1 files changed, 154 insertions, 116 deletions

diff --git a/fs/dax.c b/fs/dax.c
index 0276df90e86c..aaec72ded1b6 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -73,16 +73,15 @@ fs_initcall(init_dax_wait_table);
 #define RADIX_DAX_ZERO_PAGE	(1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
 #define RADIX_DAX_EMPTY		(1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3))
 
-static unsigned long dax_radix_sector(void *entry)
+static unsigned long dax_radix_pfn(void *entry)
 {
 	return (unsigned long)entry >> RADIX_DAX_SHIFT;
 }
 
-static void *dax_radix_locked_entry(sector_t sector, unsigned long flags)
+static void *dax_radix_locked_entry(unsigned long pfn, unsigned long flags)
 {
 	return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags |
-			((unsigned long)sector << RADIX_DAX_SHIFT) |
-			RADIX_DAX_ENTRY_LOCK);
+			(pfn << RADIX_DAX_SHIFT) | RADIX_DAX_ENTRY_LOCK);
 }
 
 static unsigned int dax_radix_order(void *entry)
@@ -159,11 +158,9 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo
 }
 
 /*
- * We do not necessarily hold the mapping->tree_lock when we call this
- * function so it is possible that 'entry' is no longer a valid item in the
- * radix tree.  This is okay because all we really need to do is to find the
- * correct waitqueue where tasks might be waiting for that old 'entry' and
- * wake them.
+ * @entry may no longer be the entry at the index in the mapping.
+ * The important information it's conveying is whether the entry at
+ * this index used to be a PMD entry.
  */
 static void dax_wake_mapping_entry_waiter(struct address_space *mapping,
 		pgoff_t index, void *entry, bool wake_all)
@@ -175,7 +172,7 @@ static void dax_wake_mapping_entry_waiter(struct address_space *mapping,
 
 	/*
 	 * Checking for locked entry and prepare_to_wait_exclusive() happens
-	 * under mapping->tree_lock, ditto for entry handling in our callers.
+	 * under the i_pages lock, ditto for entry handling in our callers.
 	 * So at this point all tasks that could have seen our entry locked
 	 * must be in the waitqueue and the following check will see them.
 	 */
@@ -184,41 +181,39 @@ static void dax_wake_mapping_entry_waiter(struct address_space *mapping,
 }
 
 /*
- * Check whether the given slot is locked. The function must be called with
- * mapping->tree_lock held
+ * Check whether the given slot is locked.  Must be called with the i_pages
+ * lock held.
  */
 static inline int slot_locked(struct address_space *mapping, void **slot)
 {
 	unsigned long entry = (unsigned long)
-		radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
+		radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
 	return entry & RADIX_DAX_ENTRY_LOCK;
 }
 
 /*
- * Mark the given slot is locked. The function must be called with
- * mapping->tree_lock held
+ * Mark the given slot as locked.  Must be called with the i_pages lock held.
  */
 static inline void *lock_slot(struct address_space *mapping, void **slot)
 {
 	unsigned long entry = (unsigned long)
-		radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
+		radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
 
 	entry |= RADIX_DAX_ENTRY_LOCK;
-	radix_tree_replace_slot(&mapping->page_tree, slot, (void *)entry);
+	radix_tree_replace_slot(&mapping->i_pages, slot, (void *)entry);
 	return (void *)entry;
 }
 
 /*
- * Mark the given slot is unlocked. The function must be called with
- * mapping->tree_lock held
+ * Mark the given slot as unlocked.  Must be called with the i_pages lock held.
  */
 static inline void *unlock_slot(struct address_space *mapping, void **slot)
 {
 	unsigned long entry = (unsigned long)
-		radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
+		radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
 
 	entry &= ~(unsigned long)RADIX_DAX_ENTRY_LOCK;
-	radix_tree_replace_slot(&mapping->page_tree, slot, (void *)entry);
+	radix_tree_replace_slot(&mapping->i_pages, slot, (void *)entry);
 	return (void *)entry;
 }
 
