2022-01-04 10:10 GMT+09:00, Hyunchul Lee <hyc.lee@xxxxxxxxx>:
> 2022년 1월 4일 (화) 오전 9:45, Namjae Jeon <linkinjeon@xxxxxxxxxx>님이 작성:
>>
>> 2022-01-03 9:02 GMT+09:00, Hyunchul Lee <hyc.lee@xxxxxxxxx>:
>> > if CONFIG_LOCKDEP is enabled, the following
>> > kernel warning message is generated because
>> > rdma_accept() is called not under CM(Connection
>> > Manager) handler.
>> >
>> > [ 63.211405 ] WARNING: CPU: 1 PID: 345 at
>> > drivers/infiniband/core/cma.c:4405 rdma_accept+0x17a/0x350
>> > [ 63.212080 ] RIP: 0010:rdma_accept+0x17a/0x350
>> > ...
>> > [ 63.214036 ] Call Trace:
>> > [ 63.214098 ] <TASK>
>> > [ 63.214185 ] smb_direct_accept_client+0xb4/0x170 [ksmbd]
>> > [ 63.214412 ] smb_direct_prepare+0x322/0x8c0 [ksmbd]
>> > [ 63.214555 ] ? rcu_read_lock_sched_held+0x3a/0x70
>> > [ 63.214700 ] ksmbd_conn_handler_loop+0x63/0x270 [ksmbd]
>> > [ 63.214826 ] ? ksmbd_conn_alive+0x80/0x80 [ksmbd]
>> > [ 63.214952 ] kthread+0x171/0x1a0
>> > [ 63.215039 ] ? set_kthread_struct+0x40/0x40
>> > [ 63.215128 ] ret_from_fork+0x22/0x30
>> I could not understand why lockdep trigger this warning.
>> Could you elaborate more ?
>>
>
> rdma_accept checks whether the handler_mutex is held. if not,
> this warning is generated. And CM holds the handler_mutex before
> ksmbd's handler callback is called.
Okay, please update patch description with this.
>
>> >
>> > To avoid this, move creating a queue pair and accepting
>> > a client from transport_ops->prepare() to
>> > smb_direct_handle_connect_request().
>> >
>> > Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
>> > ---
>> > fs/ksmbd/transport_rdma.c | 97 +++++++++++++++++++++++----------------
>> > 1 file changed, 57 insertions(+), 40 deletions(-)
>> >
>> > diff --git a/fs/ksmbd/transport_rdma.c b/fs/ksmbd/transport_rdma.c
>> > index f89b64e27836..b37e4b9580ae 100644
>> > --- a/fs/ksmbd/transport_rdma.c
>> > +++ b/fs/ksmbd/transport_rdma.c
>> > @@ -568,6 +568,7 @@ static void recv_done(struct ib_cq *cq, struct
>> > ib_wc
>> > *wc)
>> > }
>> > t->negotiation_requested = true;
>> > t->full_packet_received = true;
>> > + enqueue_reassembly(t, recvmsg, 0);
>> Is this a fix related to this patch?
>
> Yes, this is required to receive the negotiation request
> from a client.
> Before this patch, posting a buffer and waiting for
> the request is done in a function. Because
> we have the reference of the buffer, we don't need to
> append it into the queue.
Okay.
>
>
>> > wake_up_interruptible(&t->wait_status);
>> > break;
>> > case SMB_DIRECT_MSG_DATA_TRANSFER: {
>> > @@ -1594,19 +1595,13 @@ static int smb_direct_accept_client(struct
>> > smb_direct_transport *t)
>> > pr_err("error at rdma_accept: %d\n", ret);
>> > return ret;
>> > }
>> > -
>> > - wait_event_interruptible(t->wait_status,
>> > - t->status != SMB_DIRECT_CS_NEW);
>> > - if (t->status != SMB_DIRECT_CS_CONNECTED)
>> > - return -ENOTCONN;
>> > return 0;
>> > }
>> >
>> > -static int smb_direct_negotiate(struct smb_direct_transport *t)
>> > +static int smb_direct_prepare_negotiation(struct smb_direct_transport
>> > *t)
>> > {
>> > int ret;
>> > struct smb_direct_recvmsg *recvmsg;
>> > - struct smb_direct_negotiate_req *req;
>> >
>> > recvmsg = get_free_recvmsg(t);
>> > if (!recvmsg)
>> > @@ -1616,44 +1611,20 @@ static int smb_direct_negotiate(struct
>> > smb_direct_transport *t)
>> > ret = smb_direct_post_recv(t, recvmsg);
>> > if (ret) {
>> > pr_err("Can't post recv: %d\n", ret);
>> > - goto out;
>> > + goto out_err;
>> > }
>> >
>> > t->negotiation_requested = false;
>> > ret = smb_direct_accept_client(t);
>> > if (ret) {
>> > pr_err("Can't accept client\n");
>> > - goto out;
>> > + goto out_err;
>> > }
>> >
>> > smb_direct_post_recv_credits(&t->post_recv_credits_work.work);
>> > -
>> > - ksmbd_debug(RDMA, "Waiting for SMB_DIRECT negotiate request\n");
>> > - ret = wait_event_interruptible_timeout(t->wait_status,
>> > - t->negotiation_requested
>> > ||
>> > - t->status ==
>> > SMB_DIRECT_CS_DISCONNECTED,
>> > -
>> > SMB_DIRECT_NEGOTIATE_TIMEOUT * HZ);
>> > - if (ret <= 0 || t->status == SMB_DIRECT_CS_DISCONNECTED) {
