Merge tag 'mm-hotfixes-stable-2026-09-13-21-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "14 hotfixes.  10 are cc:stable.  11 are for MM.

  All are singletons - please see the changelogs for details"

* tag 'mm-hotfixes-stable-2026-09-13-21-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/folio: EXPORT_SYMBOL_FOR_KVM(lru_cache_drain_for_folio)
  mm/shrinker: fix bogus set_shrinker_bit() with cgroup.memory=nokmem
  mm/vma: correctly unaccount on mmap_prepare() failure
  mm/mlock: use the IRQ-safe accessor for NR_MLOCK in __munlock_folio()
  remove old lib/alloc_tag.c
  fs/dax: check zero or empty entry before converting xarray entry
  fs: fix missed removal of super_fs_objects_eligible()
  mm: filemap: retain mapped dropbehind folios
  mailmap: update entry for Christopher Obbard
  memcg: avoid charging the root memcg from obj_cgroup_charge_pages()
  mm, swap: fix SWAP_USAGE_OFFLIST_BIT collision with real usage count
  mailmap: map Coiby Xu's address
  mm/mremap: account mm->locked_vm correctly for MREMAP_DONTUNMAP
  mm/huge_memory: bypass THP tuneables for huge pfnmap mappings

.mailmap

@@ -211,7 +211,8 @@ Christophe Leroy <chleroy@kernel.org> <christophe.leroy@c-s.fr>
 Christophe Leroy <chleroy@kernel.org> <christophe.leroy@csgroup.eu>
 Christophe Leroy <chleroy@kernel.org> <christophe.leroy2@cs-soprasteria.com>
 Christophe Ricard <christophe.ricard@gmail.com>
-Christopher Obbard <christopher.obbard@linaro.org> <chris.obbard@collabora.com>
+Christopher Obbard <chris.obbard@oss.qualcomm.com> <chris.obbard@collabora.com>
+Christopher Obbard <chris.obbard@oss.qualcomm.com> <christopher.obbard@linaro.org>
 Christoph Hellwig <hch@lst.de>
 Christoph Manszewski <c.manszewski@gmail.com> <christoph.manszewski@intel.com>
 Christoph Paasch <cpaasch@openai.com> <christoph.paasch@gmail.com>
@@ -222,6 +223,7 @@ Chuck Lever <cel@kernel.org> <chuck.lever@oracle.com>
 Chuck Lever <cel@kernel.org> <cel@netapp.com>
 Chuck Lever <cel@kernel.org> <cel@citi.umich.edu>
 Claudiu Beznea <claudiu.beznea@tuxon.dev> <claudiu.beznea@microchip.com>
+Coiby Xu <coiby.xu@gmail.com> <coxu@redhat.com>
 Colin Ian King <colin.i.king@gmail.com> <colin.king@canonical.com>
 Corey Minyard <minyard@acm.org>
 Damian Hobson-Garcia <dhobsong@igel.co.jp>

fs/dax.c

@@ -480,11 +480,12 @@ static void dax_associate_entry(void *entry, struct address_space *mapping,
 				unsigned long address, bool shared)
 {
 	unsigned long size = dax_entry_size(entry), index;
-	struct folio *folio = dax_to_folio(entry);
+	struct folio *folio;
 
 	if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry))
 		return;
 
+	folio = dax_to_folio(entry);
 	index = linear_page_index(vma, address & ~(size - 1));
 	if (shared && (folio->mapping || dax_folio_is_shared(folio))) {
 		if (folio->mapping)
@@ -505,21 +506,23 @@ static void dax_associate_entry(void *entry, struct address_space *mapping,
 static void dax_disassociate_entry(void *entry, struct address_space *mapping,
 				bool trunc)
 {
-	struct folio *folio = dax_to_folio(entry);
+	struct folio *folio;
 
 	if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry))
 		return;
 
+	folio = dax_to_folio(entry);
 	dax_folio_put(folio);
 }
 
 static struct page *dax_busy_page(void *entry)
 {
-	struct folio *folio = dax_to_folio(entry);
+	struct folio *folio;
 
 	if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry))
 		return NULL;
 
+	folio = dax_to_folio(entry);
 	if (folio_ref_count(folio) - folio_mapcount(folio))
 		return &folio->page;
 	else

fs/super.c

@@ -171,19 +171,6 @@ static void super_wake(struct super_block *sb, unsigned int flag)
 	wake_up_var(&sb->s_flags);
 }
 
-/*
- * The s_op->nr_cached_objects hooks (used for example by btrfs and xfs)
- * operate on filesystem-global state and ignore sc->memcg. Driving them
- * from per-memcg shrink_slab_memcg() invocations only burns CPU walking
- * per-cpu counters and queueing duplicate work: the actual reclaim happens on
- * the global path (kswapd or root direct reclaim) regardless. Restrict them
- * to that path.
- */
-static inline bool super_fs_objects_eligible(struct shrink_control *sc)
-{
-	return !sc->memcg || mem_cgroup_is_root(sc->memcg);
-}
-
 /*
  * One thing we have to be careful of with a per-sb shrinker is that we don't
  * drop the last active reference to the superblock from within the shrinker.
@@ -213,7 +200,7 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
 	if (!super_trylock_shared(sb))
 		return SHRINK_STOP;
 