@@ -229,7 +224,7 @@ static inline void *unlock_slot(struct address_space *mapping, void **slot)
  * put_locked_mapping_entry() when he locked the entry and now wants to
  * unlock it.
  *
- * The function must be called with mapping->tree_lock held.
+ * Must be called with the i_pages lock held.
  */
 static void *get_unlocked_mapping_entry(struct address_space *mapping,
 					pgoff_t index, void ***slotp)
@@ -242,7 +237,7 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping,
 	ewait.wait.func = wake_exceptional_entry_func;
 
 	for (;;) {
-		entry = __radix_tree_lookup(&mapping->page_tree, index, NULL,
+		entry = __radix_tree_lookup(&mapping->i_pages, index, NULL,
 					  &slot);
 		if (!entry ||
 		    WARN_ON_ONCE(!radix_tree_exceptional_entry(entry)) ||
@@ -255,10 +250,10 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping,
 		wq = dax_entry_waitqueue(mapping, index, entry, &ewait.key);
 		prepare_to_wait_exclusive(wq, &ewait.wait,
 					  TASK_UNINTERRUPTIBLE);
-		spin_unlock_irq(&mapping->tree_lock);
+		xa_unlock_irq(&mapping->i_pages);
 		schedule();
 		finish_wait(wq, &ewait.wait);
-		spin_lock_irq(&mapping->tree_lock);
+		xa_lock_irq(&mapping->i_pages);
 	}
 }
 
@@ -267,15 +262,15 @@ static void dax_unlock_mapping_entry(struct address_space *mapping,
 {
 	void *entry, **slot;
 
-	spin_lock_irq(&mapping->tree_lock);
-	entry = __radix_tree_lookup(&mapping->page_tree, index, NULL, &slot);
+	xa_lock_irq(&mapping->i_pages);
+	entry = __radix_tree_lookup(&mapping->i_pages, index, NULL, &slot);
 	if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) ||
 			 !slot_locked(mapping, slot))) {
-		spin_unlock_irq(&mapping->tree_lock);
+		xa_unlock_irq(&mapping->i_pages);
 		return;
 	}
 	unlock_slot(mapping, slot);
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_unlock_irq(&mapping->i_pages);
 	dax_wake_mapping_entry_waiter(mapping, index, entry, false);
 }
 
@@ -299,6 +294,63 @@ static void put_unlocked_mapping_entry(struct address_space *mapping,
 	dax_wake_mapping_entry_waiter(mapping, index, entry, false);
 }
 
+static unsigned long dax_entry_size(void *entry)
+{
+	if (dax_is_zero_entry(entry))
+		return 0;
+	else if (dax_is_empty_entry(entry))
+		return 0;
+	else if (dax_is_pmd_entry(entry))
+		return PMD_SIZE;
+	else
+		return PAGE_SIZE;
+}
+
+static unsigned long dax_radix_end_pfn(void *entry)
+{
+	return dax_radix_pfn(entry) + dax_entry_size(entry) / PAGE_SIZE;
+}
+
+/*
+ * Iterate through all mapped pfns represented by an entry, i.e. skip
+ * 'empty' and 'zero' entries.
+ */
+#define for_each_mapped_pfn(entry, pfn) \
+	for (pfn = dax_radix_pfn(entry); \
+			pfn < dax_radix_end_pfn(entry); pfn++)
+
+static void dax_associate_entry(void *entry, struct address_space *mapping)
+{
+	unsigned long pfn;
+
+	if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
+		return;
+
+	for_each_mapped_pfn(entry, pfn) {
+		struct page *page = pfn_to_page(pfn);
+
+		WARN_ON_ONCE(page->mapping);
+		page->mapping = mapping;
+	}
+}
+
+static void dax_disassociate_entry(void *entry, struct address_space *mapping,
+		bool trunc)
+{
+	unsigned long pfn;
+
+	if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
+		return;
+
+	for_each_mapped_pfn(entry, pfn) {
+		struct page *page = pfn_to_page(pfn);
+
+		WARN_ON_ONCE(trunc && page_ref_count(page) > 1);
+		WARN_ON_ONCE(page->mapping && page->mapping != mapping);
+		page->mapping = NULL;
+	}
+}
+
 /*
  * Find radix tree entry at given index. If it points to an exceptional entry,
  * return it with the radix tree entry locked. If the radix tree doesn't
@@ -332,7 +384,7 @@ static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
 	void *entry, **slot;
 
