Memory folios

Add memory folios, a new type to represent either order-0 pages or
 the head page of a compound page.  This should be enough infrastructure
 to support filesystems converting from pages to folios.
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Merge tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache

Pull memory folios from Matthew Wilcox:
 "Add memory folios, a new type to represent either order-0 pages or the
  head page of a compound page. This should be enough infrastructure to
  support filesystems converting from pages to folios.

  The point of all this churn is to allow filesystems and the page cache
  to manage memory in larger chunks than PAGE_SIZE. The original plan
  was to use compound pages like THP does, but I ran into problems with
  some functions expecting only a head page while others expect the
  precise page containing a particular byte.

  The folio type allows a function to declare that it's expecting only a
  head page. Almost incidentally, this allows us to remove various calls
  to VM_BUG_ON(PageTail(page)) and compound_head().

  This converts just parts of the core MM and the page cache. For 5.17,
  we intend to convert various filesystems (XFS and AFS are ready; other
  filesystems may make it) and also convert more of the MM and page
  cache to folios. For 5.18, multi-page folios should be ready.

  The multi-page folios offer some improvement to some workloads. The
  80% win is real, but appears to be an artificial benchmark (postgres
  startup, which isn't a serious workload). Real workloads (eg building
  the kernel, running postgres in a steady state, etc) seem to benefit
  between 0-10%. I haven't heard of any performance losses as a result
  of this series. Nobody has done any serious performance tuning; I
  imagine that tweaking the readahead algorithm could provide some more
  interesting wins. There are also other places where we could choose to
  create large folios and currently do not, such as writes that are
  larger than PAGE_SIZE.

  I'd like to thank all my reviewers who've offered review/ack tags:
  Christoph Hellwig, David Howells, Jan Kara, Jeff Layton, Johannes
  Weiner, Kirill A. Shutemov, Michal Hocko, Mike Rapoport, Vlastimil
  Babka, William Kucharski, Yu Zhao and Zi Yan.

  I'd also like to thank those who gave feedback I incorporated but
  haven't offered up review tags for this part of the series: Nick
  Piggin, Mel Gorman, Ming Lei, Darrick Wong, Ted Ts'o, John Hubbard,
  Hugh Dickins, and probably a few others who I forget"

* tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache: (90 commits)
  mm/writeback: Add folio_write_one
  mm/filemap: Add FGP_STABLE
  mm/filemap: Add filemap_get_folio
  mm/filemap: Convert mapping_get_entry to return a folio
  mm/filemap: Add filemap_add_folio()
  mm/filemap: Add filemap_alloc_folio
  mm/page_alloc: Add folio allocation functions
  mm/lru: Add folio_add_lru()
  mm/lru: Convert __pagevec_lru_add_fn to take a folio
  mm: Add folio_evictable()
  mm/workingset: Convert workingset_refault() to take a folio
  mm/filemap: Add readahead_folio()
  mm/filemap: Add folio_mkwrite_check_truncate()
  mm/filemap: Add i_blocks_per_folio()
  mm/writeback: Add folio_redirty_for_writepage()
  mm/writeback: Add folio_account_redirty()
  mm/writeback: Add folio_clear_dirty_for_io()
  mm/writeback: Add folio_cancel_dirty()
  mm/writeback: Add folio_account_cleaned()
  mm/writeback: Add filemap_dirty_folio()
  ...

Documentation/core-api/cachetlb.rst

@@ -326,6 +326,12 @@ maps this page at its virtual address.
 			dirty.  Again, see sparc64 for examples of how
 			to deal with this.
 
+  ``void flush_dcache_folio(struct folio *folio)``
+	This function is called under the same circumstances as
+	flush_dcache_page().  It allows the architecture to
+	optimise for flushing the entire folio of pages instead
+	of flushing one page at a time.
+
   ``void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
   unsigned long user_vaddr, void *dst, void *src, int len)``
   ``void copy_from_user_page(struct vm_area_struct *vma, struct page *page,

Documentation/core-api/mm-api.rst

@@ -95,6 +95,11 @@ More Memory Management Functions
 .. kernel-doc:: mm/mempolicy.c
 .. kernel-doc:: include/linux/mm_types.h
    :internal:
+.. kernel-doc:: include/linux/mm_inline.h
+.. kernel-doc:: include/linux/page-flags.h
 .. kernel-doc:: include/linux/mm.h
    :internal:
+.. kernel-doc:: include/linux/page_ref.h
 .. kernel-doc:: include/linux/mmzone.h
+.. kernel-doc:: mm/util.c
+   :functions: folio_mapping

Documentation/filesystems/netfs_library.rst

@@ -524,3 +524,5 @@ Note that these methods are passed a pointer to the cache resource structure,
 not the read request structure as they could be used in other situations where
 there isn't a read request structure as well, such as writing dirty data to the
 cache.
+
+.. kernel-doc:: include/linux/netfs.h

arch/arc/include/asm/cacheflush.h

@@ -36,6 +36,7 @@ void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr);
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 
 void flush_dcache_page(struct page *page);
+void flush_dcache_folio(struct folio *folio);
 
 void dma_cache_wback_inv(phys_addr_t start, unsigned long sz);
 void dma_cache_inv(phys_addr_t start, unsigned long sz);

arch/arm/include/asm/cacheflush.h

@@ -290,6 +290,7 @@ extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr
  */
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *);
+void flush_dcache_folio(struct folio *folio);
 
 #define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 static inline void flush_kernel_vmap_range(void *addr, int size)

arch/m68k/include/asm/cacheflush_mm.h

@@ -250,6 +250,7 @@ static inline void __flush_page_to_ram(void *vaddr)
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 #define flush_dcache_page(page)		__flush_page_to_ram(page_address(page))
+void flush_dcache_folio(struct folio *folio);
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)
 #define flush_icache_page(vma, page)	__flush_page_to_ram(page_address(page))

arch/mips/include/asm/cacheflush.h

@@ -61,6 +61,8 @@ static inline void flush_dcache_page(struct page *page)
 		SetPageDcacheDirty(page);
 }
 
+void flush_dcache_folio(struct folio *folio);
+
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)
 

arch/nds32/include/asm/cacheflush.h

@@ -27,6 +27,7 @@ void flush_cache_vunmap(unsigned long start, unsigned long end);
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 void flush_dcache_page(struct page *page);
+void flush_dcache_folio(struct folio *folio);
 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
 		       unsigned long vaddr, void *dst, void *src, int len);
 void copy_from_user_page(struct vm_area_struct *vma, struct page *page,

arch/nios2/include/asm/cacheflush.h

@@ -28,7 +28,8 @@ extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
 extern void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
 	unsigned long pfn);
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
-extern void flush_dcache_page(struct page *page);
+void flush_dcache_page(struct page *page);
+void flush_dcache_folio(struct folio *folio);
 
 extern void flush_icache_range(unsigned long start, unsigned long end);
 extern void flush_icache_page(struct vm_area_struct *vma, struct page *page);

arch/parisc/include/asm/cacheflush.h

@@ -49,7 +49,8 @@ void invalidate_kernel_vmap_range(void *vaddr, int size);
 #define flush_cache_vunmap(start, end)		flush_cache_all()
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
-extern void flush_dcache_page(struct page *page);
+void flush_dcache_page(struct page *page);
+void flush_dcache_folio(struct folio *folio);
 
 #define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)
 #define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)

arch/sh/include/asm/cacheflush.h

@@ -42,7 +42,8 @@ extern void flush_cache_page(struct vm_area_struct *vma,
 extern void flush_cache_range(struct vm_area_struct *vma,
 				 unsigned long start, unsigned long end);
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
-extern void flush_dcache_page(struct page *page);
+void flush_dcache_page(struct page *page);
+void flush_dcache_folio(struct folio *folio);
 extern void flush_icache_range(unsigned long start, unsigned long end);
 #define flush_icache_user_range flush_icache_range
 extern void flush_icache_page(struct vm_area_struct *vma,

arch/xtensa/include/asm/cacheflush.h

@@ -120,7 +120,8 @@ void flush_cache_page(struct vm_area_struct*,
 #define flush_cache_vunmap(start,end)	flush_cache_all()
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
-extern void flush_dcache_page(struct page*);
+void flush_dcache_page(struct page *);
+void flush_dcache_folio(struct folio *);
 
 void local_flush_cache_range(struct vm_area_struct *vma,
 		unsigned long start, unsigned long end);
@@ -137,7 +138,9 @@ void local_flush_cache_page(struct vm_area_struct *vma,
 #define flush_cache_vunmap(start,end)			do { } while (0)
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
 #define flush_dcache_page(page)				do { } while (0)
+static inline void flush_dcache_folio(struct folio *folio) { }
 
 #define flush_icache_range local_flush_icache_range
 #define flush_cache_page(vma, addr, pfn)		do { } while (0)

fs/afs/write.c

@@ -861,7 +861,8 @@ int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  */
 vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
 {
-	struct page *page = thp_head(vmf->page);
+	struct folio *folio = page_folio(vmf->page);
+	struct page *page = &folio->page;
 	struct file *file = vmf->vma->vm_file;
 	struct inode *inode = file_inode(file);
 	struct afs_vnode *vnode = AFS_FS_I(inode);
@@ -884,7 +885,7 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
 		goto out;
 #endif
 
-	if (wait_on_page_writeback_killable(page))
+	if (folio_wait_writeback_killable(folio))
 		goto out;
 
 	if (lock_page_killable(page) < 0)
@@ -894,8 +895,8 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
 	 * details the portion of the page we need to write back and we might
 	 * need to redirty the page if there's a problem.
 	 */
-	if (wait_on_page_writeback_killable(page) < 0) {
+	if (folio_wait_writeback_killable(folio) < 0) {
-		unlock_page(page);
+		folio_unlock(folio);
 		goto out;
 	}
 

fs/cachefiles/rdwr.c

@@ -25,20 +25,20 @@ static int cachefiles_read_waiter(wait_queue_entry_t *wait, unsigned mode,
 	struct cachefiles_object *object;
 	struct fscache_retrieval *op = monitor->op;
 	struct wait_page_key *key = _key;
-	struct page *page = wait->private;
+	struct folio *folio = wait->private;
 
 	ASSERT(key);
 
 	_enter("{%lu},%u,%d,{%p,%u}",
 	       monitor->netfs_page->index, mode, sync,
-	       key->page, key->bit_nr);
+	       key->folio, key->bit_nr);
 
-	if (key->page != page || key->bit_nr != PG_locked)
+	if (key->folio != folio || key->bit_nr != PG_locked)
 		return 0;
 
-	_debug("--- monitor %p %lx ---", page, page->flags);
+	_debug("--- monitor %p %lx ---", folio, folio->flags);
 
-	if (!PageUptodate(page) && !PageError(page)) {
+	if (!folio_test_uptodate(folio) && !folio_test_error(folio)) {
 		/* unlocked, not uptodate and not erronous? */
 		_debug("page probably truncated");
 	}
@@ -107,7 +107,7 @@ static int cachefiles_read_reissue(struct cachefiles_object *object,
 	put_page(backpage2);
 
 	INIT_LIST_HEAD(&monitor->op_link);
-	add_page_wait_queue(backpage, &monitor->monitor);
+	folio_add_wait_queue(page_folio(backpage), &monitor->monitor);
 
 	if (trylock_page(backpage)) {
 		ret = -EIO;
@@ -294,7 +294,7 @@ monitor_backing_page:
 	get_page(backpage);
 	monitor->back_page = backpage;
 	monitor->monitor.private = backpage;
-	add_page_wait_queue(backpage, &monitor->monitor);
+	folio_add_wait_queue(page_folio(backpage), &monitor->monitor);
 	monitor = NULL;
 
 	/* but the page may have been read before the monitor was installed, so
@@ -548,7 +548,7 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
 		get_page(backpage);
 		monitor->back_page = backpage;
 		monitor->monitor.private = backpage;
-		add_page_wait_queue(backpage, &monitor->monitor);
+		folio_add_wait_queue(page_folio(backpage), &monitor->monitor);
 		monitor = NULL;
 
 		/* but the page may have been read before the monitor was

fs/io_uring.c

@@ -3356,7 +3356,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 }
 
 /*
- * This is our waitqueue callback handler, registered through lock_page_async()
+ * This is our waitqueue callback handler, registered through __folio_lock_async()
  * when we initially tried to do the IO with the iocb armed our waitqueue.
  * This gets called when the page is unlocked, and we generally expect that to
  * happen when the page IO is completed and the page is now uptodate. This will

fs/jfs/jfs_metapage.c

@@ -13,6 +13,7 @@
 #include <linux/buffer_head.h>
 #include <linux/mempool.h>
 #include <linux/seq_file.h>
+#include <linux/writeback.h>
 #include "jfs_incore.h"
 #include "jfs_superblock.h"
 #include "jfs_filsys.h"

include/asm-generic/cacheflush.h

@@ -49,9 +49,15 @@ static inline void flush_cache_page(struct vm_area_struct *vma,
 static inline void flush_dcache_page(struct page *page)
 {
 }
+
+static inline void flush_dcache_folio(struct folio *folio) { }
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
 #endif
 
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
+void flush_dcache_folio(struct folio *folio);
+#endif
 
 #ifndef flush_dcache_mmap_lock
 static inline void flush_dcache_mmap_lock(struct address_space *mapping)

include/linux/backing-dev.h

@@ -64,7 +64,7 @@ static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi)
 	return atomic_long_read(&bdi->tot_write_bandwidth);
 }
 
-static inline void __add_wb_stat(struct bdi_writeback *wb,
+static inline void wb_stat_mod(struct bdi_writeback *wb,
 				 enum wb_stat_item item, s64 amount)
 {
 	percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH);
@@ -72,12 +72,12 @@ static inline void __add_wb_stat(struct bdi_writeback *wb,
 
 static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
 {
-	__add_wb_stat(wb, item, 1);
+	wb_stat_mod(wb, item, 1);
 }
 
 static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
 {
-	__add_wb_stat(wb, item, -1);
+	wb_stat_mod(wb, item, -1);
 }
 
 static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)

include/linux/flex_proportions.h

@@ -83,9 +83,10 @@ struct fprop_local_percpu {
 
 int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp);
 void fprop_local_destroy_percpu(struct fprop_local_percpu *pl);
-void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl);
+void __fprop_add_percpu(struct fprop_global *p, struct fprop_local_percpu *pl,
-void __fprop_inc_percpu_max(struct fprop_global *p, struct fprop_local_percpu *pl,
+		long nr);
-			    int max_frac);
+void __fprop_add_percpu_max(struct fprop_global *p,
+		struct fprop_local_percpu *pl, int max_frac, long nr);
 void fprop_fraction_percpu(struct fprop_global *p,
 	struct fprop_local_percpu *pl, unsigned long *numerator,
 	unsigned long *denominator);
@@ -96,7 +97,7 @@ void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)
 	unsigned long flags;
 
 	local_irq_save(flags);
-	__fprop_inc_percpu(p, pl);
+	__fprop_add_percpu(p, pl, 1);
 	local_irq_restore(flags);
 }
 

include/linux/gfp.h

@@ -520,15 +520,11 @@ static inline void arch_free_page(struct page *page, int order) { }
 #ifndef HAVE_ARCH_ALLOC_PAGE
 static inline void arch_alloc_page(struct page *page, int order) { }
 #endif
-#ifndef HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
-static inline int arch_make_page_accessible(struct page *page)
-{
-	return 0;
-}
-#endif
 
 struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
 		nodemask_t *nodemask);
+struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
+		nodemask_t *nodemask);
 
 unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
 				nodemask_t *nodemask, int nr_pages,
@@ -570,6 +566,15 @@ __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
 	return __alloc_pages(gfp_mask, order, nid, NULL);
 }
 
+static inline
+struct folio *__folio_alloc_node(gfp_t gfp, unsigned int order, int nid)
+{
+	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
+	VM_WARN_ON((gfp & __GFP_THISNODE) && !node_online(nid));
+
+	return __folio_alloc(gfp, order, nid, NULL);
+}
+
 /*
  * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
  * prefer the current CPU's closest node. Otherwise node must be valid and
@@ -586,6 +591,7 @@ static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 
 #ifdef CONFIG_NUMA
 struct page *alloc_pages(gfp_t gfp, unsigned int order);
+struct folio *folio_alloc(gfp_t gfp, unsigned order);
 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
 			struct vm_area_struct *vma, unsigned long addr,
 			int node, bool hugepage);
@@ -596,6 +602,10 @@ static inline struct page *alloc_pages(gfp_t gfp_mask, unsigned int order)
 {
 	return alloc_pages_node(numa_node_id(), gfp_mask, order);
 }
+static inline struct folio *folio_alloc(gfp_t gfp, unsigned int order)
+{
+	return __folio_alloc_node(gfp, order, numa_node_id());
+}
 #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
 	alloc_pages(gfp_mask, order)
 #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \

include/linux/highmem-internal.h

@@ -73,6 +73,12 @@ static inline void *kmap_local_page(struct page *page)
 	return __kmap_local_page_prot(page, kmap_prot);
 }
 
+static inline void *kmap_local_folio(struct folio *folio, size_t offset)
+{
+	struct page *page = folio_page(folio, offset / PAGE_SIZE);
+	return __kmap_local_page_prot(page, kmap_prot) + offset % PAGE_SIZE;
+}
+
 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
 {
 	return __kmap_local_page_prot(page, prot);
@@ -171,6 +177,11 @@ static inline void *kmap_local_page(struct page *page)
 	return page_address(page);
 }
 
+static inline void *kmap_local_folio(struct folio *folio, size_t offset)
+{
+	return page_address(&folio->page) + offset;
+}
+
 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
 {
 	return kmap_local_page(page);

include/linux/highmem.h

@@ -96,6 +96,43 @@ static inline void kmap_flush_unused(void);
  */
 static inline void *kmap_local_page(struct page *page);
 
+/**
+ * kmap_local_folio - Map a page in this folio for temporary usage
+ * @folio: The folio containing the page.
+ * @offset: The byte offset within the folio which identifies the page.
+ *
+ * Requires careful handling when nesting multiple mappings because the map
+ * management is stack based. The unmap has to be in the reverse order of
+ * the map operation::
+ *
+ *   addr1 = kmap_local_folio(folio1, offset1);
+ *   addr2 = kmap_local_folio(folio2, offset2);
+ *   ...
+ *   kunmap_local(addr2);
+ *   kunmap_local(addr1);
+ *
+ * Unmapping addr1 before addr2 is invalid and causes malfunction.
+ *
+ * Contrary to kmap() mappings the mapping is only valid in the context of
+ * the caller and cannot be handed to other contexts.
+ *
+ * On CONFIG_HIGHMEM=n kernels and for low memory pages this returns the
+ * virtual address of the direct mapping. Only real highmem pages are
+ * temporarily mapped.
+ *
+ * While it is significantly faster than kmap() for the higmem case it
+ * comes with restrictions about the pointer validity. Only use when really
+ * necessary.
+ *
+ * On HIGHMEM enabled systems mapping a highmem page has the side effect of
+ * disabling migration in order to keep the virtual address stable across
+ * preemption. No caller of kmap_local_folio() can rely on this side effect.
+ *
+ * Context: Can be invoked from any context.
+ * Return: The virtual address of @offset.
+ */
+static inline void *kmap_local_folio(struct folio *folio, size_t offset);
+
 /**
  * kmap_atomic - Atomically map a page for temporary usage - Deprecated!
  * @page:	Pointer to the page to be mapped

include/linux/huge_mm.h

@@ -250,15 +250,6 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 		return NULL;
 }
 
-/**
- * thp_head - Head page of a transparent huge page.
- * @page: Any page (tail, head or regular) found in the page cache.
- */
-static inline struct page *thp_head(struct page *page)
-{
-	return compound_head(page);
-}
-
 /**
  * thp_order - Order of a transparent huge page.
  * @page: Head page of a transparent huge page.
@@ -336,12 +327,6 @@ static inline struct list_head *page_deferred_list(struct page *page)
 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
 
-static inline struct page *thp_head(struct page *page)
-{
-	VM_BUG_ON_PGFLAGS(PageTail(page), page);
-	return page;
-}
-
 static inline unsigned int thp_order(struct page *page)
 {
 	VM_BUG_ON_PGFLAGS(PageTail(page), page);

include/linux/ksm.h

@@ -52,7 +52,7 @@ struct page *ksm_might_need_to_copy(struct page *page,
 			struct vm_area_struct *vma, unsigned long address);
 
 void rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
-void ksm_migrate_page(struct page *newpage, struct page *oldpage);
+void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);
 
 #else  /* !CONFIG_KSM */
 
@@ -83,7 +83,7 @@ static inline void rmap_walk_ksm(struct page *page,
 {
 }
 
-static inline void ksm_migrate_page(struct page *newpage, struct page *oldpage)
+static inline void folio_migrate_ksm(struct folio *newfolio, struct folio *old)
 {
 }
 #endif /* CONFIG_MMU */

include/linux/memcontrol.h

@@ -369,7 +369,7 @@ enum page_memcg_data_flags {
 
 #define MEMCG_DATA_FLAGS_MASK (__NR_MEMCG_DATA_FLAGS - 1)
 
-static inline bool PageMemcgKmem(struct page *page);
+static inline bool folio_memcg_kmem(struct folio *folio);
 
 /*
  * After the initialization objcg->memcg is always pointing at
@@ -384,89 +384,95 @@ static inline struct mem_cgroup *obj_cgroup_memcg(struct obj_cgroup *objcg)
 }
 
 /*
- * __page_memcg - get the memory cgroup associated with a non-kmem page
+ * __folio_memcg - Get the memory cgroup associated with a non-kmem folio
- * @page: a pointer to the page struct
+ * @folio: Pointer to the folio.
  *
- * Returns a pointer to the memory cgroup associated with the page,
+ * Returns a pointer to the memory cgroup associated with the folio,
- * or NULL. This function assumes that the page is known to have a
+ * or NULL. This function assumes that the folio is known to have a
  * proper memory cgroup pointer. It's not safe to call this function
- * against some type of pages, e.g. slab pages or ex-slab pages or
+ * against some type of folios, e.g. slab folios or ex-slab folios or
- * kmem pages.
+ * kmem folios.
  */
-static inline struct mem_cgroup *__page_memcg(struct page *page)
+static inline struct mem_cgroup *__folio_memcg(struct folio *folio)
 {
-	unsigned long memcg_data = page->memcg_data;
+	unsigned long memcg_data = folio->memcg_data;
 
-	VM_BUG_ON_PAGE(PageSlab(page), page);
+	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
-	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_OBJCGS, page);
+	VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio);
-	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, page);
+	VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_KMEM, folio);
 
 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 }
 
 /*
- * __page_objcg - get the object cgroup associated with a kmem page
+ * __folio_objcg - get the object cgroup associated with a kmem folio.
- * @page: a pointer to the page struct
+ * @folio: Pointer to the folio.
  *
- * Returns a pointer to the object cgroup associated with the page,
+ * Returns a pointer to the object cgroup associated with the folio,
- * or NULL. This function assumes that the page is known to have a
+ * or NULL. This function assumes that the folio is known to have a
  * proper object cgroup pointer. It's not safe to call this function
- * against some type of pages, e.g. slab pages or ex-slab pages or
+ * against some type of folios, e.g. slab folios or ex-slab folios or
- * LRU pages.
+ * LRU folios.
  */
-static inline struct obj_cgroup *__page_objcg(struct page *page)
+static inline struct obj_cgroup *__folio_objcg(struct folio *folio)
 {
-	unsigned long memcg_data = page->memcg_data;
+	unsigned long memcg_data = folio->memcg_data;
 
-	VM_BUG_ON_PAGE(PageSlab(page), page);
+	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
-	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_OBJCGS, page);
+	VM_BUG_ON_FOLIO(memcg_data & MEMCG_DATA_OBJCGS, folio);
-	VM_BUG_ON_PAGE(!(memcg_data & MEMCG_DATA_KMEM), page);
+	VM_BUG_ON_FOLIO(!(memcg_data & MEMCG_DATA_KMEM), folio);
 
 	return (struct obj_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 }
 
 /*
- * page_memcg - get the memory cgroup associated with a page
+ * folio_memcg - Get the memory cgroup associated with a folio.
- * @page: a pointer to the page struct
+ * @folio: Pointer to the folio.
  *
- * Returns a pointer to the memory cgroup associated with the page,
+ * Returns a pointer to the memory cgroup associated with the folio,
- * or NULL. This function assumes that the page is known to have a
+ * or NULL. This function assumes that the folio is known to have a
  * proper memory cgroup pointer. It's not safe to call this function
- * against some type of pages, e.g. slab pages or ex-slab pages.
+ * against some type of folios, e.g. slab folios or ex-slab folios.
  *
- * For a non-kmem page any of the following ensures page and memcg binding
+ * For a non-kmem folio any of the following ensures folio and memcg binding
  * stability:
  *
- * - the page lock
+ * - the folio lock
  * - LRU isolation
  * - lock_page_memcg()
  * - exclusive reference
  *
- * For a kmem page a caller should hold an rcu read lock to protect memcg
+ * For a kmem folio a caller should hold an rcu read lock to protect memcg
- * associated with a kmem page from being released.
+ * associated with a kmem folio from being released.
  */
-static inline struct mem_cgroup *page_memcg(struct page *page)
+static inline struct mem_cgroup *folio_memcg(struct folio *folio)
 {
-	if (PageMemcgKmem(page))
+	if (folio_memcg_kmem(folio))
-		return obj_cgroup_memcg(__page_objcg(page));
+		return obj_cgroup_memcg(__folio_objcg(folio));
-	else
+	return __folio_memcg(folio);
-		return __page_memcg(page);
 }
 
-/*
+static inline struct mem_cgroup *page_memcg(struct page *page)
- * page_memcg_rcu - locklessly get the memory cgroup associated with a page
- * @page: a pointer to the page struct
- *
- * Returns a pointer to the memory cgroup associated with the page,
- * or NULL. This function assumes that the page is known to have a
- * proper memory cgroup pointer. It's not safe to call this function
- * against some type of pages, e.g. slab pages or ex-slab pages.
- */
-static inline struct mem_cgroup *page_memcg_rcu(struct page *page)
 {
-	unsigned long memcg_data = READ_ONCE(page->memcg_data);
+	return folio_memcg(page_folio(page));
+}
 
-	VM_BUG_ON_PAGE(PageSlab(page), page);
+/**
+ * folio_memcg_rcu - Locklessly get the memory cgroup associated with a folio.
+ * @folio: Pointer to the folio.
+ *
+ * This function assumes that the folio is known to have a
+ * proper memory cgroup pointer. It's not safe to call this function
+ * against some type of folios, e.g. slab folios or ex-slab folios.
+ *
+ * Return: A pointer to the memory cgroup associated with the folio,
+ * or NULL.
+ */
+static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
+{
+	unsigned long memcg_data = READ_ONCE(folio->memcg_data);
+
+	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
 	if (memcg_data & MEMCG_DATA_KMEM) {
@@ -523,17 +529,18 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
 
 #ifdef CONFIG_MEMCG_KMEM
 /*
- * PageMemcgKmem - check if the page has MemcgKmem flag set
+ * folio_memcg_kmem - Check if the folio has the memcg_kmem flag set.
- * @page: a pointer to the page struct
+ * @folio: Pointer to the folio.
  *
- * Checks if the page has MemcgKmem flag set. The caller must ensure that
+ * Checks if the folio has MemcgKmem flag set. The caller must ensure
- * the page has an associated memory cgroup. It's not safe to call this function
+ * that the folio has an associated memory cgroup. It's not safe to call
- * against some types of pages, e.g. slab pages.
+ * this function against some types of folios, e.g. slab folios.
  */
-static inline bool PageMemcgKmem(struct page *page)
+static inline bool folio_memcg_kmem(struct folio *folio)
 {
-	VM_BUG_ON_PAGE(page->memcg_data & MEMCG_DATA_OBJCGS, page);
+	VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page);
-	return page->memcg_data & MEMCG_DATA_KMEM;
+	VM_BUG_ON_FOLIO(folio->memcg_data & MEMCG_DATA_OBJCGS, folio);
+	return folio->memcg_data & MEMCG_DATA_KMEM;
 }
 
 /*
@@ -577,7 +584,7 @@ static inline struct obj_cgroup **page_objcgs_check(struct page *page)
 }
 
 #else
-static inline bool PageMemcgKmem(struct page *page)
+static inline bool folio_memcg_kmem(struct folio *folio)
 {
 	return false;
 }
@@ -593,6 +600,11 @@ static inline struct obj_cgroup **page_objcgs_check(struct page *page)
 }
 #endif
 
+static inline bool PageMemcgKmem(struct page *page)
+{
+	return folio_memcg_kmem(page_folio(page));
+}
+
 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
 	return (memcg == root_mem_cgroup);
@@ -684,26 +696,47 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
 		page_counter_read(&memcg->memory);
 }
 
-int __mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp);
-			gfp_t gfp_mask);
+
-static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+/**
-				    gfp_t gfp_mask)
+ * mem_cgroup_charge - Charge a newly allocated folio to a cgroup.
+ * @folio: Folio to charge.
+ * @mm: mm context of the allocating task.
+ * @gfp: Reclaim mode.
+ *
+ * Try to charge @folio to the memcg that @mm belongs to, reclaiming
+ * pages according to @gfp if necessary.  If @mm is NULL, try to
+ * charge to the active memcg.
+ *
+ * Do not use this for folios allocated for swapin.
+ *
+ * Return: 0 on success. Otherwise, an error code is returned.
+ */
+static inline int mem_cgroup_charge(struct folio *folio, struct mm_struct *mm,
+				    gfp_t gfp)
 {
 	if (mem_cgroup_disabled())
 		return 0;
-	return __mem_cgroup_charge(page, mm, gfp_mask);
+	return __mem_cgroup_charge(folio, mm, gfp);
 }
 
 int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
 				  gfp_t gfp, swp_entry_t entry);
 void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry);
 
-void __mem_cgroup_uncharge(struct page *page);
+void __mem_cgroup_uncharge(struct folio *folio);
-static inline void mem_cgroup_uncharge(struct page *page)
+
+/**
+ * mem_cgroup_uncharge - Uncharge a folio.
+ * @folio: Folio to uncharge.
+ *
+ * Uncharge a folio previously charged with mem_cgroup_charge().
+ */
+static inline void mem_cgroup_uncharge(struct folio *folio)
 {
 	if (mem_cgroup_disabled())
 		return;
-	__mem_cgroup_uncharge(page);
+	__mem_cgroup_uncharge(folio);
 }
 
 void __mem_cgroup_uncharge_list(struct list_head *page_list);
@@ -714,7 +747,7 @@ static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 	__mem_cgroup_uncharge_list(page_list);
 }
 
-void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
+void mem_cgroup_migrate(struct folio *old, struct folio *new);
 
 /**
  * mem_cgroup_lruvec - get the lru list vector for a memcg & node
@@ -753,33 +786,33 @@ out:
 }
 
 /**
- * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
+ * folio_lruvec - return lruvec for isolating/putting an LRU folio
- * @page: the page
+ * @folio: Pointer to the folio.
  *
- * This function relies on page->mem_cgroup being stable.
+ * This function relies on folio->mem_cgroup being stable.
  */
-static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page)
+static inline struct lruvec *folio_lruvec(struct folio *folio)
 {
-	pg_data_t *pgdat = page_pgdat(page);
+	struct mem_cgroup *memcg = folio_memcg(folio);
-	struct mem_cgroup *memcg = page_memcg(page);
 
-	VM_WARN_ON_ONCE_PAGE(!memcg && !mem_cgroup_disabled(), page);
+	VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled(), folio);
-	return mem_cgroup_lruvec(memcg, pgdat);
+	return mem_cgroup_lruvec(memcg, folio_pgdat(folio));
 }
 
 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 
 struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm);
 
-struct lruvec *lock_page_lruvec(struct page *page);
+struct lruvec *folio_lruvec_lock(struct folio *folio);
-struct lruvec *lock_page_lruvec_irq(struct page *page);
+struct lruvec *folio_lruvec_lock_irq(struct folio *folio);
-struct lruvec *lock_page_lruvec_irqsave(struct page *page,
+struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
 						unsigned long *flags);
 
 #ifdef CONFIG_DEBUG_VM
-void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page);
+void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio);
 #else
-static inline void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+static inline
+void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
 {
 }
 #endif
@@ -947,6 +980,8 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
 extern bool cgroup_memory_noswap;
 #endif
 
+void folio_memcg_lock(struct folio *folio);
+void folio_memcg_unlock(struct folio *folio);
 void lock_page_memcg(struct page *page);
 void unlock_page_memcg(struct page *page);
 
@@ -1115,12 +1150,17 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
 #define MEM_CGROUP_ID_SHIFT	0
 #define MEM_CGROUP_ID_MAX	0
 
+static inline struct mem_cgroup *folio_memcg(struct folio *folio)
+{
+	return NULL;
+}
+
 static inline struct mem_cgroup *page_memcg(struct page *page)
 {
 	return NULL;
 }
 
-static inline struct mem_cgroup *page_memcg_rcu(struct page *page)
+static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
 {
 	WARN_ON_ONCE(!rcu_read_lock_held());
 	return NULL;
@@ -1131,6 +1171,11 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
 	return NULL;
 }
 
+static inline bool folio_memcg_kmem(struct folio *folio)
+{
+	return false;
+}
+
 static inline bool PageMemcgKmem(struct page *page)
 {
 	return false;
@@ -1179,8 +1224,8 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
 	return false;
 }
 
-static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+static inline int mem_cgroup_charge(struct folio *folio,
-				    gfp_t gfp_mask)
+		struct mm_struct *mm, gfp_t gfp)
 {
 	return 0;
 }
@@ -1195,7 +1240,7 @@ static inline void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry)
 {
 }
 
