From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
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: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/core/addr.c | 58 +++++++++++++++++++++++++++++-------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index c7e8cfb5689c..beb1a35d51e7 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -583,28 +583,30 @@ 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,
@@ -690,17 +692,37 @@ EXPORT_SYMBOL(rdma_resolve_ip_route);
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);
--
2.14.3
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