10 hotfixes, 7 of which are cc:stable. 7 are MM, 3 are not. All

singletons.
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Merge tag 'mm-hotfixes-stable-2024-11-12-16-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "10 hotfixes, 7 of which are cc:stable. 7 are MM, 3 are not. All
  singletons"

* tag 'mm-hotfixes-stable-2024-11-12-16-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm: swapfile: fix cluster reclaim work crash on rotational devices
  selftests: hugetlb_dio: fixup check for initial conditions to skip in the start
  mm/thp: fix deferred split queue not partially_mapped: fix
  mm/gup: avoid an unnecessary allocation call for FOLL_LONGTERM cases
  nommu: pass NULL argument to vma_iter_prealloc()
  ocfs2: fix UBSAN warning in ocfs2_verify_volume()
  nilfs2: fix null-ptr-deref in block_dirty_buffer tracepoint
  nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint
  mm: page_alloc: move mlocked flag clearance into free_pages_prepare()
  mm: count zeromap read and set for swapout and swapin

Documentation/admin-guide/cgroup-v2.rst

@@ -1599,6 +1599,15 @@ The following nested keys are defined.
 	  pglazyfreed (npn)
 		Amount of reclaimed lazyfree pages
 
+	  swpin_zero
+		Number of pages swapped into memory and filled with zero, where I/O
+		was optimized out because the page content was detected to be zero
+		during swapout.
+
+	  swpout_zero
+		Number of zero-filled pages swapped out with I/O skipped due to the
+		content being detected as zero.
+
 	  zswpin
 		Number of pages moved in to memory from zswap.
 

fs/nilfs2/btnode.c

@@ -68,7 +68,6 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr)
 		goto failed;
 	}
 	memset(bh->b_data, 0, i_blocksize(inode));
-	bh->b_bdev = inode->i_sb->s_bdev;
 	bh->b_blocknr = blocknr;
 	set_buffer_mapped(bh);
 	set_buffer_uptodate(bh);
@@ -133,7 +132,6 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
 		goto found;
 	}
 	set_buffer_mapped(bh);
-	bh->b_bdev = inode->i_sb->s_bdev;
 	bh->b_blocknr = pblocknr; /* set block address for read */
 	bh->b_end_io = end_buffer_read_sync;
 	get_bh(bh);

fs/nilfs2/gcinode.c

@@ -83,10 +83,8 @@ int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff,
 		goto out;
 	}
 
-	if (!buffer_mapped(bh)) {
+	if (!buffer_mapped(bh))
-		bh->b_bdev = inode->i_sb->s_bdev;
 		set_buffer_mapped(bh);
-	}
 	bh->b_blocknr = pbn;
 	bh->b_end_io = end_buffer_read_sync;
 	get_bh(bh);

fs/nilfs2/mdt.c

@@ -89,7 +89,6 @@ static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
 	if (buffer_uptodate(bh))
 		goto failed_bh;
 
-	bh->b_bdev = sb->s_bdev;
 	err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
 	if (likely(!err)) {
 		get_bh(bh);

fs/nilfs2/page.c

@@ -39,7 +39,6 @@ static struct buffer_head *__nilfs_get_folio_block(struct folio *folio,
 	first_block = (unsigned long)index << (PAGE_SHIFT - blkbits);
 	bh = get_nth_bh(bh, block - first_block);
 
-	touch_buffer(bh);
 	wait_on_buffer(bh);
 	return bh;
 }
@@ -64,6 +63,7 @@ struct buffer_head *nilfs_grab_buffer(struct inode *inode,
 		folio_put(folio);
 		return NULL;
 	}
+	bh->b_bdev = inode->i_sb->s_bdev;
 	return bh;
 }
 

fs/ocfs2/super.c

@@ -2319,6 +2319,7 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
 			       struct ocfs2_blockcheck_stats *stats)
 {
 	int status = -EAGAIN;
+	u32 blksz_bits;
 
