From patchwork Fri Dec 6 01:11:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11275529 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7FB6614BD for ; Fri, 6 Dec 2019 01:11:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CFA624659 for ; Fri, 6 Dec 2019 01:11:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726171AbfLFBL4 (ORCPT ); Thu, 5 Dec 2019 20:11:56 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:58990 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725959AbfLFBL4 (ORCPT ); Thu, 5 Dec 2019 20:11:56 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 858105EC6FBED0EC5558; Fri, 6 Dec 2019 09:11:53 +0800 (CST) Received: from huawei.com (10.175.124.28) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Fri, 6 Dec 2019 09:11:44 +0800 From: Jason Yan To: , CC: , , Jason Yan Subject: [PATCH v3] scsi: libsas: stop discovering if oob mode is disconnected Date: Fri, 6 Dec 2019 09:11:18 +0800 Message-ID: <20191206011118.46909-1-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The discovering of sas port is driven by workqueue in libsas. When libsas is processing port events or phy events in workqueue, new events may rise up and change the state of some structures such as asd_sas_phy. This may cause some problems such as follows: ==>thread 1 ==>thread 2 ==>phy up ==>phy_up_v3_hw() ==>oob_mode = SATA_OOB_MODE; ==>phy down quickly ==>hisi_sas_phy_down() ==>sas_ha->notify_phy_event() ==>sas_phy_disconnected() ==>oob_mode = OOB_NOT_CONNECTED ==>workqueue wakeup ==>sas_form_port() ==>sas_discover_domain() ==>sas_get_port_device() ==>oob_mode is OOB_NOT_CONNECTED and device is wrongly taken as expander This at last lead to the panic when libsas trying to issue a command to discover the device. [183047.614035] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [183047.622896] Mem abort info: [183047.625762] ESR = 0x96000004 [183047.628893] Exception class = DABT (current EL), IL = 32 bits [183047.634888] SET = 0, FnV = 0 [183047.638015] EA = 0, S1PTW = 0 [183047.641232] Data abort info: [183047.644189] ISV = 0, ISS = 0x00000004 [183047.648100] CM = 0, WnR = 0 [183047.651145] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000b7df67be [183047.657834] [0000000000000058] pgd=0000000000000000 [183047.662789] Internal error: Oops: 96000004 [#1] SMP [183047.667740] Process kworker/u16:2 (pid: 31291, stack limit = 0x00000000417c4974) [183047.675208] CPU: 0 PID: 3291 Comm: kworker/u16:2 Tainted: G W OE 4.19.36-vhulk1907.1.0.h410.eulerosv2r8.aarch64 #1 [183047.687015] Hardware name: N/A N/A/Kunpeng Desktop Board D920S10, BIOS 0.15 10/22/2019 [183047.695007] Workqueue: 0000:74:02.0_disco_q sas_discover_domain [183047.700999] pstate: 20c00009 (nzCv daif +PAN +UAO) [183047.705864] pc : prep_ata_v3_hw+0xf8/0x230 [hisi_sas_v3_hw] [183047.711510] lr : prep_ata_v3_hw+0xb0/0x230 [hisi_sas_v3_hw] [183047.717153] sp : ffff00000f28ba60 [183047.720541] x29: ffff00000f28ba60 x28: ffff8026852d7228 [183047.725925] x27: ffff8027dba3e0a8 x26: ffff8027c05fc200 [183047.731310] x25: 0000000000000000 x24: ffff8026bafa8dc0 [183047.736695] x23: ffff8027c05fc218 x22: ffff8026852d7228 [183047.742079] x21: ffff80007c2f2940 x20: ffff8027c05fc200 [183047.747464] x19: 0000000000f80800 