-	if (sb->s_op->nr_cached_objects && super_fs_objects_eligible(sc))
+	if (sb->s_op->nr_cached_objects)
 		fs_objects = sb->s_op->nr_cached_objects(sb, sc);
 
 	inodes = list_lru_shrink_count(&sb->s_inode_lru, sc);
@@ -274,8 +261,7 @@ static unsigned long super_cache_count(struct shrinker *shrink,
 		return 0;
 	smp_rmb();
 
-	if (sb->s_op && sb->s_op->nr_cached_objects &&
-	    super_fs_objects_eligible(sc))
+	if (sb->s_op && sb->s_op->nr_cached_objects)
 		total_objects = sb->s_op->nr_cached_objects(sb, sc);
 
 	total_objects += list_lru_shrink_count(&sb->s_dentry_lru, sc);

mm/filemap.c

@@ -1616,7 +1616,7 @@ static void filemap_end_dropbehind(struct folio *folio)
 		return;
 	if (!folio_test_clear_dropbehind(folio))
 		return;
-	if (mapping)
+	if (mapping && !folio_mapped(folio))
 		folio_unmap_invalidate(mapping, folio, 0);
 }
 

mm/folio.c

@@ -33,6 +33,7 @@
 #include <linux/page_idle.h>
 #include <linux/local_lock.h>
 #include <linux/buffer_head.h>
+#include <linux/kvm_types.h>
 
 #include "internal.h"
 #include "page_alloc.h"
@@ -926,6 +927,7 @@ void lru_cache_drain_for_folio(const struct folio *folio,
 			*drained = LRU_CACHE_DRAINED_ALL;
 	}
 }
+EXPORT_SYMBOL_FOR_KVM(lru_cache_drain_for_folio);
 
 atomic_t lru_disable_count = ATOMIC_INIT(0);
 

mm/huge_memory.c

@@ -92,7 +92,7 @@ unsigned long huge_anon_orders_madvise __read_mostly;
 unsigned long huge_anon_orders_inherit __read_mostly;
 static bool anon_orders_configured __initdata;
 
-static inline bool file_thp_enabled(struct vm_area_struct *vma)
+static inline bool file_thp_enabled(const struct vm_area_struct *vma)
 {
 	struct inode *inode;
 
@@ -118,6 +118,67 @@ static bool vma_is_special_huge(const struct vm_area_struct *vma)
 	return vma_test_any(vma, VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT);
 }
 
+static bool vma_file_bypass_thp_tuneables(const struct vm_area_struct *vma,
+		enum tva_type type)
+{
+	const bool has_huge_fault = vma->vm_ops->huge_fault;
+
+	/* MADV_COLLAPSE ignores tuneables. */
+	if (type == TVA_FORCED_COLLAPSE)
+		return true;
+	/* Huge PFN mappings are uncompactable so the policy doesn't apply. */
+	if (vma_test(vma, VMA_PFNMAP_BIT) && has_huge_fault)
+		return true;
+	return false;
+}
+
+static bool vma_file_allow_thp_tuneables(vm_flags_t vm_flags)
+{
+	/* THP=always? */
+	if (hugepage_global_always())
+		return true;
+	/* THP=madvise and marked MADV_HUGEPAGE? */
+	if (hugepage_global_enabled() && (vm_flags & VM_HUGEPAGE))
+		return true;
+	return false;
+}
+
+static bool vma_file_check_thp_tuneables(const struct vm_area_struct *vma,
+		vm_flags_t vm_flags, enum tva_type type)
+{
+	return vma_file_bypass_thp_tuneables(vma, type) ||
+		vma_file_allow_thp_tuneables(vm_flags);
+}
+
+static bool vma_can_map_huge_file(const struct vm_area_struct *vma,
+		vm_flags_t vm_flags, enum tva_type type)
+{
+	const bool has_huge_fault = vma->vm_ops->huge_fault;
+
+	/*
+	 * Enforce THP collapse requirements as necessary. Anonymous vmas
+	 * were already handled in thp_vma_allowable_orders().
+	 */
+	if (!vma_file_check_thp_tuneables(vma, vm_flags, type))
+		return false;
+
+	switch (type) {
+	case TVA_PAGEFAULT:
+		/*
+		 * Trust that ->huge_fault() handlers know what they are doing
+		 * in fault path.
+		 */
+		return has_huge_fault;
+	case TVA_SMAPS:
+		if (has_huge_fault)
+			return true;
+		fallthrough;
+	default:
+		/* Only regular file is valid in collapse path. */
+		return file_thp_enabled(vma);
+	}
+}
+
 unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
 					 vm_flags_t vm_flags,
 					 enum tva_type type,
@@ -190,27 +251,8 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
 						   vma, vma_start_pgoff(vma), 0,
 						   forced_collapse);
 
