1 files changed, 261 insertions, 197 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index 7b4ea4c4a46b..12467c1bd711 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -19,36 +19,34 @@
 #include <linux/highmem.h>
 #include <linux/pagevec.h>
 #include <linux/task_io_accounting_ops.h>
-#include <linux/buffer_head.h>	/* grr. try_to_release_page */
 #include <linux/shmem_fs.h>
 #include <linux/rmap.h>
 #include "internal.h"
 
-/*
- * Regular page slots are stabilized by the page lock even without the tree
- * itself locked.  These unlocked entries need verification under the tree
- * lock.
- */
-static inline void __clear_shadow_entry(struct address_space *mapping,
-				pgoff_t index, void *entry)
+static void clear_shadow_entries(struct address_space *mapping,
+				 unsigned long start, unsigned long max)
 {
-	XA_STATE(xas, &mapping->i_pages, index);
+	XA_STATE(xas, &mapping->i_pages, start);
+	struct folio *folio;
 
-	xas_set_update(&xas, workingset_update_node);
-	if (xas_load(&xas) != entry)
+	/* Handled by shmem itself, or for DAX we do nothing. */
+	if (shmem_mapping(mapping) || dax_mapping(mapping))
 		return;
-	xas_store(&xas, NULL);
-}
 
-static void clear_shadow_entry(struct address_space *mapping, pgoff_t index,
-			       void *entry)
-{
+	xas_set_update(&xas, workingset_update_node);
+
 	spin_lock(&mapping->host->i_lock);
-	xa_lock_irq(&mapping->i_pages);
-	__clear_shadow_entry(mapping, index, entry);
-	xa_unlock_irq(&mapping->i_pages);
+	xas_lock_irq(&xas);
+
+	/* Clear all shadow entries from start to max */
+	xas_for_each(&xas, folio, max) {
+		if (xa_is_value(folio))
+			xas_store(&xas, NULL);
+	}
+
+	xas_unlock_irq(&xas);
 	if (mapping_shrinkable(mapping))
-		inode_add_lru(mapping->host);
+		inode_lru_list_add(mapping->host);
 	spin_unlock(&mapping->host->i_lock);
 }
 
@@ -56,84 +54,67 @@ static void clear_shadow_entry(struct address_space *mapping, pgoff_t index,
  * Unconditionally remove exceptional entries. Usually called from truncate
  * path. Note that the folio_batch may be altered by this function by removing
  * exceptional entries similar to what folio_batch_remove_exceptionals() does.
+ * Please note that indices[] has entries in ascending order as guaranteed by
+ * either find_get_entries() or find_lock_entries().
  */
 static void truncate_folio_batch_exceptionals(struct address_space *mapping,
 				struct folio_batch *fbatch, pgoff_t *indices)
 {
+	XA_STATE(xas, &mapping->i_pages, indices[0]);
+	int nr = folio_batch_count(fbatch);
+	struct folio *folio;
 	int i, j;
-	bool dax;
 
 	/* Handled by shmem itself */
 	if (shmem_mapping(mapping))
 		return;
 
-	for (j = 0; j < folio_batch_count(fbatch); j++)
+	for (j = 0; j < nr; j++)
 		if (xa_is_value(fbatch->folios[j]))
 			break;
 
-	if (j == folio_batch_count(fbatch))
+	if (j == nr)
 		return;
 
-	dax = dax_mapping(mapping);
-	if (!dax) {
-		spin_lock(&mapping->host->i_lock);
-		xa_lock_irq(&mapping->i_pages);
-	}
-
-	for (i = j; i < folio_batch_count(fbatch); i++) {
-		struct folio *folio = fbatch->folios[i];
-		pgoff_t index = indices[i];
+	if (dax_mapping(mapping)) {
+		for (i = j; i < nr; i++) {
+			if (xa_is_value(fbatch->folios[i])) {
+				/*
+				 * File systems should already have called
+				 * dax_break_layout_entry() to remove all DAX
+				 * entries while holding a lock to prevent
+				 * establishing new entries. Therefore we
+				 * shouldn't find any here.
+				 */
+				WARN_ON_ONCE(1);
 
