[PATCH 1/2] engines/xnvme: fix segfault issue with xnvme ioengine

[Ankit Kumar <ankit.kumar@xxxxxxxxxxx>]

fix segfault when xnvme ioengine is called without thread=1.
The segfault happens because td->io_ops_data is accessed at
two locations xnvme_fioe_cleanup and xnvme_fioe_iomem_free,
during the error handling call.

Signed-off-by: Ankit Kumar <ankit.kumar@xxxxxxxxxxx>
---
 engines/xnvme.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/engines/xnvme.c b/engines/xnvme.c
index c11b33a8..d8647481 100644
--- a/engines/xnvme.c
+++ b/engines/xnvme.c
@@ -205,9 +205,14 @@ static void _dev_close(struct thread_data *td, struct xnvme_fioe_fwrap *fwrap)
 
 static void xnvme_fioe_cleanup(struct thread_data *td)
 {
-	struct xnvme_fioe_data *xd = td->io_ops_data;
+	struct xnvme_fioe_data *xd = NULL;
 	int err;
 
+	if (!td->io_ops_data)
+		return;
+
+	xd = td->io_ops_data;
+
 	err = pthread_mutex_lock(&g_serialize);
 	if (err)
 		log_err("ioeng->cleanup(): pthread_mutex_lock(), err(%d)\n", err);
@@ -367,8 +372,14 @@ static int xnvme_fioe_iomem_alloc(struct thread_data *td, size_t total_mem)
 /* NOTE: using the first device for buffer-allocators) */
 static void xnvme_fioe_iomem_free(struct thread_data *td)
 {
-	struct xnvme_fioe_data *xd = td->io_ops_data;
-	struct xnvme_fioe_fwrap *fwrap = &xd->files[0];
+	struct xnvme_fioe_data *xd = NULL;
+	struct xnvme_fioe_fwrap *fwrap = NULL;
+
+	if (!td->io_ops_data)
+		return;
+
+	xd = td->io_ops_data;
+	fwrap = &xd->files[0];
 
 	if (!fwrap->dev) {
 		log_err("ioeng->iomem_free(): failed no dev-handle\n");
-- 
2.17.1