From 943bd984b108b3bb778790c2da4ae8d186b547e6 Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Thu, 2 May 2019 10:48:07 +0300 Subject: RDMA/core: Allow detaching gid attribute netdevice for RoCE When there is active traffic through a GID, a QP/AH holds reference to this GID entry. RoCE GID entry holds reference to its attached netdevice. Due to this when netdevice is deleted by admin user, its refcount is not dropped. Therefore, while deleting RoCE GID, wait for all GID attribute's netdev users to finish accessing netdev in rcu context. Once all users done accessing it, release the netdev refcount. Signed-off-by: Huy Nguyen Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/sysfs.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/infiniband/core/sysfs.c') diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c index 7a599c5e455f..8c7adc27aeea 100644 --- a/drivers/infiniband/core/sysfs.c +++ b/drivers/infiniband/core/sysfs.c @@ -349,10 +349,15 @@ static struct attribute *port_default_attrs[] = { static size_t print_ndev(const struct ib_gid_attr *gid_attr, char *buf) { - if (!gid_attr->ndev) - return -EINVAL; - - return sprintf(buf, "%s\n", gid_attr->ndev->name); + struct net_device *ndev; + size_t ret = -EINVAL; + + rcu_read_lock(); + ndev = rcu_dereference(gid_attr->ndev); + if (ndev) + ret = sprintf(buf, "%s\n", ndev->name); + rcu_read_unlock(); + return ret; } static size_t print_gid_type(const struct ib_gid_attr *gid_attr, char *buf) -- cgit v1.2.3