xref: /openbmc/linux/drivers/s390/scsi/zfcp_erp.c (revision 82e6fdd6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * zfcp device driver
4  *
5  * Error Recovery Procedures (ERP).
6  *
7  * Copyright IBM Corp. 2002, 2016
8  */
9 
10 #define KMSG_COMPONENT "zfcp"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/kthread.h>
14 #include "zfcp_ext.h"
15 #include "zfcp_reqlist.h"
16 
17 #define ZFCP_MAX_ERPS                   3
18 
19 enum zfcp_erp_act_flags {
20 	ZFCP_STATUS_ERP_TIMEDOUT	= 0x10000000,
21 	ZFCP_STATUS_ERP_CLOSE_ONLY	= 0x01000000,
22 	ZFCP_STATUS_ERP_DISMISSING	= 0x00100000,
23 	ZFCP_STATUS_ERP_DISMISSED	= 0x00200000,
24 	ZFCP_STATUS_ERP_LOWMEM		= 0x00400000,
25 	ZFCP_STATUS_ERP_NO_REF		= 0x00800000,
26 };
27 
28 enum zfcp_erp_steps {
29 	ZFCP_ERP_STEP_UNINITIALIZED	= 0x0000,
30 	ZFCP_ERP_STEP_FSF_XCONFIG	= 0x0001,
31 	ZFCP_ERP_STEP_PHYS_PORT_CLOSING	= 0x0010,
32 	ZFCP_ERP_STEP_PORT_CLOSING	= 0x0100,
33 	ZFCP_ERP_STEP_PORT_OPENING	= 0x0800,
34 	ZFCP_ERP_STEP_LUN_CLOSING	= 0x1000,
35 	ZFCP_ERP_STEP_LUN_OPENING	= 0x2000,
36 };
37 
38 enum zfcp_erp_act_type {
39 	ZFCP_ERP_ACTION_REOPEN_LUN         = 1,
40 	ZFCP_ERP_ACTION_REOPEN_PORT	   = 2,
41 	ZFCP_ERP_ACTION_REOPEN_PORT_FORCED = 3,
42 	ZFCP_ERP_ACTION_REOPEN_ADAPTER     = 4,
43 };
44 
45 enum zfcp_erp_act_state {
46 	ZFCP_ERP_ACTION_RUNNING = 1,
47 	ZFCP_ERP_ACTION_READY   = 2,
48 };
49 
50 enum zfcp_erp_act_result {
51 	ZFCP_ERP_SUCCEEDED = 0,
52 	ZFCP_ERP_FAILED    = 1,
53 	ZFCP_ERP_CONTINUES = 2,
54 	ZFCP_ERP_EXIT      = 3,
55 	ZFCP_ERP_DISMISSED = 4,
56 	ZFCP_ERP_NOMEM     = 5,
57 };
58 
59 static void zfcp_erp_adapter_block(struct zfcp_adapter *adapter, int mask)
60 {
61 	zfcp_erp_clear_adapter_status(adapter,
62 				       ZFCP_STATUS_COMMON_UNBLOCKED | mask);
63 }
64 
65 static int zfcp_erp_action_exists(struct zfcp_erp_action *act)
66 {
67 	struct zfcp_erp_action *curr_act;
68 
69 	list_for_each_entry(curr_act, &act->adapter->erp_running_head, list)
70 		if (act == curr_act)
71 			return ZFCP_ERP_ACTION_RUNNING;
72 	return 0;
73 }
74 
75 static void zfcp_erp_action_ready(struct zfcp_erp_action *act)
76 {
77 	struct zfcp_adapter *adapter = act->adapter;
78 
79 	list_move(&act->list, &act->adapter->erp_ready_head);
80 	zfcp_dbf_rec_run("erardy1", act);
81 	wake_up(&adapter->erp_ready_wq);
82 	zfcp_dbf_rec_run("erardy2", act);
83 }
84 
85 static void zfcp_erp_action_dismiss(struct zfcp_erp_action *act)
86 {
87 	act->status |= ZFCP_STATUS_ERP_DISMISSED;
88 	if (zfcp_erp_action_exists(act) == ZFCP_ERP_ACTION_RUNNING)
89 		zfcp_erp_action_ready(act);
90 }
91 
92 static void zfcp_erp_action_dismiss_lun(struct scsi_device *sdev)
93 {
94 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
95 
96 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
97 		zfcp_erp_action_dismiss(&zfcp_sdev->erp_action);
98 }
99 
100 static void zfcp_erp_action_dismiss_port(struct zfcp_port *port)
101 {
102 	struct scsi_device *sdev;
103 
104 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
105 		zfcp_erp_action_dismiss(&port->erp_action);
106 	else {
107 		spin_lock(port->adapter->scsi_host->host_lock);
108 		__shost_for_each_device(sdev, port->adapter->scsi_host)
109 			if (sdev_to_zfcp(sdev)->port == port)
110 				zfcp_erp_action_dismiss_lun(sdev);
111 		spin_unlock(port->adapter->scsi_host->host_lock);
112 	}
113 }
114 
115 static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *adapter)
116 {
117 	struct zfcp_port *port;
118 
119 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_INUSE)
120 		zfcp_erp_action_dismiss(&adapter->erp_action);
121 	else {
122 		read_lock(&adapter->port_list_lock);
123 		list_for_each_entry(port, &adapter->port_list, list)
124 		    zfcp_erp_action_dismiss_port(port);
125 		read_unlock(&adapter->port_list_lock);
126 	}
127 }
128 
129 static int zfcp_erp_required_act(int want, struct zfcp_adapter *adapter,
130 				 struct zfcp_port *port,
131 				 struct scsi_device *sdev)
132 {
133 	int need = want;
134 	int l_status, p_status, a_status;
135 	struct zfcp_scsi_dev *zfcp_sdev;
136 
137 	switch (want) {
138 	case ZFCP_ERP_ACTION_REOPEN_LUN:
139 		zfcp_sdev = sdev_to_zfcp(sdev);
140 		l_status = atomic_read(&zfcp_sdev->status);
141 		if (l_status & ZFCP_STATUS_COMMON_ERP_INUSE)
142 			return 0;
143 		p_status = atomic_read(&port->status);
144 		if (!(p_status & ZFCP_STATUS_COMMON_RUNNING) ||
145 		      p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
146 			return 0;
147 		if (!(p_status & ZFCP_STATUS_COMMON_UNBLOCKED))
148 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
149 		/* fall through */
150 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
151 		p_status = atomic_read(&port->status);
152 		if (!(p_status & ZFCP_STATUS_COMMON_OPEN))
153 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
154 		/* fall through */
155 	case ZFCP_ERP_ACTION_REOPEN_PORT:
156 		p_status = atomic_read(&port->status);
157 		if (p_status & ZFCP_STATUS_COMMON_ERP_INUSE)
158 			return 0;
159 		a_status = atomic_read(&adapter->status);
160 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) ||
161 		      a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
162 			return 0;
163 		if (p_status & ZFCP_STATUS_COMMON_NOESC)
164 			return need;
165 		if (!(a_status & ZFCP_STATUS_COMMON_UNBLOCKED))
166 			need = ZFCP_ERP_ACTION_REOPEN_ADAPTER;
167 		/* fall through */
168 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
