lock:	protects all pool fields and first|last_chunk fields of any
@@ -87,21 +92,27 @@
  * @pages_nr:	number of zbud pages in the pool.
  * @ops:	pointer to a structure of user defined operations specified at
  *		pool creation time.
+ * @zpool:	zpool driver
+ * @zpool_ops:	zpool operations structure with an evict callback
  *
  * This structure is allocated at pool creation time and maintains metadata
  * pertaining to a particular zbud pool.
  */
 struct zbud_pool {
 	spinlock_t lock;
-	struct list_head unbuddied[NCHUNKS];
-	struct list_head buddied;
+	union {
+		/*
+		 * Reuse unbuddied[0] as buddied on the ground that
+		 * unbuddied[0] is unused.
+		 */
+		struct list_head buddied;
+		struct list_head unbuddied[NCHUNKS];
+	};
 	struct list_head lru;
 	u64 pages_nr;
 	const struct zbud_ops *ops;
-#ifdef CONFIG_ZPOOL
 	struct zpool *zpool;
 	const struct zpool_ops *zpool_ops;
-#endif
 };
 
 /*
@@ -121,104 +132,6 @@ struct zbud_header {
 };
 
 /*****************
- * zpool
- ****************/
-
-#ifdef CONFIG_ZPOOL
-
-static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle)
-{
-	if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict)
-		return pool->zpool_ops->evict(pool->zpool, handle);
-	else
-		return -ENOENT;
-}
-
-static const struct zbud_ops zbud_zpool_ops = {
-	.evict =	zbud_zpool_evict
-};
-
-static void *zbud_zpool_create(const char *name, gfp_t gfp,
-			       const struct zpool_ops *zpool_ops,
-			       struct zpool *zpool)
-{
-	struct zbud_pool *pool;
-
-	pool = zbud_create_pool(gfp, zpool_ops ? &zbud_zpool_ops : NULL);
-	if (pool) {
-		pool->zpool = zpool;
-		pool->zpool_ops = zpool_ops;
-	}
-	return pool;
-}
-
-static void zbud_zpool_destroy(void *pool)
-{
-	zbud_destroy_pool(pool);
-}
-
-static int zbud_zpool_malloc(void *pool, size_t size, gfp_t gfp,
-			unsigned long *handle)
-{
-	return zbud_alloc(pool, size, gfp, handle);
-}
-static void zbud_zpool_free(void *pool, unsigned long handle)
-{
-	zbud_free(pool, handle);
-}
-
-static int zbud_zpool_shrink(void *pool, unsigned int pages,
-			unsigned int *reclaimed)
-{
-	unsigned int total = 0;
-	int ret = -EINVAL;
-
-	while (total < pages) {
-		ret = zbud_reclaim_page(pool, 8);
-		if (ret < 0)
-			break;
-		total++;
-	}
-
-	if (reclaimed)
-		*reclaimed = total;
-
-	return ret;
-}
-
-static void *zbud_zpool_map(void *pool, unsigned long handle,
-			enum zpool_mapmode mm)
-{
-	return zbud_map(pool, handle);
-}
-static void zbud_zpool_unmap(void *pool, unsigned long handle)
-{
-	zbud_unmap(pool, handle);
-}
-
-static u64 zbud_zpool_total_size(void *pool)
-{
-	return zbud_get_pool_size(pool) * PAGE_SIZE;
-}
-
-static struct zpool_driver zbud_zpool_driver = {
-	.type =		"zbud",
-	.sleep_mapped = true,
-	.owner =	THIS_MODULE,
-	.create =	zbud_zpool_create,
-	.destroy =	zbud_zpool_destroy,
-	.malloc =	zbud_zpool_malloc,
-	.free =		zbud_zpool_free,
-	.shrink =	zbud_zpool_shrink,
-	.map =		zbud_zpool_map,
-	.unmap =	zbud_zpool_unmap,
-	.total_size =	zbud_zpool_total_size,
-};
-
-MODULE_ALIAS("zpool-zbud");
-#endif /* CONFIG_ZPOOL */
-
-/*****************
  * Helpers
 *****************/
 /* Just to make the code easier to read */
@@ -304,7 +217,7 @@ static int num_free_chunks(struct zbud_header *zhdr)
  * Return: pointer to the new zbud pool or NULL if the metadata allocation
  * failed.
  */
-struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops)
+static struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops)
 {
 	struct zbud_pool *pool;
 	int i;
@@ -328,7 +241,7 @@ struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops)
  *
  * The pool should be emptied before this function is called.
  */
-void zbud_destroy_pool(struct zbud_pool *pool)
+static void zbud_destroy_pool(struct zbud_pool *pool)
 {
 	kfree(pool);
 }
@@ -352,7 +265,7 @@ void zbud_destroy_pool(struct zbud_pool *pool)
  * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
  * a new page.
  */
-int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
+static int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
 			unsigned long *handle)
 {
 	int chunks, i, freechunks;
@@ -427,7 +340,7 @@ found:
  * only sets the first|last_chunks to 0.  The page is actually freed
  * once both buddies are evicted (see zbud_reclaim_page() below).
  */
-void zbud_free(struct zbud_pool *pool, unsigned long handle)
+static void zbud_free(struct zbud_pool *pool, unsigned long handle)
 {
 	struct zbud_header *zhdr;
 	int freechunks;
@@ -499,7 +412,7 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle)
  * no pages to evict or an eviction handler is not registered, -EAGAIN if
  * the retry limit was hit.
  */
-int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
+static int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
 {
 	int i, ret, freechunks;
 	struct zbud_header *zhdr;
@@ -581,7 +494,7 @@ next:
  *
  * Returns: a pointer to the mapped allocation
  */
-void *zbud_map(struct zbud_pool *pool, unsigned long handle)
+static void *zbud_map(struct zbud_pool *pool, unsigned long handle)
 {
 	return (void *)(handle);
 }
@@ -591,7 +504,7 @@ void *zbud_map(struct zbud_pool *pool, unsigned long handle)
  * @pool:	pool in which the allocation resides
  * @handle:	handle associated with the allocation to be unmapped
  */
-void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
+static void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
 {
 }
 
