xref: /openbmc/linux/drivers/s390/scsi/zfcp_erp.c (revision 8ee90c5c)
1 /*
2  * zfcp device driver
3  *
4  * Error Recovery Procedures (ERP).
5  *
6  * Copyright IBM Corp. 2002, 2016
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_run("erardy1", act);
80 	wake_up(&adapter->erp_ready_wq);
81 	zfcp_dbf_rec_run("erardy2", act);
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 		spin_lock(port->adapter->scsi_host->host_lock);
107 		__shost_for_each_device(sdev, port->adapter->scsi_host)
108 			if (sdev_to_zfcp(sdev)->port == port)
109 				zfcp_erp_action_dismiss_lun(sdev);
110 		spin_unlock(port->adapter->scsi_host->host_lock);
111 	}
112 }
113 
114 static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *adapter)
115 {
116 	struct zfcp_port *port;
117 
118 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
119 		zfcp_erp_action_dismiss(&adapter->erp_action);
120 	else {
121 		read_lock(&adapter->port_list_lock);
122 		list_for_each_entry(port, &adapter->port_list, list)
123 		    zfcp_erp_action_dismiss_port(port);
124 		read_unlock(&adapter->port_list_lock);
125 	}
126 }
127 
128 static int zfcp_erp_required_act(int want, struct zfcp_adapter *adapter,
129 				 struct zfcp_port *port,
130 				 struct scsi_device *sdev)
131 {
132 	int need = want;
133 	int l_status, p_status, a_status;
134 	struct zfcp_scsi_dev *zfcp_sdev;
135 
136 	switch (want) {
137 	case ZFCP_ERP_ACTION_REOPEN_LUN:
138 		zfcp_sdev = sdev_to_zfcp(sdev);
139 		l_status = atomic_read(&zfcp_sdev->status);
140 		if (l_status & ZFCP_STATUS_COMMON_ERP_INUSE)
141 			return 0;
142 		p_status = atomic_read(&port->status);
143 		if (!(p_status & ZFCP_STATUS_COMMON_RUNNING) ||
144 		      p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
145 			return 0;
146 		if (!(p_status & ZFCP_STATUS_COMMON_UNBLOCKED))
147 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
148 		/* fall through */
149 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
150 		p_status = atomic_read(&port->status);
151 		if (!(p_status & ZFCP_STATUS_COMMON_OPEN))
152 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
153 		/* fall through */
154 	case ZFCP_ERP_ACTION_REOPEN_PORT:
155 		p_status = atomic_read(&port->status);
156 		if (p_status & ZFCP_STATUS_COMMON_ERP_INUSE)
157 			return 0;
158 		a_status = atomic_read(&adapter->status);
159 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) ||
160 		      a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
161 			return 0;
162 		if (p_status & ZFCP_STATUS_COMMON_NOESC)
163 			return need;
164 		if (!(a_status & ZFCP_STATUS_COMMON_UNBLOCKED))
165 			need = ZFCP_ERP_ACTION_REOPEN_ADAPTER;
166 		/* fall through */
167 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
168 		a_status = atomic_read(&adapter->status);
169 		if (a_status & ZFCP_STATUS_COMMON_ERP_INUSE)
170 			return 0;
171 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) &&
172 		    !(a_status & ZFCP_STATUS_COMMON_OPEN))
173 			return 0; /* shutdown requested for closed adapter */
174 	}
175 
176 	return need;
177 }
178 
179 static struct zfcp_erp_action *zfcp_erp_setup_act(int need, u32 act_status,
180 						  struct zfcp_adapter *adapter,
181 						  struct zfcp_port *port,
182 						  struct scsi_device *sdev)
183 {
184 	struct zfcp_erp_action *erp_action;
185 	struct zfcp_scsi_dev *zfcp_sdev;
186 
187 	switch (need) {
188 	case ZFCP_ERP_ACTION_REOPEN_LUN:
189 		zfcp_sdev = sdev_to_zfcp(sdev);
190 		if (!(act_status & ZFCP_STATUS_ERP_NO_REF))
191 			if (scsi_device_get(sdev))
192 				return NULL;
193 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE,
194 				&zfcp_sdev->status);
195 		erp_action = &zfcp_sdev->erp_action;
196 		WARN_ON_ONCE(erp_action->port != port);
197 		WARN_ON_ONCE(erp_action->sdev != sdev);
198 		if (!(atomic_read(&zfcp_sdev->status) &
199 		      ZFCP_STATUS_COMMON_RUNNING))
200 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
201 		break;
202 
203 	case ZFCP_ERP_ACTION_REOPEN_PORT:
204 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
205 		if (!get_device(&port->dev))
206 			return NULL;
207 		zfcp_erp_action_dismiss_port(port);
208 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
209 		erp_action = &port->erp_action;
210 		WARN_ON_ONCE(erp_action->port != port);
211 		WARN_ON_ONCE(erp_action->sdev != NULL);
212 		if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_RUNNING))
213 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
214 		break;
215 
216 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
217 		kref_get(&adapter->ref);
218 		zfcp_erp_action_dismiss_adapter(adapter);
219 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
220 		erp_action = &adapter->erp_action;
221 		WARN_ON_ONCE(erp_action->port != NULL);
222 		WARN_ON_ONCE(erp_action->sdev != NULL);
223 		if (!(atomic_read(&adapter->status) &
224 		      ZFCP_STATUS_COMMON_RUNNING))
225 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
226 		break;
227 
228 	default:
229 		return NULL;
230 	}
231 
232 	WARN_ON_ONCE(erp_action->adapter != adapter);
233 	memset(&erp_action->list, 0, sizeof(erp_action->list));
234 	memset(&erp_action->timer, 0, sizeof(erp_action->timer));
235 	erp_action->step = ZFCP_ERP_STEP_UNINITIALIZED;
236 	erp_action->fsf_req_id = 0;
237 	erp_action->action = need;
238 	erp_action->status = act_status;
239 
240 	return erp_action;
241 }
242 
243 static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
244 				   struct zfcp_port *port,
245 				   struct scsi_device *sdev,
246 				   char *id, u32 act_status)
247 {
248 	int retval = 1, need;
249 	struct zfcp_erp_action *act;
250 
251 	if (!adapter->erp_thread)
252 		return -EIO;
253 
254 	need = zfcp_erp_required_act(want, adapter, port, sdev);
255 	if (!need)
256 		goto out;
257 
258 	act = zfcp_erp_setup_act(need, act_status, adapter, port, sdev);
259 	if (!act)
260 		goto out;
261 	atomic_or(ZFCP_STATUS_ADAPTER_ERP_PENDING, &adapter->status);
262 	++adapter->erp_total_count;
263 	list_add_tail(&act->list, &adapter->erp_ready_head);
264 	wake_up(&adapter->erp_ready_wq);
265 	retval = 0;
266  out:
267 	zfcp_dbf_rec_trig(id, adapter, port, sdev, want, need);
268 	return retval;
269 }
270 
271 static int _zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter,
272 				    int clear_mask, char *id)
273 {
274 	zfcp_erp_adapter_block(adapter, clear_mask);
275 	zfcp_scsi_schedule_rports_block(adapter);
276 
277 	/* ensure propagation of failed status to new devices */
278 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
279 		zfcp_erp_set_adapter_status(adapter,
280 					    ZFCP_STATUS_COMMON_ERP_FAILED);
281 		return -EIO;
282 	}
283 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER,
284 				       adapter, NULL, NULL, id, 0);
285 }
286 
287 /**
288  * zfcp_erp_adapter_reopen - Reopen adapter.