169 		a_status = atomic_read(&adapter->status);
170 		if (a_status & ZFCP_STATUS_COMMON_ERP_INUSE)
171 			return 0;
172 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) &&
173 		    !(a_status & ZFCP_STATUS_COMMON_OPEN))
174 			return 0; /* shutdown requested for closed adapter */
175 	}
176 
177 	return need;
178 }
179 
180 static struct zfcp_erp_action *zfcp_erp_setup_act(int need, u32 act_status,
181 						  struct zfcp_adapter *adapter,
182 						  struct zfcp_port *port,
183 						  struct scsi_device *sdev)
184 {
185 	struct zfcp_erp_action *erp_action;
186 	struct zfcp_scsi_dev *zfcp_sdev;
187 
188 	switch (need) {
189 	case ZFCP_ERP_ACTION_REOPEN_LUN:
190 		zfcp_sdev = sdev_to_zfcp(sdev);
191 		if (!(act_status & ZFCP_STATUS_ERP_NO_REF))
192 			if (scsi_device_get(sdev))
193 				return NULL;
194 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE,
195 				&zfcp_sdev->status);
196 		erp_action = &zfcp_sdev->erp_action;
197 		WARN_ON_ONCE(erp_action->port != port);
198 		WARN_ON_ONCE(erp_action->sdev != sdev);
199 		if (!(atomic_read(&zfcp_sdev->status) &
200 		      ZFCP_STATUS_COMMON_RUNNING))
201 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
202 		break;
203 
204 	case ZFCP_ERP_ACTION_REOPEN_PORT:
205 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
206 		if (!get_device(&port->dev))
207 			return NULL;
208 		zfcp_erp_action_dismiss_port(port);
209 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
210 		erp_action = &port->erp_action;
211 		WARN_ON_ONCE(erp_action->port != port);
212 		WARN_ON_ONCE(erp_action->sdev != NULL);
213 		if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_RUNNING))
214 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
215 		break;
216 
217 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
218 		kref_get(&adapter->ref);
219 		zfcp_erp_action_dismiss_adapter(adapter);
220 		atomic_or(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
221 		erp_action = &adapter->erp_action;
222 		WARN_ON_ONCE(erp_action->port != NULL);
223 		WARN_ON_ONCE(erp_action->sdev != NULL);
224 		if (!(atomic_read(&adapter->status) &
225 		      ZFCP_STATUS_COMMON_RUNNING))
226 			act_status |= ZFCP_STATUS_ERP_CLOSE_ONLY;
227 		break;
228 
229 	default:
230 		return NULL;
231 	}
232 
233 	WARN_ON_ONCE(erp_action->adapter != adapter);
234 	memset(&erp_action->list, 0, sizeof(erp_action->list));
235 	memset(&erp_action->timer, 0, sizeof(erp_action->timer));
236 	erp_action->step = ZFCP_ERP_STEP_UNINITIALIZED;
237 	erp_action->fsf_req_id = 0;
238 	erp_action->action = need;
239 	erp_action->status = act_status;
240 
241 	return erp_action;
242 }
243 
244 static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
245 				   struct zfcp_port *port,
246 				   struct scsi_device *sdev,
247 				   char *id, u32 act_status)
248 {
249 	int retval = 1, need;
250 	struct zfcp_erp_action *act;
251 
252 	if (!adapter->erp_thread)
253 		return -EIO;
254 
255 	need = zfcp_erp_required_act(want, adapter, port, sdev);
256 	if (!need)
257 		goto out;
258 
259 	act = zfcp_erp_setup_act(need, act_status, adapter, port, sdev);
260 	if (!act)
261 		goto out;
262 	atomic_or(ZFCP_STATUS_ADAPTER_ERP_PENDING, &adapter->status);
263 	++adapter->erp_total_count;
264 	list_add_tail(&act->list, &adapter->erp_ready_head);
265 	wake_up(&adapter->erp_ready_wq);
266 	retval = 0;
267  out:
268 	zfcp_dbf_rec_trig(id, adapter, port, sdev, want, need);
269 	return retval;
270 }
271 
272 static int _zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter,
273 				    int clear_mask, char *id)
274 {
275 	zfcp_erp_adapter_block(adapter, clear_mask);
276 	zfcp_scsi_schedule_rports_block(adapter);
277 
278 	/* ensure propagation of failed status to new devices */
279 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
280 		zfcp_erp_set_adapter_status(adapter,
281 					    ZFCP_STATUS_COMMON_ERP_FAILED);
282 		return -EIO;
283 	}
284 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER,
285 				       adapter, NULL, NULL, id, 0);
286 }
287 
288 /**
289  * zfcp_erp_adapter_reopen - Reopen adapter.
290  * @adapter: Adapter to reopen.
291  * @clear: Status flags to clear.
292  * @id: Id for debug trace event.
293  */
294 void zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter, int clear, char *id)
295 {
296 	unsigned long flags;
297 
298 	zfcp_erp_adapter_block(adapter, clear);
299 	zfcp_scsi_schedule_rports_block(adapter);
300 
301 	write_lock_irqsave(&adapter->erp_lock, flags);
302 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
303 		zfcp_erp_set_adapter_status(adapter,
304 					    ZFCP_STATUS_COMMON_ERP_FAILED);
305 	else
306 		zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER, adapter,
307 					NULL, NULL, id, 0);
308 	write_unlock_irqrestore(&adapter->erp_lock, flags);
309 }
310 
311 /**
312  * zfcp_erp_adapter_shutdown - Shutdown adapter.
313  * @adapter: Adapter to shut down.
314  * @clear: Status flags to clear.
315  * @id: Id for debug trace event.
316  */
317 void zfcp_erp_adapter_shutdown(struct zfcp_adapter *adapter, int clear,
318 			       char *id)
319 {
320 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
321 	zfcp_erp_adapter_reopen(adapter, clear | flags, id);
322 }
323 
324 /**
325  * zfcp_erp_port_shutdown - Shutdown port
326  * @port: Port to shut down.
327  * @clear: Status flags to clear.
328  * @id: Id for debug trace event.