-static inline void mem_cgroup_uncharge(struct page *page)
+static inline void mem_cgroup_uncharge(struct folio *folio)
 {
 }
 
@@ -1203,7 +1248,7 @@ static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 {
 }
 
-static inline void mem_cgroup_migrate(struct page *old, struct page *new)
+static inline void mem_cgroup_migrate(struct folio *old, struct folio *new)
 {
 }
 
@@ -1213,14 +1258,14 @@ static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page)
+static inline struct lruvec *folio_lruvec(struct folio *folio)
 {
-	pg_data_t *pgdat = page_pgdat(page);
+	struct pglist_data *pgdat = folio_pgdat(folio);
-
 	return &pgdat->__lruvec;
 }
 
-static inline void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+static inline
+void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
 {
 }
 
@@ -1250,26 +1295,26 @@ static inline void mem_cgroup_put(struct mem_cgroup *memcg)
 {
 }
 
-static inline struct lruvec *lock_page_lruvec(struct page *page)
+static inline struct lruvec *folio_lruvec_lock(struct folio *folio)
 {
-	struct pglist_data *pgdat = page_pgdat(page);
+	struct pglist_data *pgdat = folio_pgdat(folio);
 
 	spin_lock(&pgdat->__lruvec.lru_lock);
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *lock_page_lruvec_irq(struct page *page)
+static inline struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
 {
-	struct pglist_data *pgdat = page_pgdat(page);
+	struct pglist_data *pgdat = folio_pgdat(folio);
 
 	spin_lock_irq(&pgdat->__lruvec.lru_lock);
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *lock_page_lruvec_irqsave(struct page *page,
+static inline struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
 		unsigned long *flagsp)
 {
-	struct pglist_data *pgdat = page_pgdat(page);
+	struct pglist_data *pgdat = folio_pgdat(folio);
 
 	spin_lock_irqsave(&pgdat->__lruvec.lru_lock, *flagsp);
 	return &pgdat->__lruvec;
@@ -1356,6 +1401,14 @@ static inline void unlock_page_memcg(struct page *page)
 {
 }
 
+static inline void folio_memcg_lock(struct folio *folio)
+{
+}
+
+static inline void folio_memcg_unlock(struct folio *folio)
+{
+}
+
 static inline void mem_cgroup_handle_over_high(void)
 {
 }
@@ -1517,38 +1570,39 @@ static inline void unlock_page_lruvec_irqrestore(struct lruvec *lruvec,
 }
 
 /* Test requires a stable page->memcg binding, see page_memcg() */
-static inline bool page_matches_lruvec(struct page *page, struct lruvec *lruvec)
+static inline bool folio_matches_lruvec(struct folio *folio,
+		struct lruvec *lruvec)
 {
-	return lruvec_pgdat(lruvec) == page_pgdat(page) &&
+	return lruvec_pgdat(lruvec) == folio_pgdat(folio) &&
-	       lruvec_memcg(lruvec) == page_memcg(page);
+	       lruvec_memcg(lruvec) == folio_memcg(folio);
 }
 
 /* Don't lock again iff page's lruvec locked */
-static inline struct lruvec *relock_page_lruvec_irq(struct page *page,
+static inline struct lruvec *folio_lruvec_relock_irq(struct folio *folio,
 		struct lruvec *locked_lruvec)
 {
 	if (locked_lruvec) {
-		if (page_matches_lruvec(page, locked_lruvec))
+		if (folio_matches_lruvec(folio, locked_lruvec))
 			return locked_lruvec;
 
 		unlock_page_lruvec_irq(locked_lruvec);
 	}
 
-	return lock_page_lruvec_irq(page);
+	return folio_lruvec_lock_irq(folio);
 }
 
 /* Don't lock again iff page's lruvec locked */
-static inline struct lruvec *relock_page_lruvec_irqsave(struct page *page,
+static inline struct lruvec *folio_lruvec_relock_irqsave(struct folio *folio,
 		struct lruvec *locked_lruvec, unsigned long *flags)
 {
 	if (locked_lruvec) {
-		if (page_matches_lruvec(page, locked_lruvec))
+		if (folio_matches_lruvec(folio, locked_lruvec))
 			return locked_lruvec;
 
 		unlock_page_lruvec_irqrestore(locked_lruvec, *flags);
 	}
 
-	return lock_page_lruvec_irqsave(page, flags);
+	return folio_lruvec_lock_irqsave(folio, flags);
 }
 
 #ifdef CONFIG_CGROUP_WRITEBACK
@@ -1558,17 +1612,17 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 			 unsigned long *pheadroom, unsigned long *pdirty,
 			 unsigned long *pwriteback);
 
-void mem_cgroup_track_foreign_dirty_slowpath(struct page *page,
+void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio,
 					     struct bdi_writeback *wb);
 
-static inline void mem_cgroup_track_foreign_dirty(struct page *page,
+static inline void mem_cgroup_track_foreign_dirty(struct folio *folio,
 						  struct bdi_writeback *wb)
 {
 	if (mem_cgroup_disabled())
 		return;
 
-	if (unlikely(&page_memcg(page)->css != wb->memcg_css))
+	if (unlikely(&folio_memcg(folio)->css != wb->memcg_css))
-		mem_cgroup_track_foreign_dirty_slowpath(page, wb);
+		mem_cgroup_track_foreign_dirty_slowpath(folio, wb);
 }
 
 void mem_cgroup_flush_foreign(struct bdi_writeback *wb);
@@ -1588,7 +1642,7 @@ static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
 {
 }
 
-static inline void mem_cgroup_track_foreign_dirty(struct page *page,
+static inline void mem_cgroup_track_foreign_dirty(struct folio *folio,
 						  struct bdi_writeback *wb)
 {
 }

include/linux/migrate.h

@@ -57,6 +57,10 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping,
 				  struct page *newpage, struct page *page);
 extern int migrate_page_move_mapping(struct address_space *mapping,
 		struct page *newpage, struct page *page, int extra_count);
+void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
+void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
+int folio_migrate_mapping(struct address_space *mapping,
+		struct folio *newfolio, struct folio *folio, int extra_count);
 #else
 
 static inline void putback_movable_pages(struct list_head *l) {}

include/linux/mm.h

@@ -36,10 +36,7 @@
 struct mempolicy;
 struct anon_vma;
 struct anon_vma_chain;
-struct file_ra_state;
 struct user_struct;
-struct writeback_control;
-struct bdi_writeback;
 struct pt_regs;
 
 extern int sysctl_page_lock_unfairness;
@@ -216,13 +213,6 @@ int overcommit_kbytes_handler(struct ctl_table *, int, void *, size_t *,
 		loff_t *);
 int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
 		loff_t *);
-/*
- * Any attempt to mark this function as static leads to build failure
- * when CONFIG_DEBUG_INFO_BTF is enabled because __add_to_page_cache_locked()
- * is referred to by BPF code. This must be visible for error injection.
- */
-int __add_to_page_cache_locked(struct page *page, struct address_space *mapping,
-		pgoff_t index, gfp_t gfp, void **shadowp);
 
 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
@@ -748,13 +738,18 @@ static inline int put_page_testzero(struct page *page)
 	return page_ref_dec_and_test(page);
 }
 
+static inline int folio_put_testzero(struct folio *folio)
+{
+	return put_page_testzero(&folio->page);
+}
+
 /*
  * Try to grab a ref unless the page has a refcount of zero, return false if
  * that is the case.
  * This can be called when MMU is off so it must not access
  * any of the virtual mappings.
  */
-static inline int get_page_unless_zero(struct page *page)
+static inline bool get_page_unless_zero(struct page *page)
 {
 	return page_ref_add_unless(page, 1, 0);
 }
@@ -907,7 +902,7 @@ void __put_page(struct page *page);
 void put_pages_list(struct list_head *pages);
 
 void split_page(struct page *page, unsigned int order);
-void copy_huge_page(struct page *dst, struct page *src);
+void folio_copy(struct folio *dst, struct folio *src);
 
 /*
  * Compound pages have a destructor function.  Provide a
@@ -950,6 +945,20 @@ static inline unsigned int compound_order(struct page *page)
 	return page[1].compound_order;
 }
 
+/**
+ * folio_order - The allocation order of a folio.
+ * @folio: The folio.
+ *
+ * A folio is composed of 2^order pages.  See get_order() for the definition
+ * of order.
+ *
+ * Return: The order of the folio.
+ */
+static inline unsigned int folio_order(struct folio *folio)
+{
+	return compound_order(&folio->page);
+}
+
 static inline bool hpage_pincount_available(struct page *page)
 {
 	/*
@@ -1131,6 +1140,11 @@ static inline enum zone_type page_zonenum(const struct page *page)
 	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 }
 
+static inline enum zone_type folio_zonenum(const struct folio *folio)
+{
+	return page_zonenum(&folio->page);
+}
+
 #ifdef CONFIG_ZONE_DEVICE
 static inline bool is_zone_device_page(const struct page *page)
 {
@@ -1200,18 +1214,26 @@ static inline bool is_pci_p2pdma_page(const struct page *page)
 }
 
 /* 127: arbitrary random number, small enough to assemble well */
-#define page_ref_zero_or_close_to_overflow(page) \
+#define folio_ref_zero_or_close_to_overflow(folio) \
-	((unsigned int) page_ref_count(page) + 127u <= 127u)
+	((unsigned int) folio_ref_count(folio) + 127u <= 127u)
+
+/**
+ * folio_get - Increment the reference count on a folio.
+ * @folio: The folio.
+ *
+ * Context: May be called in any context, as long as you know that
+ * you have a refcount on the folio.  If you do not already have one,
+ * folio_try_get() may be the right interface for you to use.
+ */
+static inline void folio_get(struct folio *folio)
+{
+	VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio);
+	folio_ref_inc(folio);
+}
 
 static inline void get_page(struct page *page)
 {
-	page = compound_head(page);
+	folio_get(page_folio(page));
-	/*
-	 * Getting a normal page or the head of a compound page
-	 * requires to already have an elevated page->_refcount.
-	 */
-	VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page);
-	page_ref_inc(page);
 }
 
 bool __must_check try_grab_page(struct page *page, unsigned int flags);
@@ -1228,9 +1250,28 @@ static inline __must_check bool try_get_page(struct page *page)
 	return true;
 }
 
+/**
+ * folio_put - Decrement the reference count on a folio.
+ * @folio: The folio.
+ *
+ * If the folio's reference count reaches zero, the memory will be
+ * released back to the page allocator and may be used by another
+ * allocation immediately.  Do not access the memory or the struct folio
+ * after calling folio_put() unless you can be sure that it wasn't the
+ * last reference.
+ *
+ * Context: May be called in process or interrupt context, but not in NMI
+ * context.  May be called while holding a spinlock.
+ */
+static inline void folio_put(struct folio *folio)
+{
+	if (folio_put_testzero(folio))
+		__put_page(&folio->page);
+}
+
 static inline void put_page(struct page *page)
 {
-	page = compound_head(page);
+	struct folio *folio = page_folio(page);
 
 	/*
 	 * For devmap managed pages we need to catch refcount transition from
@@ -1238,13 +1279,12 @@ static inline void put_page(struct page *page)
 	 * need to inform the device driver through callback. See
 	 * include/linux/memremap.h and HMM for details.
 	 */
-	if (page_is_devmap_managed(page)) {
+	if (page_is_devmap_managed(&folio->page)) {
-		put_devmap_managed_page(page);
+		put_devmap_managed_page(&folio->page);
 		return;
 	}
 
-	if (put_page_testzero(page))
+	folio_put(folio);
-		__put_page(page);
 }
 
 /*
@@ -1379,6 +1419,11 @@ static inline int page_to_nid(const struct page *page)
 }
 #endif
 
+static inline int folio_nid(const struct folio *folio)
+{
+	return page_to_nid(&folio->page);
+}
+
 #ifdef CONFIG_NUMA_BALANCING
 static inline int cpu_pid_to_cpupid(int cpu, int pid)
 {
@@ -1546,6 +1591,16 @@ static inline pg_data_t *page_pgdat(const struct page *page)
 	return NODE_DATA(page_to_nid(page));
 }
 
+static inline struct zone *folio_zone(const struct folio *folio)
+{
+	return page_zone(&folio->page);
+}
+
+static inline pg_data_t *folio_pgdat(const struct folio *folio)
+{
+	return page_pgdat(&folio->page);
+}
+
 #ifdef SECTION_IN_PAGE_FLAGS
 static inline void set_page_section(struct page *page, unsigned long section)
 {
@@ -1559,6 +1614,20 @@ static inline unsigned long page_to_section(const struct page *page)
 }
 #endif
 
+/**
+ * folio_pfn - Return the Page Frame Number of a folio.
+ * @folio: The folio.
+ *
+ * A folio may contain multiple pages.  The pages have consecutive
+ * Page Frame Numbers.
+ *
+ * Return: The Page Frame Number of the first page in the folio.
+ */
+static inline unsigned long folio_pfn(struct folio *folio)
+{
+	return page_to_pfn(&folio->page);
+}
+
 /* MIGRATE_CMA and ZONE_MOVABLE do not allow pin pages */
 #ifdef CONFIG_MIGRATION
 static inline bool is_pinnable_page(struct page *page)
@@ -1595,6 +1664,89 @@ static inline void set_page_links(struct page *page, enum zone_type zone,
 #endif
 }
 
+/**
+ * folio_nr_pages - The number of pages in the folio.
+ * @folio: The folio.
+ *
+ * Return: A positive power of two.
+ */
+static inline long folio_nr_pages(struct folio *folio)
+{
+	return compound_nr(&folio->page);
+}
+
+/**
+ * folio_next - Move to the next physical folio.
+ * @folio: The folio we're currently operating on.
+ *
+ * If you have physically contiguous memory which may span more than
+ * one folio (eg a &struct bio_vec), use this function to move from one
+ * folio to the next.  Do not use it if the memory is only virtually
+ * contiguous as the folios are almost certainly not adjacent to each
+ * other.  This is the folio equivalent to writing ``page++``.
+ *
+ * Context: We assume that the folios are refcounted and/or locked at a
+ * higher level and do not adjust the reference counts.
+ * Return: The next struct folio.
+ */
+static inline struct folio *folio_next(struct folio *folio)
+{
+	return (struct folio *)folio_page(folio, folio_nr_pages(folio));
+}
+
+/**
+ * folio_shift - The size of the memory described by this folio.
+ * @folio: The folio.
+ *
+ * A folio represents a number of bytes which is a power-of-two in size.
+ * This function tells you which power-of-two the folio is.  See also
+ * folio_size() and folio_order().
+ *
+ * Context: The caller should have a reference on the folio to prevent
+ * it from being split.  It is not necessary for the folio to be locked.
+ * Return: The base-2 logarithm of the size of this folio.
+ */
+static inline unsigned int folio_shift(struct folio *folio)
+{
+	return PAGE_SHIFT + folio_order(folio);
+}
+
+/**
+ * folio_size - The number of bytes in a folio.
+ * @folio: The folio.
+ *
+ * Context: The caller should have a reference on the folio to prevent
+ * it from being split.  It is not necessary for the folio to be locked.
+ * Return: The number of bytes in this folio.
+ */
+static inline size_t folio_size(struct folio *folio)
+{
+	return PAGE_SIZE << folio_order(folio);
+}
+
+#ifndef HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
+static inline int arch_make_page_accessible(struct page *page)
+{
+	return 0;
+}
+#endif
+
+#ifndef HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
+static inline int arch_make_folio_accessible(struct folio *folio)
+{
+	int ret;
+	long i, nr = folio_nr_pages(folio);
+
+	for (i = 0; i < nr; i++) {
+		ret = arch_make_page_accessible(folio_page(folio, i));
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+#endif
+
 /*
  * Some inline functions in vmstat.h depend on page_zone()
  */
@@ -1635,19 +1787,6 @@ void page_address_init(void);
 
 extern void *page_rmapping(struct page *page);
 extern struct anon_vma *page_anon_vma(struct page *page);
-extern struct address_space *page_mapping(struct page *page);
-
-extern struct address_space *__page_file_mapping(struct page *);
-
-static inline
-struct address_space *page_file_mapping(struct page *page)
-{
-	if (unlikely(PageSwapCache(page)))
-		return __page_file_mapping(page);
-
-	return page->mapping;
-}
-
 extern pgoff_t __page_file_index(struct page *page);
 
 /*
@@ -1662,7 +1801,7 @@ static inline pgoff_t page_index(struct page *page)
 }
 
 bool page_mapped(struct page *page);
-struct address_space *page_mapping(struct page *page);
+bool folio_mapped(struct folio *folio);
 
 /*
  * Return true only if the page has been allocated with
@@ -1700,6 +1839,7 @@ extern void pagefault_out_of_memory(void);
 
 #define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
 #define offset_in_thp(page, p)	((unsigned long)(p) & (thp_size(page) - 1))
+#define offset_in_folio(folio, p) ((unsigned long)(p) & (folio_size(folio) - 1))
 
 /*
  * Flags passed to show_mem() and show_free_areas() to suppress output in
@@ -1854,20 +1994,9 @@ extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
 extern void do_invalidatepage(struct page *page, unsigned int offset,
 			      unsigned int length);
 
-int redirty_page_for_writepage(struct writeback_control *wbc,
+bool folio_mark_dirty(struct folio *folio);
-				struct page *page);
+bool set_page_dirty(struct page *page);
-void account_page_cleaned(struct page *page, struct address_space *mapping,
-			  struct bdi_writeback *wb);
-int set_page_dirty(struct page *page);
 int set_page_dirty_lock(struct page *page);
-void __cancel_dirty_page(struct page *page);
-static inline void cancel_dirty_page(struct page *page)
-{
-	/* Avoid atomic ops, locking, etc. when not actually needed. */
-	if (PageDirty(page))
-		__cancel_dirty_page(page);
-}
-int clear_page_dirty_for_io(struct page *page);
 
 int get_cmdline(struct task_struct *task, char *buffer, int buflen);
 
@@ -2659,10 +2788,6 @@ extern vm_fault_t filemap_map_pages(struct vm_fault *vmf,
 		pgoff_t start_pgoff, pgoff_t end_pgoff);
 extern vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf);
 
-/* mm/page-writeback.c */
-int __must_check write_one_page(struct page *page);
-void task_dirty_inc(struct task_struct *tsk);
-
 extern unsigned long stack_guard_gap;
 /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);

include/linux/mm_inline.h

@@ -6,27 +6,33 @@
 #include <linux/swap.h>
 
 /**
- * page_is_file_lru - should the page be on a file LRU or anon LRU?
+ * folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
- * @page: the page to test
+ * @folio: The folio to test.
- *
- * Returns 1 if @page is a regular filesystem backed page cache page or a lazily
- * freed anonymous page (e.g. via MADV_FREE).  Returns 0 if @page is a normal
- * anonymous page, a tmpfs page or otherwise ram or swap backed page.  Used by
- * functions that manipulate the LRU lists, to sort a page onto the right LRU
- * list.
  *
  * We would like to get this info without a page flag, but the state
- * needs to survive until the page is last deleted from the LRU, which
+ * needs to survive until the folio is last deleted from the LRU, which
  * could be as far down as __page_cache_release.
+ *
+ * Return: An integer (not a boolean!) used to sort a folio onto the
+ * right LRU list and to account folios correctly.
+ * 1 if @folio is a regular filesystem backed page cache folio
+ * or a lazily freed anonymous folio (e.g. via MADV_FREE).
+ * 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise
+ * ram or swap backed folio.
  */
+static inline int folio_is_file_lru(struct folio *folio)
+{
+	return !folio_test_swapbacked(folio);
+}
+
 static inline int page_is_file_lru(struct page *page)
 {
-	return !PageSwapBacked(page);
+	return folio_is_file_lru(page_folio(page));
 }
 
 static __always_inline void update_lru_size(struct lruvec *lruvec,
 				enum lru_list lru, enum zone_type zid,
-				int nr_pages)
+				long nr_pages)
 {
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 
@@ -39,69 +45,94 @@ static __always_inline void update_lru_size(struct lruvec *lruvec,
 }
 
 /**
- * __clear_page_lru_flags - clear page lru flags before releasing a page
+ * __folio_clear_lru_flags - Clear page lru flags before releasing a page.
- * @page: the page that was on lru and now has a zero reference
+ * @folio: The folio that was on lru and now has a zero reference.
  */
-static __always_inline void __clear_page_lru_flags(struct page *page)
+static __always_inline void __folio_clear_lru_flags(struct folio *folio)
 {
-	VM_BUG_ON_PAGE(!PageLRU(page), page);
+	VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);
 
-	__ClearPageLRU(page);
+	__folio_clear_lru(folio);
 
 	/* this shouldn't happen, so leave the flags to bad_page() */
-	if (PageActive(page) && PageUnevictable(page))
+	if (folio_test_active(folio) && folio_test_unevictable(folio))
 		return;
 
-	__ClearPageActive(page);
+	__folio_clear_active(folio);
-	__ClearPageUnevictable(page);
+	__folio_clear_unevictable(folio);
+}
+
+static __always_inline void __clear_page_lru_flags(struct page *page)
+{
+	__folio_clear_lru_flags(page_folio(page));
 }
 
 /**
- * page_lru - which LRU list should a page be on?
+ * folio_lru_list - Which LRU list should a folio be on?
- * @page: the page to test
+ * @folio: The folio to test.
  *
- * Returns the LRU list a page should be on, as an index
+ * Return: The LRU list a folio should be on, as an index
  * into the array of LRU lists.
  */
-static __always_inline enum lru_list page_lru(struct page *page)
+static __always_inline enum lru_list folio_lru_list(struct folio *folio)
 {
 	enum lru_list lru;
 
-	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
+	VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
 
-	if (PageUnevictable(page))
+	if (folio_test_unevictable(folio))
 		return LRU_UNEVICTABLE;
 
-	lru = page_is_file_lru(page) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
+	lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
-	if (PageActive(page))
+	if (folio_test_active(folio))
 		lru += LRU_ACTIVE;
 
 	return lru;
 }
 
+static __always_inline
+void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
+{
+	enum lru_list lru = folio_lru_list(folio);
+
+	update_lru_size(lruvec, lru, folio_zonenum(folio),
+			folio_nr_pages(folio));
+	list_add(&folio->lru, &lruvec->lists[lru]);
+}
+
 static __always_inline void add_page_to_lru_list(struct page *page,
 				struct lruvec *lruvec)
 {
-	enum lru_list lru = page_lru(page);
+	lruvec_add_folio(lruvec, page_folio(page));
+}
 
-	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
+static __always_inline
-	list_add(&page->lru, &lruvec->lists[lru]);
+void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
+{
+	enum lru_list lru = folio_lru_list(folio);
+
+	update_lru_size(lruvec, lru, folio_zonenum(folio),
+			folio_nr_pages(folio));
+	list_add_tail(&folio->lru, &lruvec->lists[lru]);
 }
 
 static __always_inline void add_page_to_lru_list_tail(struct page *page,
 				struct lruvec *lruvec)
 {
-	enum lru_list lru = page_lru(page);
+	lruvec_add_folio_tail(lruvec, page_folio(page));
+}
 
-	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
+static __always_inline
-	list_add_tail(&page->lru, &lruvec->lists[lru]);
+void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
+{
+	list_del(&folio->lru);
+	update_lru_size(lruvec, folio_lru_list(folio), folio_zonenum(folio),
+			-folio_nr_pages(folio));
 }
 
 static __always_inline void del_page_from_lru_list(struct page *page,
 				struct lruvec *lruvec)
 {
-	list_del(&page->lru);
+	lruvec_del_folio(lruvec, page_folio(page));
-	update_lru_size(lruvec, page_lru(page), page_zonenum(page),
-			-thp_nr_pages(page));
 }
 #endif

include/linux/mm_types.h

@@ -239,6 +239,72 @@ struct page {
 #endif
 } _struct_page_alignment;
 
+/**
+ * struct folio - Represents a contiguous set of bytes.
+ * @flags: Identical to the page flags.
+ * @lru: Least Recently Used list; tracks how recently this folio was used.
+ * @mapping: The file this page belongs to, or refers to the anon_vma for
+ *    anonymous memory.
+ * @index: Offset within the file, in units of pages.  For anonymous memory,
+ *    this is the index from the beginning of the mmap.
+ * @private: Filesystem per-folio data (see folio_attach_private()).
+ *    Used for swp_entry_t if folio_test_swapcache().
+ * @_mapcount: Do not access this member directly.  Use folio_mapcount() to
+ *    find out how many times this folio is mapped by userspace.
+ * @_refcount: Do not access this member directly.  Use folio_ref_count()
+ *    to find how many references there are to this folio.
+ * @memcg_data: Memory Control Group data.
+ *
+ * A folio is a physically, virtually and logically contiguous set
+ * of bytes.  It is a power-of-two in size, and it is aligned to that
+ * same power-of-two.  It is at least as large as %PAGE_SIZE.  If it is
+ * in the page cache, it is at a file offset which is a multiple of that
+ * power-of-two.  It may be mapped into userspace at an address which is
+ * at an arbitrary page offset, but its kernel virtual address is aligned
+ * to its size.
+ */
+struct folio {
+	/* private: don't document the anon union */
+	union {
+		struct {
+	/* public: */
+			unsigned long flags;
+			struct list_head lru;
+			struct address_space *mapping;
+			pgoff_t index;
+			void *private;
+			atomic_t _mapcount;
+			atomic_t _refcount;
+#ifdef CONFIG_MEMCG
+			unsigned long memcg_data;
+#endif
+	/* private: the union with struct page is transitional */
+		};
+		struct page page;
+	};
+};
+
+static_assert(sizeof(struct page) == sizeof(struct folio));
+#define FOLIO_MATCH(pg, fl)						\
+	static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl))
+FOLIO_MATCH(flags, flags);
+FOLIO_MATCH(lru, lru);
+FOLIO_MATCH(compound_head, lru);
+FOLIO_MATCH(index, index);
+FOLIO_MATCH(private, private);
+FOLIO_MATCH(_mapcount, _mapcount);
+FOLIO_MATCH(_refcount, _refcount);
+#ifdef CONFIG_MEMCG
+FOLIO_MATCH(memcg_data, memcg_data);
+#endif
+#undef FOLIO_MATCH
+
+static inline atomic_t *folio_mapcount_ptr(struct folio *folio)
+{
+	struct page *tail = &folio->page + 1;
+	return &tail->compound_mapcount;
+}
+
 static inline atomic_t *compound_mapcount_ptr(struct page *page)
 {
 	return &page[1].compound_mapcount;
@@ -257,6 +323,12 @@ static inline atomic_t *compound_pincount_ptr(struct page *page)
 #define PAGE_FRAG_CACHE_MAX_SIZE	__ALIGN_MASK(32768, ~PAGE_MASK)
 #define PAGE_FRAG_CACHE_MAX_ORDER	get_order(PAGE_FRAG_CACHE_MAX_SIZE)
 
+/*
+ * page_private can be used on tail pages.  However, PagePrivate is only
+ * checked by the VM on the head page.  So page_private on the tail pages
+ * should be used for data that's ancillary to the head page (eg attaching
+ * buffer heads to tail pages after attaching buffer heads to the head page)
+ */
 #define page_private(page)		((page)->private)
 
 static inline void set_page_private(struct page *page, unsigned long private)
@@ -264,6 +336,11 @@ static inline void set_page_private(struct page *page, unsigned long private)
 	page->private = private;
 }
 
+static inline void *folio_get_private(struct folio *folio)
+{
+	return folio->private;
+}
+
 struct page_frag_cache {
 	void * va;
 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)

include/linux/mmdebug.h

@@ -22,6 +22,13 @@ void dump_mm(const struct mm_struct *mm);
 			BUG();						\
 		}							\
 	} while (0)
+#define VM_BUG_ON_FOLIO(cond, folio)					\
+	do {								\
+		if (unlikely(cond)) {					\
+			dump_page(&folio->page, "VM_BUG_ON_FOLIO(" __stringify(cond)")");\
+			BUG();						\
+		}							\
+	} while (0)
 #define VM_BUG_ON_VMA(cond, vma)					\
 	do {								\
 		if (unlikely(cond)) {					\
@@ -47,6 +54,17 @@ void dump_mm(const struct mm_struct *mm);
 	}								\
 	unlikely(__ret_warn_once);					\
 })
+#define VM_WARN_ON_ONCE_FOLIO(cond, folio)	({			\
+	static bool __section(".data.once") __warned;			\
+	int __ret_warn_once = !!(cond);					\
+									\
+	if (unlikely(__ret_warn_once && !__warned)) {			\
+		dump_page(&folio->page, "VM_WARN_ON_ONCE_FOLIO(" __stringify(cond)")");\
+		__warned = true;					\
+		WARN_ON(1);						\
+	}								\
+	unlikely(__ret_warn_once);					\
+})
 
 #define VM_WARN_ON(cond) (void)WARN_ON(cond)
 #define VM_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)
@@ -55,11 +73,13 @@ void dump_mm(const struct mm_struct *mm);
 #else
 #define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
 #define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond)
+#define VM_BUG_ON_FOLIO(cond, folio) VM_BUG_ON(cond)
 #define VM_BUG_ON_VMA(cond, vma) VM_BUG_ON(cond)
 #define VM_BUG_ON_MM(cond, mm) VM_BUG_ON(cond)
 #define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN_ON_ONCE_PAGE(cond, page)  BUILD_BUG_ON_INVALID(cond)
+#define VM_WARN_ON_ONCE_FOLIO(cond, folio)  BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond)
 #endif

include/linux/netfs.h

@@ -22,6 +22,7 @@
  * Overload PG_private_2 to give us PG_fscache - this is used to indicate that
  * a page is currently backed by a local disk cache
  */
+#define folio_test_fscache(folio)	folio_test_private_2(folio)
 #define PageFsCache(page)		PagePrivate2((page))
 #define SetPageFsCache(page)		SetPagePrivate2((page))
 #define ClearPageFsCache(page)		ClearPagePrivate2((page))
@@ -29,60 +30,80 @@
 #define TestClearPageFsCache(page)	TestClearPagePrivate2((page))
 
 /**
- * set_page_fscache - Set PG_fscache on a page and take a ref
+ * folio_start_fscache - Start an fscache write on a folio.
- * @page: The page.
+ * @folio: The folio.
  *
- * Set the PG_fscache (PG_private_2) flag on a page and take the reference
+ * Call this function before writing a folio to a local cache.  Starting a
- * needed for the VM to handle its lifetime correctly.  This sets the flag and
+ * second write before the first one finishes is not allowed.
- * takes the reference unconditionally, so care must be taken not to set the
- * flag again if it's already set.
  */
-static inline void set_page_fscache(struct page *page)
+static inline void folio_start_fscache(struct folio *folio)
 {
-	set_page_private_2(page);
+	VM_BUG_ON_FOLIO(folio_test_private_2(folio), folio);
+	folio_get(folio);
+	folio_set_private_2(folio);
 }
 
 /**
- * end_page_fscache - Clear PG_fscache and release any waiters
+ * folio_end_fscache - End an fscache write on a folio.
- * @page: The page
+ * @folio: The folio.
  *
- * Clear the PG_fscache (PG_private_2) bit on a page and wake up any sleepers
+ * Call this function after the folio has been written to the local cache.
- * waiting for this.  The page ref held for PG_private_2 being set is released.
+ * This will wake any sleepers waiting on this folio.
- *
- * This is, for example, used when a netfs page is being written to a local
- * disk cache, thereby allowing writes to the cache for the same page to be
- * serialised.
  */
-static inline void end_page_fscache(struct page *page)
+static inline void folio_end_fscache(struct folio *folio)
 {
-	end_page_private_2(page);
+	folio_end_private_2(folio);
 }
 
 /**
- * wait_on_page_fscache - Wait for PG_fscache to be cleared on a page
+ * folio_wait_fscache - Wait for an fscache write on this folio to end.
- * @page: The page to wait on
+ * @folio: The folio.
  *
- * Wait for PG_fscache (aka PG_private_2) to be cleared on a page.
+ * If this folio is currently being written to a local cache, wait for
+ * the write to finish.  Another write may start after this one finishes,
+ * unless the caller holds the folio lock.
  */
-static inline void wait_on_page_fscache(struct page *page)
+static inline void folio_wait_fscache(struct folio *folio)
 {
-	wait_on_page_private_2(page);
+	folio_wait_private_2(folio);
 }
 
 /**
- * wait_on_page_fscache_killable - Wait for PG_fscache to be cleared on a page
+ * folio_wait_fscache_killable - Wait for an fscache write on this folio to end.
- * @page: The page to wait on
+ * @folio: The folio.
  *
- * Wait for PG_fscache (aka PG_private_2) to be cleared on a page or until a
+ * If this folio is currently being written to a local cache, wait
- * fatal signal is received by the calling task.
+ * for the write to finish or for a fatal signal to be received.
+ * Another write may start after this one finishes, unless the caller
+ * holds the folio lock.
  *
  * Return:
  * - 0 if successful.
  * - -EINTR if a fatal signal was encountered.
  */
+static inline int folio_wait_fscache_killable(struct folio *folio)
+{
+	return folio_wait_private_2_killable(folio);
+}
+
+static inline void set_page_fscache(struct page *page)
+{
+	folio_start_fscache(page_folio(page));
+}
+
+static inline void end_page_fscache(struct page *page)
+{
+	folio_end_private_2(page_folio(page));
+}
+
+static inline void wait_on_page_fscache(struct page *page)
+{
+	folio_wait_private_2(page_folio(page));
+}
+
 static inline int wait_on_page_fscache_killable(struct page *page)
 {
-	return wait_on_page_private_2_killable(page);
+	return folio_wait_private_2_killable(page_folio(page));
 }
 
 enum netfs_read_source {

include/linux/page-flags.h

@@ -143,6 +143,8 @@ enum pageflags {
 #endif
 	__NR_PAGEFLAGS,
 
+	PG_readahead = PG_reclaim,
+
 	/* Filesystems */
 	PG_checked = PG_owner_priv_1,
 
