xref: /linux/drivers/s390/scsi/zfcp_erp.c (revision 5144c534d16529bc469396211131e8935589f833)
1 /*
2  * zfcp device driver
3  *
4  * Error Recovery Procedures (ERP).
5  *
6  * Copyright IBM Corporation 2002, 2010
7  */
8 
9 #define KMSG_COMPONENT "zfcp"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 
12 #include <linux/kthread.h>
13 #include "zfcp_ext.h"
14 #include "zfcp_reqlist.h"
15 
16 #define ZFCP_MAX_ERPS                   3
17 
18 enum zfcp_erp_act_flags {
19 	ZFCP_STATUS_ERP_TIMEDOUT	= 0x10000000,
20 	ZFCP_STATUS_ERP_CLOSE_ONLY	= 0x01000000,
21 	ZFCP_STATUS_ERP_DISMISSING	= 0x00100000,
22 	ZFCP_STATUS_ERP_DISMISSED	= 0x00200000,
23 	ZFCP_STATUS_ERP_LOWMEM		= 0x00400000,
24 	ZFCP_STATUS_ERP_NO_REF		= 0x00800000,
25 };
26 
27 enum zfcp_erp_steps {
28 	ZFCP_ERP_STEP_UNINITIALIZED	= 0x0000,
29 	ZFCP_ERP_STEP_FSF_XCONFIG	= 0x0001,
30 	ZFCP_ERP_STEP_PHYS_PORT_CLOSING	= 0x0010,
31 	ZFCP_ERP_STEP_PORT_CLOSING	= 0x0100,
32 	ZFCP_ERP_STEP_PORT_OPENING	= 0x0800,
33 	ZFCP_ERP_STEP_LUN_CLOSING	= 0x1000,
34 	ZFCP_ERP_STEP_LUN_OPENING	= 0x2000,
35 };
36 
37 enum zfcp_erp_act_type {
38 	ZFCP_ERP_ACTION_REOPEN_LUN         = 1,
39 	ZFCP_ERP_ACTION_REOPEN_PORT	   = 2,
40 	ZFCP_ERP_ACTION_REOPEN_PORT_FORCED = 3,
41 	ZFCP_ERP_ACTION_REOPEN_ADAPTER     = 4,
42 };
43 
44 enum zfcp_erp_act_state {
45 	ZFCP_ERP_ACTION_RUNNING = 1,
46 	ZFCP_ERP_ACTION_READY   = 2,
47 };
48 
49 enum zfcp_erp_act_result {
50 	ZFCP_ERP_SUCCEEDED = 0,
51 	ZFCP_ERP_FAILED    = 1,
52 	ZFCP_ERP_CONTINUES = 2,
53 	ZFCP_ERP_EXIT      = 3,
54 	ZFCP_ERP_DISMISSED = 4,
55 	ZFCP_ERP_NOMEM     = 5,
56 };
57 
58 static void zfcp_erp_adapter_block(struct zfcp_adapter *adapter, int mask)
59 {
60 	zfcp_erp_clear_adapter_status(adapter,
61 				       ZFCP_STATUS_COMMON_UNBLOCKED | mask);
62 }
63 
64 static int zfcp_erp_action_exists(struct zfcp_erp_action *act)
65 {
66 	struct zfcp_erp_action *curr_act;
67 
68 	list_for_each_entry(curr_act, &act->adapter->erp_running_head, list)
69 		if (act == curr_act)
70 			return ZFCP_ERP_ACTION_RUNNING;
71 	return 0;
72 }
73 
74 static void zfcp_erp_action_ready(struct zfcp_erp_action *act)
75 {
76 	struct zfcp_adapter *adapter = act->adapter;
77 
78 	list_move(&act->list, &act->adapter->erp_ready_head);
79 	zfcp_dbf_rec_action("erardy1", act);
80 	wake_up(&adapter->erp_ready_wq);
81 	zfcp_dbf_rec_thread("erardy2", adapter->dbf);
82 }
83 
84 static void zfcp_erp_action_dismiss(struct zfcp_erp_action *act)
85 {
86 	act->status |= ZFCP_STATUS_ERP_DISMISSED;
87 	if (zfcp_erp_action_exists(act) == ZFCP_ERP_ACTION_RUNNING)
88 		zfcp_erp_action_ready(act);
89 }
90 
91 static void zfcp_erp_action_dismiss_lun(struct scsi_device *sdev)
92 {
93 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
94 
95 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
96 		zfcp_erp_action_dismiss(&zfcp_sdev->erp_action);
97 }
98 
99 static void zfcp_erp_action_dismiss_port(struct zfcp_port *port)
100 {
101 	struct scsi_device *sdev;
102 
103 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
104 		zfcp_erp_action_dismiss(&port->erp_action);
105 	else
106 		shost_for_each_device(sdev, port->adapter->scsi_host)
107 			if (sdev_to_zfcp(sdev)->port == port)
108 				zfcp_erp_action_dismiss_lun(sdev);
109 }
110 
111 static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *adapter)
112 {
113 	struct zfcp_port *port;
114 
115 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
116 		zfcp_erp_action_dismiss(&adapter->erp_action);
117 	else {
118 		read_lock(&adapter->port_list_lock);
119 		list_for_each_entry(port, &adapter->port_list, list)
120 		    zfcp_erp_action_dismiss_port(port);
121 		read_unlock(&adapter->port_list_lock);
122 	}
123 }
124 
125 static int zfcp_erp_required_act(int want, struct zfcp_adapter *adapter,
126 				 struct zfcp_port *port,
127 				 struct scsi_device *sdev)
128 {
129 	int need = want;
130 	int l_status, p_status, a_status;
131 	struct zfcp_scsi_dev *zfcp_sdev;
132 
133 	switch (want) {
134 	case ZFCP_ERP_ACTION_REOPEN_LUN:
135 		zfcp_sdev = sdev_to_zfcp(sdev);
136 		l_status = atomic_read(&zfcp_sdev->status);
137 		if (l_status & ZFCP_STATUS_COMMON_ERP_INUSE)
138 			return 0;
139 		p_status = atomic_read(&port->status);
140 		if (!(p_status & ZFCP_STATUS_COMMON_RUNNING) ||
141 		      p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
142 			return 0;
143 		if (!(p_status & ZFCP_STATUS_COMMON_UNBLOCKED))
144 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
145 		/* fall through */
146 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
147 		p_status = atomic_read(&port->status);
148 		if (!(p_status & ZFCP_STATUS_COMMON_OPEN))
149 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
150 		/* fall through */
151 	case ZFCP_ERP_ACTION_REOPEN_PORT:
152 		p_status = atomic_read(&port->status);
153 		if (p_status & ZFCP_STATUS_COMMON_ERP_INUSE)
154 			return 0;
155 		a_status = atomic_read(&adapter->status);
156 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) ||
157 		      a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
158 			return 0;
159 		if (!(a_status & ZFCP_STATUS_COMMON_UNBLOCKED))
160 			need = ZFCP_ERP_ACTION_REOPEN_ADAPTER;
161 		/* fall through */
162 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
163 		a_status = atomic_read(&adapter->status);
164 		if (a_status & ZFCP_STATUS_COMMON_ERP_INUSE)
165 			return 0;
166 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) &&
167 		    !(a_status & ZFCP_STATUS_COMMON_OPEN))
168 			return 0; /* shutdown requested for closed adapter */
169 	}
170 
171 	return need;
172 }
173 
174 static struct zfcp_erp_action *zfcp_erp_setup_act(int need, u32 act_status,
175 						  struct zfcp_adapter *adapter,
176 						  struct zfcp_port *port,
