Re: [PATCH 03/62] drbd: Balance RCU calls in drbd_adm_dump_devices()

["Christoph Böhmwalder" <christoph.boehmwalder@linbit.com>]

Am 23.02.26 um 22:48 schrieb Bart Van Assche:
> Make drbd_adm_dump_devices() call rcu_read_lock() before
> rcu_read_unlock() is called. This has been detected by the Clang
> thread-safety analyzer. Compile-tested only.
> 
> Cc: Andreas Gruenbacher <agruen@linbit.com>
> Cc: linux-block@vger.kernel.org
> Fixes: a55bbd375d18 ("drbd: Backport the "status" command")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  drivers/block/drbd/drbd_nl.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
> index e201f0087a0f..728ecc431b38 100644
> --- a/drivers/block/drbd/drbd_nl.c
> +++ b/drivers/block/drbd/drbd_nl.c
> @@ -3378,8 +3378,10 @@ int drbd_adm_dump_devices(struct sk_buff *skb, struct netlink_callback *cb)
>  		if (resource_filter) {
>  			retcode = ERR_RES_NOT_KNOWN;
>  			resource = drbd_find_resource(nla_data(resource_filter));
> -			if (!resource)
> +			if (!resource) {
> +				rcu_read_lock();
>  				goto put_result;
> +			}
>  			cb->args[0] = (long)resource;
>  		}
>  	}
> @@ -3628,8 +3630,10 @@ int drbd_adm_dump_peer_devices(struct sk_buff *skb, struct netlink_callback *cb)
>  		if (resource_filter) {
>  			retcode = ERR_RES_NOT_KNOWN;
>  			resource = drbd_find_resource(nla_data(resource_filter));
> -			if (!resource)
> +			if (!resource) {
> +				rcu_read_lock();
>  				goto put_result;
> +			}
>  		}
>  		cb->args[0] = (long)resource;
>  	}
> 

Passes our internal DRBD test suite.

Tested-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>

-- 
Christoph Böhmwalder
LINBIT | Keeping the Digital World Running
DRBD HA —  Disaster Recovery — Software defined Storage