 	if (memcmp(di->i_signature, OCFS2_SUPER_BLOCK_SIGNATURE,
 		   strlen(OCFS2_SUPER_BLOCK_SIGNATURE)) == 0) {
@@ -2333,11 +2334,15 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
 				goto out;
 		}
 		status = -EINVAL;
-		if ((1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits)) != blksz) {
+		/* Acceptable block sizes are 512 bytes, 1K, 2K and 4K. */
+		blksz_bits = le32_to_cpu(di->id2.i_super.s_blocksize_bits);
+		if (blksz_bits < 9 || blksz_bits > 12) {
 			mlog(ML_ERROR, "found superblock with incorrect block "
-			     "size: found %u, should be %u\n",
+			     "size bits: found %u, should be 9, 10, 11, or 12\n",
-			     1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits),
+			     blksz_bits);
-			       blksz);
+		} else if ((1 << le32_to_cpu(blksz_bits)) != blksz) {
+			mlog(ML_ERROR, "found superblock with incorrect block "
+			     "size: found %u, should be %u\n", 1 << blksz_bits, blksz);
 		} else if (le16_to_cpu(di->id2.i_super.s_major_rev_level) !=
 			   OCFS2_MAJOR_REV_LEVEL ||
 			   le16_to_cpu(di->id2.i_super.s_minor_rev_level) !=

include/linux/memcontrol.h

@@ -1760,8 +1760,9 @@ static inline int memcg_kmem_id(struct mem_cgroup *memcg)
 
 struct mem_cgroup *mem_cgroup_from_slab_obj(void *p);
 
-static inline void count_objcg_event(struct obj_cgroup *objcg,
+static inline void count_objcg_events(struct obj_cgroup *objcg,
-				     enum vm_event_item idx)
+				      enum vm_event_item idx,
+				      unsigned long count)
 {
 	struct mem_cgroup *memcg;
 
@@ -1770,7 +1771,7 @@ static inline void count_objcg_event(struct obj_cgroup *objcg,
 
 	rcu_read_lock();
 	memcg = obj_cgroup_memcg(objcg);
-	count_memcg_events(memcg, idx, 1);
+	count_memcg_events(memcg, idx, count);
 	rcu_read_unlock();
 }
 
@@ -1825,8 +1826,9 @@ static inline struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
 	return NULL;
 }
 
-static inline void count_objcg_event(struct obj_cgroup *objcg,
+static inline void count_objcg_events(struct obj_cgroup *objcg,
-				     enum vm_event_item idx)
+				      enum vm_event_item idx,
+				      unsigned long count)
 {
 }
 

include/linux/vm_event_item.h

@@ -134,6 +134,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 #ifdef CONFIG_SWAP
 		SWAP_RA,
 		SWAP_RA_HIT,
+		SWPIN_ZERO,
+		SWPOUT_ZERO,
 #ifdef CONFIG_KSM
 		KSM_SWPIN_COPY,
 #endif

mm/gup.c

@@ -2273,20 +2273,57 @@ struct page *get_dump_page(unsigned long addr)
 #endif /* CONFIG_ELF_CORE */
 
 #ifdef CONFIG_MIGRATION
+
+/*
+ * An array of either pages or folios ("pofs"). Although it may seem tempting to
+ * avoid this complication, by simply interpreting a list of folios as a list of
+ * pages, that approach won't work in the longer term, because eventually the
+ * layouts of struct page and struct folio will become completely different.
+ * Furthermore, this pof approach avoids excessive page_folio() calls.
+ */
+struct pages_or_folios {
+	union {
+		struct page **pages;
+		struct folio **folios;
+		void **entries;
+	};
+	bool has_folios;
+	long nr_entries;
+};
+
+static struct folio *pofs_get_folio(struct pages_or_folios *pofs, long i)
+{
+	if (pofs->has_folios)
+		return pofs->folios[i];
+	return page_folio(pofs->pages[i]);
+}
+
+static void pofs_clear_entry(struct pages_or_folios *pofs, long i)
+{
+	pofs->entries[i] = NULL;
+}
+
+static void pofs_unpin(struct pages_or_folios *pofs)
+{
+	if (pofs->has_folios)
+		unpin_folios(pofs->folios, pofs->nr_entries);
+	else
+		unpin_user_pages(pofs->pages, pofs->nr_entries);
+}
+
 /*
  * Returns the number of collected folios. Return value is always >= 0.
  */
 static unsigned long collect_longterm_unpinnable_folios(
-					struct list_head *movable_folio_list,
+		struct list_head *movable_folio_list,
-					unsigned long nr_folios,
+		struct pages_or_folios *pofs)
-					struct folio **folios)
 {
 	unsigned long i, collected = 0;
 	struct folio *prev_folio = NULL;
 	bool drain_allow = true;
 