177 						  struct scsi_device *sdev)
178 {
179 	struct zfcp_erp_action *erp_action;
180 	struct zfcp_scsi_dev *zfcp_sdev;
181 
182 	switch (need) {
183 	case ZFCP_ERP_ACTION_REOPEN_LUN:
184 		zfcp_sdev = sdev_to_zfcp(sdev);
185 		if (!(act_status & ZFCP_STATUS_ERP_NO_REF))
186 			if (scsi_device_get(sdev))
187 				return NULL;
188 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
189 				&zfcp_sdev->status);
190 		erp_action = &zfcp_sdev->erp_action;
191 		if (!(atomic_read(&zfcp_sdev->status) &
192 		      ZFCP_STATUS_COMMON_RUNNING))
193 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
194 		break;
195 
196 	case ZFCP_ERP_ACTION_REOPEN_PORT:
197 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
198 		if (!get_device(&port->dev))
199 			return NULL;
200 		zfcp_erp_action_dismiss_port(port);
201 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
202 		erp_action = &port->erp_action;
203 		if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_RUNNING))
204 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
205 		break;
206 
207 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
208 		kref_get(&adapter->ref);
209 		zfcp_erp_action_dismiss_adapter(adapter);
210 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
211 		erp_action = &adapter->erp_action;
212 		if (!(atomic_read(&adapter->status) &
213 		      ZFCP_STATUS_COMMON_RUNNING))
214 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
215 		break;
216 
217 	default:
218 		return NULL;
219 	}
220 
221 	memset(erp_action, 0, sizeof(struct zfcp_erp_action));
222 	erp_action->adapter = adapter;
223 	erp_action->port = port;
224 	erp_action->sdev = sdev;
225 	erp_action->action = need;
226 	erp_action->status = act_status;
227 
228 	return erp_action;
229 }
230 
231 static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
232 				   struct zfcp_port *port,
233 				   struct scsi_device *sdev,
234 				   char *id, void *ref, u32 act_status)
235 {
236 	int retval = 1, need;
237 	struct zfcp_erp_action *act = NULL;
238 
239 	if (!adapter->erp_thread)
240 		return -EIO;
241 
242 	need = zfcp_erp_required_act(want, adapter, port, sdev);
243 	if (!need)
244 		goto out;
245 
246 	act = zfcp_erp_setup_act(need, act_status, adapter, port, sdev);
247 	if (!act)
248 		goto out;
249 	atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING, &adapter->status);
250 	++adapter->erp_total_count;
251 	list_add_tail(&act->list, &adapter->erp_ready_head);
252 	wake_up(&adapter->erp_ready_wq);
253 	zfcp_dbf_rec_thread("eracte1", adapter->dbf);
254 	retval = 0;
255  out:
256 	zfcp_dbf_rec_trigger(id, ref, want, need, act, adapter, port, sdev);
257 	return retval;
258 }
259 
260 static int _zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter,
261 				    int clear_mask, char *id, void *ref)
262 {
263 	zfcp_erp_adapter_block(adapter, clear_mask);
264 	zfcp_scsi_schedule_rports_block(adapter);
265 
266 	/* ensure propagation of failed status to new devices */
267 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
268 		zfcp_erp_set_adapter_status(adapter,
269 					    ZFCP_STATUS_COMMON_ERP_FAILED);
270 		return -EIO;
271 	}
272 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER,
273 				       adapter, NULL, NULL, id, ref, 0);
274 }
275 
276 /**
277  * zfcp_erp_adapter_reopen - Reopen adapter.
278  * @adapter: Adapter to reopen.
279  * @clear: Status flags to clear.
280  * @id: Id for debug trace event.
281  * @ref: Reference for debug trace event.
282  */
283 void zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter, int clear,
284 			     char *id, void *ref)
285 {
286 	unsigned long flags;
287 
288 	zfcp_erp_adapter_block(adapter, clear);
289 	zfcp_scsi_schedule_rports_block(adapter);
290 
291 	write_lock_irqsave(&adapter->erp_lock, flags);
292 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
293 		zfcp_erp_set_adapter_status(adapter,
294 					    ZFCP_STATUS_COMMON_ERP_FAILED);
295 	else
296 		zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER, adapter,
297 					NULL, NULL, id, ref, 0);
298 	write_unlock_irqrestore(&adapter->erp_lock, flags);
299 }
300 
301 /**
302  * zfcp_erp_adapter_shutdown - Shutdown adapter.
303  * @adapter: Adapter to shut down.
304  * @clear: Status flags to clear.
305  * @id: Id for debug trace event.
306  * @ref: Reference for debug trace event.
307  */
308 void zfcp_erp_adapter_shutdown(struct zfcp_adapter *adapter, int clear,
309 			       char *id, void *ref)
310 {
311 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
312 	zfcp_erp_adapter_reopen(adapter, clear | flags, id, ref);
313 }
314 
315 /**
316  * zfcp_erp_port_shutdown - Shutdown port
317  * @port: Port to shut down.
318  * @clear: Status flags to clear.
319  * @id: Id for debug trace event.
320  * @ref: Reference for debug trace event.
321  */
322 void zfcp_erp_port_shutdown(struct zfcp_port *port, int clear, char *id,
323 			    void *ref)
324 {
325 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
326 	zfcp_erp_port_reopen(port, clear | flags, id, ref);
327 }
328 
329 static void zfcp_erp_port_block(struct zfcp_port *port, int clear)
330 {
331 	zfcp_erp_clear_port_status(port,
332 				    ZFCP_STATUS_COMMON_UNBLOCKED | clear);
333 }
334 
335 static void _zfcp_erp_port_forced_reopen(struct zfcp_port *port,
336 					 int clear, char *id, void *ref)
337 {
338 	zfcp_erp_port_block(port, clear);
339 	zfcp_scsi_schedule_rport_block(port);
340 
341 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
342 		return;
343 
344 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
345 				port->adapter, port, NULL, id, ref, 0);
346 }
347 
348 /**
349  * zfcp_erp_port_forced_reopen - Forced close of port and open again
350  * @port: Port to force close and to reopen.