 restart:
-	spin_lock_irq(&mapping->tree_lock);
+	xa_lock_irq(&mapping->i_pages);
 	entry = get_unlocked_mapping_entry(mapping, index, &slot);
 
 	if (WARN_ON_ONCE(entry && !radix_tree_exceptional_entry(entry))) {
@@ -364,12 +416,12 @@ restart:
 		if (pmd_downgrade) {
 			/*
 			 * Make sure 'entry' remains valid while we drop
-			 * mapping->tree_lock.
+			 * the i_pages lock.
 			 */
 			entry = lock_slot(mapping, slot);
 		}
 
-		spin_unlock_irq(&mapping->tree_lock);
+		xa_unlock_irq(&mapping->i_pages);
 		/*
 		 * Besides huge zero pages the only other thing that gets
 		 * downgraded are empty entries which don't need to be
@@ -386,26 +438,27 @@ restart:
 				put_locked_mapping_entry(mapping, index);
 			return ERR_PTR(err);
 		}
-		spin_lock_irq(&mapping->tree_lock);
+		xa_lock_irq(&mapping->i_pages);
 
 		if (!entry) {
 			/*
-			 * We needed to drop the page_tree lock while calling
+			 * We needed to drop the i_pages lock while calling
 			 * radix_tree_preload() and we didn't have an entry to
 			 * lock.  See if another thread inserted an entry at
 			 * our index during this time.
 			 */
-			entry = __radix_tree_lookup(&mapping->page_tree, index,
+			entry = __radix_tree_lookup(&mapping->i_pages, index,
 					NULL, &slot);
 			if (entry) {
 				radix_tree_preload_end();
-				spin_unlock_irq(&mapping->tree_lock);
+				xa_unlock_irq(&mapping->i_pages);
 				goto restart;
 			}
 		}
 
 		if (pmd_downgrade) {
-			radix_tree_delete(&mapping->page_tree, index);
+			dax_disassociate_entry(entry, mapping, false);
+			radix_tree_delete(&mapping->i_pages, index);
 			mapping->nrexceptional--;
 			dax_wake_mapping_entry_waiter(mapping, index, entry,
 					true);
@@ -413,11 +466,11 @@ restart:
 
 		entry = dax_radix_locked_entry(0, size_flag | RADIX_DAX_EMPTY);
 
-		err = __radix_tree_insert(&mapping->page_tree, index,
+		err = __radix_tree_insert(&mapping->i_pages, index,
 				dax_radix_order(entry), entry);
 		radix_tree_preload_end();
 		if (err) {
-			spin_unlock_irq(&mapping->tree_lock);
+			xa_unlock_irq(&mapping->i_pages);
 			/*
 			 * Our insertion of a DAX entry failed, most likely
 			 * because we were inserting a PMD entry and it
@@ -430,12 +483,12 @@ restart:
 		}
 		/* Good, we have inserted empty locked entry into the tree. */
 		mapping->nrexceptional++;
-		spin_unlock_irq(&mapping->tree_lock);
+		xa_unlock_irq(&mapping->i_pages);
 		return entry;
 	}
 	entry = lock_slot(mapping, slot);
  out_unlock:
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_unlock_irq(&mapping->i_pages);
 	return entry;
 }
 
@@ -444,22 +497,23 @@ static int __dax_invalidate_mapping_entry(struct address_space *mapping,
 {
 	int ret = 0;
 	void *entry;
-	struct radix_tree_root *page_tree = &mapping->page_tree;
+	struct radix_tree_root *pages = &mapping->i_pages;
 
