Thank you for your contribution! Sashiko AI review found 1 potential issue(s) 
to consider:

Pre-existing issues:
- [High] The boolean flag `apc->channel_changing` is used as an open-coded, 
ad-hoc lock to protect vport reconfiguration against concurrent RDMA access, 
violating core kernel locking rules.
--

--- Patch [4]: [PATCH net-next v2 04/13] net: mana: swap queue sets in 
mana_set_priv_flags ---
commit 922132e276d163d3c58e43d88b85f6b85a403949
Author: Long Li <[email protected]>

net: mana: swap queue sets in mana_set_priv_flags

This commit modifies mana_set_priv_flags to pre-allocate and swap queue sets
instead of rebuilding them in place. This ensures that if the rebuild fails,
both the queues and the flag word remain untouched.

> diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c 
> b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
[ ... ]
> @@ -884,54 +888,53 @@ static int mana_set_priv_flags(struct net_device *ndev, 
> u32 priv_flags)
[ ... ]
> -             /* Block RDMA from grabbing the vport during detach/attach */
> -             mutex_lock(&apc->vport_mutex);
> -             apc->channel_changing = true;
> +     /* Block RDMA from acquiring the vport for the duration. */
> +     mutex_lock(&apc->vport_mutex);
> +     if (apc->channel_changing) {
>               mutex_unlock(&apc->vport_mutex);
> +             return -EBUSY;
> +     }
> +     apc->channel_changing = true;
> +     mutex_unlock(&apc->vport_mutex);

[Severity: High]
This is a pre-existing issue, but in mana_set_priv_flags, is using a boolean
flag like apc->channel_changing as an open-coded trylock safe?

It appears to be set on entry here and cleared on exit to protect vport
reconfiguration against concurrent RDMA access, rather than using a standard
synchronization primitive. Does this ad-hoc locking pattern evade lockdep
and risk races since it bypasses proper kernel locking rules?

[ ... ]
> clear_flag:
>       mutex_lock(&apc->vport_mutex);
>       apc->channel_changing = false;
>       mutex_unlock(&apc->vport_mutex);
> -
>       return err;
>  }

-- 
Sashiko AI review ยท 
https://sashiko.dev/#/patchset/[email protected]?part=4

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