351  * @id: Id for debug trace event.
352  * @ref: Reference for debug trace event.
353  */
354 void zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear, char *id,
355 				 void *ref)
356 {
357 	unsigned long flags;
358 	struct zfcp_adapter *adapter = port->adapter;
359 
360 	write_lock_irqsave(&adapter->erp_lock, flags);
361 	_zfcp_erp_port_forced_reopen(port, clear, id, ref);
362 	write_unlock_irqrestore(&adapter->erp_lock, flags);
363 }
364 
365 static int _zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id,
366 				 void *ref)
367 {
368 	zfcp_erp_port_block(port, clear);
369 	zfcp_scsi_schedule_rport_block(port);
370 
371 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
372 		/* ensure propagation of failed status to new devices */
373 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
374 		return -EIO;
375 	}
376 
377 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT,
378 				       port->adapter, port, NULL, id, ref, 0);
379 }
380 
381 /**
382  * zfcp_erp_port_reopen - trigger remote port recovery
383  * @port: port to recover
384  * @clear_mask: flags in port status to be cleared
385  *
386  * Returns 0 if recovery has been triggered, < 0 if not.
387  */
388 int zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id, void *ref)
389 {
390 	int retval;
391 	unsigned long flags;
392 	struct zfcp_adapter *adapter = port->adapter;
393 
394 	write_lock_irqsave(&adapter->erp_lock, flags);
395 	retval = _zfcp_erp_port_reopen(port, clear, id, ref);
396 	write_unlock_irqrestore(&adapter->erp_lock, flags);
397 
398 	return retval;
399 }
400 
401 static void zfcp_erp_lun_block(struct scsi_device *sdev, int clear_mask)
402 {
403 	zfcp_erp_clear_lun_status(sdev,
404 				  ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask);
405 }
406 
407 static void _zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id,
408 				 void *ref, u32 act_status)
409 {
410 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
411 	struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
412 
413 	zfcp_erp_lun_block(sdev, clear);
414 
415 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
416 		return;
417 
418 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_LUN, adapter,
419 				zfcp_sdev->port, sdev, id, ref, act_status);
420 }
421 
422 /**
423  * zfcp_erp_lun_reopen - initiate reopen of a LUN
424  * @sdev: SCSI device / LUN to be reopened
425  * @clear_mask: specifies flags in LUN status to be cleared
426  * Return: 0 on success, < 0 on error
427  */
428 void zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id,
429 			 void *ref)
430 {
431 	unsigned long flags;
432 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
433 	struct zfcp_port *port = zfcp_sdev->port;
434 	struct zfcp_adapter *adapter = port->adapter;
435 
436 	write_lock_irqsave(&adapter->erp_lock, flags);
437 	_zfcp_erp_lun_reopen(sdev, clear, id, ref, 0);
438 	write_unlock_irqrestore(&adapter->erp_lock, flags);
439 }
440 
441 /**
442  * zfcp_erp_lun_shutdown - Shutdown LUN
443  * @sdev: SCSI device / LUN to shut down.
444  * @clear: Status flags to clear.
445  * @id: Id for debug trace event.
446  * @ref: Reference for debug trace event.
447  */
448 void zfcp_erp_lun_shutdown(struct scsi_device *sdev, int clear, char *id,
449 			   void *ref)
450 {
451 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
452 	zfcp_erp_lun_reopen(sdev, clear | flags, id, ref);
453 }
454 
455 /**
456  * zfcp_erp_lun_shutdown_wait - Shutdown LUN and wait for erp completion
457  * @sdev: SCSI device / LUN to shut down.
458  * @id: Id for debug trace event.
459  *
460  * Do not acquire a reference for the LUN when creating the ERP
461  * action. It is safe, because this function waits for the ERP to
462  * complete first. This allows to shutdown the LUN, even when the SCSI
463  * device is in the state SDEV_DEL when scsi_device_get will fail.
464  */
465 void zfcp_erp_lun_shutdown_wait(struct scsi_device *sdev, char *id)
466 {
467 	unsigned long flags;
468 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
469 	struct zfcp_port *port = zfcp_sdev->port;
470 	struct zfcp_adapter *adapter = port->adapter;
471 	int clear = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
472 
473 	write_lock_irqsave(&adapter->erp_lock, flags);
474 	_zfcp_erp_lun_reopen(sdev, clear, id, NULL, ZFCP_STATUS_ERP_NO_REF);
475 	write_unlock_irqrestore(&adapter->erp_lock, flags);
476 
477 	zfcp_erp_wait(adapter);
478 }
479 
480 static int status_change_set(unsigned long mask, atomic_t *status)
481 {
482 	return (atomic_read(status) ^ mask) & mask;
483 }
484 
485 static void zfcp_erp_adapter_unblock(struct zfcp_adapter *adapter)
486 {
487 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status))
488 		zfcp_dbf_rec_adapter("eraubl1", NULL, adapter->dbf);
489 	atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status);
490 }
491 
492 static void zfcp_erp_port_unblock(struct zfcp_port *port)
493 {
494 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status))
495 		zfcp_dbf_rec_port("erpubl1", NULL, port);
496 	atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status);
497 }
498 
499 static void zfcp_erp_lun_unblock(struct scsi_device *sdev)
500 {
501 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
502 
503 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status))
504 		zfcp_dbf_rec_lun("erlubl1", NULL, sdev);
505 	atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status);
506 }
507 
508 static void zfcp_erp_action_to_running(struct zfcp_erp_action *erp_action)
509 {
510 	list_move(&erp_action->list, &erp_action->adapter->erp_running_head);
511 	zfcp_dbf_rec_action("erator1", erp_action);
512 }
513 
514 static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
515 {
516 	struct zfcp_adapter *adapter = act->adapter;
517 	struct zfcp_fsf_req *req;
518 
519 	if (!act->fsf_req_id)
520 		return;
521 
522 	spin_lock(&adapter->req_list->lock);
523 	req = _zfcp_reqlist_find(adapter->req_list, act->fsf_req_id);
524 	if (req && req->erp_action == act) {
525 		if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
526 				   ZFCP_STATUS_ERP_TIMEDOUT)) {
527 			req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
528 			zfcp_dbf_rec_action("erscf_1", act);
529 			req->erp_action = NULL;
530 		}
531 		if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
532 			zfcp_dbf_rec_action("erscf_2", act);
533 		if (req->status & ZFCP_STATUS_FSFREQ_DISMISSED)
534 			act->fsf_req_id = 0;
535 	} else
536 		act->fsf_req_id = 0;
537 	spin_unlock(&adapter->req_list->lock);
538 }
539 
540 /**
541  * zfcp_erp_notify - Trigger ERP action.