-	spin_lock_irq(&mapping->tree_lock);
+	xa_lock_irq(pages);
 	entry = get_unlocked_mapping_entry(mapping, index, NULL);
 	if (!entry || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry)))
 		goto out;
 	if (!trunc &&
-	    (radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_DIRTY) ||
-	     radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE)))
+	    (radix_tree_tag_get(pages, index, PAGECACHE_TAG_DIRTY) ||
+	     radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE)))
 		goto out;
-	radix_tree_delete(page_tree, index);
+	dax_disassociate_entry(entry, mapping, trunc);
+	radix_tree_delete(pages, index);
 	mapping->nrexceptional--;
 	ret = 1;
 out:
 	put_unlocked_mapping_entry(mapping, index, entry);
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_unlock_irq(pages);
 	return ret;
 }
 /*
@@ -526,12 +580,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
  */
 static void *dax_insert_mapping_entry(struct address_space *mapping,
 				      struct vm_fault *vmf,
-				      void *entry, sector_t sector,
+				      void *entry, pfn_t pfn_t,
 				      unsigned long flags, bool dirty)
 {
-	struct radix_tree_root *page_tree = &mapping->page_tree;
-	void *new_entry;
+	struct radix_tree_root *pages = &mapping->i_pages;
+	unsigned long pfn = pfn_t_to_pfn(pfn_t);
 	pgoff_t index = vmf->pgoff;
+	void *new_entry;
 
 	if (dirty)
 		__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
@@ -545,8 +600,12 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
 			unmap_mapping_pages(mapping, vmf->pgoff, 1, false);
 	}
 
-	spin_lock_irq(&mapping->tree_lock);
-	new_entry = dax_radix_locked_entry(sector, flags);
+	xa_lock_irq(pages);
+	new_entry = dax_radix_locked_entry(pfn, flags);
+	if (dax_entry_size(entry) != dax_entry_size(new_entry)) {
+		dax_disassociate_entry(entry, mapping, false);
+		dax_associate_entry(new_entry, mapping);
+	}
 
 	if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) {
 		/*
@@ -561,17 +620,17 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
 		void **slot;
 		void *ret;
 
-		ret = __radix_tree_lookup(page_tree, index, &node, &slot);
+		ret = __radix_tree_lookup(pages, index, &node, &slot);
 		WARN_ON_ONCE(ret != entry);
-		__radix_tree_replace(page_tree, node, slot,
+		__radix_tree_replace(pages, node, slot,
 				     new_entry, NULL);
 		entry = new_entry;
 	}
 
 	if (dirty)
-		radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
+		radix_tree_tag_set(pages, index, PAGECACHE_TAG_DIRTY);
 
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_unlock_irq(pages);
 	return entry;
 }
 
@@ -657,17 +716,14 @@ unlock_pte:
 	i_mmap_unlock_read(mapping);
 }
 
-static int dax_writeback_one(struct block_device *bdev,
-		struct dax_device *dax_dev, struct address_space *mapping,
-		pgoff_t index, void *entry)
+static int dax_writeback_one(struct dax_device *dax_dev,
+		struct address_space *mapping, pgoff_t index, void *entry)
 {
-	struct radix_tree_root *page_tree = &mapping->page_tree;
-	void *entry2, **slot, *kaddr;
-	long ret = 0, id;
-	sector_t sector;
-	pgoff_t pgoff;
+	struct radix_tree_root *pages = &mapping->i_pages;
+	void *entry2, **slot;
+	unsigned long pfn;
+	long ret = 0;
 	size_t size;
-	pfn_t pfn;
 
 	/*
 	 * A page got tagged dirty in DAX mapping? Something is seriously
@@ -676,17 +732,17 @@ static int dax_writeback_one(struct block_device *bdev,
 	if (WARN_ON(!radix_tree_exceptional_entry(entry)))
 		return -EIO;
 