289  * @adapter: Adapter to reopen.
290  * @clear: Status flags to clear.
291  * @id: Id for debug trace event.
292  */
293 void zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter, int clear, char *id)
294 {
295 	unsigned long flags;
296 
297 	zfcp_erp_adapter_block(adapter, clear);
298 	zfcp_scsi_schedule_rports_block(adapter);
299 
300 	write_lock_irqsave(&adapter->erp_lock, flags);
301 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
302 		zfcp_erp_set_adapter_status(adapter,
303 					    ZFCP_STATUS_COMMON_ERP_FAILED);
304 	else
305 		zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER, adapter,
306 					NULL, NULL, id, 0);
307 	write_unlock_irqrestore(&adapter->erp_lock, flags);
308 }
309 
310 /**
311  * zfcp_erp_adapter_shutdown - Shutdown adapter.
312  * @adapter: Adapter to shut down.
313  * @clear: Status flags to clear.
314  * @id: Id for debug trace event.
315  */
316 void zfcp_erp_adapter_shutdown(struct zfcp_adapter *adapter, int clear,
317 			       char *id)
318 {
319 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
320 	zfcp_erp_adapter_reopen(adapter, clear | flags, id);
321 }
322 
323 /**
324  * zfcp_erp_port_shutdown - Shutdown port
325  * @port: Port to shut down.
326  * @clear: Status flags to clear.
327  * @id: Id for debug trace event.
328  */
329 void zfcp_erp_port_shutdown(struct zfcp_port *port, int clear, char *id)
330 {
331 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
332 	zfcp_erp_port_reopen(port, clear | flags, id);
333 }
334 
335 static void zfcp_erp_port_block(struct zfcp_port *port, int clear)
336 {
337 	zfcp_erp_clear_port_status(port,
338 				    ZFCP_STATUS_COMMON_UNBLOCKED | clear);
339 }
340 
341 static void _zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear,
342 					 char *id)
343 {
344 	zfcp_erp_port_block(port, clear);
345 	zfcp_scsi_schedule_rport_block(port);
346 
347 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
348 		return;
349 
350 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
351 				port->adapter, port, NULL, id, 0);
352 }
353 
354 /**
355  * zfcp_erp_port_forced_reopen - Forced close of port and open again
356  * @port: Port to force close and to reopen.
357  * @clear: Status flags to clear.
358  * @id: Id for debug trace event.
359  */
360 void zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear, char *id)
361 {
362 	unsigned long flags;
363 	struct zfcp_adapter *adapter = port->adapter;
364 
365 	write_lock_irqsave(&adapter->erp_lock, flags);
366 	_zfcp_erp_port_forced_reopen(port, clear, id);
367 	write_unlock_irqrestore(&adapter->erp_lock, flags);
368 }
369 
370 static int _zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id)
371 {
372 	zfcp_erp_port_block(port, clear);
373 	zfcp_scsi_schedule_rport_block(port);
374 
375 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
376 		/* ensure propagation of failed status to new devices */
377 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
378 		return -EIO;
379 	}
380 
381 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT,
382 				       port->adapter, port, NULL, id, 0);
383 }
384 
385 /**
386  * zfcp_erp_port_reopen - trigger remote port recovery
387  * @port: port to recover
388  * @clear_mask: flags in port status to be cleared
389  * @id: Id for debug trace event.
390  *
391  * Returns 0 if recovery has been triggered, < 0 if not.
392  */
393 int zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id)
394 {
395 	int retval;
396 	unsigned long flags;
397 	struct zfcp_adapter *adapter = port->adapter;
398 
399 	write_lock_irqsave(&adapter->erp_lock, flags);
400 	retval = _zfcp_erp_port_reopen(port, clear, id);
401 	write_unlock_irqrestore(&adapter->erp_lock, flags);
402 
403 	return retval;
404 }
405 
406 static void zfcp_erp_lun_block(struct scsi_device *sdev, int clear_mask)
407 {
408 	zfcp_erp_clear_lun_status(sdev,
409 				  ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask);
410 }
411 
412 static void _zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id,
413 				 u32 act_status)
414 {
415 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
416 	struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
417 
418 	zfcp_erp_lun_block(sdev, clear);
419 
420 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
421 		return;
422 
423 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_LUN, adapter,
424 				zfcp_sdev->port, sdev, id, act_status);
425 }
426 
427 /**
428  * zfcp_erp_lun_reopen - initiate reopen of a LUN
429  * @sdev: SCSI device / LUN to be reopened
430  * @clear_mask: specifies flags in LUN status to be cleared
431  * @id: Id for debug trace event.
432  *
433  * Return: 0 on success, < 0 on error
434  */
435 void zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id)
436 {
437 	unsigned long flags;
438 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
439 	struct zfcp_port *port = zfcp_sdev->port;
440 	struct zfcp_adapter *adapter = port->adapter;
441 
442 	write_lock_irqsave(&adapter->erp_lock, flags);
443 	_zfcp_erp_lun_reopen(sdev, clear, id, 0);
444 	write_unlock_irqrestore(&adapter->erp_lock, flags);
445 }
446 
447 /**
448  * zfcp_erp_lun_shutdown - Shutdown LUN
449  * @sdev: SCSI device / LUN to shut down.
450  * @clear: Status flags to clear.
451  * @id: Id for debug trace event.