542  * @erp_action: ERP action to continue.
543  * @set_mask: ERP action status flags to set.
544  */
545 void zfcp_erp_notify(struct zfcp_erp_action *erp_action, unsigned long set_mask)
546 {
547 	struct zfcp_adapter *adapter = erp_action->adapter;
548 	unsigned long flags;
549 
550 	write_lock_irqsave(&adapter->erp_lock, flags);
551 	if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING) {
552 		erp_action->status |= set_mask;
553 		zfcp_erp_action_ready(erp_action);
554 	}
555 	write_unlock_irqrestore(&adapter->erp_lock, flags);
556 }
557 
558 /**
559  * zfcp_erp_timeout_handler - Trigger ERP action from timed out ERP request
560  * @data: ERP action (from timer data)
561  */
562 void zfcp_erp_timeout_handler(unsigned long data)
563 {
564 	struct zfcp_erp_action *act = (struct zfcp_erp_action *) data;
565 	zfcp_erp_notify(act, ZFCP_STATUS_ERP_TIMEDOUT);
566 }
567 
568 static void zfcp_erp_memwait_handler(unsigned long data)
569 {
570 	zfcp_erp_notify((struct zfcp_erp_action *)data, 0);
571 }
572 
573 static void zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
574 {
575 	init_timer(&erp_action->timer);
576 	erp_action->timer.function = zfcp_erp_memwait_handler;
577 	erp_action->timer.data = (unsigned long) erp_action;
578 	erp_action->timer.expires = jiffies + HZ;
579 	add_timer(&erp_action->timer);
580 }
581 
582 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
583 				      int clear, char *id, void *ref)
584 {
585 	struct zfcp_port *port;
586 
587 	read_lock(&adapter->port_list_lock);
588 	list_for_each_entry(port, &adapter->port_list, list)
589 		_zfcp_erp_port_reopen(port, clear, id, ref);
590 	read_unlock(&adapter->port_list_lock);
591 }
592 
593 static void _zfcp_erp_lun_reopen_all(struct zfcp_port *port, int clear,
594 				     char *id, void *ref)
595 {
596 	struct scsi_device *sdev;
597 
598 	shost_for_each_device(sdev, port->adapter->scsi_host)
599 		if (sdev_to_zfcp(sdev)->port == port)
600 			_zfcp_erp_lun_reopen(sdev, clear, id, ref, 0);
601 }
602 
603 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
604 {
605 	switch (act->action) {
606 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
607 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1", NULL);
608 		break;
609 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
610 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2", NULL);
611 		break;
612 	case ZFCP_ERP_ACTION_REOPEN_PORT:
613 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3", NULL);
614 		break;
615 	case ZFCP_ERP_ACTION_REOPEN_LUN:
616 		_zfcp_erp_lun_reopen(act->sdev, 0, "ersff_4", NULL, 0);
617 		break;
618 	}
619 }
620 
621 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
622 {
623 	switch (act->action) {
624 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
625 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1", NULL);
626 		break;
627 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
628 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2", NULL);
629 		break;
630 	case ZFCP_ERP_ACTION_REOPEN_PORT:
631 		_zfcp_erp_lun_reopen_all(act->port, 0, "ersfs_3", NULL);
632 		break;
633 	}
634 }
635 
636 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
637 {
638 	unsigned long flags;
639 
640 	read_lock_irqsave(&adapter->erp_lock, flags);
641 	if (list_empty(&adapter->erp_ready_head) &&
642 	    list_empty(&adapter->erp_running_head)) {
643 			atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING,
644 					  &adapter->status);
645 			wake_up(&adapter->erp_done_wqh);
646 	}
647 	read_unlock_irqrestore(&adapter->erp_lock, flags);
648 }
649 
650 static int zfcp_erp_adapter_strategy_open_qdio(struct zfcp_erp_action *act)
651 {
652 	struct zfcp_qdio *qdio = act->adapter->qdio;
653 
654 	if (zfcp_qdio_open(qdio))
655 		return ZFCP_ERP_FAILED;
656 	init_waitqueue_head(&qdio->req_q_wq);
657 	atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &act->adapter->status);
658 	return ZFCP_ERP_SUCCEEDED;
659 }
660 
661 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
662 {
663 	struct zfcp_port *port;
664 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
665 				 adapter->peer_d_id);
666 	if (IS_ERR(port)) /* error or port already attached */
667 		return;
668 	_zfcp_erp_port_reopen(port, 0, "ereptp1", NULL);
669 }
670 
671 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
672 {
673 	int retries;
674 	int sleep = 1;
675 	struct zfcp_adapter *adapter = erp_action->adapter;
676 
677 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
678 
679 	for (retries = 7; retries; retries--) {
680 		atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
681 				  &adapter->status);
682 		write_lock_irq(&adapter->erp_lock);
683 		zfcp_erp_action_to_running(erp_action);
684 		write_unlock_irq(&adapter->erp_lock);
685 		if (zfcp_fsf_exchange_config_data(erp_action)) {
686 			atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
687 					  &adapter->status);
688 			return ZFCP_ERP_FAILED;
689 		}
690 
691 		zfcp_dbf_rec_thread_lock("erasfx1", adapter->dbf);
692 		wait_event(adapter->erp_ready_wq,
693 			   !list_empty(&adapter->erp_ready_head));
694 		zfcp_dbf_rec_thread_lock("erasfx2", adapter->dbf);
695 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
696 			break;
697 
698 		if (!(atomic_read(&adapter->status) &
699 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
700 			break;
701 
702 		ssleep(sleep);
703 		sleep *= 2;
704 	}
705 
706 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
707 			  &adapter->status);
708 
709 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
710 		return ZFCP_ERP_FAILED;
711 
712 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
713 		zfcp_erp_enqueue_ptp_port(adapter);
714 
715 	return ZFCP_ERP_SUCCEEDED;
716 }
717 
718 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
719 {
720 	int ret;
721 	struct zfcp_adapter *adapter = act->adapter;
722 
723 	write_lock_irq(&adapter->erp_lock);
724 	zfcp_erp_action_to_running(act);
725 	write_unlock_irq(&adapter->erp_lock);
726 
727 	ret = zfcp_fsf_exchange_port_data(act);
728 	if (ret == -EOPNOTSUPP)
729 		return ZFCP_ERP_SUCCEEDED;
730 	if (ret)
731 		return ZFCP_ERP_FAILED;
732 
733 	zfcp_dbf_rec_thread_lock("erasox1", adapter->dbf);
734 	wait_event(adapter->erp_ready_wq,
735 		   !list_empty(&adapter->erp_ready_head));
736 	zfcp_dbf_rec_thread_lock("erasox2", adapter->dbf);
737 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
738 		return ZFCP_ERP_FAILED;
739 
740 	return ZFCP_ERP_SUCCEEDED;
741 }
742 
743 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
744 {
745 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
746 		return ZFCP_ERP_FAILED;
747 
748 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
749 		return ZFCP_ERP_FAILED;
750 
751 	if (mempool_resize(act->adapter->pool.status_read_data,
752 			   act->adapter->stat_read_buf_num, GFP_KERNEL))
