Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - More userfaultfs work from Peter Xu

 - Several convert-to-folios series from Sidhartha Kumar and Huang Ying

 - Some filemap cleanups from Vishal Moola

 - David Hildenbrand added the ability to selftest anon memory COW
   handling

 - Some cpuset simplifications from Liu Shixin

 - Addition of vmalloc tracing support by Uladzislau Rezki

 - Some pagecache folioifications and simplifications from Matthew
   Wilcox

 - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use
   it

 - Miguel Ojeda contributed some cleanups for our use of the
   __no_sanitize_thread__ gcc keyword.

   This series should have been in the non-MM tree, my bad

 - Naoya Horiguchi improved the interaction between memory poisoning and
   memory section removal for huge pages

 - DAMON cleanups and tuneups from SeongJae Park

 - Tony Luck fixed the handling of COW faults against poisoned pages

 - Peter Xu utilized the PTE marker code for handling swapin errors

 - Hugh Dickins reworked compound page mapcount handling, simplifying it
   and making it more efficient

 - Removal of the autonuma savedwrite infrastructure from Nadav Amit and
   David Hildenbrand

 - zram support for multiple compression streams from Sergey Senozhatsky

 - David Hildenbrand reworked the GUP code's R/O long-term pinning so
   that drivers no longer need to use the FOLL_FORCE workaround which
   didn't work very well anyway

 - Mel Gorman altered the page allocator so that local IRQs can remnain
   enabled during per-cpu page allocations

 - Vishal Moola removed the try_to_release_page() wrapper

 - Stefan Roesch added some per-BDI sysfs tunables which are used to
   prevent network block devices from dirtying excessive amounts of
   pagecache

 - David Hildenbrand did some cleanup and repair work on KSM COW
   breaking

 - Nhat Pham and Johannes Weiner have implemented writeback in zswap's
   zsmalloc backend

 - Brian Foster has fixed a longstanding corner-case oddity in
   file[map]_write_and_wait_range()

 - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
   Chen

 - Shiyang Ruan has done some work on fsdax, to make its reflink mode
   work better under xfstests. Better, but still not perfect

 - Christoph Hellwig has removed the .writepage() method from several
   filesystems. They only need .writepages()

 - Yosry Ahmed wrote a series which fixes the memcg reclaim target
   beancounting

 - David Hildenbrand has fixed some of our MM selftests for 32-bit
   machines

 - Many singleton patches, as usual

* tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits)
  mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio
  mm: mmu_gather: allow more than one batch of delayed rmaps
  mm: fix typo in struct pglist_data code comment
  kmsan: fix memcpy tests
  mm: add cond_resched() in swapin_walk_pmd_entry()
  mm: do not show fs mm pc for VM_LOCKONFAULT pages
  selftests/vm: ksm_functional_tests: fixes for 32bit
  selftests/vm: cow: fix compile warning on 32bit
  selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions
  mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem
  mm,thp,rmap: fix races between updates of subpages_mapcount
  mm: memcg: fix swapcached stat accounting
  mm: add nodes= arg to memory.reclaim
  mm: disable top-tier fallback to reclaim on proactive reclaim
  selftests: cgroup: make sure reclaim target memcg is unprotected
  selftests: cgroup: refactor proactive reclaim code to reclaim_until()
  mm: memcg: fix stale protection of reclaim target memcg
  mm/mmap: properly unaccount memory on mas_preallocate() failure
  omfs: remove ->writepage
  jfs: remove ->writepage
  ...

1 files changed, 30 insertions, 27 deletions

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 3703a56571c1..5a7d2d5093f9 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1238,15 +1238,8 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
 		/*
 		 * Check if the page has any GUP (or other external) pins.
 		 *
-		 * Here the check is racy it may see total_mapcount > refcount
-		 * in some cases.
-		 * For example, one process with one forked child process.
-		 * The parent has the PMD split due to MADV_DONTNEED, then
-		 * the child is trying unmap the whole PMD, but khugepaged
-		 * may be scanning the parent between the child has
-		 * PageDoubleMap flag cleared and dec the mapcount.  So
-		 * khugepaged may see total_mapcount > refcount.
-		 *
+		 * Here the check may be racy:
+		 * it may see total_mapcount > refcount in some cases?
 		 * But such case is ephemeral we could always retry collapse
 		 * later.  However it may report false positive if the page
 		 * has excessive GUP pins (i.e. 512).  Anyway the same check
@@ -1751,12 +1744,12 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 {
 	struct address_space *mapping = file->f_mapping;
 	struct page *hpage;
-	pgoff_t index, end = start + HPAGE_PMD_NR;
+	pgoff_t index = 0, end = start + HPAGE_PMD_NR;
 	LIST_HEAD(pagelist);
 	XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER);
 	int nr_none = 0, result = SCAN_SUCCEED;
 	bool is_shmem = shmem_file(file);
-	int nr;
+	int nr = 0;
 
