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Commit ff482f7f authored by Jens Axboe's avatar Jens Axboe
Browse files

Merge tag 'nbd-for-4.6' of git://git.pengutronix.de/git/mpa/linux-nbd into for-4.6/drivers 

NBD for 4.6

Markus writes:

This pull request contains 7 patches for 4.6.

Patch 1 fixes some unnecessarily complicated code I introduced some versions
ago for debugfs.

Patch 2 removes the criticised signal usage within NBD to kill the NBD threads
after a timeout. This code was used for the last years and is now replaced by
simply killing the tcp connection.

Patches 3-6 are some smaller cleanups.

Patch 7 uevents for the userspace. This way udev/systemd can react on connected
NBD devices.
parents 931e1c22 37091fdd

drivers/block/nbd.c

+170 −165
Original line number Diff line number Diff line
@@ -57,10 +57,12 @@ struct nbd_device { 
	int blksize;

	loff_t bytesize;

	int xmit_timeout;

	bool timedout;

	bool disconnect; /* a disconnect has been requested by user */



	struct timer_list timeout_timer;

	spinlock_t tasks_lock;

	/* protects initialization and shutdown of the socket */

	spinlock_t sock_lock;

	struct task_struct *task_recv;

	struct task_struct *task_send;
@@ -98,6 +100,11 @@ static inline struct device *nbd_to_dev(struct nbd_device *nbd) 
	return disk_to_dev(nbd->disk);

}



static bool nbd_is_connected(struct nbd_device *nbd)

{

	return !!nbd->task_recv;

}



static const char *nbdcmd_to_ascii(int cmd)

{

	switch (cmd) {
@@ -110,6 +117,42 @@ static const char *nbdcmd_to_ascii(int cmd) 
	return "invalid";

}



static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev)

{

	bdev->bd_inode->i_size = 0;

	set_capacity(nbd->disk, 0);

	kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);



	return 0;

}



static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev)

{

	if (!nbd_is_connected(nbd))

		return;



	bdev->bd_inode->i_size = nbd->bytesize;

	set_capacity(nbd->disk, nbd->bytesize >> 9);

	kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);

}



static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev,

			int blocksize, int nr_blocks)

{

	int ret;



	ret = set_blocksize(bdev, blocksize);

	if (ret)

		return ret;



	nbd->blksize = blocksize;

	nbd->bytesize = (loff_t)blocksize * (loff_t)nr_blocks;



	nbd_size_update(nbd, bdev);



	return 0;

}



static void nbd_end_request(struct nbd_device *nbd, struct request *req)

{

	int error = req->errors ? -EIO : 0;
@@ -129,13 +172,20 @@ static void nbd_end_request(struct nbd_device *nbd, struct request *req) 
 */

static void sock_shutdown(struct nbd_device *nbd)

{

	if (!nbd->sock)

	spin_lock_irq(&nbd->sock_lock);



	if (!nbd->sock) {

		spin_unlock_irq(&nbd->sock_lock);

		return;

	}



	dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n");

	kernel_sock_shutdown(nbd->sock, SHUT_RDWR);

	sockfd_put(nbd->sock);

	nbd->sock = NULL;

	del_timer_sync(&nbd->timeout_timer);

	spin_unlock_irq(&nbd->sock_lock);



	del_timer(&nbd->timeout_timer);

}



static void nbd_xmit_timeout(unsigned long arg)
@@ -146,19 +196,16 @@ static void nbd_xmit_timeout(unsigned long arg) 
	if (list_empty(&nbd->queue_head))

		return;



	nbd->disconnect = true;

	spin_lock_irqsave(&nbd->sock_lock, flags);



	spin_lock_irqsave(&nbd->tasks_lock, flags);



	if (nbd->task_recv)

		force_sig(SIGKILL, nbd->task_recv);

	nbd->timedout = true;



	if (nbd->task_send)

		force_sig(SIGKILL, nbd->task_send);

	if (nbd->sock)

		kernel_sock_shutdown(nbd->sock, SHUT_RDWR);



	spin_unlock_irqrestore(&nbd->tasks_lock, flags);

	spin_unlock_irqrestore(&nbd->sock_lock, flags);



	dev_err(nbd_to_dev(nbd), "Connection timed out, killed receiver and sender, shutting down connection\n");

	dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n");

}



/*
@@ -171,7 +218,6 @@ static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, 
	int result;

	struct msghdr msg;

	struct kvec iov;

	sigset_t blocked, oldset;

	unsigned long pflags = current->flags;



	if (unlikely(!sock)) {
@@ -181,11 +227,6 @@ static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, 
		return -EINVAL;