452  */
453 void zfcp_erp_lun_shutdown(struct scsi_device *sdev, int clear, char *id)
454 {
455 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
456 	zfcp_erp_lun_reopen(sdev, clear | flags, id);
457 }
458 
459 /**
460  * zfcp_erp_lun_shutdown_wait - Shutdown LUN and wait for erp completion
461  * @sdev: SCSI device / LUN to shut down.
462  * @id: Id for debug trace event.
463  *
464  * Do not acquire a reference for the LUN when creating the ERP
465  * action. It is safe, because this function waits for the ERP to
466  * complete first. This allows to shutdown the LUN, even when the SCSI
467  * device is in the state SDEV_DEL when scsi_device_get will fail.
468  */
469 void zfcp_erp_lun_shutdown_wait(struct scsi_device *sdev, char *id)
470 {
471 	unsigned long flags;
472 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
473 	struct zfcp_port *port = zfcp_sdev->port;
474 	struct zfcp_adapter *adapter = port->adapter;
475 	int clear = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
476 
477 	write_lock_irqsave(&adapter->erp_lock, flags);
478 	_zfcp_erp_lun_reopen(sdev, clear, id, ZFCP_STATUS_ERP_NO_REF);
479 	write_unlock_irqrestore(&adapter->erp_lock, flags);
480 
481 	zfcp_erp_wait(adapter);
482 }
483 
484 static int status_change_set(unsigned long mask, atomic_t *status)
485 {
486 	return (atomic_read(status) ^ mask) & mask;
487 }
488 
489 static void zfcp_erp_adapter_unblock(struct zfcp_adapter *adapter)
490 {
491 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status))
492 		zfcp_dbf_rec_run("eraubl1", &adapter->erp_action);
493 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status);
494 }
495 
496 static void zfcp_erp_port_unblock(struct zfcp_port *port)
497 {
498 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status))
499 		zfcp_dbf_rec_run("erpubl1", &port->erp_action);
500 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status);
501 }
502 
503 static void zfcp_erp_lun_unblock(struct scsi_device *sdev)
504 {
505 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
506 
507 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status))
508 		zfcp_dbf_rec_run("erlubl1", &sdev_to_zfcp(sdev)->erp_action);
509 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status);
510 }
511 
512 static void zfcp_erp_action_to_running(struct zfcp_erp_action *erp_action)
513 {
514 	list_move(&erp_action->list, &erp_action->adapter->erp_running_head);
515 	zfcp_dbf_rec_run("erator1", erp_action);
516 }
517 
518 static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
519 {
520 	struct zfcp_adapter *adapter = act->adapter;
521 	struct zfcp_fsf_req *req;
522 
523 	if (!act->fsf_req_id)
524 		return;
525 
526 	spin_lock(&adapter->req_list->lock);
527 	req = _zfcp_reqlist_find(adapter->req_list, act->fsf_req_id);
528 	if (req && req->erp_action == act) {
529 		if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
530 				   ZFCP_STATUS_ERP_TIMEDOUT)) {
531 			req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
532 			zfcp_dbf_rec_run("erscf_1", act);
533 			req->erp_action = NULL;
534 		}
535 		if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
536 			zfcp_dbf_rec_run("erscf_2", act);
537 		if (req->status & ZFCP_STATUS_FSFREQ_DISMISSED)
538 			act->fsf_req_id = 0;
539 	} else
540 		act->fsf_req_id = 0;
541 	spin_unlock(&adapter->req_list->lock);
542 }
543 
544 /**
545  * zfcp_erp_notify - Trigger ERP action.
546  * @erp_action: ERP action to continue.
547  * @set_mask: ERP action status flags to set.
548  */
549 void zfcp_erp_notify(struct zfcp_erp_action *erp_action, unsigned long set_mask)
550 {
551 	struct zfcp_adapter *adapter = erp_action->adapter;
552 	unsigned long flags;
553 
554 	write_lock_irqsave(&adapter->erp_lock, flags);
555 	if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING) {
556 		erp_action->status |= set_mask;
557 		zfcp_erp_action_ready(erp_action);
558 	}
559 	write_unlock_irqrestore(&adapter->erp_lock, flags);
560 }
561 
562 /**
563  * zfcp_erp_timeout_handler - Trigger ERP action from timed out ERP request
564  * @data: ERP action (from timer data)
565  */
566 void zfcp_erp_timeout_handler(unsigned long data)
567 {
568 	struct zfcp_erp_action *act = (struct zfcp_erp_action *) data;
569 	zfcp_erp_notify(act, ZFCP_STATUS_ERP_TIMEDOUT);
570 }
571 
572 static void zfcp_erp_memwait_handler(unsigned long data)
573 {
574 	zfcp_erp_notify((struct zfcp_erp_action *)data, 0);
575 }
576 
577 static void zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
578 {
579 	setup_timer(&erp_action->timer, zfcp_erp_memwait_handler,
580 		    (unsigned long) erp_action);
581 	erp_action->timer.expires = jiffies + HZ;
582 	add_timer(&erp_action->timer);
583 }
584 
585 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
586 				      int clear, char *id)
587 {
588 	struct zfcp_port *port;
589 
590 	read_lock(&adapter->port_list_lock);
591 	list_for_each_entry(port, &adapter->port_list, list)
592 		_zfcp_erp_port_reopen(port, clear, id);
593 	read_unlock(&adapter->port_list_lock);
594 }
595 
596 static void _zfcp_erp_lun_reopen_all(struct zfcp_port *port, int clear,
597 				     char *id)
598 {
599 	struct scsi_device *sdev;
600 
601 	spin_lock(port->adapter->scsi_host->host_lock);
602 	__shost_for_each_device(sdev, port->adapter->scsi_host)
603 		if (sdev_to_zfcp(sdev)->port == port)
604 			_zfcp_erp_lun_reopen(sdev, clear, id, 0);
605 	spin_unlock(port->adapter->scsi_host->host_lock);
606 }
607 
608 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
609 {
610 	switch (act->action) {
611 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
612 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1");
613 		break;
614 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
615 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2");
616 		break;
617 	case ZFCP_ERP_ACTION_REOPEN_PORT:
618 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3");
619 		break;
620 	case ZFCP_ERP_ACTION_REOPEN_LUN:
621 		_zfcp_erp_lun_reopen(act->sdev, 0, "ersff_4", 0);
622 		break;
623 	}
624 }
625 
626 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
627 {
628 	switch (act->action) {
629 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
630 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1");
631 		break;
632 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
633 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2");
634 		break;
635 	case ZFCP_ERP_ACTION_REOPEN_PORT:
636 		_zfcp_erp_lun_reopen_all(act->port, 0, "ersfs_3");
637 		break;
638 	}
639 }
640 
641 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
642 {
643 	unsigned long flags;
644 
645 	read_lock_irqsave(&adapter->erp_lock, flags);
646 	if (list_empty(&adapter->erp_ready_head) &&
647 	    list_empty(&adapter->erp_running_head)) {