753 		return ZFCP_ERP_FAILED;
754 
755 	if (mempool_resize(act->adapter->pool.status_read_req,
756 			   act->adapter->stat_read_buf_num, GFP_KERNEL))
757 		return ZFCP_ERP_FAILED;
758 
759 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
760 	if (zfcp_status_read_refill(act->adapter))
761 		return ZFCP_ERP_FAILED;
762 
763 	return ZFCP_ERP_SUCCEEDED;
764 }
765 
766 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
767 {
768 	struct zfcp_adapter *adapter = act->adapter;
769 
770 	/* close queues to ensure that buffers are not accessed by adapter */
771 	zfcp_qdio_close(adapter->qdio);
772 	zfcp_fsf_req_dismiss_all(adapter);
773 	adapter->fsf_req_seq_no = 0;
774 	zfcp_fc_wka_ports_force_offline(adapter->gs);
775 	/* all ports and LUNs are closed */
776 	zfcp_erp_clear_adapter_status(adapter, ZFCP_STATUS_COMMON_OPEN);
777 
778 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
779 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
780 }
781 
782 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
783 {
784 	struct zfcp_adapter *adapter = act->adapter;
785 
786 	if (zfcp_erp_adapter_strategy_open_qdio(act)) {
787 		atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
788 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
789 				  &adapter->status);
790 		return ZFCP_ERP_FAILED;
791 	}
792 
793 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
794 		zfcp_erp_adapter_strategy_close(act);
795 		return ZFCP_ERP_FAILED;
796 	}
797 
798 	atomic_set_mask(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
799 
800 	return ZFCP_ERP_SUCCEEDED;
801 }
802 
803 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
804 {
805 	struct zfcp_adapter *adapter = act->adapter;
806 
807 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
808 		zfcp_erp_adapter_strategy_close(act);
809 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
810 			return ZFCP_ERP_EXIT;
811 	}
812 
813 	if (zfcp_erp_adapter_strategy_open(act)) {
814 		ssleep(8);
815 		return ZFCP_ERP_FAILED;
816 	}
817 
818 	return ZFCP_ERP_SUCCEEDED;
819 }
820 
821 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
822 {
823 	int retval;
824 
825 	retval = zfcp_fsf_close_physical_port(act);
826 	if (retval == -ENOMEM)
827 		return ZFCP_ERP_NOMEM;
828 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
829 	if (retval)
830 		return ZFCP_ERP_FAILED;
831 
832 	return ZFCP_ERP_CONTINUES;
833 }
834 
835 static void zfcp_erp_port_strategy_clearstati(struct zfcp_port *port)
836 {
837 	atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED, &port->status);
838 }
839 
840 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
841 {
842 	struct zfcp_port *port = erp_action->port;
843 	int status = atomic_read(&port->status);
844 
845 	switch (erp_action->step) {
846 	case ZFCP_ERP_STEP_UNINITIALIZED:
847 		zfcp_erp_port_strategy_clearstati(port);
848 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
849 		    (status & ZFCP_STATUS_COMMON_OPEN))
850 			return zfcp_erp_port_forced_strategy_close(erp_action);
851 		else
852 			return ZFCP_ERP_FAILED;
853 
854 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
855 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
856 			return ZFCP_ERP_SUCCEEDED;
857 	}
858 	return ZFCP_ERP_FAILED;
859 }
860 
861 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
862 {
863 	int retval;
864 
865 	retval = zfcp_fsf_close_port(erp_action);
866 	if (retval == -ENOMEM)
867 		return ZFCP_ERP_NOMEM;
868 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
869 	if (retval)
870 		return ZFCP_ERP_FAILED;
871 	return ZFCP_ERP_CONTINUES;
872 }
873 
874 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
875 {
876 	int retval;
877 
878 	retval = zfcp_fsf_open_port(erp_action);
879 	if (retval == -ENOMEM)
880 		return ZFCP_ERP_NOMEM;
881 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
882 	if (retval)
883 		return ZFCP_ERP_FAILED;
884 	return ZFCP_ERP_CONTINUES;
885 }
886 
887 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
888 {
889 	struct zfcp_adapter *adapter = act->adapter;
890 	struct zfcp_port *port = act->port;
891 
892 	if (port->wwpn != adapter->peer_wwpn) {
893 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
894 		return ZFCP_ERP_FAILED;
895 	}
896 	port->d_id = adapter->peer_d_id;
897 	return zfcp_erp_port_strategy_open_port(act);
898 }
899 
900 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
901 {
902 	struct zfcp_adapter *adapter = act->adapter;
903 	struct zfcp_port *port = act->port;
904 	int p_status = atomic_read(&port->status);
905 
906 	switch (act->step) {
907 	case ZFCP_ERP_STEP_UNINITIALIZED:
908 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
909 	case ZFCP_ERP_STEP_PORT_CLOSING:
910 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
911 			return zfcp_erp_open_ptp_port(act);
912 		if (!port->d_id) {
913 			zfcp_fc_trigger_did_lookup(port);
914 			return ZFCP_ERP_EXIT;
915 		}
916 		return zfcp_erp_port_strategy_open_port(act);
917 
918 	case ZFCP_ERP_STEP_PORT_OPENING:
919 		/* D_ID might have changed during open */
920 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
921 			if (!port->d_id) {
922 				zfcp_fc_trigger_did_lookup(port);
923 				return ZFCP_ERP_EXIT;
924 			}
925 			return ZFCP_ERP_SUCCEEDED;
926 		}
927 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
928 			port->d_id = 0;
929 			return ZFCP_ERP_FAILED;
930 		}
931 		/* fall through otherwise */
932 	}
933 	return ZFCP_ERP_FAILED;
934 }
935 
936 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
937 {
938 	struct zfcp_port *port = erp_action->port;
939 	int p_status = atomic_read(&port->status);
940 
941 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
942 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
943 		goto close_init_done;
944 
945 	switch (erp_action->step) {
946 	case ZFCP_ERP_STEP_UNINITIALIZED:
947 		zfcp_erp_port_strategy_clearstati(port);
948 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
949 			return zfcp_erp_port_strategy_close(erp_action);
950 		break;
951 
952 	case ZFCP_ERP_STEP_PORT_CLOSING:
953 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
954 			return ZFCP_ERP_FAILED;
955 		break;
956 	}
957 
958 close_init_done:
959 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
960 		return ZFCP_ERP_EXIT;
961 
962 	return zfcp_erp_port_strategy_open_common(erp_action);
963 }
964 
965 static void zfcp_erp_lun_strategy_clearstati(struct scsi_device *sdev)
966 {
967 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
968 
969 	atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED |
970 			  ZFCP_STATUS_LUN_SHARED | ZFCP_STATUS_LUN_READONLY,
971 			  &zfcp_sdev->status);
972 }
973 
974 static int zfcp_erp_lun_strategy_close(struct zfcp_erp_action *erp_action)
975 {
976 	int retval = zfcp_fsf_close_lun(erp_action);
977 	if (retval == -ENOMEM)
