[PATCH 2/4] ioengine: allow several external ioengines

[Dmitry Monakhov <dmonakhov@openvz.org>]

Currently only one external ioengine can be exported because
it use hardcoded 'ioengine' symbol, but if we allow external
modules to have ops symbol similar to it's name then several
extrnal engines become possible.

NOTE: Old linking layout preserved

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
 ioengines.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/ioengines.c b/ioengines.c
index b43374e..c2a64cb 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -104,7 +104,9 @@ static struct ioengine_ops *dlopen_ioengine(struct thread_data *td,
 	 * Unlike the included modules, external engines should have a
 	 * non-static ioengine structure that we can reference.
 	 */
-	ops = dlsym(dlhandle, "ioengine");
+	ops = dlsym(dlhandle, engine_lib);
+	if (!ops)
+		ops = dlsym(dlhandle, "ioengine");
 	if (!ops) {
 		td_vmsg(td, -1, dlerror(), "dlsym");
 		dlclose(dlhandle);
-- 
1.7.7.6