X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=ioengines.c;h=fa4acab2b3fa349a57993d086048a4709cb9b68a;hb=aa6cb4598cfde5a1c3f58e39160a2b2b99369625;hp=0c631e85e98806921568900f564295fa1e6e4a6e;hpb=81647a9a229b92635062e0a1ee570997634b7848;p=fio.git

diff --git a/ioengines.c b/ioengines.c
index 0c631e85..fa4acab2 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -123,32 +123,50 @@ static struct ioengine_ops *dlopen_ioengine(struct thread_data *td,
 	return ops;
 }
 
-struct ioengine_ops *load_ioengine(struct thread_data *td)
+static struct ioengine_ops *__load_ioengine(const char *name)
 {
-	struct ioengine_ops *ops = NULL;
-	const char *name = NULL;
+	char engine[64];
 
-	if (strcmp(td->o.ioengine, "external")) {
-		char engine[64];
+	engine[sizeof(engine) - 1] = '\0';
+	strncpy(engine, name, sizeof(engine) - 1);
 
-		name = td->o.ioengine;
-		engine[sizeof(engine) - 1] = '\0';
-		strncpy(engine, name, sizeof(engine) - 1);
+	/*
+	 * linux libaio has alias names, so convert to what we want
+	 */
+	if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3))
+		strcpy(engine, "libaio");
 
-		/*
-		 * linux libaio has alias names, so convert to what we want
-		 */
-		if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3))
-			strcpy(engine, "libaio");
+	dprint(FD_IO, "load ioengine %s\n", engine);
+	return find_ioengine(engine);
+}
+
+struct ioengine_ops *load_ioengine(struct thread_data *td)
+{
+	struct ioengine_ops *ops = NULL;
+	const char *name;
 
-		dprint(FD_IO, "load ioengine %s\n", engine);
-		ops = find_ioengine(engine);
-	} else if (td->o.ioengine_so_path) {
-		name = td->o.ioengine_so_path;
+	/*
+	 * Use ->ioengine_so_path if an external ioengine path is specified.
+	 * In this case, ->ioengine is "external" which also means the prefix
+	 * for external ioengines "external:" is properly used.
+	 */
+	name = td->o.ioengine_so_path ?: td->o.ioengine;
+
+	/*
+	 * Try to load ->ioengine first, and if failed try to dlopen(3) either
+	 * ->ioengine or ->ioengine_so_path.  This is redundant for an external
+	 * ioengine with prefix, and also leaves the possibility of unexpected
+	 * behavior (e.g. if the "external" ioengine exists), but we do this
+	 * so as not to break job files not using the prefix.
+	 */
+	ops = __load_ioengine(td->o.ioengine);
+	if (!ops)
 		ops = dlopen_ioengine(td, name);
-	} else
-		log_err("fio: missing external ioengine path\n");
 
+	/*
+	 * If ops is NULL, we failed to load ->ioengine, and also failed to
+	 * dlopen(3) either ->ioengine or ->ioengine_so_path as a path.
+	 */
 	if (!ops) {
 		log_err("fio: engine %s not loadable\n", name);
 		return NULL;
@@ -558,7 +576,6 @@ int td_io_get_file_size(struct thread_data *td, struct fio_file *f)
 int fio_show_ioengine_help(const char *engine)
 {
 	struct flist_head *entry;
-	struct thread_data td;
 	struct ioengine_ops *io_ops;
 	char *sep;
 	int ret = 1;
@@ -577,10 +594,7 @@ int fio_show_ioengine_help(const char *engine)
 		sep++;
 	}
 
-	memset(&td, 0, sizeof(td));
-
-	td.o.ioengine = (char *)engine;
-	io_ops = load_ioengine(&td);
+	io_ops = __load_ioengine(engine);
 	if (!io_ops) {
 		log_info("IO engine %s not found\n", engine);
 		return 1;
@@ -591,7 +605,5 @@ int fio_show_ioengine_help(const char *engine)
 	else
 		log_info("IO engine %s has no options\n", io_ops->name);
 
-	free_ioengine(&td);
-
 	return ret;
 }