648 			atomic_andnot(ZFCP_STATUS_ADAPTER_ERP_PENDING,
649 					  &adapter->status);
650 			wake_up(&adapter->erp_done_wqh);
651 	}
652 	read_unlock_irqrestore(&adapter->erp_lock, flags);
653 }
654 
655 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
656 {
657 	struct zfcp_port *port;
658 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
659 				 adapter->peer_d_id);
660 	if (IS_ERR(port)) /* error or port already attached */
661 		return;
662 	_zfcp_erp_port_reopen(port, 0, "ereptp1");
663 }
664 
665 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
666 {
667 	int retries;
668 	int sleep = 1;
669 	struct zfcp_adapter *adapter = erp_action->adapter;
670 
671 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
672 
673 	for (retries = 7; retries; retries--) {
674 		atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
675 				  &adapter->status);
676 		write_lock_irq(&adapter->erp_lock);
677 		zfcp_erp_action_to_running(erp_action);
678 		write_unlock_irq(&adapter->erp_lock);
679 		if (zfcp_fsf_exchange_config_data(erp_action)) {
680 			atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
681 					  &adapter->status);
682 			return ZFCP_ERP_FAILED;
683 		}
684 
685 		wait_event(adapter->erp_ready_wq,
686 			   !list_empty(&adapter->erp_ready_head));
687 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
688 			break;
689 
690 		if (!(atomic_read(&adapter->status) &
691 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
692 			break;
693 
694 		ssleep(sleep);
695 		sleep *= 2;
696 	}
697 
698 	atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
699 			  &adapter->status);
700 
701 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
702 		return ZFCP_ERP_FAILED;
703 
704 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
705 		zfcp_erp_enqueue_ptp_port(adapter);
706 
707 	return ZFCP_ERP_SUCCEEDED;
708 }
709 
710 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
711 {
712 	int ret;
713 	struct zfcp_adapter *adapter = act->adapter;
714 
715 	write_lock_irq(&adapter->erp_lock);
716 	zfcp_erp_action_to_running(act);
717 	write_unlock_irq(&adapter->erp_lock);
718 
719 	ret = zfcp_fsf_exchange_port_data(act);
720 	if (ret == -EOPNOTSUPP)
721 		return ZFCP_ERP_SUCCEEDED;
722 	if (ret)
723 		return ZFCP_ERP_FAILED;
724 
725 	zfcp_dbf_rec_run("erasox1", act);
726 	wait_event(adapter->erp_ready_wq,
727 		   !list_empty(&adapter->erp_ready_head));
728 	zfcp_dbf_rec_run("erasox2", act);
729 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
730 		return ZFCP_ERP_FAILED;
731 
732 	return ZFCP_ERP_SUCCEEDED;
733 }
734 
735 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
736 {
737 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
738 		return ZFCP_ERP_FAILED;
739 
740 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
741 		return ZFCP_ERP_FAILED;
742 
743 	if (mempool_resize(act->adapter->pool.sr_data,
744 			   act->adapter->stat_read_buf_num))
745 		return ZFCP_ERP_FAILED;
746 
747 	if (mempool_resize(act->adapter->pool.status_read_req,
748 			   act->adapter->stat_read_buf_num))
749 		return ZFCP_ERP_FAILED;
750 
751 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
752 	if (zfcp_status_read_refill(act->adapter))
753 		return ZFCP_ERP_FAILED;
754 
755 	return ZFCP_ERP_SUCCEEDED;
756 }
757 
758 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
759 {
760 	struct zfcp_adapter *adapter = act->adapter;
761 
762 	/* close queues to ensure that buffers are not accessed by adapter */
763 	zfcp_qdio_close(adapter->qdio);
764 	zfcp_fsf_req_dismiss_all(adapter);
765 	adapter->fsf_req_seq_no = 0;
766 	zfcp_fc_wka_ports_force_offline(adapter->gs);
767 	/* all ports and LUNs are closed */
768 	zfcp_erp_clear_adapter_status(adapter, ZFCP_STATUS_COMMON_OPEN);
769 
770 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
771 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
772 }
773 
774 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
775 {
776 	struct zfcp_adapter *adapter = act->adapter;
777 
778 	if (zfcp_qdio_open(adapter->qdio)) {
779 		atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
780 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
781 				  &adapter->status);
782 		return ZFCP_ERP_FAILED;
783 	}
784 
785 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
786 		zfcp_erp_adapter_strategy_close(act);
787 		return ZFCP_ERP_FAILED;
788 	}
789 
790 	atomic_or(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
791 
792 	return ZFCP_ERP_SUCCEEDED;
793 }
794 
795 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
796 {
797 	struct zfcp_adapter *adapter = act->adapter;
798 
799 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
800 		zfcp_erp_adapter_strategy_close(act);
801 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
802 			return ZFCP_ERP_EXIT;
803 	}
804 
805 	if (zfcp_erp_adapter_strategy_open(act)) {
806 		ssleep(8);
807 		return ZFCP_ERP_FAILED;
808 	}
809 
810 	return ZFCP_ERP_SUCCEEDED;
811 }
812 
813 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
814 {
815 	int retval;
816 
817 	retval = zfcp_fsf_close_physical_port(act);
818 	if (retval == -ENOMEM)
819 		return ZFCP_ERP_NOMEM;
820 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
821 	if (retval)
822 		return ZFCP_ERP_FAILED;
823 
824 	return ZFCP_ERP_CONTINUES;
825 }
826 
827 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
828 {
829 	struct zfcp_port *port = erp_action->port;
830 	int status = atomic_read(&port->status);
831 
832 	switch (erp_action->step) {
833 	case ZFCP_ERP_STEP_UNINITIALIZED:
834 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
835 		    (status & ZFCP_STATUS_COMMON_OPEN))
836 			return zfcp_erp_port_forced_strategy_close(erp_action);
837 		else
838 			return ZFCP_ERP_FAILED;
839 
840 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
841 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
842 			return ZFCP_ERP_SUCCEEDED;
843 	}
844 	return ZFCP_ERP_FAILED;
845 }
846 
847 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
848 {
849 	int retval;
850 
851 	retval = zfcp_fsf_close_port(erp_action);
852 	if (retval == -ENOMEM)
853 		return ZFCP_ERP_NOMEM;
854 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
855 	if (retval)
856 		return ZFCP_ERP_FAILED;
857 	return ZFCP_ERP_CONTINUES;
858 }
859 
860 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
861 {
862 	int retval;
863 
864 	retval = zfcp_fsf_open_port(erp_action);
865 	if (retval == -ENOMEM)
866 		return ZFCP_ERP_NOMEM;
867 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
868 	if (retval)
869 		return ZFCP_ERP_FAILED;
870 	return ZFCP_ERP_CONTINUES;
871 }
872 
873 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
874 {
875 	struct zfcp_adapter *adapter = act->adapter;
876 	struct zfcp_port *port = act->port;
