From: Leon Romanovsky <leonro@nvidia.com>
Date: Thu, 5 Aug 2021 17:34:28 +0300
Subject: netdevsim: Protect both reload_down and reload_up paths
Patch-mainline: v5.15-rc1
Git-commit: 5c0418ed16109759c7aec86b72f9bf56a0358526
References: jsc#SLE-19253

Don't progress with adding and deleting ports as long as devlink
reload is running.

Fixes: 23809a726c0d ("netdevsim: Forbid devlink reload when adding or deleting ports")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/netdevsim/bus.c       |   10 ++++++++++
 drivers/net/netdevsim/dev.c       |   12 +++++++++++-
 drivers/net/netdevsim/netdevsim.h |    1 +
 3 files changed, 22 insertions(+), 1 deletion(-)

--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -196,6 +196,11 @@ new_port_store(struct device *dev, struc
 	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
 		return -EBUSY;
 
+	if (nsim_bus_dev->in_reload) {
+		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
+		return -EBUSY;
+	}
+
 	ret = nsim_dev_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
 	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 	return ret ? ret : count;
@@ -221,6 +226,11 @@ del_port_store(struct device *dev, struc
 	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
 		return -EBUSY;
 
+	if (nsim_bus_dev->in_reload) {
+		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
+		return -EBUSY;
+	}
+
 	ret = nsim_dev_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
 	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 	return ret ? ret : count;
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -878,6 +878,7 @@ static int nsim_dev_reload_down(struct d
 		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 		return -EOPNOTSUPP;
 	}
+	nsim_bus_dev->in_reload = true;
 
 	nsim_dev_reload_destroy(nsim_dev);
 	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
@@ -889,17 +890,26 @@ static int nsim_dev_reload_up(struct dev
 			      struct netlink_ext_ack *extack)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
+	struct nsim_bus_dev *nsim_bus_dev;
+	int ret;
+
+	nsim_bus_dev = nsim_dev->nsim_bus_dev;
+	mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
+	nsim_bus_dev->in_reload = false;
 
 	if (nsim_dev->fail_reload) {
 		/* For testing purposes, user set debugfs fail_reload
 		 * value to true. Fail right away.
 		 */
 		NL_SET_ERR_MSG_MOD(extack, "User setup the reload to fail for testing purposes");
+		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 		return -EINVAL;
 	}
 
 	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
-	return nsim_dev_reload_create(nsim_dev, extack);
+	ret = nsim_dev_reload_create(nsim_dev, extack);
+	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
+	return ret;
 }
 
 static int nsim_dev_info_get(struct devlink *devlink,
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -361,6 +361,7 @@ struct nsim_bus_dev {
 	struct nsim_vf_config *vfconfigs;
 	/* Lock for devlink->reload_enabled in netdevsim module */
 	struct mutex nsim_bus_reload_lock;
+	bool in_reload;
 	bool init;
 };