From: Kaike Wan <[email protected]> It was found by Saurabh Sengar that the netlink code tried to allocate memory with GFP_KERNEL while holding a spinlock. While it is possible to fix the issue by replacing GFP_KERNEL with GFP_ATOMIC, it is better to get rid of the spinlock while sending the packet. However, in order to protect against a race condition that a quick response may be received before the request is put on the request list, we need to put the request on the list first.
Signed-off-by: Kaike Wan <[email protected]> --- drivers/infiniband/core/sa_query.c | 22 ++++++++++++---------- 1 files changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index edcf568..240b57c 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -562,23 +562,25 @@ static int ib_nl_make_request(struct ib_sa_query *query) INIT_LIST_HEAD(&query->list); query->seq = (u32)atomic_inc_return(&ib_nl_sa_request_seq); + /* Put the request on the list first.*/ spin_lock_irqsave(&ib_nl_request_lock, flags); + delay = msecs_to_jiffies(sa_local_svc_timeout_ms); + query->timeout = delay + jiffies; + list_add_tail(&query->list, &ib_nl_request_list); + spin_unlock_irqrestore(&ib_nl_request_lock, flags); + ret = ib_nl_send_msg(query); + spin_lock_irqsave(&ib_nl_request_lock, flags); if (ret <= 0) { ret = -EIO; - goto request_out; + /* Remove the request */ + list_del(&query->list); } else { ret = 0; + /* Start the timeout if this is the only request */ + if (ib_nl_request_list.next == &query->list) + queue_delayed_work(ib_nl_wq, &ib_nl_timed_work, delay); } - - delay = msecs_to_jiffies(sa_local_svc_timeout_ms); - query->timeout = delay + jiffies; - list_add_tail(&query->list, &ib_nl_request_list); - /* Start the timeout if this is the only request */ - if (ib_nl_request_list.next == &query->list) - queue_delayed_work(ib_nl_wq, &ib_nl_timed_work, delay); - -request_out: spin_unlock_irqrestore(&ib_nl_request_lock, flags); return ret; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
