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Commit 2d7091bc authored by Bart Van Assche's avatar Bart Van Assche Committed by Roland Dreier
Browse files

IB/srp: Avoid duplicate connections 



The connection uniqueness check is performed before a new connection
is added to the target list. This patch protects both actions by a
mutex such that simultaneous writes from two different threads into the
"add_target" variable do not result in duplicate connections.

Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent e7ffde01

drivers/infiniband/ulp/srp/ib_srp.c

+9 −3
Original line number Diff line number Diff line
@@ -2614,6 +2614,8 @@ static ssize_t srp_create_target(struct device *dev, 
	target->tl_retry_count	= 7;

	target->queue_size	= SRP_DEFAULT_QUEUE_SIZE;



	mutex_lock(&host->add_target_mutex);



	ret = srp_parse_options(buf, target);

	if (ret)

		goto err;
@@ -2682,7 +2684,11 @@ static ssize_t srp_create_target(struct device *dev, 
		     be64_to_cpu(target->service_id),

		     target->path.sgid.raw, target->path.dgid.raw);



	return count;

	ret = count;



out:

	mutex_unlock(&host->add_target_mutex);

	return ret;



err_disconnect:

	srp_disconnect_target(target);
@@ -2698,8 +2704,7 @@ err_free_mem: 


err:

	scsi_host_put(target_host);



	return ret;

	goto out;

}



static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
@@ -2735,6 +2740,7 @@ static struct srp_host *srp_add_port(struct srp_device *device, u8 port) 
	INIT_LIST_HEAD(&host->target_list);

	spin_lock_init(&host->target_lock);

	init_completion(&host->released);

	mutex_init(&host->add_target_mutex);

	host->srp_dev = device;

	host->port = port;

drivers/infiniband/ulp/srp/ib_srp.h

+1 −0
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ struct srp_host { 
	spinlock_t		target_lock;

	struct completion	released;

	struct list_head	list;

	struct mutex		add_target_mutex;

};



struct srp_request {