1 files changed, 18 insertions, 1 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 4159be6366ab..b9510ba66a2d 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -123,6 +123,23 @@ force_commit:
         return ret;
 }
 
+static struct vm_operations_struct ext4_file_vm_ops = {
+        .fault          = filemap_fault,
+        .page_mkwrite   = ext4_page_mkwrite,
+};
+
+static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+        struct address_space *mapping = file->f_mapping;
+
+        if (!mapping->a_ops->readpage)
+                return -ENOEXEC;
+        file_accessed(file);
+        vma->vm_ops = &ext4_file_vm_ops;
+        vma->vm_flags |= VM_CAN_NONLINEAR;
+        return 0;
+}
+
 const struct file_operations ext4_file_operations = {
         .llseek         = generic_file_llseek,
         .read           = do_sync_read,
@@ -133,7 +150,7 @@ const struct file_operations ext4_file_operations = {
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = ext4_compat_ioctl,
 #endif
-        .mmap           = generic_file_mmap,
+        .mmap           = ext4_file_mmap,
         .open           = generic_file_open,
         .release        = ext4_release_file,
         .fsync          = ext4_sync_file,