329  */
330 void zfcp_erp_port_shutdown(struct zfcp_port *port, int clear, char *id)
331 {
332 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
333 	zfcp_erp_port_reopen(port, clear | flags, id);
334 }
335 
336 static void zfcp_erp_port_block(struct zfcp_port *port, int clear)
337 {
338 	zfcp_erp_clear_port_status(port,
339 				    ZFCP_STATUS_COMMON_UNBLOCKED | clear);
340 }
341 
342 static void _zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear,
343 					 char *id)
344 {
345 	zfcp_erp_port_block(port, clear);
346 	zfcp_scsi_schedule_rport_block(port);
347 
348 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
349 		return;
350 
351 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
352 				port->adapter, port, NULL, id, 0);
353 }
354 
355 /**
356  * zfcp_erp_port_forced_reopen - Forced close of port and open again
357  * @port: Port to force close and to reopen.
358  * @clear: Status flags to clear.
359  * @id: Id for debug trace event.
360  */
361 void zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear, char *id)
362 {
363 	unsigned long flags;
364 	struct zfcp_adapter *adapter = port->adapter;
365 
366 	write_lock_irqsave(&adapter->erp_lock, flags);
367 	_zfcp_erp_port_forced_reopen(port, clear, id);
368 	write_unlock_irqrestore(&adapter->erp_lock, flags);
369 }
370 
371 static int _zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id)
372 {
373 	zfcp_erp_port_block(port, clear);
374 	zfcp_scsi_schedule_rport_block(port);
375 
376 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
377 		/* ensure propagation of failed status to new devices */
378 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
379 		return -EIO;
380 	}
381 
382 	return zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT,
383 				       port->adapter, port, NULL, id, 0);
384 }
385 
386 /**
387  * zfcp_erp_port_reopen - trigger remote port recovery
388  * @port: port to recover
389  * @clear_mask: flags in port status to be cleared
390  * @id: Id for debug trace event.
391  *
392  * Returns 0 if recovery has been triggered, < 0 if not.
393  */
394 int zfcp_erp_port_reopen(struct zfcp_port *port, int clear, char *id)
395 {
396 	int retval;
397 	unsigned long flags;
398 	struct zfcp_adapter *adapter = port->adapter;
399 
400 	write_lock_irqsave(&adapter->erp_lock, flags);
401 	retval = _zfcp_erp_port_reopen(port, clear, id);
402 	write_unlock_irqrestore(&adapter->erp_lock, flags);
403 
404 	return retval;
405 }
406 
407 static void zfcp_erp_lun_block(struct scsi_device *sdev, int clear_mask)
408 {
409 	zfcp_erp_clear_lun_status(sdev,
410 				  ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask);
411 }
412 
413 static void _zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id,
414 				 u32 act_status)
415 {
416 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
417 	struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
418 
419 	zfcp_erp_lun_block(sdev, clear);
420 
421 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
422 		return;
423 
424 	zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_LUN, adapter,
425 				zfcp_sdev->port, sdev, id, act_status);
426 }
427 
428 /**
429  * zfcp_erp_lun_reopen - initiate reopen of a LUN
430  * @sdev: SCSI device / LUN to be reopened
431  * @clear_mask: specifies flags in LUN status to be cleared
432  * @id: Id for debug trace event.
433  *
434  * Return: 0 on success, < 0 on error
435  */
436 void zfcp_erp_lun_reopen(struct scsi_device *sdev, int clear, char *id)
437 {
438 	unsigned long flags;
439 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
440 	struct zfcp_port *port = zfcp_sdev->port;
441 	struct zfcp_adapter *adapter = port->adapter;
442 
443 	write_lock_irqsave(&adapter->erp_lock, flags);
444 	_zfcp_erp_lun_reopen(sdev, clear, id, 0);
445 	write_unlock_irqrestore(&adapter->erp_lock, flags);
446 }
447 
448 /**
449  * zfcp_erp_lun_shutdown - Shutdown LUN
450  * @sdev: SCSI device / LUN to shut down.
451  * @clear: Status flags to clear.
452  * @id: Id for debug trace event.
453  */
454 void zfcp_erp_lun_shutdown(struct scsi_device *sdev, int clear, char *id)
455 {
456 	int flags = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
457 	zfcp_erp_lun_reopen(sdev, clear | flags, id);
458 }
459 
460 /**
461  * zfcp_erp_lun_shutdown_wait - Shutdown LUN and wait for erp completion
462  * @sdev: SCSI device / LUN to shut down.
463  * @id: Id for debug trace event.
464  *
465  * Do not acquire a reference for the LUN when creating the ERP
466  * action. It is safe, because this function waits for the ERP to
467  * complete first. This allows to shutdown the LUN, even when the SCSI
468  * device is in the state SDEV_DEL when scsi_device_get will fail.
469  */
470 void zfcp_erp_lun_shutdown_wait(struct scsi_device *sdev, char *id)
471 {
472 	unsigned long flags;
473 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
474 	struct zfcp_port *port = zfcp_sdev->port;
475 	struct zfcp_adapter *adapter = port->adapter;
476 	int clear = ZFCP_STATUS_COMMON_RUNNING | ZFCP_STATUS_COMMON_ERP_FAILED;
477 
478 	write_lock_irqsave(&adapter->erp_lock, flags);
479 	_zfcp_erp_lun_reopen(sdev, clear, id, ZFCP_STATUS_ERP_NO_REF);
480 	write_unlock_irqrestore(&adapter->erp_lock, flags);
481 
482 	zfcp_erp_wait(adapter);
483 }
484 
485 static int status_change_set(unsigned long mask, atomic_t *status)
486 {
487 	return (atomic_read(status) ^ mask) & mask;
488 }
489 
490 static void zfcp_erp_adapter_unblock(struct zfcp_adapter *adapter)
491 {
492 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status))
493 		zfcp_dbf_rec_run("eraubl1", &adapter->erp_action);
494 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status);
495 }
496 
497 static void zfcp_erp_port_unblock(struct zfcp_port *port)
498 {
499 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status))
500 		zfcp_dbf_rec_run("erpubl1", &port->erp_action);
501 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status);
502 }
503 
504 static void zfcp_erp_lun_unblock(struct scsi_device *sdev)
505 {
506 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
507 
508 	if (status_change_set(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status))
509 		zfcp_dbf_rec_run("erlubl1", &sdev_to_zfcp(sdev)->erp_action);
510 	atomic_or(ZFCP_STATUS_COMMON_UNBLOCKED, &zfcp_sdev->status);
511 }
512 
513 static void zfcp_erp_action_to_running(struct zfcp_erp_action *erp_action)
514 {
515 	list_move(&erp_action->list, &erp_action->adapter->erp_running_head);
516 	zfcp_dbf_rec_run("erator1", erp_action);
517 }
518 
519 static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
520 {
521 	struct zfcp_adapter *adapter = act->adapter;
522 	struct zfcp_fsf_req *req;
523 
524 	if (!act->fsf_req_id)
525 		return;
526 
527 	spin_lock(&adapter->req_list->lock);
528 	req = _zfcp_reqlist_find(adapter->req_list, act->fsf_req_id);
529 	if (req && req->erp_action == act) {
530 		if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
531 				   ZFCP_STATUS_ERP_TIMEDOUT)) {
532 			req->status |= ZFCP_STATUS_FSFREQ_DISMISSED;
533 			zfcp_dbf_rec_run("erscf_1", act);
534 			req->erp_action = NULL;
535 		}
536 		if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
537 			zfcp_dbf_rec_run("erscf_2", act);
538 		if (req->status & ZFCP_STATUS_FSFREQ_DISMISSED)
539 			act->fsf_req_id = 0;
540 	} else
541 		act->fsf_req_id = 0;
542 	spin_unlock(&adapter->req_list->lock);
543 }
544 
545 /**
546  * zfcp_erp_notify - Trigger ERP action.
