[PATCH 08/17] tools: blktap2: don't return negative event id

[Wen Congyang <wency@cn.fujitsu.com>]

If we find some error when registering a new event, we will return
a negative value. So we should skip negative event id.

Also fix a wrong check of return value.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Shriram Rajagopalan <rshriram@cs.ubc.ca>
---
 tools/blktap2/drivers/scheduler.c       | 8 ++++----
 tools/blktap2/drivers/tapdisk-control.c | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/blktap2/drivers/scheduler.c b/tools/blktap2/drivers/scheduler.c
index dd608dd..e07528b 100644
--- a/tools/blktap2/drivers/scheduler.c
+++ b/tools/blktap2/drivers/scheduler.c
@@ -167,15 +167,15 @@ get_free_id(scheduler_t *s)
 	int old_uuid = s->uuid;
 	int id = s->uuid++;
 
-	if (!s->uuid)
-		s->uuid++;
+	if (s->uuid < 0)
+		s->uuid = 1;
 
 retry:
 	scheduler_for_each_event(s, event, tmp)
 		if (event->id == id) {
 			id = s->uuid++;
-			if (!s->uuid)
-				s->uuid++;
+			if (s->uuid < 0)
+				s->uuid = 1;
 			if (id == old_uuid)
 				return 0;
 
diff --git a/tools/blktap2/drivers/tapdisk-control.c b/tools/blktap2/drivers/tapdisk-control.c
index 3a4ec8e..4e5f748 100644
--- a/tools/blktap2/drivers/tapdisk-control.c
+++ b/tools/blktap2/drivers/tapdisk-control.c
@@ -700,7 +700,7 @@ tapdisk_control_accept(event_id_t id, char mode, void *private)
 					    connection->socket, 0,
 					    tapdisk_control_handle_request,
 					    connection);
-	if (err == -1) {
+	if (err < 0) {
 		close(fd);
 		free(connection);
 		EPRINTF("failed to register new control event: %d\n", err);
-- 
1.9.3