From patchwork Mon Dec 4 12:29:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: yangxingui X-Patchwork-Id: 13478269 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B639CD2; Mon, 4 Dec 2023 04:32:34 -0800 (PST) Received: from dggpemd100001.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4SkNMK0hhTzWjH6; Mon, 4 Dec 2023 20:31:41 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by dggpemd100001.china.huawei.com (7.185.36.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1258.28; Mon, 4 Dec 2023 20:32:32 +0800 From: Xingui Yang To: , , , , CC: , , , , , Subject: [PATCH v5 3/3] scsi: libsas: Fix the failure of adding phy with zero-address to port Date: Mon, 4 Dec 2023 12:29:32 +0000 Message-ID: <20231204122932.55741-4-yangxingui@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20231204122932.55741-1-yangxingui@huawei.com> References: <20231204122932.55741-1-yangxingui@huawei.com> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemd100001.china.huawei.com (7.185.36.94) X-CFilter-Loop: Reflected When the expander device which attached many SATA disks is connected to the host, first disable and then enable the local phy. The following BUG() will be triggered with a small probability: [562240.051046] sas: phy19 part of wide port with phy16 [562240.051197] sas: ex 500e004aaaaaaa1f phy19:U:0 attached: 0000000000000000 (no device) [562240.051203] sas: done REVALIDATING DOMAIN on port 0, pid:435909, res 0x0 <...> [562240.062536] sas: ex 500e004aaaaaaa1f phy0 new device attached [562240.062616] sas: ex 500e004aaaaaaa1f phy00:U:5 attached: 0000000000000000 (stp) [562240.062680] port-7:7:0: trying to add phy phy-7:7:19 fails: it's already part of another port [562240.085064] ------------[ cut here ]------------ [562240.096612] kernel BUG at drivers/scsi/scsi_transport_sas.c:1083! [562240.109611] Internal error: Oops - BUG: 0 [#1] SMP [562240.343518] Process kworker/u256:3 (pid: 435909, stack limit = 0x0000000003bcbebf) [562240.421714] Workqueue: 0000:b4:02.0_disco_q sas_revalidate_domain [libsas] [562240.437173] pstate: 40c00009 (nZcv daif +PAN +UAO) [562240.450478] pc : sas_port_add_phy+0x13c/0x168 [scsi_transport_sas] [562240.465283] lr : sas_port_add_phy+0x13c/0x168 [scsi_transport_sas] [562240.479751] sp : ffff0000300cfa70 [562240.674822] Call trace: [562240.682709] sas_port_add_phy+0x13c/0x168 [scsi_transport_sas] [562240.694013] sas_ex_get_linkrate.isra.5+0xcc/0x128 [libsas] [562240.704957] sas_ex_discover_end_dev+0xfc/0x538 [libsas] [562240.715508] sas_ex_discover_dev+0x3cc/0x4b8 [libsas] [562240.725634] sas_ex_discover_devices+0x9c/0x1a8 [libsas] [562240.735855] sas_ex_revalidate_domain+0x2f0/0x450 [libsas] [562240.746123] sas_revalidate_domain+0x158/0x160 [libsas] [562240.756014] process_one_work+0x1b4/0x448 [562240.764548] worker_thread+0x54/0x468 [562240.772562] kthread+0x134/0x138 [562240.779989] ret_from_fork+0x10/0x18 What causes this problem: 1. For phy19, when the phy is attached and added to the parent wide port, the path is: sas_rediscover() ->sas_discover_new() ->sas_ex_discover_devices() ->sas_ex_discover_dev() -> sas_add_parent_port() ex_phy->port was not set and when it is removed from parent wide port the path is: sas_rediscover() ->sas_unregister_devs_sas_addr() Then the sas address of phy19 becomes 0, and since ex_phy->port is NULL, phy19 was not removed from the parent wide port's phy_list. 2. For phy0, it is connected to a new sata device and the path is: sas_rediscover() ->sas_discover_new()->sas_ex_phy_discover() ->sas_ex_phy_discover_helper() ->sas_set_ex_phy() ->sas_ex_discover_devices() ->sas_ex_discover_dev() ->sas_ex_discover_end_dev() ->sas_port_alloc() // Create port-7:7:0 ->sas_ex_get_linkrate() ->sas_port_add_phy() The type of the newly connected device is stp, but the linkrate is 5 which less than 1.5G, then the sas address is set to 0 in sas_set_ex_phy(). Subsequently, a new port port-7:7:0 was created and tried to add phy19 with the same zero-address to this new port. However, phy19 still belongs to another port, then a BUG() was triggered in sas_ex_get_linkrate(). Fix the problem as follows: 1. Use sas_port_add_ex_phy() instead of sas_port_add_phy() when ex_phy is added to the parent port. 2. Set ex_dev->parent_port to NULL when the number of phy on the port becomes 0. 3. When phy->attached_dev_type != NO_DEVICE, do not set the zero address for phy->attached_sas_addr. Fixes: 2908d778ab3e ("[SCSI] aic94xx: new driver") Fixes: 7d1d86518118 ("[SCSI] libsas: fix false positive 'device attached' conditions") Signed-off-by: Xingui Yang --- drivers/scsi/libsas/sas_expander.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index 7aa968b85e1e..9152152d5e10 100644 --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -45,7 +45,7 @@ static void sas_add_parent_port(struct domain_device *dev, int phy_id) BUG_ON(sas_port_add(ex->parent_port)); sas_port_mark_backlink(ex->parent_port); } - sas_port_add_phy(ex->parent_port, ex_phy->phy); + sas_port_add_ex_phy(ex->parent_port, ex_phy); } /* ---------- SMP task management ---------- */ @@ -261,8 +261,7 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id, /* help some expanders that fail to zero sas_address in the 'no * device' case */ - if (phy->attached_dev_type == SAS_PHY_UNUSED || - phy->linkrate < SAS_LINK_RATE_1_5_GBPS) + if (phy->attached_dev_type == SAS_PHY_UNUSED) memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE); else memcpy(phy->attached_sas_addr, dr->attached_sas_addr, SAS_ADDR_SIZE); @@ -1864,9 +1863,12 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent, if (phy->port) { sas_port_delete_phy(phy->port, phy->phy); sas_device_set_phy(found, phy->port); - if (phy->port->num_phys == 0) + if (phy->port->num_phys == 0) { list_add_tail(&phy->port->del_list, &parent->port->sas_port_del_list); + if (ex_dev->parent_port == phy->port) + ex_dev->parent_port = NULL; + } phy->port = NULL; } }