547  * @erp_action: ERP action to continue.
548  * @set_mask: ERP action status flags to set.
549  */
550 void zfcp_erp_notify(struct zfcp_erp_action *erp_action, unsigned long set_mask)
551 {
552 	struct zfcp_adapter *adapter = erp_action->adapter;
553 	unsigned long flags;
554 
555 	write_lock_irqsave(&adapter->erp_lock, flags);
556 	if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING) {
557 		erp_action->status |= set_mask;
558 		zfcp_erp_action_ready(erp_action);
559 	}
560 	write_unlock_irqrestore(&adapter->erp_lock, flags);
561 }
562 
563 /**
564  * zfcp_erp_timeout_handler - Trigger ERP action from timed out ERP request
565  * @data: ERP action (from timer data)
566  */
567 void zfcp_erp_timeout_handler(struct timer_list *t)
568 {
569 	struct zfcp_fsf_req *fsf_req = from_timer(fsf_req, t, timer);
570 	struct zfcp_erp_action *act = fsf_req->erp_action;
571 
572 	zfcp_erp_notify(act, ZFCP_STATUS_ERP_TIMEDOUT);
573 }
574 
575 static void zfcp_erp_memwait_handler(struct timer_list *t)
576 {
577 	struct zfcp_erp_action *act = from_timer(act, t, timer);
578 
579 	zfcp_erp_notify(act, 0);
580 }
581 
582 static void zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
583 {
584 	timer_setup(&erp_action->timer, zfcp_erp_memwait_handler, 0);
585 	erp_action->timer.expires = jiffies + HZ;
586 	add_timer(&erp_action->timer);
587 }
588 
589 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
590 				      int clear, char *id)
591 {
592 	struct zfcp_port *port;
593 
594 	read_lock(&adapter->port_list_lock);
595 	list_for_each_entry(port, &adapter->port_list, list)
596 		_zfcp_erp_port_reopen(port, clear, id);
597 	read_unlock(&adapter->port_list_lock);
598 }
599 
600 static void _zfcp_erp_lun_reopen_all(struct zfcp_port *port, int clear,
601 				     char *id)
602 {
603 	struct scsi_device *sdev;
604 
605 	spin_lock(port->adapter->scsi_host->host_lock);
606 	__shost_for_each_device(sdev, port->adapter->scsi_host)
607 		if (sdev_to_zfcp(sdev)->port == port)
608 			_zfcp_erp_lun_reopen(sdev, clear, id, 0);
609 	spin_unlock(port->adapter->scsi_host->host_lock);
610 }
611 
612 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
613 {
614 	switch (act->action) {
615 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
616 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1");
617 		break;
618 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
619 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2");
620 		break;
621 	case ZFCP_ERP_ACTION_REOPEN_PORT:
622 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3");
623 		break;
624 	case ZFCP_ERP_ACTION_REOPEN_LUN:
625 		_zfcp_erp_lun_reopen(act->sdev, 0, "ersff_4", 0);
626 		break;
627 	}
628 }
629 
630 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
631 {
632 	switch (act->action) {
633 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
634 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1");
635 		break;
636 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
637 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2");
638 		break;
639 	case ZFCP_ERP_ACTION_REOPEN_PORT:
640 		_zfcp_erp_lun_reopen_all(act->port, 0, "ersfs_3");
641 		break;
642 	}
643 }
644 
645 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
646 {
647 	unsigned long flags;
648 
649 	read_lock_irqsave(&adapter->erp_lock, flags);
650 	if (list_empty(&adapter->erp_ready_head) &&
651 	    list_empty(&adapter->erp_running_head)) {
652 			atomic_andnot(ZFCP_STATUS_ADAPTER_ERP_PENDING,
653 					  &adapter->status);
654 			wake_up(&adapter->erp_done_wqh);
655 	}
656 	read_unlock_irqrestore(&adapter->erp_lock, flags);
657 }
658 
659 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
660 {
661 	struct zfcp_port *port;
662 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
663 				 adapter->peer_d_id);
664 	if (IS_ERR(port)) /* error or port already attached */
665 		return;
666 	_zfcp_erp_port_reopen(port, 0, "ereptp1");
667 }
668 
669 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
670 {
671 	int retries;
672 	int sleep = 1;
673 	struct zfcp_adapter *adapter = erp_action->adapter;
674 
675 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
676 
677 	for (retries = 7; retries; retries--) {
678 		atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
679 				  &adapter->status);
680 		write_lock_irq(&adapter->erp_lock);
681 		zfcp_erp_action_to_running(erp_action);
682 		write_unlock_irq(&adapter->erp_lock);
683 		if (zfcp_fsf_exchange_config_data(erp_action)) {
684 			atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
685 					  &adapter->status);
686 			return ZFCP_ERP_FAILED;
687 		}
688 
689 		wait_event(adapter->erp_ready_wq,
690 			   !list_empty(&adapter->erp_ready_head));
691 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
692 			break;
693 
694 		if (!(atomic_read(&adapter->status) &
695 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
696 			break;
697 
698 		ssleep(sleep);
699 		sleep *= 2;
700 	}
701 
702 	atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
703 			  &adapter->status);
704 
705 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
706 		return ZFCP_ERP_FAILED;
707 
708 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
709 		zfcp_erp_enqueue_ptp_port(adapter);
710 
711 	return ZFCP_ERP_SUCCEEDED;
712 }
713 
714 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
715 {
716 	int ret;
717 	struct zfcp_adapter *adapter = act->adapter;
718 
719 	write_lock_irq(&adapter->erp_lock);
720 	zfcp_erp_action_to_running(act);
721 	write_unlock_irq(&adapter->erp_lock);
722 
723 	ret = zfcp_fsf_exchange_port_data(act);
724 	if (ret == -EOPNOTSUPP)
725 		return ZFCP_ERP_SUCCEEDED;
726 	if (ret)
727 		return ZFCP_ERP_FAILED;
728 
729 	zfcp_dbf_rec_run("erasox1", act);
730 	wait_event(adapter->erp_ready_wq,
731 		   !list_empty(&adapter->erp_ready_head));
732 	zfcp_dbf_rec_run("erasox2", act);
733 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