-	if (!vma_is_anonymous(vma)) {
-		/*
-		 * Enforce THP collapse requirements as necessary. Anonymous vmas
-		 * were already handled in thp_vma_allowable_orders().
-		 */
-		if (!forced_collapse &&
-		    (!hugepage_global_enabled() || (!(vm_flags & VM_HUGEPAGE) &&
-						    !hugepage_global_always())))
-			return 0;
-
-		/*
-		 * Trust that ->huge_fault() handlers know what they are doing
-		 * in fault path.
-		 */
-		if (((in_pf || smaps)) && vma->vm_ops->huge_fault)
-			return orders;
-		/* Only regular file is valid in collapse path */
-		if (((!in_pf || smaps)) && file_thp_enabled(vma))
-			return orders;
-		return 0;
-	}
+	if (!vma_is_anonymous(vma))
+		return vma_can_map_huge_file(vma, vm_flags, type) ? orders : 0;
 
 	if (vma_is_temporary_stack(vma))
 		return 0;

mm/memcontrol.c

@@ -3158,7 +3158,7 @@ static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp,
 
 	memcg = get_mem_cgroup_from_objcg(objcg);
 
-	ret = try_charge_memcg(memcg, gfp, nr_pages);
+	ret = try_charge(memcg, gfp, nr_pages);
 	if (ret)
 		goto out;
 

mm/mlock.c

@@ -141,7 +141,7 @@ static struct lruvec *__munlock_folio(struct folio *folio, struct lruvec *lruvec
 
 munlock:
 	if (folio_test_clear_mlocked(folio)) {
-		__zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
+		zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
 		if (isolated || !folio_test_unevictable(folio))
 			__count_vm_events(UNEVICTABLE_PGMUNLOCKED, nr_pages);
 		else

mm/mremap.c

@@ -1355,12 +1355,11 @@ static void dontunmap_complete(struct vma_remap_struct *vrm,
 		if (vma_is_anonymous(vma) && !vma->vm_file)
 			vma_set_pgoff(vma, pgoff_unfaulted);
 	}
-
-	/* Because we won't unmap we don't need to touch locked_vm. */
 }
 
 static unsigned long move_vma(struct vma_remap_struct *vrm)
 {
+	const bool is_dontunmap = vrm->flags & MREMAP_DONTUNMAP;
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *new_vma;
 	unsigned long hiwater_vm;
@@ -1401,10 +1400,10 @@ static unsigned long move_vma(struct vma_remap_struct *vrm)
 	 */
 	hiwater_vm = mm->hiwater_vm;
 
-	vrm_stat_account(vrm, vrm->new_len);
-	if (unlikely(!err && (vrm->flags & MREMAP_DONTUNMAP)))
+	if (unlikely(is_dontunmap && !err))
 		dontunmap_complete(vrm, new_vma);
-	else
+	vrm_stat_account(vrm, vrm->new_len);
+	if (!is_dontunmap || err)
 		unmap_source_vma(vrm);
 
 	mm->hiwater_vm = hiwater_vm;

mm/shrinker.c

@@ -227,6 +227,8 @@ static int shrinker_memcg_alloc(struct shrinker *shrinker)
 {
 	int id;
 
+	shrinker->id = -1;
+
 	if (mem_cgroup_disabled())
 		return -ENOSYS;
 	if (mem_cgroup_kmem_disabled() && !(shrinker->flags & SHRINKER_NONSLAB))

mm/swapfile.c

@@ -156,7 +156,7 @@ static struct swap_info_struct *swap_entry_to_info(swp_entry_t entry)
  * This bit will be set if the device is not on the plist and not
  * usable, will be cleared if the device is on the plist.
  */
-#define SWAP_USAGE_OFFLIST_BIT (1UL << (BITS_PER_TYPE(atomic_t) - 2))
+#define SWAP_USAGE_OFFLIST_BIT (1UL << (BITS_PER_TYPE(atomic_long_t) - 2))
 #define SWAP_USAGE_COUNTER_MASK (~SWAP_USAGE_OFFLIST_BIT)
 static long swap_usage_in_pages(struct swap_info_struct *si)
 {

mm/vma.c

@@ -2859,10 +2859,12 @@ static unsigned long __mmap_region(struct file *file, unsigned long addr,
 	map.check_ksm_early = can_set_ksm_flags_early(&map);
 
 	error = __mmap_setup(&map, &desc, uf);
-	if (!error && have_mmap_prepare)
-		error = call_mmap_prepare(&map, &desc);
 	if (error)
 		goto abort_munmap;
+	if (have_mmap_prepare)
+		error = call_mmap_prepare(&map, &desc);
+	if (error)
+		goto unacct_error;
 
 	if (map.check_ksm_early)
 		update_ksm_flags(&map);