978 		return ZFCP_ERP_NOMEM;
979 	erp_action->step = ZFCP_ERP_STEP_LUN_CLOSING;
980 	if (retval)
981 		return ZFCP_ERP_FAILED;
982 	return ZFCP_ERP_CONTINUES;
983 }
984 
985 static int zfcp_erp_lun_strategy_open(struct zfcp_erp_action *erp_action)
986 {
987 	int retval = zfcp_fsf_open_lun(erp_action);
988 	if (retval == -ENOMEM)
989 		return ZFCP_ERP_NOMEM;
990 	erp_action->step = ZFCP_ERP_STEP_LUN_OPENING;
991 	if (retval)
992 		return  ZFCP_ERP_FAILED;
993 	return ZFCP_ERP_CONTINUES;
994 }
995 
996 static int zfcp_erp_lun_strategy(struct zfcp_erp_action *erp_action)
997 {
998 	struct scsi_device *sdev = erp_action->sdev;
999 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1000 
1001 	switch (erp_action->step) {
1002 	case ZFCP_ERP_STEP_UNINITIALIZED:
1003 		zfcp_erp_lun_strategy_clearstati(sdev);
1004 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
1005 			return zfcp_erp_lun_strategy_close(erp_action);
1006 		/* already closed, fall through */
1007 	case ZFCP_ERP_STEP_LUN_CLOSING:
1008 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
1009 			return ZFCP_ERP_FAILED;
1010 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
1011 			return ZFCP_ERP_EXIT;
1012 		return zfcp_erp_lun_strategy_open(erp_action);
1013 
1014 	case ZFCP_ERP_STEP_LUN_OPENING:
1015 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
1016 			return ZFCP_ERP_SUCCEEDED;
1017 	}
1018 	return ZFCP_ERP_FAILED;
1019 }
1020 
1021 static int zfcp_erp_strategy_check_lun(struct scsi_device *sdev, int result)
1022 {
1023 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1024 
1025 	switch (result) {
1026 	case ZFCP_ERP_SUCCEEDED :
1027 		atomic_set(&zfcp_sdev->erp_counter, 0);
1028 		zfcp_erp_lun_unblock(sdev);
1029 		break;
1030 	case ZFCP_ERP_FAILED :
1031 		atomic_inc(&zfcp_sdev->erp_counter);
1032 		if (atomic_read(&zfcp_sdev->erp_counter) > ZFCP_MAX_ERPS) {
1033 			dev_err(&zfcp_sdev->port->adapter->ccw_device->dev,
1034 				"ERP failed for LUN 0x%016Lx on "
1035 				"port 0x%016Lx\n",
1036 				(unsigned long long)zfcp_scsi_dev_lun(sdev),
1037 				(unsigned long long)zfcp_sdev->port->wwpn);
1038 			zfcp_erp_set_lun_status(sdev,
1039 						ZFCP_STATUS_COMMON_ERP_FAILED);
1040 		}
1041 		break;
1042 	}
1043 
1044 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1045 		zfcp_erp_lun_block(sdev, 0);
1046 		result = ZFCP_ERP_EXIT;
1047 	}
1048 	return result;
1049 }
1050 
1051 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1052 {
1053 	switch (result) {
1054 	case ZFCP_ERP_SUCCEEDED :
1055 		atomic_set(&port->erp_counter, 0);
1056 		zfcp_erp_port_unblock(port);
1057 		break;
1058 
1059 	case ZFCP_ERP_FAILED :
1060 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1061 			zfcp_erp_port_block(port, 0);
1062 			result = ZFCP_ERP_EXIT;
1063 		}
1064 		atomic_inc(&port->erp_counter);
1065 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1066 			dev_err(&port->adapter->ccw_device->dev,
1067 				"ERP failed for remote port 0x%016Lx\n",
1068 				(unsigned long long)port->wwpn);
1069 			zfcp_erp_set_port_status(port,
1070 					 ZFCP_STATUS_COMMON_ERP_FAILED);
1071 		}
1072 		break;
1073 	}
1074 
1075 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1076 		zfcp_erp_port_block(port, 0);
1077 		result = ZFCP_ERP_EXIT;
1078 	}
1079 	return result;
1080 }
1081 
1082 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1083 					   int result)
1084 {
1085 	switch (result) {
1086 	case ZFCP_ERP_SUCCEEDED :
1087 		atomic_set(&adapter->erp_counter, 0);
1088 		zfcp_erp_adapter_unblock(adapter);
1089 		break;
1090 
1091 	case ZFCP_ERP_FAILED :
1092 		atomic_inc(&adapter->erp_counter);
1093 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1094 			dev_err(&adapter->ccw_device->dev,
1095 				"ERP cannot recover an error "
1096 				"on the FCP device\n");
1097 			zfcp_erp_set_adapter_status(adapter,
1098 					    ZFCP_STATUS_COMMON_ERP_FAILED);
1099 		}
1100 		break;
1101 	}
1102 
1103 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1104 		zfcp_erp_adapter_block(adapter, 0);
1105 		result = ZFCP_ERP_EXIT;
1106 	}
1107 	return result;
1108 }
1109 
1110 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1111 					  int result)
1112 {
1113 	struct zfcp_adapter *adapter = erp_action->adapter;
1114 	struct zfcp_port *port = erp_action->port;
1115 	struct scsi_device *sdev = erp_action->sdev;
1116 
1117 	switch (erp_action->action) {
1118 
1119 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1120 		result = zfcp_erp_strategy_check_lun(sdev, result);
1121 		break;
1122 
1123 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1124 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1125 		result = zfcp_erp_strategy_check_port(port, result);
1126 		break;
1127 
1128 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1129 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1130 		break;
1131 	}
1132 	return result;
1133 }
1134 
1135 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1136 {
1137 	int status = atomic_read(target_status);
1138 
1139 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1140 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1141 		return 1; /* take it online */
1142 
1143 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1144 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1145 		return 1; /* take it offline */
1146 
1147 	return 0;
1148 }
1149 
1150 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1151 {
1152 	int action = act->action;
1153 	struct zfcp_adapter *adapter = act->adapter;
1154 	struct zfcp_port *port = act->port;
1155 	struct scsi_device *sdev = act->sdev;
1156 	struct zfcp_scsi_dev *zfcp_sdev;
1157 	u32 erp_status = act->status;
1158 
1159 	switch (action) {
1160 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1161 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1162 			_zfcp_erp_adapter_reopen(adapter,
1163 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1164 						 "ersscg1", NULL);
1165 			return ZFCP_ERP_EXIT;
1166 		}
1167 		break;
1168 
1169 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1170 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1171 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1172 			_zfcp_erp_port_reopen(port,
1173 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1174 					      "ersscg2", NULL);
1175 			return ZFCP_ERP_EXIT;
1176 		}
1177 		break;
1178 
1179 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1180 		zfcp_sdev = sdev_to_zfcp(sdev);
1181 		if (zfcp_erp_strat_change_det(&zfcp_sdev->status, erp_status)) {
1182 			_zfcp_erp_lun_reopen(sdev,
1183 					     ZFCP_STATUS_COMMON_ERP_FAILED,
1184 					     "ersscg3", NULL, 0);
1185 			return ZFCP_ERP_EXIT;
1186 		}
1187 		break;
1188 	}
1189 	return ret;
1190 }
1191 
1192 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1193 {
1194 	struct zfcp_adapter *adapter = erp_action->adapter;