877 
878 	if (port->wwpn != adapter->peer_wwpn) {
879 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
880 		return ZFCP_ERP_FAILED;
881 	}
882 	port->d_id = adapter->peer_d_id;
883 	return zfcp_erp_port_strategy_open_port(act);
884 }
885 
886 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
887 {
888 	struct zfcp_adapter *adapter = act->adapter;
889 	struct zfcp_port *port = act->port;
890 	int p_status = atomic_read(&port->status);
891 
892 	switch (act->step) {
893 	case ZFCP_ERP_STEP_UNINITIALIZED:
894 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
895 	case ZFCP_ERP_STEP_PORT_CLOSING:
896 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
897 			return zfcp_erp_open_ptp_port(act);
898 		if (!port->d_id) {
899 			zfcp_fc_trigger_did_lookup(port);
900 			return ZFCP_ERP_EXIT;
901 		}
902 		return zfcp_erp_port_strategy_open_port(act);
903 
904 	case ZFCP_ERP_STEP_PORT_OPENING:
905 		/* D_ID might have changed during open */
906 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
907 			if (!port->d_id) {
908 				zfcp_fc_trigger_did_lookup(port);
909 				return ZFCP_ERP_EXIT;
910 			}
911 			return ZFCP_ERP_SUCCEEDED;
912 		}
913 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
914 			port->d_id = 0;
915 			return ZFCP_ERP_FAILED;
916 		}
917 		/* fall through otherwise */
918 	}
919 	return ZFCP_ERP_FAILED;
920 }
921 
922 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
923 {
924 	struct zfcp_port *port = erp_action->port;
925 	int p_status = atomic_read(&port->status);
926 
927 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
928 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
929 		goto close_init_done;
930 
931 	switch (erp_action->step) {
932 	case ZFCP_ERP_STEP_UNINITIALIZED:
933 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
934 			return zfcp_erp_port_strategy_close(erp_action);
935 		break;
936 
937 	case ZFCP_ERP_STEP_PORT_CLOSING:
938 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
939 			return ZFCP_ERP_FAILED;
940 		break;
941 	}
942 
943 close_init_done:
944 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
945 		return ZFCP_ERP_EXIT;
946 
947 	return zfcp_erp_port_strategy_open_common(erp_action);
948 }
949 
950 static void zfcp_erp_lun_strategy_clearstati(struct scsi_device *sdev)
951 {
952 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
953 
954 	atomic_andnot(ZFCP_STATUS_COMMON_ACCESS_DENIED,
955 			  &zfcp_sdev->status);
956 }
957 
958 static int zfcp_erp_lun_strategy_close(struct zfcp_erp_action *erp_action)
959 {
960 	int retval = zfcp_fsf_close_lun(erp_action);
961 	if (retval == -ENOMEM)
962 		return ZFCP_ERP_NOMEM;
963 	erp_action->step = ZFCP_ERP_STEP_LUN_CLOSING;
964 	if (retval)
965 		return ZFCP_ERP_FAILED;
966 	return ZFCP_ERP_CONTINUES;
967 }
968 
969 static int zfcp_erp_lun_strategy_open(struct zfcp_erp_action *erp_action)
970 {
971 	int retval = zfcp_fsf_open_lun(erp_action);
972 	if (retval == -ENOMEM)
973 		return ZFCP_ERP_NOMEM;
974 	erp_action->step = ZFCP_ERP_STEP_LUN_OPENING;
975 	if (retval)
976 		return  ZFCP_ERP_FAILED;
977 	return ZFCP_ERP_CONTINUES;
978 }
979 
980 static int zfcp_erp_lun_strategy(struct zfcp_erp_action *erp_action)
981 {
982 	struct scsi_device *sdev = erp_action->sdev;
983 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
984 
985 	switch (erp_action->step) {
986 	case ZFCP_ERP_STEP_UNINITIALIZED:
987 		zfcp_erp_lun_strategy_clearstati(sdev);
988 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
989 			return zfcp_erp_lun_strategy_close(erp_action);
990 		/* already closed, fall through */
991 	case ZFCP_ERP_STEP_LUN_CLOSING:
992 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
993 			return ZFCP_ERP_FAILED;
994 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
995 			return ZFCP_ERP_EXIT;
996 		return zfcp_erp_lun_strategy_open(erp_action);
997 
998 	case ZFCP_ERP_STEP_LUN_OPENING:
999 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
1000 			return ZFCP_ERP_SUCCEEDED;
1001 	}
1002 	return ZFCP_ERP_FAILED;
1003 }
1004 
1005 static int zfcp_erp_strategy_check_lun(struct scsi_device *sdev, int result)
1006 {
1007 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1008 
1009 	switch (result) {
1010 	case ZFCP_ERP_SUCCEEDED :
1011 		atomic_set(&zfcp_sdev->erp_counter, 0);
1012 		zfcp_erp_lun_unblock(sdev);
1013 		break;
1014 	case ZFCP_ERP_FAILED :
1015 		atomic_inc(&zfcp_sdev->erp_counter);
1016 		if (atomic_read(&zfcp_sdev->erp_counter) > ZFCP_MAX_ERPS) {
1017 			dev_err(&zfcp_sdev->port->adapter->ccw_device->dev,
1018 				"ERP failed for LUN 0x%016Lx on "
1019 				"port 0x%016Lx\n",
1020 				(unsigned long long)zfcp_scsi_dev_lun(sdev),
1021 				(unsigned long long)zfcp_sdev->port->wwpn);
1022 			zfcp_erp_set_lun_status(sdev,
1023 						ZFCP_STATUS_COMMON_ERP_FAILED);
1024 		}
1025 		break;
1026 	}
1027 
1028 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1029 		zfcp_erp_lun_block(sdev, 0);
1030 		result = ZFCP_ERP_EXIT;
1031 	}
1032 	return result;
1033 }
1034 
1035 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1036 {
1037 	switch (result) {
1038 	case ZFCP_ERP_SUCCEEDED :
1039 		atomic_set(&port->erp_counter, 0);
1040 		zfcp_erp_port_unblock(port);
1041 		break;
1042 
1043 	case ZFCP_ERP_FAILED :
1044 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1045 			zfcp_erp_port_block(port, 0);
1046 			result = ZFCP_ERP_EXIT;
1047 		}
1048 		atomic_inc(&port->erp_counter);
1049 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1050 			dev_err(&port->adapter->ccw_device->dev,
1051 				"ERP failed for remote port 0x%016Lx\n",
1052 				(unsigned long long)port->wwpn);
1053 			zfcp_erp_set_port_status(port,
1054 					 ZFCP_STATUS_COMMON_ERP_FAILED);
1055 		}
1056 		break;
1057 	}
1058 
1059 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1060 		zfcp_erp_port_block(port, 0);
1061 		result = ZFCP_ERP_EXIT;
1062 	}
1063 	return result;
1064 }
1065 
1066 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1067 					   int result)
1068 {
1069 	switch (result) {
1070 	case ZFCP_ERP_SUCCEEDED :
1071 		atomic_set(&adapter->erp_counter, 0);
1072 		zfcp_erp_adapter_unblock(adapter);
1073 		break;
1074 
1075 	case ZFCP_ERP_FAILED :
1076 		atomic_inc(&adapter->erp_counter);
1077 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1078 			dev_err(&adapter->ccw_device->dev,
1079 				"ERP cannot recover an error "
1080 				"on the FCP device\n");
1081 			zfcp_erp_set_adapter_status(adapter,
1082 					    ZFCP_STATUS_COMMON_ERP_FAILED);
1083 		}
1084 		break;
1085 	}
1086 
1087 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1088 		zfcp_erp_adapter_block(adapter, 0);
1089 		result = ZFCP_ERP_EXIT;
1090 	}
1091 	return result;
1092 }
1093 
1094 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1095 					  int result)
