[PATCH net-next] netdevsim: Protect both reload_down and reload_up paths

From: Leon Romanovsky
Date: Thu Aug 05 2021 - 10:34:37 EST


From: Leon Romanovsky <leonro@xxxxxxxxxx>

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@xxxxxxxxxx>
---
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(-)

diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c
index a29ec264119d..62d033a1a557 100644
--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -196,6 +196,11 @@ new_port_store(struct device *dev, struct device_attribute *attr,
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, struct device_attribute *attr,
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;
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index ff5714209b86..53068e184c90 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -878,6 +878,7 @@ static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
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 devlink *devlink, enum devlink_reload_actio
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,
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 1c20bcbd9d91..793c86dc5a9c 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -362,6 +362,7 @@ 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;
};

--
2.31.1