-	for (i = 0; i < nr_folios; i++) {
+	for (i = 0; i < pofs->nr_entries; i++) {
-		struct folio *folio = folios[i];
+		struct folio *folio = pofs_get_folio(pofs, i);
 
 		if (folio == prev_folio)
 			continue;
@@ -2327,16 +2364,15 @@ static unsigned long collect_longterm_unpinnable_folios(
  * Returns -EAGAIN if all folios were successfully migrated or -errno for
  * failure (or partial success).
  */
-static int migrate_longterm_unpinnable_folios(
+static int
-					struct list_head *movable_folio_list,
+migrate_longterm_unpinnable_folios(struct list_head *movable_folio_list,
-					unsigned long nr_folios,
+				   struct pages_or_folios *pofs)
-					struct folio **folios)
 {
 	int ret;
 	unsigned long i;
 
-	for (i = 0; i < nr_folios; i++) {
+	for (i = 0; i < pofs->nr_entries; i++) {
-		struct folio *folio = folios[i];
+		struct folio *folio = pofs_get_folio(pofs, i);
 
 		if (folio_is_device_coherent(folio)) {
 			/*
@@ -2344,7 +2380,7 @@ static int migrate_longterm_unpinnable_folios(
 			 * convert the pin on the source folio to a normal
 			 * reference.
 			 */
-			folios[i] = NULL;
+			pofs_clear_entry(pofs, i);
 			folio_get(folio);
 			gup_put_folio(folio, 1, FOLL_PIN);
 
@@ -2363,8 +2399,8 @@ static int migrate_longterm_unpinnable_folios(
 		 * calling folio_isolate_lru() which takes a reference so the
 		 * folio won't be freed if it's migrating.
 		 */
-		unpin_folio(folios[i]);
+		unpin_folio(folio);
-		folios[i] = NULL;
+		pofs_clear_entry(pofs, i);
 	}
 
 	if (!list_empty(movable_folio_list)) {
@@ -2387,12 +2423,26 @@ static int migrate_longterm_unpinnable_folios(
 	return -EAGAIN;
 
 err:
-	unpin_folios(folios, nr_folios);
+	pofs_unpin(pofs);
 	putback_movable_pages(movable_folio_list);
 
 	return ret;
 }
 
+static long
+check_and_migrate_movable_pages_or_folios(struct pages_or_folios *pofs)
+{
+	LIST_HEAD(movable_folio_list);
+	unsigned long collected;
+
+	collected = collect_longterm_unpinnable_folios(&movable_folio_list,
+						       pofs);
+	if (!collected)
+		return 0;
+
+	return migrate_longterm_unpinnable_folios(&movable_folio_list, pofs);
+}
+
 /*
  * Check whether all folios are *allowed* to be pinned indefinitely (long term).
  * Rather confusingly, all folios in the range are required to be pinned via
@@ -2417,16 +2467,13 @@ err:
 static long check_and_migrate_movable_folios(unsigned long nr_folios,
 					     struct folio **folios)
 {
-	unsigned long collected;
+	struct pages_or_folios pofs = {
-	LIST_HEAD(movable_folio_list);
+		.folios = folios,
+		.has_folios = true,
+		.nr_entries = nr_folios,
+	};
 
-	collected = collect_longterm_unpinnable_folios(&movable_folio_list,
+	return check_and_migrate_movable_pages_or_folios(&pofs);
-						       nr_folios, folios);
-	if (!collected)
-		return 0;
-
-	return migrate_longterm_unpinnable_folios(&movable_folio_list,
-						  nr_folios, folios);
 }
 
 /*
@@ -2436,22 +2483,13 @@ static long check_and_migrate_movable_folios(unsigned long nr_folios,
 static long check_and_migrate_movable_pages(unsigned long nr_pages,
 					    struct page **pages)
 {
-	struct folio **folios;
+	struct pages_or_folios pofs = {
-	long i, ret;
+		.pages = pages,
+		.has_folios = false,
+		.nr_entries = nr_pages,
+	};
 
