Re: [PATCH net-next v5 1/5] netdevsim: maintain a list of probed netdevsims

[Jiri Pirko <jiri@resnulli.us>]

Thu, Dec 28, 2023 at 02:46:29AM CET, dw@davidwei.uk wrote:
>In this patch I added a linked list nsim_dev_list of probed nsim_devs,
>added during nsim_drv_probe() and removed during nsim_drv_remove(). A
>mutex nsim_dev_list_lock protects the list.
>
>Signed-off-by: David Wei <dw@davidwei.uk>
>---
> drivers/net/netdevsim/dev.c       | 19 +++++++++++++++++++
> drivers/net/netdevsim/netdevsim.h |  1 +
> 2 files changed, 20 insertions(+)
>
>diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
>index b4d3b9cde8bd..8d477aa99f94 100644
>--- a/drivers/net/netdevsim/dev.c
>+++ b/drivers/net/netdevsim/dev.c
>@@ -35,6 +35,9 @@
> 
> #include "netdevsim.h"
> 
>+static LIST_HEAD(nsim_dev_list);
>+static DEFINE_MUTEX(nsim_dev_list_lock);
>+
> static unsigned int
> nsim_dev_port_index(enum nsim_dev_port_type type, unsigned int port_index)
> {
>@@ -1607,6 +1610,11 @@ int nsim_drv_probe(struct nsim_bus_dev *nsim_bus_dev)
> 
> 	nsim_dev->esw_mode = DEVLINK_ESWITCH_MODE_LEGACY;
> 	devl_unlock(devlink);
>+
>+	mutex_lock(&nsim_dev_list_lock);
>+	list_add(&nsim_dev->list, &nsim_dev_list);
>+	mutex_unlock(&nsim_dev_list_lock);
>+
> 	return 0;
> 
> err_hwstats_exit:
>@@ -1668,8 +1676,19 @@ void nsim_drv_remove(struct nsim_bus_dev *nsim_bus_dev)
> {
> 	struct nsim_dev *nsim_dev = dev_get_drvdata(&nsim_bus_dev->dev);
> 	struct devlink *devlink = priv_to_devlink(nsim_dev);
>+	struct nsim_dev *pos, *tmp;
>+
>+	mutex_lock(&nsim_dev_list_lock);
>+	list_for_each_entry_safe(pos, tmp, &nsim_dev_list, list) {
>+		if (pos == nsim_dev) {
>+			list_del(&nsim_dev->list);
>+			break;
>+		}
>+	}
>+	mutex_unlock(&nsim_dev_list_lock);

This is just:
	mutex_lock(&nsim_dev_list_lock);
	list_del(&nsim_dev->list);
	mutex_unlock(&nsim_dev_list_lock);

The loop is not good for anything.



> 
> 	devl_lock(devlink);
>+

Remove this leftover line addition.


> 	nsim_dev_reload_destroy(nsim_dev);
> 
> 	nsim_bpf_dev_exit(nsim_dev);
>diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
>index 028c825b86db..babb61d7790b 100644
>--- a/drivers/net/netdevsim/netdevsim.h
>+++ b/drivers/net/netdevsim/netdevsim.h
>@@ -277,6 +277,7 @@ struct nsim_vf_config {
> 
> struct nsim_dev {
> 	struct nsim_bus_dev *nsim_bus_dev;
>+	struct list_head list;
> 	struct nsim_fib_data *fib_data;
> 	struct nsim_trap_data *trap_data;
> 	struct dentry *ddir;
>-- 
>2.39.3
>