1096 {
1097 	struct zfcp_adapter *adapter = erp_action->adapter;
1098 	struct zfcp_port *port = erp_action->port;
1099 	struct scsi_device *sdev = erp_action->sdev;
1100 
1101 	switch (erp_action->action) {
1102 
1103 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1104 		result = zfcp_erp_strategy_check_lun(sdev, result);
1105 		break;
1106 
1107 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1108 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1109 		result = zfcp_erp_strategy_check_port(port, result);
1110 		break;
1111 
1112 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1113 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1114 		break;
1115 	}
1116 	return result;
1117 }
1118 
1119 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1120 {
1121 	int status = atomic_read(target_status);
1122 
1123 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1124 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1125 		return 1; /* take it online */
1126 
1127 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1128 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1129 		return 1; /* take it offline */
1130 
1131 	return 0;
1132 }
1133 
1134 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1135 {
1136 	int action = act->action;
1137 	struct zfcp_adapter *adapter = act->adapter;
1138 	struct zfcp_port *port = act->port;
1139 	struct scsi_device *sdev = act->sdev;
1140 	struct zfcp_scsi_dev *zfcp_sdev;
1141 	u32 erp_status = act->status;
1142 
1143 	switch (action) {
1144 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1145 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1146 			_zfcp_erp_adapter_reopen(adapter,
1147 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1148 						 "ersscg1");
1149 			return ZFCP_ERP_EXIT;
1150 		}
1151 		break;
1152 
1153 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1154 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1155 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1156 			_zfcp_erp_port_reopen(port,
1157 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1158 					      "ersscg2");
1159 			return ZFCP_ERP_EXIT;
1160 		}
1161 		break;
1162 
1163 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1164 		zfcp_sdev = sdev_to_zfcp(sdev);
1165 		if (zfcp_erp_strat_change_det(&zfcp_sdev->status, erp_status)) {
1166 			_zfcp_erp_lun_reopen(sdev,
1167 					     ZFCP_STATUS_COMMON_ERP_FAILED,
1168 					     "ersscg3", 0);
1169 			return ZFCP_ERP_EXIT;
1170 		}
1171 		break;
1172 	}
1173 	return ret;
1174 }
1175 
1176 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1177 {
1178 	struct zfcp_adapter *adapter = erp_action->adapter;
1179 	struct zfcp_scsi_dev *zfcp_sdev;
1180 
1181 	adapter->erp_total_count--;
1182 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1183 		adapter->erp_low_mem_count--;
1184 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1185 	}
1186 
1187 	list_del(&erp_action->list);
1188 	zfcp_dbf_rec_run("eractd1", erp_action);
1189 
1190 	switch (erp_action->action) {
1191 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1192 		zfcp_sdev = sdev_to_zfcp(erp_action->sdev);
1193 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1194 				  &zfcp_sdev->status);
1195 		break;
1196 
1197 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1198 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1199 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1200 				  &erp_action->port->status);
1201 		break;
1202 
1203 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1204 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1205 				  &erp_action->adapter->status);
1206 		break;
1207 	}
1208 }
1209 
1210 /**
1211  * zfcp_erp_try_rport_unblock - unblock rport if no more/new recovery
1212  * @port: zfcp_port whose fc_rport we should try to unblock
1213  */
1214 static void zfcp_erp_try_rport_unblock(struct zfcp_port *port)
1215 {
1216 	unsigned long flags;
1217 	struct zfcp_adapter *adapter = port->adapter;
1218 	int port_status;
1219 	struct Scsi_Host *shost = adapter->scsi_host;
1220 	struct scsi_device *sdev;
1221 
1222 	write_lock_irqsave(&adapter->erp_lock, flags);
1223 	port_status = atomic_read(&port->status);
1224 	if ((port_status & ZFCP_STATUS_COMMON_UNBLOCKED)    == 0 ||
1225 	    (port_status & (ZFCP_STATUS_COMMON_ERP_INUSE |
1226 			    ZFCP_STATUS_COMMON_ERP_FAILED)) != 0) {
1227 		/* new ERP of severity >= port triggered elsewhere meanwhile or
1228 		 * local link down (adapter erp_failed but not clear unblock)
1229 		 */
1230 		zfcp_dbf_rec_run_lvl(4, "ertru_p", &port->erp_action);
1231 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1232 		return;
1233 	}
1234 	spin_lock(shost->host_lock);
1235 	__shost_for_each_device(sdev, shost) {
1236 		struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
1237 		int lun_status;
1238 
1239 		if (zsdev->port != port)
1240 			continue;
1241 		/* LUN under port of interest */
1242 		lun_status = atomic_read(&zsdev->status);
1243 		if ((lun_status & ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
1244 			continue; /* unblock rport despite failed LUNs */
1245 		/* LUN recovery not given up yet [maybe follow-up pending] */
1246 		if ((lun_status & ZFCP_STATUS_COMMON_UNBLOCKED) == 0 ||
1247 		    (lun_status & ZFCP_STATUS_COMMON_ERP_INUSE) != 0) {
1248 			/* LUN blocked:
1249 			 * not yet unblocked [LUN recovery pending]
1250 			 * or meanwhile blocked [new LUN recovery triggered]
1251 			 */
1252 			zfcp_dbf_rec_run_lvl(4, "ertru_l", &zsdev->erp_action);
1253 			spin_unlock(shost->host_lock);
1254 			write_unlock_irqrestore(&adapter->erp_lock, flags);
1255 			return;
1256 		}
1257 	}
1258 	/* now port has no child or all children have completed recovery,
1259 	 * and no ERP of severity >= port was meanwhile triggered elsewhere
1260 	 */
1261 	zfcp_scsi_schedule_rport_register(port);
1262 	spin_unlock(shost->host_lock);
1263 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1264 }
1265 
1266 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1267 {
1268 	struct zfcp_adapter *adapter = act->adapter;
1269 	struct zfcp_port *port = act->port;
1270 	struct scsi_device *sdev = act->sdev;
1271 
1272 	switch (act->action) {
1273 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1274 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
1275 			scsi_device_put(sdev);
1276 		zfcp_erp_try_rport_unblock(port);
1277 		break;
1278 
1279 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1280 		/* This switch case might also happen after a forced reopen
1281 		 * was successfully done and thus overwritten with a new
1282 		 * non-forced reopen at `ersfs_2'. In this case, we must not
1283 		 * do the clean-up of the non-forced version.
