Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...

1 files changed, 11 insertions, 8 deletions

diff --git a/mm/swap_state.c b/mm/swap_state.c
index 7a003d8abb37..b76a65ac28b3 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -336,7 +336,7 @@ struct folio *swap_cache_get_folio(swp_entry_t entry,
 	struct folio *folio;
 
 	folio = filemap_get_folio(swap_address_space(entry), swp_offset(entry));
-	if (folio) {
+	if (!IS_ERR(folio)) {
 		bool vma_ra = swap_use_vma_readahead();
 		bool readahead;
 
@@ -366,6 +366,8 @@ struct folio *swap_cache_get_folio(swp_entry_t entry,
 			if (!vma || !vma_ra)
 				atomic_inc(&swapin_readahead_hits);
 		}
+	} else {
+		folio = NULL;
 	}
 
 	return folio;
@@ -386,25 +388,26 @@ struct folio *filemap_get_incore_folio(struct address_space *mapping,
 {
 	swp_entry_t swp;
 	struct swap_info_struct *si;
-	struct folio *folio = __filemap_get_folio(mapping, index, FGP_ENTRY, 0);
+	struct folio *folio = filemap_get_entry(mapping, index);
 
+	if (!folio)
+		return ERR_PTR(-ENOENT);
 	if (!xa_is_value(folio))
-		goto out;
+		return folio;
 	if (!shmem_mapping(mapping))
-		return NULL;
+		return ERR_PTR(-ENOENT);
 
 	swp = radix_to_swp_entry(folio);
 	/* There might be swapin error entries in shmem mapping. */
 	if (non_swap_entry(swp))
-		return NULL;
+		return ERR_PTR(-ENOENT);
 	/* Prevent swapoff from happening to us */
 	si = get_swap_device(swp);
 	if (!si)
-		return NULL;
+		return ERR_PTR(-ENOENT);
 	index = swp_offset(swp);
 	folio = filemap_get_folio(swap_address_space(swp), index);
 	put_swap_device(si);
-out:
 	return folio;
 }
 
@@ -431,7 +434,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		folio = filemap_get_folio(swap_address_space(entry),
 						swp_offset(entry));
 		put_swap_device(si);
-		if (folio)
+		if (!IS_ERR(folio))
 			return folio_file_page(folio, swp_offset(entry));
 
 		/*