@@ -202,6 +204,34 @@ static inline unsigned long _compound_head(const struct page *page)
 
 #define compound_head(page)	((typeof(page))_compound_head(page))
 
+/**
+ * page_folio - Converts from page to folio.
+ * @p: The page.
+ *
+ * Every page is part of a folio.  This function cannot be called on a
+ * NULL pointer.
+ *
+ * Context: No reference, nor lock is required on @page.  If the caller
+ * does not hold a reference, this call may race with a folio split, so
+ * it should re-check the folio still contains this page after gaining
+ * a reference on the folio.
+ * Return: The folio which contains this page.
+ */
+#define page_folio(p)		(_Generic((p),				\
+	const struct page *:	(const struct folio *)_compound_head(p), \
+	struct page *:		(struct folio *)_compound_head(p)))
+
+/**
+ * folio_page - Return a page from a folio.
+ * @folio: The folio.
+ * @n: The page number to return.
+ *
+ * @n is relative to the start of the folio.  This function does not
+ * check that the page number lies within @folio; the caller is presumed
+ * to have a reference to the page.
+ */
+#define folio_page(folio, n)	nth_page(&(folio)->page, n)
+
 static __always_inline int PageTail(struct page *page)
 {
 	return READ_ONCE(page->compound_head) & 1;
@@ -226,6 +256,15 @@ static inline void page_init_poison(struct page *page, size_t size)
 }
 #endif
 
+static unsigned long *folio_flags(struct folio *folio, unsigned n)
+{
+	struct page *page = &folio->page;
+
+	VM_BUG_ON_PGFLAGS(PageTail(page), page);
+	VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
+	return &page[n].flags;
+}
+
 /*
  * Page flags policies wrt compound pages
  *
@@ -270,36 +309,64 @@ static inline void page_init_poison(struct page *page, size_t size)
 		VM_BUG_ON_PGFLAGS(!PageHead(page), page);		\
 		PF_POISONED_CHECK(&page[1]); })
 
+/* Which page is the flag stored in */
+#define FOLIO_PF_ANY		0
+#define FOLIO_PF_HEAD		0
+#define FOLIO_PF_ONLY_HEAD	0
+#define FOLIO_PF_NO_TAIL	0
+#define FOLIO_PF_NO_COMPOUND	0
+#define FOLIO_PF_SECOND		1
+
 /*
  * Macros to create function definitions for page flags
  */
 #define TESTPAGEFLAG(uname, lname, policy)				\
+static __always_inline bool folio_test_##lname(struct folio *folio)	\
+{ return test_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); }	\
 static __always_inline int Page##uname(struct page *page)		\
-	{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
+{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
 
 #define SETPAGEFLAG(uname, lname, policy)				\
+static __always_inline							\
+void folio_set_##lname(struct folio *folio)				\
+{ set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); }		\
 static __always_inline void SetPage##uname(struct page *page)		\
-	{ set_bit(PG_##lname, &policy(page, 1)->flags); }
+{ set_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define CLEARPAGEFLAG(uname, lname, policy)				\
+static __always_inline							\
+void folio_clear_##lname(struct folio *folio)				\
+{ clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); }		\
 static __always_inline void ClearPage##uname(struct page *page)		\
-	{ clear_bit(PG_##lname, &policy(page, 1)->flags); }
+{ clear_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define __SETPAGEFLAG(uname, lname, policy)				\
+static __always_inline							\
+void __folio_set_##lname(struct folio *folio)				\
+{ __set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); }		\
 static __always_inline void __SetPage##uname(struct page *page)		\
-	{ __set_bit(PG_##lname, &policy(page, 1)->flags); }
+{ __set_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define __CLEARPAGEFLAG(uname, lname, policy)				\
+static __always_inline							\
+void __folio_clear_##lname(struct folio *folio)				\
+{ __clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); }	\
 static __always_inline void __ClearPage##uname(struct page *page)	\
-	{ __clear_bit(PG_##lname, &policy(page, 1)->flags); }
+{ __clear_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define TESTSETFLAG(uname, lname, policy)				\
+static __always_inline							\
+bool folio_test_set_##lname(struct folio *folio)			\
+{ return test_and_set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
 static __always_inline int TestSetPage##uname(struct page *page)	\
-	{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
+{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define TESTCLEARFLAG(uname, lname, policy)				\
+static __always_inline							\
+bool folio_test_clear_##lname(struct folio *folio)			\
+{ return test_and_clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
 static __always_inline int TestClearPage##uname(struct page *page)	\
-	{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
+{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
 
 #define PAGEFLAG(uname, lname, policy)					\
 	TESTPAGEFLAG(uname, lname, policy)				\
@@ -315,29 +382,37 @@ static __always_inline int TestClearPage##uname(struct page *page)	\
 	TESTSETFLAG(uname, lname, policy)				\
 	TESTCLEARFLAG(uname, lname, policy)
 
-#define TESTPAGEFLAG_FALSE(uname)					\
+#define TESTPAGEFLAG_FALSE(uname, lname)				\
+static inline bool folio_test_##lname(const struct folio *folio) { return 0; } \
 static inline int Page##uname(const struct page *page) { return 0; }
 
-#define SETPAGEFLAG_NOOP(uname)						\
+#define SETPAGEFLAG_NOOP(uname, lname)					\
+static inline void folio_set_##lname(struct folio *folio) { }		\
 static inline void SetPage##uname(struct page *page) {  }
 
-#define CLEARPAGEFLAG_NOOP(uname)					\
+#define CLEARPAGEFLAG_NOOP(uname, lname)				\
+static inline void folio_clear_##lname(struct folio *folio) { }		\
 static inline void ClearPage##uname(struct page *page) {  }
 
-#define __CLEARPAGEFLAG_NOOP(uname)					\
+#define __CLEARPAGEFLAG_NOOP(uname, lname)				\
+static inline void __folio_clear_##lname(struct folio *folio) { }	\
 static inline void __ClearPage##uname(struct page *page) {  }
 
-#define TESTSETFLAG_FALSE(uname)					\
+#define TESTSETFLAG_FALSE(uname, lname)					\
+static inline bool folio_test_set_##lname(struct folio *folio)		\
+{ return 0; }								\
 static inline int TestSetPage##uname(struct page *page) { return 0; }
 
-#define TESTCLEARFLAG_FALSE(uname)					\
+#define TESTCLEARFLAG_FALSE(uname, lname)				\
+static inline bool folio_test_clear_##lname(struct folio *folio)	\
+{ return 0; }								\
 static inline int TestClearPage##uname(struct page *page) { return 0; }
 
-#define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname)			\
+#define PAGEFLAG_FALSE(uname, lname) TESTPAGEFLAG_FALSE(uname, lname)	\
-	SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname)
+	SETPAGEFLAG_NOOP(uname, lname) CLEARPAGEFLAG_NOOP(uname, lname)
 
-#define TESTSCFLAG_FALSE(uname)						\
+#define TESTSCFLAG_FALSE(uname, lname)					\
-	TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname)
+	TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname)
 
 __PAGEFLAG(Locked, locked, PF_NO_TAIL)
 PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD)
@@ -393,8 +468,8 @@ PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL)
 /* PG_readahead is only used for reads; PG_reclaim is only for writes */
 PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL)
 	TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL)
-PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND)
+PAGEFLAG(Readahead, readahead, PF_NO_COMPOUND)
-	TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND)
+	TESTCLEARFLAG(Readahead, readahead, PF_NO_COMPOUND)
 
 #ifdef CONFIG_HIGHMEM
 /*
@@ -403,22 +478,25 @@ PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND)
  */
 #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p))
 #else
-PAGEFLAG_FALSE(HighMem)
+PAGEFLAG_FALSE(HighMem, highmem)
 #endif
 
 #ifdef CONFIG_SWAP
-static __always_inline int PageSwapCache(struct page *page)
+static __always_inline bool folio_test_swapcache(struct folio *folio)
 {
-#ifdef CONFIG_THP_SWAP
+	return folio_test_swapbacked(folio) &&
-	page = compound_head(page);
+			test_bit(PG_swapcache, folio_flags(folio, 0));
-#endif
-	return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags);
-
 }
+
+static __always_inline bool PageSwapCache(struct page *page)
+{
+	return folio_test_swapcache(page_folio(page));
+}
+
 SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
 CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
 #else
-PAGEFLAG_FALSE(SwapCache)
+PAGEFLAG_FALSE(SwapCache, swapcache)
 #endif
 
 PAGEFLAG(Unevictable, unevictable, PF_HEAD)
@@ -430,14 +508,14 @@ PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)
 	__CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)
 	TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL)
 #else
-PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked)
+PAGEFLAG_FALSE(Mlocked, mlocked) __CLEARPAGEFLAG_NOOP(Mlocked, mlocked)
-	TESTSCFLAG_FALSE(Mlocked)
+	TESTSCFLAG_FALSE(Mlocked, mlocked)
 #endif
 
 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
 PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND)
 #else
-PAGEFLAG_FALSE(Uncached)
+PAGEFLAG_FALSE(Uncached, uncached)
 #endif
 
 #ifdef CONFIG_MEMORY_FAILURE
@@ -446,7 +524,7 @@ TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
 #define __PG_HWPOISON (1UL << PG_hwpoison)
 extern bool take_page_off_buddy(struct page *page);
 #else
-PAGEFLAG_FALSE(HWPoison)
+PAGEFLAG_FALSE(HWPoison, hwpoison)
 #define __PG_HWPOISON 0
 #endif
 
@@ -460,7 +538,7 @@ PAGEFLAG(Idle, idle, PF_ANY)
 #ifdef CONFIG_KASAN_HW_TAGS
 PAGEFLAG(SkipKASanPoison, skip_kasan_poison, PF_HEAD)
 #else
-PAGEFLAG_FALSE(SkipKASanPoison)
+PAGEFLAG_FALSE(SkipKASanPoison, skip_kasan_poison)
 #endif
 
 /*
@@ -498,10 +576,14 @@ static __always_inline int PageMappingFlags(struct page *page)
 	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0;
 }
 
-static __always_inline int PageAnon(struct page *page)
+static __always_inline bool folio_test_anon(struct folio *folio)
 {
-	page = compound_head(page);
+	return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0;
-	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
+}
+
+static __always_inline bool PageAnon(struct page *page)
+{
+	return folio_test_anon(page_folio(page));
 }
 
 static __always_inline int __PageMovable(struct page *page)
@@ -517,30 +599,32 @@ static __always_inline int __PageMovable(struct page *page)
  * is found in VM_MERGEABLE vmas.  It's a PageAnon page, pointing not to any
  * anon_vma, but to that page's node of the stable tree.
  */
-static __always_inline int PageKsm(struct page *page)
+static __always_inline bool folio_test_ksm(struct folio *folio)
 {
-	page = compound_head(page);
+	return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) ==
-	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
 				PAGE_MAPPING_KSM;
 }
+
+static __always_inline bool PageKsm(struct page *page)
+{
+	return folio_test_ksm(page_folio(page));
+}
 #else
-TESTPAGEFLAG_FALSE(Ksm)
+TESTPAGEFLAG_FALSE(Ksm, ksm)
 #endif
 
 u64 stable_page_flags(struct page *page);
 
-static inline int PageUptodate(struct page *page)
+static inline bool folio_test_uptodate(struct folio *folio)
 {
-	int ret;
+	bool ret = test_bit(PG_uptodate, folio_flags(folio, 0));
-	page = compound_head(page);
-	ret = test_bit(PG_uptodate, &(page)->flags);
 	/*
-	 * Must ensure that the data we read out of the page is loaded
+	 * Must ensure that the data we read out of the folio is loaded
-	 * _after_ we've loaded page->flags to check for PageUptodate.
+	 * _after_ we've loaded folio->flags to check the uptodate bit.
-	 * We can skip the barrier if the page is not uptodate, because
+	 * We can skip the barrier if the folio is not uptodate, because
 	 * we wouldn't be reading anything from it.
 	 *
-	 * See SetPageUptodate() for the other side of the story.
+	 * See folio_mark_uptodate() for the other side of the story.
 	 */
 	if (ret)
 		smp_rmb();
@@ -548,47 +632,71 @@ static inline int PageUptodate(struct page *page)
 	return ret;
 }
 
+static inline int PageUptodate(struct page *page)
+{
+	return folio_test_uptodate(page_folio(page));
+}
+
+static __always_inline void __folio_mark_uptodate(struct folio *folio)
+{
+	smp_wmb();
+	__set_bit(PG_uptodate, folio_flags(folio, 0));
+}
+
+static __always_inline void folio_mark_uptodate(struct folio *folio)
+{
+	/*
+	 * Memory barrier must be issued before setting the PG_uptodate bit,
+	 * so that all previous stores issued in order to bring the folio
+	 * uptodate are actually visible before folio_test_uptodate becomes true.
+	 */
+	smp_wmb();
+	set_bit(PG_uptodate, folio_flags(folio, 0));
+}
+
 static __always_inline void __SetPageUptodate(struct page *page)
 {
-	VM_BUG_ON_PAGE(PageTail(page), page);
+	__folio_mark_uptodate((struct folio *)page);
-	smp_wmb();
-	__set_bit(PG_uptodate, &page->flags);
 }
 
 static __always_inline void SetPageUptodate(struct page *page)
 {
-	VM_BUG_ON_PAGE(PageTail(page), page);
+	folio_mark_uptodate((struct folio *)page);
-	/*
-	 * Memory barrier must be issued before setting the PG_uptodate bit,
-	 * so that all previous stores issued in order to bring the page
-	 * uptodate are actually visible before PageUptodate becomes true.
-	 */
-	smp_wmb();
-	set_bit(PG_uptodate, &page->flags);
 }
 
 CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL)
 
-int test_clear_page_writeback(struct page *page);
+bool __folio_start_writeback(struct folio *folio, bool keep_write);
-int __test_set_page_writeback(struct page *page, bool keep_write);
+bool set_page_writeback(struct page *page);
 
-#define test_set_page_writeback(page)			\
+#define folio_start_writeback(folio)			\
-	__test_set_page_writeback(page, false)
+	__folio_start_writeback(folio, false)
-#define test_set_page_writeback_keepwrite(page)	\
+#define folio_start_writeback_keepwrite(folio)	\
-	__test_set_page_writeback(page, true)
+	__folio_start_writeback(folio, true)
-
-static inline void set_page_writeback(struct page *page)
-{
-	test_set_page_writeback(page);
-}
 
 static inline void set_page_writeback_keepwrite(struct page *page)
 {
-	test_set_page_writeback_keepwrite(page);
+	folio_start_writeback_keepwrite(page_folio(page));
+}
+
+static inline bool test_set_page_writeback(struct page *page)
+{
+	return set_page_writeback(page);
 }
 
 __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY)
 
+/* Whether there are one or multiple pages in a folio */
+static inline bool folio_test_single(struct folio *folio)
+{
+	return !folio_test_head(folio);
+}
+
+static inline bool folio_test_multi(struct folio *folio)
+{
+	return folio_test_head(folio);
+}
+
 static __always_inline void set_compound_head(struct page *page, struct page *head)
 {
 	WRITE_ONCE(page->compound_head, (unsigned long)head + 1);
@@ -612,12 +720,15 @@ static inline void ClearPageCompound(struct page *page)
 #ifdef CONFIG_HUGETLB_PAGE
 int PageHuge(struct page *page);
 int PageHeadHuge(struct page *page);
+static inline bool folio_test_hugetlb(struct folio *folio)
+{
+	return PageHeadHuge(&folio->page);
+}
 #else
-TESTPAGEFLAG_FALSE(Huge)
+TESTPAGEFLAG_FALSE(Huge, hugetlb)
-TESTPAGEFLAG_FALSE(HeadHuge)
+TESTPAGEFLAG_FALSE(HeadHuge, headhuge)
 #endif
 
-
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /*
  * PageHuge() only returns true for hugetlbfs pages, but not for
@@ -633,6 +744,11 @@ static inline int PageTransHuge(struct page *page)
 	return PageHead(page);
 }
 
+static inline bool folio_test_transhuge(struct folio *folio)
+{
+	return folio_test_head(folio);
+}
+
 /*
  * PageTransCompound returns true for both transparent huge pages
  * and hugetlbfs pages, so it should only be called when it's known
@@ -669,12 +785,12 @@ static inline int PageTransTail(struct page *page)
 PAGEFLAG(DoubleMap, double_map, PF_SECOND)
 	TESTSCFLAG(DoubleMap, double_map, PF_SECOND)
 #else
-TESTPAGEFLAG_FALSE(TransHuge)
+TESTPAGEFLAG_FALSE(TransHuge, transhuge)
-TESTPAGEFLAG_FALSE(TransCompound)
+TESTPAGEFLAG_FALSE(TransCompound, transcompound)
-TESTPAGEFLAG_FALSE(TransCompoundMap)
+TESTPAGEFLAG_FALSE(TransCompoundMap, transcompoundmap)
-TESTPAGEFLAG_FALSE(TransTail)
+TESTPAGEFLAG_FALSE(TransTail, transtail)
-PAGEFLAG_FALSE(DoubleMap)
+PAGEFLAG_FALSE(DoubleMap, double_map)
-	TESTSCFLAG_FALSE(DoubleMap)
+	TESTSCFLAG_FALSE(DoubleMap, double_map)
 #endif
 
 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
@@ -872,6 +988,11 @@ static inline int page_has_private(struct page *page)
 	return !!(page->flags & PAGE_FLAGS_PRIVATE);
 }
 
+static inline bool folio_has_private(struct folio *folio)
+{
+	return page_has_private(&folio->page);
+}
+
 #undef PF_ANY
 #undef PF_HEAD
 #undef PF_ONLY_HEAD

include/linux/page_idle.h

@@ -8,46 +8,16 @@
 
 #ifdef CONFIG_PAGE_IDLE_FLAG
 
-#ifdef CONFIG_64BIT
+#ifndef CONFIG_64BIT
-static inline bool page_is_young(struct page *page)
-{
-	return PageYoung(page);
-}
-
-static inline void set_page_young(struct page *page)
-{
-	SetPageYoung(page);
-}
-
-static inline bool test_and_clear_page_young(struct page *page)
-{
-	return TestClearPageYoung(page);
-}
-
-static inline bool page_is_idle(struct page *page)
-{
-	return PageIdle(page);
-}
-
-static inline void set_page_idle(struct page *page)
-{
-	SetPageIdle(page);
-}
-
-static inline void clear_page_idle(struct page *page)
-{
-	ClearPageIdle(page);
-}
-#else /* !CONFIG_64BIT */
 /*
  * If there is not enough space to store Idle and Young bits in page flags, use
  * page ext flags instead.
  */
 extern struct page_ext_operations page_idle_ops;
 
-static inline bool page_is_young(struct page *page)
+static inline bool folio_test_young(struct folio *folio)
 {
-	struct page_ext *page_ext = lookup_page_ext(page);
+	struct page_ext *page_ext = lookup_page_ext(&folio->page);
 
 	if (unlikely(!page_ext))
 		return false;
@@ -55,9 +25,9 @@ static inline bool page_is_young(struct page *page)
 	return test_bit(PAGE_EXT_YOUNG, &page_ext->flags);
 }
 
-static inline void set_page_young(struct page *page)
+static inline void folio_set_young(struct folio *folio)
 {
-	struct page_ext *page_ext = lookup_page_ext(page);
+	struct page_ext *page_ext = lookup_page_ext(&folio->page);
 
 	if (unlikely(!page_ext))
 		return;
@@ -65,9 +35,9 @@ static inline void set_page_young(struct page *page)
 	set_bit(PAGE_EXT_YOUNG, &page_ext->flags);
 }
 
-static inline bool test_and_clear_page_young(struct page *page)
+static inline bool folio_test_clear_young(struct folio *folio)
 {
-	struct page_ext *page_ext = lookup_page_ext(page);
+	struct page_ext *page_ext = lookup_page_ext(&folio->page);
 
 	if (unlikely(!page_ext))
 		return false;
@@ -75,9 +45,9 @@ static inline bool test_and_clear_page_young(struct page *page)
 	return test_and_clear_bit(PAGE_EXT_YOUNG, &page_ext->flags);
 }
 
-static inline bool page_is_idle(struct page *page)
+static inline bool folio_test_idle(struct folio *folio)
 {
-	struct page_ext *page_ext = lookup_page_ext(page);
+	struct page_ext *page_ext = lookup_page_ext(&folio->page);
 
 	if (unlikely(!page_ext))
 		return false;
@@ -85,9 +55,9 @@ static inline bool page_is_idle(struct page *page)
 	return test_bit(PAGE_EXT_IDLE, &page_ext->flags);
 }
 
-static inline void set_page_idle(struct page *page)
+static inline void folio_set_idle(struct folio *folio)
 {
-	struct page_ext *page_ext = lookup_page_ext(page);
+	struct page_ext *page_ext = lookup_page_ext(&folio->page);
 
 	if (unlikely(!page_ext))
 		return;
@@ -95,46 +65,75 @@ static inline void set_page_idle(struct page *page)
 	set_bit(PAGE_EXT_IDLE, &page_ext->flags);
 }
 
-static inline void clear_page_idle(struct page *page)
+static inline void folio_clear_idle(struct folio *folio)
 {
-	struct page_ext *page_ext = lookup_page_ext(page);
+	struct page_ext *page_ext = lookup_page_ext(&folio->page);
 
 	if (unlikely(!page_ext))
 		return;
 
 	clear_bit(PAGE_EXT_IDLE, &page_ext->flags);
 }
-#endif /* CONFIG_64BIT */
+#endif /* !CONFIG_64BIT */
 
 #else /* !CONFIG_PAGE_IDLE_FLAG */
 
-static inline bool page_is_young(struct page *page)
+static inline bool folio_test_young(struct folio *folio)
 {
 	return false;
 }
 
-static inline void set_page_young(struct page *page)
+static inline void folio_set_young(struct folio *folio)
 {
 }
 
-static inline bool test_and_clear_page_young(struct page *page)
+static inline bool folio_test_clear_young(struct folio *folio)
 {
 	return false;
 }
 
-static inline bool page_is_idle(struct page *page)
+static inline bool folio_test_idle(struct folio *folio)
 {
 	return false;
 }
 
-static inline void set_page_idle(struct page *page)
+static inline void folio_set_idle(struct folio *folio)
 {
 }
 
-static inline void clear_page_idle(struct page *page)
+static inline void folio_clear_idle(struct folio *folio)
 {
 }
 
 #endif /* CONFIG_PAGE_IDLE_FLAG */
 
+static inline bool page_is_young(struct page *page)
+{
+	return folio_test_young(page_folio(page));
+}
+
+static inline void set_page_young(struct page *page)
+{
+	folio_set_young(page_folio(page));
+}
+
+static inline bool test_and_clear_page_young(struct page *page)
+{
+	return folio_test_clear_young(page_folio(page));
+}
+
+static inline bool page_is_idle(struct page *page)
+{
+	return folio_test_idle(page_folio(page));
+}
+
+static inline void set_page_idle(struct page *page)
+{
+	folio_set_idle(page_folio(page));
+}
+
+static inline void clear_page_idle(struct page *page)
+{
+	folio_clear_idle(page_folio(page));
+}
 #endif /* _LINUX_MM_PAGE_IDLE_H */

include/linux/page_owner.h

@@ -12,7 +12,7 @@ extern void __reset_page_owner(struct page *page, unsigned int order);
 extern void __set_page_owner(struct page *page,
 			unsigned int order, gfp_t gfp_mask);
 extern void __split_page_owner(struct page *page, unsigned int nr);
-extern void __copy_page_owner(struct page *oldpage, struct page *newpage);
+extern void __folio_copy_owner(struct folio *newfolio, struct folio *old);
 extern void __set_page_owner_migrate_reason(struct page *page, int reason);
 extern void __dump_page_owner(const struct page *page);
 extern void pagetypeinfo_showmixedcount_print(struct seq_file *m,
@@ -36,10 +36,10 @@ static inline void split_page_owner(struct page *page, unsigned int nr)
 	if (static_branch_unlikely(&page_owner_inited))
 		__split_page_owner(page, nr);
 }
-static inline void copy_page_owner(struct page *oldpage, struct page *newpage)
+static inline void folio_copy_owner(struct folio *newfolio, struct folio *old)
 {
 	if (static_branch_unlikely(&page_owner_inited))
-		__copy_page_owner(oldpage, newpage);
+		__folio_copy_owner(newfolio, old);
 }
 static inline void set_page_owner_migrate_reason(struct page *page, int reason)
 {
@@ -63,7 +63,7 @@ static inline void split_page_owner(struct page *page,
 			unsigned int order)
 {
 }
-static inline void copy_page_owner(struct page *oldpage, struct page *newpage)
+static inline void folio_copy_owner(struct folio *newfolio, struct folio *folio)
 {
 }
 static inline void set_page_owner_migrate_reason(struct page *page, int reason)

include/linux/page_ref.h

@@ -67,9 +67,31 @@ static inline int page_ref_count(const struct page *page)
 	return atomic_read(&page->_refcount);
 }
 
+/**
+ * folio_ref_count - The reference count on this folio.
+ * @folio: The folio.
+ *
+ * The refcount is usually incremented by calls to folio_get() and
+ * decremented by calls to folio_put().  Some typical users of the
+ * folio refcount:
+ *
+ * - Each reference from a page table
+ * - The page cache
+ * - Filesystem private data
+ * - The LRU list
+ * - Pipes
+ * - Direct IO which references this page in the process address space
+ *
+ * Return: The number of references to this folio.
+ */
+static inline int folio_ref_count(const struct folio *folio)
+{
+	return page_ref_count(&folio->page);
+}
+
 static inline int page_count(const struct page *page)
 {
-	return atomic_read(&compound_head(page)->_refcount);
+	return folio_ref_count(page_folio(page));
 }
 
 static inline void set_page_count(struct page *page, int v)
@@ -79,6 +101,11 @@ static inline void set_page_count(struct page *page, int v)
 		__page_ref_set(page, v);
 }
 
+static inline void folio_set_count(struct folio *folio, int v)
+{
+	set_page_count(&folio->page, v);
+}
+
 /*
  * Setup the page count before being freed into the page allocator for
  * the first time (boot or memory hotplug)
@@ -95,6 +122,11 @@ static inline void page_ref_add(struct page *page, int nr)
 		__page_ref_mod(page, nr);
 }
 
+static inline void folio_ref_add(struct folio *folio, int nr)
+{
+	page_ref_add(&folio->page, nr);
+}
+
 static inline void page_ref_sub(struct page *page, int nr)
 {
 	atomic_sub(nr, &page->_refcount);
@@ -102,6 +134,11 @@ static inline void page_ref_sub(struct page *page, int nr)
 		__page_ref_mod(page, -nr);
 }
 
+static inline void folio_ref_sub(struct folio *folio, int nr)
+{
+	page_ref_sub(&folio->page, nr);
+}
+
 static inline int page_ref_sub_return(struct page *page, int nr)
 {
 	int ret = atomic_sub_return(nr, &page->_refcount);
@@ -111,6 +148,11 @@ static inline int page_ref_sub_return(struct page *page, int nr)
 	return ret;
 }
 
+static inline int folio_ref_sub_return(struct folio *folio, int nr)
+{
+	return page_ref_sub_return(&folio->page, nr);
+}
+
 static inline void page_ref_inc(struct page *page)
 {
 	atomic_inc(&page->_refcount);
@@ -118,6 +160,11 @@ static inline void page_ref_inc(struct page *page)
 		__page_ref_mod(page, 1);
 }
 
+static inline void folio_ref_inc(struct folio *folio)
+{
+	page_ref_inc(&folio->page);
+}
+
 static inline void page_ref_dec(struct page *page)
 {
 	atomic_dec(&page->_refcount);
@@ -125,6 +172,11 @@ static inline void page_ref_dec(struct page *page)
 		__page_ref_mod(page, -1);
 }
 
+static inline void folio_ref_dec(struct folio *folio)
+{
+	page_ref_dec(&folio->page);
+}
+
 static inline int page_ref_sub_and_test(struct page *page, int nr)
 {
 	int ret = atomic_sub_and_test(nr, &page->_refcount);
@@ -134,6 +186,11 @@ static inline int page_ref_sub_and_test(struct page *page, int nr)
 	return ret;
 }
 
+static inline int folio_ref_sub_and_test(struct folio *folio, int nr)
+{
+	return page_ref_sub_and_test(&folio->page, nr);
+}
+
 static inline int page_ref_inc_return(struct page *page)
 {
 	int ret = atomic_inc_return(&page->_refcount);
@@ -143,6 +200,11 @@ static inline int page_ref_inc_return(struct page *page)
 	return ret;
 }
 
+static inline int folio_ref_inc_return(struct folio *folio)
+{
+	return page_ref_inc_return(&folio->page);
+}
+
 static inline int page_ref_dec_and_test(struct page *page)
 {
 	int ret = atomic_dec_and_test(&page->_refcount);
@@ -152,6 +214,11 @@ static inline int page_ref_dec_and_test(struct page *page)
 	return ret;
 }
 
+static inline int folio_ref_dec_and_test(struct folio *folio)
+{
+	return page_ref_dec_and_test(&folio->page);
+}
+
 static inline int page_ref_dec_return(struct page *page)
 {
 	int ret = atomic_dec_return(&page->_refcount);
@@ -161,15 +228,91 @@ static inline int page_ref_dec_return(struct page *page)
 	return ret;
 }
 
-static inline int page_ref_add_unless(struct page *page, int nr, int u)
+static inline int folio_ref_dec_return(struct folio *folio)
 {
-	int ret = atomic_add_unless(&page->_refcount, nr, u);
+	return page_ref_dec_return(&folio->page);
+}
+
+static inline bool page_ref_add_unless(struct page *page, int nr, int u)
+{
+	bool ret = atomic_add_unless(&page->_refcount, nr, u);
 
 	if (page_ref_tracepoint_active(page_ref_mod_unless))
 		__page_ref_mod_unless(page, nr, ret);
 	return ret;
 }
 
+static inline bool folio_ref_add_unless(struct folio *folio, int nr, int u)
+{
+	return page_ref_add_unless(&folio->page, nr, u);
+}
+
+/**
+ * folio_try_get - Attempt to increase the refcount on a folio.
+ * @folio: The folio.
+ *
+ * If you do not already have a reference to a folio, you can attempt to
+ * get one using this function.  It may fail if, for example, the folio
+ * has been freed since you found a pointer to it, or it is frozen for
+ * the purposes of splitting or migration.
+ *
+ * Return: True if the reference count was successfully incremented.
+ */
+static inline bool folio_try_get(struct folio *folio)
+{
+	return folio_ref_add_unless(folio, 1, 0);
+}
+
+static inline bool folio_ref_try_add_rcu(struct folio *folio, int count)
+{
+#ifdef CONFIG_TINY_RCU
+	/*
+	 * The caller guarantees the folio will not be freed from interrupt
+	 * context, so (on !SMP) we only need preemption to be disabled
+	 * and TINY_RCU does that for us.
+	 */
+# ifdef CONFIG_PREEMPT_COUNT
+	VM_BUG_ON(!in_atomic() && !irqs_disabled());
+# endif
+	VM_BUG_ON_FOLIO(folio_ref_count(folio) == 0, folio);
+	folio_ref_add(folio, count);
+#else
+	if (unlikely(!folio_ref_add_unless(folio, count, 0))) {
+		/* Either the folio has been freed, or will be freed. */
+		return false;
+	}
+#endif
+	return true;
+}
+
+/**
+ * folio_try_get_rcu - Attempt to increase the refcount on a folio.
+ * @folio: The folio.
+ *
+ * This is a version of folio_try_get() optimised for non-SMP kernels.
+ * If you are still holding the rcu_read_lock() after looking up the
+ * page and know that the page cannot have its refcount decreased to
+ * zero in interrupt context, you can use this instead of folio_try_get().
+ *
+ * Example users include get_user_pages_fast() (as pages are not unmapped
+ * from interrupt context) and the page cache lookups (as pages are not
+ * truncated from interrupt context).  We also know that pages are not
+ * frozen in interrupt context for the purposes of splitting or migration.
+ *
+ * You can also use this function if you're holding a lock that prevents
+ * pages being frozen & removed; eg the i_pages lock for the page cache
+ * or the mmap_sem or page table lock for page tables.  In this case,
+ * it will always succeed, and you could have used a plain folio_get(),
+ * but it's sometimes more convenient to have a common function called
+ * from both locked and RCU-protected contexts.
+ *
+ * Return: True if the reference count was successfully incremented.
+ */
+static inline bool folio_try_get_rcu(struct folio *folio)
+{
+	return folio_ref_try_add_rcu(folio, 1);
+}
+
 static inline int page_ref_freeze(struct page *page, int count)
 {
 	int ret = likely(atomic_cmpxchg(&page->_refcount, count, 0) == count);
@@ -179,6 +322,11 @@ static inline int page_ref_freeze(struct page *page, int count)
 	return ret;
 }
 
+static inline int folio_ref_freeze(struct folio *folio, int count)
+{
+	return page_ref_freeze(&folio->page, count);
+}
+
 static inline void page_ref_unfreeze(struct page *page, int count)
 {
 	VM_BUG_ON_PAGE(page_count(page) != 0, page);
@@ -189,4 +337,8 @@ static inline void page_ref_unfreeze(struct page *page, int count)
 		__page_ref_unfreeze(page, count);
 }
 
+static inline void folio_ref_unfreeze(struct folio *folio, int count)
+{
+	page_ref_unfreeze(&folio->page, count);
+}
 #endif

include/linux/pagemap.h

@@ -162,149 +162,119 @@ static inline void filemap_nr_thps_dec(struct address_space *mapping)
 
 void release_pages(struct page **pages, int nr);
 
