zfcp_scsi.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 911 行 · 第 1/2 页

	 * Race condition between normal (late) completion and abort has
	 * to be avoided.
	 * The entirity of all accesses to scsi_req have to be atomic.
	 * scsi_req is usually part of the fsf_req and thus we block the
	 * release of fsf_req as long as we need to access scsi_req.
	 */
	write_lock_irqsave(&adapter->abort_lock, flags);

	/*
	 * Check whether command has just completed and can not be aborted.
	 * Even if the command has just been completed late, we can access
	 * scpnt since the SCSI stack does not release it at least until
	 * this routine returns. (scpnt is parameter passed to this routine
	 * and must not disappear during abort even on late completion.)
	 */
	req_data = (union zfcp_req_data *) scpnt->host_scribble;
	/* DEBUG */
	ZFCP_LOG_DEBUG("req_data=%p\n", req_data);
	if (!req_data) {
		ZFCP_LOG_DEBUG("late command completion overtook abort\n");
		/*
		 * That's it.
		 * Do not initiate abort but return SUCCESS.
		 */
		write_unlock_irqrestore(&adapter->abort_lock, flags);
		retval = SUCCESS;
		strncpy(dbf_result, "##late1", ZFCP_ABORT_DBF_LENGTH);
		goto out;
	}

	/* Figure out which fsf_req needs to be aborted. */
	old_fsf_req = req_data->send_fcp_command_task.fsf_req;

	dbf_fsf_req = (unsigned long) old_fsf_req;
	dbf_timeout =
	    (jiffies - req_data->send_fcp_command_task.start_jiffies) / HZ;

	ZFCP_LOG_DEBUG("old_fsf_req=%p\n", old_fsf_req);
	if (!old_fsf_req) {
		write_unlock_irqrestore(&adapter->abort_lock, flags);
		ZFCP_LOG_NORMAL("bug: no old fsf request found\n");
		ZFCP_LOG_NORMAL("req_data:\n");
		ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
			      (char *) req_data, sizeof (union zfcp_req_data));
		ZFCP_LOG_NORMAL("scsi_cmnd:\n");
		ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
			      (char *) scpnt, sizeof (struct scsi_cmnd));
		retval = FAILED;
		strncpy(dbf_result, "##bug:r", ZFCP_ABORT_DBF_LENGTH);
		goto out;
	}
	old_fsf_req->data.send_fcp_command_task.scsi_cmnd = NULL;
	/* mark old request as being aborted */
	old_fsf_req->status |= ZFCP_STATUS_FSFREQ_ABORTING;
	/*
	 * We have to collect all information (e.g. unit) needed by 
	 * zfcp_fsf_abort_fcp_command before calling that routine
	 * since that routine is not allowed to access
	 * fsf_req which it is going to abort.
	 * This is because of we need to release fsf_req_list_lock
	 * before calling zfcp_fsf_abort_fcp_command.
	 * Since this lock will not be held, fsf_req may complete
	 * late and may be released meanwhile.
	 */
	ZFCP_LOG_DEBUG("unit 0x%016Lx (%p)\n", unit->fcp_lun, unit);

	/*
	 * We block (call schedule)
	 * That's why we must release the lock and enable the
	 * interrupts before.
	 * On the other hand we do not need the lock anymore since
	 * all critical accesses to scsi_req are done.
	 */
	write_unlock_irqrestore(&adapter->abort_lock, flags);
	/* call FSF routine which does the abort */
	new_fsf_req = zfcp_fsf_abort_fcp_command((unsigned long) old_fsf_req,
						 adapter, unit, 0);
	ZFCP_LOG_DEBUG("new_fsf_req=%p\n", new_fsf_req);
	if (!new_fsf_req) {
		retval = FAILED;
		ZFCP_LOG_NORMAL("error: initiation of Abort FCP Cmnd "
				"failed\n");
		strncpy(dbf_result, "##nores", ZFCP_ABORT_DBF_LENGTH);
		goto out;
	}

