From 217ee6c64a9589bc5ad4d1c88136fc359d17930b Mon Sep 17 00:00:00 2001 From: Michael Ernst Date: Fri, 11 Sep 2009 10:28:21 +0200 Subject: [PATCH] [S390] cio: failing set online/offline processing. When unit checks trigger sensing the device state is set to W4SENSE until sense completion; then the device state is set back to ONLINE. If a unit check occurs while set online or set offline requests are processed then it might happen that the device's temporary W4SENSE state causes these functions to terminate, leaving the device in an inconsistent state when the state is set back to ONLINE later on so that the device cannot be set online or offline any longer. To solve this, set online/offline and related rollback or error routines are processed only if the device is in a final or DISCONNECTED state. Signed-off-by: Michael Ernst Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device.c | 100 +++++++++++++++++++++++++++--------------- drivers/s390/cio/device_fsm.c | 2 + 2 files changed, 67 insertions(+), 35 deletions(-) diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index a7a340b..a50cfa5 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -380,30 +380,34 @@ int ccw_device_set_offline(struct ccw_device *cdev) } cdev->online = 0; spin_lock_irq(cdev->ccwlock); - ret = ccw_device_offline(cdev); - if (ret == -ENODEV) { - if (cdev->private->state != DEV_STATE_NOT_OPER) { - cdev->private->state = DEV_STATE_OFFLINE; - dev_fsm_event(cdev, DEV_EVENT_NOTOPER); - } + /* Wait until a final state or DISCONNECTED is reached */ + while (!dev_fsm_final_state(cdev) && + cdev->private->state != DEV_STATE_DISCONNECTED) { spin_unlock_irq(cdev->ccwlock); - /* Give up reference from ccw_device_set_online(). */ - put_device(&cdev->dev); - return ret; + wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) || + cdev->private->state == DEV_STATE_DISCONNECTED)); + spin_lock_irq(cdev->ccwlock); } + ret = ccw_device_offline(cdev); + if (ret) + goto error; spin_unlock_irq(cdev->ccwlock); - if (ret == 0) { - wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev)); - /* Give up reference from ccw_device_set_online(). */ - put_device(&cdev->dev); - } else { - CIO_MSG_EVENT(0, "ccw_device_offline returned %d, " - "device 0.%x.%04x\n", - ret, cdev->private->dev_id.ssid, - cdev->private->dev_id.devno); - cdev->online = 1; - } - return ret; + wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) || + cdev->private->state == DEV_STATE_DISCONNECTED)); + /* Give up reference from ccw_device_set_online(). */ + put_device(&cdev->dev); + return 0; + +error: + CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device 0.%x.%04x\n", + ret, cdev->private->dev_id.ssid, + cdev->private->dev_id.devno); + cdev->private->state = DEV_STATE_OFFLINE; + dev_fsm_event(cdev, DEV_EVENT_NOTOPER); + spin_unlock_irq(cdev->ccwlock); + /* Give up reference from ccw_device_set_online(). */ + put_device(&cdev->dev); + return -ENODEV; } /** @@ -421,6 +425,7 @@ int ccw_device_set_offline(struct ccw_device *cdev) int ccw_device_set_online(struct ccw_device *cdev) { int ret; + int ret2; if (!cdev) return -ENODEV; @@ -444,28 +449,53 @@ int ccw_device_set_online(struct ccw_device *cdev) put_device(&cdev->dev); return ret; } - if (cdev->private->state != DEV_STATE_ONLINE) { + spin_lock_irq(cdev->ccwlock); + /* Check if online processing was successful */ + if ((cdev->private->state != DEV_STATE_ONLINE) && + (cdev->private->state != DEV_STATE_W4SENSE)) { + spin_unlock_irq(cdev->ccwlock); /* Give up online reference since onlining failed. */ put_device(&cdev->dev); return -ENODEV; } - if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) { - cdev->online = 1; - return 0; - } + spin_unlock_irq(cdev->ccwlock); + if (cdev->drv->set_online) + ret = cdev->drv->set_online(cdev); + if (ret) + goto rollback; + cdev->online = 1; + return 0; + +rollback: spin_lock_irq(cdev->ccwlock); - ret = ccw_device_offline(cdev); + /* Wait until a final state or DISCONNECTED is reached */ + while (!dev_fsm_final_state(cdev) && + cdev->private->state != DEV_STATE_DISCONNECTED) { + spin_unlock_irq(cdev->ccwlock); + wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) || + cdev->private->state == DEV_STATE_DISCONNECTED)); + spin_lock_irq(cdev->ccwlock); + } + ret2 = ccw_device_offline(cdev); + if (ret2) + goto error; spin_unlock_irq(cdev->ccwlock); - if (ret == 0) - wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev)); - else - CIO_MSG_EVENT(0, "ccw_device_offline returned %d, " - "device 0.%x.%04x\n", - ret, cdev->private->dev_id.ssid, - cdev->private->dev_id.devno); + wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) || + cdev->private->state == DEV_STATE_DISCONNECTED)); /* Give up online reference since onlining failed. */ put_device(&cdev->dev); - return (ret == 0) ? -ENODEV : ret; + return ret; + +error: + CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, " + "device 0.%x.%04x\n", + ret2, cdev->private->dev_id.ssid, + cdev->private->dev_id.devno); + cdev->private->state = DEV_STATE_OFFLINE; + spin_unlock_irq(cdev->ccwlock); + /* Give up online reference since onlining failed. */ + put_device(&cdev->dev); + return ret; } static int online_store_handle_offline(struct ccw_device *cdev) diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c index 9c1452a..e728ce4 100644 --- a/drivers/s390/cio/device_fsm.c +++ b/drivers/s390/cio/device_fsm.c @@ -905,6 +905,8 @@ ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event) } call_handler: cdev->private->state = DEV_STATE_ONLINE; + /* In case sensing interfered with setting the device online */ + wake_up(&cdev->private->wait_q); /* Call the handler. */ if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify) /* Start delayed path verification. */ -- 2.7.4