1195 	struct zfcp_scsi_dev *zfcp_sdev;
1196 
1197 	adapter->erp_total_count--;
1198 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1199 		adapter->erp_low_mem_count--;
1200 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1201 	}
1202 
1203 	list_del(&erp_action->list);
1204 	zfcp_dbf_rec_action("eractd1", erp_action);
1205 
1206 	switch (erp_action->action) {
1207 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1208 		zfcp_sdev = sdev_to_zfcp(erp_action->sdev);
1209 		atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
1210 				  &zfcp_sdev->status);
1211 		break;
1212 
1213 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1214 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1215 		atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
1216 				  &erp_action->port->status);
1217 		break;
1218 
1219 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1220 		atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
1221 				  &erp_action->adapter->status);
1222 		break;
1223 	}
1224 }
1225 
1226 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1227 {
1228 	struct zfcp_adapter *adapter = act->adapter;
1229 	struct zfcp_port *port = act->port;
1230 	struct scsi_device *sdev = act->sdev;
1231 
1232 	switch (act->action) {
1233 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1234 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
1235 			scsi_device_put(sdev);
1236 		break;
1237 
1238 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1239 		if (result == ZFCP_ERP_SUCCEEDED)
1240 			zfcp_scsi_schedule_rport_register(port);
1241 		/* fall through */
1242 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1243 		put_device(&port->dev);
1244 		break;
1245 
1246 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1247 		if (result == ZFCP_ERP_SUCCEEDED) {
1248 			register_service_level(&adapter->service_level);
1249 			queue_work(adapter->work_queue, &adapter->scan_work);
1250 		} else
1251 			unregister_service_level(&adapter->service_level);
1252 		kref_put(&adapter->ref, zfcp_adapter_release);
1253 		break;
1254 	}
1255 }
1256 
1257 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1258 {
1259 	switch (erp_action->action) {
1260 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1261 		return zfcp_erp_adapter_strategy(erp_action);
1262 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1263 		return zfcp_erp_port_forced_strategy(erp_action);
1264 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1265 		return zfcp_erp_port_strategy(erp_action);
1266 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1267 		return zfcp_erp_lun_strategy(erp_action);
1268 	}
1269 	return ZFCP_ERP_FAILED;
1270 }
1271 
1272 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1273 {
1274 	int retval;
1275 	unsigned long flags;
1276 	struct zfcp_adapter *adapter = erp_action->adapter;
1277 
1278 	kref_get(&adapter->ref);
1279 
1280 	write_lock_irqsave(&adapter->erp_lock, flags);
1281 	zfcp_erp_strategy_check_fsfreq(erp_action);
1282 
1283 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1284 		zfcp_erp_action_dequeue(erp_action);
1285 		retval = ZFCP_ERP_DISMISSED;
1286 		goto unlock;
1287 	}
1288 
1289 	if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
1290 		retval = ZFCP_ERP_FAILED;
1291 		goto check_target;
1292 	}
1293 
1294 	zfcp_erp_action_to_running(erp_action);
1295 
1296 	/* no lock to allow for blocking operations */
1297 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1298 	retval = zfcp_erp_strategy_do_action(erp_action);
1299 	write_lock_irqsave(&adapter->erp_lock, flags);
1300 
1301 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1302 		retval = ZFCP_ERP_CONTINUES;
1303 
1304 	switch (retval) {
1305 	case ZFCP_ERP_NOMEM:
1306 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1307 			++adapter->erp_low_mem_count;
1308 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1309 		}
1310 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1311 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1", NULL);
1312 		else {
1313 			zfcp_erp_strategy_memwait(erp_action);
1314 			retval = ZFCP_ERP_CONTINUES;
1315 		}
1316 		goto unlock;
1317 
1318 	case ZFCP_ERP_CONTINUES:
1319 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1320 			--adapter->erp_low_mem_count;
1321 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1322 		}
1323 		goto unlock;
1324 	}
1325 
1326 check_target:
1327 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1328 	zfcp_erp_action_dequeue(erp_action);
1329 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1330 	if (retval == ZFCP_ERP_EXIT)
1331 		goto unlock;
1332 	if (retval == ZFCP_ERP_SUCCEEDED)
1333 		zfcp_erp_strategy_followup_success(erp_action);
1334 	if (retval == ZFCP_ERP_FAILED)
1335 		zfcp_erp_strategy_followup_failed(erp_action);
1336 
1337  unlock:
1338 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1339 
1340 	if (retval != ZFCP_ERP_CONTINUES)
1341 		zfcp_erp_action_cleanup(erp_action, retval);
1342 
1343 	kref_put(&adapter->ref, zfcp_adapter_release);
1344 	return retval;
1345 }
1346 
1347 static int zfcp_erp_thread(void *data)
1348 {
1349 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1350 	struct list_head *next;
1351 	struct zfcp_erp_action *act;
1352 	unsigned long flags;
1353 
1354 	for (;;) {
1355 		zfcp_dbf_rec_thread_lock("erthrd1", adapter->dbf);
1356 		wait_event_interruptible(adapter->erp_ready_wq,
1357 			   !list_empty(&adapter->erp_ready_head) ||
1358 			   kthread_should_stop());
1359 		zfcp_dbf_rec_thread_lock("erthrd2", adapter->dbf);
1360 
1361 		if (kthread_should_stop())
1362 			break;
1363 
1364 		write_lock_irqsave(&adapter->erp_lock, flags);
1365 		next = adapter->erp_ready_head.next;
1366 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1367 
1368 		if (next != &adapter->erp_ready_head) {
1369 			act = list_entry(next, struct zfcp_erp_action, list);
1370 
1371 			/* there is more to come after dismission, no notify */
1372 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1373 				zfcp_erp_wakeup(adapter);
1374 		}
1375 	}
1376 
1377 	return 0;
1378 }
1379 
1380 /**
1381  * zfcp_erp_thread_setup - Start ERP thread for adapter
1382  * @adapter: Adapter to start the ERP thread for
1383  *
1384  * Returns 0 on success or error code from kernel_thread()
1385  */
1386 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1387 {
1388 	struct task_struct *thread;
1389 
1390 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1391 			     dev_name(&adapter->ccw_device->dev));
1392 	if (IS_ERR(thread)) {
1393 		dev_err(&adapter->ccw_device->dev,
1394 			"Creating an ERP thread for the FCP device failed.\n");
1395 		return PTR_ERR(thread);
1396 	}
1397 
1398 	adapter->erp_thread = thread;
1399 	return 0;
1400 }
1401 
1402 /**
1403  * zfcp_erp_thread_kill - Stop ERP thread.
