RDMA/rdma_cm: Make rdma_addr_cancel into a fence

Currently rdma_addr_cancel does not prevent the callback from being used,
this is surprising and hard to reason about. There does not appear to be a
bug here as the only user of this API does refcount properly, fixing it
only to increase clarity.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Jason Gunthorpe 2018-04-03 07:52:03 +03:00
parent e19c0d2378
commit 44e75052bc

View file

@ -585,28 +585,30 @@ static void process_one_req(struct work_struct *_work)
} else if (req->status == -ENODATA) {
/* requeue the work for retrying again */
spin_lock_bh(&lock);
set_timeout(req, req->timeout);
if (!list_empty(&req->list))
set_timeout(req, req->timeout);
spin_unlock_bh(&lock);
return;
}
}
spin_lock_bh(&lock);
list_del(&req->list);
spin_unlock_bh(&lock);
/*
* Although the work will normally have been canceled by the
* workqueue, it can still be requeued as long as it is on the
* req_list, so it could have been requeued before we grabbed &lock.
* We need to cancel it after it is removed from req_list to really be
* sure it is safe to free.
*/
cancel_delayed_work(&req->work);
req->callback(req->status, (struct sockaddr *)&req->src_addr,
req->addr, req->context);
put_client(req->client);
kfree(req);
req->callback = NULL;
spin_lock_bh(&lock);
if (!list_empty(&req->list)) {
/*
* Although the work will normally have been canceled by the
* workqueue, it can still be requeued as long as it is on the
* req_list.
*/
cancel_delayed_work(&req->work);
list_del_init(&req->list);
put_client(req->client);
kfree(req);
}
spin_unlock_bh(&lock);
}
int rdma_resolve_ip(struct rdma_addr_client *client,
@ -691,17 +693,37 @@ int rdma_resolve_ip_route(struct sockaddr *src_addr,
void rdma_addr_cancel(struct rdma_dev_addr *addr)
{
struct addr_req *req, *temp_req;
struct addr_req *found = NULL;
spin_lock_bh(&lock);
list_for_each_entry_safe(req, temp_req, &req_list, list) {
if (req->addr == addr) {
req->status = -ECANCELED;
req->timeout = jiffies;
set_timeout(req, req->timeout);
/*
* Removing from the list means we take ownership of
* the req
*/
list_del_init(&req->list);
found = req;
break;
}
}
spin_unlock_bh(&lock);
if (!found)
return;
/*
* sync canceling the work after removing it from the req_list
* guarentees no work is running and none will be started.
*/
cancel_delayed_work_sync(&found->work);
if (found->callback)
found->callback(-ECANCELED, (struct sockaddr *)&found->src_addr,
found->addr, found->context);
put_client(found->client);
kfree(found);
}
EXPORT_SYMBOL(rdma_addr_cancel);