Re: [PATCH v3] RDMA/rtrs: Add missing deinit() call

[Jinpu Wang]

On Mon, Jan 6, 2025 at 1:45 AM Li Zhijian <lizhijian@xxxxxxxxxxx> wrote:
>
> A warning is triggered when repeatedly connecting and disconnecting the
> rnbd:
>  list_add corruption. prev->next should be next (ffff88800b13e480), but was ffff88801ecd1338. (prev=ffff88801ecd1340).
>  WARNING: CPU: 1 PID: 36562 at lib/list_debug.c:32 __list_add_valid_or_report+0x7f/0xa0
>  Workqueue: ib_cm cm_work_handler [ib_cm]
>  RIP: 0010:__list_add_valid_or_report+0x7f/0xa0
>   ? __list_add_valid_or_report+0x7f/0xa0
>   ib_register_event_handler+0x65/0x93 [ib_core]
>   rtrs_srv_ib_dev_init+0x29/0x30 [rtrs_server]
>   rtrs_ib_dev_find_or_add+0x124/0x1d0 [rtrs_core]
>   __alloc_path+0x46c/0x680 [rtrs_server]
>   ? rtrs_rdma_connect+0xa6/0x2d0 [rtrs_server]
>   ? rcu_is_watching+0xd/0x40
>   ? __mutex_lock+0x312/0xcf0
>   ? get_or_create_srv+0xad/0x310 [rtrs_server]
>   ? rtrs_rdma_connect+0xa6/0x2d0 [rtrs_server]
>   rtrs_rdma_connect+0x23c/0x2d0 [rtrs_server]
>   ? __lock_release+0x1b1/0x2d0
>   cma_cm_event_handler+0x4a/0x1a0 [rdma_cm]
>   cma_ib_req_handler+0x3a0/0x7e0 [rdma_cm]
>   cm_process_work+0x28/0x1a0 [ib_cm]
>   ? _raw_spin_unlock_irq+0x2f/0x50
>   cm_req_handler+0x618/0xa60 [ib_cm]
>   cm_work_handler+0x71/0x520 [ib_cm]
>
> Commit 667db86bcbe8 ("RDMA/rtrs: Register ib event handler") introduced a
> new element .deinit but never used it at all. Fix it by invoking the
> `deinit()` to appropriately unregister the IB event handler.
>
> Cc: Jinpu Wang <jinpu.wang@xxxxxxxxx>
> Fixes: 667db86bcbe8 ("RDMA/rtrs: Register ib event handler")
> Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
Thx!
Acked-by: Jack Wang <jinpu.wang@xxxxxxxxx>
> ---
> V3: Move deinit behind list_del # Jinpu Wang <jinpu.wang@xxxxxxxxx>
>
> V2: update the subject 'RDMA/ulp' -> 'RDMA/rtrs'
>     update commit log
> ---
>  drivers/infiniband/ulp/rtrs/rtrs.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs.c b/drivers/infiniband/ulp/rtrs/rtrs.c
> index 4e17d546d4cc..bf38ac6f87c4 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
> @@ -584,6 +584,9 @@ static void dev_free(struct kref *ref)
>         list_del(&dev->entry);
>         mutex_unlock(&pool->mutex);
>
> +       if (pool->ops && pool->ops->deinit)
> +               pool->ops->deinit(dev);
> +
>         ib_dealloc_pd(dev->ib_pd);
>         kfree(dev);
>  }
> --
> 2.47.0
>