-		if (!xa_is_value(folio)) {
-			fbatch->folios[j++] = folio;
-			continue;
+				/*
+				 * Delete the mapping so truncate_pagecache()
+				 * doesn't loop forever.
+				 */
+				dax_delete_mapping_entry(mapping, indices[i]);
+			}
 		}
+		goto out;
+	}
 
-		if (unlikely(dax)) {
-			dax_delete_mapping_entry(mapping, index);
-			continue;
-		}
+	xas_set(&xas, indices[j]);
+	xas_set_update(&xas, workingset_update_node);
 
-		__clear_shadow_entry(mapping, index, folio);
-	}
+	spin_lock(&mapping->host->i_lock);
+	xas_lock_irq(&xas);
 
-	if (!dax) {
-		xa_unlock_irq(&mapping->i_pages);
-		if (mapping_shrinkable(mapping))
-			inode_add_lru(mapping->host);
-		spin_unlock(&mapping->host->i_lock);
+	xas_for_each(&xas, folio, indices[nr-1]) {
+		if (xa_is_value(folio))
+			xas_store(&xas, NULL);
 	}
-	fbatch->nr = j;
-}
 
-/*
- * Invalidate exceptional entry if easily possible. This handles exceptional
- * entries for invalidate_inode_pages().
- */
-static int invalidate_exceptional_entry(struct address_space *mapping,
-					pgoff_t index, void *entry)
-{
-	/* Handled by shmem itself, or for DAX we do nothing. */
-	if (shmem_mapping(mapping) || dax_mapping(mapping))
-		return 1;
-	clear_shadow_entry(mapping, index, entry);
-	return 1;
-}
-
-/*
- * Invalidate exceptional entry if clean. This handles exceptional entries for
- * invalidate_inode_pages2() so for DAX it evicts only clean entries.
- */
-static int invalidate_exceptional_entry2(struct address_space *mapping,
-					 pgoff_t index, void *entry)
-{
-	/* Handled by shmem itself */
-	if (shmem_mapping(mapping))
-		return 1;
-	if (dax_mapping(mapping))
-		return dax_invalidate_mapping_entry_sync(mapping, index);
-	clear_shadow_entry(mapping, index, entry);
-	return 1;
+	xas_unlock_irq(&xas);
+	if (mapping_shrinkable(mapping))
+		inode_lru_list_add(mapping->host);
+	spin_unlock(&mapping->host->i_lock);
+out:
+	folio_batch_remove_exceptionals(fbatch);
 }
 
 /**
@@ -175,7 +156,7 @@ static void truncate_cleanup_folio(struct folio *folio)
 	if (folio_mapped(folio))
 		unmap_mapping_folio(folio);
 
-	if (folio_has_private(folio))
+	if (folio_needs_release(folio))
 		folio_invalidate(folio, 0, folio_size(folio));
 
 	/*
@@ -184,7 +165,6 @@ static void truncate_cleanup_folio(struct folio *folio)
 	 * Hence dirty accounting check is placed after invalidation.
 	 */
 	folio_cancel_dirty(folio);
-	folio_clear_mappedtodisk(folio);
 }
 
 int truncate_inode_folio(struct address_space *mapping, struct folio *folio)
@@ -197,6 +177,32 @@ int truncate_inode_folio(struct address_space *mapping, struct folio *folio)
 	return 0;
 }
 