	}



	/* Allow interception of SIGKILL only

	 * Don't allow other signals to interrupt the transmission */

	siginitsetinv(&blocked, sigmask(SIGKILL));

	sigprocmask(SIG_SETMASK, &blocked, &oldset);



	current->flags |= PF_MEMALLOC;

	do {

		sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
@@ -212,7 +253,6 @@ static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, 
		buf += result;

	} while (size > 0);



	sigprocmask(SIG_SETMASK, &oldset, NULL);

	tsk_restore_flags(current, pflags, PF_MEMALLOC);



	if (!send && nbd->xmit_timeout)
@@ -402,31 +442,28 @@ static struct device_attribute pid_attr = { 
	.show = pid_show,

};



static int nbd_thread_recv(struct nbd_device *nbd)

static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev)

{

	struct request *req;

	int ret;

	unsigned long flags;



	BUG_ON(nbd->magic != NBD_MAGIC);



	sk_set_memalloc(nbd->sock->sk);



	spin_lock_irqsave(&nbd->tasks_lock, flags);

	nbd->task_recv = current;

	spin_unlock_irqrestore(&nbd->tasks_lock, flags);



	ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr);

	if (ret) {

		dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");



		spin_lock_irqsave(&nbd->tasks_lock, flags);

		nbd->task_recv = NULL;

		spin_unlock_irqrestore(&nbd->tasks_lock, flags);



		return ret;

	}



	nbd_size_update(nbd, bdev);



	while (1) {

		req = nbd_read_stat(nbd);

		if (IS_ERR(req)) {
@@ -437,21 +474,11 @@ static int nbd_thread_recv(struct nbd_device *nbd) 
		nbd_end_request(nbd, req);

	}



	nbd_size_clear(nbd, bdev);



	device_remove_file(disk_to_dev(nbd->disk), &pid_attr);



	spin_lock_irqsave(&nbd->tasks_lock, flags);

	nbd->task_recv = NULL;

	spin_unlock_irqrestore(&nbd->tasks_lock, flags);



	if (signal_pending(current)) {

		ret = kernel_dequeue_signal(NULL);

		dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal %d\n",

			 task_pid_nr(current), current->comm, ret);

		mutex_lock(&nbd->tx_lock);

		sock_shutdown(nbd);

		mutex_unlock(&nbd->tx_lock);

		ret = -ETIMEDOUT;

	}



	return ret;

}
@@ -544,11 +571,8 @@ static int nbd_thread_send(void *data) 
{

	struct nbd_device *nbd = data;

	struct request *req;

	unsigned long flags;



	spin_lock_irqsave(&nbd->tasks_lock, flags);

	nbd->task_send = current;

	spin_unlock_irqrestore(&nbd->tasks_lock, flags);



	set_user_nice(current, MIN_NICE);

	while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) {
@@ -557,17 +581,6 @@ static int nbd_thread_send(void *data) 
					 kthread_should_stop() ||

					 !list_empty(&nbd->waiting_queue));



		if (signal_pending(current)) {

			int ret = kernel_dequeue_signal(NULL);



			dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal %d\n",

				 task_pid_nr(current), current->comm, ret);

			mutex_lock(&nbd->tx_lock);

			sock_shutdown(nbd);

			mutex_unlock(&nbd->tx_lock);

			break;

		}



		/* extract request */

		if (list_empty(&nbd->waiting_queue))

			continue;
@@ -582,13 +595,7 @@ static int nbd_thread_send(void *data) 
		nbd_handle_req(nbd, req);

	}



	spin_lock_irqsave(&nbd->tasks_lock, flags);

	nbd->task_send = NULL;

	spin_unlock_irqrestore(&nbd->tasks_lock, flags);



	/* Clear maybe pending signals */

	if (signal_pending(current))

		kernel_dequeue_signal(NULL);



	return 0;

}
@@ -618,7 +625,7 @@ static void nbd_request_handler(struct request_queue *q) 
			req, req->cmd_type);



		if (unlikely(!nbd->sock)) {

			dev_err(disk_to_dev(nbd->disk),

			dev_err_ratelimited(disk_to_dev(nbd->disk),

					    "Attempted send on closed socket\n");

			req->errors++;

			nbd_end_request(nbd, req);
@@ -636,6 +643,61 @@ static void nbd_request_handler(struct request_queue *q) 
	}

}



static int nbd_set_socket(struct nbd_device *nbd, struct socket *sock)

{

	int ret = 0;



	spin_lock_irq(&nbd->sock_lock);



	if (nbd->sock) {

		ret = -EBUSY;

		goto out;

	}



	nbd->sock = sock;



out:

	spin_unlock_irq(&nbd->sock_lock);



	return ret;

