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Commit fea9d6c7 authored by Volker Sameske's avatar Volker Sameske Committed by James Bottomley
Browse files

[SCSI] zfcp: improve management of request IDs 



Improve request handling. Use hash table to manage request IDs.

Signed-off-by: default avatarVolker Sameske <sameske@de.ibm.com>
Signed-off-by: default avatarAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent c2602c48

drivers/s390/scsi/zfcp_aux.c

+111 −9
Original line number Diff line number Diff line
@@ -112,6 +112,105 @@ _zfcp_hex_dump(char *addr, int count) 
		printk("\n");

}





/****************************************************************/

/****** Functions to handle the request ID hash table    ********/

/****************************************************************/



#define ZFCP_LOG_AREA			ZFCP_LOG_AREA_FSF



static int zfcp_reqlist_init(struct zfcp_adapter *adapter)

{

	int i;



	adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),

				    GFP_KERNEL);



	if (!adapter->req_list)

		return -ENOMEM;



	for (i=0; i<REQUEST_LIST_SIZE; i++)

		INIT_LIST_HEAD(&adapter->req_list[i]);



	return 0;

}



static void zfcp_reqlist_free(struct zfcp_adapter *adapter)

{

	struct zfcp_fsf_req *request, *tmp;

	unsigned int i;



	for (i=0; i<REQUEST_LIST_SIZE; i++) {

		if (list_empty(&adapter->req_list[i]))

			continue;



		list_for_each_entry_safe(request, tmp,

					 &adapter->req_list[i], list)

			list_del(&request->list);

	}



	kfree(adapter->req_list);

}



void zfcp_reqlist_add(struct zfcp_adapter *adapter,

		      struct zfcp_fsf_req *fsf_req)

{

	unsigned int i;



	i = fsf_req->req_id % REQUEST_LIST_SIZE;

	list_add_tail(&fsf_req->list, &adapter->req_list[i]);

}



void zfcp_reqlist_remove(struct zfcp_adapter *adapter, unsigned long req_id)

{

	struct zfcp_fsf_req *request, *tmp;

	unsigned int i, counter;

	u64 dbg_tmp[2];



	i = req_id % REQUEST_LIST_SIZE;

	BUG_ON(list_empty(&adapter->req_list[i]));



	counter = 0;

	list_for_each_entry_safe(request, tmp, &adapter->req_list[i], list) {

		if (request->req_id == req_id) {

			dbg_tmp[0] = (u64) atomic_read(&adapter->reqs_active);

			dbg_tmp[1] = (u64) counter;

			debug_event(adapter->erp_dbf, 4, (void *) dbg_tmp, 16);

			list_del(&request->list);

			break;

		}

		counter++;

	}

}



struct zfcp_fsf_req *zfcp_reqlist_ismember(struct zfcp_adapter *adapter,

					   unsigned long req_id)

{

	struct zfcp_fsf_req *request, *tmp;

	unsigned int i;



	i = req_id % REQUEST_LIST_SIZE;



	list_for_each_entry_safe(request, tmp, &adapter->req_list[i], list)

		if (request->req_id == req_id)

			return request;



	return NULL;

}



int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)

{

	unsigned int i;



	for (i=0; i<REQUEST_LIST_SIZE; i++)

		if (!list_empty(&adapter->req_list[i]))

			return 0;



	return 1;

}



#undef ZFCP_LOG_AREA



/****************************************************************/

/************** Uncategorised Functions *************************/

/****************************************************************/
@@ -961,8 +1060,12 @@ zfcp_adapter_enqueue(struct ccw_device *ccw_device) 
	INIT_LIST_HEAD(&adapter->port_remove_lh);



	/* initialize list of fsf requests */

	spin_lock_init(&adapter->fsf_req_list_lock);

	INIT_LIST_HEAD(&adapter->fsf_req_list_head);

	spin_lock_init(&adapter->req_list_lock);

	retval = zfcp_reqlist_init(adapter);

	if (retval) {

		ZFCP_LOG_INFO("request list initialization failed\n");

		goto failed_low_mem_buffers;

	}



	/* initialize debug locks */
@@ -1041,8 +1144,6 @@ zfcp_adapter_enqueue(struct ccw_device *ccw_device) 
 *		!0 - struct zfcp_adapter  data structure could not be removed

 *			(e.g. still used)

 * locks:	adapter list write lock is assumed to be held by caller

 *              adapter->fsf_req_list_lock is taken and released within this 

 *              function and must not be held on entry

 */

void

zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
@@ -1054,14 +1155,14 @@ zfcp_adapter_dequeue(struct zfcp_adapter *adapter) 
	zfcp_sysfs_adapter_remove_files(&adapter->ccw_device->dev);

	dev_set_drvdata(&adapter->ccw_device->dev, NULL);

	/* sanity check: no pending FSF requests */

	spin_lock_irqsave(&adapter->fsf_req_list_lock, flags);

	retval = !list_empty(&adapter->fsf_req_list_head);

	spin_unlock_irqrestore(&adapter->fsf_req_list_lock, flags);

	if (retval) {

	spin_lock_irqsave(&adapter->req_list_lock, flags);

	retval = zfcp_reqlist_isempty(adapter);

	spin_unlock_irqrestore(&adapter->req_list_lock, flags);

	if (!retval) {

		ZFCP_LOG_NORMAL("bug: adapter %s (%p) still in use, "

				"%i requests outstanding\n",

				zfcp_get_busid_by_adapter(adapter), adapter,

				atomic_read(&adapter->fsf_reqs_active));

				atomic_read(&adapter->reqs_active));

		retval = -EBUSY;

		goto out;