	/* wait for completion of abort */
	ZFCP_LOG_DEBUG("waiting for cleanup...\n");
#if 1
	/*
	 * FIXME:
	 * copying zfcp_fsf_req_wait_and_cleanup code is not really nice
	 */
	__wait_event(new_fsf_req->completion_wq,
		     new_fsf_req->status & ZFCP_STATUS_FSFREQ_COMPLETED);
	status = new_fsf_req->status;
	dbf_fsf_status = new_fsf_req->qtcb->header.fsf_status;
	/*
	 * Ralphs special debug load provides timestamps in the FSF
	 * status qualifier. This might be specified later if being
	 * useful for debugging aborts.
	 */
	dbf_fsf_qual[0] =
	    *(u64 *) & new_fsf_req->qtcb->header.fsf_status_qual.word[0];
	dbf_fsf_qual[1] =
	    *(u64 *) & new_fsf_req->qtcb->header.fsf_status_qual.word[2];
	zfcp_fsf_req_cleanup(new_fsf_req);
#else
	retval = zfcp_fsf_req_wait_and_cleanup(new_fsf_req,
					       ZFCP_UNINTERRUPTIBLE, &status);
#endif
	ZFCP_LOG_DEBUG("Waiting for cleanup complete, status=0x%x\n", status);
	/* status should be valid since signals were not permitted */
	if (status & ZFCP_STATUS_FSFREQ_ABORTSUCCEEDED) {
		retval = SUCCESS;
		strncpy(dbf_result, "##succ", ZFCP_ABORT_DBF_LENGTH);
	} else if (status & ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED) {
		retval = SUCCESS;
		strncpy(dbf_result, "##late2", ZFCP_ABORT_DBF_LENGTH);
	} else {
		retval = FAILED;
		strncpy(dbf_result, "##fail", ZFCP_ABORT_DBF_LENGTH);
	}

 out:
	debug_event(adapter->abort_dbf, 1, &dbf_scsi_cmnd, sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_opcode, ZFCP_ABORT_DBF_LENGTH);
	debug_event(adapter->abort_dbf, 1, &dbf_wwn, sizeof (wwn_t));
	debug_event(adapter->abort_dbf, 1, &dbf_fcp_lun, sizeof (fcp_lun_t));
	debug_event(adapter->abort_dbf, 1, &dbf_retries, sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_allowed, sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_timeout, sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_fsf_req, sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_fsf_status, sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_fsf_qual[0], sizeof (u64));
	debug_event(adapter->abort_dbf, 1, &dbf_fsf_qual[1], sizeof (u64));
	debug_text_event(adapter->abort_dbf, 1, dbf_result);

	spin_lock_irq(scsi_host->host_lock);
	return retval;
}

/*
 * function:	zfcp_scsi_eh_device_reset_handler
 *
 * purpose:
 *
 * returns:
 */
int
zfcp_scsi_eh_device_reset_handler(struct scsi_cmnd *scpnt)
{
	int retval;
	struct zfcp_unit *unit = (struct zfcp_unit *) scpnt->device->hostdata;
	struct Scsi_Host *scsi_host = scpnt->device->host;

	spin_unlock_irq(scsi_host->host_lock);

	if (!unit) {
		ZFCP_LOG_NORMAL("bug: Tried reset for nonexistent unit\n");
		retval = SUCCESS;
		goto out;
	}
	ZFCP_LOG_NORMAL("resetting unit 0x%016Lx\n", unit->fcp_lun);

	/*
	 * If we do not know whether the unit supports 'logical unit reset'
	 * then try 'logical unit reset' and proceed with 'target reset'
	 * if 'logical unit reset' fails.
	 * If the unit is known not to support 'logical unit reset' then
	 * skip 'logical unit reset' and try 'target reset' immediately.
	 */
	if (!atomic_test_mask(ZFCP_STATUS_UNIT_NOTSUPPUNITRESET,
			      &unit->status)) {
		retval =
		    zfcp_task_management_function(unit, LOGICAL_UNIT_RESET);
		if (retval) {
			ZFCP_LOG_DEBUG("unit reset failed (unit=%p)\n", unit);
			if (retval == -ENOTSUPP)
				atomic_set_mask
				    (ZFCP_STATUS_UNIT_NOTSUPPUNITRESET,
				     &unit->status);
			/* fall through and try 'target reset' next */
		} else {
			ZFCP_LOG_DEBUG("unit reset succeeded (unit=%p)\n",
				       unit);
			/* avoid 'target reset' */
			retval = SUCCESS;
			goto out;
		}
	}
	retval = zfcp_task_management_function(unit, TARGET_RESET);
	if (retval) {
		ZFCP_LOG_DEBUG("target reset failed (unit=%p)\n", unit);
		retval = FAILED;
	} else {
		ZFCP_LOG_DEBUG("target reset succeeded (unit=%p)\n", unit);
		retval = SUCCESS;
	}
 out:
	spin_lock_irq(scsi_host->host_lock);
	return retval;
}

static int
zfcp_task_management_function(struct zfcp_unit *unit, u8 tm_flags)
{
	struct zfcp_adapter *adapter = unit->port->adapter;
	int retval;
	int status;
	struct zfcp_fsf_req *fsf_req;

