Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in
   add_to_avail_list")

 - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP. It
   also speeds up GUP handling of transparent hugepages.

 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").

 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").

 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").

 - xu xin has doe some work on KSM's handling of zero pages. These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support
   tracking KSM-placed zero-pages").

 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").

 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").

 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with
   UFFD").

 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").

 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").

 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").

 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").

 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").

 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap"). And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").

 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").

 - Baoquan He has converted some architectures to use the
   GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
   architectures to take GENERIC_IOREMAP way").

 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").

 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep"). Liam also developed some efficiency
   improvements ("Reduce preallocations for maple tree").

 - Cleanup and optimization to the secondary IOMMU TLB invalidation,
   from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").

 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").

 - Kemeng Shi provides some maintenance work on the compaction code
   ("Two minor cleanups for compaction").

 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
   most file-backed faults under the VMA lock").

 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").

 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").

 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").

 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").

 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").

 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").

 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").

 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").

 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").

 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
   memmap on memory feature on ppc64").

 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock
   migratetype").

 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").

 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").

 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").

 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").

 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").

 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").

 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").

 - pagetable handling cleanups from Matthew Wilcox ("New page table
   range API").

 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").

 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").

 - Matthew Wilcox has also done some maintenance work on the MM
   subsystem documentation ("Improve mm documentation").

* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
  maple_tree: shrink struct maple_tree
  maple_tree: clean up mas_wr_append()
  secretmem: convert page_is_secretmem() to folio_is_secretmem()
  nios2: fix flush_dcache_page() for usage from irq context
  hugetlb: add documentation for vma_kernel_pagesize()
  mm: add orphaned kernel-doc to the rst files.
  mm: fix clean_record_shared_mapping_range kernel-doc
  mm: fix get_mctgt_type() kernel-doc
  mm: fix kernel-doc warning from tlb_flush_rmaps()
  mm: remove enum page_entry_size
  mm: allow ->huge_fault() to be called without the mmap_lock held
  mm: move PMD_ORDER to pgtable.h
  mm: remove checks for pte_index
  memcg: remove duplication detection for mem_cgroup_uncharge_swap
  mm/huge_memory: work on folio->swap instead of page->private when splitting folio
  mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
  mm/swap: use dedicated entry for swap in folio
  mm/swap: stop using page->private on tail pages for THP_SWAP
  selftests/mm: fix WARNING comparing pointer to 0
  selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
  ...

2 files changed, 119 insertions, 62 deletions

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index b5e1bea9194c..099c4824dd8a 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -405,7 +405,6 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 		access = VM_WRITE;
 	if (access == VM_WRITE)
 		flags |= FAULT_FLAG_WRITE;
-#ifdef CONFIG_PER_VMA_LOCK
 	if (!(flags & FAULT_FLAG_USER))
 		goto lock_mmap;
 	vma = lock_vma_under_rcu(mm, address);
@@ -416,7 +415,8 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 		goto lock_mmap;
 	}
 	fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs);
-	vma_end_read(vma);
+	if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
+		vma_end_read(vma);
 	if (!(fault & VM_FAULT_RETRY)) {
 		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
 		if (likely(!(fault & VM_FAULT_ERROR)))
@@ -430,7 +430,6 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 		goto out;
 	}
 lock_mmap:
-#endif /* CONFIG_PER_VMA_LOCK */
 	mmap_read_lock(mm);
 
 	gmap = NULL;
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 66ab68db9842..07fc660a24aa 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -43,17 +43,17 @@ __initcall(page_table_register_sysctl);
 
 unsigned long *crst_table_alloc(struct mm_struct *mm)
 {
-	struct page *page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
 