@@ -602,30 +515,120 @@ void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
  * Returns: size in pages of the given pool.  The pool lock need not be
  * taken to access pages_nr.
  */
-u64 zbud_get_pool_size(struct zbud_pool *pool)
+static u64 zbud_get_pool_size(struct zbud_pool *pool)
 {
 	return pool->pages_nr;
 }
 
+/*****************
+ * zpool
+ ****************/
+
+static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle)
+{
+	if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict)
+		return pool->zpool_ops->evict(pool->zpool, handle);
+	else
+		return -ENOENT;
+}
+
+static const struct zbud_ops zbud_zpool_ops = {
+	.evict =	zbud_zpool_evict
+};
+
+static void *zbud_zpool_create(const char *name, gfp_t gfp,
+			       const struct zpool_ops *zpool_ops,
+			       struct zpool *zpool)
+{
+	struct zbud_pool *pool;
+
+	pool = zbud_create_pool(gfp, zpool_ops ? &zbud_zpool_ops : NULL);
+	if (pool) {
+		pool->zpool = zpool;
+		pool->zpool_ops = zpool_ops;
+	}
+	return pool;
+}
+
+static void zbud_zpool_destroy(void *pool)
+{
+	zbud_destroy_pool(pool);
+}
+
+static int zbud_zpool_malloc(void *pool, size_t size, gfp_t gfp,
+			unsigned long *handle)
+{
+	return zbud_alloc(pool, size, gfp, handle);
+}
+static void zbud_zpool_free(void *pool, unsigned long handle)
+{
+	zbud_free(pool, handle);
+}
+
+static int zbud_zpool_shrink(void *pool, unsigned int pages,
+			unsigned int *reclaimed)
+{
+	unsigned int total = 0;
+	int ret = -EINVAL;
+
+	while (total < pages) {
+		ret = zbud_reclaim_page(pool, 8);
+		if (ret < 0)
+			break;
+		total++;
+	}
+
+	if (reclaimed)
+		*reclaimed = total;
+
+	return ret;
+}
+
+static void *zbud_zpool_map(void *pool, unsigned long handle,
+			enum zpool_mapmode mm)
+{
+	return zbud_map(pool, handle);
+}
+static void zbud_zpool_unmap(void *pool, unsigned long handle)
+{
+	zbud_unmap(pool, handle);
+}
+
+static u64 zbud_zpool_total_size(void *pool)
+{
+	return zbud_get_pool_size(pool) * PAGE_SIZE;
+}
+
+static struct zpool_driver zbud_zpool_driver = {
+	.type =		"zbud",
+	.sleep_mapped = true,
+	.owner =	THIS_MODULE,
+	.create =	zbud_zpool_create,
+	.destroy =	zbud_zpool_destroy,
+	.malloc =	zbud_zpool_malloc,
+	.free =		zbud_zpool_free,
+	.shrink =	zbud_zpool_shrink,
+	.map =		zbud_zpool_map,
+	.unmap =	zbud_zpool_unmap,
+	.total_size =	zbud_zpool_total_size,
+};
+
+MODULE_ALIAS("zpool-zbud");
+
 static int __init init_zbud(void)
 {
 	/* Make sure the zbud header will fit in one chunk */
 	BUILD_BUG_ON(sizeof(struct zbud_header) > ZHDR_SIZE_ALIGNED);
 	pr_info("loaded\n");
 
