From f654129e94fa10afa44a8c188a879d7079b9eeed Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@1und1.de>
Date: Fri, 26 Aug 2016 09:04:02 +0200
Subject: [PATCH] compat: disable aio when necessary

---
 kernel/mars.h              |  5 ++++-
 kernel/mars_aio.c          | 13 +++++++++++--
 kernel/mars_aio.h          |  1 +
 kernel/sy_old/sy_generic.c |  2 +-
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/kernel/mars.h b/kernel/mars.h
index 8a395c21..5cf0d31b 100644
--- a/kernel/mars.h
+++ b/kernel/mars.h
@@ -381,8 +381,11 @@ extern const struct generic_brick_type *_bio_brick_type;
 extern const struct generic_brick_type *_aio_brick_type;
 extern const struct generic_brick_type *_sio_brick_type;
 
-#ifndef CONFIG_MARS_PREFER_SIO
+#if !defined(CONFIG_MARS_PREFER_SIO) && defined(HAS_MARS_PREPATCH)
+#define ENABLE_MARS_AIO
+#endif
 
+#ifdef ENABLE_MARS_AIO
 /* Kludge: our kernel threads will have no mm context, but need one
  * for stuff like ioctx_alloc() / aio_setup_ring() etc
  * which expect userspace resources.
diff --git a/kernel/mars_aio.c b/kernel/mars_aio.c
index fcdeb732..85693f15 100644
--- a/kernel/mars_aio.c
+++ b/kernel/mars_aio.c
@@ -46,7 +46,7 @@
 #define MARS_MAX_AIO      512
 #define MARS_MAX_AIO_READ 32
 
-static struct timing_stats timings[3] = {};
+struct timing_stats timings[3] = {};
 
 struct threshold aio_submit_threshold = {
 	.thr_ban = &mars_global_ban,
@@ -90,6 +90,8 @@ EXPORT_SYMBOL_GPL(aio_sync_mode);
 
 ////////////////// some helpers //////////////////
 
+#ifdef ENABLE_MARS_AIO
+
 static inline
 void _enqueue(struct aio_threadinfo *tinfo, struct aio_mref_aspect *mref_a, int prio, bool at_end)
 {
@@ -1068,7 +1070,7 @@ void aio_reset_statistics(struct aio_brick *brick)
 	}
 }
 
-
+#endif /* ENABLE_MARS_AIO */
 //////////////// object / aspect constructors / destructors ///////////////
 
 static int aio_mref_aspect_init_fn(struct generic_aspect *_ini)
@@ -1089,6 +1091,7 @@ static void aio_mref_aspect_exit_fn(struct generic_aspect *_ini)
 
 MARS_MAKE_STATICS(aio);
 
+#ifdef ENABLE_MARS_AIO
 ////////////////////// brick constructors / destructors ////////////////////
 
 static int aio_brick_construct(struct aio_brick *brick)
@@ -1240,16 +1243,22 @@ static const struct aio_output_type *aio_output_types[] = {
 	&aio_output_type,
 };
 
+#endif /* ENABLE_MARS_AIO */
+
 const struct aio_brick_type aio_brick_type = {
 	.type_name = "aio_brick",
 	.brick_size = sizeof(struct aio_brick),
 	.max_inputs = 0,
 	.max_outputs = 1,
+#ifdef ENABLE_MARS_AIO
 	.master_ops = &aio_brick_ops,
 	.aspect_types = aio_aspect_types,
 	.default_input_types = aio_input_types,
 	.default_output_types = aio_output_types,
 	.brick_construct = &aio_brick_construct,
+#else /* ENABLE_MARS_AIO */
+	.aspect_types = aio_aspect_types,	/* dummy, shut up gcc */
+#endif /* ENABLE_MARS_AIO */
 };
 EXPORT_SYMBOL_GPL(aio_brick_type);
 
diff --git a/kernel/mars_aio.h b/kernel/mars_aio.h
index 29872282..fa467e12 100644
--- a/kernel/mars_aio.h
+++ b/kernel/mars_aio.h
@@ -27,6 +27,7 @@
 #include <linux/aio.h>
 #include <linux/syscalls.h>
 
+#include "mars.h"
 #include "lib_mapfree.h"
 
 #define AIO_SUBMIT_MAX_LATENCY    1000 //   1 ms
diff --git a/kernel/sy_old/sy_generic.c b/kernel/sy_old/sy_generic.c
index 99312c82..66bdeb27 100644
--- a/kernel/sy_old/sy_generic.c
+++ b/kernel/sy_old/sy_generic.c
@@ -1925,7 +1925,7 @@ struct mars_brick *make_brick_all(
 			MARS_DBG("substitute bio by aio\n");
 		}
 	}
-#ifdef CONFIG_MARS_PREFER_SIO
+#ifndef ENABLE_MARS_AIO
 	if (!brick && new_brick_type == _aio_brick_type && _sio_brick_type) {
 		new_brick_type = _sio_brick_type;
 		MARS_DBG("substitute aio by sio\n");