	/* issue task management function */
	fsf_req = zfcp_fsf_send_fcp_command_task_management
		(adapter, unit, tm_flags, 0);
	if (!fsf_req) {
		ZFCP_LOG_INFO("error: creation of task management request "
			      "failed for unit 0x%016Lx on port 0x%016Lx on  "
			      "adapter %s\n", unit->fcp_lun, unit->port->wwpn,
			      zfcp_get_busid_by_adapter(adapter));
		retval = -ENOMEM;
		goto out;
	}

	retval = zfcp_fsf_req_wait_and_cleanup(fsf_req,
					       ZFCP_UNINTERRUPTIBLE, &status);
	/*
	 * check completion status of task management function
	 * (status should always be valid since no signals permitted)
	 */
	if (status & ZFCP_STATUS_FSFREQ_TMFUNCFAILED)
		retval = -EIO;
	else if (status & ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP)
		retval = -ENOTSUPP;
	else
		retval = 0;
 out:
	return retval;
}

/*
 * function:	zfcp_scsi_eh_bus_reset_handler
 *
 * purpose:
 *
 * returns:
 */
int
zfcp_scsi_eh_bus_reset_handler(struct scsi_cmnd *scpnt)
{
	int retval = 0;
	struct zfcp_unit *unit;
	struct Scsi_Host *scsi_host = scpnt->device->host;

	spin_unlock_irq(scsi_host->host_lock);

	unit = (struct zfcp_unit *) scpnt->device->hostdata;
	ZFCP_LOG_NORMAL("bus reset because of problems with "
			"unit 0x%016Lx\n", unit->fcp_lun);
	zfcp_erp_adapter_reopen(unit->port->adapter, 0);
	zfcp_erp_wait(unit->port->adapter);
	retval = SUCCESS;

	spin_lock_irq(scsi_host->host_lock);
	return retval;
}

/*
 * function:	zfcp_scsi_eh_host_reset_handler
 *
 * purpose:
 *
 * returns:
 */
int
zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
{
	int retval = 0;
	struct zfcp_unit *unit;
	struct Scsi_Host *scsi_host = scpnt->device->host;

	spin_unlock_irq(scsi_host->host_lock);

	unit = (struct zfcp_unit *) scpnt->device->hostdata;
	ZFCP_LOG_NORMAL("host reset because of problems with "
			"unit 0x%016Lx\n", unit->fcp_lun);
	zfcp_erp_adapter_reopen(unit->port->adapter, 0);
	zfcp_erp_wait(unit->port->adapter);
	retval = SUCCESS;

	spin_lock_irq(scsi_host->host_lock);
	return retval;
}

/*
 * function:	
 *
 * purpose:	
 *
 * returns:
 */
int
zfcp_adapter_scsi_register(struct zfcp_adapter *adapter)
{
	int retval = 0;
	static unsigned int unique_id = 0;

	/* register adapter as SCSI host with mid layer of SCSI stack */
	adapter->scsi_host = scsi_host_alloc(&zfcp_data.scsi_host_template,
					     sizeof (struct zfcp_adapter *));
	if (!adapter->scsi_host) {
		ZFCP_LOG_NORMAL("error: registration with SCSI stack failed "
				"for adapter %s ",
				zfcp_get_busid_by_adapter(adapter));
		retval = -EIO;
		goto out;
	}
	ZFCP_LOG_DEBUG("host registered, scsi_host=%p\n", adapter->scsi_host);

	/* tell the SCSI stack some characteristics of this adapter */
	adapter->scsi_host->max_id = 1;
	adapter->scsi_host->max_lun = 1;
	adapter->scsi_host->max_channel = 0;
	adapter->scsi_host->unique_id = unique_id++;	/* FIXME */
	adapter->scsi_host->max_cmd_len = ZFCP_MAX_SCSI_CMND_LENGTH;
	adapter->scsi_host->transportt = zfcp_transport_template;
	/*
	 * Reverse mapping of the host number to avoid race condition
	 */
	adapter->scsi_host_no = adapter->scsi_host->host_no;

