From 8c16d840377c1e6fb79f479ee60590a2da5b52ee Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Fri, 20 Oct 2006 11:48:33 +0200
Subject: [PATCH] [PATCH] Sanity check ops on loaded io engine

We require certain handlers to be there, or fio will either
malfunction or crash.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
 fio.c       |  8 --------
 fio.h       |  1 +
 ioengines.c | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/fio.c b/fio.c
index 818394a0..5673d9ef 100644
--- a/fio.c
+++ b/fio.c
@@ -424,14 +424,6 @@ static void do_io(struct thread_data *td)
 	}
 }
 
-static int td_io_init(struct thread_data *td)
-{
-	if (td->io_ops->init)
-		return td->io_ops->init(td);
-
-	return 0;
-}
-
 static void cleanup_io_u(struct thread_data *td)
 {
 	struct list_head *entry, *n;
diff --git a/fio.h b/fio.h
index 03a2378d..3817fc9a 100644
--- a/fio.h
+++ b/fio.h
@@ -497,6 +497,7 @@ extern void io_completed(struct thread_data *, struct io_u *, struct io_completi
 /*
  * io engine entry points
  */
+extern int td_io_init(struct thread_data *);
 extern int td_io_prep(struct thread_data *, struct io_u *);
 extern int td_io_queue(struct thread_data *, struct io_u *);
 extern int td_io_sync(struct thread_data *, struct fio_file *);
diff --git a/ioengines.c b/ioengines.c
index 5a321653..9b1ad606 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -14,9 +14,34 @@
 #include <unistd.h>
 #include <string.h>
 #include <dlfcn.h>
+
 #include "fio.h"
 #include "os.h"
 
+static int check_engine_ops(struct ioengine_ops *ops)
+{
+	/*
+	 * cpu thread doesn't need to provide anything
+	 */
+	if (ops->flags & FIO_CPUIO)
+		return 0;
+
+	if (!ops->event) {
+		log_err("%s: no event handler)\n", ops->name);
+		return 1;
+	}
+	if (!ops->getevents) {
+		log_err("%s: no getevents handler)\n", ops->name);
+		return 1;
+	}
+	if (!ops->queue) {
+		log_err("%s: no queue handler)\n", ops->name);
+		return 1;
+	}
+		
+	return 0;
+}
+
 struct ioengine_ops *load_ioengine(struct thread_data *td, char *name)
 {
 	char engine[16], engine_lib[256];
@@ -52,6 +77,14 @@ struct ioengine_ops *load_ioengine(struct thread_data *td, char *name)
 		return NULL;
 	}
 
+	/*
+	 * Check that the required methods are there.
+	 */
+	if (check_engine_ops(ops)) {
+		dlclose(dlhandle);
+		return NULL;
+	}
+
 	ret = malloc(sizeof(*ret));
 	memcpy(ret, ops, sizeof(*ret));
 	ret->data = NULL;
@@ -98,3 +131,11 @@ int td_io_queue(struct thread_data *td, struct io_u *io_u)
 
 	return td->io_ops->queue(td, io_u);
 }
+
+int td_io_init(struct thread_data *td)
+{
+	if (td->io_ops->init)
+		return td->io_ops->init(td);
+
+	return 0;
+}
-- 
2.25.1