1284 		 */
1285 		if (act->step != ZFCP_ERP_STEP_UNINITIALIZED)
1286 			if (result == ZFCP_ERP_SUCCEEDED)
1287 				zfcp_erp_try_rport_unblock(port);
1288 		/* fall through */
1289 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1290 		put_device(&port->dev);
1291 		break;
1292 
1293 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1294 		if (result == ZFCP_ERP_SUCCEEDED) {
1295 			register_service_level(&adapter->service_level);
1296 			zfcp_fc_conditional_port_scan(adapter);
1297 			queue_work(adapter->work_queue, &adapter->ns_up_work);
1298 		} else
1299 			unregister_service_level(&adapter->service_level);
1300 
1301 		kref_put(&adapter->ref, zfcp_adapter_release);
1302 		break;
1303 	}
1304 }
1305 
1306 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1307 {
1308 	switch (erp_action->action) {
1309 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1310 		return zfcp_erp_adapter_strategy(erp_action);
1311 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1312 		return zfcp_erp_port_forced_strategy(erp_action);
1313 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1314 		return zfcp_erp_port_strategy(erp_action);
1315 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1316 		return zfcp_erp_lun_strategy(erp_action);
1317 	}
1318 	return ZFCP_ERP_FAILED;
1319 }
1320 
1321 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1322 {
1323 	int retval;
1324 	unsigned long flags;
1325 	struct zfcp_adapter *adapter = erp_action->adapter;
1326 
1327 	kref_get(&adapter->ref);
1328 
1329 	write_lock_irqsave(&adapter->erp_lock, flags);
1330 	zfcp_erp_strategy_check_fsfreq(erp_action);
1331 
1332 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1333 		zfcp_erp_action_dequeue(erp_action);
1334 		retval = ZFCP_ERP_DISMISSED;
1335 		goto unlock;
1336 	}
1337 
1338 	if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
1339 		retval = ZFCP_ERP_FAILED;
1340 		goto check_target;
1341 	}
1342 
1343 	zfcp_erp_action_to_running(erp_action);
1344 
1345 	/* no lock to allow for blocking operations */
1346 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1347 	retval = zfcp_erp_strategy_do_action(erp_action);
1348 	write_lock_irqsave(&adapter->erp_lock, flags);
1349 
1350 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1351 		retval = ZFCP_ERP_CONTINUES;
1352 
1353 	switch (retval) {
1354 	case ZFCP_ERP_NOMEM:
1355 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1356 			++adapter->erp_low_mem_count;
1357 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1358 		}
1359 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1360 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1");
1361 		else {
1362 			zfcp_erp_strategy_memwait(erp_action);
1363 			retval = ZFCP_ERP_CONTINUES;
1364 		}
1365 		goto unlock;
1366 
1367 	case ZFCP_ERP_CONTINUES:
1368 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1369 			--adapter->erp_low_mem_count;
1370 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1371 		}
1372 		goto unlock;
1373 	}
1374 
1375 check_target:
1376 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1377 	zfcp_erp_action_dequeue(erp_action);
1378 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1379 	if (retval == ZFCP_ERP_EXIT)
1380 		goto unlock;
1381 	if (retval == ZFCP_ERP_SUCCEEDED)
1382 		zfcp_erp_strategy_followup_success(erp_action);
1383 	if (retval == ZFCP_ERP_FAILED)
1384 		zfcp_erp_strategy_followup_failed(erp_action);
1385 
1386  unlock:
1387 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1388 
1389 	if (retval != ZFCP_ERP_CONTINUES)
1390 		zfcp_erp_action_cleanup(erp_action, retval);
1391 
1392 	kref_put(&adapter->ref, zfcp_adapter_release);
1393 	return retval;
1394 }
1395 
1396 static int zfcp_erp_thread(void *data)
1397 {
1398 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1399 	struct list_head *next;
1400 	struct zfcp_erp_action *act;
1401 	unsigned long flags;
1402 
1403 	for (;;) {
1404 		wait_event_interruptible(adapter->erp_ready_wq,
1405 			   !list_empty(&adapter->erp_ready_head) ||
1406 			   kthread_should_stop());
1407 
1408 		if (kthread_should_stop())
1409 			break;
1410 
1411 		write_lock_irqsave(&adapter->erp_lock, flags);
1412 		next = adapter->erp_ready_head.next;
1413 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1414 
1415 		if (next != &adapter->erp_ready_head) {
1416 			act = list_entry(next, struct zfcp_erp_action, list);
1417 
1418 			/* there is more to come after dismission, no notify */
1419 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1420 				zfcp_erp_wakeup(adapter);
1421 		}
1422 	}
1423 
1424 	return 0;
1425 }
1426 
1427 /**
1428  * zfcp_erp_thread_setup - Start ERP thread for adapter
1429  * @adapter: Adapter to start the ERP thread for
1430  *
1431  * Returns 0 on success or error code from kernel_thread()
1432  */
1433 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1434 {
1435 	struct task_struct *thread;
1436 
1437 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1438 			     dev_name(&adapter->ccw_device->dev));
1439 	if (IS_ERR(thread)) {
1440 		dev_err(&adapter->ccw_device->dev,
1441 			"Creating an ERP thread for the FCP device failed.\n");
1442 		return PTR_ERR(thread);
1443 	}
1444 
1445 	adapter->erp_thread = thread;
1446 	return 0;
1447 }
1448 
1449 /**
1450  * zfcp_erp_thread_kill - Stop ERP thread.