-	spin_lock_irq(&mapping->tree_lock);
+	xa_lock_irq(pages);
 	entry2 = get_unlocked_mapping_entry(mapping, index, &slot);
 	/* Entry got punched out / reallocated? */
 	if (!entry2 || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry2)))
 		goto put_unlocked;
 	/*
 	 * Entry got reallocated elsewhere? No need to writeback. We have to
-	 * compare sectors as we must not bail out due to difference in lockbit
+	 * compare pfns as we must not bail out due to difference in lockbit
 	 * or entry type.
 	 */
-	if (dax_radix_sector(entry2) != dax_radix_sector(entry))
+	if (dax_radix_pfn(entry2) != dax_radix_pfn(entry))
 		goto put_unlocked;
 	if (WARN_ON_ONCE(dax_is_empty_entry(entry) ||
 				dax_is_zero_entry(entry))) {
@@ -695,7 +751,7 @@ static int dax_writeback_one(struct block_device *bdev,
 	}
 
 	/* Another fsync thread may have already written back this entry */
-	if (!radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
+	if (!radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE))
 		goto put_unlocked;
 	/* Lock the entry to serialize with page faults */
 	entry = lock_slot(mapping, slot);
@@ -703,60 +759,40 @@ static int dax_writeback_one(struct block_device *bdev,
 	 * We can clear the tag now but we have to be careful so that concurrent
 	 * dax_writeback_one() calls for the same index cannot finish before we
 	 * actually flush the caches. This is achieved as the calls will look
-	 * at the entry only under tree_lock and once they do that they will
-	 * see the entry locked and wait for it to unlock.
+	 * at the entry only under the i_pages lock and once they do that
+	 * they will see the entry locked and wait for it to unlock.
 	 */
-	radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_TOWRITE);
-	spin_unlock_irq(&mapping->tree_lock);
+	radix_tree_tag_clear(pages, index, PAGECACHE_TAG_TOWRITE);
+	xa_unlock_irq(pages);
 
 	/*
 	 * Even if dax_writeback_mapping_range() was given a wbc->range_start
 	 * in the middle of a PMD, the 'index' we are given will be aligned to
-	 * the start index of the PMD, as will the sector we pull from
-	 * 'entry'.  This allows us to flush for PMD_SIZE and not have to
-	 * worry about partial PMD writebacks.
+	 * the start index of the PMD, as will the pfn we pull from 'entry'.
+	 * This allows us to flush for PMD_SIZE and not have to worry about
+	 * partial PMD writebacks.
 	 */
-	sector = dax_radix_sector(entry);
+	pfn = dax_radix_pfn(entry);
 	size = PAGE_SIZE << dax_radix_order(entry);
 
-	id = dax_read_lock();
-	ret = bdev_dax_pgoff(bdev, sector, size, &pgoff);
-	if (ret)
-		goto dax_unlock;
-
-	/*
-	 * dax_direct_access() may sleep, so cannot hold tree_lock over
-	 * its invocation.
-	 */
-	ret = dax_direct_access(dax_dev, pgoff, size / PAGE_SIZE, &kaddr, &pfn);
-	if (ret < 0)
-		goto dax_unlock;
-
-	if (WARN_ON_ONCE(ret < size / PAGE_SIZE)) {
-		ret = -EIO;
-		goto dax_unlock;
-	}
-
-	dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(pfn));
-	dax_flush(dax_dev, kaddr, size);
+	dax_mapping_entry_mkclean(mapping, index, pfn);
+	dax_flush(dax_dev, page_address(pfn_to_page(pfn)), size);
 	/*
 	 * After we have flushed the cache, we can clear the dirty tag. There
 	 * cannot be new dirty data in the pfn after the flush has completed as
 	 * the pfn mappings are writeprotected and fault waits for mapping
 	 * entry lock.
 	 */
-	spin_lock_irq(&mapping->tree_lock);
-	radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_DIRTY);
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_lock_irq(pages);
+	radix_tree_tag_clear(pages, index, PAGECACHE_TAG_DIRTY);
+	xa_unlock_irq(pages);
 	trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT);
- dax_unlock:
-	dax_read_unlock(id);
 	put_locked_mapping_entry(mapping, index);
 	return ret;
 
  put_unlocked:
 	put_unlocked_mapping_entry(mapping, index, entry2);
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_unlock_irq(pages);
 	return ret;
 }
 