-	if (!page)
+	if (!ptdesc)
 		return NULL;
-	arch_set_page_dat(page, CRST_ALLOC_ORDER);
-	return (unsigned long *) page_to_virt(page);
+	arch_set_page_dat(ptdesc_page(ptdesc), CRST_ALLOC_ORDER);
+	return (unsigned long *) ptdesc_to_virt(ptdesc);
 }
 
 void crst_table_free(struct mm_struct *mm, unsigned long *table)
 {
-	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+	pagetable_free(virt_to_ptdesc(table));
 }
 
 static void __crst_table_upgrade(void *arg)
@@ -140,21 +140,21 @@ static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
 
 struct page *page_table_alloc_pgste(struct mm_struct *mm)
 {
-	struct page *page;
+	struct ptdesc *ptdesc;
 	u64 *table;
 
-	page = alloc_page(GFP_KERNEL);
-	if (page) {
-		table = (u64 *)page_to_virt(page);
+	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
+	if (ptdesc) {
+		table = (u64 *)ptdesc_to_virt(ptdesc);
 		memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	}
-	return page;
+	return ptdesc_page(ptdesc);
 }
 
 void page_table_free_pgste(struct page *page)
 {
-	__free_page(page);
+	pagetable_free(page_ptdesc(page));
 }
 
 #endif /* CONFIG_PGSTE */
@@ -229,11 +229,20 @@ void page_table_free_pgste(struct page *page)
  * logic described above. Both AA bits are set to 1 to denote a 4KB-pgtable
  * while the PP bits are never used, nor such a page is added to or removed
  * from mm_context_t::pgtable_list.
+ *
+ * pte_free_defer() overrides those rules: it takes the page off pgtable_list,
+ * and prevents both 2K fragments from being reused. pte_free_defer() has to
+ * guarantee that its pgtable cannot be reused before the RCU grace period
+ * has elapsed (which page_table_free_rcu() does not actually guarantee).
+ * But for simplicity, because page->rcu_head overlays page->lru, and because
+ * the RCU callback might not be called before the mm_context_t has been freed,
+ * pte_free_defer() in this implementation prevents both fragments from being
+ * reused, and delays making the call to RCU until both fragments are freed.
  */
 unsigned long *page_table_alloc(struct mm_struct *mm)
 {
 	unsigned long *table;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	unsigned int mask, bit;
 
 	/* Try to get a fragment of a 4K page as a 2K page table */
@@ -241,9 +250,9 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 		table = NULL;
 		spin_lock_bh(&mm->context.lock);
 		if (!list_empty(&mm->context.pgtable_list)) {
-			page = list_first_entry(&mm->context.pgtable_list,
-						struct page, lru);
-			mask = atomic_read(&page->_refcount) >> 24;
+			ptdesc = list_first_entry(&mm->context.pgtable_list,
+						struct ptdesc, pt_list);
+			mask = atomic_read(&ptdesc->_refcount) >> 24;
 			/*
 			 * The pending removal bits must also be checked.
 			 * Failure to do so might lead to an impossible
@@ -255,13 +264,13 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 			 */
 			mask = (mask | (mask >> 4)) & 0x03U;
 			if (mask != 0x03U) {
-				table = (unsigned long *) page_to_virt(page);
+				table = (unsigned long *) ptdesc_to_virt(ptdesc);
 				bit = mask & 1;		/* =1 -> second 2K */
 				if (bit)
 					table += PTRS_PER_PTE;
-				atomic_xor_bits(&page->_refcount,
+				atomic_xor_bits(&ptdesc->_refcount,
 							0x01U << (bit + 24));
-				list_del(&page->lru);
+				list_del_init(&ptdesc->pt_list);
 			}
 		}
 		spin_unlock_bh(&mm->context.lock);
@@ -269,27 +278,28 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 			return table;
 	}
 	/* Allocate a fresh page */
-	page = alloc_page(GFP_KERNEL);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pte_page_ctor(page)) {
-		__free_page(page);
+	if (!pagetable_pte_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
-	arch_set_page_dat(page, 0);
+	arch_set_page_dat(ptdesc_page(ptdesc), 0);
 	/* Initialize page table */
-	table = (unsigned long *) page_to_virt(page);
+	table = (unsigned long *) ptdesc_to_virt(ptdesc);
 	if (mm_alloc_pgste(mm)) {
 		/* Return 4K page table with PGSTEs */
-		atomic_xor_bits(&page->_refcount, 0x03U << 24);
+		INIT_LIST_HEAD(&ptdesc->pt_list);
+		atomic_xor_bits(&ptdesc->_refcount, 0x03U << 24);
 		memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	} else {
 		/* Return the first 2K fragment of the page */
-		atomic_xor_bits(&page->_refcount, 0x01U << 24);
+		atomic_xor_bits(&ptdesc->_refcount, 0x01U << 24);
 		memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
 		spin_lock_bh(&mm->context.lock);
-		list_add(&page->lru, &mm->context.pgtable_list);
+		list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
 		spin_unlock_bh(&mm->context.lock);
 	}
 	return table;
@@ -300,7 +310,9 @@ static void page_table_release_check(struct page *page, void *table,
 {
 	char msg[128];
 
