Add define for CONFIG_AIO_OPTIMIZATION that we use in many kernels.

It's needs the 3.16.y functions defines.

exfat_super.c

@@ -1577,9 +1577,14 @@ static int exfat_write_end(struct file *file, struct address_space *mapping,
 }
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0)
+#ifdef CONFIG_AIO_OPTIMIZATION
+static ssize_t exfat_direct_IO(int rw, struct kiocb *iocb,
+						struct iov_iter *iter, loff_t offset)
+#else
 static ssize_t exfat_direct_IO(int rw, struct kiocb *iocb,
 					   const struct iovec *iov,
 					   loff_t offset, unsigned long nr_segs)
+#endif
 #else
 static ssize_t exfat_direct_IO(int rw, struct kiocb *iocb,
 					   struct iov_iter *iter, loff_t offset)
@@ -1593,7 +1598,12 @@ static ssize_t exfat_direct_IO(int rw, struct kiocb *iocb,
 
 	if (rw == WRITE) {
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0)
+#ifdef CONFIG_AIO_OPTIMIZATION
+		if (EXFAT_I(inode)->mmu_private <
+					(offset + iov_iter_count(iter)))
+#else
 		if (EXFAT_I(inode)->mmu_private < (offset + iov_length(iov, nr_segs)))
+#endif
 #else
 		if (EXFAT_I(inode)->mmu_private < (offset + iov_iter_count(iter)))
 #endif
@@ -1603,8 +1613,13 @@ static ssize_t exfat_direct_IO(int rw, struct kiocb *iocb,
 	ret = blockdev_direct_IO(rw, iocb, inode, iter,
 					offset, exfat_get_block);
 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0)
+#ifdef CONFIG_AIO_OPTIMIZATION
+	ret = blockdev_direct_IO(rw, iocb, inode, iter,
+					offset, exfat_get_block);
+#else
 	ret = blockdev_direct_IO(rw, iocb, inode, iov,
 					offset, nr_segs, exfat_get_block);
+#endif
 #else
         ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
 					offset, nr_segs, exfat_get_block, NULL);
@@ -1615,7 +1630,11 @@ static ssize_t exfat_direct_IO(int rw, struct kiocb *iocb,
 		exfat_write_failed(mapping, offset+iov_iter_count(iter));
 #elif LINUX_VERSION_CODE > KERNEL_VERSION(2,6,34)
 	if ((ret < 0) && (rw & WRITE))
+#ifdef CONFIG_AIO_OPTIMIZATION
+		exfat_write_failed(mapping, offset+iov_iter_count(iter));
+#else
 		exfat_write_failed(mapping, offset+iov_length(iov, nr_segs));
+#endif
 #endif
 	return ret;
 }
@@ -1867,7 +1886,7 @@ static void exfat_evict_inode(struct inode *inode)
 	if (!inode->i_nlink)
 		i_size_write(inode, 0);
 	invalidate_inode_buffers(inode);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,5,0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,4,80)
 	end_writeback(inode);
 #else
 	clear_inode(inode);