@@ -808,8 +844,8 @@ int dax_writeback_mapping_range(struct address_space *mapping,
 				break;
 			}
 
-			ret = dax_writeback_one(bdev, dax_dev, mapping,
-					indices[i], pvec.pages[i]);
+			ret = dax_writeback_one(dax_dev, mapping, indices[i],
+					pvec.pages[i]);
 			if (ret < 0) {
 				mapping_set_error(mapping, ret);
 				goto out;
@@ -877,6 +913,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
 	int ret = VM_FAULT_NOPAGE;
 	struct page *zero_page;
 	void *entry2;
+	pfn_t pfn;
 
 	zero_page = ZERO_PAGE(0);
 	if (unlikely(!zero_page)) {
@@ -884,14 +921,15 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
 		goto out;
 	}
 
-	entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
+	pfn = page_to_pfn_t(zero_page);
+	entry2 = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
 			RADIX_DAX_ZERO_PAGE, false);
 	if (IS_ERR(entry2)) {
 		ret = VM_FAULT_SIGBUS;
 		goto out;
 	}
 
-	vm_insert_mixed(vmf->vma, vaddr, page_to_pfn_t(zero_page));
+	vm_insert_mixed(vmf->vma, vaddr, pfn);
 out:
 	trace_dax_load_hole(inode, vmf, ret);
 	return ret;
@@ -1200,8 +1238,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
 		if (error < 0)
 			goto error_finish_iomap;
 
-		entry = dax_insert_mapping_entry(mapping, vmf, entry,
-						 dax_iomap_sector(&iomap, pos),
+		entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
 						 0, write && !sync);
 		if (IS_ERR(entry)) {
 			error = PTR_ERR(entry);
@@ -1280,13 +1317,15 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
 	void *ret = NULL;
 	spinlock_t *ptl;
 	pmd_t pmd_entry;
+	pfn_t pfn;
 
 	zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm);
 
 	if (unlikely(!zero_page))
 		goto fallback;
 
-	ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
+	pfn = page_to_pfn_t(zero_page);
+	ret = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
 			RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
 	if (IS_ERR(ret))
 		goto fallback;
@@ -1409,8 +1448,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
 		if (error < 0)
 			goto finish_iomap;
 
-		entry = dax_insert_mapping_entry(mapping, vmf, entry,
-						dax_iomap_sector(&iomap, pos),
+		entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
 						RADIX_DAX_PMD, write && !sync);
 		if (IS_ERR(entry))
 			goto finish_iomap;
@@ -1524,21 +1562,21 @@ static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
 	pgoff_t index = vmf->pgoff;
 	int vmf_ret, error;
 
-	spin_lock_irq(&mapping->tree_lock);
+	xa_lock_irq(&mapping->i_pages);
 	entry = get_unlocked_mapping_entry(mapping, index, &slot);
 	/* Did we race with someone splitting entry or so? */
 	if (!entry ||
 	    (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) ||
 	    (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) {
 		put_unlocked_mapping_entry(mapping, index, entry);
-		spin_unlock_irq(&mapping->tree_lock);
+		xa_unlock_irq(&mapping->i_pages);
 		trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
 						      VM_FAULT_NOPAGE);
 		return VM_FAULT_NOPAGE;
 	}
-	radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
+	radix_tree_tag_set(&mapping->i_pages, index, PAGECACHE_TAG_DIRTY);
 	entry = lock_slot(mapping, slot);
-	spin_unlock_irq(&mapping->tree_lock);
+	xa_unlock_irq(&mapping->i_pages);
 	switch (pe_size) {
 	case PE_SIZE_PTE:
 		error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);