-#ifdef CONFIG_ZPOOL
 	zpool_register_driver(&zbud_zpool_driver);
-#endif
 
 	return 0;
 }
 
 static void __exit exit_zbud(void)
 {
-#ifdef CONFIG_ZPOOL
 	zpool_unregister_driver(&zbud_zpool_driver);
-#endif
-
 	pr_info("unloaded\n");
 }
 
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 19b563bc6c48..68e8831068f4 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1471,7 +1471,6 @@ static void obj_free(struct size_class *class, unsigned long obj)
 	unsigned int f_objidx;
 	void *vaddr;
 
-	obj &= ~OBJ_ALLOCATED_TAG;
 	obj_to_location(obj, &f_page, &f_objidx);
 	f_offset = (class->size * f_objidx) & ~PAGE_MASK;
 	zspage = get_zspage(f_page);
@@ -2163,7 +2162,7 @@ static void async_free_zspage(struct work_struct *work)
 		VM_BUG_ON(fullness != ZS_EMPTY);
 		class = pool->size_class[class_idx];
 		spin_lock(&class->lock);
-		__free_zspage(pool, pool->size_class[class_idx], zspage);
+		__free_zspage(pool, class, zspage);
 		spin_unlock(&class->lock);
 	}
 };
diff --git a/mm/zswap.c b/mm/zswap.c
index 20763267a219..7944e3e57e78 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -967,6 +967,13 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
 	spin_unlock(&tree->lock);
 	BUG_ON(offset != entry->offset);
 
+	src = (u8 *)zhdr + sizeof(struct zswap_header);
+	if (!zpool_can_sleep_mapped(pool)) {
+		memcpy(tmp, src, entry->length);
+		src = tmp;
+		zpool_unmap_handle(pool, handle);
+	}
+
 	/* try to allocate swap cache page */
 	switch (zswap_get_swap_cache_page(swpentry, &page)) {
 	case ZSWAP_SWAPCACHE_FAIL: /* no memory or invalidate happened */
@@ -982,17 +989,7 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
 	case ZSWAP_SWAPCACHE_NEW: /* page is locked */
 		/* decompress */
 		acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
-
 		dlen = PAGE_SIZE;
-		src = (u8 *)zhdr + sizeof(struct zswap_header);
-
-		if (!zpool_can_sleep_mapped(pool)) {
-
-			memcpy(tmp, src, entry->length);
-			src = tmp;
-
-			zpool_unmap_handle(pool, handle);
-		}
 
 		mutex_lock(acomp_ctx->mutex);
 		sg_init_one(&input, src, entry->length);
@@ -1203,7 +1200,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 		zswap_reject_alloc_fail++;
 		goto put_dstmem;
 	}
-	buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_RW);
+	buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_WO);
 	memcpy(buf, &zhdr, hlen);
 	memcpy(buf + hlen, dst, dlen);
 	zpool_unmap_handle(entry->pool->zpool, handle);
@@ -1427,18 +1424,11 @@ static int __init zswap_debugfs_init(void)
 
 	return 0;
 }
-
-static void __exit zswap_debugfs_exit(void)
-{
-	debugfs_remove_recursive(zswap_debugfs_root);
-}
 #else
 static int __init zswap_debugfs_init(void)
 {
 	return 0;
 }
-
-static void __exit zswap_debugfs_exit(void) { }
 #endif
 
 /*********************************