-	folios = kmalloc_array(nr_pages, sizeof(*folios), GFP_KERNEL);
+	return check_and_migrate_movable_pages_or_folios(&pofs);
-	if (!folios) {
-		unpin_user_pages(pages, nr_pages);
-		return -ENOMEM;
-	}
-
-	for (i = 0; i < nr_pages; i++)
-		folios[i] = page_folio(pages[i]);
-
-	ret = check_and_migrate_movable_folios(nr_pages, folios);
-
-	kfree(folios);
-	return ret;
 }
 #else
 static long check_and_migrate_movable_pages(unsigned long nr_pages,

mm/huge_memory.c

@@ -3790,7 +3790,9 @@ next:
 		 * in the case it was underused, then consider it used and
 		 * don't add it back to split_queue.
 		 */
-		if (!did_split && !folio_test_partially_mapped(folio)) {
+		if (did_split) {
+			; /* folio already removed from list */
+		} else if (!folio_test_partially_mapped(folio)) {
 			list_del_init(&folio->_deferred_list);
 			removed++;
 		} else {

mm/memcontrol.c

@@ -431,6 +431,10 @@ static const unsigned int memcg_vm_event_stat[] = {
 	PGDEACTIVATE,
 	PGLAZYFREE,
 	PGLAZYFREED,
+#ifdef CONFIG_SWAP
+	SWPIN_ZERO,
+	SWPOUT_ZERO,
+#endif
 #ifdef CONFIG_ZSWAP
 	ZSWPIN,
 	ZSWPOUT,

mm/nommu.c

@@ -573,7 +573,7 @@ static int delete_vma_from_mm(struct vm_area_struct *vma)
 	VMA_ITERATOR(vmi, vma->vm_mm, vma->vm_start);
 
 	vma_iter_config(&vmi, vma->vm_start, vma->vm_end);
-	if (vma_iter_prealloc(&vmi, vma)) {
+	if (vma_iter_prealloc(&vmi, NULL)) {
 		pr_warn("Allocation of vma tree for process %d failed\n",
 		       current->pid);
 		return -ENOMEM;

mm/page_alloc.c

@@ -1048,6 +1048,7 @@ __always_inline bool free_pages_prepare(struct page *page,
 	bool skip_kasan_poison = should_skip_kasan_poison(page);
 	bool init = want_init_on_free();
 	bool compound = PageCompound(page);
+	struct folio *folio = page_folio(page);
 
 	VM_BUG_ON_PAGE(PageTail(page), page);
 
@@ -1057,6 +1058,20 @@ __always_inline bool free_pages_prepare(struct page *page,
 	if (memcg_kmem_online() && PageMemcgKmem(page))
 		__memcg_kmem_uncharge_page(page, order);
 
+	/*
+	 * In rare cases, when truncation or holepunching raced with
+	 * munlock after VM_LOCKED was cleared, Mlocked may still be
+	 * found set here.  This does not indicate a problem, unless
+	 * "unevictable_pgs_cleared" appears worryingly large.
+	 */
+	if (unlikely(folio_test_mlocked(folio))) {
+		long nr_pages = folio_nr_pages(folio);
+
+		__folio_clear_mlocked(folio);
+		zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
+		count_vm_events(UNEVICTABLE_PGCLEARED, nr_pages);
+	}
+
 	if (unlikely(PageHWPoison(page)) && !order) {
 		/* Do not let hwpoison pages hit pcplists/buddy */
 		reset_page_owner(page, order);

mm/page_io.c

@@ -204,7 +204,9 @@ static bool is_folio_zero_filled(struct folio *folio)
 
 static void swap_zeromap_folio_set(struct folio *folio)
 {
+	struct obj_cgroup *objcg = get_obj_cgroup_from_folio(folio);
 	struct swap_info_struct *sis = swp_swap_info(folio->swap);
+	int nr_pages = folio_nr_pages(folio);
 	swp_entry_t entry;
 	unsigned int i;
 