+struct address_space *page_mapping(struct page *);
+struct address_space *folio_mapping(struct folio *);
+struct address_space *swapcache_mapping(struct folio *);
+
+/**
+ * folio_file_mapping - Find the mapping this folio belongs to.
+ * @folio: The folio.
+ *
+ * For folios which are in the page cache, return the mapping that this
+ * page belongs to.  Folios in the swap cache return the mapping of the
+ * swap file or swap device where the data is stored.  This is different
+ * from the mapping returned by folio_mapping().  The only reason to
+ * use it is if, like NFS, you return 0 from ->activate_swapfile.
+ *
+ * Do not call this for folios which aren't in the page cache or swap cache.
+ */
+static inline struct address_space *folio_file_mapping(struct folio *folio)
+{
+	if (unlikely(folio_test_swapcache(folio)))
+		return swapcache_mapping(folio);
+
+	return folio->mapping;
+}
+
+static inline struct address_space *page_file_mapping(struct page *page)
+{
+	return folio_file_mapping(page_folio(page));
+}
+
 /*
  * For file cache pages, return the address_space, otherwise return NULL
  */
 static inline struct address_space *page_mapping_file(struct page *page)
 {
-	if (unlikely(PageSwapCache(page)))
+	struct folio *folio = page_folio(page);
+
+	if (unlikely(folio_test_swapcache(folio)))
 		return NULL;
-	return page_mapping(page);
+	return folio_mapping(folio);
 }
 
-/*
+static inline bool page_cache_add_speculative(struct page *page, int count)
- * speculatively take a reference to a page.
- * If the page is free (_refcount == 0), then _refcount is untouched, and 0
- * is returned. Otherwise, _refcount is incremented by 1 and 1 is returned.
- *
- * This function must be called inside the same rcu_read_lock() section as has
- * been used to lookup the page in the pagecache radix-tree (or page table):
- * this allows allocators to use a synchronize_rcu() to stabilize _refcount.
- *
- * Unless an RCU grace period has passed, the count of all pages coming out
- * of the allocator must be considered unstable. page_count may return higher
- * than expected, and put_page must be able to do the right thing when the
- * page has been finished with, no matter what it is subsequently allocated
- * for (because put_page is what is used here to drop an invalid speculative
- * reference).
- *
- * This is the interesting part of the lockless pagecache (and lockless
- * get_user_pages) locking protocol, where the lookup-side (eg. find_get_page)
- * has the following pattern:
- * 1. find page in radix tree
- * 2. conditionally increment refcount
- * 3. check the page is still in pagecache (if no, goto 1)
- *
- * Remove-side that cares about stability of _refcount (eg. reclaim) has the
- * following (with the i_pages lock held):
- * A. atomically check refcount is correct and set it to 0 (atomic_cmpxchg)
- * B. remove page from pagecache
- * C. free the page
- *
- * There are 2 critical interleavings that matter:
- * - 2 runs before A: in this case, A sees elevated refcount and bails out
- * - A runs before 2: in this case, 2 sees zero refcount and retries;
- *   subsequently, B will complete and 1 will find no page, causing the
- *   lookup to return NULL.
- *
- * It is possible that between 1 and 2, the page is removed then the exact same
- * page is inserted into the same position in pagecache. That's OK: the
- * old find_get_page using a lock could equally have run before or after
- * such a re-insertion, depending on order that locks are granted.
- *
- * Lookups racing against pagecache insertion isn't a big problem: either 1
- * will find the page or it will not. Likewise, the old find_get_page could run
- * either before the insertion or afterwards, depending on timing.
- */
-static inline int __page_cache_add_speculative(struct page *page, int count)
 {
-#ifdef CONFIG_TINY_RCU
-# ifdef CONFIG_PREEMPT_COUNT
-	VM_BUG_ON(!in_atomic() && !irqs_disabled());
-# endif
-	/*
-	 * Preempt must be disabled here - we rely on rcu_read_lock doing
-	 * this for us.
-	 *
-	 * Pagecache won't be truncated from interrupt context, so if we have
-	 * found a page in the radix tree here, we have pinned its refcount by
-	 * disabling preempt, and hence no need for the "speculative get" that
-	 * SMP requires.
-	 */
-	VM_BUG_ON_PAGE(page_count(page) == 0, page);
-	page_ref_add(page, count);
-
-#else
-	if (unlikely(!page_ref_add_unless(page, count, 0))) {
-		/*
-		 * Either the page has been freed, or will be freed.
-		 * In either case, retry here and the caller should
-		 * do the right thing (see comments above).
-		 */
-		return 0;
-	}
-#endif
 	VM_BUG_ON_PAGE(PageTail(page), page);
-
+	return folio_ref_try_add_rcu((struct folio *)page, count);
-	return 1;
 }
 
-static inline int page_cache_get_speculative(struct page *page)
+static inline bool page_cache_get_speculative(struct page *page)
 {
-	return __page_cache_add_speculative(page, 1);
+	return page_cache_add_speculative(page, 1);
-}
-
-static inline int page_cache_add_speculative(struct page *page, int count)
-{
-	return __page_cache_add_speculative(page, count);
 }
 
 /**
- * attach_page_private - Attach private data to a page.
+ * folio_attach_private - Attach private data to a folio.
- * @page: Page to attach data to.
+ * @folio: Folio to attach data to.
- * @data: Data to attach to page.
+ * @data: Data to attach to folio.
  *
- * Attaching private data to a page increments the page's reference count.
+ * Attaching private data to a folio increments the page's reference count.
- * The data must be detached before the page will be freed.
+ * The data must be detached before the folio will be freed.
  */
-static inline void attach_page_private(struct page *page, void *data)
+static inline void folio_attach_private(struct folio *folio, void *data)
 {
-	get_page(page);
+	folio_get(folio);
-	set_page_private(page, (unsigned long)data);
+	folio->private = data;
-	SetPagePrivate(page);
+	folio_set_private(folio);
 }
 
 /**
- * detach_page_private - Detach private data from a page.
+ * folio_detach_private - Detach private data from a folio.
- * @page: Page to detach data from.
+ * @folio: Folio to detach data from.
  *
- * Removes the data that was previously attached to the page and decrements
+ * Removes the data that was previously attached to the folio and decrements
  * the refcount on the page.
  *
- * Return: Data that was attached to the page.
+ * Return: Data that was attached to the folio.
  */
-static inline void *detach_page_private(struct page *page)
+static inline void *folio_detach_private(struct folio *folio)
 {
-	void *data = (void *)page_private(page);
+	void *data = folio_get_private(folio);
 
-	if (!PagePrivate(page))
+	if (!folio_test_private(folio))
 		return NULL;
-	ClearPagePrivate(page);
+	folio_clear_private(folio);
-	set_page_private(page, 0);
+	folio->private = NULL;
-	put_page(page);
+	folio_put(folio);
 
 	return data;
 }
 
-#ifdef CONFIG_NUMA
+static inline void attach_page_private(struct page *page, void *data)
-extern struct page *__page_cache_alloc(gfp_t gfp);
-#else
-static inline struct page *__page_cache_alloc(gfp_t gfp)
 {
-	return alloc_pages(gfp, 0);
+	folio_attach_private(page_folio(page), data);
+}
+
+static inline void *detach_page_private(struct page *page)
+{
+	return folio_detach_private(page_folio(page));
+}
+
+#ifdef CONFIG_NUMA
+struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order);
+#else
+static inline struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order)
+{
+	return folio_alloc(gfp, order);
 }
 #endif
 
+static inline struct page *__page_cache_alloc(gfp_t gfp)
+{
+	return &filemap_alloc_folio(gfp, 0)->page;
+}
+
 static inline struct page *page_cache_alloc(struct address_space *x)
 {
 	return __page_cache_alloc(mapping_gfp_mask(x));
@@ -331,9 +301,28 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
 #define FGP_FOR_MMAP		0x00000040
 #define FGP_HEAD		0x00000080
 #define FGP_ENTRY		0x00000100
+#define FGP_STABLE		0x00000200
 
-struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
+struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
-		int fgp_flags, gfp_t cache_gfp_mask);
+		int fgp_flags, gfp_t gfp);
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
+		int fgp_flags, gfp_t gfp);
+
+/**
+ * filemap_get_folio - Find and get a folio.
+ * @mapping: The address_space to search.
+ * @index: The page index.
+ *
+ * Looks up the page cache entry at @mapping & @index.  If a folio is
+ * present, it is returned with an increased refcount.
+ *
+ * Otherwise, %NULL is returned.
+ */
+static inline struct folio *filemap_get_folio(struct address_space *mapping,
+					pgoff_t index)
+{
+	return __filemap_get_folio(mapping, index, 0, 0);
+}
 
 /**
  * find_get_page - find and get a page reference
@@ -376,25 +365,6 @@ static inline struct page *find_lock_page(struct address_space *mapping,
 	return pagecache_get_page(mapping, index, FGP_LOCK, 0);
 }
 
-/**
- * find_lock_head - Locate, pin and lock a pagecache page.
- * @mapping: The address_space to search.
- * @index: The page index.
- *
- * Looks up the page cache entry at @mapping & @index.  If there is a
- * page cache page, its head page is returned locked and with an increased
- * refcount.
- *
- * Context: May sleep.
- * Return: A struct page which is !PageTail, or %NULL if there is no page
- * in the cache for this index.
- */
-static inline struct page *find_lock_head(struct address_space *mapping,
-					pgoff_t index)
-{
-	return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0);
-}
-
 /**
  * find_or_create_page - locate or add a pagecache page
  * @mapping: the page's address_space
@@ -452,6 +422,73 @@ static inline bool thp_contains(struct page *head, pgoff_t index)
 	return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL));
 }
 
+#define swapcache_index(folio)	__page_file_index(&(folio)->page)
+
+/**
+ * folio_index - File index of a folio.
+ * @folio: The folio.
+ *
+ * For a folio which is either in the page cache or the swap cache,
+ * return its index within the address_space it belongs to.  If you know
+ * the page is definitely in the page cache, you can look at the folio's
+ * index directly.
+ *
+ * Return: The index (offset in units of pages) of a folio in its file.
+ */
+static inline pgoff_t folio_index(struct folio *folio)
+{
+        if (unlikely(folio_test_swapcache(folio)))
+                return swapcache_index(folio);
+        return folio->index;
+}
+
+/**
+ * folio_next_index - Get the index of the next folio.
+ * @folio: The current folio.
+ *
+ * Return: The index of the folio which follows this folio in the file.
+ */
+static inline pgoff_t folio_next_index(struct folio *folio)
+{
+	return folio->index + folio_nr_pages(folio);
+}
+
+/**
+ * folio_file_page - The page for a particular index.
+ * @folio: The folio which contains this index.
+ * @index: The index we want to look up.
+ *
+ * Sometimes after looking up a folio in the page cache, we need to
+ * obtain the specific page for an index (eg a page fault).
+ *
+ * Return: The page containing the file data for this index.
+ */
+static inline struct page *folio_file_page(struct folio *folio, pgoff_t index)
+{
+	/* HugeTLBfs indexes the page cache in units of hpage_size */
+	if (folio_test_hugetlb(folio))
+		return &folio->page;
+	return folio_page(folio, index & (folio_nr_pages(folio) - 1));
+}
+
+/**
+ * folio_contains - Does this folio contain this index?
+ * @folio: The folio.
+ * @index: The page index within the file.
+ *
+ * Context: The caller should have the page locked in order to prevent
+ * (eg) shmem from moving the page between the page cache and swap cache
+ * and changing its index in the middle of the operation.
+ * Return: true or false.
+ */
+static inline bool folio_contains(struct folio *folio, pgoff_t index)
+{
+	/* HugeTLBfs indexes the page cache in units of hpage_size */
+	if (folio_test_hugetlb(folio))
+		return folio->index == index;
+	return index - folio_index(folio) < folio_nr_pages(folio);
+}
+
 /*
  * Given the page we found in the page cache, return the page corresponding
  * to this index in the file
@@ -560,6 +597,27 @@ static inline loff_t page_file_offset(struct page *page)
 	return ((loff_t)page_index(page)) << PAGE_SHIFT;
 }
 
+/**
+ * folio_pos - Returns the byte position of this folio in its file.
+ * @folio: The folio.
+ */
+static inline loff_t folio_pos(struct folio *folio)
+{
+	return page_offset(&folio->page);
+}
+
+/**
+ * folio_file_pos - Returns the byte position of this folio in its file.
+ * @folio: The folio.
+ *
+ * This differs from folio_pos() for folios which belong to a swap file.
+ * NFS is the only filesystem today which needs to use folio_file_pos().
+ */
+static inline loff_t folio_file_pos(struct folio *folio)
+{
+	return page_file_offset(&folio->page);
+}
+
 extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
 				     unsigned long address);
 
@@ -575,13 +633,13 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
 }
 
 struct wait_page_key {
-	struct page *page;
+	struct folio *folio;
 	int bit_nr;
 	int page_match;
 };
 
 struct wait_page_queue {
-	struct page *page;
+	struct folio *folio;
 	int bit_nr;
 	wait_queue_entry_t wait;
 };
@@ -589,7 +647,7 @@ struct wait_page_queue {
 static inline bool wake_page_match(struct wait_page_queue *wait_page,
 				  struct wait_page_key *key)
 {
-	if (wait_page->page != key->page)
+	if (wait_page->folio != key->folio)
 	       return false;
 	key->page_match = 1;
 
@@ -599,20 +657,31 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page,
 	return true;
 }
 
-extern void __lock_page(struct page *page);
+void __folio_lock(struct folio *folio);
-extern int __lock_page_killable(struct page *page);
+int __folio_lock_killable(struct folio *folio);
-extern int __lock_page_async(struct page *page, struct wait_page_queue *wait);
+bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm,
-extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
 				unsigned int flags);
-extern void unlock_page(struct page *page);
+void unlock_page(struct page *page);
+void folio_unlock(struct folio *folio);
+
+static inline bool folio_trylock(struct folio *folio)
+{
+	return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio, 0)));
+}
 
 /*
  * Return true if the page was successfully locked
  */
 static inline int trylock_page(struct page *page)
 {
-	page = compound_head(page);
+	return folio_trylock(page_folio(page));
-	return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));
+}
+
+static inline void folio_lock(struct folio *folio)
+{
+	might_sleep();
+	if (!folio_trylock(folio))
+		__folio_lock(folio);
 }
 
 /*
@@ -620,9 +689,20 @@ static inline int trylock_page(struct page *page)
  */
 static inline void lock_page(struct page *page)
 {
+	struct folio *folio;
 	might_sleep();
-	if (!trylock_page(page))
+
-		__lock_page(page);
+	folio = page_folio(page);
+	if (!folio_trylock(folio))
+		__folio_lock(folio);
+}
+
+static inline int folio_lock_killable(struct folio *folio)
+{
+	might_sleep();
+	if (!folio_trylock(folio))
+		return __folio_lock_killable(folio);
+	return 0;
 }
 
 /*
@@ -632,26 +712,7 @@ static inline void lock_page(struct page *page)
  */
 static inline int lock_page_killable(struct page *page)
 {
-	might_sleep();
+	return folio_lock_killable(page_folio(page));
-	if (!trylock_page(page))
-		return __lock_page_killable(page);
-	return 0;
-}
-
-/*
- * lock_page_async - Lock the page, unless this would block. If the page
- * is already locked, then queue a callback when the page becomes unlocked.
- * This callback can then retry the operation.
- *
- * Returns 0 if the page is locked successfully, or -EIOCBQUEUED if the page
- * was already locked and the callback defined in 'wait' was queued.
- */
-static inline int lock_page_async(struct page *page,
-				  struct wait_page_queue *wait)
-{
-	if (!trylock_page(page))
-		return __lock_page_async(page, wait);
-	return 0;
 }
 
 /*
@@ -659,78 +720,108 @@ static inline int lock_page_async(struct page *page,
  * caller indicated that it can handle a retry.
  *
  * Return value and mmap_lock implications depend on flags; see
- * __lock_page_or_retry().
+ * __folio_lock_or_retry().
  */
-static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
+static inline bool lock_page_or_retry(struct page *page, struct mm_struct *mm,
 				     unsigned int flags)
 {
+	struct folio *folio;
 	might_sleep();
-	return trylock_page(page) || __lock_page_or_retry(page, mm, flags);
+
+	folio = page_folio(page);
+	return folio_trylock(folio) || __folio_lock_or_retry(folio, mm, flags);
 }
 
 /*
- * This is exported only for wait_on_page_locked/wait_on_page_writeback, etc.,
+ * This is exported only for folio_wait_locked/folio_wait_writeback, etc.,
  * and should not be used directly.
  */
-extern void wait_on_page_bit(struct page *page, int bit_nr);
+void folio_wait_bit(struct folio *folio, int bit_nr);
-extern int wait_on_page_bit_killable(struct page *page, int bit_nr);
+int folio_wait_bit_killable(struct folio *folio, int bit_nr);
 
 /* 
- * Wait for a page to be unlocked.
+ * Wait for a folio to be unlocked.
  *
- * This must be called with the caller "holding" the page,
+ * This must be called with the caller "holding" the folio,
- * ie with increased "page->count" so that the page won't
+ * ie with increased "page->count" so that the folio won't
  * go away during the wait..
  */
+static inline void folio_wait_locked(struct folio *folio)
+{
+	if (folio_test_locked(folio))
+		folio_wait_bit(folio, PG_locked);
+}
+
+static inline int folio_wait_locked_killable(struct folio *folio)
+{
+	if (!folio_test_locked(folio))
+		return 0;
+	return folio_wait_bit_killable(folio, PG_locked);
+}
+
 static inline void wait_on_page_locked(struct page *page)
 {
-	if (PageLocked(page))
+	folio_wait_locked(page_folio(page));
-		wait_on_page_bit(compound_head(page), PG_locked);
 }
 
 static inline int wait_on_page_locked_killable(struct page *page)
 {
-	if (!PageLocked(page))
+	return folio_wait_locked_killable(page_folio(page));
-		return 0;
-	return wait_on_page_bit_killable(compound_head(page), PG_locked);
 }
 
 int put_and_wait_on_page_locked(struct page *page, int state);
 void wait_on_page_writeback(struct page *page);
-int wait_on_page_writeback_killable(struct page *page);
+void folio_wait_writeback(struct folio *folio);
-extern void end_page_writeback(struct page *page);
+int folio_wait_writeback_killable(struct folio *folio);
+void end_page_writeback(struct page *page);
+void folio_end_writeback(struct folio *folio);
 void wait_for_stable_page(struct page *page);
+void folio_wait_stable(struct folio *folio);
+void __folio_mark_dirty(struct folio *folio, struct address_space *, int warn);
+static inline void __set_page_dirty(struct page *page,
+		struct address_space *mapping, int warn)
+{
+	__folio_mark_dirty(page_folio(page), mapping, warn);
+}
+void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
+			  struct bdi_writeback *wb);
+static inline void account_page_cleaned(struct page *page,
+		struct address_space *mapping, struct bdi_writeback *wb)
+{
+	return folio_account_cleaned(page_folio(page), mapping, wb);
+}
+void __folio_cancel_dirty(struct folio *folio);
+static inline void folio_cancel_dirty(struct folio *folio)
+{
+	/* Avoid atomic ops, locking, etc. when not actually needed. */
+	if (folio_test_dirty(folio))
+		__folio_cancel_dirty(folio);
+}
+static inline void cancel_dirty_page(struct page *page)
+{
+	folio_cancel_dirty(page_folio(page));
+}
+bool folio_clear_dirty_for_io(struct folio *folio);
+bool clear_page_dirty_for_io(struct page *page);
+int __must_check folio_write_one(struct folio *folio);
+static inline int __must_check write_one_page(struct page *page)
+{
+	return folio_write_one(page_folio(page));
+}
 
-void __set_page_dirty(struct page *, struct address_space *, int warn);
 int __set_page_dirty_nobuffers(struct page *page);
 int __set_page_dirty_no_writeback(struct page *page);
 
 void page_endio(struct page *page, bool is_write, int err);
 
-/**
+void folio_end_private_2(struct folio *folio);
- * set_page_private_2 - Set PG_private_2 on a page and take a ref
+void folio_wait_private_2(struct folio *folio);
- * @page: The page.
+int folio_wait_private_2_killable(struct folio *folio);
- *
- * Set the PG_private_2 flag on a page and take the reference needed for the VM
- * to handle its lifetime correctly.  This sets the flag and takes the
- * reference unconditionally, so care must be taken not to set the flag again
- * if it's already set.
- */
-static inline void set_page_private_2(struct page *page)
-{
-	page = compound_head(page);
-	get_page(page);
-	SetPagePrivate2(page);
-}
-
-void end_page_private_2(struct page *page);
-void wait_on_page_private_2(struct page *page);
-int wait_on_page_private_2_killable(struct page *page);
 
 /*
  * Add an arbitrary waiter to a page's wait queue
  */
-extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter);
+void folio_add_wait_queue(struct folio *folio, wait_queue_entry_t *waiter);
 
 /*
  * Fault everything in given userspace address range in.
@@ -790,9 +881,11 @@ static inline int fault_in_pages_readable(const char __user *uaddr, size_t size)
 }
 
 int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
-				pgoff_t index, gfp_t gfp_mask);
+		pgoff_t index, gfp_t gfp);
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
-				pgoff_t index, gfp_t gfp_mask);
+		pgoff_t index, gfp_t gfp);
+int filemap_add_folio(struct address_space *mapping, struct folio *folio,
+		pgoff_t index, gfp_t gfp);
 extern void delete_from_page_cache(struct page *page);
 extern void __delete_from_page_cache(struct page *page, void *shadow);
 void replace_page_cache_page(struct page *old, struct page *new);
@@ -817,6 +910,10 @@ static inline int add_to_page_cache(struct page *page,
 	return error;
 }
 
+/* Must be non-static for BPF error injection */
+int __filemap_add_folio(struct address_space *mapping, struct folio *folio,
+		pgoff_t index, gfp_t gfp, void **shadowp);
+
 /**
  * struct readahead_control - Describes a readahead request.
  *
@@ -906,33 +1003,57 @@ void page_cache_async_readahead(struct address_space *mapping,
 	page_cache_async_ra(&ractl, page, req_count);
 }
 
+static inline struct folio *__readahead_folio(struct readahead_control *ractl)
+{
+	struct folio *folio;
+
+	BUG_ON(ractl->_batch_count > ractl->_nr_pages);
+	ractl->_nr_pages -= ractl->_batch_count;
+	ractl->_index += ractl->_batch_count;
+
+	if (!ractl->_nr_pages) {
+		ractl->_batch_count = 0;
+		return NULL;
+	}
+
+	folio = xa_load(&ractl->mapping->i_pages, ractl->_index);
+	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
+	ractl->_batch_count = folio_nr_pages(folio);
+
+	return folio;
+}
+
 /**
  * readahead_page - Get the next page to read.
- * @rac: The current readahead request.
+ * @ractl: The current readahead request.
  *
  * Context: The page is locked and has an elevated refcount.  The caller
  * should decreases the refcount once the page has been submitted for I/O
  * and unlock the page once all I/O to that page has completed.
  * Return: A pointer to the next page, or %NULL if we are done.
  */
-static inline struct page *readahead_page(struct readahead_control *rac)
+static inline struct page *readahead_page(struct readahead_control *ractl)
 {
-	struct page *page;
+	struct folio *folio = __readahead_folio(ractl);
 
-	BUG_ON(rac->_batch_count > rac->_nr_pages);
+	return &folio->page;
-	rac->_nr_pages -= rac->_batch_count;
+}
-	rac->_index += rac->_batch_count;
 
-	if (!rac->_nr_pages) {
+/**
-		rac->_batch_count = 0;
+ * readahead_folio - Get the next folio to read.
-		return NULL;
+ * @ractl: The current readahead request.
-	}
+ *
+ * Context: The folio is locked.  The caller should unlock the folio once
+ * all I/O to that folio has completed.
+ * Return: A pointer to the next folio, or %NULL if we are done.
+ */
+static inline struct folio *readahead_folio(struct readahead_control *ractl)
+{
+	struct folio *folio = __readahead_folio(ractl);
 
-	page = xa_load(&rac->mapping->i_pages, rac->_index);
+	if (folio)
-	VM_BUG_ON_PAGE(!PageLocked(page), page);
+		folio_put(folio);
-	rac->_batch_count = thp_nr_pages(page);
+	return folio;
-
-	return page;
 }
 
 static inline unsigned int __readahead_batch(struct readahead_control *rac,
@@ -1039,6 +1160,34 @@ static inline unsigned long dir_pages(struct inode *inode)
 			       PAGE_SHIFT;
 }
 
+/**
+ * folio_mkwrite_check_truncate - check if folio was truncated
+ * @folio: the folio to check
+ * @inode: the inode to check the folio against
+ *
+ * Return: the number of bytes in the folio up to EOF,
+ * or -EFAULT if the folio was truncated.
+ */
+static inline ssize_t folio_mkwrite_check_truncate(struct folio *folio,
+					      struct inode *inode)
+{
+	loff_t size = i_size_read(inode);
+	pgoff_t index = size >> PAGE_SHIFT;
+	size_t offset = offset_in_folio(folio, size);
+
+	if (!folio->mapping)
+		return -EFAULT;
+
+	/* folio is wholly inside EOF */
+	if (folio_next_index(folio) - 1 < index)
+		return folio_size(folio);
+	/* folio is wholly past EOF */
+	if (folio->index > index || !offset)
+		return -EFAULT;
+	/* folio is partially inside EOF */
+	return offset;
+}
+
 /**
  * page_mkwrite_check_truncate - check if page was truncated
  * @page: the page to check
@@ -1068,19 +1217,25 @@ static inline int page_mkwrite_check_truncate(struct page *page,
 }
 
 /**
- * i_blocks_per_page - How many blocks fit in this page.
+ * i_blocks_per_folio - How many blocks fit in this folio.
  * @inode: The inode which contains the blocks.
- * @page: The page (head page if the page is a THP).
+ * @folio: The folio.
  *
- * If the block size is larger than the size of this page, return zero.
+ * If the block size is larger than the size of this folio, return zero.
  *
- * Context: The caller should hold a refcount on the page to prevent it
+ * Context: The caller should hold a refcount on the folio to prevent it
  * from being split.
- * Return: The number of filesystem blocks covered by this page.
+ * Return: The number of filesystem blocks covered by this folio.
  */
+static inline
+unsigned int i_blocks_per_folio(struct inode *inode, struct folio *folio)
+{
+	return folio_size(folio) >> inode->i_blkbits;
+}
+
 static inline
 unsigned int i_blocks_per_page(struct inode *inode, struct page *page)
 {
-	return thp_size(page) >> inode->i_blkbits;
+	return i_blocks_per_folio(inode, page_folio(page));
 }
 #endif /* _LINUX_PAGEMAP_H */

include/linux/rmap.h

@@ -235,7 +235,7 @@ unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
  *
  * returns the number of cleaned PTEs.
  */
-int page_mkclean(struct page *);
+int folio_mkclean(struct folio *);
 
 /*
  * called in munlock()/munmap() path to check for other vmas holding
@@ -295,12 +295,14 @@ static inline void try_to_unmap(struct page *page, enum ttu_flags flags)
 {
 }
 
-static inline int page_mkclean(struct page *page)
+static inline int folio_mkclean(struct folio *folio)
 {
 	return 0;
 }
-
-
 #endif	/* CONFIG_MMU */
 
+static inline int page_mkclean(struct page *page)
+{
+	return folio_mkclean(page_folio(page));
+}
 #endif	/* _LINUX_RMAP_H */

include/linux/swap.h

@@ -320,11 +320,17 @@ struct vma_swap_readahead {
 #endif
 };
 
+static inline swp_entry_t folio_swap_entry(struct folio *folio)
+{
+	swp_entry_t entry = { .val = page_private(&folio->page) };
+	return entry;
+}
+
 /* linux/mm/workingset.c */
 void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages);
 void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg);
-void workingset_refault(struct page *page, void *shadow);
+void workingset_refault(struct folio *folio, void *shadow);
-void workingset_activation(struct page *page);
+void workingset_activation(struct folio *folio);
 
 /* Only track the nodes of mappings with shadow entries */
 void workingset_update_node(struct xa_node *node);
@@ -344,9 +350,11 @@ extern unsigned long nr_free_buffer_pages(void);
 /* linux/mm/swap.c */
 extern void lru_note_cost(struct lruvec *lruvec, bool file,
 			  unsigned int nr_pages);
-extern void lru_note_cost_page(struct page *);
+extern void lru_note_cost_folio(struct folio *);
+extern void folio_add_lru(struct folio *);
 extern void lru_cache_add(struct page *);
-extern void mark_page_accessed(struct page *);
+void mark_page_accessed(struct page *);
+void folio_mark_accessed(struct folio *);
 
 extern atomic_t lru_disable_count;
 
@@ -365,7 +373,6 @@ extern void lru_add_drain(void);
 extern void lru_add_drain_cpu(int cpu);
 extern void lru_add_drain_cpu_zone(struct zone *zone);
 extern void lru_add_drain_all(void);
-extern void rotate_reclaimable_page(struct page *page);
 extern void deactivate_file_page(struct page *page);
 extern void deactivate_page(struct page *page);
 extern void mark_page_lazyfree(struct page *page);

include/linux/vmstat.h

@@ -415,6 +415,78 @@ static inline void drain_zonestat(struct zone *zone,
 			struct per_cpu_zonestat *pzstats) { }
 #endif		/* CONFIG_SMP */
 
+static inline void __zone_stat_mod_folio(struct folio *folio,
+		enum zone_stat_item item, long nr)
+{
+	__mod_zone_page_state(folio_zone(folio), item, nr);
+}
+
+static inline void __zone_stat_add_folio(struct folio *folio,
+		enum zone_stat_item item)
+{
+	__mod_zone_page_state(folio_zone(folio), item, folio_nr_pages(folio));
+}
+
+static inline void __zone_stat_sub_folio(struct folio *folio,
+		enum zone_stat_item item)
+{
+	__mod_zone_page_state(folio_zone(folio), item, -folio_nr_pages(folio));
+}
+
+static inline void zone_stat_mod_folio(struct folio *folio,
+		enum zone_stat_item item, long nr)
+{
+	mod_zone_page_state(folio_zone(folio), item, nr);
+}
+
+static inline void zone_stat_add_folio(struct folio *folio,
+		enum zone_stat_item item)
+{
+	mod_zone_page_state(folio_zone(folio), item, folio_nr_pages(folio));
+}
+
+static inline void zone_stat_sub_folio(struct folio *folio,
+		enum zone_stat_item item)
+{
+	mod_zone_page_state(folio_zone(folio), item, -folio_nr_pages(folio));
+}
+
+static inline void __node_stat_mod_folio(struct folio *folio,
+		enum node_stat_item item, long nr)
+{
+	__mod_node_page_state(folio_pgdat(folio), item, nr);
+}
+
+static inline void __node_stat_add_folio(struct folio *folio,
+		enum node_stat_item item)
+{
+	__mod_node_page_state(folio_pgdat(folio), item, folio_nr_pages(folio));
+}
+
+static inline void __node_stat_sub_folio(struct folio *folio,
+		enum node_stat_item item)
+{
+	__mod_node_page_state(folio_pgdat(folio), item, -folio_nr_pages(folio));
+}
+
+static inline void node_stat_mod_folio(struct folio *folio,
+		enum node_stat_item item, long nr)
+{
+	mod_node_page_state(folio_pgdat(folio), item, nr);
+}
+
+static inline void node_stat_add_folio(struct folio *folio,
+		enum node_stat_item item)
+{
+	mod_node_page_state(folio_pgdat(folio), item, folio_nr_pages(folio));
+}
+
+static inline void node_stat_sub_folio(struct folio *folio,
+		enum node_stat_item item)
+{
+	mod_node_page_state(folio_pgdat(folio), item, -folio_nr_pages(folio));
+}
+
 static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages,
 					     int migratetype)
 {
@@ -525,12 +597,6 @@ static inline void mod_lruvec_page_state(struct page *page,
 
 #endif /* CONFIG_MEMCG */
 
-static inline void inc_lruvec_state(struct lruvec *lruvec,
-				    enum node_stat_item idx)
-{
-	mod_lruvec_state(lruvec, idx, 1);
-}
-
 static inline void __inc_lruvec_page_state(struct page *page,
 					   enum node_stat_item idx)
 {
@@ -543,6 +609,24 @@ static inline void __dec_lruvec_page_state(struct page *page,
 	__mod_lruvec_page_state(page, idx, -1);
 }
 
+static inline void __lruvec_stat_mod_folio(struct folio *folio,
+					   enum node_stat_item idx, int val)
+{
+	__mod_lruvec_page_state(&folio->page, idx, val);
+}
+
+static inline void __lruvec_stat_add_folio(struct folio *folio,
+					   enum node_stat_item idx)
+{
+	__lruvec_stat_mod_folio(folio, idx, folio_nr_pages(folio));
+}
+
+static inline void __lruvec_stat_sub_folio(struct folio *folio,
+					   enum node_stat_item idx)
+{
+	__lruvec_stat_mod_folio(folio, idx, -folio_nr_pages(folio));
+}
+
 static inline void inc_lruvec_page_state(struct page *page,
 					 enum node_stat_item idx)
 {
@@ -555,4 +639,21 @@ static inline void dec_lruvec_page_state(struct page *page,
 	mod_lruvec_page_state(page, idx, -1);
 }
 