734 		return ZFCP_ERP_FAILED;
735 
736 	return ZFCP_ERP_SUCCEEDED;
737 }
738 
739 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
740 {
741 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
742 		return ZFCP_ERP_FAILED;
743 
744 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
745 		return ZFCP_ERP_FAILED;
746 
747 	if (mempool_resize(act->adapter->pool.sr_data,
748 			   act->adapter->stat_read_buf_num))
749 		return ZFCP_ERP_FAILED;
750 
751 	if (mempool_resize(act->adapter->pool.status_read_req,
752 			   act->adapter->stat_read_buf_num))
753 		return ZFCP_ERP_FAILED;
754 
755 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
756 	if (zfcp_status_read_refill(act->adapter))
757 		return ZFCP_ERP_FAILED;
758 
759 	return ZFCP_ERP_SUCCEEDED;
760 }
761 
762 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
763 {
764 	struct zfcp_adapter *adapter = act->adapter;
765 
766 	/* close queues to ensure that buffers are not accessed by adapter */
767 	zfcp_qdio_close(adapter->qdio);
768 	zfcp_fsf_req_dismiss_all(adapter);
769 	adapter->fsf_req_seq_no = 0;
770 	zfcp_fc_wka_ports_force_offline(adapter->gs);
771 	/* all ports and LUNs are closed */
772 	zfcp_erp_clear_adapter_status(adapter, ZFCP_STATUS_COMMON_OPEN);
773 
774 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
775 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
776 }
777 
778 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
779 {
780 	struct zfcp_adapter *adapter = act->adapter;
781 
782 	if (zfcp_qdio_open(adapter->qdio)) {
783 		atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
784 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
785 				  &adapter->status);
786 		return ZFCP_ERP_FAILED;
787 	}
788 
789 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
790 		zfcp_erp_adapter_strategy_close(act);
791 		return ZFCP_ERP_FAILED;
792 	}
793 
794 	atomic_or(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
795 
796 	return ZFCP_ERP_SUCCEEDED;
797 }
798 
799 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
800 {
801 	struct zfcp_adapter *adapter = act->adapter;
802 
803 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
804 		zfcp_erp_adapter_strategy_close(act);
805 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
806 			return ZFCP_ERP_EXIT;
807 	}
808 
809 	if (zfcp_erp_adapter_strategy_open(act)) {
810 		ssleep(8);
811 		return ZFCP_ERP_FAILED;
812 	}
813 
814 	return ZFCP_ERP_SUCCEEDED;
815 }
816 
817 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
818 {
819 	int retval;
820 
821 	retval = zfcp_fsf_close_physical_port(act);
822 	if (retval == -ENOMEM)
823 		return ZFCP_ERP_NOMEM;
824 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
825 	if (retval)
826 		return ZFCP_ERP_FAILED;
827 
828 	return ZFCP_ERP_CONTINUES;
829 }
830 
831 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
832 {
833 	struct zfcp_port *port = erp_action->port;
834 	int status = atomic_read(&port->status);
835 
836 	switch (erp_action->step) {
837 	case ZFCP_ERP_STEP_UNINITIALIZED:
838 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
839 		    (status & ZFCP_STATUS_COMMON_OPEN))
840 			return zfcp_erp_port_forced_strategy_close(erp_action);
841 		else
842 			return ZFCP_ERP_FAILED;
843 
844 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
845 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
846 			return ZFCP_ERP_SUCCEEDED;
847 	}
848 	return ZFCP_ERP_FAILED;
849 }
850 
851 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
852 {
853 	int retval;
854 
855 	retval = zfcp_fsf_close_port(erp_action);
856 	if (retval == -ENOMEM)
857 		return ZFCP_ERP_NOMEM;
858 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
859 	if (retval)
860 		return ZFCP_ERP_FAILED;
861 	return ZFCP_ERP_CONTINUES;
862 }
863 
864 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
865 {
866 	int retval;
867 
868 	retval = zfcp_fsf_open_port(erp_action);
869 	if (retval == -ENOMEM)
870 		return ZFCP_ERP_NOMEM;
871 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
872 	if (retval)
873 		return ZFCP_ERP_FAILED;
874 	return ZFCP_ERP_CONTINUES;
875 }
876 
877 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
878 {
879 	struct zfcp_adapter *adapter = act->adapter;
880 	struct zfcp_port *port = act->port;
881 
882 	if (port->wwpn != adapter->peer_wwpn) {
883 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
884 		return ZFCP_ERP_FAILED;
885 	}
886 	port->d_id = adapter->peer_d_id;
887 	return zfcp_erp_port_strategy_open_port(act);
888 }
889 
890 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
891 {
892 	struct zfcp_adapter *adapter = act->adapter;
893 	struct zfcp_port *port = act->port;
894 	int p_status = atomic_read(&port->status);
895 
896 	switch (act->step) {
897 	case ZFCP_ERP_STEP_UNINITIALIZED:
898 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
899 	case ZFCP_ERP_STEP_PORT_CLOSING:
900 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
901 			return zfcp_erp_open_ptp_port(act);
902 		if (!port->d_id) {
903 			zfcp_fc_trigger_did_lookup(port);
904 			return ZFCP_ERP_EXIT;
905 		}
906 		return zfcp_erp_port_strategy_open_port(act);
907 
908 	case ZFCP_ERP_STEP_PORT_OPENING:
909 		/* D_ID might have changed during open */
910 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
911 			if (!port->d_id) {
912 				zfcp_fc_trigger_did_lookup(port);
913 				return ZFCP_ERP_EXIT;
914 			}
915 			return ZFCP_ERP_SUCCEEDED;
916 		}
917 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
918 			port->d_id = 0;
919 			return ZFCP_ERP_FAILED;
920 		}
921 		/* fall through otherwise */
922 	}
923 	return ZFCP_ERP_FAILED;
924 }
925 
926 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
927 {
928 	struct zfcp_port *port = erp_action->port;
929 	int p_status = atomic_read(&port->status);
930 
931 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
932 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
