From a467027e1c8ae59053bf24eafdceb22f09391028 Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Fri, 7 Apr 2017 07:59:01 +0300
Subject: [PATCH] engine: add ftruncate ioengine

Currently fio does many things but it still cannot substitute fsx
because it does not support ftruncate. Let's add this.
---
 Makefile            |  1 +
 engines/ftruncate.c | 56 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 engines/ftruncate.c

diff --git a/Makefile b/Makefile
index 37150c69..66083ffc 100644
--- a/Makefile
+++ b/Makefile
@@ -42,6 +42,7 @@ SOURCE :=	$(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/crc/*.c)) \
 		eta.c verify.c memory.c io_u.c parse.c mutex.c options.c \
 		smalloc.c filehash.c profile.c debug.c engines/cpu.c \
 		engines/mmap.c engines/sync.c engines/null.c engines/net.c \
+		engines/ftruncate.c \
 		server.c client.c iolog.c backend.c libfio.c flow.c cconv.c \
 		gettime-thread.c helpers.c json.c idletime.c td_error.c \
 		profiles/tiobench.c profiles/act.c io_u_queue.c filelock.c \
diff --git a/engines/ftruncate.c b/engines/ftruncate.c
new file mode 100644
index 00000000..e86dbac0
--- /dev/null
+++ b/engines/ftruncate.c
@@ -0,0 +1,56 @@
+/*
+ * ftruncate: ioengine for git://git.kernel.dk/fio.git
+ *
+ * IO engine that does regular truncates to simulate data transfer
+ * as fio ioengine.
+ * DDIR_WRITE does ftruncate
+ *
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/uio.h>
+#include <errno.h>
+#include <assert.h>
+#include <fcntl.h>
+
+#include "../fio.h"
+#include "../filehash.h"
+
+static int fio_ftruncate_queue(struct thread_data *td, struct io_u *io_u)
+{
+	struct fio_file *f = io_u->file;
+	int ret;
+	fio_ro_check(td, io_u);
+
+	if (io_u->ddir != DDIR_WRITE) {
+		io_u->error = EINVAL;
+		return FIO_Q_COMPLETED;
+	}
+	ret = ftruncate(f->fd, io_u->offset);
+
+	if (ret)
+		io_u->error = errno;
+
+	return FIO_Q_COMPLETED;
+}
+
+static struct ioengine_ops ioengine = {
+	.name		= "ftruncate",
+	.version	= FIO_IOOPS_VERSION,
+	.queue		= fio_ftruncate_queue,
+	.open_file	= generic_open_file,
+	.close_file	= generic_close_file,
+	.get_file_size	= generic_get_file_size,
+	.flags		= FIO_SYNCIO | FIO_FAKEIO
+};
+
+static void fio_init fio_syncio_register(void)
+{
+	register_ioengine(&ioengine);
+}
+
+static void fio_exit fio_syncio_unregister(void)
+{
+	unregister_ioengine(&ioengine);
+}
-- 
2.25.1