@@ -212,6 +214,12 @@ static void swap_zeromap_folio_set(struct folio *folio)
 		entry = page_swap_entry(folio_page(folio, i));
 		set_bit(swp_offset(entry), sis->zeromap);
 	}
+
+	count_vm_events(SWPOUT_ZERO, nr_pages);
+	if (objcg) {
+		count_objcg_events(objcg, SWPOUT_ZERO, nr_pages);
+		obj_cgroup_put(objcg);
+	}
 }
 
 static void swap_zeromap_folio_clear(struct folio *folio)
@@ -503,6 +511,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
 static bool swap_read_folio_zeromap(struct folio *folio)
 {
 	int nr_pages = folio_nr_pages(folio);
+	struct obj_cgroup *objcg;
 	bool is_zeromap;
 
 	/*
@@ -517,6 +526,13 @@ static bool swap_read_folio_zeromap(struct folio *folio)
 	if (!is_zeromap)
 		return false;
 
+	objcg = get_obj_cgroup_from_folio(folio);
+	count_vm_events(SWPIN_ZERO, nr_pages);
+	if (objcg) {
+		count_objcg_events(objcg, SWPIN_ZERO, nr_pages);
+		obj_cgroup_put(objcg);
+	}
+
 	folio_zero_range(folio, 0, folio_size(folio));
 	folio_mark_uptodate(folio);
 	return true;

mm/swap.c

@@ -78,20 +78,6 @@ static void __page_cache_release(struct folio *folio, struct lruvec **lruvecp,
 		lruvec_del_folio(*lruvecp, folio);
 		__folio_clear_lru_flags(folio);
 	}
-
-	/*
-	 * In rare cases, when truncation or holepunching raced with
-	 * munlock after VM_LOCKED was cleared, Mlocked may still be
-	 * found set here.  This does not indicate a problem, unless
-	 * "unevictable_pgs_cleared" appears worryingly large.
-	 */
-	if (unlikely(folio_test_mlocked(folio))) {
-		long nr_pages = folio_nr_pages(folio);
-
-		__folio_clear_mlocked(folio);
-		zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
-		count_vm_events(UNEVICTABLE_PGCLEARED, nr_pages);
-	}
 }
 
 /*

mm/swapfile.c

@@ -929,7 +929,7 @@ static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
 		si->highest_bit = 0;
 		del_from_avail_list(si);
 
-		if (vm_swap_full())
+		if (si->cluster_info && vm_swap_full())
 			schedule_work(&si->reclaim_work);
 	}
 }

mm/vmstat.c

@@ -1415,6 +1415,8 @@ const char * const vmstat_text[] = {
 #ifdef CONFIG_SWAP
 	"swap_ra",
 	"swap_ra_hit",
+	"swpin_zero",
+	"swpout_zero",
 #ifdef CONFIG_KSM
 	"ksm_swpin_copy",
 #endif

mm/zswap.c

@@ -1053,7 +1053,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
 
 	count_vm_event(ZSWPWB);
 	if (entry->objcg)
-		count_objcg_event(entry->objcg, ZSWPWB);
+		count_objcg_events(entry->objcg, ZSWPWB, 1);
 
 	zswap_entry_free(entry);
 
@@ -1483,7 +1483,7 @@ bool zswap_store(struct folio *folio)
 
 	if (objcg) {
 		obj_cgroup_charge_zswap(objcg, entry->length);
-		count_objcg_event(objcg, ZSWPOUT);
+		count_objcg_events(objcg, ZSWPOUT, 1);
 	}
 
 	/*
@@ -1577,7 +1577,7 @@ bool zswap_load(struct folio *folio)
 
 	count_vm_event(ZSWPIN);
 	if (entry->objcg)
-		count_objcg_event(entry->objcg, ZSWPIN);
+		count_objcg_events(entry->objcg, ZSWPIN, 1);
 
 	if (swapcache) {
 		zswap_entry_free(entry);

tools/testing/selftests/mm/hugetlb_dio.c

@@ -44,6 +44,13 @@ void run_dio_using_hugetlb(unsigned int start_off, unsigned int end_off)
 	if (fd < 0)
 		ksft_exit_fail_perror("Error opening file\n");
 
+	/* Get the free huge pages before allocation */
+	free_hpage_b = get_free_hugepages();
+	if (free_hpage_b == 0) {
+		close(fd);
+		ksft_exit_skip("No free hugepage, exiting!\n");
+	}
+
 	/* Allocate a hugetlb page */
 	orig_buffer = mmap(NULL, h_pagesize, mmap_prot, mmap_flags, -1, 0);
 	if (orig_buffer == MAP_FAILED) {