+static int try_folio_split_or_unmap(struct folio *folio, struct page *split_at,
+				    unsigned long min_order)
+{
+	enum ttu_flags ttu_flags =
+		TTU_SYNC |
+		TTU_SPLIT_HUGE_PMD |
+		TTU_IGNORE_MLOCK;
+	int ret;
+
+	ret = try_folio_split_to_order(folio, split_at, min_order);
+
+	/*
+	 * If the split fails, unmap the folio, so it will be refaulted
+	 * with PTEs to respect SIGBUS semantics.
+	 *
+	 * Make an exception for shmem/tmpfs that for long time
+	 * intentionally mapped with PMDs across i_size.
+	 */
+	if (ret && !shmem_mapping(folio->mapping)) {
+		try_to_unmap(folio, ttu_flags);
+		WARN_ON(folio_mapped(folio));
+	}
+
+	return ret;
+}
+
 /*
  * Handle partial folios.  The folio may be entirely within the
  * range if a split has raced with us.  If not, we zero the part of the
@@ -211,20 +217,22 @@ int truncate_inode_folio(struct address_space *mapping, struct folio *folio)
 bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end)
 {
 	loff_t pos = folio_pos(folio);
+	size_t size = folio_size(folio);
 	unsigned int offset, length;
+	struct page *split_at, *split_at2;
+	unsigned int min_order;
 
 	if (pos < start)
 		offset = start - pos;
 	else
 		offset = 0;
-	length = folio_size(folio);
-	if (pos + length <= (u64)end)
-		length = length - offset;
+	if (pos + size <= (u64)end)
+		length = size - offset;
 	else
 		length = end + 1 - pos - offset;
 
 	folio_wait_writeback(folio);
-	if (length == folio_size(folio)) {
+	if (length == size) {
 		truncate_inode_folio(folio->mapping, folio);
 		return true;
 	}
@@ -234,14 +242,51 @@ bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end)
 	 * doing a complex calculation here, and then doing the zeroing
 	 * anyway if the page split fails.
 	 */
-	folio_zero_range(folio, offset, length);
+	if (!mapping_inaccessible(folio->mapping))
+		folio_zero_range(folio, offset, length);
 
-	if (folio_has_private(folio))
+	if (folio_needs_release(folio))
 		folio_invalidate(folio, offset, length);
 	if (!folio_test_large(folio))
 		return true;
-	if (split_folio(folio) == 0)
+
+	min_order = mapping_min_folio_order(folio->mapping);
+	split_at = folio_page(folio, PAGE_ALIGN_DOWN(offset) / PAGE_SIZE);
+	if (!try_folio_split_or_unmap(folio, split_at, min_order)) {
+		/*
+		 * try to split at offset + length to make sure folios within
+		 * the range can be dropped, especially to avoid memory waste
+		 * for shmem truncate
+		 */
+		struct folio *folio2;
+
+		if (offset + length == size)
+			goto no_split;
+
+		split_at2 = folio_page(folio,
+				PAGE_ALIGN_DOWN(offset + length) / PAGE_SIZE);
+		folio2 = page_folio(split_at2);
+
+		if (!folio_try_get(folio2))
+			goto no_split;
+
+		if (!folio_test_large(folio2))
+			goto out;
+
+		if (!folio_trylock(folio2))
+			goto out;
+
+		/* make sure folio2 is large and does not change its mapping */
+		if (folio_test_large(folio2) &&
+		    folio2->mapping == folio->mapping)
+			try_folio_split_or_unmap(folio2, split_at2, min_order);
+
+		folio_unlock(folio2);
+out:
+		folio_put(folio2);
+no_split:
 		return true;
+	}
 	if (folio_test_dirty(folio))
 		return false;
 	truncate_inode_folio(folio->mapping, folio);
@@ -251,10 +296,9 @@ bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end)
 /*
  * Used to get rid of pages on hardware memory corruption.
  */
-int generic_error_remove_page(struct address_space *mapping, struct page *page)
+int generic_error_remove_folio(struct address_space *mapping,
+		struct folio *folio)
 {
-	VM_BUG_ON_PAGE(PageTail(page), page);
-
 	if (!mapping)
 		return -EINVAL;
 	/*
@@ -263,47 +307,39 @@ int generic_error_remove_page(struct address_space *mapping, struct page *page)
 	 */
 	if (!S_ISREG(mapping->host->i_mode))
 		return -EIO;
-	return truncate_inode_folio(mapping, page_folio(page));
+	return truncate_inode_folio(mapping, folio);
 }
-EXPORT_SYMBOL(generic_error_remove_page);
+EXPORT_SYMBOL(generic_error_remove_folio);
 
