From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Lawrence Subject: [PATCH 5/6] qla2xxx: Prevent removal and board_disable race Date: Wed, 18 Jun 2014 10:04:43 -0400 Message-ID: <1403100284-1872-1-git-send-email-joe.lawrence@stratus.com> References: <1403100139-1798-1-git-send-email-joe.lawrence@stratus.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from p01c11o142.mxlogic.net ([208.65.144.65]:57724 "EHLO p01c11o142.mxlogic.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751792AbaFROF0 (ORCPT ); Wed, 18 Jun 2014 10:05:26 -0400 In-Reply-To: <1403100139-1798-1-git-send-email-joe.lawrence@stratus.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: Chad Dupuis , Giridhar Malavali , Saurav Kashyap , Don Zickus , Prarit Bhargava , Bill Kuzeja , Dave Bulkow , Joe Lawrence Introduce mutual exclusion between the qla2xxx_remove_one PCI driver callback and qla2x00_disable_board_on_pci_error, which is scheduled as board_disable work by qla2x00_check_reg{32,16}_for_disconnect: * Leave the driver-specific data attached to the underlying PCI device intact in qla2x00_disable_board_on_pci_error, so that qla2x00_remove_one has enough breadcrumbs to determine that any board_disable work has been completed. * In qla2xxx_remove_one, set a bit to prevent any subsequent board_disable work from scheduling, then cancel and wait until pending work has completed. * Reuse the PCI device enable count check in qla2x00_remove_one to determine if board_disable has occured. The original purpose of this check was unnecessary since the driver remove function wasn't called when the probe fails. Signed-off-by: Joe Lawrence --- drivers/scsi/qla2xxx/qla_def.h | 1 + drivers/scsi/qla2xxx/qla_isr.c | 3 ++- drivers/scsi/qla2xxx/qla_os.c | 31 +++++++++++++++++++------------ 3 files changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h index 1267b11..7c441c9 100644 --- a/drivers/scsi/qla2xxx/qla_def.h +++ b/drivers/scsi/qla2xxx/qla_def.h @@ -3404,6 +3404,7 @@ typedef struct scsi_qla_host { unsigned long pci_flags; #define PFLG_DISCONNECTED 0 /* PCI device removed */ +#define PFLG_DRIVER_REMOVING 1 /* PCI driver .remove */ uint32_t device_flags; #define SWITCH_FOUND BIT_0 diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c index 2741ad8..ee5eef4 100644 --- a/drivers/scsi/qla2xxx/qla_isr.c +++ b/drivers/scsi/qla2xxx/qla_isr.c @@ -117,7 +117,8 @@ qla2x00_check_reg32_for_disconnect(scsi_qla_host_t *vha, uint32_t reg) { /* Check for PCI disconnection */ if (reg == 0xffffffff) { - if (!test_and_set_bit(PFLG_DISCONNECTED, &vha->pci_flags)) { + if (!test_and_set_bit(PFLG_DISCONNECTED, &vha->pci_flags) && + !test_bit(PFLG_DRIVER_REMOVING, &vha->pci_flags)) { /* * Schedule this (only once) on the default system * workqueue so that all the adapter workqueues and the diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 39c9953..51cba37 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -3123,15 +3123,25 @@ qla2x00_remove_one(struct pci_dev *pdev) scsi_qla_host_t *base_vha; struct qla_hw_data *ha; + base_vha = pci_get_drvdata(pdev); + ha = base_vha->hw; + + /* Indicate device removal to prevent future board_disable and wait + * until any pending board_disable has completed. */ + set_bit(PFLG_DRIVER_REMOVING, &base_vha->pci_flags); + cancel_work_sync(&ha->board_disable); + /* - * If the PCI device is disabled that means that probe failed and any - * resources should be have cleaned up on probe exit. + * If the PCI device is disabled then there was a PCI-disconnect and + * qla2x00_disable_board_on_pci_error has taken care of most of the + * resources. */ - if (!atomic_read(&pdev->enable_cnt)) + if (!atomic_read(&pdev->enable_cnt)) { + scsi_host_put(base_vha->host); + kfree(ha); + pci_set_drvdata(pdev, NULL); return; - - base_vha = pci_get_drvdata(pdev); - ha = base_vha->hw; + } qla2x00_wait_for_hba_ready(base_vha); @@ -4791,18 +4801,15 @@ qla2x00_disable_board_on_pci_error(struct work_struct *work) qla82xx_md_free(base_vha); qla2x00_free_queues(ha); - scsi_host_put(base_vha->host); - qla2x00_unmap_iobases(ha); pci_release_selected_regions(ha->pdev, ha->bars); - kfree(ha); - ha = NULL; - pci_disable_pcie_error_reporting(pdev); pci_disable_device(pdev); - pci_set_drvdata(pdev, NULL); + /* + * Let qla2x00_remove_one cleanup qla_hw_data on device removal. + */ } /************************************************************************** -- 1.7.10.4