Re: [PATCH v2] RDMA/rtrs: Add missing deinit() call

["Zhijian Li (Fujitsu)" <lizhijian@fujitsu.com>]

On 04/01/2025 01:46, Jinpu Wang wrote:
> Hi Zhijian,
> 
> On Fri, Jan 3, 2025 at 4:08 AM Li Zhijian <lizhijian@fujitsu.com> 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.
>>
>> Fixes: 667db86bcbe8 ("RDMA/rtrs: Register ib event handler")
>> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
>> ---
>> 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..3b3efecd0817 100644
>> --- a/drivers/infiniband/ulp/rtrs/rtrs.c
>> +++ b/drivers/infiniband/ulp/rtrs/rtrs.c
>> @@ -580,6 +580,9 @@ static void dev_free(struct kref *ref)
>>          dev = container_of(ref, typeof(*dev), ref);
>>          pool = dev->pool;
>>
>> +       if (pool->ops && pool->ops->deinit)
>> +               pool->ops->deinit(dev);
>> +
>>          mutex_lock(&pool->mutex);
>>          list_del(&dev->entry);
>>          mutex_unlock(&pool->mutex);
> 
> Thx for the fix, I would suggest to move the change after list_del
> block, keep the opposite order from rtrs_ib_dev_find_or_add which do
> list_add as the last step, and then  if (pool->ops && pool->ops->init
> && pool->ops->init(dev)).

Make sense.
will update it soon.

Thanks


> 
> Regards!
> 
>> --
>> 2.47.0
>>