-static long mapping_evict_folio(struct address_space *mapping,
-		struct folio *folio)
+/**
+ * mapping_evict_folio() - Remove an unused folio from the page-cache.
+ * @mapping: The mapping this folio belongs to.
+ * @folio: The folio to remove.
+ *
+ * Safely remove one folio from the page cache.
+ * It only drops clean, unused folios.
+ *
+ * Context: Folio must be locked.
+ * Return: The number of pages successfully removed.
+ */
+long mapping_evict_folio(struct address_space *mapping, struct folio *folio)
 {
+	/* The page may have been truncated before it was locked */
+	if (!mapping)
+		return 0;
 	if (folio_test_dirty(folio) || folio_test_writeback(folio))
 		return 0;
 	/* The refcount will be elevated if any page in the folio is mapped */
 	if (folio_ref_count(folio) >
 			folio_nr_pages(folio) + folio_has_private(folio) + 1)
 		return 0;
-	if (folio_has_private(folio) && !filemap_release_folio(folio, 0))
+	if (!filemap_release_folio(folio, 0))
 		return 0;
 
 	return remove_mapping(mapping, folio);
 }
 
 /**
- * invalidate_inode_page() - Remove an unused page from the pagecache.
- * @page: The page to remove.
- *
- * Safely invalidate one page from its pagecache mapping.
- * It only drops clean, unused pages.
- *
- * Context: Page must be locked.
- * Return: The number of pages successfully removed.
- */
-long invalidate_inode_page(struct page *page)
-{
-	struct folio *folio = page_folio(page);
-	struct address_space *mapping = folio_mapping(folio);
-
-	/* The page may have been truncated before it was locked */
-	if (!mapping)
-		return 0;
-	return mapping_evict_folio(mapping, folio);
-}
-
-/**
  * truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets
  * @mapping: mapping to truncate
  * @lstart: offset from which to truncate
@@ -328,7 +364,7 @@ long invalidate_inode_page(struct page *page)
  * page aligned properly.
  */
 void truncate_inode_pages_range(struct address_space *mapping,
-				loff_t lstart, loff_t lend)
+				loff_t lstart, uoff_t lend)
 {
 	pgoff_t		start;		/* inclusive */
 	pgoff_t		end;		/* exclusive */
@@ -375,10 +411,10 @@ void truncate_inode_pages_range(struct address_space *mapping,
 
 	same_folio = (lstart >> PAGE_SHIFT) == (lend >> PAGE_SHIFT);
 	folio = __filemap_get_folio(mapping, lstart >> PAGE_SHIFT, FGP_LOCK, 0);
-	if (folio) {
-		same_folio = lend < folio_pos(folio) + folio_size(folio);
+	if (!IS_ERR(folio)) {
+		same_folio = lend < folio_next_pos(folio);
 		if (!truncate_inode_partial_folio(folio, lstart, lend)) {
-			start = folio->index + folio_nr_pages(folio);
+			start = folio_next_index(folio);
 			if (same_folio)
 				end = folio->index;
 		}
@@ -387,14 +423,15 @@ void truncate_inode_pages_range(struct address_space *mapping,
 		folio = NULL;
 	}
 
-	if (!same_folio)
+	if (!same_folio) {
 		folio = __filemap_get_folio(mapping, lend >> PAGE_SHIFT,
 						FGP_LOCK, 0);
-	if (folio) {
-		if (!truncate_inode_partial_folio(folio, lstart, lend))
-			end = folio->index;
-		folio_unlock(folio);
-		folio_put(folio);
+		if (!IS_ERR(folio)) {
+			if (!truncate_inode_partial_folio(folio, lstart, lend))
+				end = folio->index;
+			folio_unlock(folio);
+			folio_put(folio);
+		}
 	}
 
 	index = start;
@@ -413,7 +450,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 		for (i = 0; i < folio_batch_count(&fbatch); i++) {
 			struct folio *folio = fbatch.folios[i];
 
