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Commit 3e4d60a8 authored by Sasha Levin's avatar Sasha Levin Committed by Roland Dreier
Browse files

RDMA/ocrdma: Don't sleep in atomic notifier handler 



Events sent to ocrdma_inet6addr_event() are sent from an atomic context,
therefore we can't try to lock a mutex within the notifier callback.

We could just switch the mutex to a spinlock since all it does it
protect a list, but I've gone ahead and switched the list to use RCU
instead.  I couldn't fully test it since I don't have IB hardware, so
if it doesn't fully work for some reason let me know and I'll switch
it back to using a spinlock.

Signed-off-by: default avatarSasha Levin <levinsasha928@gmail.com>

[ Fixed locking in ocrdma_add().  - Roland ]

Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent c592c423

drivers/infiniband/hw/ocrdma/ocrdma.h

+1 −0
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ struct ocrdma_dev { 
	struct be_dev_info nic_info;



	struct list_head entry;

	struct rcu_head rcu;

	int id;

};

drivers/infiniband/hw/ocrdma/ocrdma_main.c

+22 −16
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ MODULE_AUTHOR("Emulex Corporation"); 
MODULE_LICENSE("GPL");



static LIST_HEAD(ocrdma_dev_list);

static DEFINE_MUTEX(ocrdma_devlist_lock);

static DEFINE_SPINLOCK(ocrdma_devlist_lock);

static DEFINE_IDR(ocrdma_dev_id);



static union ib_gid ocrdma_zero_sgid;
@@ -221,14 +221,14 @@ static int ocrdma_inet6addr_event(struct notifier_block *notifier, 
		is_vlan = true;

		vid = vlan_dev_vlan_id(event_netdev);

	}

	mutex_lock(&ocrdma_devlist_lock);

	list_for_each_entry(dev, &ocrdma_dev_list, entry) {

	rcu_read_lock();

	list_for_each_entry_rcu(dev, &ocrdma_dev_list, entry) {

		if (dev->nic_info.netdev == netdev) {

			found = true;

			break;

		}

	}

	mutex_unlock(&ocrdma_devlist_lock);

	rcu_read_unlock();



	if (!found)

		return NOTIFY_DONE;
@@ -431,9 +431,9 @@ static struct ocrdma_dev *ocrdma_add(struct be_dev_info *dev_info) 
	if (status)

		goto alloc_err;



	mutex_lock(&ocrdma_devlist_lock);

	list_add_tail(&dev->entry, &ocrdma_dev_list);

	mutex_unlock(&ocrdma_devlist_lock);

	spin_lock(&ocrdma_devlist_lock);

	list_add_tail_rcu(&dev->entry, &ocrdma_dev_list);

	spin_unlock(&ocrdma_devlist_lock);

	return dev;



alloc_err:
@@ -448,16 +448,9 @@ static struct ocrdma_dev *ocrdma_add(struct be_dev_info *dev_info) 
	return NULL;

}



static void ocrdma_remove(struct ocrdma_dev *dev)

static void ocrdma_remove_free(struct rcu_head *rcu)

{

	/* first unregister with stack to stop all the active traffic

	 * of the registered clients.

	 */

	ib_unregister_device(&dev->ibdev);



	mutex_lock(&ocrdma_devlist_lock);

	list_del(&dev->entry);

	mutex_unlock(&ocrdma_devlist_lock);

	struct ocrdma_dev *dev = container_of(rcu, struct ocrdma_dev, rcu);



	ocrdma_free_resources(dev);

	ocrdma_cleanup_hw(dev);
@@ -467,6 +460,19 @@ static void ocrdma_remove(struct ocrdma_dev *dev) 
	ib_dealloc_device(&dev->ibdev);

}



static void ocrdma_remove(struct ocrdma_dev *dev)

{

	/* first unregister with stack to stop all the active traffic

	 * of the registered clients.

	 */

	ib_unregister_device(&dev->ibdev);



	spin_lock(&ocrdma_devlist_lock);

	list_del_rcu(&dev->entry);

	spin_unlock(&ocrdma_devlist_lock);

	call_rcu(&dev->rcu, ocrdma_remove_free);

}



static int ocrdma_open(struct ocrdma_dev *dev)

{

	struct ib_event port_event;