From patchwork Tue Dec 19 19:36:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Don Brace X-Patchwork-Id: 13499017 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 183BA39AC6 for ; Tue, 19 Dec 2023 19:37:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=microchip.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=microchip.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="C76dSHFI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1703014642; x=1734550642; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9XlKijK4XuHMN8gDTuZcRf4egvfTs3qhReYoCDGcUuI=; b=C76dSHFI2upDjCnAaeNsNdmIdjw3d6NPKHbzP6zB7e9s+qO02QIm4l4Q LK8hy2aBxki1LeWLYiMXBGYXCkuCAAo4UNhgGeMXol7j5aKbjroTocld1 i6+VNtSRUvn3jsZyBmhFYEp/hwxUAuvJnvk4aEjitsgx+IRIsJeQ8jZFe c7Eyv39G2za2l/49bR/3phyaoz516cQkn6VRgrQsxFJJNuEpZnNYRT8sx Qymnf4x15quAMEIZQ+hu6hdx5w5kJ3f8pPtOWoJuMCzw22K5Ezgx7iSxa 9IsD5VGNRUGN0eCuLuoKFPbM8hmouKKqrviKlF265+DvY8DQSdqIPJokf A==; X-CSE-ConnectionGUID: QfATRU5QQbSZ4OmFfcIKRQ== X-CSE-MsgGUID: Th3VWzNXQ1e8ZGN2MtMemA== X-ThreatScanner-Verdict: Negative X-IronPort-AV: E=Sophos;i="6.04,289,1695711600"; d="scan'208";a="13591433" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa3.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 19 Dec 2023 12:37:18 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Tue, 19 Dec 2023 12:36:55 -0700 Received: from brunhilda.pdev.net (10.10.85.11) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server id 15.1.2507.35 via Frontend Transport; Tue, 19 Dec 2023 12:36:54 -0700 From: Don Brace To: , , , , , , , , , , , , , , , CC: Subject: [PATCH 2/3] smartpqi: fix logical volume rescan race condition Date: Tue, 19 Dec 2023 13:36:51 -0600 Message-ID: <20231219193653.277553-3-don.brace@microchip.com> X-Mailer: git-send-email 2.43.0.76.g1a87c842ec In-Reply-To: <20231219193653.277553-1-don.brace@microchip.com> References: <20231219193653.277553-1-don.brace@microchip.com> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Mahesh Rajashekhara Correct rescan flag race condition. Multiple conditions are being evaluated before notifying OS to do a rescan. Driver will skip re-scanning the device if any one of the following conditions are met: - Devices that have not yet been added to the OS or devices that have been removed. - Devices which are already marked for removal or in the phase of removal. Under very rare conditions, after logical volume size expansion, the OS still sees the size of the logical volume which was before expansion. The rescan flag in the driver is used to signal the need for a logical volume rescan. A race condition can occur in the driver, and it leads to one thread overwriting the flag inadvertently. As a result, driver is not notifying the OS SML to rescan the logical volume. Move device->rescan update into new function pqi_mark_volumes_for_rescan() and protect with a spin lock. Move check for device->rescan into new function pqi_volume_rescan_needed() and protect function call with a spin_lock. Reviewed-by: Scott Teel Reviewed-by: Scott Benesh Reviewed-by: Mike McGowen Reviewed-by: Kevin Barnett Co-developed-by: Murthy Bhat Signed-off-by: Murthy Bhat Signed-off-by: Mahesh Rajashekhara Signed-off-by: Don Brace --- drivers/scsi/smartpqi/smartpqi.h | 1 - drivers/scsi/smartpqi/smartpqi_init.c | 43 ++++++++++++++++++++++----- 2 files changed, 36 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index 041940183516..cdedc271857a 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -1347,7 +1347,6 @@ struct pqi_ctrl_info { bool controller_online; bool block_requests; bool scan_blocked; - u8 logical_volume_rescan_needed : 1; u8 inbound_spanning_supported : 1; u8 outbound_spanning_supported : 1; u8 pqi_mode_enabled : 1; diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index d56201120087..081bb2c09806 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -2093,8 +2093,6 @@ static void pqi_scsi_update_device(struct pqi_ctrl_info *ctrl_info, if (existing_device->devtype == TYPE_DISK) { existing_device->raid_level = new_device->raid_level; existing_device->volume_status = new_device->volume_status; - if (ctrl_info->logical_volume_rescan_needed) - existing_device->rescan = true; memset(existing_device->next_bypass_group, 0, sizeof(existing_device->next_bypass_group)); if (!pqi_raid_maps_equal(existing_device->raid_map, new_device->raid_map)) { kfree(existing_device->raid_map); @@ -2164,6 +2162,20 @@ static inline void pqi_init_device_tmf_work(struct pqi_scsi_dev *device) INIT_WORK(&tmf_work->work_struct, pqi_tmf_worker); } +static inline bool pqi_volume_rescan_needed(struct pqi_scsi_dev *device) +{ + if (pqi_device_in_remove(device)) + return false; + + if (device->sdev == NULL) + return false; + + if (!scsi_device_online(device->sdev)) + return false; + + return device->rescan; +} + static void pqi_update_device_list(struct pqi_ctrl_info *ctrl_info, struct pqi_scsi_dev *new_device_list[], unsigned int num_new_devices) { @@ -2284,9 +2296,13 @@ static void pqi_update_device_list(struct pqi_ctrl_info *ctrl_info, if (device->sdev && device->queue_depth != device->advertised_queue_depth) { device->advertised_queue_depth = device->queue_depth; scsi_change_queue_depth(device->sdev, device->advertised_queue_depth); - if (device->rescan) { - scsi_rescan_device(device->sdev); + spin_lock_irqsave(&ctrl_info->scsi_device_list_lock, flags); + if (pqi_volume_rescan_needed(device)) { device->rescan = false; + spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags); + scsi_rescan_device(device->sdev); + } else { + spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags); } } } @@ -2308,8 +2324,6 @@ static void pqi_update_device_list(struct pqi_ctrl_info *ctrl_info, } } - ctrl_info->logical_volume_rescan_needed = false; - } static inline bool pqi_is_supported_device(struct pqi_scsi_dev *device) @@ -3702,6 +3716,21 @@ static bool pqi_ofa_process_event(struct pqi_ctrl_info *ctrl_info, return ack_event; } +static void pqi_mark_volumes_for_rescan(struct pqi_ctrl_info *ctrl_info) +{ + unsigned long flags; + struct pqi_scsi_dev *device; + + spin_lock_irqsave(&ctrl_info->scsi_device_list_lock, flags); + + list_for_each_entry(device, &ctrl_info->scsi_device_list, scsi_device_list_entry) { + if (pqi_is_logical_device(device) && device->devtype == TYPE_DISK) + device->rescan = true; + } + + spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags); +} + static void pqi_disable_raid_bypass(struct pqi_ctrl_info *ctrl_info) { unsigned long flags; @@ -3742,7 +3771,7 @@ static void pqi_event_worker(struct work_struct *work) ack_event = true; rescan_needed = true; if (event->event_type == PQI_EVENT_TYPE_LOGICAL_DEVICE) - ctrl_info->logical_volume_rescan_needed = true; + pqi_mark_volumes_for_rescan(ctrl_info); else if (event->event_type == PQI_EVENT_TYPE_AIO_STATE_CHANGE) pqi_disable_raid_bypass(ctrl_info); }