-			/* We rely upon deletion not changing page->index */
+			/* We rely upon deletion not changing folio->index */
 
 			if (xa_is_value(folio))
 				continue;
@@ -485,18 +522,17 @@ void truncate_inode_pages_final(struct address_space *mapping)
 EXPORT_SYMBOL(truncate_inode_pages_final);
 
 /**
- * invalidate_mapping_pagevec - Invalidate all the unlocked pages of one inode
- * @mapping: the address_space which holds the pages to invalidate
+ * mapping_try_invalidate - Invalidate all the evictable folios of one inode
+ * @mapping: the address_space which holds the folios to invalidate
  * @start: the offset 'from' which to invalidate
  * @end: the offset 'to' which to invalidate (inclusive)
- * @nr_pagevec: invalidate failed page number for caller
+ * @nr_failed: How many folio invalidations failed
  *
- * This helper is similar to invalidate_mapping_pages(), except that it accounts
- * for pages that are likely on a pagevec and counts them in @nr_pagevec, which
- * will be used by the caller.
+ * This function is similar to invalidate_mapping_pages(), except that it
+ * returns the number of folios which could not be evicted in @nr_failed.
  */
-unsigned long invalidate_mapping_pagevec(struct address_space *mapping,
-		pgoff_t start, pgoff_t end, unsigned long *nr_pagevec)
+unsigned long mapping_try_invalidate(struct address_space *mapping,
+		pgoff_t start, pgoff_t end, unsigned long *nr_failed)
 {
 	pgoff_t indices[PAGEVEC_SIZE];
 	struct folio_batch fbatch;
@@ -507,14 +543,17 @@ unsigned long invalidate_mapping_pagevec(struct address_space *mapping,
 
 	folio_batch_init(&fbatch);
 	while (find_lock_entries(mapping, &index, end, &fbatch, indices)) {
-		for (i = 0; i < folio_batch_count(&fbatch); i++) {
+		bool xa_has_values = false;
+		int nr = folio_batch_count(&fbatch);
+
+		for (i = 0; i < nr; i++) {
 			struct folio *folio = fbatch.folios[i];
 
 			/* We rely upon deletion not changing folio->index */
 
 			if (xa_is_value(folio)) {
-				count += invalidate_exceptional_entry(mapping,
-							     indices[i], folio);
+				xa_has_values = true;
+				count++;
 				continue;
 			}
 
@@ -526,12 +565,16 @@ unsigned long invalidate_mapping_pagevec(struct address_space *mapping,
 			 */
 			if (!ret) {
 				deactivate_file_folio(folio);
-				/* It is likely on the pagevec of a remote CPU */
-				if (nr_pagevec)
-					(*nr_pagevec)++;
+				/* Likely in the lru cache of a remote CPU */
+				if (nr_failed)
+					(*nr_failed)++;
 			}
 			count += ret;
 		}
+
+		if (xa_has_values)
+			clear_shadow_entries(mapping, indices[0], indices[nr-1]);
+
 		folio_batch_remove_exceptionals(&fbatch);
 		folio_batch_release(&fbatch);
 		cond_resched();
@@ -551,31 +594,49 @@ unsigned long invalidate_mapping_pagevec(struct address_space *mapping,
  * If you want to remove all the pages of one inode, regardless of
  * their use and writeback state, use truncate_inode_pages().
  *
- * Return: the number of the cache entries that were invalidated
+ * Return: The number of indices that had their contents invalidated
  */
 unsigned long invalidate_mapping_pages(struct address_space *mapping,
 		pgoff_t start, pgoff_t end)
 {
-	return invalidate_mapping_pagevec(mapping, start, end, NULL);
+	return mapping_try_invalidate(mapping, start, end, NULL);
 }
 EXPORT_SYMBOL(invalidate_mapping_pages);
 