 	VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
 	VM_BUG_ON(start & (HPAGE_PMD_NR - 1));
@@ -1796,6 +1789,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 	xas_set(&xas, start);
 	for (index = start; index < end; index++) {
 		struct page *page = xas_next(&xas);
+		struct folio *folio;
 
 		VM_BUG_ON(index != xas.xa_index);
 		if (is_shmem) {
@@ -1822,8 +1816,6 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 			}
 
 			if (xa_is_value(page) || !PageUptodate(page)) {
-				struct folio *folio;
-
 				xas_unlock_irq(&xas);
 				/* swap in or instantiate fallocated page */
 				if (shmem_get_folio(mapping->host, index,
@@ -1911,13 +1903,15 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 			goto out_unlock;
 		}
 
-		if (page_mapping(page) != mapping) {
+		folio = page_folio(page);
+
+		if (folio_mapping(folio) != mapping) {
 			result = SCAN_TRUNCATED;
 			goto out_unlock;
 		}
 
-		if (!is_shmem && (PageDirty(page) ||
-				  PageWriteback(page))) {
+		if (!is_shmem && (folio_test_dirty(folio) ||
+				  folio_test_writeback(folio))) {
 			/*
 			 * khugepaged only works on read-only fd, so this
 			 * page is dirty because it hasn't been flushed
@@ -1927,20 +1921,20 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 			goto out_unlock;
 		}
 
-		if (isolate_lru_page(page)) {
+		if (folio_isolate_lru(folio)) {
 			result = SCAN_DEL_PAGE_LRU;
 			goto out_unlock;
 		}
 
-		if (page_has_private(page) &&
-		    !try_to_release_page(page, GFP_KERNEL)) {
+		if (folio_has_private(folio) &&
+		    !filemap_release_folio(folio, GFP_KERNEL)) {
 			result = SCAN_PAGE_HAS_PRIVATE;
-			putback_lru_page(page);
+			folio_putback_lru(folio);
 			goto out_unlock;
 		}
 
-		if (page_mapped(page))
-			try_to_unmap(page_folio(page),
+		if (folio_mapped(folio))
+			try_to_unmap(folio,
 					TTU_IGNORE_MLOCK | TTU_BATCH_FLUSH);
 
 		xas_lock_irq(&xas);
@@ -2019,6 +2013,7 @@ xa_unlocked:
 
 	if (result == SCAN_SUCCEED) {
 		struct page *page, *tmp;
+		struct folio *folio;
 
 		/*
 		 * Replacing old pages with new one has succeeded, now we
@@ -2046,11 +2041,13 @@ xa_unlocked:
 			index++;
 		}
 
-		SetPageUptodate(hpage);
-		page_ref_add(hpage, HPAGE_PMD_NR - 1);
+		folio = page_folio(hpage);
+		folio_mark_uptodate(folio);
+		folio_ref_add(folio, HPAGE_PMD_NR - 1);
+
 		if (is_shmem)
-			set_page_dirty(hpage);
-		lru_cache_add(hpage);
+			folio_mark_dirty(folio);
+		folio_add_lru(folio);
 
 		/*
 		 * Remove pte page tables, so we can re-fault the page as huge.
@@ -2108,7 +2105,8 @@ out:
 		mem_cgroup_uncharge(page_folio(hpage));
 		put_page(hpage);
 	}
-	/* TODO: tracepoints */
+
+	trace_mm_khugepaged_collapse_file(mm, hpage, index, is_shmem, addr, file, nr, result);
 	return result;
 }
 
@@ -2577,6 +2575,11 @@ void khugepaged_min_free_kbytes_update(void)
 	mutex_unlock(&khugepaged_mutex);
 }
 
+bool current_is_khugepaged(void)
+{
+	return kthread_func(current) == khugepaged;
+}
+
 static int madvise_collapse_errno(enum scan_result r)
 {
 	/*