From d06b487b78f28a02efdcdcc9ec295bf230b9d0e8 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 2 May 2011 13:59:25 -0700 Subject: [PATCH] isci: implement I_T_nexus_reset This is a requirement for 2.6.39's new libata eh. Still some questions about lldd_dev_gone racing against dev->lldd_dev lookups, but we are at least no more broken than mvsas in this regard. We also short-circuit I_T_nexus_reset invocations from the device discovery path (IDEV_EH similar to MVS_DEV_EH) to filter out the resulting domain rediscoveries triggered by the reset. Signed-off-by: Dan Williams --- drivers/scsi/isci/remote_device.c | 1 + drivers/scsi/isci/remote_device.h | 1 + drivers/scsi/isci/task.c | 138 ++++++++++++++++++++------------------ 3 files changed, 76 insertions(+), 64 deletions(-) diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c index 15c1e6c..ee6fe1d 100644 --- a/drivers/scsi/isci/remote_device.c +++ b/drivers/scsi/isci/remote_device.c @@ -891,6 +891,7 @@ static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_ clear_bit(IDEV_START_PENDING, &idev->flags); clear_bit(IDEV_STOP_PENDING, &idev->flags); + clear_bit(IDEV_EH, &idev->flags); wake_up(&ihost->eventq); } diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h index c7db499..2e433b7 100644 --- a/drivers/scsi/isci/remote_device.h +++ b/drivers/scsi/isci/remote_device.h @@ -134,6 +134,7 @@ struct isci_remote_device { #define IDEV_START_PENDING 0 #define IDEV_STOP_PENDING 1 #define IDEV_ALLOCATED 2 + #define IDEV_EH 3 unsigned long flags; struct isci_port *isci_port; struct domain_device *domain_dev; diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c index 8449d8a..3a3f546 100644 --- a/drivers/scsi/isci/task.c +++ b/drivers/scsi/isci/task.c @@ -1022,9 +1022,11 @@ int isci_task_lu_reset(struct domain_device *domain_device, u8 *lun) "%s: domain_device=%p, isci_host=%p; isci_device=%p\n", __func__, domain_device, isci_host, isci_device); - if (isci_device != NULL) + if (isci_device != NULL) { device_stopping = (isci_device->status == isci_stopping) || (isci_device->status == isci_stopped); + set_bit(IDEV_EH, &isci_device->flags); + } /* If there is a device reset pending on any request in the * device's list, fail this LUN reset request in order to @@ -1069,12 +1071,6 @@ int isci_task_clear_nexus_ha(struct sas_ha_struct *ha) return TMF_RESP_FUNC_FAILED; } -int isci_task_I_T_nexus_reset(struct domain_device *dev) -{ - return TMF_RESP_FUNC_FAILED; -} - - /* Task Management Functions. Must be called from process context. */ /** @@ -1171,6 +1167,12 @@ int isci_task_abort_task(struct sas_task *task) device_stopping = (isci_device->status == isci_stopping) || (isci_device->status == isci_stopped); + /* XXX need to fix device lookup lifetime (needs to be done + * under scic_lock, among other things...), but for now assume + * the device is available like the above code + */ + set_bit(IDEV_EH, &isci_device->flags); + /* This version of the driver will fail abort requests for * SATA/STP. Failing the abort request this way will cause the * SCSI error handler thread to escalate to LUN reset @@ -1481,86 +1483,94 @@ isci_task_request_complete(struct isci_host *ihost, complete(tmf_complete); } -/** - * isci_bus_reset_handler() - This function performs a target reset of the - * device referenced by "cmd'. This function is exported through the - * "struct scsi_host_template" structure such that it is called when an I/O - * recovery process has escalated to a target reset. Note that this function - * is called from the scsi error handler event thread, so may block on calls. - * @scsi_cmd: This parameter specifies the target to be reset. - * - * SUCCESS if the reset process was successful, else FAILED. - */ -int isci_bus_reset_handler(struct scsi_cmnd *cmd) +static int isci_reset_device(struct domain_device *dev, int hard_reset) { - struct domain_device *dev = cmd_to_domain_dev(cmd); - struct isci_host *isci_host = dev_to_ihost(dev); - unsigned long flags = 0; + struct isci_remote_device *idev = dev->lldd_dev; + struct sas_phy *phy = sas_find_local_phy(dev); + struct isci_host *ihost = dev_to_ihost(dev); enum sci_status status; - int base_status; - struct isci_remote_device *isci_dev = dev->lldd_dev; + unsigned long flags; + int rc; - dev_dbg(&isci_host->pdev->dev, - "%s: cmd %p, isci_dev %p\n", - __func__, cmd, isci_dev); + dev_dbg(&ihost->pdev->dev, "%s: idev %p\n", __func__, idev); - if (!isci_dev) { - dev_warn(&isci_host->pdev->dev, - "%s: isci_dev is GONE!