From f2088267514b39af1a94409168101527769a911c Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 16 Jun 2011 11:26:12 -0700 Subject: [PATCH] isci: kill isci_remote_device_change_state() Now that "stopping/stopped" are one in the same and signalled by a NULL device pointer the rest of the device status infrastructure can be removed (->status and ->state_lock). The "not ready for i/o state" is replaced with a state flag, and is evaluated under scic_lock so that we don't see transients from taking the device reference to submitting the i/o. This also fixes a potential leakage of can_queue slots in the rare case that SAS_TASK_ABORTED is set at submission. Signed-off-by: Dan Williams --- drivers/scsi/isci/host.c | 1 - drivers/scsi/isci/remote_device.c | 50 +++------------------------- drivers/scsi/isci/remote_device.h | 5 +-- drivers/scsi/isci/task.c | 68 +++++++++++++-------------------------- 4 files changed, 27 insertions(+), 97 deletions(-) diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c index 40f35fa..b08455f 100644 --- a/drivers/scsi/isci/host.c +++ b/drivers/scsi/isci/host.c @@ -2504,7 +2504,6 @@ int isci_host_init(struct isci_host *isci_host) INIT_LIST_HEAD(&idev->reqs_in_process); INIT_LIST_HEAD(&idev->node); - spin_lock_init(&idev->state_lock); } return 0; diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c index ab5f986..c2e5c05 100644 --- a/drivers/scsi/isci/remote_device.c +++ b/drivers/scsi/isci/remote_device.c @@ -62,24 +62,6 @@ #include "task.h" /** - * isci_remote_device_change_state() - This function gets the status of the - * remote_device object. - * @isci_device: This parameter points to the isci_remote_device object - * - * status of the object as a isci_status enum. - */ -void isci_remote_device_change_state( - struct isci_remote_device *isci_device, - enum isci_status status) -{ - unsigned long flags; - - spin_lock_irqsave(&isci_device->state_lock, flags); - isci_device->status = status; - spin_unlock_irqrestore(&isci_device->state_lock, flags); -} - -/** * isci_remote_device_not_ready() - This function is called by the scic when * the remote device is not ready. We mark the isci device as ready (not * "ready_for_io") and signal the waiting proccess. @@ -96,8 +78,7 @@ static void isci_remote_device_not_ready(struct isci_host *ihost, if (reason == SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED) set_bit(IDEV_GONE, &idev->flags); else - /* device ready is actually a "not ready for io" state. */ - isci_remote_device_change_state(idev, isci_ready); + clear_bit(IDEV_IO_READY, &idev->flags); } /** @@ -113,7 +94,7 @@ static void isci_remote_device_ready(struct isci_host *ihost, struct isci_remote dev_dbg(&ihost->pdev->dev, "%s: idev = %p\n", __func__, idev); - isci_remote_device_change_state(idev, isci_ready_for_io); + set_bit(IDEV_IO_READY, &idev->flags); if (test_and_clear_bit(IDEV_START_PENDING, &idev->flags)) wake_up(&ihost->eventq); } @@ -871,26 +852,6 @@ static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_ isci_put_device(idev); } -/** - * isci_remote_device_stop_complete() - This function is called by the scic - * when the remote device stop has completed. We mark the isci device as not - * ready and remove the isci remote device. - * @ihost: This parameter specifies the isci host object. - * @idev: This parameter specifies the remote device. - * @status: This parameter specifies status of the completion. - * - */ -static void isci_remote_device_stop_complete(struct isci_host *ihost, - struct isci_remote_device *idev) -{ - dev_dbg(&ihost->pdev->dev, "%s: complete idev = %p\n", __func__, idev); - - isci_remote_device_change_state(idev, isci_stopped); - - /* after stop, we can tear down resources. */ - isci_remote_device_deconstruct(ihost, idev); -} - static void scic_sds_remote_device_stopped_state_enter(struct sci_base_state_machine *sm) { struct scic_sds_remote_device *sci_dev = container_of(sm, typeof(*sci_dev), sm); @@ -903,7 +864,7 @@ static void scic_sds_remote_device_stopped_state_enter(struct sci_base_state_mac */ prev_state = sci_dev->sm.previous_state_id; if (prev_state == SCI_DEV_STOPPING) - isci_remote_device_stop_complete(scic_to_ihost(scic), idev); + isci_remote_device_deconstruct(scic_to_ihost(scic), idev); scic_sds_controller_remote_device_stopped(scic, sci_dev); } @@ -1301,8 +1262,6 @@ isci_remote_device_alloc(struct isci_host *ihost, struct isci_port *iport) if (WARN_ONCE(!list_empty(&idev->node), "found non-idle remote device\n")) return NULL; - isci_remote_device_change_state(idev, isci_freed); - return idev; } @@ -1315,6 +1274,7 @@ void isci_remote_device_release(struct kref *kref) idev->isci_port = NULL; clear_bit(IDEV_START_PENDING, &idev->flags); clear_bit(IDEV_STOP_PENDING, &idev->flags); + clear_bit(IDEV_IO_READY, &idev->flags); clear_bit(IDEV_GONE, &idev->flags); clear_bit(IDEV_EH, &idev->flags); smp_mb__before_clear_bit(); @@ -1341,7 +1301,6 @@ enum sci_status isci_remote_device_stop(struct isci_host *ihost, struct isci_rem spin_lock_irqsave(&ihost->scic_lock, flags); idev->domain_dev->lldd_dev = NULL; /* disable new lookups */ set_bit(IDEV_GONE, &idev->flags); - isci_remote_device_change_state(idev, isci_stopping); spin_unlock_irqrestore(&ihost->scic_lock, flags); /* Kill all outstanding requests. */ @@ -1430,7 +1389,6 @@ int isci_remote_device_found(struct domain_device *domain_dev) spin_lock_irq(&isci_host->scic_lock); isci_device->domain_dev = domain_dev; isci_device->isci_port = isci_port; - isci_remote_device_change_state(isci_device, isci_starting); list_add_tail(&isci_device->node, &isci_port->remote_dev_list); set_bit(IDEV_START_PENDING, &isci_device->flags); diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h index 05842b5..33f0114 100644 --- a/drivers/scsi/isci/remote_device.h +++ b/drivers/scsi/isci/remote_device.h @@ -130,19 +130,18 @@ struct scic_sds_remote_device { }; struct isci_remote_device { - enum isci_status status; #define IDEV_START_PENDING 0 #define IDEV_STOP_PENDING 1 #define IDEV_ALLOCATED 2 #define IDEV_EH 3 #define IDEV_GONE 4 + #define IDEV_IO_READY 5 unsigned long flags; struct kref kref; struct isci_port *isci_port; struct domain_device *domain_dev; struct list_head node; struct list_head reqs_in_process; - spinlock_t state_lock; struct scic_sds_remote_device sci; }; @@ -178,8 +177,6 @@ bool isci_device_is_reset_pending(struct isci_host *ihost, struct isci_remote_device *idev); void isci_device_clear_reset_pending(struct isci_host *ihost, struct isci_remote_device *idev); -void isci_remote_device_change_state(struct isci_remote_device *idev, - enum isci_status status); /** * scic_remote_device_stop() - This method will stop both transmission and * reception of link activity for the supplied remote device. This method diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c index dd5e9de..c313bc1 100644 --- a/drivers/scsi/isci/task.c +++ b/drivers/scsi/isci/task.c @@ -147,10 +147,10 @@ int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags) { struct isci_host *ihost = dev_to_ihost(task->dev); struct isci_remote_device *idev; + enum sci_status status; unsigned long flags; + bool io_ready; int ret; - enum sci_status status; - enum isci_status device_status; dev_dbg(&ihost->pdev->dev, "%s: num=%d\n", __func__, num); @@ -163,64 +163,40 @@ int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags) } for_each_sas_task(num, task) { - dev_dbg(&ihost->pdev->dev, - "task = %p, num = %d; dev = %p; cmd = %p\n", - task, num, task->dev, task->uldd_task); spin_lock_irqsave(&ihost->scic_lock, flags); idev = isci_lookup_device(task->dev); + io_ready = idev ? test_bit(IDEV_IO_READY, &idev->flags) : 0; spin_unlock_irqrestore(&ihost->scic_lock, flags); - if (idev) - device_status = idev->status; - else - device_status = isci_freed; - - /* From this point onward, any process that needs to guarantee - * that there is no kernel I/O being started will have to wait - * for the quiesce spinlock. - */ - - if (device_status != isci_ready_for_io) { + dev_dbg(&ihost->pdev->dev, + "task: %p, num: %d dev: %p idev: %p:%#lx cmd = %p\n", + task, num, task->dev, idev, idev ? idev->flags : 0, + task->uldd_task); - /* Forces a retry from scsi mid layer. */ - dev_dbg(&ihost->pdev->dev, - "%s: task %p: isci_host->status = %d, " - "device = %p; device_status = 0x%x\n\n", - __func__, - task, - isci_host_get_state(ihost), - idev, - device_status); - - if (device_status == isci_ready) { - /* Indicate QUEUE_FULL so that the scsi midlayer - * retries. - */ - isci_task_refuse(ihost, task, - SAS_TASK_COMPLETE, - SAS_QUEUE_FULL); - } else { - /* Else, the device is going down. */ - isci_task_refuse(ihost, task, - SAS_TASK_UNDELIVERED, - SAS_DEVICE_UNKNOWN); - } + if (!idev) { + isci_task_refuse(ihost, task, SAS_TASK_UNDELIVERED, + SAS_DEVICE_UNKNOWN); + isci_host_can_dequeue(ihost, 1); + } else if (!io_ready) { + /* Indicate QUEUE_FULL so that the scsi midlayer + * retries. + */ + isci_task_refuse(ihost, task, SAS_TASK_COMPLETE, + SAS_QUEUE_FULL); isci_host_can_dequeue(ihost, 1); } else { /* There is a device and it's ready for I/O. */ spin_lock_irqsave(&task->task_state_lock, flags); if (task->task_state_flags & SAS_TASK_STATE_ABORTED) { - + /* The I/O was aborted. */ spin_unlock_irqrestore(&task->task_state_lock, flags); isci_task_refuse(ihost, task, SAS_TASK_UNDELIVERED, SAM_STAT_TASK_ABORTED); - - /* The I/O was aborted. */ - + isci_host_can_dequeue(ihost, 1); } else { task->task_state_flags |= SAS_TASK_AT_INITIATOR; spin_unlock_irqrestore(&task->task_state_lock, flags); @@ -323,11 +299,11 @@ int isci_task_execute_tmf(struct isci_host *ihost, /* sanity check, return TMF_RESP_FUNC_FAILED * if the device is not there and ready. */ - if (!isci_device || isci_device->status != isci_ready_for_io) { + if (!isci_device || !test_bit(IDEV_IO_READY, &isci_device->flags)) { dev_dbg(&ihost->pdev->dev, - "%s: isci_device = %p not ready (%d)\n", + "%s: isci_device = %p not ready (%#lx)\n", __func__, - isci_device, isci_device->status); + isci_device, isci_device ? isci_device->flags : 0); return TMF_RESP_FUNC_FAILED; } else dev_dbg(&ihost->pdev->dev, -- 2.7.4