Re: [Patch v3 03/12] net: mana: Handle vport sharing between devices
From: David Miller
Date: Mon Jun 13 2022 - 06:55:36 EST
From: longli@xxxxxxxxxxxxxxxxx
Date: Sun, 12 Jun 2022 14:14:45 -0700
> +int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
> + u32 doorbell_pg_id)
> {
> + /* Ethernet driver and IB driver can't take the port at the same time */
> + refcount_inc(&apc->port_use_count);
> + if (refcount_read(&apc->port_use_count) > 2) {
This is a racy test, the count could change after the test against
'2'. It would be nice if there was a primitive to do the increment
and test atomically, but I fail to see one that matches this scenerio
currently.
Thank you.