+static int folio_launder(struct address_space *mapping, struct folio *folio)
+{
+	if (!folio_test_dirty(folio))
+		return 0;
+	if (folio->mapping != mapping || mapping->a_ops->launder_folio == NULL)
+		return 0;
+	return mapping->a_ops->launder_folio(folio);
+}
+
 /*
- * This is like invalidate_inode_page(), except it ignores the page's
+ * This is like mapping_evict_folio(), except it ignores the folio's
  * refcount.  We do this because invalidate_inode_pages2() needs stronger
- * invalidation guarantees, and cannot afford to leave pages behind because
- * shrink_page_list() has a temp ref on them, or because they're transiently
- * sitting in the folio_add_lru() pagevecs.
+ * invalidation guarantees, and cannot afford to leave folios behind because
+ * shrink_folio_list() has a temp ref on them, or because they're transiently
+ * sitting in the folio_add_lru() caches.
  */
-static int invalidate_complete_folio2(struct address_space *mapping,
-					struct folio *folio)
+int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio,
+			   gfp_t gfp)
 {
-	if (folio->mapping != mapping)
-		return 0;
+	int ret;
 
-	if (folio_has_private(folio) &&
-	    !filemap_release_folio(folio, GFP_KERNEL))
-		return 0;
+	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
+
+	if (folio_mapped(folio))
+		unmap_mapping_folio(folio);
+	BUG_ON(folio_mapped(folio));
+
+	ret = folio_launder(mapping, folio);
+	if (ret)
+		return ret;
+	if (folio->mapping != mapping)
+		return -EBUSY;
+	if (!filemap_release_folio(folio, gfp))
+		return -EBUSY;
 
 	spin_lock(&mapping->host->i_lock);
 	xa_lock_irq(&mapping->i_pages);
@@ -586,7 +647,7 @@ static int invalidate_complete_folio2(struct address_space *mapping,
 	__filemap_remove_folio(folio, NULL);
 	xa_unlock_irq(&mapping->i_pages);
 	if (mapping_shrinkable(mapping))
-		inode_add_lru(mapping->host);
+		inode_lru_list_add(mapping->host);
 	spin_unlock(&mapping->host->i_lock);
 
 	filemap_free_folio(mapping, folio);
@@ -594,16 +655,7 @@ static int invalidate_complete_folio2(struct address_space *mapping,
 failed:
 	xa_unlock_irq(&mapping->i_pages);
 	spin_unlock(&mapping->host->i_lock);
-	return 0;
-}
-
-static int folio_launder(struct address_space *mapping, struct folio *folio)
-{
-	if (!folio_test_dirty(folio))
-		return 0;
-	if (folio->mapping != mapping || mapping->a_ops->launder_folio == NULL)
-		return 0;
-	return mapping->a_ops->launder_folio(folio);
+	return -EBUSY;
 }
 
 /**
@@ -634,14 +686,18 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 	folio_batch_init(&fbatch);
 	index = start;
 	while (find_get_entries(mapping, &index, end, &fbatch, indices)) {
-		for (i = 0; i < folio_batch_count(&fbatch); i++) {
+		bool xa_has_values = false;
+		int nr = folio_batch_count(&fbatch);
+
+		for (i = 0; i < nr; i++) {
 			struct folio *folio = fbatch.folios[i];
 
 			/* We rely upon deletion not changing folio->index */
 
 			if (xa_is_value(folio)) {
-				if (!invalidate_exceptional_entry2(mapping,
-						indices[i], folio))
+				xa_has_values = true;
+				if (dax_mapping(mapping) &&
+				    !dax_invalidate_mapping_entry_sync(mapping, indices[i]))
 					ret = -EBUSY;
 				continue;
 			}
@@ -657,26 +713,21 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 			}
 
