Hello everyone, I'm currently writing a block device driver and got stuck at trying to understand how to correctly handle the locking in the reqfn one passes to `blk_init_queue`. My code looks like this: static DEFINE_SPINLOCK(rblk_lock); /* Code */ static void rblk_request_handler(struct request_queue *q) __releases(q->queue_lock) __acquires(q->queue_lock) { struct request* req; unsigned long flags = 0; printk(KERN_INFO "rblk: Got request(s) \n"); while ((req = blk_fetch_request(q)) != NULL) { printk(KERN_INFO "rblk: Handling request \n"); // <- Gets printed spin_lock_irqsave(q->queue_lock, flags); blk_end_request_all(req, -ENOTTY); spin_unlock_irqrestore(q->queue_lock, flags); printk(KERN_INFO "rblk: Handled request \n"); // <- Does not get printed } } static in rblk_init() { /* Get major number, allocate devices */ for (i = 0; i < rblk_cnt; i++) { // For each device /* alloc_disk, check for allocation fail */ disk->queue = blk_init_queue(rblk_request_handler, &rblk_lock); } } This didn't work, and it was obvious to me that it was hanging in the spinlock. So I tried removing the locking, (this SO answer says that the queue is already locked: https://stackoverflow.com/questions/19418979/proper-way-to-lock-the-queue-in...) however, I still get the problem that the queue locks up and the second message never hits the message queue. What /does/ work is if I invert the order of locking. As in, unlock first, end_request and then lock again. However that doesn't seem to be the correct way. What am I doing completely wrong, what did I misunderstand? Full code: https://gist.github.com/TheNeikos/8798788defa1a9f316e6 Thanks