-	if (!IS_ENABLED(CONFIG_DEBUG_VM) || !mask)
+	if (!IS_ENABLED(CONFIG_DEBUG_VM))
+		return;
+	if (!mask && list_empty(&page->lru))
 		return;
 	snprintf(msg, sizeof(msg),
 		 "Invalid pgtable %p release half 0x%02x mask 0x%02x",
@@ -308,12 +320,20 @@ static void page_table_release_check(struct page *page, void *table,
 	dump_page(page, msg);
 }
 
+static void pte_free_now(struct rcu_head *head)
+{
+	struct ptdesc *ptdesc;
+
+	ptdesc = container_of(head, struct ptdesc, pt_rcu_head);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
+}
+
 void page_table_free(struct mm_struct *mm, unsigned long *table)
 {
 	unsigned int mask, bit, half;
-	struct page *page;
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
-	page = virt_to_page(table);
 	if (!mm_alloc_pgste(mm)) {
 		/* Free 2K page table fragment of a 4K page */
 		bit = ((unsigned long) table & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
@@ -323,42 +343,50 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
 		 * will happen outside of the critical section from this
 		 * function or from __tlb_remove_table()
 		 */
-		mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
+		mask = atomic_xor_bits(&ptdesc->_refcount, 0x11U << (bit + 24));
 		mask >>= 24;
-		if (mask & 0x03U)
-			list_add(&page->lru, &mm->context.pgtable_list);
-		else
-			list_del(&page->lru);
+		if ((mask & 0x03U) && !folio_test_active(ptdesc_folio(ptdesc))) {
+			/*
+			 * Other half is allocated, and neither half has had
+			 * its free deferred: add page to head of list, to make
+			 * this freed half available for immediate reuse.
+			 */
+			list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
+		} else {
+			/* If page is on list, now remove it. */
+			list_del_init(&ptdesc->pt_list);
+		}
 		spin_unlock_bh(&mm->context.lock);
-		mask = atomic_xor_bits(&page->_refcount, 0x10U << (bit + 24));
+		mask = atomic_xor_bits(&ptdesc->_refcount, 0x10U << (bit + 24));
 		mask >>= 24;
 		if (mask != 0x00U)
 			return;
 		half = 0x01U << bit;
 	} else {
 		half = 0x03U;
-		mask = atomic_xor_bits(&page->_refcount, 0x03U << 24);
+		mask = atomic_xor_bits(&ptdesc->_refcount, 0x03U << 24);
 		mask >>= 24;
 	}
 
-	page_table_release_check(page, table, half, mask);
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
+	if (folio_test_clear_active(ptdesc_folio(ptdesc)))
+		call_rcu(&ptdesc->pt_rcu_head, pte_free_now);
+	else
+		pte_free_now(&ptdesc->pt_rcu_head);
 }
 
