From 133ff979b5dac5988ca31b2dd1373be95ab362a4 Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@1und1.de>
Date: Fri, 5 Feb 2021 08:01:01 +0100
Subject: [PATCH] bio: allow throttling for testing

---
 kernel/mars_bio.c         | 17 +++++++++++++++++
 kernel/mars_bio.h         |  2 ++
 kernel/sy_old/mars_proc.c |  2 ++
 3 files changed, 21 insertions(+)

diff --git a/kernel/mars_bio.c b/kernel/mars_bio.c
index c180d4d9..1b36a556 100644
--- a/kernel/mars_bio.c
+++ b/kernel/mars_bio.c
@@ -39,6 +39,7 @@
 #include "mars.h"
 #include "lib_timing.h"
 #include "lib_mapfree.h"
+#include "lib_limiter.h"
 
 #include "mars_bio.h"
 
@@ -73,6 +74,13 @@ struct threshold bio_io_threshold[2] = {
 };
 EXPORT_SYMBOL_GPL(bio_io_threshold);
 
+#ifdef CONFIG_MARS_DEBUG
+struct mars_limiter bio_throttle_read = {
+};
+struct mars_limiter bio_throttle_write = {
+};
+#endif
+
 ///////////////////////// own type definitions ////////////////////////
 
 ///////////////////////// own helper functions ////////////////////////
@@ -344,6 +352,15 @@ static int bio_ref_get(struct bio_output *output, struct mref_object *mref)
 		mref_a->do_dealloc = true;
 	}
 
+#ifdef CONFIG_MARS_DEBUG
+	/* Only for testing, e.g. simulation of degraded RAID etc
+	 */
+	if (mref->ref_flags & MREF_WRITE)
+		mars_limit_sleep(&bio_throttle_write, (mref->ref_len + 512) / 1024);
+	else
+		mars_limit_sleep(&bio_throttle_read, (mref->ref_len + 512) / 1024);
+#endif
+
 	status = make_bio(output->brick, mref->ref_data, mref->ref_len, mref->ref_pos, mref_a, &mref_a->bio);
 	if (unlikely(status < 0 || !mref_a->bio)) {
 		MARS_ERR("could not create bio, status = %d\n", status);
diff --git a/kernel/mars_bio.h b/kernel/mars_bio.h
index aca48f09..28ab19b0 100644
--- a/kernel/mars_bio.h
+++ b/kernel/mars_bio.h
@@ -32,6 +32,8 @@
 
 #ifdef CONFIG_MARS_DEBUG
 #define MARS_BIO_DEBUG
+extern struct mars_limiter bio_throttle_read;
+extern struct mars_limiter bio_throttle_write;
 #endif
 
 extern int bio_nr_requests;
diff --git a/kernel/sy_old/mars_proc.c b/kernel/sy_old/mars_proc.c
index 04813e18..54c97099 100644
--- a/kernel/sy_old/mars_proc.c
+++ b/kernel/sy_old/mars_proc.c
@@ -444,6 +444,8 @@ struct ctl_table mars_table[] = {
 #ifdef CONFIG_MARS_DEBUG
 	INT_ENTRY("debug_crash_mode",     mars_crash_mode,        0600),
 	INT_ENTRY("debug_hang_mode",      mars_hang_mode,         0600),
+	LIMITER_ENTRIES(&bio_throttle_read,  "debug_bio_throttle_read",  "kb"),
+	LIMITER_ENTRIES(&bio_throttle_write, "debug_bio_throttle_write", "kb"),
 #endif
 	INT_ENTRY("logger_completion_semantics", trans_logger_completion_semantics, 0600),
 	INT_ENTRY("logger_do_crc",        trans_logger_do_crc,    0600),