933 		goto close_init_done;
934 
935 	switch (erp_action->step) {
936 	case ZFCP_ERP_STEP_UNINITIALIZED:
937 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
938 			return zfcp_erp_port_strategy_close(erp_action);
939 		break;
940 
941 	case ZFCP_ERP_STEP_PORT_CLOSING:
942 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
943 			return ZFCP_ERP_FAILED;
944 		break;
945 	}
946 
947 close_init_done:
948 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
949 		return ZFCP_ERP_EXIT;
950 
951 	return zfcp_erp_port_strategy_open_common(erp_action);
952 }
953 
954 static void zfcp_erp_lun_strategy_clearstati(struct scsi_device *sdev)
955 {
956 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
957 
958 	atomic_andnot(ZFCP_STATUS_COMMON_ACCESS_DENIED,
959 			  &zfcp_sdev->status);
960 }
961 
962 static int zfcp_erp_lun_strategy_close(struct zfcp_erp_action *erp_action)
963 {
964 	int retval = zfcp_fsf_close_lun(erp_action);
965 	if (retval == -ENOMEM)
966 		return ZFCP_ERP_NOMEM;
967 	erp_action->step = ZFCP_ERP_STEP_LUN_CLOSING;
968 	if (retval)
969 		return ZFCP_ERP_FAILED;
970 	return ZFCP_ERP_CONTINUES;
971 }
972 
973 static int zfcp_erp_lun_strategy_open(struct zfcp_erp_action *erp_action)
974 {
975 	int retval = zfcp_fsf_open_lun(erp_action);
976 	if (retval == -ENOMEM)
977 		return ZFCP_ERP_NOMEM;
978 	erp_action->step = ZFCP_ERP_STEP_LUN_OPENING;
979 	if (retval)
980 		return  ZFCP_ERP_FAILED;
981 	return ZFCP_ERP_CONTINUES;
982 }
983 
984 static int zfcp_erp_lun_strategy(struct zfcp_erp_action *erp_action)
985 {
986 	struct scsi_device *sdev = erp_action->sdev;
987 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
988 
989 	switch (erp_action->step) {
990 	case ZFCP_ERP_STEP_UNINITIALIZED:
991 		zfcp_erp_lun_strategy_clearstati(sdev);
992 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
993 			return zfcp_erp_lun_strategy_close(erp_action);
994 		/* already closed, fall through */
995 	case ZFCP_ERP_STEP_LUN_CLOSING:
996 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
997 			return ZFCP_ERP_FAILED;
998 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
999 			return ZFCP_ERP_EXIT;
1000 		return zfcp_erp_lun_strategy_open(erp_action);
1001 
1002 	case ZFCP_ERP_STEP_LUN_OPENING:
1003 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
1004 			return ZFCP_ERP_SUCCEEDED;
1005 	}
1006 	return ZFCP_ERP_FAILED;
1007 }
1008 
1009 static int zfcp_erp_strategy_check_lun(struct scsi_device *sdev, int result)
1010 {
1011 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1012 
1013 	switch (result) {
1014 	case ZFCP_ERP_SUCCEEDED :
1015 		atomic_set(&zfcp_sdev->erp_counter, 0);
1016 		zfcp_erp_lun_unblock(sdev);
1017 		break;
1018 	case ZFCP_ERP_FAILED :
1019 		atomic_inc(&zfcp_sdev->erp_counter);
1020 		if (atomic_read(&zfcp_sdev->erp_counter) > ZFCP_MAX_ERPS) {
1021 			dev_err(&zfcp_sdev->port->adapter->ccw_device->dev,
1022 				"ERP failed for LUN 0x%016Lx on "
1023 				"port 0x%016Lx\n",
1024 				(unsigned long long)zfcp_scsi_dev_lun(sdev),
1025 				(unsigned long long)zfcp_sdev->port->wwpn);
1026 			zfcp_erp_set_lun_status(sdev,
1027 						ZFCP_STATUS_COMMON_ERP_FAILED);
1028 		}
1029 		break;
1030 	}
1031 
1032 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1033 		zfcp_erp_lun_block(sdev, 0);
1034 		result = ZFCP_ERP_EXIT;
1035 	}
1036 	return result;
1037 }
1038 
1039 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1040 {
1041 	switch (result) {
1042 	case ZFCP_ERP_SUCCEEDED :
1043 		atomic_set(&port->erp_counter, 0);
1044 		zfcp_erp_port_unblock(port);
1045 		break;
1046 
1047 	case ZFCP_ERP_FAILED :
1048 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1049 			zfcp_erp_port_block(port, 0);
1050 			result = ZFCP_ERP_EXIT;
1051 		}
1052 		atomic_inc(&port->erp_counter);
1053 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1054 			dev_err(&port->adapter->ccw_device->dev,
1055 				"ERP failed for remote port 0x%016Lx\n",
1056 				(unsigned long long)port->wwpn);
1057 			zfcp_erp_set_port_status(port,
1058 					 ZFCP_STATUS_COMMON_ERP_FAILED);
1059 		}
1060 		break;
1061 	}
1062 
1063 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1064 		zfcp_erp_port_block(port, 0);
1065 		result = ZFCP_ERP_EXIT;
1066 	}
1067 	return result;
1068 }
1069 
1070 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1071 					   int result)
1072 {
1073 	switch (result) {
1074 	case ZFCP_ERP_SUCCEEDED :
1075 		atomic_set(&adapter->erp_counter, 0);
1076 		zfcp_erp_adapter_unblock(adapter);
1077 		break;
1078 
1079 	case ZFCP_ERP_FAILED :
1080 		atomic_inc(&adapter->erp_counter);
1081 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1082 			dev_err(&adapter->ccw_device->dev,
1083 				"ERP cannot recover an error "
1084 				"on the FCP device\n");
1085 			zfcp_erp_set_adapter_status(adapter,
1086 					    ZFCP_STATUS_COMMON_ERP_FAILED);
1087 		}
1088 		break;
1089 	}
1090 
1091 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1092 		zfcp_erp_adapter_block(adapter, 0);
1093 		result = ZFCP_ERP_EXIT;
1094 	}
1095 	return result;
1096 }
1097 
1098 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1099 					  int result)
1100 {
1101 	struct zfcp_adapter *adapter = erp_action->adapter;
1102 	struct zfcp_port *port = erp_action->port;
1103 	struct scsi_device *sdev = erp_action->sdev;
1104 
1105 	switch (erp_action->action) {
1106 
1107 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1108 		result = zfcp_erp_strategy_check_lun(sdev, result);
1109 		break;
1110 
1111 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1112 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1113 		result = zfcp_erp_strategy_check_port(port, result);
1114 		break;
1115 
1116 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1117 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1118 		break;
1119 	}
1120 	return result;
1121 }
1122 
1123 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1124 {
