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

Author: torvalds

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)) {
-		bh->b_bdev = inode->i_sb->s_bdev;
+	if (!buffer_mapped(bh))
 		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",
-			     1 << le32_to_cpu(di->id2.i_super.s_blocksize_bits),
-			       blksz);
+			     "size bits: found %u, should be 9, 10, 11, or 12\n",
+			     blksz_bits);
+		} 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,
-				     enum vm_event_item idx)
+static inline void count_objcg_events(struct obj_cgroup *objcg,
+				      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,
-				     enum vm_event_item idx)
+static inline void count_objcg_events(struct obj_cgroup *objcg,
+				      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,
-					unsigned long nr_folios,
-					struct folio **folios)
+		struct list_head *movable_folio_list,
+		struct pages_or_folios *pofs)
 {
 	unsigned long i, collected = 0;
 	struct folio *prev_folio = NULL;
 	bool drain_allow = true;
 
-	for (i = 0; i < nr_folios; i++) {
-		struct folio *folio = folios[i];
+	for (i = 0; i < pofs->nr_entries; i++) {
+		struct folio *folio = pofs_get_folio(pofs, i);
 
 		if (folio == prev_folio)
 			continue;
@@ -2327,24 +2364,23 @@ 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(
-					struct list_head *movable_folio_list,
-					unsigned long nr_folios,
-					struct folio **folios)
+static int
+migrate_longterm_unpinnable_folios(struct list_head *movable_folio_list,
+				   struct pages_or_folios *pofs)
 {
 	int ret;
 	unsigned long i;
 
-	for (i = 0; i < nr_folios; i++) {
-		struct folio *folio = folios[i];
+	for (i = 0; i < pofs->nr_entries; i++) {
+		struct folio *folio = pofs_get_folio(pofs, i);
 
 		if (folio_is_device_coherent(folio)) {
 			/*
 			 * Migration will fail if the folio is pinned, so
 			 * 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]);
-		folios[i] = NULL;
+		unpin_folio(folio);
+		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 @@ static int migrate_longterm_unpinnable_folios(
 static long check_and_migrate_movable_folios(unsigned long nr_folios,
 					     struct folio **folios)
 {
-	unsigned long collected;
-	LIST_HEAD(movable_folio_list);
+	struct pages_or_folios pofs = {
+		.folios = folios,
+		.has_folios = true,
+		.nr_entries = nr_folios,
+	};
 
-	collected = collect_longterm_unpinnable_folios(&movable_folio_list,
-						       nr_folios, folios);
-	if (!collected)
-		return 0;
-
-	return migrate_longterm_unpinnable_folios(&movable_folio_list,
-						  nr_folios, folios);
+	return check_and_migrate_movable_pages_or_folios(&pofs);
 }
 
 /*
@@ -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;
-	long i, ret;
+	struct pages_or_folios pofs = {
+		.pages = pages,
+		.has_folios = false,
+		.nr_entries = nr_pages,
+	};
 
-	folios = kmalloc_array(nr_pages, sizeof(*folios), GFP_KERNEL);
-	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;
+	return check_and_migrate_movable_pages_or_folios(&pofs);
 }
 #else
 static long check_and_migrate_movable_pages(unsigned long nr_pages,

mm/huge_memory.c

@@ -3790,7 +3790,9 @@ static unsigned long deferred_split_scan(struct shrinker *shrink,
 		 * 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 {