1 files changed, 47 insertions, 2 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 7cb592386121..33a09da16c9c 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -95,7 +95,7 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
         struct inode *inode = file_inode(iocb->ki_filp);
         struct mutex *aio_mutex = NULL;
         struct blk_plug plug;
-        int o_direct = file->f_flags & O_DIRECT;
+        int o_direct = io_is_direct(file);
         int overwrite = 0;
         size_t length = iov_iter_count(from);
         ssize_t ret;
@@ -191,6 +191,26 @@ errout:
         return ret;
 }
 
+#ifdef CONFIG_FS_DAX
+static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        return dax_fault(vma, vmf, ext4_get_block);
+                                        /* Is this the right get_block? */
+}
+
+static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        return dax_mkwrite(vma, vmf, ext4_get_block);
+}
+
+static const struct vm_operations_struct ext4_dax_vm_ops = {
+        .fault          = ext4_dax_fault,
+        .page_mkwrite   = ext4_dax_mkwrite,
+};
+#else
+#define ext4_dax_vm_ops ext4_file_vm_ops
+#endif
+
 static const struct vm_operations_struct ext4_file_vm_ops = {
         .fault          = filemap_fault,
         .map_pages      = filemap_map_pages,
@@ -200,7 +220,12 @@ static const struct vm_operations_struct ext4_file_vm_ops = {
 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
         file_accessed(file);
-        vma->vm_ops = &ext4_file_vm_ops;
+        if (IS_DAX(file_inode(file))) {
+                vma->vm_ops = &ext4_dax_vm_ops;
+                vma->vm_flags |= VM_MIXEDMAP;
+        } else {
+                vma->vm_ops = &ext4_file_vm_ops;
+        }
         return 0;
 }
 
@@ -599,6 +624,26 @@ const struct file_operations ext4_file_operations = {
         .fallocate      = ext4_fallocate,
 };
 
+#ifdef CONFIG_FS_DAX
+const struct file_operations ext4_dax_file_operations = {
+        .llseek         = ext4_llseek,
+        .read           = new_sync_read,
+        .write          = new_sync_write,
+        .read_iter      = generic_file_read_iter,
+        .write_iter     = ext4_file_write_iter,
+        .unlocked_ioctl = ext4_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl   = ext4_compat_ioctl,
+#endif
+        .mmap           = ext4_file_mmap,
+        .open           = ext4_file_open,
+        .release        = ext4_release_file,
+        .fsync          = ext4_sync_file,
+        /* Splice not yet supported with DAX */
+        .fallocate      = ext4_fallocate,
+};
+#endif
+
 const struct inode_operations ext4_file_inode_operations = {
         .setattr        = ext4_setattr,
         .getattr        = ext4_getattr,