	}
@@ -1087,6 +1188,7 @@ zfcp_adapter_dequeue(struct zfcp_adapter *adapter) 
	zfcp_free_low_mem_buffers(adapter);

	/* free memory of adapter data structure and queues */

	zfcp_qdio_free_queues(adapter);

	zfcp_reqlist_free(adapter);

	kfree(adapter->fc_stats);

	kfree(adapter->stats_reset_data);

	ZFCP_LOG_TRACE("freeing adapter structure\n");

drivers/s390/scsi/zfcp_ccw.c

+5 −0
Original line number Diff line number Diff line
@@ -164,6 +164,11 @@ zfcp_ccw_set_online(struct ccw_device *ccw_device) 
	retval = zfcp_adapter_scsi_register(adapter);

	if (retval)

		goto out_scsi_register;



	/* initialize request counter */

	BUG_ON(!zfcp_reqlist_isempty(adapter));

	adapter->req_no = 0;



	zfcp_erp_modify_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING,

				       ZFCP_SET);

	zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED);

drivers/s390/scsi/zfcp_def.h

+6 −5
Original line number Diff line number Diff line
@@ -887,10 +887,10 @@ struct zfcp_adapter { 
						      removed */

	u32			ports;	           /* number of remote ports */

	struct timer_list	scsi_er_timer;     /* SCSI err recovery watch */

	struct list_head	fsf_req_list_head; /* head of FSF req list */

	spinlock_t		fsf_req_list_lock; /* lock for ops on list of

						      FSF requests */

        atomic_t       		fsf_reqs_active;   /* # active FSF reqs */

	atomic_t		reqs_active;	   /* # active FSF reqs */

	unsigned long		req_no;		   /* unique FSF req number */

	struct list_head	*req_list;	   /* list of pending reqs */

	spinlock_t		req_list_lock;	   /* request list lock */

	struct zfcp_qdio_queue	request_queue;	   /* request queue */

	u32			fsf_req_seq_no;	   /* FSF cmnd seq number */

	wait_queue_head_t	request_wq;	   /* can be used to wait for
@@ -986,6 +986,7 @@ struct zfcp_unit { 
/* FSF request */

struct zfcp_fsf_req {

	struct list_head       list;	       /* list of FSF requests */

	unsigned long	       req_id;	       /* unique request ID */

	struct zfcp_adapter    *adapter;       /* adapter request belongs to */

	u8		       sbal_number;    /* nr of SBALs free for use */

	u8		       sbal_first;     /* first SBAL for this request */

drivers/s390/scsi/zfcp_erp.c

+7 −9
Original line number Diff line number Diff line
@@ -848,18 +848,16 @@ zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *erp_action) 
	struct zfcp_adapter *adapter = erp_action->adapter;



	if (erp_action->fsf_req) {

		/* take lock to ensure that request is not being deleted meanwhile */

		spin_lock(&adapter->fsf_req_list_lock);

		/* check whether fsf req does still exist */

		list_for_each_entry(fsf_req, &adapter->fsf_req_list_head, list)

		    if (fsf_req == erp_action->fsf_req)

			break;

		if (fsf_req && (fsf_req->erp_action == erp_action)) {

		/* take lock to ensure that request is not deleted meanwhile */

		spin_lock(&adapter->req_list_lock);

		if ((!zfcp_reqlist_ismember(adapter,

					    erp_action->fsf_req->req_id)) &&

		    (fsf_req->erp_action == erp_action)) {

			/* fsf_req still exists */

			debug_text_event(adapter->erp_dbf, 3, "a_ca_req");

			debug_event(adapter->erp_dbf, 3, &fsf_req,

				    sizeof (unsigned long));

			/* dismiss fsf_req of timed out or dismissed erp_action */

			/* dismiss fsf_req of timed out/dismissed erp_action */

			if (erp_action->status & (ZFCP_STATUS_ERP_DISMISSED |

						  ZFCP_STATUS_ERP_TIMEDOUT)) {

				debug_text_event(adapter->erp_dbf, 3,
@@ -892,7 +890,7 @@ zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *erp_action) 
			 */

			erp_action->fsf_req = NULL;

		}

		spin_unlock(&adapter->fsf_req_list_lock);

		spin_unlock(&adapter->req_list_lock);

	} else

		debug_text_event(adapter->erp_dbf, 3, "a_ca_noreq");

drivers/s390/scsi/zfcp_ext.h

+5 −1
Original line number Diff line number Diff line
@@ -63,7 +63,6 @@ extern int zfcp_qdio_allocate_queues(struct zfcp_adapter *); 
extern void zfcp_qdio_free_queues(struct zfcp_adapter *);

extern int  zfcp_qdio_determine_pci(struct zfcp_qdio_queue *,

				    struct zfcp_fsf_req *);

extern int  zfcp_qdio_reqid_check(struct zfcp_adapter *, void *);



extern volatile struct qdio_buffer_element *zfcp_qdio_sbale_req

	(struct zfcp_fsf_req *, int, int);
@@ -190,5 +189,10 @@ extern void zfcp_scsi_dbf_event_abort(const char *, struct zfcp_adapter *, 
				      struct zfcp_fsf_req *);

extern void zfcp_scsi_dbf_event_devreset(const char *, u8, struct zfcp_unit *,

					 struct scsi_cmnd *);

extern void zfcp_reqlist_add(struct zfcp_adapter *, struct zfcp_fsf_req *);

extern void zfcp_reqlist_remove(struct zfcp_adapter *, unsigned long);

extern struct zfcp_fsf_req *zfcp_reqlist_ismember(struct zfcp_adapter *,

						  unsigned long);

extern int zfcp_reqlist_isempty(struct zfcp_adapter *);



#endif	/* ZFCP_EXT_H */