Re: [PATCH v4 for-next 06/12] RDMA/core: Use refcount_t instead of atomic_t on refcount of mcast_group
flat view
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2021-06-08 17:55:37
Subsystem:
infiniband subsystem, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds
On Fri, May 28, 2021 at 05:37:37PM +0800, Weihang Li wrote:
quoted hunk ↗ jump to hunk
@@ -565,8 +565,11 @@ static struct mcast_group *acquire_group(struct mcast_port *port, if (!is_mgid0) { spin_lock_irqsave(&port->lock, flags); group = mcast_find(port, mgid); - if (group) + if (group) { + refcount_inc(&group->refcount); goto found; + } + spin_unlock_irqrestore(&port->lock, flags); }@@ -590,8 +593,10 @@ static struct mcast_group *acquire_group(struct mcast_port *port, group = cur_group; } else refcount_inc(&port->refcount); + + refcount_set(&group->refcount, 1); +
This isn't right, when mcast_insert() returns an existing group we need to incr not set the refcount. Change it like this:
diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c
index 17abc212b87d05..cf99e17b81ce79 100644
--- a/drivers/infiniband/core/multicast.c
+++ b/drivers/infiniband/core/multicast.c@@ -585,17 +585,17 @@ static struct mcast_group *acquire_group(struct mcast_port *port, INIT_LIST_HEAD(&group->active_list); INIT_WORK(&group->work, mcast_work_handler); spin_lock_init(&group->lock); + refcount_set(&group->refcount, 1); spin_lock_irqsave(&port->lock, flags); cur_group = mcast_insert(port, group, is_mgid0); if (cur_group) { kfree(group); group = cur_group; + refcount_inc(&group->refcount); } else refcount_inc(&port->refcount); - refcount_set(&group->refcount, 1); - found: spin_unlock_irqrestore(&port->lock, flags); return group;