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
  ...

4 files changed, 25 insertions, 22 deletions

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index b9fb1177fff6..859bc4e2c9b0 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -566,9 +566,9 @@ retry:
 	 * started */
 	folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
 			mapping_gfp_mask(mapping));
-	if (!folio) {
-		ret = -ENOMEM;
-		goto out;
+	if (IS_ERR(folio)) {
+		ret = PTR_ERR(folio);
+		goto out_nofolio;
 	}
 
 	ext4_write_lock_xattr(inode, &no_expand);
@@ -633,6 +633,7 @@ out:
 		folio_unlock(folio);
 		folio_put(folio);
 	}
+out_nofolio:
 	if (sem_held)
 		ext4_write_unlock_xattr(inode, &no_expand);
 	if (handle)
@@ -693,8 +694,8 @@ int ext4_try_to_write_inline_data(struct address_space *mapping,
 
 	folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
 					mapping_gfp_mask(mapping));
-	if (!folio) {
-		ret = -ENOMEM;
+	if (IS_ERR(folio)) {
+		ret = PTR_ERR(folio);
 		goto out;
 	}
 
@@ -854,8 +855,8 @@ static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping,
 
 	folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN,
 					mapping_gfp_mask(mapping));
-	if (!folio)
-		return -ENOMEM;
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
 
 	down_read(&EXT4_I(inode)->xattr_sem);
 	if (!ext4_has_inline_data(inode)) {
@@ -947,8 +948,8 @@ retry_journal:
 	 */
 	folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
 					mapping_gfp_mask(mapping));
-	if (!folio) {
-		ret = -ENOMEM;
+	if (IS_ERR(folio)) {
+		ret = PTR_ERR(folio);
 		goto out_journal;
 	}
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8dbd352e3986..ffbbd9626bd8 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1162,8 +1162,8 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
 retry_grab:
 	folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
 					mapping_gfp_mask(mapping));
-	if (!folio)
-		return -ENOMEM;
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
 	/*
 	 * The same as page allocation, we prealloc buffer heads before
 	 * starting the handle.
@@ -2906,8 +2906,8 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
 retry:
 	folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
 			mapping_gfp_mask(mapping));
-	if (!folio)
-		return -ENOMEM;
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
 
 	/* In case writeback began while the folio was unlocked */
 	folio_wait_stable(folio);
@@ -3618,8 +3618,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 	folio = __filemap_get_folio(mapping, from >> PAGE_SHIFT,
 				    FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
 				    mapping_gfp_constraint(mapping, ~__GFP_FS));
-	if (!folio)
-		return -ENOMEM;
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
 
 	blocksize = inode->i_sb->s_blocksize;
 
@@ -5201,7 +5201,7 @@ static void ext4_wait_for_tail_page_commit(struct inode *inode)
 	while (1) {
 		struct folio *folio = filemap_lock_folio(inode->i_mapping,
 				      inode->i_size >> PAGE_SHIFT);
-		if (!folio)
+		if (IS_ERR(folio))
 			return;
 		ret = __ext4_journalled_invalidate_folio(folio, offset,
 						folio_size(folio) - offset);
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index e509c22a21ed..b5af2fc03b2f 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -140,18 +140,18 @@ mext_folio_double_lock(struct inode *inode1, struct inode *inode2,
 	flags = memalloc_nofs_save();
 	folio[0] = __filemap_get_folio(mapping[0], index1, FGP_WRITEBEGIN,
 			mapping_gfp_mask(mapping[0]));
-	if (!folio[0]) {
+	if (IS_ERR(folio[0])) {
 		memalloc_nofs_restore(flags);
-		return -ENOMEM;
+		return PTR_ERR(folio[0]);
 	}
 
 	folio[1] = __filemap_get_folio(mapping[1], index2, FGP_WRITEBEGIN,
 			mapping_gfp_mask(mapping[1]));
 	memalloc_nofs_restore(flags);
-	if (!folio[1]) {
+	if (IS_ERR(folio[1])) {
 		folio_unlock(folio[0]);
 		folio_put(folio[0]);
-		return -ENOMEM;
+		return PTR_ERR(folio[1]);
 	}
 	/*
 	 * __filemap_get_folio() may not wait on folio's writeback if
diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index 3b01247066dd..2f37e1ea3955 100644
--- a/fs/ext4/verity.c
+++ b/fs/ext4/verity.c
@@ -366,14 +366,16 @@ static struct page *ext4_read_merkle_tree_page(struct inode *inode,
 	index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT;
 
 	folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);
-	if (!folio || !folio_test_uptodate(folio)) {
+	if (IS_ERR(folio) || !folio_test_uptodate(folio)) {
 		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
 
-		if (folio)
+		if (!IS_ERR(folio))
 			folio_put(folio);
 		else if (num_ra_pages > 1)
 			page_cache_ra_unbounded(&ractl, num_ra_pages, 0);
 		folio = read_mapping_folio(inode->i_mapping, index, NULL);
+		if (IS_ERR(folio))
+			return ERR_CAST(folio);
 	}
 	return folio_file_page(folio, index);
 }