7 files changed, 43 insertions, 16 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 31c6d1090f11..826b164a4b5b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1697,13 +1697,24 @@ static int blkdev_releasepage(struct page *page, gfp_t wait)
         return try_to_free_buffers(page);
 }
 
+static int blkdev_writepages(struct address_space *mapping,
+                             struct writeback_control *wbc)
+{
+        if (dax_mapping(mapping)) {
+                struct block_device *bdev = I_BDEV(mapping->host);
+
+                return dax_writeback_mapping_range(mapping, bdev, wbc);
+        }
+        return generic_writepages(mapping, wbc);
+}
+
 static const struct address_space_operations def_blk_aops = {
         .readpage       = blkdev_readpage,
         .readpages      = blkdev_readpages,
         .writepage      = blkdev_writepage,
         .write_begin    = blkdev_write_begin,
         .write_end      = blkdev_write_end,
-        .writepages     = generic_writepages,
+        .writepages     = blkdev_writepages,
         .releasepage    = blkdev_releasepage,
         .direct_IO      = blkdev_direct_IO,
         .is_dirty_writeback = buffer_check_dirty_writeback,
diff --git a/fs/dax.c b/fs/dax.c
index 9a173dd8c4a3..711172450da6 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -484,11 +484,10 @@ static int dax_writeback_one(struct block_device *bdev,
  * end]. This is required by data integrity operations to ensure file data is
  * on persistent storage prior to completion of the operation.
  */
-int dax_writeback_mapping_range(struct address_space *mapping, loff_t start,
-                loff_t end)
+int dax_writeback_mapping_range(struct address_space *mapping,
+                struct block_device *bdev, struct writeback_control *wbc)
 {
         struct inode *inode = mapping->host;
-        struct block_device *bdev = inode->i_sb->s_bdev;
         pgoff_t start_index, end_index, pmd_index;
         pgoff_t indices[PAGEVEC_SIZE];
         struct pagevec pvec;
@@ -499,8 +498,11 @@ int dax_writeback_mapping_range(struct address_space *mapping, loff_t start,
         if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
                 return -EIO;
 
-        start_index = start >> PAGE_CACHE_SHIFT;
-        end_index = end >> PAGE_CACHE_SHIFT;
+        if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL)
+                return 0;
+
+        start_index = wbc->range_start >> PAGE_CACHE_SHIFT;
+        end_index = wbc->range_end >> PAGE_CACHE_SHIFT;
         pmd_index = DAX_PMD_INDEX(start_index);
 
         rcu_read_lock();
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 4467cbd75f24..6bd58e6ff038 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -876,6 +876,14 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
 static int
 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
 {
+#ifdef CONFIG_FS_DAX
+        if (dax_mapping(mapping)) {
+                return dax_writeback_mapping_range(mapping,
+                                                   mapping->host->i_sb->s_bdev,
+                                                   wbc);
+        }
+#endif
+
         return mpage_writepages(mapping, wbc, ext2_get_block);
 }
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5708e689e63d..aee960b1af34 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2478,6 +2478,10 @@ static int ext4_writepages(struct address_space *mapping,
 
         trace_ext4_writepages(inode, wbc);
 
+        if (dax_mapping(mapping))
+                return dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev,
+                                                   wbc);
+
         /*
          * No pages to write? This is mainly a kludge to avoid starting
          * a transaction for special inodes like journal inode on last iput()
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index fc20518e2398..a9ebabfe7587 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1208,6 +1208,10 @@ xfs_vm_writepages(
         struct writeback_control *wbc)
 {
         xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
+        if (dax_mapping(mapping))
+                return dax_writeback_mapping_range(mapping,
+                                xfs_find_bdev_for_inode(mapping->host), wbc);
+
         return generic_writepages(mapping, wbc);
 }
 
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 7b6bcedb980f..636dd59ab505 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -52,6 +52,8 @@ static inline bool dax_mapping(struct address_space *mapping)
 {
         return mapping->host && IS_DAX(mapping->host);
 }
-int dax_writeback_mapping_range(struct address_space *mapping, loff_t start,
-                loff_t end);
+
+struct writeback_control;
+int dax_writeback_mapping_range(struct address_space *mapping,
+                struct block_device *bdev, struct writeback_control *wbc);
 #endif
diff --git a/mm/filemap.c b/mm/filemap.c
index 23edccecadb0..3461d97ecb30 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -446,7 +446,8 @@ int filemap_write_and_wait(struct address_space *mapping)
 {
         int err = 0;
 
-        if (mapping->nrpages) {
+        if ((!dax_mapping(mapping) && mapping->nrpages) ||
+            (dax_mapping(mapping) && mapping->nrexceptional)) {
                 err = filemap_fdatawrite(mapping);
                 /*
                  * Even if the above returned error, the pages may be
@@ -482,13 +483,8 @@ int filemap_write_and_wait_range(struct address_space *mapping,
 {
         int err = 0;
 
-        if (dax_mapping(mapping) && mapping->nrexceptional) {
-                err = dax_writeback_mapping_range(mapping, lstart, lend);
-                if (err)
-                        return err;
-        }
-
-        if (mapping->nrpages) {
+        if ((!dax_mapping(mapping) && mapping->nrpages) ||
+            (dax_mapping(mapping) && mapping->nrexceptional)) {
                 err = __filemap_fdatawrite_range(mapping, lstart, lend,
                                                  WB_SYNC_ALL);
                 /* See comment of filemap_write_and_wait() */