+static inline void lruvec_stat_mod_folio(struct folio *folio,
+					 enum node_stat_item idx, int val)
+{
+	mod_lruvec_page_state(&folio->page, idx, val);
+}
+
+static inline void lruvec_stat_add_folio(struct folio *folio,
+					 enum node_stat_item idx)
+{
+	lruvec_stat_mod_folio(folio, idx, folio_nr_pages(folio));
+}
+
+static inline void lruvec_stat_sub_folio(struct folio *folio,
+					 enum node_stat_item idx)
+{
+	lruvec_stat_mod_folio(folio, idx, -folio_nr_pages(folio));
+}
 #endif /* _LINUX_VMSTAT_H */

include/linux/writeback.h

@@ -393,7 +393,14 @@ void writeback_set_ratelimit(void);
 void tag_pages_for_writeback(struct address_space *mapping,
 			     pgoff_t start, pgoff_t end);
 
-void account_page_redirty(struct page *page);
+bool filemap_dirty_folio(struct address_space *mapping, struct folio *folio);
+void folio_account_redirty(struct folio *folio);
+static inline void account_page_redirty(struct page *page)
+{
+	folio_account_redirty(page_folio(page));
+}
+bool folio_redirty_for_writepage(struct writeback_control *, struct folio *);
+bool redirty_page_for_writepage(struct writeback_control *, struct page *);
 
 void sb_mark_inode_writeback(struct inode *inode);
 void sb_clear_inode_writeback(struct inode *inode);

include/trace/events/pagemap.h

@@ -16,38 +16,38 @@
 #define PAGEMAP_MAPPEDDISK	0x0020u
 #define PAGEMAP_BUFFERS		0x0040u
 
-#define trace_pagemap_flags(page) ( \
+#define trace_pagemap_flags(folio) ( \
-	(PageAnon(page)		? PAGEMAP_ANONYMOUS  : PAGEMAP_FILE) | \
+	(folio_test_anon(folio)		? PAGEMAP_ANONYMOUS  : PAGEMAP_FILE) | \
-	(page_mapped(page)	? PAGEMAP_MAPPED     : 0) | \
+	(folio_mapped(folio)		? PAGEMAP_MAPPED     : 0) | \
-	(PageSwapCache(page)	? PAGEMAP_SWAPCACHE  : 0) | \
+	(folio_test_swapcache(folio)	? PAGEMAP_SWAPCACHE  : 0) | \
-	(PageSwapBacked(page)	? PAGEMAP_SWAPBACKED : 0) | \
+	(folio_test_swapbacked(folio)	? PAGEMAP_SWAPBACKED : 0) | \
-	(PageMappedToDisk(page)	? PAGEMAP_MAPPEDDISK : 0) | \
+	(folio_test_mappedtodisk(folio)	? PAGEMAP_MAPPEDDISK : 0) | \
-	(page_has_private(page) ? PAGEMAP_BUFFERS    : 0) \
+	(folio_test_private(folio)	? PAGEMAP_BUFFERS    : 0) \
 	)
 
 TRACE_EVENT(mm_lru_insertion,
 
-	TP_PROTO(struct page *page),
+	TP_PROTO(struct folio *folio),
 
-	TP_ARGS(page),
+	TP_ARGS(folio),
 
 	TP_STRUCT__entry(
-		__field(struct page *,	page	)
+		__field(struct folio *,	folio	)
 		__field(unsigned long,	pfn	)
 		__field(enum lru_list,	lru	)
 		__field(unsigned long,	flags	)
 	),
 
 	TP_fast_assign(
-		__entry->page	= page;
+		__entry->folio	= folio;
-		__entry->pfn	= page_to_pfn(page);
+		__entry->pfn	= folio_pfn(folio);
-		__entry->lru	= page_lru(page);
+		__entry->lru	= folio_lru_list(folio);
-		__entry->flags	= trace_pagemap_flags(page);
+		__entry->flags	= trace_pagemap_flags(folio);
 	),
 
 	/* Flag format is based on page-types.c formatting for pagemap */
-	TP_printk("page=%p pfn=0x%lx lru=%d flags=%s%s%s%s%s%s",
+	TP_printk("folio=%p pfn=0x%lx lru=%d flags=%s%s%s%s%s%s",
-			__entry->page,
+			__entry->folio,
 			__entry->pfn,
 			__entry->lru,
 			__entry->flags & PAGEMAP_MAPPED		? "M" : " ",
@@ -60,23 +60,21 @@ TRACE_EVENT(mm_lru_insertion,
 
 TRACE_EVENT(mm_lru_activate,
 
-	TP_PROTO(struct page *page),
+	TP_PROTO(struct folio *folio),
 
-	TP_ARGS(page),
+	TP_ARGS(folio),
 
 	TP_STRUCT__entry(
-		__field(struct page *,	page	)
+		__field(struct folio *,	folio	)
 		__field(unsigned long,	pfn	)
 	),
 
 	TP_fast_assign(
-		__entry->page	= page;
+		__entry->folio	= folio;
-		__entry->pfn	= page_to_pfn(page);
+		__entry->pfn	= folio_pfn(folio);
 	),
 
-	/* Flag format is based on page-types.c formatting for pagemap */
+	TP_printk("folio=%p pfn=0x%lx", __entry->folio, __entry->pfn)
-	TP_printk("page=%p pfn=0x%lx", __entry->page, __entry->pfn)
-
 );
 
 #endif /* _TRACE_PAGEMAP_H */

include/trace/events/writeback.h

@@ -52,11 +52,11 @@ WB_WORK_REASON
 
 struct wb_writeback_work;
 
-DECLARE_EVENT_CLASS(writeback_page_template,
+DECLARE_EVENT_CLASS(writeback_folio_template,
 
-	TP_PROTO(struct page *page, struct address_space *mapping),
+	TP_PROTO(struct folio *folio, struct address_space *mapping),
 
-	TP_ARGS(page, mapping),
+	TP_ARGS(folio, mapping),
 
 	TP_STRUCT__entry (
 		__array(char, name, 32)
@@ -69,7 +69,7 @@ DECLARE_EVENT_CLASS(writeback_page_template,
 			    bdi_dev_name(mapping ? inode_to_bdi(mapping->host) :
 					 NULL), 32);
 		__entry->ino = mapping ? mapping->host->i_ino : 0;
-		__entry->index = page->index;
+		__entry->index = folio->index;
 	),
 
 	TP_printk("bdi %s: ino=%lu index=%lu",
@@ -79,18 +79,18 @@ DECLARE_EVENT_CLASS(writeback_page_template,
 	)
 );
 
-DEFINE_EVENT(writeback_page_template, writeback_dirty_page,
+DEFINE_EVENT(writeback_folio_template, writeback_dirty_folio,
 
-	TP_PROTO(struct page *page, struct address_space *mapping),
+	TP_PROTO(struct folio *folio, struct address_space *mapping),
 
-	TP_ARGS(page, mapping)
+	TP_ARGS(folio, mapping)
 );
 
-DEFINE_EVENT(writeback_page_template, wait_on_page_writeback,
+DEFINE_EVENT(writeback_folio_template, folio_wait_writeback,
 
-	TP_PROTO(struct page *page, struct address_space *mapping),
+	TP_PROTO(struct folio *folio, struct address_space *mapping),
 
-	TP_ARGS(page, mapping)
+	TP_ARGS(folio, mapping)
 );
 
 DECLARE_EVENT_CLASS(writeback_dirty_inode_template,
@@ -236,9 +236,9 @@ TRACE_EVENT(inode_switch_wbs,
 
 TRACE_EVENT(track_foreign_dirty,
 
-	TP_PROTO(struct page *page, struct bdi_writeback *wb),
+	TP_PROTO(struct folio *folio, struct bdi_writeback *wb),
 
-	TP_ARGS(page, wb),
+	TP_ARGS(folio, wb),
 
 	TP_STRUCT__entry(
 		__array(char,		name, 32)
@@ -250,7 +250,7 @@ TRACE_EVENT(track_foreign_dirty,
 	),
 
 	TP_fast_assign(
-		struct address_space *mapping = page_mapping(page);
+		struct address_space *mapping = folio_mapping(folio);
 		struct inode *inode = mapping ? mapping->host : NULL;
 
 		strscpy_pad(__entry->name, bdi_dev_name(wb->bdi), 32);
@@ -258,7 +258,7 @@ TRACE_EVENT(track_foreign_dirty,
 		__entry->ino		= inode ? inode->i_ino : 0;
 		__entry->memcg_id	= wb->memcg_css->id;
 		__entry->cgroup_ino	= __trace_wb_assign_cgroup(wb);
-		__entry->page_cgroup_ino = cgroup_ino(page_memcg(page)->css.cgroup);
+		__entry->page_cgroup_ino = cgroup_ino(folio_memcg(folio)->css.cgroup);
 	),
 
 	TP_printk("bdi %s[%llu]: ino=%lu memcg_id=%u cgroup_ino=%lu page_cgroup_ino=%lu",

kernel/bpf/verifier.c

@@ -13319,7 +13319,7 @@ BTF_SET_START(btf_non_sleepable_error_inject)
 /* Three functions below can be called from sleepable and non-sleepable context.
  * Assume non-sleepable from bpf safety point of view.
  */
-BTF_ID(func, __add_to_page_cache_locked)
+BTF_ID(func, __filemap_add_folio)
 BTF_ID(func, should_fail_alloc_page)
 BTF_ID(func, should_failslab)
 BTF_SET_END(btf_non_sleepable_error_inject)

kernel/events/uprobes.c

@@ -167,7 +167,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 				addr + PAGE_SIZE);
 
 	if (new_page) {
-		err = mem_cgroup_charge(new_page, vma->vm_mm, GFP_KERNEL);
+		err = mem_cgroup_charge(page_folio(new_page), vma->vm_mm,
+					GFP_KERNEL);
 		if (err)
 			return err;
 	}

lib/flex_proportions.c

@@ -217,11 +217,12 @@ static void fprop_reflect_period_percpu(struct fprop_global *p,
 }
 
 /* Event of type pl happened */
-void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)
+void __fprop_add_percpu(struct fprop_global *p, struct fprop_local_percpu *pl,
+		long nr)
 {
 	fprop_reflect_period_percpu(p, pl);
-	percpu_counter_add_batch(&pl->events, 1, PROP_BATCH);
+	percpu_counter_add_batch(&pl->events, nr, PROP_BATCH);
-	percpu_counter_add(&p->events, 1);
+	percpu_counter_add(&p->events, nr);
 }
 
 void fprop_fraction_percpu(struct fprop_global *p,
@@ -253,20 +254,29 @@ void fprop_fraction_percpu(struct fprop_global *p,
 }
 
 /*
- * Like __fprop_inc_percpu() except that event is counted only if the given
+ * Like __fprop_add_percpu() except that event is counted only if the given
  * type has fraction smaller than @max_frac/FPROP_FRAC_BASE
  */
-void __fprop_inc_percpu_max(struct fprop_global *p,
+void __fprop_add_percpu_max(struct fprop_global *p,
-			    struct fprop_local_percpu *pl, int max_frac)
+		struct fprop_local_percpu *pl, int max_frac, long nr)
 {
 	if (unlikely(max_frac < FPROP_FRAC_BASE)) {
 		unsigned long numerator, denominator;
+		s64 tmp;
 
 		fprop_fraction_percpu(p, pl, &numerator, &denominator);
-		if (numerator >
+		/* Adding 'nr' to fraction exceeds max_frac/FPROP_FRAC_BASE? */
-		    (((u64)denominator) * max_frac) >> FPROP_FRAC_SHIFT)
+		tmp = (u64)denominator * max_frac -
+					((u64)numerator << FPROP_FRAC_SHIFT);
+		if (tmp < 0) {
+			/* Maximum fraction already exceeded? */
 			return;
+		} else if (tmp < nr * (FPROP_FRAC_BASE - max_frac)) {
+			/* Add just enough for the fraction to saturate */
+			nr = div_u64(tmp + FPROP_FRAC_BASE - max_frac - 1,
+					FPROP_FRAC_BASE - max_frac);
+		}
 	}
 
-	__fprop_inc_percpu(p, pl);
+	__fprop_add_percpu(p, pl, nr);
 }

mm/Makefile

@@ -46,7 +46,7 @@ mmu-$(CONFIG_MMU)	+= process_vm_access.o
 endif
 
 obj-y			:= filemap.o mempool.o oom_kill.o fadvise.o \
-			   maccess.o page-writeback.o \
+			   maccess.o page-writeback.o folio-compat.o \
 			   readahead.o swap.o truncate.o vmscan.o shmem.o \
 			   util.o mmzone.o vmstat.o backing-dev.o \
 			   mm_init.o percpu.o slab_common.o \

mm/compaction.c

@@ -1022,7 +1022,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		if (!TestClearPageLRU(page))
 			goto isolate_fail_put;
 
-		lruvec = mem_cgroup_page_lruvec(page);
+		lruvec = folio_lruvec(page_folio(page));
 
 		/* If we already hold the lock, we can skip some rechecking */
 		if (lruvec != locked) {
@@ -1032,7 +1032,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 			compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
 			locked = lruvec;
 
-			lruvec_memcg_debug(lruvec, page);
+			lruvec_memcg_debug(lruvec, page_folio(page));
 
 			/* Try get exclusive access under lock */
 			if (!skip_updated) {

mm/folio-compat.c

@@ -0,0 +1,142 @@
+/*
+ * Compatibility functions which bloat the callers too much to make inline.
+ * All of the callers of these functions should be converted to use folios
+ * eventually.
+ */
+
+#include <linux/migrate.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+
+struct address_space *page_mapping(struct page *page)
+{
+	return folio_mapping(page_folio(page));
+}
+EXPORT_SYMBOL(page_mapping);
+
+void unlock_page(struct page *page)
+{
+	return folio_unlock(page_folio(page));
+}
+EXPORT_SYMBOL(unlock_page);
+
+void end_page_writeback(struct page *page)
+{
+	return folio_end_writeback(page_folio(page));
+}
+EXPORT_SYMBOL(end_page_writeback);
+
+void wait_on_page_writeback(struct page *page)
+{
+	return folio_wait_writeback(page_folio(page));
+}
+EXPORT_SYMBOL_GPL(wait_on_page_writeback);
+
+void wait_for_stable_page(struct page *page)
+{
+	return folio_wait_stable(page_folio(page));
+}
+EXPORT_SYMBOL_GPL(wait_for_stable_page);
+
+bool page_mapped(struct page *page)
+{
+	return folio_mapped(page_folio(page));
+}
+EXPORT_SYMBOL(page_mapped);
+
+void mark_page_accessed(struct page *page)
+{
+	folio_mark_accessed(page_folio(page));
+}
+EXPORT_SYMBOL(mark_page_accessed);
+
+#ifdef CONFIG_MIGRATION
+int migrate_page_move_mapping(struct address_space *mapping,
+		struct page *newpage, struct page *page, int extra_count)
+{
+	return folio_migrate_mapping(mapping, page_folio(newpage),
+					page_folio(page), extra_count);
+}
+EXPORT_SYMBOL(migrate_page_move_mapping);
+
+void migrate_page_states(struct page *newpage, struct page *page)
+{
+	folio_migrate_flags(page_folio(newpage), page_folio(page));
+}
+EXPORT_SYMBOL(migrate_page_states);
+
+void migrate_page_copy(struct page *newpage, struct page *page)
+{
+	folio_migrate_copy(page_folio(newpage), page_folio(page));
+}
+EXPORT_SYMBOL(migrate_page_copy);
+#endif
+
+bool set_page_writeback(struct page *page)
+{
+	return folio_start_writeback(page_folio(page));
+}
+EXPORT_SYMBOL(set_page_writeback);
+
+bool set_page_dirty(struct page *page)
+{
+	return folio_mark_dirty(page_folio(page));
+}
+EXPORT_SYMBOL(set_page_dirty);
+
+int __set_page_dirty_nobuffers(struct page *page)
+{
+	return filemap_dirty_folio(page_mapping(page), page_folio(page));
+}
+EXPORT_SYMBOL(__set_page_dirty_nobuffers);
+
+bool clear_page_dirty_for_io(struct page *page)
+{
+	return folio_clear_dirty_for_io(page_folio(page));
+}
+EXPORT_SYMBOL(clear_page_dirty_for_io);
+
+bool redirty_page_for_writepage(struct writeback_control *wbc,
+		struct page *page)
+{
+	return folio_redirty_for_writepage(wbc, page_folio(page));
+}
+EXPORT_SYMBOL(redirty_page_for_writepage);
+
+void lru_cache_add(struct page *page)
+{
+	folio_add_lru(page_folio(page));
+}
+EXPORT_SYMBOL(lru_cache_add);
+
+int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
+		pgoff_t index, gfp_t gfp)
+{
+	return filemap_add_folio(mapping, page_folio(page), index, gfp);
+}
+EXPORT_SYMBOL(add_to_page_cache_lru);
+
+noinline
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
+		int fgp_flags, gfp_t gfp)
+{
+	struct folio *folio;
+
+	folio = __filemap_get_folio(mapping, index, fgp_flags, gfp);
+	if ((fgp_flags & FGP_HEAD) || !folio || xa_is_value(folio))
+		return &folio->page;
+	return folio_file_page(folio, index);
+}
+EXPORT_SYMBOL(pagecache_get_page);
+
+struct page *grab_cache_page_write_begin(struct address_space *mapping,
+					pgoff_t index, unsigned flags)
+{
+	unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
+
+	if (flags & AOP_FLAG_NOFS)
+		fgp_flags |= FGP_NOFS;
+	return pagecache_get_page(mapping, index, fgp_flags,
+			mapping_gfp_mask(mapping));
+}
+EXPORT_SYMBOL(grab_cache_page_write_begin);

mm/huge_memory.c

@@ -603,7 +603,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 
 	VM_BUG_ON_PAGE(!PageCompound(page), page);
 
-	if (mem_cgroup_charge(page, vma->vm_mm, gfp)) {
+	if (mem_cgroup_charge(page_folio(page), vma->vm_mm, gfp)) {
 		put_page(page);
 		count_vm_event(THP_FAULT_FALLBACK);
 		count_vm_event(THP_FAULT_FALLBACK_CHARGE);
@@ -2405,7 +2405,8 @@ static void __split_huge_page_tail(struct page *head, int tail,
 static void __split_huge_page(struct page *page, struct list_head *list,
 		pgoff_t end)
 {
-	struct page *head = compound_head(page);
+	struct folio *folio = page_folio(page);
+	struct page *head = &folio->page;
 	struct lruvec *lruvec;
 	struct address_space *swap_cache = NULL;
 	unsigned long offset = 0;
@@ -2424,7 +2425,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
 	}
 
 	/* lock lru list/PageCompound, ref frozen by page_ref_freeze */
-	lruvec = lock_page_lruvec(head);
+	lruvec = folio_lruvec_lock(folio);
 
 	ClearPageHasHWPoisoned(head);
 

mm/hugetlb.c

@@ -5302,7 +5302,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			*pagep = NULL;
 			goto out;
 		}
-		copy_huge_page(page, *pagep);
+		folio_copy(page_folio(page), page_folio(*pagep));
 		put_page(*pagep);
 		*pagep = NULL;
 	}

mm/internal.h

@@ -34,7 +34,16 @@
 
 void page_writeback_init(void);
 
+static inline void *folio_raw_mapping(struct folio *folio)
+{
+	unsigned long mapping = (unsigned long)folio->mapping;
+
+	return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
+}
+
 vm_fault_t do_swap_page(struct vm_fault *vmf);
+void folio_rotate_reclaimable(struct folio *folio);
+bool __folio_end_writeback(struct folio *folio);
 
 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
 		unsigned long floor, unsigned long ceiling);
@@ -63,17 +72,28 @@ unsigned find_lock_entries(struct address_space *mapping, pgoff_t start,
 		pgoff_t end, struct pagevec *pvec, pgoff_t *indices);
 
 /**
- * page_evictable - test whether a page is evictable
+ * folio_evictable - Test whether a folio is evictable.
- * @page: the page to test
+ * @folio: The folio to test.
  *
- * Test whether page is evictable--i.e., should be placed on active/inactive
+ * Test whether @folio is evictable -- i.e., should be placed on
- * lists vs unevictable list.
+ * active/inactive lists vs unevictable list.
- *
- * Reasons page might not be evictable:
- * (1) page's mapping marked unevictable
- * (2) page is part of an mlocked VMA
  *
+ * Reasons folio might not be evictable:
+ * 1. folio's mapping marked unevictable
+ * 2. One of the pages in the folio is part of an mlocked VMA
  */
+static inline bool folio_evictable(struct folio *folio)
+{
+	bool ret;
+
+	/* Prevent address_space of inode and swap cache from being freed */
+	rcu_read_lock();
+	ret = !mapping_unevictable(folio_mapping(folio)) &&
+			!folio_test_mlocked(folio);
+	rcu_read_unlock();
+	return ret;
+}
+
 static inline bool page_evictable(struct page *page)
 {
 	bool ret;

mm/khugepaged.c

@@ -1090,7 +1090,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 		goto out_nolock;
 	}
 
-	if (unlikely(mem_cgroup_charge(new_page, mm, gfp))) {
+	if (unlikely(mem_cgroup_charge(page_folio(new_page), mm, gfp))) {
 		result = SCAN_CGROUP_CHARGE_FAIL;
 		goto out_nolock;
 	}
@@ -1214,7 +1214,7 @@ out_up_write:
 	mmap_write_unlock(mm);
 out_nolock:
 	if (!IS_ERR_OR_NULL(*hpage))
-		mem_cgroup_uncharge(*hpage);
+		mem_cgroup_uncharge(page_folio(*hpage));
 	trace_mm_collapse_huge_page(mm, isolated, result);
 	return;
 }
@@ -1661,7 +1661,7 @@ static void collapse_file(struct mm_struct *mm,
 		goto out;
 	}
 
-	if (unlikely(mem_cgroup_charge(new_page, mm, gfp))) {
+	if (unlikely(mem_cgroup_charge(page_folio(new_page), mm, gfp))) {
 		result = SCAN_CGROUP_CHARGE_FAIL;
 		goto out;
 	}
@@ -1983,7 +1983,7 @@ xa_unlocked:
 out:
 	VM_BUG_ON(!list_empty(&pagelist));
 	if (!IS_ERR_OR_NULL(*hpage))
-		mem_cgroup_uncharge(*hpage);
+		mem_cgroup_uncharge(page_folio(*hpage));
 	/* TODO: tracepoints */
 }
 

mm/ksm.c

@@ -751,7 +751,7 @@ stale:
 	/*
 	 * We come here from above when page->mapping or !PageSwapCache
 	 * suggests that the node is stale; but it might be under migration.
-	 * We need smp_rmb(), matching the smp_wmb() in ksm_migrate_page(),
+	 * We need smp_rmb(), matching the smp_wmb() in folio_migrate_ksm(),
 	 * before checking whether node->kpfn has been changed.
 	 */
 	smp_rmb();
@@ -852,9 +852,14 @@ static int unmerge_ksm_pages(struct vm_area_struct *vma,
 	return err;
 }
 
+static inline struct stable_node *folio_stable_node(struct folio *folio)
+{
+	return folio_test_ksm(folio) ? folio_raw_mapping(folio) : NULL;
+}
+
 static inline struct stable_node *page_stable_node(struct page *page)
 {
-	return PageKsm(page) ? page_rmapping(page) : NULL;
+	return folio_stable_node(page_folio(page));
 }
 
 static inline void set_page_stable_node(struct page *page,
@@ -2578,7 +2583,8 @@ struct page *ksm_might_need_to_copy(struct page *page,
 		return page;		/* let do_swap_page report the error */
 
 	new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
-	if (new_page && mem_cgroup_charge(new_page, vma->vm_mm, GFP_KERNEL)) {
+	if (new_page &&
+	    mem_cgroup_charge(page_folio(new_page), vma->vm_mm, GFP_KERNEL)) {
 		put_page(new_page);
 		new_page = NULL;
 	}
@@ -2658,26 +2664,26 @@ again:
 }
 
 #ifdef CONFIG_MIGRATION
-void ksm_migrate_page(struct page *newpage, struct page *oldpage)
+void folio_migrate_ksm(struct folio *newfolio, struct folio *folio)
 {
 	struct stable_node *stable_node;
 
-	VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
-	VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+	VM_BUG_ON_FOLIO(!folio_test_locked(newfolio), newfolio);
-	VM_BUG_ON_PAGE(newpage->mapping != oldpage->mapping, newpage);
+	VM_BUG_ON_FOLIO(newfolio->mapping != folio->mapping, newfolio);
 
-	stable_node = page_stable_node(newpage);
+	stable_node = folio_stable_node(folio);
 	if (stable_node) {
-		VM_BUG_ON_PAGE(stable_node->kpfn != page_to_pfn(oldpage), oldpage);
+		VM_BUG_ON_FOLIO(stable_node->kpfn != folio_pfn(folio), folio);
-		stable_node->kpfn = page_to_pfn(newpage);
+		stable_node->kpfn = folio_pfn(newfolio);
 		/*
-		 * newpage->mapping was set in advance; now we need smp_wmb()
+		 * newfolio->mapping was set in advance; now we need smp_wmb()
 		 * to make sure that the new stable_node->kpfn is visible
-		 * to get_ksm_page() before it can see that oldpage->mapping
+		 * to get_ksm_page() before it can see that folio->mapping
-		 * has gone stale (or that PageSwapCache has been cleared).
+		 * has gone stale (or that folio_test_swapcache has been cleared).
 		 */
 		smp_wmb();
-		set_page_stable_node(oldpage, NULL);
+		set_page_stable_node(&folio->page, NULL);
 	}
 }
 #endif /* CONFIG_MIGRATION */

mm/memcontrol.c

@@ -456,28 +456,6 @@ ino_t page_cgroup_ino(struct page *page)
 	return ino;
 }
 
-static struct mem_cgroup_per_node *
-mem_cgroup_page_nodeinfo(struct mem_cgroup *memcg, struct page *page)
-{
-	int nid = page_to_nid(page);
-
-	return memcg->nodeinfo[nid];
-}
-
-static struct mem_cgroup_tree_per_node *
-soft_limit_tree_node(int nid)
-{
-	return soft_limit_tree.rb_tree_per_node[nid];
-}
-
-static struct mem_cgroup_tree_per_node *
-soft_limit_tree_from_page(struct page *page)
-{
-	int nid = page_to_nid(page);
-
-	return soft_limit_tree.rb_tree_per_node[nid];
-}
-
 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
 					 struct mem_cgroup_tree_per_node *mctz,
 					 unsigned long new_usage_in_excess)
@@ -548,13 +526,13 @@ static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
 	return excess;
 }
 
-static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
+static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
 {
 	unsigned long excess;
 	struct mem_cgroup_per_node *mz;
 	struct mem_cgroup_tree_per_node *mctz;
 
-	mctz = soft_limit_tree_from_page(page);
+	mctz = soft_limit_tree.rb_tree_per_node[nid];
 	if (!mctz)
 		return;
 	/*
@@ -562,7 +540,7 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
 	 * because their event counter is not touched.
 	 */
 	for (; memcg; memcg = parent_mem_cgroup(memcg)) {
-		mz = mem_cgroup_page_nodeinfo(memcg, page);
+		mz = memcg->nodeinfo[nid];
 		excess = soft_limit_excess(memcg);
 		/*
 		 * We have to update the tree if mz is on RB-tree or
@@ -593,7 +571,7 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
 
 	for_each_node(nid) {
 		mz = memcg->nodeinfo[nid];
-		mctz = soft_limit_tree_node(nid);
+		mctz = soft_limit_tree.rb_tree_per_node[nid];
 		if (mctz)
 			mem_cgroup_remove_exceeded(mz, mctz);
 	}
@@ -799,7 +777,6 @@ static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 }
 
 static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
-					 struct page *page,
 					 int nr_pages)
 {
 	/* pagein of a big page is an event. So, ignore page size */
@@ -842,7 +819,7 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
  * Check events in order.
  *
  */
-static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
+static void memcg_check_events(struct mem_cgroup *memcg, int nid)
 {
 	/* threshold event is triggered in finer grain than soft limit */
 	if (unlikely(mem_cgroup_event_ratelimit(memcg,
@@ -853,7 +830,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 						MEM_CGROUP_TARGET_SOFTLIMIT);
 		mem_cgroup_threshold(memcg);
 		if (unlikely(do_softlimit))
-			mem_cgroup_update_tree(memcg, page);
+			mem_cgroup_update_tree(memcg, nid);
 	}
 }
 
@@ -1149,64 +1126,88 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
 }
 
 #ifdef CONFIG_DEBUG_VM
-void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
 {
 	struct mem_cgroup *memcg;
 
 	if (mem_cgroup_disabled())
 		return;
 
-	memcg = page_memcg(page);
+	memcg = folio_memcg(folio);
 
 	if (!memcg)
-		VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != root_mem_cgroup, page);
+		VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio);
 	else
-		VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != memcg, page);
+		VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio);
 }
 #endif
 
 /**
- * lock_page_lruvec - lock and return lruvec for a given page.
+ * folio_lruvec_lock - Lock the lruvec for a folio.
- * @page: the page
+ * @folio: Pointer to the folio.
  *
  * These functions are safe to use under any of the following conditions:
- * - page locked
+ * - folio locked
- * - PageLRU cleared
+ * - folio_test_lru false
- * - lock_page_memcg()
+ * - folio_memcg_lock()
- * - page->_refcount is zero
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held.
  */
-struct lruvec *lock_page_lruvec(struct page *page)
+struct lruvec *folio_lruvec_lock(struct folio *folio)
 {
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = mem_cgroup_page_lruvec(page);
 	spin_lock(&lruvec->lru_lock);
-
+	lruvec_memcg_debug(lruvec, folio);
-	lruvec_memcg_debug(lruvec, page);
 
 	return lruvec;
 }
 
-struct lruvec *lock_page_lruvec_irq(struct page *page)
+/**
+ * folio_lruvec_lock_irq - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
+ *
+ * These functions are safe to use under any of the following conditions:
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held and interrupts
+ * disabled.
+ */
+struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
 {
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = mem_cgroup_page_lruvec(page);
 	spin_lock_irq(&lruvec->lru_lock);
-
+	lruvec_memcg_debug(lruvec, folio);
-	lruvec_memcg_debug(lruvec, page);
 
 	return lruvec;
 }
 
-struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
+/**
+ * folio_lruvec_lock_irqsave - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
+ * @flags: Pointer to irqsave flags.
+ *
+ * These functions are safe to use under any of the following conditions:
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held and interrupts
+ * disabled.
+ */
+struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
+		unsigned long *flags)
 {
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = mem_cgroup_page_lruvec(page);
 	spin_lock_irqsave(&lruvec->lru_lock, *flags);
-
+	lruvec_memcg_debug(lruvec, folio);
-	lruvec_memcg_debug(lruvec, page);
 
 	return lruvec;
 }
@@ -1956,18 +1957,17 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
 }
 
 /**
- * lock_page_memcg - lock a page and memcg binding
+ * folio_memcg_lock - Bind a folio to its memcg.
- * @page: the page
+ * @folio: The folio.
  *
- * This function protects unlocked LRU pages from being moved to
+ * This function prevents unlocked LRU folios from being moved to
  * another cgroup.
  *
- * It ensures lifetime of the locked memcg. Caller is responsible
+ * It ensures lifetime of the bound memcg.  The caller is responsible
- * for the lifetime of the page.
+ * for the lifetime of the folio.
  */
-void lock_page_memcg(struct page *page)
+void folio_memcg_lock(struct folio *folio)
 {
-	struct page *head = compound_head(page); /* rmap on tail pages */
 	struct mem_cgroup *memcg;
 	unsigned long flags;
 
@@ -1981,7 +1981,7 @@ void lock_page_memcg(struct page *page)
 	if (mem_cgroup_disabled())
 		return;
 again:
-	memcg = page_memcg(head);
+	memcg = folio_memcg(folio);
 	if (unlikely(!memcg))
 		return;
 
@@ -1995,7 +1995,7 @@ again:
 		return;
 
 	spin_lock_irqsave(&memcg->move_lock, flags);
-	if (memcg != page_memcg(head)) {
+	if (memcg != folio_memcg(folio)) {
 		spin_unlock_irqrestore(&memcg->move_lock, flags);
 		goto again;
 	}
@@ -2009,9 +2009,15 @@ again:
 	memcg->move_lock_task = current;
 	memcg->move_lock_flags = flags;
 }
+EXPORT_SYMBOL(folio_memcg_lock);
+
+void lock_page_memcg(struct page *page)
+{
+	folio_memcg_lock(page_folio(page));
+}
 EXPORT_SYMBOL(lock_page_memcg);
 
-static void __unlock_page_memcg(struct mem_cgroup *memcg)
+static void __folio_memcg_unlock(struct mem_cgroup *memcg)
 {
 	if (memcg && memcg->move_lock_task == current) {
 		unsigned long flags = memcg->move_lock_flags;
@@ -2026,14 +2032,22 @@ static void __unlock_page_memcg(struct mem_cgroup *memcg)
 }
 
 /**
- * unlock_page_memcg - unlock a page and memcg binding
+ * folio_memcg_unlock - Release the binding between a folio and its memcg.
- * @page: the page
+ * @folio: The folio.
+ *
+ * This releases the binding created by folio_memcg_lock().  This does
+ * not change the accounting of this folio to its memcg, but it does
+ * permit others to change it.
  */
+void folio_memcg_unlock(struct folio *folio)
+{
+	__folio_memcg_unlock(folio_memcg(folio));
+}
+EXPORT_SYMBOL(folio_memcg_unlock);
+
 void unlock_page_memcg(struct page *page)
 {
-	struct page *head = compound_head(page);
+	folio_memcg_unlock(page_folio(page));
-
-	__unlock_page_memcg(page_memcg(head));
 }
 EXPORT_SYMBOL(unlock_page_memcg);
 
@@ -2734,9 +2748,9 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
 }
 #endif
 