}



/* Reset all properties of an NBD device */

static void nbd_reset(struct nbd_device *nbd)

{

	nbd->disconnect = false;

	nbd->timedout = false;

	nbd->blksize = 1024;

	nbd->bytesize = 0;

	set_capacity(nbd->disk, 0);

	nbd->flags = 0;

	nbd->xmit_timeout = 0;

	queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);

	del_timer_sync(&nbd->timeout_timer);

}



static void nbd_bdev_reset(struct block_device *bdev)

{

	set_device_ro(bdev, false);

	bdev->bd_inode->i_size = 0;

	if (max_part > 0) {

		blkdev_reread_part(bdev);

		bdev->bd_invalidated = 1;

	}

}



static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev)

{

	if (nbd->flags & NBD_FLAG_READ_ONLY)

		set_device_ro(bdev, true);

	if (nbd->flags & NBD_FLAG_SEND_TRIM)

		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);

	if (nbd->flags & NBD_FLAG_SEND_FLUSH)

		blk_queue_flush(nbd->disk->queue, REQ_FLUSH);

	else

		blk_queue_flush(nbd->disk->queue, 0);

}



static int nbd_dev_dbg_init(struct nbd_device *nbd);

static void nbd_dev_dbg_close(struct nbd_device *nbd);
@@ -668,48 +730,41 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, 
		return 0;

	}

 

	case NBD_CLEAR_SOCK: {

		struct socket *sock = nbd->sock;

		nbd->sock = NULL;

	case NBD_CLEAR_SOCK:

		sock_shutdown(nbd);

		nbd_clear_que(nbd);

		BUG_ON(!list_empty(&nbd->queue_head));

		BUG_ON(!list_empty(&nbd->waiting_queue));

		kill_bdev(bdev);

		if (sock)

			sockfd_put(sock);

		return 0;

	}



	case NBD_SET_SOCK: {

		struct socket *sock;

		int err;

		if (nbd->sock)

			return -EBUSY;

		sock = sockfd_lookup(arg, &err);

		if (sock) {

			nbd->sock = sock;

			if (max_part > 0)

		struct socket *sock = sockfd_lookup(arg, &err);



		if (!sock)

			return err;



		err = nbd_set_socket(nbd, sock);

		if (!err && max_part)

			bdev->bd_invalidated = 1;

			nbd->disconnect = false; /* we're connected now */

			return 0;

		}

		return -EINVAL;



		return err;

	}



	case NBD_SET_BLKSIZE:

		nbd->blksize = arg;

		nbd->bytesize &= ~(nbd->blksize-1);

		bdev->bd_inode->i_size = nbd->bytesize;

		set_blocksize(bdev, nbd->blksize);

		set_capacity(nbd->disk, nbd->bytesize >> 9);

		return 0;

	case NBD_SET_BLKSIZE: {

		loff_t bsize = nbd->bytesize;

		do_div(bsize, arg);



		return nbd_size_set(nbd, bdev, arg, bsize);

	}



	case NBD_SET_SIZE:

		nbd->bytesize = arg & ~(nbd->blksize-1);

		bdev->bd_inode->i_size = nbd->bytesize;

		set_blocksize(bdev, nbd->blksize);

		set_capacity(nbd->disk, nbd->bytesize >> 9);

		return 0;

		return nbd_size_set(nbd, bdev, nbd->blksize,

				    arg / nbd->blksize);



	case NBD_SET_SIZE_BLOCKS:

		return nbd_size_set(nbd, bdev, nbd->blksize, arg);



	case NBD_SET_TIMEOUT:

		nbd->xmit_timeout = arg * HZ;
@@ -725,16 +780,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, 
		nbd->flags = arg;

		return 0;



	case NBD_SET_SIZE_BLOCKS:

		nbd->bytesize = ((u64) arg) * nbd->blksize;

		bdev->bd_inode->i_size = nbd->bytesize;

		set_blocksize(bdev, nbd->blksize);

		set_capacity(nbd->disk, nbd->bytesize >> 9);

		return 0;



	case NBD_DO_IT: {

		struct task_struct *thread;

		struct socket *sock;

		int error;



		if (nbd->task_recv)
@@ -744,15 +791,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, 


		mutex_unlock(&nbd->tx_lock);



		if (nbd->flags & NBD_FLAG_READ_ONLY)

			set_device_ro(bdev, true);

		if (nbd->flags & NBD_FLAG_SEND_TRIM)

			queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,

				nbd->disk->queue);

		if (nbd->flags & NBD_FLAG_SEND_FLUSH)

			blk_queue_flush(nbd->disk->queue, REQ_FLUSH);