1451  * @adapter: Adapter where the ERP thread should be stopped.
1452  *
1453  * The caller of this routine ensures that the specified adapter has
1454  * been shut down and that this operation has been completed. Thus,
1455  * there are no pending erp_actions which would need to be handled
1456  * here.
1457  */
1458 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1459 {
1460 	kthread_stop(adapter->erp_thread);
1461 	adapter->erp_thread = NULL;
1462 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1463 	WARN_ON(!list_empty(&adapter->erp_running_head));
1464 }
1465 
1466 /**
1467  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1468  * @adapter: adapter for which to wait for completion of its error recovery
1469  */
1470 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1471 {
1472 	wait_event(adapter->erp_done_wqh,
1473 		   !(atomic_read(&adapter->status) &
1474 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1475 }
1476 
1477 /**
1478  * zfcp_erp_set_adapter_status - set adapter status bits
1479  * @adapter: adapter to change the status
1480  * @mask: status bits to change
1481  *
1482  * Changes in common status bits are propagated to attached ports and LUNs.
1483  */
1484 void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1485 {
1486 	struct zfcp_port *port;
1487 	struct scsi_device *sdev;
1488 	unsigned long flags;
1489 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1490 
1491 	atomic_or(mask, &adapter->status);
1492 
1493 	if (!common_mask)
1494 		return;
1495 
1496 	read_lock_irqsave(&adapter->port_list_lock, flags);
1497 	list_for_each_entry(port, &adapter->port_list, list)
1498 		atomic_or(common_mask, &port->status);
1499 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1500 
1501 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1502 	__shost_for_each_device(sdev, adapter->scsi_host)
1503 		atomic_or(common_mask, &sdev_to_zfcp(sdev)->status);
1504 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1505 }
1506 
1507 /**
1508  * zfcp_erp_clear_adapter_status - clear adapter status bits
1509  * @adapter: adapter to change the status
1510  * @mask: status bits to change
1511  *
1512  * Changes in common status bits are propagated to attached ports and LUNs.
1513  */
1514 void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1515 {
1516 	struct zfcp_port *port;
1517 	struct scsi_device *sdev;
1518 	unsigned long flags;
1519 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1520 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1521 
1522 	atomic_andnot(mask, &adapter->status);
1523 
1524 	if (!common_mask)
1525 		return;
1526 
1527 	if (clear_counter)
1528 		atomic_set(&adapter->erp_counter, 0);
1529 
1530 	read_lock_irqsave(&adapter->port_list_lock, flags);
1531 	list_for_each_entry(port, &adapter->port_list, list) {
1532 		atomic_andnot(common_mask, &port->status);
1533 		if (clear_counter)
1534 			atomic_set(&port->erp_counter, 0);
1535 	}
1536 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1537 
1538 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1539 	__shost_for_each_device(sdev, adapter->scsi_host) {
1540 		atomic_andnot(common_mask, &sdev_to_zfcp(sdev)->status);
1541 		if (clear_counter)
1542 			atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1543 	}
1544 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1545 }
1546 
1547 /**
1548  * zfcp_erp_set_port_status - set port status bits
1549  * @port: port to change the status
1550  * @mask: status bits to change
1551  *
1552  * Changes in common status bits are propagated to attached LUNs.
1553  */
1554 void zfcp_erp_set_port_status(struct zfcp_port *port, u32 mask)
1555 {
1556 	struct scsi_device *sdev;
1557 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1558 	unsigned long flags;
1559 
1560 	atomic_or(mask, &port->status);
1561 
1562 	if (!common_mask)
1563 		return;
1564 
1565 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1566 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1567 		if (sdev_to_zfcp(sdev)->port == port)
1568 			atomic_or(common_mask,
1569 					&sdev_to_zfcp(sdev)->status);
1570 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1571 }
1572 
1573 /**
1574  * zfcp_erp_clear_port_status - clear port status bits
1575  * @port: adapter to change the status
1576  * @mask: status bits to change
1577  *
1578  * Changes in common status bits are propagated to attached LUNs.
1579  */
1580 void zfcp_erp_clear_port_status(struct zfcp_port *port, u32 mask)
1581 {
1582 	struct scsi_device *sdev;
1583 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1584 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1585 	unsigned long flags;
1586 
1587 	atomic_andnot(mask, &port->status);
1588 
1589 	if (!common_mask)
1590 		return;
1591 
1592 	if (clear_counter)
1593 		atomic_set(&port->erp_counter, 0);
1594 
1595 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1596 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1597 		if (sdev_to_zfcp(sdev)->port == port) {
1598 			atomic_andnot(common_mask,
1599 					  &sdev_to_zfcp(sdev)->status);
1600 			if (clear_counter)
1601 				atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1602 		}
1603 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1604 }
1605 
1606 /**
1607  * zfcp_erp_set_lun_status - set lun status bits
1608  * @sdev: SCSI device / lun to set the status bits
1609  * @mask: status bits to change
1610  */
1611 void zfcp_erp_set_lun_status(struct scsi_device *sdev, u32 mask)
1612 {
1613 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1614 
1615 	atomic_or(mask, &zfcp_sdev->status);
1616 }
1617 
1618 /**
1619  * zfcp_erp_clear_lun_status - clear lun status bits
1620  * @sdev: SCSi device / lun to clear the status bits
1621  * @mask: status bits to change
1622  */
1623 void zfcp_erp_clear_lun_status(struct scsi_device *sdev, u32 mask)
1624 {
1625 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1626 
1627 	atomic_andnot(mask, &zfcp_sdev->status);
1628 
1629 	if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1630 		atomic_set(&zfcp_sdev->erp_counter, 0);
1631 }
1632 
1633