From 09fb406a569b2f4b596048e1cfa2c92a35b8fc9b Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 6 May 2020 10:46:57 +0300 Subject: [PATCH] RDMA/cm: Add a note explaining how the timewait is eventually freed The way the cm_timewait_info is converted into a work and then freed is very subtle and surprising, add a note clarifying the lifetime here. Link: https://lore.kernel.org/r/20200506074701.9775-7-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/cm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 6a2a5f6..74c46b02 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -1025,6 +1025,11 @@ static void cm_enter_timewait(struct cm_id_private *cm_id_priv) msecs_to_jiffies(wait_time)); spin_unlock_irqrestore(&cm.lock, flags); + /* + * The timewait_info is converted into a work and gets freed during + * cm_free_work() in cm_timewait_handler(). + */ + BUILD_BUG_ON(offsetof(struct cm_timewait_info, work) != 0); cm_id_priv->timewait_info = NULL; } -- 2.7.4