		else

			blk_queue_flush(nbd->disk->queue, 0);

		nbd_parse_flags(nbd, bdev);



		thread = kthread_run(nbd_thread_send, nbd, "%s",

				     nbd_name(nbd));
@@ -762,29 +801,24 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, 
		}



		nbd_dev_dbg_init(nbd);

		error = nbd_thread_recv(nbd);

		error = nbd_thread_recv(nbd, bdev);

		nbd_dev_dbg_close(nbd);

		kthread_stop(thread);



		mutex_lock(&nbd->tx_lock);



		sock_shutdown(nbd);

		sock = nbd->sock;

		nbd->sock = NULL;

		nbd_clear_que(nbd);

		kill_bdev(bdev);

		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);

		set_device_ro(bdev, false);

		if (sock)

			sockfd_put(sock);

		nbd->flags = 0;

		nbd->bytesize = 0;

		bdev->bd_inode->i_size = 0;

		set_capacity(nbd->disk, 0);

		if (max_part > 0)

			blkdev_reread_part(bdev);

		nbd_bdev_reset(bdev);



		if (nbd->disconnect) /* user requested, ignore socket errors */

			return 0;

			error = 0;

		if (nbd->timedout)

			error = -ETIMEDOUT;



		nbd_reset(nbd);



		return error;

	}
@@ -892,50 +926,23 @@ static const struct file_operations nbd_dbg_flags_ops = { 
static int nbd_dev_dbg_init(struct nbd_device *nbd)

{

	struct dentry *dir;

	struct dentry *f;



	if (!nbd_dbg_dir)

		return -EIO;



	dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir);

	if (IS_ERR_OR_NULL(dir)) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s' (%ld)\n",

			nbd_name(nbd), PTR_ERR(dir));

		return PTR_ERR(dir);

	if (!dir) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n",

			nbd_name(nbd));

		return -EIO;

	}

	nbd->dbg_dir = dir;



	f = debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);

	if (IS_ERR_OR_NULL(f)) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'tasks', %ld\n",

			PTR_ERR(f));

		return PTR_ERR(f);

	}



	f = debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);

	if (IS_ERR_OR_NULL(f)) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'size_bytes', %ld\n",

			PTR_ERR(f));

		return PTR_ERR(f);

	}



	f = debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);

	if (IS_ERR_OR_NULL(f)) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'timeout', %ld\n",

			PTR_ERR(f));

		return PTR_ERR(f);

	}



	f = debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);

	if (IS_ERR_OR_NULL(f)) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'blocksize', %ld\n",

			PTR_ERR(f));

		return PTR_ERR(f);

	}



	f = debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops);

	if (IS_ERR_OR_NULL(f)) {

		dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'flags', %ld\n",

			PTR_ERR(f));

		return PTR_ERR(f);

	}

	debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);

	debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);

	debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);

	debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);

	debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops);



	return 0;

}
@@ -950,8 +957,8 @@ static int nbd_dbg_init(void) 
	struct dentry *dbg_dir;



	dbg_dir = debugfs_create_dir("nbd", NULL);

	if (IS_ERR(dbg_dir))

		return PTR_ERR(dbg_dir);

	if (!dbg_dir)

		return -EIO;



	nbd_dbg_dir = dbg_dir;
@@ -1069,7 +1076,7 @@ static int __init nbd_init(void) 
		nbd_dev[i].magic = NBD_MAGIC;

		INIT_LIST_HEAD(&nbd_dev[i].waiting_queue);

		spin_lock_init(&nbd_dev[i].queue_lock);

		spin_lock_init(&nbd_dev[i].tasks_lock);

		spin_lock_init(&nbd_dev[i].sock_lock);

		INIT_LIST_HEAD(&nbd_dev[i].queue_head);

		mutex_init(&nbd_dev[i].tx_lock);

		init_timer(&nbd_dev[i].timeout_timer);
@@ -1077,14 +1084,12 @@ static int __init nbd_init(void) 
		nbd_dev[i].timeout_timer.data = (unsigned long)&nbd_dev[i];

		init_waitqueue_head(&nbd_dev[i].active_wq);

		init_waitqueue_head(&nbd_dev[i].waiting_wq);

		nbd_dev[i].blksize = 1024;

		nbd_dev[i].bytesize = 0;

		disk->major = NBD_MAJOR;

		disk->first_minor = i << part_shift;

		disk->fops = &nbd_fops;

		disk->private_data = &nbd_dev[i];

		sprintf(disk->disk_name, "nbd%d", i);

		set_capacity(disk, 0);

		nbd_reset(&nbd_dev[i]);

		add_disk(disk);

	}