 void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 			 unsigned long vmaddr)
 {
 	struct mm_struct *mm;
-	struct page *page;
 	unsigned int bit, mask;
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
 	mm = tlb->mm;
-	page = virt_to_page(table);
 	if (mm_alloc_pgste(mm)) {
 		gmap_unlink(mm, table, vmaddr);
 		table = (unsigned long *) ((unsigned long)table | 0x03U);
-		tlb_remove_table(tlb, table);
+		tlb_remove_ptdesc(tlb, table);
 		return;
 	}
 	bit = ((unsigned long) table & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
@@ -368,12 +396,20 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 	 * outside of the critical section from __tlb_remove_table() or from
 	 * page_table_free()
 	 */
-	mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
+	mask = atomic_xor_bits(&ptdesc->_refcount, 0x11U << (bit + 24));
 	mask >>= 24;
-	if (mask & 0x03U)
-		list_add_tail(&page->lru, &mm->context.pgtable_list);
-	else
-		list_del(&page->lru);
+	if ((mask & 0x03U) && !folio_test_active(ptdesc_folio(ptdesc))) {
+		/*
+		 * Other half is allocated, and neither half has had
+		 * its free deferred: add page to end of list, to make
+		 * this freed half available for reuse once its pending
+		 * bit has been cleared by __tlb_remove_table().
+		 */
+		list_add_tail(&ptdesc->pt_list, &mm->context.pgtable_list);
+	} else {
+		/* If page is on list, now remove it. */
+		list_del_init(&ptdesc->pt_list);
+	}
 	spin_unlock_bh(&mm->context.lock);
 	table = (unsigned long *) ((unsigned long) table | (0x01U << bit));
 	tlb_remove_table(tlb, table);
@@ -383,30 +419,48 @@ void __tlb_remove_table(void *_table)
 {
 	unsigned int mask = (unsigned long) _table & 0x03U, half = mask;
 	void *table = (void *)((unsigned long) _table ^ mask);
-	struct page *page = virt_to_page(table);
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
 	switch (half) {
 	case 0x00U:	/* pmd, pud, or p4d */
-		free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+		pagetable_free(ptdesc);
 		return;
 	case 0x01U:	/* lower 2K of a 4K page table */
 	case 0x02U:	/* higher 2K of a 4K page table */
-		mask = atomic_xor_bits(&page->_refcount, mask << (4 + 24));
+		mask = atomic_xor_bits(&ptdesc->_refcount, mask << (4 + 24));
 		mask >>= 24;
 		if (mask != 0x00U)
 			return;
 		break;
 	case 0x03U:	/* 4K page table with pgstes */
-		mask = atomic_xor_bits(&page->_refcount, 0x03U << 24);
+		mask = atomic_xor_bits(&ptdesc->_refcount, 0x03U << 24);
 		mask >>= 24;
 		break;
 	}
 
-	page_table_release_check(page, table, half, mask);
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
+	if (folio_test_clear_active(ptdesc_folio(ptdesc)))
+		call_rcu(&ptdesc->pt_rcu_head, pte_free_now);
+	else
+		pte_free_now(&ptdesc->pt_rcu_head);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void pte_free_defer(struct mm_struct *mm, pgtable_t pgtable)
+{
+	struct page *page;
+
+	page = virt_to_page(pgtable);
+	SetPageActive(page);
+	page_table_free(mm, (unsigned long *)pgtable);
+	/*
+	 * page_table_free() does not do the pgste gmap_unlink() which
+	 * page_table_free_rcu() does: warn us if pgste ever reaches here.
+	 */
+	WARN_ON_ONCE(mm_has_pgste(mm));
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
 /*
  * Base infrastructure required to generate basic asces, region, segment,
  * and page tables that do not make use of enhanced features like EDAT1.
@@ -432,16 +486,20 @@ static void base_pgt_free(unsigned long *table)
 static unsigned long *base_crst_alloc(unsigned long val)
 {
 	unsigned long *table;
+	struct ptdesc *ptdesc;
 
-	table =	(unsigned long *)__get_free_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
-	if (table)
-		crst_table_init(table, val);
+	ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, CRST_ALLOC_ORDER);
+	if (!ptdesc)
+		return NULL;
+	table = ptdesc_address(ptdesc);
+
+	crst_table_init(table, val);
 	return table;
 }
 
 static void base_crst_free(unsigned long *table)
 {
-	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+	pagetable_free(virt_to_ptdesc(table));
 }
 
 #define BASE_ADDR_END_FUNC(NAME, SIZE)					\