1125 	int status = atomic_read(target_status);
1126 
1127 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1128 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1129 		return 1; /* take it online */
1130 
1131 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1132 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1133 		return 1; /* take it offline */
1134 
1135 	return 0;
1136 }
1137 
1138 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1139 {
1140 	int action = act->action;
1141 	struct zfcp_adapter *adapter = act->adapter;
1142 	struct zfcp_port *port = act->port;
1143 	struct scsi_device *sdev = act->sdev;
1144 	struct zfcp_scsi_dev *zfcp_sdev;
1145 	u32 erp_status = act->status;
1146 
1147 	switch (action) {
1148 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1149 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1150 			_zfcp_erp_adapter_reopen(adapter,
1151 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1152 						 "ersscg1");
1153 			return ZFCP_ERP_EXIT;
1154 		}
1155 		break;
1156 
1157 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1158 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1159 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1160 			_zfcp_erp_port_reopen(port,
1161 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1162 					      "ersscg2");
1163 			return ZFCP_ERP_EXIT;
1164 		}
1165 		break;
1166 
1167 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1168 		zfcp_sdev = sdev_to_zfcp(sdev);
1169 		if (zfcp_erp_strat_change_det(&zfcp_sdev->status, erp_status)) {
1170 			_zfcp_erp_lun_reopen(sdev,
1171 					     ZFCP_STATUS_COMMON_ERP_FAILED,
1172 					     "ersscg3", 0);
1173 			return ZFCP_ERP_EXIT;
1174 		}
1175 		break;
1176 	}
1177 	return ret;
1178 }
1179 
1180 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1181 {
1182 	struct zfcp_adapter *adapter = erp_action->adapter;
1183 	struct zfcp_scsi_dev *zfcp_sdev;
1184 
1185 	adapter->erp_total_count--;
1186 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1187 		adapter->erp_low_mem_count--;
1188 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1189 	}
1190 
1191 	list_del(&erp_action->list);
1192 	zfcp_dbf_rec_run("eractd1", erp_action);
1193 
1194 	switch (erp_action->action) {
1195 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1196 		zfcp_sdev = sdev_to_zfcp(erp_action->sdev);
1197 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1198 				  &zfcp_sdev->status);
1199 		break;
1200 
1201 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1202 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1203 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1204 				  &erp_action->port->status);
1205 		break;
1206 
1207 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1208 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1209 				  &erp_action->adapter->status);
1210 		break;
1211 	}
1212 }
1213 
1214 /**
1215  * zfcp_erp_try_rport_unblock - unblock rport if no more/new recovery
1216  * @port: zfcp_port whose fc_rport we should try to unblock
1217  */
1218 static void zfcp_erp_try_rport_unblock(struct zfcp_port *port)
1219 {
1220 	unsigned long flags;
1221 	struct zfcp_adapter *adapter = port->adapter;
1222 	int port_status;
1223 	struct Scsi_Host *shost = adapter->scsi_host;
1224 	struct scsi_device *sdev;
1225 
1226 	write_lock_irqsave(&adapter->erp_lock, flags);
1227 	port_status = atomic_read(&port->status);
1228 	if ((port_status & ZFCP_STATUS_COMMON_UNBLOCKED)    == 0 ||
1229 	    (port_status & (ZFCP_STATUS_COMMON_ERP_INUSE |
1230 			    ZFCP_STATUS_COMMON_ERP_FAILED)) != 0) {
1231 		/* new ERP of severity >= port triggered elsewhere meanwhile or
1232 		 * local link down (adapter erp_failed but not clear unblock)
1233 		 */
1234 		zfcp_dbf_rec_run_lvl(4, "ertru_p", &port->erp_action);
1235 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1236 		return;
1237 	}
1238 	spin_lock(shost->host_lock);
1239 	__shost_for_each_device(sdev, shost) {
1240 		struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
1241 		int lun_status;
1242 
1243 		if (zsdev->port != port)
1244 			continue;
1245 		/* LUN under port of interest */
1246 		lun_status = atomic_read(&zsdev->status);
1247 		if ((lun_status & ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
1248 			continue; /* unblock rport despite failed LUNs */
1249 		/* LUN recovery not given up yet [maybe follow-up pending] */
1250 		if ((lun_status & ZFCP_STATUS_COMMON_UNBLOCKED) == 0 ||
1251 		    (lun_status & ZFCP_STATUS_COMMON_ERP_INUSE) != 0) {
1252 			/* LUN blocked:
1253 			 * not yet unblocked [LUN recovery pending]
1254 			 * or meanwhile blocked [new LUN recovery triggered]
1255 			 */
1256 			zfcp_dbf_rec_run_lvl(4, "ertru_l", &zsdev->erp_action);
1257 			spin_unlock(shost->host_lock);
1258 			write_unlock_irqrestore(&adapter->erp_lock, flags);
1259 			return;
1260 		}
1261 	}
1262 	/* now port has no child or all children have completed recovery,
1263 	 * and no ERP of severity >= port was meanwhile triggered elsewhere
1264 	 */
1265 	zfcp_scsi_schedule_rport_register(port);
1266 	spin_unlock(shost->host_lock);
1267 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1268 }
1269 
1270 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1271 {
1272 	struct zfcp_adapter *adapter = act->adapter;
1273 	struct zfcp_port *port = act->port;
1274 	struct scsi_device *sdev = act->sdev;
1275 
1276 	switch (act->action) {
1277 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1278 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
1279 			scsi_device_put(sdev);
1280 		zfcp_erp_try_rport_unblock(port);
1281 		break;
1282 
1283 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1284 		/* This switch case might also happen after a forced reopen
1285 		 * was successfully done and thus overwritten with a new
1286 		 * non-forced reopen at `ersfs_2'. In this case, we must not
1287 		 * do the clean-up of the non-forced version.