 			folio_lock(folio);
-			VM_BUG_ON_FOLIO(!folio_contains(folio, indices[i]), folio);
-			if (folio->mapping != mapping) {
+			if (unlikely(folio->mapping != mapping)) {
 				folio_unlock(folio);
 				continue;
 			}
+			VM_BUG_ON_FOLIO(!folio_contains(folio, indices[i]), folio);
 			folio_wait_writeback(folio);
-
-			if (folio_mapped(folio))
-				unmap_mapping_folio(folio);
-			BUG_ON(folio_mapped(folio));
-
-			ret2 = folio_launder(mapping, folio);
-			if (ret2 == 0) {
-				if (!invalidate_complete_folio2(mapping, folio))
-					ret2 = -EBUSY;
-			}
+			ret2 = folio_unmap_invalidate(mapping, folio, GFP_KERNEL);
 			if (ret2 < 0)
 				ret = ret2;
 			folio_unlock(folio);
 		}
+
+		if (xa_has_values)
+			clear_shadow_entries(mapping, indices[0], indices[nr-1]);
+
 		folio_batch_remove_exceptionals(&fbatch);
 		folio_batch_release(&fbatch);
 		cond_resched();
@@ -775,15 +826,15 @@ EXPORT_SYMBOL(truncate_setsize);
  * @from:	original inode size
  * @to:		new inode size
  *
- * Handle extension of inode size either caused by extending truncate or by
- * write starting after current i_size. We mark the page straddling current
- * i_size RO so that page_mkwrite() is called on the nearest write access to
- * the page.  This way filesystem can be sure that page_mkwrite() is called on
- * the page before user writes to the page via mmap after the i_size has been
- * changed.
+ * Handle extension of inode size either caused by extending truncate or
+ * by write starting after current i_size.  We mark the page straddling
+ * current i_size RO so that page_mkwrite() is called on the first
+ * write access to the page.  The filesystem will update its per-block
+ * information before user writes to the page via mmap after the i_size
+ * has been changed.
  *
  * The function must be called after i_size is updated so that page fault
- * coming after we unlock the page will already see the new i_size.
+ * coming after we unlock the folio will already see the new i_size.
  * The function must be called while we still hold i_rwsem - this not only
  * makes sure i_size is stable but also that userspace cannot observe new
  * i_size value before we are prepared to store mmap writes at new inode size.
@@ -792,31 +843,44 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
 {
 	int bsize = i_blocksize(inode);
 	loff_t rounded_from;
-	struct page *page;
-	pgoff_t index;
+	struct folio *folio;
 
 	WARN_ON(to > inode->i_size);
 
-	if (from >= to || bsize == PAGE_SIZE)
+	if (from >= to || bsize >= PAGE_SIZE)
 		return;
 	/* Page straddling @from will not have any hole block created? */
 	rounded_from = round_up(from, bsize);
 	if (to <= rounded_from || !(rounded_from & (PAGE_SIZE - 1)))
 		return;
 
-	index = from >> PAGE_SHIFT;
-	page = find_lock_page(inode->i_mapping, index);
-	/* Page not cached? Nothing to do */
-	if (!page)
+	folio = filemap_lock_folio(inode->i_mapping, from / PAGE_SIZE);
+	/* Folio not cached? Nothing to do */
+	if (IS_ERR(folio))
 		return;
 	/*
-	 * See clear_page_dirty_for_io() for details why set_page_dirty()
+	 * See folio_clear_dirty_for_io() for details why folio_mark_dirty()
 	 * is needed.
 	 */
-	if (page_mkclean(page))
-		set_page_dirty(page);
-	unlock_page(page);
-	put_page(page);
+	if (folio_mkclean(folio))
+		folio_mark_dirty(folio);
+
+	/*
+	 * The post-eof range of the folio must be zeroed before it is exposed
+	 * to the file. Writeback normally does this, but since i_size has been
+	 * increased we handle it here.
+	 */
+	if (folio_test_dirty(folio)) {
+		unsigned int offset, end;
+
+		offset = from - folio_pos(folio);
+		end = min_t(unsigned int, to - folio_pos(folio),
+			    folio_size(folio));
+		folio_zero_segment(folio, offset, end);
+	}
+
+	folio_unlock(folio);
+	folio_put(folio);
 }
 EXPORT_SYMBOL(pagecache_isize_extended);