>> > - ret = ret < 0 ? ret : -ETIMEDOUT;
>> > - goto out;
>> > - }
>> > -
>> > - ret = smb_direct_check_recvmsg(recvmsg);
>> > - if (ret == -ECONNABORTED)
>> > - goto out;
>> > -
>> > - req = (struct smb_direct_negotiate_req *)recvmsg->packet;
>> > - t->max_recv_size = min_t(int, t->max_recv_size,
>> > - le32_to_cpu(req->preferred_send_size));
>> > - t->max_send_size = min_t(int, t->max_send_size,
>> > - le32_to_cpu(req->max_receive_size));
>> > - t->max_fragmented_send_size =
>> > - le32_to_cpu(req->max_fragmented_size);
>> > -
>> > - ret = smb_direct_send_negotiate_response(t, ret);
>> > -out:
>> > - if (recvmsg)
>> > - put_recvmsg(t, recvmsg);
>> > + return 0;
>> > +out_err:
>> > + put_recvmsg(t, recvmsg);
>> > return ret;
>> > }
>> >
>> > @@ -1890,6 +1861,47 @@ static int smb_direct_create_qpair(struct
>> > smb_direct_transport *t,
>> > static int smb_direct_prepare(struct ksmbd_transport *t)
>> > {
>> > struct smb_direct_transport *st = smb_trans_direct_transfort(t);
>> > + struct smb_direct_recvmsg *recvmsg;
>> > + struct smb_direct_negotiate_req *req;
>> > + int ret;
>> > +
>> > + ksmbd_debug(RDMA, "Waiting for SMB_DIRECT negotiate request\n");
>> > + ret = wait_event_interruptible_timeout(st->wait_status,
>> > + st->negotiation_requested
>> > ||
>> > + st->status ==
>> > SMB_DIRECT_CS_DISCONNECTED,
>> > +
>> > SMB_DIRECT_NEGOTIATE_TIMEOUT * HZ);
>> > + if (ret <= 0 || st->status == SMB_DIRECT_CS_DISCONNECTED)
>> > + return ret < 0 ? ret : -ETIMEDOUT;
>> > +
>> > + recvmsg = get_first_reassembly(st);
>> > + if (!recvmsg)
>> > + return -ECONNABORTED;
>> > +
>> > + ret = smb_direct_check_recvmsg(recvmsg);
>> > + if (ret == -ECONNABORTED)
>> > + goto out;
>> > +
>> > + req = (struct smb_direct_negotiate_req *)recvmsg->packet;
>> > + st->max_recv_size = min_t(int, st->max_recv_size,
>> > + le32_to_cpu(req->preferred_send_size));
>> > + st->max_send_size = min_t(int, st->max_send_size,
>> > + le32_to_cpu(req->max_receive_size));
>> > + st->max_fragmented_send_size =
>> > + le32_to_cpu(req->max_fragmented_size);
>> > +
>> > + ret = smb_direct_send_negotiate_response(st, ret);
>> > +out:
>> > + spin_lock_irq(&st->reassembly_queue_lock);
>> > + st->reassembly_queue_length--;
>> > + list_del(&recvmsg->list);
>> > + spin_unlock_irq(&st->reassembly_queue_lock);
>> > + put_recvmsg(st, recvmsg);
>> > +
>> > + return ret;
>> > +}
>> > +
>> > +static int smb_direct_connect(struct smb_direct_transport *st)
>> > +{
>> > int ret;
>> > struct ib_qp_cap qp_cap;
>> >
>> > @@ -1911,13 +1923,11 @@ static int smb_direct_prepare(struct
>> > ksmbd_transport
>> > *t)
>> > return ret;
>> > }
>> >
>> > - ret = smb_direct_negotiate(st);
>> > + ret = smb_direct_prepare_negotiation(st);
>> > if (ret) {
>> > pr_err("Can't negotiate: %d\n", ret);
>> > return ret;
>> > }
>> > -
>> > - st->status = SMB_DIRECT_CS_CONNECTED;
>> > return 0;
>> > }
>> >
>> > @@ -1933,6 +1943,7 @@ static bool rdma_frwr_is_supported(struct
>> > ib_device_attr *attrs)
>> > static int smb_direct_handle_connect_request(struct rdma_cm_id
>> > *new_cm_id)
>> > {
>> > struct smb_direct_transport *t;
>> > + int ret;
>> >
>> > if (!rdma_frwr_is_supported(&new_cm_id->device->attrs)) {
>> > ksmbd_debug(RDMA,
>> > @@ -1945,11 +1956,17 @@ static int
>> > smb_direct_handle_connect_request(struct
>> > rdma_cm_id *new_cm_id)
>> > if (!t)
>> > return -ENOMEM;
>> >
>> > + ret = smb_direct_connect(t);
>> > + if (ret) {
>> > + free_transport(t);
>> > + return ret;
>> I think that it is better to use goto statement to out after freeing
>> transport structure.
>
> Okay, I will change it.
OK.
Thanks.
>
>> > + }
>> > +
>> > KSMBD_TRANS(t)->handler = kthread_run(ksmbd_conn_handler_loop,
>> > KSMBD_TRANS(t)->conn,
>> > "ksmbd:r%u",
>> > smb_direct_port);
>> > if (IS_ERR(KSMBD_TRANS(t)->handler)) {
>> > - int ret = PTR_ERR(KSMBD_TRANS(t)->handler);
>> > + ret = PTR_ERR(KSMBD_TRANS(t)->handler);
>> >
>> > pr_err("Can't start thread\n");
>> > free_transport(t);
>> > --
>> > 2.25.1
>> >
>> >
>
>
>
> --
> Thanks,
> Hyunchul
>