-static void commit_charge(struct page *page, struct mem_cgroup *memcg)
+static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
 {
-	VM_BUG_ON_PAGE(page_memcg(page), page);
+	VM_BUG_ON_FOLIO(folio_memcg(folio), folio);
 	/*
 	 * Any of the following ensures page's memcg stability:
 	 *
@@ -2745,7 +2759,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg)
 	 * - lock_page_memcg()
 	 * - exclusive reference
 	 */
-	page->memcg_data = (unsigned long)memcg;
+	folio->memcg_data = (unsigned long)memcg;
 }
 
 static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
@@ -3015,15 +3029,16 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
  */
 void __memcg_kmem_uncharge_page(struct page *page, int order)
 {
+	struct folio *folio = page_folio(page);
 	struct obj_cgroup *objcg;
 	unsigned int nr_pages = 1 << order;
 
-	if (!PageMemcgKmem(page))
+	if (!folio_memcg_kmem(folio))
 		return;
 
-	objcg = __page_objcg(page);
+	objcg = __folio_objcg(folio);
 	obj_cgroup_uncharge_pages(objcg, nr_pages);
-	page->memcg_data = 0;
+	folio->memcg_data = 0;
 	obj_cgroup_put(objcg);
 }
 
@@ -3257,17 +3272,18 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
  */
 void split_page_memcg(struct page *head, unsigned int nr)
 {
-	struct mem_cgroup *memcg = page_memcg(head);
+	struct folio *folio = page_folio(head);
+	struct mem_cgroup *memcg = folio_memcg(folio);
 	int i;
 
 	if (mem_cgroup_disabled() || !memcg)
 		return;
 
 	for (i = 1; i < nr; i++)
-		head[i].memcg_data = head->memcg_data;
+		folio_page(folio, i)->memcg_data = folio->memcg_data;
 
-	if (PageMemcgKmem(head))
+	if (folio_memcg_kmem(folio))
-		obj_cgroup_get_many(__page_objcg(head), nr - 1);
+		obj_cgroup_get_many(__folio_objcg(folio), nr - 1);
 	else
 		css_get_many(&memcg->css, nr - 1);
 }
@@ -3381,7 +3397,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
 	if (order > 0)
 		return 0;
 
-	mctz = soft_limit_tree_node(pgdat->node_id);
+	mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id];
 
 	/*
 	 * Do not even bother to check the largest node if the root
@@ -4537,17 +4553,17 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
  * As being wrong occasionally doesn't matter, updates and accesses to the
  * records are lockless and racy.
  */
-void mem_cgroup_track_foreign_dirty_slowpath(struct page *page,
+void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio,
 					     struct bdi_writeback *wb)
 {
-	struct mem_cgroup *memcg = page_memcg(page);
+	struct mem_cgroup *memcg = folio_memcg(folio);
 	struct memcg_cgwb_frn *frn;
 	u64 now = get_jiffies_64();
 	u64 oldest_at = now;
 	int oldest = -1;
 	int i;
 
-	trace_track_foreign_dirty(page, wb);
+	trace_track_foreign_dirty(folio, wb);
 
 	/*
 	 * Pick the slot to use.  If there is already a slot for @wb, keep
@@ -5575,38 +5591,39 @@ static int mem_cgroup_move_account(struct page *page,
 				   struct mem_cgroup *from,
 				   struct mem_cgroup *to)
 {
+	struct folio *folio = page_folio(page);
 	struct lruvec *from_vec, *to_vec;
 	struct pglist_data *pgdat;
-	unsigned int nr_pages = compound ? thp_nr_pages(page) : 1;
+	unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1;
-	int ret;
+	int nid, ret;
 
 	VM_BUG_ON(from == to);
-	VM_BUG_ON_PAGE(PageLRU(page), page);
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
-	VM_BUG_ON(compound && !PageTransHuge(page));
+	VM_BUG_ON(compound && !folio_test_multi(folio));
 
 	/*
 	 * Prevent mem_cgroup_migrate() from looking at
 	 * page's memory cgroup of its source page while we change it.
 	 */
 	ret = -EBUSY;
-	if (!trylock_page(page))
+	if (!folio_trylock(folio))
 		goto out;
 
 	ret = -EINVAL;
-	if (page_memcg(page) != from)
+	if (folio_memcg(folio) != from)
 		goto out_unlock;
 
-	pgdat = page_pgdat(page);
+	pgdat = folio_pgdat(folio);
 	from_vec = mem_cgroup_lruvec(from, pgdat);
 	to_vec = mem_cgroup_lruvec(to, pgdat);
 
-	lock_page_memcg(page);
+	folio_memcg_lock(folio);
 
-	if (PageAnon(page)) {
+	if (folio_test_anon(folio)) {
-		if (page_mapped(page)) {
+		if (folio_mapped(folio)) {
 			__mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages);
 			__mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages);
-			if (PageTransHuge(page)) {
+			if (folio_test_transhuge(folio)) {
 				__mod_lruvec_state(from_vec, NR_ANON_THPS,
 						   -nr_pages);
 				__mod_lruvec_state(to_vec, NR_ANON_THPS,
@@ -5617,18 +5634,18 @@ static int mem_cgroup_move_account(struct page *page,
 		__mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
 		__mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages);
 
-		if (PageSwapBacked(page)) {
+		if (folio_test_swapbacked(folio)) {
 			__mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages);
 			__mod_lruvec_state(to_vec, NR_SHMEM, nr_pages);
 		}
 
-		if (page_mapped(page)) {
+		if (folio_mapped(folio)) {
 			__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
 			__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
 		}
 
-		if (PageDirty(page)) {
+		if (folio_test_dirty(folio)) {
-			struct address_space *mapping = page_mapping(page);
+			struct address_space *mapping = folio_mapping(folio);
 
 			if (mapping_can_writeback(mapping)) {
 				__mod_lruvec_state(from_vec, NR_FILE_DIRTY,
@@ -5639,7 +5656,7 @@ static int mem_cgroup_move_account(struct page *page,
 		}
 	}
 
-	if (PageWriteback(page)) {
+	if (folio_test_writeback(folio)) {
 		__mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages);
 		__mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages);
 	}
@@ -5662,20 +5679,21 @@ static int mem_cgroup_move_account(struct page *page,
 	css_get(&to->css);
 	css_put(&from->css);
 
-	page->memcg_data = (unsigned long)to;
+	folio->memcg_data = (unsigned long)to;
 
-	__unlock_page_memcg(from);
+	__folio_memcg_unlock(from);
 
 	ret = 0;
+	nid = folio_nid(folio);
 
 	local_irq_disable();
-	mem_cgroup_charge_statistics(to, page, nr_pages);
+	mem_cgroup_charge_statistics(to, nr_pages);
-	memcg_check_events(to, page);
+	memcg_check_events(to, nid);
-	mem_cgroup_charge_statistics(from, page, -nr_pages);
+	mem_cgroup_charge_statistics(from, -nr_pages);
-	memcg_check_events(from, page);
+	memcg_check_events(from, nid);
 	local_irq_enable();
 out_unlock:
-	unlock_page(page);
+	folio_unlock(folio);
 out:
 	return ret;
 }
@@ -6680,9 +6698,10 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root,
 			atomic_long_read(&parent->memory.children_low_usage)));
 }
 
-static int charge_memcg(struct page *page, struct mem_cgroup *memcg, gfp_t gfp)
+static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg,
+			gfp_t gfp)
 {
-	unsigned int nr_pages = thp_nr_pages(page);
+	long nr_pages = folio_nr_pages(folio);
 	int ret;
 
 	ret = try_charge(memcg, gfp, nr_pages);
@@ -6690,38 +6709,23 @@ static int charge_memcg(struct page *page, struct mem_cgroup *memcg, gfp_t gfp)
 		goto out;
 
 	css_get(&memcg->css);
-	commit_charge(page, memcg);
+	commit_charge(folio, memcg);
 
 	local_irq_disable();
-	mem_cgroup_charge_statistics(memcg, page, nr_pages);
+	mem_cgroup_charge_statistics(memcg, nr_pages);
-	memcg_check_events(memcg, page);
+	memcg_check_events(memcg, folio_nid(folio));
 	local_irq_enable();
 out:
 	return ret;
 }
 
-/**
+int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp)
- * __mem_cgroup_charge - charge a newly allocated page to a cgroup
- * @page: page to charge
- * @mm: mm context of the victim
- * @gfp_mask: reclaim mode
- *
- * Try to charge @page to the memcg that @mm belongs to, reclaiming
- * pages according to @gfp_mask if necessary. if @mm is NULL, try to
- * charge to the active memcg.
- *
- * Do not use this for pages allocated for swapin.
- *
- * Returns 0 on success. Otherwise, an error code is returned.
- */
-int __mem_cgroup_charge(struct page *page, struct mm_struct *mm,
-			gfp_t gfp_mask)
 {
 	struct mem_cgroup *memcg;
 	int ret;
 
 	memcg = get_mem_cgroup_from_mm(mm);
-	ret = charge_memcg(page, memcg, gfp_mask);
+	ret = charge_memcg(folio, memcg, gfp);
 	css_put(&memcg->css);
 
 	return ret;
@@ -6742,6 +6746,7 @@ int __mem_cgroup_charge(struct page *page, struct mm_struct *mm,
 int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
 				  gfp_t gfp, swp_entry_t entry)
 {
+	struct folio *folio = page_folio(page);
 	struct mem_cgroup *memcg;
 	unsigned short id;
 	int ret;
@@ -6756,7 +6761,7 @@ int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
 		memcg = get_mem_cgroup_from_mm(mm);
 	rcu_read_unlock();
 
-	ret = charge_memcg(page, memcg, gfp);
+	ret = charge_memcg(folio, memcg, gfp);
 
 	css_put(&memcg->css);
 	return ret;
@@ -6800,7 +6805,7 @@ struct uncharge_gather {
 	unsigned long nr_memory;
 	unsigned long pgpgout;
 	unsigned long nr_kmem;
-	struct page *dummy_page;
+	int nid;
 };
 
 static inline void uncharge_gather_clear(struct uncharge_gather *ug)
@@ -6824,36 +6829,36 @@ static void uncharge_batch(const struct uncharge_gather *ug)
 	local_irq_save(flags);
 	__count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout);
 	__this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory);
-	memcg_check_events(ug->memcg, ug->dummy_page);
+	memcg_check_events(ug->memcg, ug->nid);
 	local_irq_restore(flags);
 
-	/* drop reference from uncharge_page */
+	/* drop reference from uncharge_folio */
 	css_put(&ug->memcg->css);
 }
 
-static void uncharge_page(struct page *page, struct uncharge_gather *ug)
+static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug)
 {
-	unsigned long nr_pages;
+	long nr_pages;
 	struct mem_cgroup *memcg;
 	struct obj_cgroup *objcg;
-	bool use_objcg = PageMemcgKmem(page);
+	bool use_objcg = folio_memcg_kmem(folio);
 
-	VM_BUG_ON_PAGE(PageLRU(page), page);
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
 
 	/*
 	 * Nobody should be changing or seriously looking at
-	 * page memcg or objcg at this point, we have fully
+	 * folio memcg or objcg at this point, we have fully
-	 * exclusive access to the page.
+	 * exclusive access to the folio.
 	 */
 	if (use_objcg) {
-		objcg = __page_objcg(page);
+		objcg = __folio_objcg(folio);
 		/*
 		 * This get matches the put at the end of the function and
 		 * kmem pages do not hold memcg references anymore.
 		 */
 		memcg = get_mem_cgroup_from_objcg(objcg);
 	} else {
-		memcg = __page_memcg(page);
+		memcg = __folio_memcg(folio);
 	}
 
 	if (!memcg)
@@ -6865,19 +6870,19 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 			uncharge_gather_clear(ug);
 		}
 		ug->memcg = memcg;
-		ug->dummy_page = page;
+		ug->nid = folio_nid(folio);
 
 		/* pairs with css_put in uncharge_batch */
 		css_get(&memcg->css);
 	}
 
-	nr_pages = compound_nr(page);
+	nr_pages = folio_nr_pages(folio);
 
 	if (use_objcg) {
 		ug->nr_memory += nr_pages;
 		ug->nr_kmem += nr_pages;
 
-		page->memcg_data = 0;
+		folio->memcg_data = 0;
 		obj_cgroup_put(objcg);
 	} else {
 		/* LRU pages aren't accounted at the root level */
@@ -6885,28 +6890,22 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 			ug->nr_memory += nr_pages;
 		ug->pgpgout++;
 
-		page->memcg_data = 0;
+		folio->memcg_data = 0;
 	}
 
 	css_put(&memcg->css);
 }
 
-/**
+void __mem_cgroup_uncharge(struct folio *folio)
- * __mem_cgroup_uncharge - uncharge a page
- * @page: page to uncharge
- *
- * Uncharge a page previously charged with __mem_cgroup_charge().
- */
-void __mem_cgroup_uncharge(struct page *page)
 {
 	struct uncharge_gather ug;
 
-	/* Don't touch page->lru of any random page, pre-check: */
+	/* Don't touch folio->lru of any random page, pre-check: */
-	if (!page_memcg(page))
+	if (!folio_memcg(folio))
 		return;
 
 	uncharge_gather_clear(&ug);
-	uncharge_page(page, &ug);
+	uncharge_folio(folio, &ug);
 	uncharge_batch(&ug);
 }
 
@@ -6920,52 +6919,49 @@ void __mem_cgroup_uncharge(struct page *page)
 void __mem_cgroup_uncharge_list(struct list_head *page_list)
 {
 	struct uncharge_gather ug;
-	struct page *page;
+	struct folio *folio;
 
 	uncharge_gather_clear(&ug);
-	list_for_each_entry(page, page_list, lru)
+	list_for_each_entry(folio, page_list, lru)
-		uncharge_page(page, &ug);
+		uncharge_folio(folio, &ug);
 	if (ug.memcg)
 		uncharge_batch(&ug);
 }
 
 /**
- * mem_cgroup_migrate - charge a page's replacement
+ * mem_cgroup_migrate - Charge a folio's replacement.
- * @oldpage: currently circulating page
+ * @old: Currently circulating folio.
- * @newpage: replacement page
+ * @new: Replacement folio.
  *
- * Charge @newpage as a replacement page for @oldpage. @oldpage will
+ * Charge @new as a replacement folio for @old. @old will
  * be uncharged upon free.
  *
- * Both pages must be locked, @newpage->mapping must be set up.
+ * Both folios must be locked, @new->mapping must be set up.
  */
-void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
+void mem_cgroup_migrate(struct folio *old, struct folio *new)
 {
 	struct mem_cgroup *memcg;
-	unsigned int nr_pages;
+	long nr_pages = folio_nr_pages(new);
 	unsigned long flags;
 
-	VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+	VM_BUG_ON_FOLIO(!folio_test_locked(old), old);
-	VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+	VM_BUG_ON_FOLIO(!folio_test_locked(new), new);
-	VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
+	VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new);
-	VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
+	VM_BUG_ON_FOLIO(folio_nr_pages(old) != nr_pages, new);
-		       newpage);
 
 	if (mem_cgroup_disabled())
 		return;
 
-	/* Page cache replacement: new page already charged? */
+	/* Page cache replacement: new folio already charged? */
-	if (page_memcg(newpage))
+	if (folio_memcg(new))
 		return;
 
-	memcg = page_memcg(oldpage);
+	memcg = folio_memcg(old);
-	VM_WARN_ON_ONCE_PAGE(!memcg, oldpage);
+	VM_WARN_ON_ONCE_FOLIO(!memcg, old);
 	if (!memcg)
 		return;
 
 	/* Force-charge the new page. The old one will be freed soon */
-	nr_pages = thp_nr_pages(newpage);
-
 	if (!mem_cgroup_is_root(memcg)) {
 		page_counter_charge(&memcg->memory, nr_pages);
 		if (do_memsw_account())
@@ -6973,11 +6969,11 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
 	}
 
 	css_get(&memcg->css);
-	commit_charge(newpage, memcg);
+	commit_charge(new, memcg);
 
 	local_irq_save(flags);
-	mem_cgroup_charge_statistics(memcg, newpage, nr_pages);
+	mem_cgroup_charge_statistics(memcg, nr_pages);
-	memcg_check_events(memcg, newpage);
+	memcg_check_events(memcg, folio_nid(new));
 	local_irq_restore(flags);
 }
 
@@ -7204,8 +7200,8 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
 	 * only synchronisation we have for updating the per-CPU variables.
 	 */
 	VM_BUG_ON(!irqs_disabled());
-	mem_cgroup_charge_statistics(memcg, page, -nr_entries);
+	mem_cgroup_charge_statistics(memcg, -nr_entries);
-	memcg_check_events(memcg, page);
+	memcg_check_events(memcg, page_to_nid(page));
 
 	css_put(&memcg->css);
 }

mm/memory-failure.c

@@ -762,7 +762,7 @@ static int delete_from_lru_cache(struct page *p)
 		 * Poisoned page might never drop its ref count to 0 so we have
 		 * to uncharge it manually from its memcg.
 		 */
-		mem_cgroup_uncharge(p);
+		mem_cgroup_uncharge(page_folio(p));
 
 		/*
 		 * drop the page count elevated by isolate_lru_page()

mm/memory.c

@@ -990,7 +990,7 @@ page_copy_prealloc(struct mm_struct *src_mm, struct vm_area_struct *vma,
 	if (!new_page)
 		return NULL;
 
-	if (mem_cgroup_charge(new_page, src_mm, GFP_KERNEL)) {
+	if (mem_cgroup_charge(page_folio(new_page), src_mm, GFP_KERNEL)) {
 		put_page(new_page);
 		return NULL;
 	}
@@ -3019,7 +3019,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 		}
 	}
 
-	if (mem_cgroup_charge(new_page, mm, GFP_KERNEL))
+	if (mem_cgroup_charge(page_folio(new_page), mm, GFP_KERNEL))
 		goto oom_free_new;
 	cgroup_throttle_swaprate(new_page, GFP_KERNEL);
 
@@ -3539,7 +3539,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 
 				shadow = get_shadow_from_swap_cache(entry);
 				if (shadow)
-					workingset_refault(page, shadow);
+					workingset_refault(page_folio(page),
+								shadow);
 
 				lru_cache_add(page);
 
@@ -3769,7 +3770,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	if (!page)
 		goto oom;
 
-	if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL))
+	if (mem_cgroup_charge(page_folio(page), vma->vm_mm, GFP_KERNEL))
 		goto oom_free_page;
 	cgroup_throttle_swaprate(page, GFP_KERNEL);
 
@@ -4202,7 +4203,8 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf)
 	if (!vmf->cow_page)
 		return VM_FAULT_OOM;
 
-	if (mem_cgroup_charge(vmf->cow_page, vma->vm_mm, GFP_KERNEL)) {
+	if (mem_cgroup_charge(page_folio(vmf->cow_page), vma->vm_mm,
+				GFP_KERNEL)) {
 		put_page(vmf->cow_page);
 		return VM_FAULT_OOM;
 	}
@@ -4267,7 +4269,7 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf)
  * We enter with non-exclusive mmap_lock (to exclude vma changes,
  * but allow concurrent faults).
  * The mmap_lock may have been released depending on flags and our
- * return value.  See filemap_fault() and __lock_page_or_retry().
+ * return value.  See filemap_fault() and __folio_lock_or_retry().
  * If mmap_lock is released, vma may become invalid (for example
  * by other thread calling munmap()).
  */
@@ -4508,7 +4510,7 @@ static vm_fault_t wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
  * concurrent faults).
  *
  * The mmap_lock may have been released depending on flags and our return value.
- * See filemap_fault() and __lock_page_or_retry().
+ * See filemap_fault() and __folio_lock_or_retry().
  */
 static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 {
@@ -4612,7 +4614,7 @@ unlock:
  * By the time we get here, we already hold the mm semaphore
  *
  * The mmap_lock may have been released depending on flags and our
- * return value.  See filemap_fault() and __lock_page_or_retry().
+ * return value.  See filemap_fault() and __folio_lock_or_retry().
  */
 static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
 		unsigned long address, unsigned int flags)
@@ -4768,7 +4770,7 @@ static inline void mm_account_fault(struct pt_regs *regs,
  * By the time we get here, we already hold the mm semaphore
  *
  * The mmap_lock may have been released depending on flags and our
- * return value.  See filemap_fault() and __lock_page_or_retry().
+ * return value.  See filemap_fault() and __folio_lock_or_retry().
  */
 vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 			   unsigned int flags, struct pt_regs *regs)

mm/mempolicy.c

@@ -2196,6 +2196,16 @@ struct page *alloc_pages(gfp_t gfp, unsigned order)
 }
 EXPORT_SYMBOL(alloc_pages);
 
+struct folio *folio_alloc(gfp_t gfp, unsigned order)
+{
+	struct page *page = alloc_pages(gfp | __GFP_COMP, order);
+
+	if (page && order > 1)
+		prep_transhuge_page(page);
+	return (struct folio *)page;
+}
+EXPORT_SYMBOL(folio_alloc);
+
 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
 {
 	struct mempolicy *pol = mpol_dup(vma_policy(src));

mm/memremap.c

@@ -505,7 +505,7 @@ void free_devmap_managed_page(struct page *page)
 
 	__ClearPageWaiters(page);
 
-	mem_cgroup_uncharge(page);
+	mem_cgroup_uncharge(page_folio(page));
 
 	/*
 	 * When a device_private page is freed, the page->mapping field

mm/migrate.c

@@ -364,7 +364,7 @@ static int expected_page_refs(struct address_space *mapping, struct page *page)
 	 */
 	expected_count += is_device_private_page(page);
 	if (mapping)
-		expected_count += thp_nr_pages(page) + page_has_private(page);
+		expected_count += compound_nr(page) + page_has_private(page);
 
 	return expected_count;
 }
@@ -377,74 +377,75 @@ static int expected_page_refs(struct address_space *mapping, struct page *page)
  * 2 for pages with a mapping
  * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
  */
-int migrate_page_move_mapping(struct address_space *mapping,
+int folio_migrate_mapping(struct address_space *mapping,
-		struct page *newpage, struct page *page, int extra_count)
+		struct folio *newfolio, struct folio *folio, int extra_count)
 {
-	XA_STATE(xas, &mapping->i_pages, page_index(page));
+	XA_STATE(xas, &mapping->i_pages, folio_index(folio));
 	struct zone *oldzone, *newzone;
 	int dirty;
-	int expected_count = expected_page_refs(mapping, page) + extra_count;
+	int expected_count = expected_page_refs(mapping, &folio->page) + extra_count;
-	int nr = thp_nr_pages(page);
+	long nr = folio_nr_pages(folio);
 
 	if (!mapping) {
 		/* Anonymous page without mapping */
-		if (page_count(page) != expected_count)
+		if (folio_ref_count(folio) != expected_count)
 			return -EAGAIN;
 
 		/* No turning back from here */
-		newpage->index = page->index;
+		newfolio->index = folio->index;
-		newpage->mapping = page->mapping;
+		newfolio->mapping = folio->mapping;
-		if (PageSwapBacked(page))
+		if (folio_test_swapbacked(folio))
-			__SetPageSwapBacked(newpage);
+			__folio_set_swapbacked(newfolio);
 
 		return MIGRATEPAGE_SUCCESS;
 	}
 
-	oldzone = page_zone(page);
+	oldzone = folio_zone(folio);
-	newzone = page_zone(newpage);
+	newzone = folio_zone(newfolio);
 
 	xas_lock_irq(&xas);
-	if (page_count(page) != expected_count || xas_load(&xas) != page) {
+	if (folio_ref_count(folio) != expected_count ||
+	    xas_load(&xas) != folio) {
 		xas_unlock_irq(&xas);
 		return -EAGAIN;
 	}
 
-	if (!page_ref_freeze(page, expected_count)) {
+	if (!folio_ref_freeze(folio, expected_count)) {
 		xas_unlock_irq(&xas);
 		return -EAGAIN;
 	}
 
 	/*
-	 * Now we know that no one else is looking at the page:
+	 * Now we know that no one else is looking at the folio:
 	 * no turning back from here.
 	 */
-	newpage->index = page->index;
+	newfolio->index = folio->index;
-	newpage->mapping = page->mapping;
+	newfolio->mapping = folio->mapping;
-	page_ref_add(newpage, nr); /* add cache reference */
+	folio_ref_add(newfolio, nr); /* add cache reference */
-	if (PageSwapBacked(page)) {
+	if (folio_test_swapbacked(folio)) {
-		__SetPageSwapBacked(newpage);
+		__folio_set_swapbacked(newfolio);
-		if (PageSwapCache(page)) {
+		if (folio_test_swapcache(folio)) {
-			SetPageSwapCache(newpage);
+			folio_set_swapcache(newfolio);
-			set_page_private(newpage, page_private(page));
+			newfolio->private = folio_get_private(folio);
 		}
 	} else {
-		VM_BUG_ON_PAGE(PageSwapCache(page), page);
+		VM_BUG_ON_FOLIO(folio_test_swapcache(folio), folio);
 	}
 
 	/* Move dirty while page refs frozen and newpage not yet exposed */
-	dirty = PageDirty(page);
+	dirty = folio_test_dirty(folio);
 	if (dirty) {
-		ClearPageDirty(page);
+		folio_clear_dirty(folio);
-		SetPageDirty(newpage);
+		folio_set_dirty(newfolio);
 	}
 
-	xas_store(&xas, newpage);
+	xas_store(&xas, newfolio);
-	if (PageTransHuge(page)) {
+	if (nr > 1) {
 		int i;
 
 		for (i = 1; i < nr; i++) {
 			xas_next(&xas);
-			xas_store(&xas, newpage);
+			xas_store(&xas, newfolio);
 		}
 	}
 
@@ -453,7 +454,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	 * to one less reference.
 	 * We know this isn't the last reference.
 	 */
-	page_ref_unfreeze(page, expected_count - nr);
+	folio_ref_unfreeze(folio, expected_count - nr);
 
 	xas_unlock(&xas);
 	/* Leave irq disabled to prevent preemption while updating stats */
@@ -472,18 +473,18 @@ int migrate_page_move_mapping(struct address_space *mapping,
 		struct lruvec *old_lruvec, *new_lruvec;
 		struct mem_cgroup *memcg;
 
-		memcg = page_memcg(page);
+		memcg = folio_memcg(folio);
 		old_lruvec = mem_cgroup_lruvec(memcg, oldzone->zone_pgdat);
 		new_lruvec = mem_cgroup_lruvec(memcg, newzone->zone_pgdat);
 
 		__mod_lruvec_state(old_lruvec, NR_FILE_PAGES, -nr);
 		__mod_lruvec_state(new_lruvec, NR_FILE_PAGES, nr);
-		if (PageSwapBacked(page) && !PageSwapCache(page)) {
+		if (folio_test_swapbacked(folio) && !folio_test_swapcache(folio)) {
 			__mod_lruvec_state(old_lruvec, NR_SHMEM, -nr);
 			__mod_lruvec_state(new_lruvec, NR_SHMEM, nr);
 		}
 #ifdef CONFIG_SWAP
-		if (PageSwapCache(page)) {
+		if (folio_test_swapcache(folio)) {
 			__mod_lruvec_state(old_lruvec, NR_SWAPCACHE, -nr);
 			__mod_lruvec_state(new_lruvec, NR_SWAPCACHE, nr);
 		}
@@ -499,11 +500,11 @@ int migrate_page_move_mapping(struct address_space *mapping,
 
 	return MIGRATEPAGE_SUCCESS;
 }
-EXPORT_SYMBOL(migrate_page_move_mapping);
+EXPORT_SYMBOL(folio_migrate_mapping);
 
 /*
  * The expected number of remaining references is the same as that
- * of migrate_page_move_mapping().
+ * of folio_migrate_mapping().
  */
 int migrate_huge_page_move_mapping(struct address_space *mapping,
 				   struct page *newpage, struct page *page)
@@ -538,91 +539,87 @@ int migrate_huge_page_move_mapping(struct address_space *mapping,
 }
 
 /*
- * Copy the page to its new location
+ * Copy the flags and some other ancillary information
  */
-void migrate_page_states(struct page *newpage, struct page *page)
+void folio_migrate_flags(struct folio *newfolio, struct folio *folio)
 {
 	int cpupid;
 
-	if (PageError(page))
+	if (folio_test_error(folio))
-		SetPageError(newpage);
+		folio_set_error(newfolio);
-	if (PageReferenced(page))
+	if (folio_test_referenced(folio))
-		SetPageReferenced(newpage);
+		folio_set_referenced(newfolio);
-	if (PageUptodate(page))
+	if (folio_test_uptodate(folio))
-		SetPageUptodate(newpage);
+		folio_mark_uptodate(newfolio);
-	if (TestClearPageActive(page)) {
+	if (folio_test_clear_active(folio)) {
-		VM_BUG_ON_PAGE(PageUnevictable(page), page);
+		VM_BUG_ON_FOLIO(folio_test_unevictable(folio), folio);
-		SetPageActive(newpage);
+		folio_set_active(newfolio);
-	} else if (TestClearPageUnevictable(page))
+	} else if (folio_test_clear_unevictable(folio))
-		SetPageUnevictable(newpage);
+		folio_set_unevictable(newfolio);
-	if (PageWorkingset(page))
+	if (folio_test_workingset(folio))
-		SetPageWorkingset(newpage);
+		folio_set_workingset(newfolio);
-	if (PageChecked(page))
+	if (folio_test_checked(folio))
-		SetPageChecked(newpage);
+		folio_set_checked(newfolio);
-	if (PageMappedToDisk(page))
+	if (folio_test_mappedtodisk(folio))
-		SetPageMappedToDisk(newpage);
+		folio_set_mappedtodisk(newfolio);
 
-	/* Move dirty on pages not done by migrate_page_move_mapping() */
+	/* Move dirty on pages not done by folio_migrate_mapping() */
-	if (PageDirty(page))
+	if (folio_test_dirty(folio))
-		SetPageDirty(newpage);
+		folio_set_dirty(newfolio);
 
-	if (page_is_young(page))
+	if (folio_test_young(folio))
-		set_page_young(newpage);
+		folio_set_young(newfolio);
-	if (page_is_idle(page))
+	if (folio_test_idle(folio))
-		set_page_idle(newpage);
+		folio_set_idle(newfolio);
 
 	/*
 	 * Copy NUMA information to the new page, to prevent over-eager
 	 * future migrations of this same page.
 	 */
-	cpupid = page_cpupid_xchg_last(page, -1);
+	cpupid = page_cpupid_xchg_last(&folio->page, -1);
-	page_cpupid_xchg_last(newpage, cpupid);
+	page_cpupid_xchg_last(&newfolio->page, cpupid);
 
-	ksm_migrate_page(newpage, page);
+	folio_migrate_ksm(newfolio, folio);
 	/*
 	 * Please do not reorder this without considering how mm/ksm.c's
 	 * get_ksm_page() depends upon ksm_migrate_page() and PageSwapCache().
 	 */
-	if (PageSwapCache(page))
+	if (folio_test_swapcache(folio))
-		ClearPageSwapCache(page);
+		folio_clear_swapcache(folio);
-	ClearPagePrivate(page);
+	folio_clear_private(folio);
 
 	/* page->private contains hugetlb specific flags */
-	if (!PageHuge(page))
+	if (!folio_test_hugetlb(folio))
-		set_page_private(page, 0);
+		folio->private = NULL;
 
 	/*
 	 * If any waiters have accumulated on the new page then
 	 * wake them up.
 	 */
-	if (PageWriteback(newpage))
+	if (folio_test_writeback(newfolio))
-		end_page_writeback(newpage);
+		folio_end_writeback(newfolio);
 
 	/*
 	 * PG_readahead shares the same bit with PG_reclaim.  The above
 	 * end_page_writeback() may clear PG_readahead mistakenly, so set the
 	 * bit after that.
 	 */
-	if (PageReadahead(page))
+	if (folio_test_readahead(folio))
-		SetPageReadahead(newpage);
+		folio_set_readahead(newfolio);
 
-	copy_page_owner(page, newpage);
+	folio_copy_owner(newfolio, folio);
 
-	if (!PageHuge(page))
+	if (!folio_test_hugetlb(folio))
-		mem_cgroup_migrate(page, newpage);
+		mem_cgroup_migrate(folio, newfolio);
 }
-EXPORT_SYMBOL(migrate_page_states);
+EXPORT_SYMBOL(folio_migrate_flags);
 
-void migrate_page_copy(struct page *newpage, struct page *page)
+void folio_migrate_copy(struct folio *newfolio, struct folio *folio)
 {
-	if (PageHuge(page) || PageTransHuge(page))
+	folio_copy(newfolio, folio);
-		copy_huge_page(newpage, page);
+	folio_migrate_flags(newfolio, folio);
-	else
-		copy_highpage(newpage, page);
-
-	migrate_page_states(newpage, page);
 }
-EXPORT_SYMBOL(migrate_page_copy);
+EXPORT_SYMBOL(folio_migrate_copy);
 
 /************************************************************
  *                    Migration functions
@@ -638,19 +635,21 @@ int migrate_page(struct address_space *mapping,
 		struct page *newpage, struct page *page,
 		enum migrate_mode mode)
 {
+	struct folio *newfolio = page_folio(newpage);
+	struct folio *folio = page_folio(page);
 	int rc;
 
-	BUG_ON(PageWriteback(page));	/* Writeback must be complete */
+	BUG_ON(folio_test_writeback(folio));	/* Writeback must be complete */
 