\n", + if (!idev) { + dev_warn(&ihost->pdev->dev, + "%s: idev is GONE!\n", __func__); return TMF_RESP_FUNC_COMPLETE; /* Nothing to reset. */ } - spin_lock_irqsave(&isci_host->scic_lock, flags); - status = scic_remote_device_reset(&isci_dev->sci); + spin_lock_irqsave(&ihost->scic_lock, flags); + status = scic_remote_device_reset(&idev->sci); if (status != SCI_SUCCESS) { - spin_unlock_irqrestore(&isci_host->scic_lock, flags); + spin_unlock_irqrestore(&ihost->scic_lock, flags); - scmd_printk(KERN_WARNING, cmd, - "%s: scic_remote_device_reset(%p) returned %d!\n", - __func__, isci_dev, status); + dev_warn(&ihost->pdev->dev, + "%s: scic_remote_device_reset(%p) returned %d!\n", + __func__, idev, status); return TMF_RESP_FUNC_FAILED; } - spin_unlock_irqrestore(&isci_host->scic_lock, flags); + spin_unlock_irqrestore(&ihost->scic_lock, flags); /* Make sure all pending requests are able to be fully terminated. */ - isci_device_clear_reset_pending(isci_host, isci_dev); + isci_device_clear_reset_pending(ihost, idev); - /* Terminate in-progress I/O now. */ - isci_remote_device_nuke_requests(isci_host, isci_dev); + rc = sas_phy_reset(phy, hard_reset); + msleep(2000); /* just like mvsas */ - /* Call into the libsas default handler (which calls sas_phy_reset). */ - base_status = sas_eh_bus_reset_handler(cmd); + /* Terminate in-progress I/O now. */ + isci_remote_device_nuke_requests(ihost, idev); - if (base_status != SUCCESS) { + spin_lock_irqsave(&ihost->scic_lock, flags); + status = scic_remote_device_reset_complete(&idev->sci); + spin_unlock_irqrestore(&ihost->scic_lock, flags); - /* There can be cases where the resets to individual devices - * behind an expander will fail because of an unplug of the - * expander itself. - */ - scmd_printk(KERN_WARNING, cmd, - "%s: sas_eh_bus_reset_handler(%p) returned %d!\n", - __func__, cmd, base_status); + if (status != SCI_SUCCESS) { + dev_warn(&ihost->pdev->dev, + "%s: scic_remote_device_reset_complete(%p) " + "returned %d!\n", __func__, idev, status); } - /* WHAT TO DO HERE IF sas_phy_reset FAILS? */ - spin_lock_irqsave(&isci_host->scic_lock, flags); - status = scic_remote_device_reset_complete(&isci_dev->sci); - spin_unlock_irqrestore(&isci_host->scic_lock, flags); + dev_dbg(&ihost->pdev->dev, "%s: idev %p complete.\n", __func__, idev); - if (status != SCI_SUCCESS) { - scmd_printk(KERN_WARNING, cmd, - "%s: scic_remote_device_reset_complete(%p) " - "returned %d!\n", - __func__, isci_dev, status); - } - /* WHAT TO DO HERE IF scic_remote_device_reset_complete FAILS? */ + return rc; +} - dev_dbg(&isci_host->pdev->dev, - "%s: cmd %p, isci_dev %p complete.\n", - __func__, cmd, isci_dev); +int isci_task_I_T_nexus_reset(struct domain_device *dev) +{ + struct isci_host *ihost = dev_to_ihost(dev); + int ret = TMF_RESP_FUNC_FAILED, hard_reset = 1; + struct isci_remote_device *idev; + unsigned long flags; + + /* XXX mvsas is not protecting against ->lldd_dev_gone(), are we + * being too paranoid, or is mvsas busted?! + */ + spin_lock_irqsave(&ihost->scic_lock, flags); + idev = dev->lldd_dev; + if (!idev || !test_bit(IDEV_EH, &idev->flags)) + ret = TMF_RESP_FUNC_COMPLETE; + spin_unlock_irqrestore(&ihost->scic_lock, flags); + + if (ret == TMF_RESP_FUNC_COMPLETE) + return ret; + + if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP)) + hard_reset = 0; + + return isci_reset_device(dev, hard_reset); +} + +int isci_bus_reset_handler(struct scsi_cmnd *cmd) +{ + struct domain_device *dev = sdev_to_domain_dev(cmd->device); + int hard_reset = 1; + + if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP)) + hard_reset = 0; - return TMF_RESP_FUNC_COMPLETE; + return isci_reset_device(dev, hard_reset); } -- 2.7.4