	/*
	 * save a pointer to our own adapter data structure within
	 * hostdata field of SCSI host data structure
	 */
	adapter->scsi_host->hostdata[0] = (unsigned long) adapter;

	if (scsi_add_host(adapter->scsi_host, &adapter->ccw_device->dev)) {
		scsi_host_put(adapter->scsi_host);
		retval = -EIO;
		goto out;
	}
	atomic_set_mask(ZFCP_STATUS_ADAPTER_REGISTERED, &adapter->status);
 out:
	return retval;
}

/*
 * function:	
 *
 * purpose:	
 *
 * returns:
 */
void
zfcp_adapter_scsi_unregister(struct zfcp_adapter *adapter)
{
	struct Scsi_Host *shost;

	shost = adapter->scsi_host;
	if (!shost)
		return;
	scsi_remove_host(shost);
	scsi_host_put(shost);
	adapter->scsi_host = NULL;
	adapter->scsi_host_no = 0;
	atomic_clear_mask(ZFCP_STATUS_ADAPTER_REGISTERED, &adapter->status);

	return;
}


void
zfcp_fsf_start_scsi_er_timer(struct zfcp_adapter *adapter)
{
	adapter->scsi_er_timer.function = zfcp_fsf_scsi_er_timeout_handler;
	adapter->scsi_er_timer.data = (unsigned long) adapter;
	adapter->scsi_er_timer.expires = jiffies + ZFCP_SCSI_ER_TIMEOUT;
	add_timer(&adapter->scsi_er_timer);
}

/*
 * Support functions for FC transport class
 */
static void
zfcp_get_port_id(struct scsi_device *sdev)
{
	struct zfcp_unit *unit;

	unit = (struct zfcp_unit *) sdev->hostdata;
	fc_port_id(sdev) = unit->port->d_id;
}

static void
zfcp_get_port_name(struct scsi_device *sdev)
{
	struct zfcp_unit *unit;

	unit = (struct zfcp_unit *) sdev->hostdata;
	fc_port_name(sdev) = unit->port->wwpn;
}

static void
zfcp_get_node_name(struct scsi_device *sdev)
{
	struct zfcp_unit *unit;

	unit = (struct zfcp_unit *) sdev->hostdata;
	fc_node_name(sdev) = unit->port->wwnn;
}

struct fc_function_template zfcp_transport_functions = {
	.get_port_id = zfcp_get_port_id,
	.get_port_name = zfcp_get_port_name,
	.get_node_name = zfcp_get_node_name,
	.show_port_id = 1,
	.show_port_name = 1,
	.show_node_name = 1,
};

/**
 * ZFCP_DEFINE_SCSI_ATTR
 * @_name:   name of show attribute
 * @_format: format string
 * @_value:  value to print
 *
 * Generates attribute for a unit.
 */
#define ZFCP_DEFINE_SCSI_ATTR(_name, _format, _value)                    \
static ssize_t zfcp_sysfs_scsi_##_name##_show(struct device *dev,        \
                                              char *buf)                 \
{                                                                        \
        struct scsi_device *sdev;                                        \
        struct zfcp_unit *unit;                                          \
                                                                         \
        sdev = to_scsi_device(dev);                                      \
        unit = sdev->hostdata;                                           \
        return sprintf(buf, _format, _value);                            \
}                                                                        \
                                                                         \
static DEVICE_ATTR(_name, S_IRUGO, zfcp_sysfs_scsi_##_name##_show, NULL);

ZFCP_DEFINE_SCSI_ATTR(hba_id, "%s\n", zfcp_get_busid_by_unit(unit));
ZFCP_DEFINE_SCSI_ATTR(wwpn, "0x%016llx\n", unit->port->wwpn);
ZFCP_DEFINE_SCSI_ATTR(fcp_lun, "0x%016llx\n", unit->fcp_lun);

static struct device_attribute *zfcp_sysfs_sdev_attrs[] = {
	&dev_attr_fcp_lun,
	&dev_attr_wwpn,
	&dev_attr_hba_id,
	NULL
};

#undef ZFCP_LOG_AREA