-	rc = migrate_page_move_mapping(mapping, newpage, page, 0);
+	rc = folio_migrate_mapping(mapping, newfolio, folio, 0);
 
 	if (rc != MIGRATEPAGE_SUCCESS)
 		return rc;
 
 	if (mode != MIGRATE_SYNC_NO_COPY)
-		migrate_page_copy(newpage, page);
+		folio_migrate_copy(newfolio, folio);
 	else
-		migrate_page_states(newpage, page);
+		folio_migrate_flags(newfolio, folio);
 	return MIGRATEPAGE_SUCCESS;
 }
 EXPORT_SYMBOL(migrate_page);
@@ -2468,7 +2467,7 @@ static void migrate_vma_collect(struct migrate_vma *migrate)
  * @page: struct page to check
  *
  * Pinned pages cannot be migrated. This is the same test as in
- * migrate_page_move_mapping(), except that here we allow migration of a
+ * folio_migrate_mapping(), except that here we allow migration of a
  * ZONE_DEVICE page.
  */
 static bool migrate_vma_check_page(struct page *page)
@@ -2846,7 +2845,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 
 	if (unlikely(anon_vma_prepare(vma)))
 		goto abort;
-	if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL))
+	if (mem_cgroup_charge(page_folio(page), vma->vm_mm, GFP_KERNEL))
 		goto abort;
 
 	/*

mm/mlock.c

@@ -271,6 +271,7 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
 	/* Phase 1: page isolation */
 	for (i = 0; i < nr; i++) {
 		struct page *page = pvec->pages[i];
+		struct folio *folio = page_folio(page);
 
 		if (TestClearPageMlocked(page)) {
 			/*
@@ -278,7 +279,7 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
 			 * so we can spare the get_page() here.
 			 */
 			if (TestClearPageLRU(page)) {
-				lruvec = relock_page_lruvec_irq(page, lruvec);
+				lruvec = folio_lruvec_relock_irq(folio, lruvec);
 				del_page_from_lru_list(page, lruvec);
 				continue;
 			} else

mm/page-writeback.c

@@ -562,12 +562,12 @@ static unsigned long wp_next_time(unsigned long cur_time)
 	return cur_time;
 }
 
-static void wb_domain_writeout_inc(struct wb_domain *dom,
+static void wb_domain_writeout_add(struct wb_domain *dom,
 				   struct fprop_local_percpu *completions,
-				   unsigned int max_prop_frac)
+				   unsigned int max_prop_frac, long nr)
 {
-	__fprop_inc_percpu_max(&dom->completions, completions,
+	__fprop_add_percpu_max(&dom->completions, completions,
-			       max_prop_frac);
+			       max_prop_frac, nr);
 	/* First event after period switching was turned off? */
 	if (unlikely(!dom->period_time)) {
 		/*
@@ -583,20 +583,20 @@ static void wb_domain_writeout_inc(struct wb_domain *dom,
 
 /*
  * Increment @wb's writeout completion count and the global writeout
- * completion count. Called from test_clear_page_writeback().
+ * completion count. Called from __folio_end_writeback().
  */
-static inline void __wb_writeout_inc(struct bdi_writeback *wb)
+static inline void __wb_writeout_add(struct bdi_writeback *wb, long nr)
 {
 	struct wb_domain *cgdom;
 
-	inc_wb_stat(wb, WB_WRITTEN);
+	wb_stat_mod(wb, WB_WRITTEN, nr);
-	wb_domain_writeout_inc(&global_wb_domain, &wb->completions,
+	wb_domain_writeout_add(&global_wb_domain, &wb->completions,
-			       wb->bdi->max_prop_frac);
+			       wb->bdi->max_prop_frac, nr);
 
 	cgdom = mem_cgroup_wb_domain(wb);
 	if (cgdom)
-		wb_domain_writeout_inc(cgdom, wb_memcg_completions(wb),
+		wb_domain_writeout_add(cgdom, wb_memcg_completions(wb),
-				       wb->bdi->max_prop_frac);
+				       wb->bdi->max_prop_frac, nr);
 }
 
 void wb_writeout_inc(struct bdi_writeback *wb)
@@ -604,7 +604,7 @@ void wb_writeout_inc(struct bdi_writeback *wb)
 	unsigned long flags;
 
 	local_irq_save(flags);
-	__wb_writeout_inc(wb);
+	__wb_writeout_add(wb, 1);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(wb_writeout_inc);
@@ -1084,7 +1084,7 @@ static void wb_update_write_bandwidth(struct bdi_writeback *wb,
 	 * write_bandwidth = ---------------------------------------------------
 	 *                                          period
 	 *
-	 * @written may have decreased due to account_page_redirty().
+	 * @written may have decreased due to folio_account_redirty().
 	 * Avoid underflowing @bw calculation.
 	 */
 	bw = written - min(written, wb->written_stamp);
@@ -2381,44 +2381,44 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
 }
 
 /**
- * write_one_page - write out a single page and wait on I/O
+ * folio_write_one - write out a single folio and wait on I/O.
- * @page: the page to write
+ * @folio: The folio to write.
  *
- * The page must be locked by the caller and will be unlocked upon return.
+ * The folio must be locked by the caller and will be unlocked upon return.
  *
  * Note that the mapping's AS_EIO/AS_ENOSPC flags will be cleared when this
  * function returns.
  *
  * Return: %0 on success, negative error code otherwise
  */
-int write_one_page(struct page *page)
+int folio_write_one(struct folio *folio)
 {
-	struct address_space *mapping = page->mapping;
+	struct address_space *mapping = folio->mapping;
 	int ret = 0;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_ALL,
-		.nr_to_write = 1,
+		.nr_to_write = folio_nr_pages(folio),
 	};
 
-	BUG_ON(!PageLocked(page));
+	BUG_ON(!folio_test_locked(folio));
 
-	wait_on_page_writeback(page);
+	folio_wait_writeback(folio);
 
-	if (clear_page_dirty_for_io(page)) {
+	if (folio_clear_dirty_for_io(folio)) {
-		get_page(page);
+		folio_get(folio);
-		ret = mapping->a_ops->writepage(page, &wbc);
+		ret = mapping->a_ops->writepage(&folio->page, &wbc);
 		if (ret == 0)
-			wait_on_page_writeback(page);
+			folio_wait_writeback(folio);
-		put_page(page);
+		folio_put(folio);
 	} else {
-		unlock_page(page);
+		folio_unlock(folio);
 	}
 
 	if (!ret)
 		ret = filemap_check_errors(mapping);
 	return ret;
 }
-EXPORT_SYMBOL(write_one_page);
+EXPORT_SYMBOL(folio_write_one);
 
 /*
  * For address_spaces which do not use buffers nor write back.
@@ -2438,29 +2438,30 @@ EXPORT_SYMBOL(__set_page_dirty_no_writeback);
  *
  * NOTE: This relies on being atomic wrt interrupts.
  */
-static void account_page_dirtied(struct page *page,
+static void folio_account_dirtied(struct folio *folio,
 		struct address_space *mapping)
 {
 	struct inode *inode = mapping->host;
 
-	trace_writeback_dirty_page(page, mapping);
+	trace_writeback_dirty_folio(folio, mapping);
 
 	if (mapping_can_writeback(mapping)) {
 		struct bdi_writeback *wb;
+		long nr = folio_nr_pages(folio);
 
-		inode_attach_wb(inode, page);
+		inode_attach_wb(inode, &folio->page);
 		wb = inode_to_wb(inode);
 
-		__inc_lruvec_page_state(page, NR_FILE_DIRTY);
+		__lruvec_stat_mod_folio(folio, NR_FILE_DIRTY, nr);
-		__inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
+		__zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, nr);
-		__inc_node_page_state(page, NR_DIRTIED);
+		__node_stat_mod_folio(folio, NR_DIRTIED, nr);
-		inc_wb_stat(wb, WB_RECLAIMABLE);
+		wb_stat_mod(wb, WB_RECLAIMABLE, nr);
-		inc_wb_stat(wb, WB_DIRTIED);
+		wb_stat_mod(wb, WB_DIRTIED, nr);
-		task_io_account_write(PAGE_SIZE);
+		task_io_account_write(nr * PAGE_SIZE);
-		current->nr_dirtied++;
+		current->nr_dirtied += nr;
-		__this_cpu_inc(bdp_ratelimits);
+		__this_cpu_add(bdp_ratelimits, nr);
 
-		mem_cgroup_track_foreign_dirty(page, wb);
+		mem_cgroup_track_foreign_dirty(folio, wb);
 	}
 }
 
@@ -2469,130 +2470,152 @@ static void account_page_dirtied(struct page *page,
  *
  * Caller must hold lock_page_memcg().
  */
-void account_page_cleaned(struct page *page, struct address_space *mapping,
+void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
 			  struct bdi_writeback *wb)
 {
 	if (mapping_can_writeback(mapping)) {
-		dec_lruvec_page_state(page, NR_FILE_DIRTY);
+		long nr = folio_nr_pages(folio);
-		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
+		lruvec_stat_mod_folio(folio, NR_FILE_DIRTY, -nr);
-		dec_wb_stat(wb, WB_RECLAIMABLE);
+		zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
-		task_io_account_cancelled_write(PAGE_SIZE);
+		wb_stat_mod(wb, WB_RECLAIMABLE, -nr);
+		task_io_account_cancelled_write(nr * PAGE_SIZE);
 	}
 }
 
 /*
- * Mark the page dirty, and set it dirty in the page cache, and mark the inode
+ * Mark the folio dirty, and set it dirty in the page cache, and mark
- * dirty.
+ * the inode dirty.
  *
- * If warn is true, then emit a warning if the page is not uptodate and has
+ * If warn is true, then emit a warning if the folio is not uptodate and has
  * not been truncated.
  *
  * The caller must hold lock_page_memcg().
  */
-void __set_page_dirty(struct page *page, struct address_space *mapping,
+void __folio_mark_dirty(struct folio *folio, struct address_space *mapping,
 			     int warn)
 {
 	unsigned long flags;
 
 	xa_lock_irqsave(&mapping->i_pages, flags);
-	if (page->mapping) {	/* Race with truncate? */
+	if (folio->mapping) {	/* Race with truncate? */
-		WARN_ON_ONCE(warn && !PageUptodate(page));
+		WARN_ON_ONCE(warn && !folio_test_uptodate(folio));
-		account_page_dirtied(page, mapping);
+		folio_account_dirtied(folio, mapping);
-		__xa_set_mark(&mapping->i_pages, page_index(page),
+		__xa_set_mark(&mapping->i_pages, folio_index(folio),
 				PAGECACHE_TAG_DIRTY);
 	}
 	xa_unlock_irqrestore(&mapping->i_pages, flags);
 }
 
-/*
+/**
- * For address_spaces which do not use buffers.  Just tag the page as dirty in
+ * filemap_dirty_folio - Mark a folio dirty for filesystems which do not use buffer_heads.
- * the xarray.
+ * @mapping: Address space this folio belongs to.
+ * @folio: Folio to be marked as dirty.
  *
- * This is also used when a single buffer is being dirtied: we want to set the
+ * Filesystems which do not use buffer heads should call this function
- * page dirty in that case, but not all the buffers.  This is a "bottom-up"
+ * from their set_page_dirty address space operation.  It ignores the
- * dirtying, whereas __set_page_dirty_buffers() is a "top-down" dirtying.
+ * contents of folio_get_private(), so if the filesystem marks individual
+ * blocks as dirty, the filesystem should handle that itself.
  *
- * The caller must ensure this doesn't race with truncation.  Most will simply
+ * This is also sometimes used by filesystems which use buffer_heads when
- * hold the page lock, but e.g. zap_pte_range() calls with the page mapped and
+ * a single buffer is being dirtied: we want to set the folio dirty in
- * the pte lock held, which also locks out truncation.
+ * that case, but not all the buffers.  This is a "bottom-up" dirtying,
+ * whereas __set_page_dirty_buffers() is a "top-down" dirtying.
+ *
+ * The caller must ensure this doesn't race with truncation.  Most will
+ * simply hold the folio lock, but e.g. zap_pte_range() calls with the
+ * folio mapped and the pte lock held, which also locks out truncation.
  */
-int __set_page_dirty_nobuffers(struct page *page)
+bool filemap_dirty_folio(struct address_space *mapping, struct folio *folio)
 {
-	lock_page_memcg(page);
+	folio_memcg_lock(folio);
-	if (!TestSetPageDirty(page)) {
+	if (folio_test_set_dirty(folio)) {
-		struct address_space *mapping = page_mapping(page);
+		folio_memcg_unlock(folio);
-
+		return false;
-		if (!mapping) {
-			unlock_page_memcg(page);
-			return 1;
-		}
-		__set_page_dirty(page, mapping, !PagePrivate(page));
-		unlock_page_memcg(page);
-
-		if (mapping->host) {
-			/* !PageAnon && !swapper_space */
-			__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-		}
-		return 1;
 	}
-	unlock_page_memcg(page);
-	return 0;
-}
-EXPORT_SYMBOL(__set_page_dirty_nobuffers);
 
-/*
+	__folio_mark_dirty(folio, mapping, !folio_test_private(folio));
- * Call this whenever redirtying a page, to de-account the dirty counters
+	folio_memcg_unlock(folio);
- * (NR_DIRTIED, WB_DIRTIED, tsk->nr_dirtied), so that they match the written
+
- * counters (NR_WRITTEN, WB_WRITTEN) in long term. The mismatches will lead to
+	if (mapping->host) {
- * systematic errors in balanced_dirty_ratelimit and the dirty pages position
+		/* !PageAnon && !swapper_space */
- * control.
+		__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+	}
+	return true;
+}
+EXPORT_SYMBOL(filemap_dirty_folio);
+
+/**
+ * folio_account_redirty - Manually account for redirtying a page.
+ * @folio: The folio which is being redirtied.
+ *
+ * Most filesystems should call folio_redirty_for_writepage() instead
+ * of this fuction.  If your filesystem is doing writeback outside the
+ * context of a writeback_control(), it can call this when redirtying
+ * a folio, to de-account the dirty counters (NR_DIRTIED, WB_DIRTIED,
+ * tsk->nr_dirtied), so that they match the written counters (NR_WRITTEN,
+ * WB_WRITTEN) in long term. The mismatches will lead to systematic errors
+ * in balanced_dirty_ratelimit and the dirty pages position control.
  */
-void account_page_redirty(struct page *page)
+void folio_account_redirty(struct folio *folio)
 {
-	struct address_space *mapping = page->mapping;
+	struct address_space *mapping = folio->mapping;
 
 	if (mapping && mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};
+		long nr = folio_nr_pages(folio);
 
 		wb = unlocked_inode_to_wb_begin(inode, &cookie);
-		current->nr_dirtied--;
+		current->nr_dirtied -= nr;
-		dec_node_page_state(page, NR_DIRTIED);
+		node_stat_mod_folio(folio, NR_DIRTIED, -nr);
-		dec_wb_stat(wb, WB_DIRTIED);
+		wb_stat_mod(wb, WB_DIRTIED, -nr);
 		unlocked_inode_to_wb_end(inode, &cookie);
 	}
 }
-EXPORT_SYMBOL(account_page_redirty);
+EXPORT_SYMBOL(folio_account_redirty);
 
-/*
+/**
- * When a writepage implementation decides that it doesn't want to write this
+ * folio_redirty_for_writepage - Decline to write a dirty folio.
- * page for some reason, it should redirty the locked page via
+ * @wbc: The writeback control.
- * redirty_page_for_writepage() and it should then unlock the page and return 0
+ * @folio: The folio.
+ *
+ * When a writepage implementation decides that it doesn't want to write
+ * @folio for some reason, it should call this function, unlock @folio and
+ * return 0.
+ *
+ * Return: True if we redirtied the folio.  False if someone else dirtied
+ * it first.
  */
-int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
+bool folio_redirty_for_writepage(struct writeback_control *wbc,
+		struct folio *folio)
 {
-	int ret;
+	bool ret;
+	long nr = folio_nr_pages(folio);
+
+	wbc->pages_skipped += nr;
+	ret = filemap_dirty_folio(folio->mapping, folio);
+	folio_account_redirty(folio);
 
-	wbc->pages_skipped++;
-	ret = __set_page_dirty_nobuffers(page);
-	account_page_redirty(page);
 	return ret;
 }
-EXPORT_SYMBOL(redirty_page_for_writepage);
+EXPORT_SYMBOL(folio_redirty_for_writepage);
 
-/*
+/**
- * Dirty a page.
+ * folio_mark_dirty - Mark a folio as being modified.
+ * @folio: The folio.
  *
- * For pages with a mapping this should be done under the page lock for the
+ * For folios with a mapping this should be done under the page lock
- * benefit of asynchronous memory errors who prefer a consistent dirty state.
+ * for the benefit of asynchronous memory errors who prefer a consistent
- * This rule can be broken in some special cases, but should be better not to.
+ * dirty state. This rule can be broken in some special cases,
+ * but should be better not to.
+ *
+ * Return: True if the folio was newly dirtied, false if it was already dirty.
  */
-int set_page_dirty(struct page *page)
+bool folio_mark_dirty(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
+	struct address_space *mapping = folio_mapping(folio);
 
-	page = compound_head(page);
 	if (likely(mapping)) {
 		/*
 		 * readahead/lru_deactivate_page could remain
@@ -2604,17 +2627,17 @@ int set_page_dirty(struct page *page)
 		 * it will confuse readahead and make it restart the size rampup
 		 * process. But it's a trivial problem.
 		 */
-		if (PageReclaim(page))
+		if (folio_test_reclaim(folio))
-			ClearPageReclaim(page);
+			folio_clear_reclaim(folio);
-		return mapping->a_ops->set_page_dirty(page);
+		return mapping->a_ops->set_page_dirty(&folio->page);
 	}
-	if (!PageDirty(page)) {
+	if (!folio_test_dirty(folio)) {
-		if (!TestSetPageDirty(page))
+		if (!folio_test_set_dirty(folio))
-			return 1;
+			return true;
 	}
-	return 0;
+	return false;
 }
-EXPORT_SYMBOL(set_page_dirty);
+EXPORT_SYMBOL(folio_mark_dirty);
 
 /*
  * set_page_dirty() is racy if the caller has no reference against
@@ -2650,49 +2673,49 @@ EXPORT_SYMBOL(set_page_dirty_lock);
  * page without actually doing it through the VM. Can you say "ext3 is
  * horribly ugly"? Thought you could.
  */
-void __cancel_dirty_page(struct page *page)
+void __folio_cancel_dirty(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
+	struct address_space *mapping = folio_mapping(folio);
 
 	if (mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};
 
-		lock_page_memcg(page);
+		folio_memcg_lock(folio);
 		wb = unlocked_inode_to_wb_begin(inode, &cookie);
 
-		if (TestClearPageDirty(page))
+		if (folio_test_clear_dirty(folio))
-			account_page_cleaned(page, mapping, wb);
+			folio_account_cleaned(folio, mapping, wb);
 
 		unlocked_inode_to_wb_end(inode, &cookie);
-		unlock_page_memcg(page);
+		folio_memcg_unlock(folio);
 	} else {
-		ClearPageDirty(page);
+		folio_clear_dirty(folio);
 	}
 }
-EXPORT_SYMBOL(__cancel_dirty_page);
+EXPORT_SYMBOL(__folio_cancel_dirty);
 
 /*
- * Clear a page's dirty flag, while caring for dirty memory accounting.
+ * Clear a folio's dirty flag, while caring for dirty memory accounting.
- * Returns true if the page was previously dirty.
+ * Returns true if the folio was previously dirty.
  *
- * This is for preparing to put the page under writeout.  We leave the page
+ * This is for preparing to put the folio under writeout.  We leave
- * tagged as dirty in the xarray so that a concurrent write-for-sync
+ * the folio tagged as dirty in the xarray so that a concurrent
- * can discover it via a PAGECACHE_TAG_DIRTY walk.  The ->writepage
+ * write-for-sync can discover it via a PAGECACHE_TAG_DIRTY walk.
- * implementation will run either set_page_writeback() or set_page_dirty(),
+ * The ->writepage implementation will run either folio_start_writeback()
- * at which stage we bring the page's dirty flag and xarray dirty tag
+ * or folio_mark_dirty(), at which stage we bring the folio's dirty flag
- * back into sync.
+ * and xarray dirty tag back into sync.
  *
- * This incoherency between the page's dirty flag and xarray tag is
+ * This incoherency between the folio's dirty flag and xarray tag is
- * unfortunate, but it only exists while the page is locked.
+ * unfortunate, but it only exists while the folio is locked.
  */
-int clear_page_dirty_for_io(struct page *page)
+bool folio_clear_dirty_for_io(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
+	struct address_space *mapping = folio_mapping(folio);
-	int ret = 0;
+	bool ret = false;
 
-	VM_BUG_ON_PAGE(!PageLocked(page), page);
+	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
 
 	if (mapping && mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
@@ -2705,48 +2728,49 @@ int clear_page_dirty_for_io(struct page *page)
 		 * We use this sequence to make sure that
 		 *  (a) we account for dirty stats properly
 		 *  (b) we tell the low-level filesystem to
-		 *      mark the whole page dirty if it was
+		 *      mark the whole folio dirty if it was
 		 *      dirty in a pagetable. Only to then
-		 *  (c) clean the page again and return 1 to
+		 *  (c) clean the folio again and return 1 to
 		 *      cause the writeback.
 		 *
 		 * This way we avoid all nasty races with the
 		 * dirty bit in multiple places and clearing
 		 * them concurrently from different threads.
 		 *
-		 * Note! Normally the "set_page_dirty(page)"
+		 * Note! Normally the "folio_mark_dirty(folio)"
 		 * has no effect on the actual dirty bit - since
 		 * that will already usually be set. But we
 		 * need the side effects, and it can help us
 		 * avoid races.
 		 *
-		 * We basically use the page "master dirty bit"
+		 * We basically use the folio "master dirty bit"
 		 * as a serialization point for all the different
 		 * threads doing their things.
 		 */
-		if (page_mkclean(page))
+		if (folio_mkclean(folio))
-			set_page_dirty(page);
+			folio_mark_dirty(folio);
 		/*
 		 * We carefully synchronise fault handlers against
-		 * installing a dirty pte and marking the page dirty
+		 * installing a dirty pte and marking the folio dirty
 		 * at this point.  We do this by having them hold the
-		 * page lock while dirtying the page, and pages are
+		 * page lock while dirtying the folio, and folios are
 		 * always locked coming in here, so we get the desired
 		 * exclusion.
 		 */
 		wb = unlocked_inode_to_wb_begin(inode, &cookie);
-		if (TestClearPageDirty(page)) {
+		if (folio_test_clear_dirty(folio)) {
-			dec_lruvec_page_state(page, NR_FILE_DIRTY);
+			long nr = folio_nr_pages(folio);
-			dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
+			lruvec_stat_mod_folio(folio, NR_FILE_DIRTY, -nr);
-			dec_wb_stat(wb, WB_RECLAIMABLE);
+			zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
-			ret = 1;
+			wb_stat_mod(wb, WB_RECLAIMABLE, -nr);
+			ret = true;
 		}
 		unlocked_inode_to_wb_end(inode, &cookie);
 		return ret;
 	}
-	return TestClearPageDirty(page);
+	return folio_test_clear_dirty(folio);
 }
-EXPORT_SYMBOL(clear_page_dirty_for_io);
+EXPORT_SYMBOL(folio_clear_dirty_for_io);
 
 static void wb_inode_writeback_start(struct bdi_writeback *wb)
 {
@@ -2766,27 +2790,28 @@ static void wb_inode_writeback_end(struct bdi_writeback *wb)
 	queue_delayed_work(bdi_wq, &wb->bw_dwork, BANDWIDTH_INTERVAL);
 }
 
-int test_clear_page_writeback(struct page *page)
+bool __folio_end_writeback(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
+	long nr = folio_nr_pages(folio);
-	int ret;
+	struct address_space *mapping = folio_mapping(folio);
+	bool ret;
 
-	lock_page_memcg(page);
+	folio_memcg_lock(folio);
 	if (mapping && mapping_use_writeback_tags(mapping)) {
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
 		unsigned long flags;
 
 		xa_lock_irqsave(&mapping->i_pages, flags);
-		ret = TestClearPageWriteback(page);
+		ret = folio_test_clear_writeback(folio);
 		if (ret) {
-			__xa_clear_mark(&mapping->i_pages, page_index(page),
+			__xa_clear_mark(&mapping->i_pages, folio_index(folio),
 						PAGECACHE_TAG_WRITEBACK);
 			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
 				struct bdi_writeback *wb = inode_to_wb(inode);
 
-				dec_wb_stat(wb, WB_WRITEBACK);
+				wb_stat_mod(wb, WB_WRITEBACK, -nr);
-				__wb_writeout_inc(wb);
+				__wb_writeout_add(wb, nr);
 				if (!mapping_tagged(mapping,
 						    PAGECACHE_TAG_WRITEBACK))
 					wb_inode_writeback_end(wb);
@@ -2799,32 +2824,34 @@ int test_clear_page_writeback(struct page *page)
 
 		xa_unlock_irqrestore(&mapping->i_pages, flags);
 	} else {
-		ret = TestClearPageWriteback(page);
+		ret = folio_test_clear_writeback(folio);
 	}
 	if (ret) {
-		dec_lruvec_page_state(page, NR_WRITEBACK);
+		lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
-		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
+		zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
-		inc_node_page_state(page, NR_WRITTEN);
+		node_stat_mod_folio(folio, NR_WRITTEN, nr);
 	}
-	unlock_page_memcg(page);
+	folio_memcg_unlock(folio);
 	return ret;
 }
 
-int __test_set_page_writeback(struct page *page, bool keep_write)
+bool __folio_start_writeback(struct folio *folio, bool keep_write)
 {
-	struct address_space *mapping = page_mapping(page);
+	long nr = folio_nr_pages(folio);
-	int ret, access_ret;
+	struct address_space *mapping = folio_mapping(folio);
+	bool ret;
+	int access_ret;
 
-	lock_page_memcg(page);
+	folio_memcg_lock(folio);
 	if (mapping && mapping_use_writeback_tags(mapping)) {
-		XA_STATE(xas, &mapping->i_pages, page_index(page));
+		XA_STATE(xas, &mapping->i_pages, folio_index(folio));
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
 		unsigned long flags;
 
 		xas_lock_irqsave(&xas, flags);
 		xas_load(&xas);
-		ret = TestSetPageWriteback(page);
+		ret = folio_test_set_writeback(folio);
 		if (!ret) {
 			bool on_wblist;
 
@@ -2835,84 +2862,105 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
 			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
 				struct bdi_writeback *wb = inode_to_wb(inode);
 
-				inc_wb_stat(wb, WB_WRITEBACK);
+				wb_stat_mod(wb, WB_WRITEBACK, nr);
 				if (!on_wblist)
 					wb_inode_writeback_start(wb);
 			}
 
 			/*
-			 * We can come through here when swapping anonymous
+			 * We can come through here when swapping
-			 * pages, so we don't necessarily have an inode to track
+			 * anonymous folios, so we don't necessarily
-			 * for sync.
+			 * have an inode to track for sync.
 			 */
 			if (mapping->host && !on_wblist)
 				sb_mark_inode_writeback(mapping->host);
 		}
-		if (!PageDirty(page))
+		if (!folio_test_dirty(folio))
 			xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY);
 		if (!keep_write)
 			xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE);
 		xas_unlock_irqrestore(&xas, flags);
 	} else {
-		ret = TestSetPageWriteback(page);
+		ret = folio_test_set_writeback(folio);
 	}
 	if (!ret) {
-		inc_lruvec_page_state(page, NR_WRITEBACK);
+		lruvec_stat_mod_folio(folio, NR_WRITEBACK, nr);
-		inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
+		zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, nr);
 	}
-	unlock_page_memcg(page);
+	folio_memcg_unlock(folio);
-	access_ret = arch_make_page_accessible(page);
+	access_ret = arch_make_folio_accessible(folio);
 	/*
 	 * If writeback has been triggered on a page that cannot be made
 	 * accessible, it is too late to recover here.
 	 */
-	VM_BUG_ON_PAGE(access_ret != 0, page);
+	VM_BUG_ON_FOLIO(access_ret != 0, folio);
 
 	return ret;
-
 }
-EXPORT_SYMBOL(__test_set_page_writeback);
+EXPORT_SYMBOL(__folio_start_writeback);
 
-/*
+/**
- * Wait for a page to complete writeback
+ * folio_wait_writeback - Wait for a folio to finish writeback.
+ * @folio: The folio to wait for.
+ *
+ * If the folio is currently being written back to storage, wait for the
+ * I/O to complete.
+ *
+ * Context: Sleeps.  Must be called in process context and with
+ * no spinlocks held.  Caller should hold a reference on the folio.
+ * If the folio is not locked, writeback may start again after writeback
+ * has finished.
  */
-void wait_on_page_writeback(struct page *page)
+void folio_wait_writeback(struct folio *folio)
 {
-	while (PageWriteback(page)) {
+	while (folio_test_writeback(folio)) {
-		trace_wait_on_page_writeback(page, page_mapping(page));
+		trace_folio_wait_writeback(folio, folio_mapping(folio));
-		wait_on_page_bit(page, PG_writeback);
+		folio_wait_bit(folio, PG_writeback);
 	}
 }
-EXPORT_SYMBOL_GPL(wait_on_page_writeback);
+EXPORT_SYMBOL_GPL(folio_wait_writeback);
 
-/*
+/**
- * Wait for a page to complete writeback.  Returns -EINTR if we get a
+ * folio_wait_writeback_killable - Wait for a folio to finish writeback.
- * fatal signal while waiting.
+ * @folio: The folio to wait for.
+ *
+ * If the folio is currently being written back to storage, wait for the
+ * I/O to complete or a fatal signal to arrive.
+ *
+ * Context: Sleeps.  Must be called in process context and with
+ * no spinlocks held.  Caller should hold a reference on the folio.
+ * If the folio is not locked, writeback may start again after writeback
+ * has finished.
+ * Return: 0 on success, -EINTR if we get a fatal signal while waiting.
  */
-int wait_on_page_writeback_killable(struct page *page)
+int folio_wait_writeback_killable(struct folio *folio)
 {
-	while (PageWriteback(page)) {
+	while (folio_test_writeback(folio)) {
-		trace_wait_on_page_writeback(page, page_mapping(page));
+		trace_folio_wait_writeback(folio, folio_mapping(folio));
-		if (wait_on_page_bit_killable(page, PG_writeback))
+		if (folio_wait_bit_killable(folio, PG_writeback))
 			return -EINTR;
 	}
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(wait_on_page_writeback_killable);
+EXPORT_SYMBOL_GPL(folio_wait_writeback_killable);
 
 /**
- * wait_for_stable_page() - wait for writeback to finish, if necessary.
+ * folio_wait_stable() - wait for writeback to finish, if necessary.
- * @page:	The page to wait on.
+ * @folio: The folio to wait on.
  *
- * This function determines if the given page is related to a backing device
+ * This function determines if the given folio is related to a backing
- * that requires page contents to be held stable during writeback.  If so, then
+ * device that requires folio contents to be held stable during writeback.
- * it will wait for any pending writeback to complete.
+ * If so, then it will wait for any pending writeback to complete.
+ *
+ * Context: Sleeps.  Must be called in process context and with
+ * no spinlocks held.  Caller should hold a reference on the folio.
+ * If the folio is not locked, writeback may start again after writeback
+ * has finished.
  */
-void wait_for_stable_page(struct page *page)
+void folio_wait_stable(struct folio *folio)
 {
-	page = thp_head(page);
+	if (folio->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
-	if (page->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
+		folio_wait_writeback(folio);
-		wait_on_page_writeback(page);
 }
-EXPORT_SYMBOL_GPL(wait_for_stable_page);
+EXPORT_SYMBOL_GPL(folio_wait_stable);

mm/page_alloc.c

@@ -724,7 +724,7 @@ static inline void free_the_page(struct page *page, unsigned int order)
 
 void free_compound_page(struct page *page)
 {
-	mem_cgroup_uncharge(page);
+	mem_cgroup_uncharge(page_folio(page));
 	free_the_page(page, compound_order(page));
 }
 
@@ -5406,6 +5406,18 @@ out:
 }
 EXPORT_SYMBOL(__alloc_pages);
 
+struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
+		nodemask_t *nodemask)
+{
+	struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
+			preferred_nid, nodemask);
+
+	if (page && order > 1)
+		prep_transhuge_page(page);
+	return (struct folio *)page;
+}
+EXPORT_SYMBOL(__folio_alloc);
+
 /*
  * Common helper functions. Never use with __GFP_HIGHMEM because the returned
  * address cannot represent highmem pages. Use alloc_pages and then kmap if

mm/page_io.c

@@ -38,7 +38,7 @@ void end_swap_bio_write(struct bio *bio)
 		 * Also print a dire warning that things will go BAD (tm)
 		 * very quickly.
 		 *
-		 * Also clear PG_reclaim to avoid rotate_reclaimable_page()
+		 * Also clear PG_reclaim to avoid folio_rotate_reclaimable()
 		 */
 		set_page_dirty(page);
 		pr_alert_ratelimited("Write-error on swap-device (%u:%u:%llu)\n",
@@ -317,7 +317,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
 			 * temporary failure if the system has limited
 			 * memory for allocating transmit buffers.
 			 * Mark the page dirty and avoid
-			 * rotate_reclaimable_page but rate-limit the
+			 * folio_rotate_reclaimable but rate-limit the
 			 * messages but do not flag PageError like
 			 * the normal direct-to-bio case as it could
 			 * be temporary.

mm/page_owner.c

@@ -210,10 +210,10 @@ void __split_page_owner(struct page *page, unsigned int nr)
 	}
 }
 
