From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 245F3C77B70 for ; Tue, 11 Apr 2023 12:27:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229950AbjDKM1D (ORCPT ); Tue, 11 Apr 2023 08:27:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229873AbjDKM1B (ORCPT ); Tue, 11 Apr 2023 08:27:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B01E240F8; Tue, 11 Apr 2023 05:26:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4C34F6241E; Tue, 11 Apr 2023 12:26:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 326C8C433EF; Tue, 11 Apr 2023 12:26:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681216015; bh=h+Bk8l0bcNtue5rAI32PLmr4ljUzbsE0ynITbU7dios=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GAzuf5XsnUV+nDmFC6q2/SA+oFGfynM8smMf6cxYLJonkRmH3zEhu4IbISadU4eyl TECvrUcVGaLPoQlP+8H7PPVyb7raAMss43lwg88UvmrUcGr7EfIxphw7c3BMKhSpVZ 4VN4Pfo69Xa1Uvi6UCWiYpalebe+z4ctULdo2kBxnJ5M0loofu7fkQ8nYlwmup7OaK w/0gsaXYVOK+ATCt7aSciJ4y1ls5vAJVzFzHZVUAHRuVcdhC2lZSNPZUCvRMb498hu NJezOYPxtCo/tiNnF44NFqDwMXnDNoHGdDfetK8BHJImKoqL2I9PeXrpmIRzZ8HJMQ gaYfhPvditGGg== Date: Tue, 11 Apr 2023 15:26:51 +0300 From: Leon Romanovsky To: "Zhijian Li (Fujitsu)" Cc: Guoqing Jiang , "haris.iqbal@ionos.com" , "jinpu.wang@ionos.com" , "jgg@ziepe.ca" , "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH for-next 2/3] RDMA/rtrs: Fix rxe_dealloc_pd warning Message-ID: <20230411122651.GV182481@unreal> References: <1681108984-2-1-git-send-email-lizhijian@fujitsu.com> <1681108984-2-3-git-send-email-lizhijian@fujitsu.com> <20230410120809.GN182481@unreal> <0d9c57db-bca3-adb4-71fd-7362e4842917@linux.dev> <85323eb2-cfc7-d1b8-3a75-3fa63dde29db@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <85323eb2-cfc7-d1b8-3a75-3fa63dde29db@fujitsu.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 11, 2023 at 02:43:46AM +0000, Zhijian Li (Fujitsu) wrote: > > > On 10/04/2023 21:10, Guoqing Jiang wrote: > > > > > > On 4/10/23 20:08, Leon Romanovsky wrote: > >> On Mon, Apr 10, 2023 at 06:43:03AM +0000, Li Zhijian wrote: > >>> The warning occurs when destroying PD whose reference count is not zero. > >>> > >>> Precodition: clt_path->s.con_num is 2. > >>> So 2 cm connection will be created as below: > >>> CPU0                                              CPU1 > >>> init_conns {                              | > >>>    create_cm() // a. con[0] created        | > >>>                                            |  a'. rtrs_clt_rdma_cm_handler() { > >>>                                            |    rtrs_rdma_addr_resolved() > >>>                                            |      create_con_cq_qp(con); << con[0] > >>>                                            |  } > >>>                                            | in this moment, refcnt of PD was increased to 2+ > >>>                                            | > >>>    create_cm() // b. cid = 1, failed       | > >>>      destroy_con_cq_qp()                   | > >>>        rtrs_ib_dev_put()                   | > >>>          dev_free()                        | > >>>            ib_dealloc_pd(dev->ib_pd) << PD | > >>>             is destroyed, but refcnt is    | > >>>             still greater than 0           | > >>> } > >>> > >>> Simply, Here we can avoid this warning by introducing conn own flag to > >>> track if its cleanup should drop the PD. > >>> > >>> ----------------------------------------------- > >>>   rnbd_client L597: Mapping device /dev/nvme0n1 on session client, (access_mode: rw, nr_poll_queues: 0) > >>>   ------------[ cut here ]------------ > >>>   WARNING: CPU: 0 PID: 26407 at drivers/infiniband/sw/rxe/rxe_pool.c:256 __rxe_cleanup+0x13a/0x170 [rdma_rxe] > >>>   Modules