ALSA: seq: 2nd attempt at fixing race creating a queue

[karo-tx-linux.git] / sound / core / seq / seq_queue.c

diff --git a/sound/core/seq/seq_queue.c b/sound/core/seq/seq_queue.c
index 450c5187eecb6bb083736d2d2a1aad43b98c7c3f..79e0c5604ef806d62eca084293e66222b8fe6828 100644 (file)
--- a/sound/core/seq/seq_queue.c
+++ b/sound/core/seq/seq_queue.c
@@ -184,22 +184,26 @@ void __exit snd_seq_queues_delete(void)
 static void queue_use(struct snd_seq_queue *queue, int client, int use);
 
 /* allocate a new queue -
- * return queue index value or negative value for error
+ * return pointer to new queue or ERR_PTR(-errno) for error
+ * The new queue's use_lock is set to 1. It is the caller's responsibility to
+ * call snd_use_lock_free(&q->use_lock).
  */
-int snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
+struct snd_seq_queue *snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
 {
        struct snd_seq_queue *q;
 
        q = queue_new(client, locked);
        if (q == NULL)
-               return -ENOMEM;
+               return ERR_PTR(-ENOMEM);
        q->info_flags = info_flags;
        queue_use(q, client, 1);
+       snd_use_lock_use(&q->use_lock);
        if (queue_list_add(q) < 0) {
+               snd_use_lock_free(&q->use_lock);
                queue_delete(q);
-               return -ENOMEM;
+               return ERR_PTR(-ENOMEM);
        }
-       return q->queue;
+       return q;
 }
 
 /* delete a queue - queue must be owned by the client */