-void __copy_page_owner(struct page *oldpage, struct page *newpage)
+void __folio_copy_owner(struct folio *newfolio, struct folio *old)
 {
-	struct page_ext *old_ext = lookup_page_ext(oldpage);
+	struct page_ext *old_ext = lookup_page_ext(&old->page);
-	struct page_ext *new_ext = lookup_page_ext(newpage);
+	struct page_ext *new_ext = lookup_page_ext(&newfolio->page);
 	struct page_owner *old_page_owner, *new_page_owner;
 
 	if (unlikely(!old_ext || !new_ext))
@@ -231,11 +231,11 @@ void __copy_page_owner(struct page *oldpage, struct page *newpage)
 	new_page_owner->free_ts_nsec = old_page_owner->ts_nsec;
 
 	/*
-	 * We don't clear the bit on the oldpage as it's going to be freed
+	 * We don't clear the bit on the old folio as it's going to be freed
 	 * after migration. Until then, the info can be useful in case of
 	 * a bug, and the overall stats will be off a bit only temporarily.
 	 * Also, migrate_misplaced_transhuge_page() can still fail the
-	 * migration and then we want the oldpage to retain the info. But
+	 * migration and then we want the old folio to retain the info. But
 	 * in that case we also don't need to explicitly clear the info from
 	 * the new page, which will be freed.
 	 */

mm/rmap.c

@@ -34,7 +34,7 @@
  *                   mapping->private_lock (in __set_page_dirty_buffers)
  *                     lock_page_memcg move_lock (in __set_page_dirty_buffers)
  *                       i_pages lock (widely used)
- *                         lruvec->lru_lock (in lock_page_lruvec_irq)
+ *                         lruvec->lru_lock (in folio_lruvec_lock_irq)
  *                   inode->i_lock (in set_page_dirty's __mark_inode_dirty)
  *                   bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)
  *                     sb_lock (within inode_lock in fs/fs-writeback.c)
@@ -981,7 +981,7 @@ static bool invalid_mkclean_vma(struct vm_area_struct *vma, void *arg)
 	return true;
 }
 
-int page_mkclean(struct page *page)
+int folio_mkclean(struct folio *folio)
 {
 	int cleaned = 0;
 	struct address_space *mapping;
@@ -991,20 +991,20 @@ int page_mkclean(struct page *page)
 		.invalid_vma = invalid_mkclean_vma,
 	};
 
-	BUG_ON(!PageLocked(page));
+	BUG_ON(!folio_test_locked(folio));
 
-	if (!page_mapped(page))
+	if (!folio_mapped(folio))
 		return 0;
 
-	mapping = page_mapping(page);
+	mapping = folio_mapping(folio);
 	if (!mapping)
 		return 0;
 
-	rmap_walk(page, &rwc);
+	rmap_walk(&folio->page, &rwc);
 
 	return cleaned;
 }
-EXPORT_SYMBOL_GPL(page_mkclean);
+EXPORT_SYMBOL_GPL(folio_mkclean);
 
 /**
  * page_move_anon_rmap - move a page to our anon_vma

mm/shmem.c

@@ -710,7 +710,7 @@ static int shmem_add_to_page_cache(struct page *page,
 	page->index = index;
 
 	if (!PageSwapCache(page)) {
-		error = mem_cgroup_charge(page, charge_mm, gfp);
+		error = mem_cgroup_charge(page_folio(page), charge_mm, gfp);
 		if (error) {
 			if (PageTransHuge(page)) {
 				count_vm_event(THP_FILE_FALLBACK);
@@ -1637,6 +1637,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
 				struct shmem_inode_info *info, pgoff_t index)
 {
 	struct page *oldpage, *newpage;
+	struct folio *old, *new;
 	struct address_space *swap_mapping;
 	swp_entry_t entry;
 	pgoff_t swap_index;
@@ -1673,7 +1674,9 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
 	xa_lock_irq(&swap_mapping->i_pages);
 	error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
 	if (!error) {
-		mem_cgroup_migrate(oldpage, newpage);
+		old = page_folio(oldpage);
+		new = page_folio(newpage);
+		mem_cgroup_migrate(old, new);
 		__inc_lruvec_page_state(newpage, NR_FILE_PAGES);
 		__dec_lruvec_page_state(oldpage, NR_FILE_PAGES);
 	}

mm/swap.c

@@ -80,10 +80,11 @@ static DEFINE_PER_CPU(struct lru_pvecs, lru_pvecs) = {
 static void __page_cache_release(struct page *page)
 {
 	if (PageLRU(page)) {
+		struct folio *folio = page_folio(page);
 		struct lruvec *lruvec;
 		unsigned long flags;
 
-		lruvec = lock_page_lruvec_irqsave(page, &flags);
+		lruvec = folio_lruvec_lock_irqsave(folio, &flags);
 		del_page_from_lru_list(page, lruvec);
 		__clear_page_lru_flags(page);
 		unlock_page_lruvec_irqrestore(lruvec, flags);
@@ -94,7 +95,7 @@ static void __page_cache_release(struct page *page)
 static void __put_single_page(struct page *page)
 {
 	__page_cache_release(page);
-	mem_cgroup_uncharge(page);
+	mem_cgroup_uncharge(page_folio(page));
 	free_unref_page(page, 0);
 }
 
@@ -188,12 +189,13 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
 
 	for (i = 0; i < pagevec_count(pvec); i++) {
 		struct page *page = pvec->pages[i];
+		struct folio *folio = page_folio(page);
 
 		/* block memcg migration during page moving between lru */
 		if (!TestClearPageLRU(page))
 			continue;
 
-		lruvec = relock_page_lruvec_irqsave(page, lruvec, &flags);
+		lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags);
 		(*move_fn)(page, lruvec);
 
 		SetPageLRU(page);
@@ -206,11 +208,13 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
 
 static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec)
 {
-	if (!PageUnevictable(page)) {
+	struct folio *folio = page_folio(page);
-		del_page_from_lru_list(page, lruvec);
+
-		ClearPageActive(page);
+	if (!folio_test_unevictable(folio)) {
-		add_page_to_lru_list_tail(page, lruvec);
+		lruvec_del_folio(lruvec, folio);
-		__count_vm_events(PGROTATED, thp_nr_pages(page));
+		folio_clear_active(folio);
+		lruvec_add_folio_tail(lruvec, folio);
+		__count_vm_events(PGROTATED, folio_nr_pages(folio));
 	}
 }
 
@@ -227,23 +231,23 @@ static bool pagevec_add_and_need_flush(struct pagevec *pvec, struct page *page)
 }
 
 /*
- * Writeback is about to end against a page which has been marked for immediate
+ * Writeback is about to end against a folio which has been marked for
- * reclaim.  If it still appears to be reclaimable, move it to the tail of the
+ * immediate reclaim.  If it still appears to be reclaimable, move it
- * inactive list.
+ * to the tail of the inactive list.
  *
- * rotate_reclaimable_page() must disable IRQs, to prevent nasty races.
+ * folio_rotate_reclaimable() must disable IRQs, to prevent nasty races.
  */
-void rotate_reclaimable_page(struct page *page)
+void folio_rotate_reclaimable(struct folio *folio)
 {
-	if (!PageLocked(page) && !PageDirty(page) &&
+	if (!folio_test_locked(folio) && !folio_test_dirty(folio) &&
-	    !PageUnevictable(page) && PageLRU(page)) {
+	    !folio_test_unevictable(folio) && folio_test_lru(folio)) {
 		struct pagevec *pvec;
 		unsigned long flags;
 
-		get_page(page);
+		folio_get(folio);
 		local_lock_irqsave(&lru_rotate.lock, flags);
 		pvec = this_cpu_ptr(&lru_rotate.pvec);
-		if (pagevec_add_and_need_flush(pvec, page))
+		if (pagevec_add_and_need_flush(pvec, &folio->page))
 			pagevec_lru_move_fn(pvec, pagevec_move_tail_fn);
 		local_unlock_irqrestore(&lru_rotate.lock, flags);
 	}
@@ -289,21 +293,21 @@ void lru_note_cost(struct lruvec *lruvec, bool file, unsigned int nr_pages)
 	} while ((lruvec = parent_lruvec(lruvec)));
 }
 
-void lru_note_cost_page(struct page *page)
+void lru_note_cost_folio(struct folio *folio)
 {
-	lru_note_cost(mem_cgroup_page_lruvec(page),
+	lru_note_cost(folio_lruvec(folio), folio_is_file_lru(folio),
-		      page_is_file_lru(page), thp_nr_pages(page));
+			folio_nr_pages(folio));
 }
 
-static void __activate_page(struct page *page, struct lruvec *lruvec)
+static void __folio_activate(struct folio *folio, struct lruvec *lruvec)
 {
-	if (!PageActive(page) && !PageUnevictable(page)) {
+	if (!folio_test_active(folio) && !folio_test_unevictable(folio)) {
-		int nr_pages = thp_nr_pages(page);
+		long nr_pages = folio_nr_pages(folio);
 
-		del_page_from_lru_list(page, lruvec);
+		lruvec_del_folio(lruvec, folio);
-		SetPageActive(page);
+		folio_set_active(folio);
-		add_page_to_lru_list(page, lruvec);
+		lruvec_add_folio(lruvec, folio);
-		trace_mm_lru_activate(page);
+		trace_mm_lru_activate(folio);
 
 		__count_vm_events(PGACTIVATE, nr_pages);
 		__count_memcg_events(lruvec_memcg(lruvec), PGACTIVATE,
@@ -312,6 +316,11 @@ static void __activate_page(struct page *page, struct lruvec *lruvec)
 }
 
 #ifdef CONFIG_SMP
+static void __activate_page(struct page *page, struct lruvec *lruvec)
+{
+	return __folio_activate(page_folio(page), lruvec);
+}
+
 static void activate_page_drain(int cpu)
 {
 	struct pagevec *pvec = &per_cpu(lru_pvecs.activate_page, cpu);
@@ -325,16 +334,16 @@ static bool need_activate_page_drain(int cpu)
 	return pagevec_count(&per_cpu(lru_pvecs.activate_page, cpu)) != 0;
 }
 
-static void activate_page(struct page *page)
+static void folio_activate(struct folio *folio)
 {
-	page = compound_head(page);
+	if (folio_test_lru(folio) && !folio_test_active(folio) &&
-	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+	    !folio_test_unevictable(folio)) {
 		struct pagevec *pvec;
 
+		folio_get(folio);
 		local_lock(&lru_pvecs.lock);
 		pvec = this_cpu_ptr(&lru_pvecs.activate_page);
-		get_page(page);
+		if (pagevec_add_and_need_flush(pvec, &folio->page))
-		if (pagevec_add_and_need_flush(pvec, page))
 			pagevec_lru_move_fn(pvec, __activate_page);
 		local_unlock(&lru_pvecs.lock);
 	}
@@ -345,21 +354,20 @@ static inline void activate_page_drain(int cpu)
 {
 }
 
-static void activate_page(struct page *page)
+static void folio_activate(struct folio *folio)
 {
 	struct lruvec *lruvec;
 
-	page = compound_head(page);
+	if (folio_test_clear_lru(folio)) {
-	if (TestClearPageLRU(page)) {
+		lruvec = folio_lruvec_lock_irq(folio);
-		lruvec = lock_page_lruvec_irq(page);
+		__folio_activate(folio, lruvec);
-		__activate_page(page, lruvec);
 		unlock_page_lruvec_irq(lruvec);
-		SetPageLRU(page);
+		folio_set_lru(folio);
 	}
 }
 #endif
 
-static void __lru_cache_activate_page(struct page *page)
+static void __lru_cache_activate_folio(struct folio *folio)
 {
 	struct pagevec *pvec;
 	int i;
@@ -380,8 +388,8 @@ static void __lru_cache_activate_page(struct page *page)
 	for (i = pagevec_count(pvec) - 1; i >= 0; i--) {
 		struct page *pagevec_page = pvec->pages[i];
 
-		if (pagevec_page == page) {
+		if (pagevec_page == &folio->page) {
-			SetPageActive(page);
+			folio_set_active(folio);
 			break;
 		}
 	}
@@ -399,61 +407,59 @@ static void __lru_cache_activate_page(struct page *page)
  * When a newly allocated page is not yet visible, so safe for non-atomic ops,
  * __SetPageReferenced(page) may be substituted for mark_page_accessed(page).
  */
-void mark_page_accessed(struct page *page)
+void folio_mark_accessed(struct folio *folio)
 {
-	page = compound_head(page);
+	if (!folio_test_referenced(folio)) {
-
+		folio_set_referenced(folio);
-	if (!PageReferenced(page)) {
+	} else if (folio_test_unevictable(folio)) {
-		SetPageReferenced(page);
-	} else if (PageUnevictable(page)) {
 		/*
 		 * Unevictable pages are on the "LRU_UNEVICTABLE" list. But,
 		 * this list is never rotated or maintained, so marking an
 		 * evictable page accessed has no effect.
 		 */
-	} else if (!PageActive(page)) {
+	} else if (!folio_test_active(folio)) {
 		/*
 		 * If the page is on the LRU, queue it for activation via
 		 * lru_pvecs.activate_page. Otherwise, assume the page is on a
 		 * pagevec, mark it active and it'll be moved to the active
 		 * LRU on the next drain.
 		 */
-		if (PageLRU(page))
+		if (folio_test_lru(folio))
-			activate_page(page);
+			folio_activate(folio);
 		else
-			__lru_cache_activate_page(page);
+			__lru_cache_activate_folio(folio);
-		ClearPageReferenced(page);
+		folio_clear_referenced(folio);
-		workingset_activation(page);
+		workingset_activation(folio);
 	}
-	if (page_is_idle(page))
+	if (folio_test_idle(folio))
-		clear_page_idle(page);
+		folio_clear_idle(folio);
 }
-EXPORT_SYMBOL(mark_page_accessed);
+EXPORT_SYMBOL(folio_mark_accessed);
 
 /**
- * lru_cache_add - add a page to a page list
+ * folio_add_lru - Add a folio to an LRU list.
- * @page: the page to be added to the LRU.
+ * @folio: The folio to be added to the LRU.
  *
- * Queue the page for addition to the LRU via pagevec. The decision on whether
+ * Queue the folio for addition to the LRU. The decision on whether
  * to add the page to the [in]active [file|anon] list is deferred until the
- * pagevec is drained. This gives a chance for the caller of lru_cache_add()
+ * pagevec is drained. This gives a chance for the caller of folio_add_lru()
- * have the page added to the active list using mark_page_accessed().
+ * have the folio added to the active list using folio_mark_accessed().
  */
-void lru_cache_add(struct page *page)
+void folio_add_lru(struct folio *folio)
 {
 	struct pagevec *pvec;
 
-	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
+	VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
-	VM_BUG_ON_PAGE(PageLRU(page), page);
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
 
-	get_page(page);
+	folio_get(folio);
 	local_lock(&lru_pvecs.lock);
 	pvec = this_cpu_ptr(&lru_pvecs.lru_add);
-	if (pagevec_add_and_need_flush(pvec, page))
+	if (pagevec_add_and_need_flush(pvec, &folio->page))
 		__pagevec_lru_add(pvec);
 	local_unlock(&lru_pvecs.lock);
 }
-EXPORT_SYMBOL(lru_cache_add);
+EXPORT_SYMBOL(folio_add_lru);
 
 /**
  * lru_cache_add_inactive_or_unevictable
@@ -888,11 +894,12 @@ void release_pages(struct page **pages, int nr)
 	int i;
 	LIST_HEAD(pages_to_free);
 	struct lruvec *lruvec = NULL;
-	unsigned long flags;
+	unsigned long flags = 0;
 	unsigned int lock_batch;
 
 	for (i = 0; i < nr; i++) {
 		struct page *page = pages[i];
+		struct folio *folio = page_folio(page);
 
 		/*
 		 * Make sure the IRQ-safe lock-holding time does not get
@@ -904,7 +911,7 @@ void release_pages(struct page **pages, int nr)
 			lruvec = NULL;
 		}
 
-		page = compound_head(page);
+		page = &folio->page;
 		if (is_huge_zero_page(page))
 			continue;
 
@@ -943,7 +950,7 @@ void release_pages(struct page **pages, int nr)
 		if (PageLRU(page)) {
 			struct lruvec *prev_lruvec = lruvec;
 
-			lruvec = relock_page_lruvec_irqsave(page, lruvec,
+			lruvec = folio_lruvec_relock_irqsave(folio, lruvec,
 									&flags);
 			if (prev_lruvec != lruvec)
 				lock_batch = 0;
@@ -985,17 +992,18 @@ void __pagevec_release(struct pagevec *pvec)
 }
 EXPORT_SYMBOL(__pagevec_release);
 
-static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec)
+static void __pagevec_lru_add_fn(struct folio *folio, struct lruvec *lruvec)
 {
-	int was_unevictable = TestClearPageUnevictable(page);
+	int was_unevictable = folio_test_clear_unevictable(folio);
-	int nr_pages = thp_nr_pages(page);
+	long nr_pages = folio_nr_pages(folio);
 
-	VM_BUG_ON_PAGE(PageLRU(page), page);
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
 
 	/*
-	 * Page becomes evictable in two ways:
+	 * A folio becomes evictable in two ways:
 	 * 1) Within LRU lock [munlock_vma_page() and __munlock_pagevec()].
-	 * 2) Before acquiring LRU lock to put the page to correct LRU and then
+	 * 2) Before acquiring LRU lock to put the folio on the correct LRU
+	 *    and then
 	 *   a) do PageLRU check with lock [check_move_unevictable_pages]
 	 *   b) do PageLRU check before lock [clear_page_mlock]
 	 *
@@ -1004,35 +1012,36 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec)
 	 *
 	 * #0: __pagevec_lru_add_fn		#1: clear_page_mlock
 	 *
-	 * SetPageLRU()				TestClearPageMlocked()
+	 * folio_set_lru()			folio_test_clear_mlocked()
 	 * smp_mb() // explicit ordering	// above provides strict
 	 *					// ordering
-	 * PageMlocked()			PageLRU()
+	 * folio_test_mlocked()			folio_test_lru()
 	 *
 	 *
-	 * if '#1' does not observe setting of PG_lru by '#0' and fails
+	 * if '#1' does not observe setting of PG_lru by '#0' and
-	 * isolation, the explicit barrier will make sure that page_evictable
+	 * fails isolation, the explicit barrier will make sure that
-	 * check will put the page in correct LRU. Without smp_mb(), SetPageLRU
+	 * folio_evictable check will put the folio on the correct
-	 * can be reordered after PageMlocked check and can make '#1' to fail
+	 * LRU. Without smp_mb(), folio_set_lru() can be reordered
-	 * the isolation of the page whose Mlocked bit is cleared (#0 is also
+	 * after folio_test_mlocked() check and can make '#1' fail the
-	 * looking at the same page) and the evictable page will be stranded
+	 * isolation of the folio whose mlocked bit is cleared (#0 is
-	 * in an unevictable LRU.
+	 * also looking at the same folio) and the evictable folio will
+	 * be stranded on an unevictable LRU.
 	 */
-	SetPageLRU(page);
+	folio_set_lru(folio);
 	smp_mb__after_atomic();
 
-	if (page_evictable(page)) {
+	if (folio_evictable(folio)) {
 		if (was_unevictable)
 			__count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
 	} else {
-		ClearPageActive(page);
+		folio_clear_active(folio);
-		SetPageUnevictable(page);
+		folio_set_unevictable(folio);
 		if (!was_unevictable)
 			__count_vm_events(UNEVICTABLE_PGCULLED, nr_pages);
 	}
 
-	add_page_to_lru_list(page, lruvec);
+	lruvec_add_folio(lruvec, folio);
-	trace_mm_lru_insertion(page);
+	trace_mm_lru_insertion(folio);
 }
 
 /*
@@ -1046,10 +1055,10 @@ void __pagevec_lru_add(struct pagevec *pvec)
 	unsigned long flags = 0;
 
 	for (i = 0; i < pagevec_count(pvec); i++) {
-		struct page *page = pvec->pages[i];
+		struct folio *folio = page_folio(pvec->pages[i]);
 
-		lruvec = relock_page_lruvec_irqsave(page, lruvec, &flags);
+		lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags);
-		__pagevec_lru_add_fn(page, lruvec);
+		__pagevec_lru_add_fn(folio, lruvec);
 	}
 	if (lruvec)
 		unlock_page_lruvec_irqrestore(lruvec, flags);

mm/swap_state.c

@@ -498,7 +498,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 	mem_cgroup_swapin_uncharge_swap(entry);
 
 	if (shadow)
-		workingset_refault(page, shadow);
+		workingset_refault(page_folio(page), shadow);
 
 	/* Caller will initiate read into locked page */
 	lru_cache_add(page);

mm/swapfile.c

@@ -3534,13 +3534,13 @@ struct swap_info_struct *page_swap_info(struct page *page)
 }
 
 /*
- * out-of-line __page_file_ methods to avoid include hell.
+ * out-of-line methods to avoid include hell.
  */
-struct address_space *__page_file_mapping(struct page *page)
+struct address_space *swapcache_mapping(struct folio *folio)
 {
-	return page_swap_info(page)->swap_file->f_mapping;
+	return page_swap_info(&folio->page)->swap_file->f_mapping;
 }
-EXPORT_SYMBOL_GPL(__page_file_mapping);
+EXPORT_SYMBOL_GPL(swapcache_mapping);
 
 pgoff_t __page_file_index(struct page *page)
 {

mm/userfaultfd.c

@@ -164,7 +164,7 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 	__SetPageUptodate(page);
 
 	ret = -ENOMEM;
-	if (mem_cgroup_charge(page, dst_mm, GFP_KERNEL))
+	if (mem_cgroup_charge(page_folio(page), dst_mm, GFP_KERNEL))
 		goto out_release;
 
 	ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr,

mm/util.c

@@ -654,81 +654,78 @@ void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
 }
 EXPORT_SYMBOL(kvrealloc);
 
-static inline void *__page_rmapping(struct page *page)
-{
-	unsigned long mapping;
-
-	mapping = (unsigned long)page->mapping;
-	mapping &= ~PAGE_MAPPING_FLAGS;
-
-	return (void *)mapping;
-}
-
 /* Neutral page->mapping pointer to address_space or anon_vma or other */
 void *page_rmapping(struct page *page)
 {
-	page = compound_head(page);
+	return folio_raw_mapping(page_folio(page));
-	return __page_rmapping(page);
 }
 
-/*
+/**
- * Return true if this page is mapped into pagetables.
+ * folio_mapped - Is this folio mapped into userspace?
- * For compound page it returns true if any subpage of compound page is mapped.
+ * @folio: The folio.
+ *
+ * Return: True if any page in this folio is referenced by user page tables.
  */
-bool page_mapped(struct page *page)
+bool folio_mapped(struct folio *folio)
 {
-	int i;
+	long i, nr;
 
-	if (likely(!PageCompound(page)))
+	if (folio_test_single(folio))
-		return atomic_read(&page->_mapcount) >= 0;
+		return atomic_read(&folio->_mapcount) >= 0;
-	page = compound_head(page);
+	if (atomic_read(folio_mapcount_ptr(folio)) >= 0)
-	if (atomic_read(compound_mapcount_ptr(page)) >= 0)
 		return true;
-	if (PageHuge(page))
+	if (folio_test_hugetlb(folio))
 		return false;
-	for (i = 0; i < compound_nr(page); i++) {
+
-		if (atomic_read(&page[i]._mapcount) >= 0)
+	nr = folio_nr_pages(folio);
+	for (i = 0; i < nr; i++) {
+		if (atomic_read(&folio_page(folio, i)->_mapcount) >= 0)
 			return true;
 	}
 	return false;
 }
-EXPORT_SYMBOL(page_mapped);
+EXPORT_SYMBOL(folio_mapped);
 
 struct anon_vma *page_anon_vma(struct page *page)
 {
-	unsigned long mapping;
+	struct folio *folio = page_folio(page);
+	unsigned long mapping = (unsigned long)folio->mapping;
 
-	page = compound_head(page);
-	mapping = (unsigned long)page->mapping;
 	if ((mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON)
 		return NULL;
-	return __page_rmapping(page);
+	return (void *)(mapping - PAGE_MAPPING_ANON);
 }
 
-struct address_space *page_mapping(struct page *page)
+/**
+ * folio_mapping - Find the mapping where this folio is stored.
+ * @folio: The folio.
+ *
+ * For folios which are in the page cache, return the mapping that this
+ * page belongs to.  Folios in the swap cache return the swap mapping
+ * this page is stored in (which is different from the mapping for the
+ * swap file or swap device where the data is stored).
+ *
+ * You can call this for folios which aren't in the swap cache or page
+ * cache and it will return NULL.
+ */
+struct address_space *folio_mapping(struct folio *folio)
 {
 	struct address_space *mapping;
 
-	page = compound_head(page);
-
 	/* This happens if someone calls flush_dcache_page on slab page */
-	if (unlikely(PageSlab(page)))
+	if (unlikely(folio_test_slab(folio)))
 		return NULL;
 
-	if (unlikely(PageSwapCache(page))) {
+	if (unlikely(folio_test_swapcache(folio)))
-		swp_entry_t entry;
+		return swap_address_space(folio_swap_entry(folio));
 
-		entry.val = page_private(page);
+	mapping = folio->mapping;
-		return swap_address_space(entry);
-	}
-
-	mapping = page->mapping;
 	if ((unsigned long)mapping & PAGE_MAPPING_ANON)
 		return NULL;
 
 	return (void *)((unsigned long)mapping & ~PAGE_MAPPING_FLAGS);
 }
-EXPORT_SYMBOL(page_mapping);
+EXPORT_SYMBOL(folio_mapping);
 
 /* Slow path of page_mapcount() for compound pages */
 int __page_mapcount(struct page *page)
@@ -750,13 +747,26 @@ int __page_mapcount(struct page *page)
 }
 EXPORT_SYMBOL_GPL(__page_mapcount);
 
-void copy_huge_page(struct page *dst, struct page *src)
+/**
+ * folio_copy - Copy the contents of one folio to another.
+ * @dst: Folio to copy to.
+ * @src: Folio to copy from.
+ *
+ * The bytes in the folio represented by @src are copied to @dst.
+ * Assumes the caller has validated that @dst is at least as large as @src.
+ * Can be called in atomic context for order-0 folios, but if the folio is
+ * larger, it may sleep.
+ */
+void folio_copy(struct folio *dst, struct folio *src)
 {
-	unsigned i, nr = compound_nr(src);
+	long i = 0;
+	long nr = folio_nr_pages(src);
 
-	for (i = 0; i < nr; i++) {
+	for (;;) {
+		copy_highpage(folio_page(dst, i), folio_page(src, i));
+		if (++i == nr)
+			break;
 		cond_resched();
-		copy_highpage(nth_page(dst, i), nth_page(src, i));
 	}
 }
 
@@ -1079,3 +1089,14 @@ void page_offline_end(void)
 	up_write(&page_offline_rwsem);
 }
 EXPORT_SYMBOL(page_offline_end);
+
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
+void flush_dcache_folio(struct folio *folio)
+{
+	long i, nr = folio_nr_pages(folio);
+
+	for (i = 0; i < nr; i++)
+		flush_dcache_page(folio_page(folio, i));
+}
+EXPORT_SYMBOL(flush_dcache_folio);
+#endif

mm/vmscan.c

@@ -2090,6 +2090,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
  */
 int isolate_lru_page(struct page *page)
 {
+	struct folio *folio = page_folio(page);
 	int ret = -EBUSY;
 
 	VM_BUG_ON_PAGE(!page_count(page), page);
@@ -2099,7 +2100,7 @@ int isolate_lru_page(struct page *page)
 		struct lruvec *lruvec;
 
 		get_page(page);
-		lruvec = lock_page_lruvec_irq(page);
+		lruvec = folio_lruvec_lock_irq(folio);
 		del_page_from_lru_list(page, lruvec);
 		unlock_page_lruvec_irq(lruvec);
 		ret = 0;
@@ -2199,7 +2200,7 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec,
 		 * All pages were isolated from the same lruvec (and isolation
 		 * inhibits memcg migration).
 		 */
-		VM_BUG_ON_PAGE(!page_matches_lruvec(page, lruvec), page);
+		VM_BUG_ON_PAGE(!folio_matches_lruvec(page_folio(page), lruvec), page);
 		add_page_to_lru_list(page, lruvec);
 		nr_pages = thp_nr_pages(page);
 		nr_moved += nr_pages;
@@ -4665,6 +4666,7 @@ void check_move_unevictable_pages(struct pagevec *pvec)
 
 	for (i = 0; i < pvec->nr; i++) {
 		struct page *page = pvec->pages[i];
+		struct folio *folio = page_folio(page);
 		int nr_pages;
 
 		if (PageTransTail(page))
@@ -4677,7 +4679,7 @@ void check_move_unevictable_pages(struct pagevec *pvec)
 		if (!TestClearPageLRU(page))
 			continue;
 
-		lruvec = relock_page_lruvec_irq(page, lruvec);
+		lruvec = folio_lruvec_relock_irq(folio, lruvec);
 		if (page_evictable(page) && PageUnevictable(page)) {
 			del_page_from_lru_list(page, lruvec);
 			ClearPageUnevictable(page);

mm/workingset.c

@@ -273,17 +273,17 @@ void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg)
 }
 
 /**
- * workingset_refault - evaluate the refault of a previously evicted page
+ * workingset_refault - Evaluate the refault of a previously evicted folio.
- * @page: the freshly allocated replacement page
+ * @folio: The freshly allocated replacement folio.
- * @shadow: shadow entry of the evicted page
+ * @shadow: Shadow entry of the evicted folio.
  *
  * Calculates and evaluates the refault distance of the previously
- * evicted page in the context of the node and the memcg whose memory
+ * evicted folio in the context of the node and the memcg whose memory
  * pressure caused the eviction.
  */
-void workingset_refault(struct page *page, void *shadow)
+void workingset_refault(struct folio *folio, void *shadow)
 {
-	bool file = page_is_file_lru(page);
+	bool file = folio_is_file_lru(folio);
 	struct mem_cgroup *eviction_memcg;
 	struct lruvec *eviction_lruvec;
 	unsigned long refault_distance;
@@ -295,16 +295,17 @@ void workingset_refault(struct page *page, void *shadow)
 	unsigned long refault;
 	bool workingset;
 	int memcgid;
+	long nr;
 
 	unpack_shadow(shadow, &memcgid, &pgdat, &eviction, &workingset);
 
 	rcu_read_lock();
 	/*
 	 * Look up the memcg associated with the stored ID. It might
-	 * have been deleted since the page's eviction.
+	 * have been deleted since the folio's eviction.
 	 *
 	 * Note that in rare events the ID could have been recycled
-	 * for a new cgroup that refaults a shared page. This is
+	 * for a new cgroup that refaults a shared folio. This is
 	 * impossible to tell from the available data. However, this
 	 * should be a rare and limited disturbance, and activations
 	 * are always speculative anyway. Ultimately, it's the aging
@@ -340,17 +341,18 @@ void workingset_refault(struct page *page, void *shadow)
 	refault_distance = (refault - eviction) & EVICTION_MASK;
 
 	/*
-	 * The activation decision for this page is made at the level
+	 * The activation decision for this folio is made at the level
 	 * where the eviction occurred, as that is where the LRU order
-	 * during page reclaim is being determined.
+	 * during folio reclaim is being determined.
 	 *
-	 * However, the cgroup that will own the page is the one that
+	 * However, the cgroup that will own the folio is the one that
 	 * is actually experiencing the refault event.
 	 */
-	memcg = page_memcg(page);
+	nr = folio_nr_pages(folio);
+	memcg = folio_memcg(folio);
 	lruvec = mem_cgroup_lruvec(memcg, pgdat);
 
-	inc_lruvec_state(lruvec, WORKINGSET_REFAULT_BASE + file);
+	mod_lruvec_state(lruvec, WORKINGSET_REFAULT_BASE + file, nr);
 
 	mem_cgroup_flush_stats();
 	/*
@@ -376,16 +378,16 @@ void workingset_refault(struct page *page, void *shadow)
 	if (refault_distance > workingset_size)
 		goto out;
 
-	SetPageActive(page);
+	folio_set_active(folio);
-	workingset_age_nonresident(lruvec, thp_nr_pages(page));
+	workingset_age_nonresident(lruvec, nr);
-	inc_lruvec_state(lruvec, WORKINGSET_ACTIVATE_BASE + file);
+	mod_lruvec_state(lruvec, WORKINGSET_ACTIVATE_BASE + file, nr);
 
-	/* Page was active prior to eviction */
+	/* Folio was active prior to eviction */
 	if (workingset) {
-		SetPageWorkingset(page);
+		folio_set_workingset(folio);
 		/* XXX: Move to lru_cache_add() when it supports new vs putback */
-		lru_note_cost_page(page);
+		lru_note_cost_folio(folio);
-		inc_lruvec_state(lruvec, WORKINGSET_RESTORE_BASE + file);
+		mod_lruvec_state(lruvec, WORKINGSET_RESTORE_BASE + file, nr);
 	}
 out:
 	rcu_read_unlock();
@@ -393,12 +395,11 @@ out:
 
 /**
  * workingset_activation - note a page activation
- * @page: page that is being activated
+ * @folio: Folio that is being activated.
  */
-void workingset_activation(struct page *page)
+void workingset_activation(struct folio *folio)
 {
 	struct mem_cgroup *memcg;
-	struct lruvec *lruvec;
 
 	rcu_read_lock();
 	/*
@@ -408,11 +409,10 @@ void workingset_activation(struct page *page)
 	 * XXX: See workingset_refault() - this should return
 	 * root_mem_cgroup even for !CONFIG_MEMCG.
 	 */
-	memcg = page_memcg_rcu(page);
+	memcg = folio_memcg_rcu(folio);
 	if (!mem_cgroup_disabled() && !memcg)
 		goto out;
-	lruvec = mem_cgroup_page_lruvec(page);
+	workingset_age_nonresident(folio_lruvec(folio), folio_nr_pages(folio));
-	workingset_age_nonresident(lruvec, thp_nr_pages(page));
 out:
 	rcu_read_unlock();
 }