linked in: rpcrdma rdma_ucm ib_iser rnbd_client libiscsi rtrs_client scsi_transport_iscsi rtrs_core rdma_cm iw_cm ib_cm crc32_generic rdma_rxe udp_tunnel ib_uverbs ib_core kmem device_dax nd_pmem dax_pmem nd_ > >>> vme crc32c_intel fuse nvme_core nfit libnvdimm dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua dm_mirror dm_region_hash dm_log dm_mod > >>>   CPU: 0 PID: 26407 Comm: rnbd-client.sh Kdump: loaded Not tainted 6.2.0-rc6-roce-flush+ #53 > >>>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > >>>   RIP: 0010:__rxe_cleanup+0x13a/0x170 [rdma_rxe] > >>>   Code: 45 84 e4 0f 84 5a ff ff ff 48 89 ef e8 5f 18 71 f9 84 c0 75 90 be c8 00 00 00 48 89 ef e8 be 89 1f fa 85 c0 0f 85 7b ff ff ff <0f> 0b 41 bc ea ff ff ff e9 71 ff ff ff e8 84 7f 1f fa e9 d0 fe ff > >>>   RSP: 0018:ffffb09880b6f5f0 EFLAGS: 00010246 > >>>   RAX: 0000000000000000 RBX: ffff99401f15d6a8 RCX: 0000000000000000 > >>>   RDX: 0000000000000001 RSI: ffffffffbac8234b RDI: 00000000ffffffff > >>>   RBP: ffff99401f15d6d0 R08: 0000000000000001 R09: 0000000000000001 > >>>   R10: 0000000000002d82 R11: 0000000000000000 R12: 0000000000000001 > >>>   R13: ffff994101eff208 R14: ffffb09880b6f6a0 R15: 00000000fffffe00 > >>>   FS:  00007fe113904740(0000) GS:ffff99413bc00000(0000) knlGS:0000000000000000 > >>>   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >>>   CR2: 00007ff6cde656c8 CR3: 000000001f108004 CR4: 00000000001706f0 > >>>   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >>>   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >>>   Call Trace: > >>>    > >>>    rxe_dealloc_pd+0x16/0x20 [rdma_rxe] > >>>    ib_dealloc_pd_user+0x4b/0x80 [ib_core] > >>>    rtrs_ib_dev_put+0x79/0xd0 [rtrs_core] > >>>    destroy_con_cq_qp+0x8a/0xa0 [rtrs_client] > >>>    init_path+0x1e7/0x9a0 [rtrs_client] > >>>    ? __pfx_autoremove_wake_function+0x10/0x10 > >>>    ? lock_is_held_type+0xd7/0x130 > >>>    ? rcu_read_lock_sched_held+0x43/0x80 > >>>    ? pcpu_alloc+0x3dd/0x7d0 > >>>    ? rtrs_clt_init_stats+0x18/0x40 [rtrs_client] > >>>    rtrs_clt_open+0x24f/0x5a0 [rtrs_client] > >>>    ? __pfx_rnbd_clt_link_ev+0x10/0x10 [rnbd_client] > >>>    rnbd_clt_map_device+0x6a5/0xe10 [rnbd_client] > >>> > >>> Signed-off-by: Li Zhijian > >>> --- > >>>   drivers/infiniband/ulp/rtrs/rtrs-clt.c | 4 ++++ > >>>   drivers/infiniband/ulp/rtrs/rtrs-clt.h | 1 + > >>>   2 files changed, 5 insertions(+) > >>> > >>> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c > >>> index c2065fc33a56..4c8f42e46e2f 100644 > >>> --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c > >>> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c > >>> @@ -1664,6 +1664,7 @@ static int create_con_cq_qp(struct rtrs_clt_con *con) > >>>               return -ENOMEM; > >>>           } > >>>           clt_path->s.dev_ref = 1; > >>> +        con->has_dev = true; > >>>           query_fast_reg_mode(clt_path); > >>>           wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; > >>>           /* > >>> @@ -1690,6 +1691,7 @@ static int create_con_cq_qp(struct rtrs_clt_con *con) > >>>           wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; > >>>           /* Shared between connections */ > >>>           clt_path->s.dev_ref++; > >> Without looking in the code, I would expect dev_ref from the line above > >> to perform PD protection. > > > > Agreed. > > Sorry, i didn't get your point. Do you mean something like this: > > + con->has_dev = true; > clt_path->s.dev_ref++; No, my point was that clt_path->s.dev_ref > 0 means that has_dev is equal to true, and dev_ref is supposed to protect from early PD destruction. Thanks > > > > Thanks > Zhijian > > > > > Thanks, > > Guoqing