diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index f55df0e..6d376ef 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -52,6 +52,23 @@ static int ext3_release_file (struct inode * inode, struct file * filp)
 	return 0;
 }
 
+static const struct vm_operations_struct ext3_file_vm_ops = {
+	.fault          = filemap_fault,
+	.page_mkwrite   = ext3_page_mkwrite,
+};
+
+static int ext3_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 = &ext3_file_vm_ops;
+	vma->vm_flags |= VM_CAN_NONLINEAR;
+	return 0;
+}
+
 const struct file_operations ext3_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
@@ -62,7 +79,7 @@ const struct file_operations ext3_file_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
 #endif
-	.mmap		= generic_file_mmap,
+	.mmap		= ext3_file_mmap,
 	.open		= dquot_file_open,
 	.release	= ext3_release_file,
 	.fsync		= ext3_sync_file,
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 68b2e43..66c31dd 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -3496,3 +3496,74 @@ int ext3_change_inode_journal_flag(struct inode *inode, int val)
 
 	return err;
 }
+
+int ext3_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	loff_t size;
+	unsigned long len;
+	int ret = -EINVAL;
+	void *fsdata;
+	struct file *file = vma->vm_file;
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct address_space *mapping = inode->i_mapping;
+
+	/*
+	 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
+	 * get i_mutex because we are already holding mmap_sem.
+	 */
+	down_read(&inode->i_alloc_sem);
+	size = i_size_read(inode);
+	if (page->mapping != mapping || size <= page_offset(page)
+	   || !PageUptodate(page)) {
+		/* page got truncated from under us? */
+		goto out_unlock;
+	}
+	ret = 0;
+	if (PageMappedToDisk(page))
+		goto out_frozen;
+
+	if (page->index == size >> PAGE_CACHE_SHIFT)
+		len = size & ~PAGE_CACHE_MASK;
+	else
+		len = PAGE_CACHE_SIZE;
+
+	lock_page(page);
+	/*
+	 * return if we have all the buffers mapped. This avoid
+	 * the need to call write_begin/write_end which does a
+	 * journal_start/journal_stop which can block and take
+	 * long time
+	 */
+	if (page_has_buffers(page)) {
+		if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+					buffer_unmapped)) {
+			unlock_page(page);
+out_frozen:
+			vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+			goto out_unlock;
+		}
+	}
+	unlock_page(page);
+	/*
+	 * OK, we need to fill the hole... Do write_begin write_end
+	 * to do block allocation/reservation.We are not holding
+	 * inode.i__mutex here. That allow * parallel write_begin,
+	 * write_end call. lock_page prevent this from happening
+	 * on the same page though
+	 */
+	ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
+			len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
+	if (ret < 0)
+		goto out_unlock;
+	ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
+			len, len, page, fsdata);
+	if (ret < 0)
+		goto out_unlock;
+	ret = 0;
+out_unlock:
+	if (ret)
+		ret = VM_FAULT_SIGBUS;
+	up_read(&inode->i_alloc_sem);
+	return ret;
+}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f2fa5e8..44979ae 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5812,7 +5812,7 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	}
 	ret = 0;
 	if (PageMappedToDisk(page))
-		goto out_unlock;
+		goto out_frozen;
 
 	if (page->index == size >> PAGE_CACHE_SHIFT)
 		len = size & ~PAGE_CACHE_MASK;
@@ -5830,6 +5830,8 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 		if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
 					ext4_bh_unmapped)) {
 			unlock_page(page);
+out_frozen:
+			vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 			goto out_unlock;
 		}
 	}
diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 85c1d30..a0e39ca 100644
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -919,6 +919,7 @@ extern void ext3_get_inode_flags(struct ext3_inode_info *);
 extern void ext3_set_aops(struct inode *inode);
 extern int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		       u64 start, u64 len);
+extern int ext3_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
 
 /* ioctl.c */
 extern long ext3_ioctl(struct file *, unsigned int, unsigned long);