1404  * @adapter: Adapter where the ERP thread should be stopped.
1405  *
1406  * The caller of this routine ensures that the specified adapter has
1407  * been shut down and that this operation has been completed. Thus,
1408  * there are no pending erp_actions which would need to be handled
1409  * here.
1410  */
1411 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1412 {
1413 	kthread_stop(adapter->erp_thread);
1414 	adapter->erp_thread = NULL;
1415 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1416 	WARN_ON(!list_empty(&adapter->erp_running_head));
1417 }
1418 
1419 /**
1420  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1421  * @adapter: adapter for which to wait for completion of its error recovery
1422  */
1423 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1424 {
1425 	wait_event(adapter->erp_done_wqh,
1426 		   !(atomic_read(&adapter->status) &
1427 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1428 }
1429 
1430 /**
1431  * zfcp_erp_set_adapter_status - set adapter status bits
1432  * @adapter: adapter to change the status
1433  * @mask: status bits to change
1434  *
1435  * Changes in common status bits are propagated to attached ports and LUNs.
1436  */
1437 void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1438 {
1439 	struct zfcp_port *port;
1440 	struct scsi_device *sdev;
1441 	unsigned long flags;
1442 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1443 
1444 	atomic_set_mask(mask, &adapter->status);
1445 
1446 	if (!common_mask)
1447 		return;
1448 
1449 	read_lock_irqsave(&adapter->port_list_lock, flags);
1450 	list_for_each_entry(port, &adapter->port_list, list)
1451 		atomic_set_mask(common_mask, &port->status);
1452 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1453 
1454 	shost_for_each_device(sdev, adapter->scsi_host)
1455 		atomic_set_mask(common_mask, &sdev_to_zfcp(sdev)->status);
1456 }
1457 
1458 /**
1459  * zfcp_erp_clear_adapter_status - clear adapter status bits
1460  * @adapter: adapter to change the status
1461  * @mask: status bits to change
1462  *
1463  * Changes in common status bits are propagated to attached ports and LUNs.
1464  */
1465 void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1466 {
1467 	struct zfcp_port *port;
1468 	struct scsi_device *sdev;
1469 	unsigned long flags;
1470 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1471 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1472 
1473 	atomic_clear_mask(mask, &adapter->status);
1474 
1475 	if (!common_mask)
1476 		return;
1477 
1478 	if (clear_counter)
1479 		atomic_set(&adapter->erp_counter, 0);
1480 
1481 	read_lock_irqsave(&adapter->port_list_lock, flags);
1482 	list_for_each_entry(port, &adapter->port_list, list) {
1483 		atomic_clear_mask(common_mask, &port->status);
1484 		if (clear_counter)
1485 			atomic_set(&port->erp_counter, 0);
1486 	}
1487 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1488 
1489 	shost_for_each_device(sdev, adapter->scsi_host) {
1490 		atomic_clear_mask(common_mask, &sdev_to_zfcp(sdev)->status);
1491 		if (clear_counter)
1492 			atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1493 	}
1494 }
1495 
1496 /**
1497  * zfcp_erp_set_port_status - set port status bits
1498  * @port: port to change the status
1499  * @mask: status bits to change
1500  *
1501  * Changes in common status bits are propagated to attached LUNs.
1502  */
1503 void zfcp_erp_set_port_status(struct zfcp_port *port, u32 mask)
1504 {
1505 	struct scsi_device *sdev;
1506 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1507 
1508 	atomic_set_mask(mask, &port->status);
1509 
1510 	if (!common_mask)
1511 		return;
1512 
1513 	shost_for_each_device(sdev, port->adapter->scsi_host)
1514 		if (sdev_to_zfcp(sdev)->port == port)
1515 			atomic_set_mask(common_mask,
1516 					&sdev_to_zfcp(sdev)->status);
1517 }
1518 
1519 /**
1520  * zfcp_erp_clear_port_status - clear port status bits
1521  * @port: adapter to change the status
1522  * @mask: status bits to change
1523  *
1524  * Changes in common status bits are propagated to attached LUNs.
1525  */
1526 void zfcp_erp_clear_port_status(struct zfcp_port *port, u32 mask)
1527 {
1528 	struct scsi_device *sdev;
1529 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1530 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1531 
1532 	atomic_clear_mask(mask, &port->status);
1533 
1534 	if (!common_mask)
1535 		return;
1536 
1537 	if (clear_counter)
1538 		atomic_set(&port->erp_counter, 0);
1539 
1540 	shost_for_each_device(sdev, port->adapter->scsi_host)
1541 		if (sdev_to_zfcp(sdev)->port == port) {
1542 			atomic_clear_mask(common_mask,
1543 					  &sdev_to_zfcp(sdev)->status);
1544 			if (clear_counter)
1545 				atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1546 		}
1547 }
1548 
1549 /**
1550  * zfcp_erp_set_lun_status - set lun status bits
1551  * @sdev: SCSI device / lun to set the status bits
1552  * @mask: status bits to change
1553  */
1554 void zfcp_erp_set_lun_status(struct scsi_device *sdev, u32 mask)
1555 {
1556 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1557 
1558 	atomic_set_mask(mask, &zfcp_sdev->status);
1559 }
1560 
1561 /**
1562  * zfcp_erp_clear_lun_status - clear lun status bits
1563  * @sdev: SCSi device / lun to clear the status bits
1564  * @mask: status bits to change
1565  */
1566 void zfcp_erp_clear_lun_status(struct scsi_device *sdev, u32 mask)
1567 {
1568 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1569 
1570 	atomic_clear_mask(mask, &zfcp_sdev->status);
1571 
1572 	if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1573 		atomic_set(&zfcp_sdev->erp_counter, 0);
1574 }
1575 
1576