x18: 0000000000000010 [183047.752848] x17: 0000000000000000 x16: 0000000000000000 [183047.758232] x15: ffff000089a5a4ff x14: 0000000000000005 [183047.763617] x13: ffff000009a5a50e x12: ffff8026bafa1e20 [183047.769001] x11: ffff0000087453b8 x10: ffff00000f28b870 [183047.774385] x9 : 0000000000000000 x8 : ffff80007e58f9b0 [183047.779770] x7 : 0000000000000000 x6 : 000000000000003f [183047.785154] x5 : 0000000000000040 x4 : ffffffffffffffe0 [183047.790538] x3 : 00000000000000f8 x2 : 0000000002000007 [183047.795922] x1 : 0000000000000008 x0 : 0000000000000000 [183047.801307] Call trace: [183047.803827] prep_ata_v3_hw+0xf8/0x230 [hisi_sas_v3_hw] [183047.809127] hisi_sas_task_prep+0x750/0x888 [hisi_sas_main] [183047.814773] hisi_sas_task_exec.isra.7+0x88/0x1f0 [hisi_sas_main] [183047.820939] hisi_sas_queue_command+0x28/0x38 [hisi_sas_main] [183047.826757] smp_execute_task_sg+0xec/0x218 [183047.831013] smp_execute_task+0x74/0xa0 [183047.834921] sas_discover_expander.part.7+0x9c/0x5f8 [183047.839959] sas_discover_root_expander+0x90/0x160 [183047.844822] sas_discover_domain+0x1b8/0x1e8 [183047.849164] process_one_work+0x1b4/0x3f8 [183047.853246] worker_thread+0x54/0x470 [183047.856981] kthread+0x134/0x138 [183047.860283] ret_from_fork+0x10/0x18 [183047.863931] Code: f9407a80 528000e2 39409281 72a04002 (b9405800) [183047.870097] kernel fault(0x1) notification starting on CPU 0 [183047.875828] kernel fault(0x1) notification finished on CPU 0 [183047.881559] Modules linked in: unibsp(OE) hns3(OE) hclge(OE) hnae3(OE) mem_drv(OE) hisi_sas_v3_hw(OE) hisi_sas_main(OE) [183047.892418] ---[ end trace 4cc26083fc11b783 ]--- [183047.897107] Kernel panic - not syncing: Fatal exception [183047.902403] kernel fault(0x5) notification starting on CPU 0 [183047.908134] kernel fault(0x5) notification finished on CPU 0 [183047.913865] SMP: stopping secondary CPUs [183047.917861] Kernel Offset: disabled [183047.921422] CPU features: 0x2,a2a00a38 [183047.925243] Memory Limit: none [183047.928372] kernel reboot(0x2) notification starting on CPU 0 [183047.934190] kernel reboot(0x2) notification finished on CPU 0 [183047.940008] ---[ end Kernel panic - not syncing: Fatal exception ]--- Fixes: 2908d778ab3e ("[SCSI] aic94xx: new driver") Reported-by: Gao Chuan Signed-off-by: Jason Yan Reviewed-by: John Garry --- drivers/scsi/libsas/sas_discover.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c index f47b4b281b14..d7302c2052f9 100644 --- a/drivers/scsi/libsas/sas_discover.c +++ b/drivers/scsi/libsas/sas_discover.c @@ -81,12 +81,21 @@ static int sas_get_port_device(struct asd_sas_port *port) else dev->dev_type = SAS_SATA_DEV; dev->tproto = SAS_PROTOCOL_SATA; - } else { + } else if (port->oob_mode == SAS_OOB_MODE) { struct sas_identify_frame *id = (struct sas_identify_frame *) dev->frame_rcvd; dev->dev_type = id->dev_type; dev->iproto = id->initiator_bits; dev->tproto = id->target_bits; + } else { + /* If the oob mode is OOB_NOT_CONNECTED, the port is + * disconnected due to race with PHY down. We cannot + * continue to discover this port + */ + sas_put_device(dev); + pr_warn("Port %016llx is disconnected when discovering\n", + SAS_ADDR(port->attached_sas_addr)); + return -ENODEV; } sas_init_dev(dev);