1288 		 */
1289 		if (act->step != ZFCP_ERP_STEP_UNINITIALIZED)
1290 			if (result == ZFCP_ERP_SUCCEEDED)
1291 				zfcp_erp_try_rport_unblock(port);
1292 		/* fall through */
1293 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1294 		put_device(&port->dev);
1295 		break;
1296 
1297 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1298 		if (result == ZFCP_ERP_SUCCEEDED) {
1299 			register_service_level(&adapter->service_level);
1300 			zfcp_fc_conditional_port_scan(adapter);
1301 			queue_work(adapter->work_queue, &adapter->ns_up_work);
1302 		} else
1303 			unregister_service_level(&adapter->service_level);
1304 
1305 		kref_put(&adapter->ref, zfcp_adapter_release);
1306 		break;
1307 	}
1308 }
1309 
1310 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1311 {
1312 	switch (erp_action->action) {
1313 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1314 		return zfcp_erp_adapter_strategy(erp_action);
1315 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1316 		return zfcp_erp_port_forced_strategy(erp_action);
1317 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1318 		return zfcp_erp_port_strategy(erp_action);
1319 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1320 		return zfcp_erp_lun_strategy(erp_action);
1321 	}
1322 	return ZFCP_ERP_FAILED;
1323 }
1324 
1325 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1326 {
1327 	int retval;
1328 	unsigned long flags;
1329 	struct zfcp_adapter *adapter = erp_action->adapter;
1330 
1331 	kref_get(&adapter->ref);
1332 
1333 	write_lock_irqsave(&adapter->erp_lock, flags);
1334 	zfcp_erp_strategy_check_fsfreq(erp_action);
1335 
1336 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1337 		zfcp_erp_action_dequeue(erp_action);
1338 		retval = ZFCP_ERP_DISMISSED;
1339 		goto unlock;
1340 	}
1341 
1342 	if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
1343 		retval = ZFCP_ERP_FAILED;
1344 		goto check_target;
1345 	}
1346 
1347 	zfcp_erp_action_to_running(erp_action);
1348 
1349 	/* no lock to allow for blocking operations */
1350 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1351 	retval = zfcp_erp_strategy_do_action(erp_action);
1352 	write_lock_irqsave(&adapter->erp_lock, flags);
1353 
1354 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1355 		retval = ZFCP_ERP_CONTINUES;
1356 
1357 	switch (retval) {
1358 	case ZFCP_ERP_NOMEM:
1359 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1360 			++adapter->erp_low_mem_count;
1361 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1362 		}
1363 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1364 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1");
1365 		else {
1366 			zfcp_erp_strategy_memwait(erp_action);
1367 			retval = ZFCP_ERP_CONTINUES;
1368 		}
1369 		goto unlock;
1370 
1371 	case ZFCP_ERP_CONTINUES:
1372 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1373 			--adapter->erp_low_mem_count;
1374 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1375 		}
1376 		goto unlock;
1377 	}
1378 
1379 check_target:
1380 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1381 	zfcp_erp_action_dequeue(erp_action);
1382 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1383 	if (retval == ZFCP_ERP_EXIT)
1384 		goto unlock;
1385 	if (retval == ZFCP_ERP_SUCCEEDED)
1386 		zfcp_erp_strategy_followup_success(erp_action);
1387 	if (retval == ZFCP_ERP_FAILED)
1388 		zfcp_erp_strategy_followup_failed(erp_action);
1389 
1390  unlock:
1391 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1392 
1393 	if (retval != ZFCP_ERP_CONTINUES)
1394 		zfcp_erp_action_cleanup(erp_action, retval);
1395 
1396 	kref_put(&adapter->ref, zfcp_adapter_release);
1397 	return retval;
1398 }
1399 
1400 static int zfcp_erp_thread(void *data)
1401 {
1402 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1403 	struct list_head *next;
1404 	struct zfcp_erp_action *act;
1405 	unsigned long flags;
1406 
1407 	for (;;) {
1408 		wait_event_interruptible(adapter->erp_ready_wq,
1409 			   !list_empty(&adapter->erp_ready_head) ||
1410 			   kthread_should_stop());
1411 
1412 		if (kthread_should_stop())
1413 			break;
1414 
1415 		write_lock_irqsave(&adapter->erp_lock, flags);
1416 		next = adapter->erp_ready_head.next;
1417 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1418 
1419 		if (next != &adapter->erp_ready_head) {
1420 			act = list_entry(next, struct zfcp_erp_action, list);
1421 
1422 			/* there is more to come after dismission, no notify */
1423 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1424 				zfcp_erp_wakeup(adapter);
1425 		}
1426 	}
1427 
1428 	return 0;
1429 }
1430 
1431 /**
1432  * zfcp_erp_thread_setup - Start ERP thread for adapter
1433  * @adapter: Adapter to start the ERP thread for
1434  *
1435  * Returns 0 on success or error code from kernel_thread()
1436  */
1437 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1438 {
1439 	struct task_struct *thread;
1440 
1441 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1442 			     dev_name(&adapter->ccw_device->dev));
1443 	if (IS_ERR(thread)) {
1444 		dev_err(&adapter->ccw_device->dev,
1445 			"Creating an ERP thread for the FCP device failed.\n");
1446 		return PTR_ERR(thread);
1447 	}
1448 
1449 	adapter->erp_thread = thread;
1450 	return 0;
1451 }
1452 
1453 /**
1454  * zfcp_erp_thread_kill - Stop ERP thread.
1455  * @adapter: Adapter where the ERP thread should be stopped.
1456  *
1457  * The caller of this routine ensures that the specified adapter has
1458  * been shut down and that this operation has been completed. Thus,
1459  * there are no pending erp_actions which would need to be handled
1460  * here.
1461  */
1462 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1463 {
1464 	kthread_stop(adapter->erp_thread);
1465 	adapter->erp_thread = NULL;
1466 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1467 	WARN_ON(!list_empty(&adapter->erp_running_head));
1468 }
1469 
1470 /**
1471  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1472  * @adapter: adapter for which to wait for completion of its error recovery
1473  */
1474 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1475 {
1476 	wait_event(adapter->erp_done_wqh,
1477 		   !(atomic_read(&adapter->status) &
1478 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1479 }
1480 
1481 /**
1482  * zfcp_erp_set_adapter_status - set adapter status bits
1483  * @adapter: adapter to change the status
1484  * @mask: status bits to change
1485  *
1486  * Changes in common status bits are propagated to attached ports and LUNs.
1487  */
1488 void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1489 {
1490 	struct zfcp_port *port;
1491 	struct scsi_device *sdev;
1492 	unsigned long flags;
1493 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1494 
1495 	atomic_or(mask, &adapter->status);
1496 
1497 	if (!common_mask)
1498 		return;
1499 
1500 	read_lock_irqsave(&adapter->port_list_lock, flags);
1501 	list_for_each_entry(port, &adapter->port_list, list)
1502 		atomic_or(common_mask, &port->status);
1503 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1504 
1505 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1506 	__shost_for_each_device(sdev, adapter->scsi_host)
1507 		atomic_or(common_mask, &sdev_to_zfcp(sdev)->status);
1508 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1509 }
1510 
1511 /**
1512  * zfcp_erp_clear_adapter_status - clear adapter status bits
1513  * @adapter: adapter to change the status
1514  * @mask: status bits to change
1515  *
1516  * Changes in common status bits are propagated to attached ports and LUNs.
1517  */
1518 void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1519 {
1520 	struct zfcp_port *port;
1521 	struct scsi_device *sdev;
1522 	unsigned long flags;
1523 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1524 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1525 
1526 	atomic_andnot(mask, &adapter->status);
1527 
1528 	if (!common_mask)
1529 		return;
1530 
1531 	if (clear_counter)
1532 		atomic_set(&adapter->erp_counter, 0);
1533 
1534 	read_lock_irqsave(&adapter->port_list_lock, flags);
1535 	list_for_each_entry(port, &adapter->port_list, list) {
1536 		atomic_andnot(common_mask, &port->status);
1537 		if (clear_counter)
1538 			atomic_set(&port->erp_counter, 0);
1539 	}
1540 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1541 
1542 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1543 	__shost_for_each_device(sdev, adapter->scsi_host) {
1544 		atomic_andnot(common_mask, &sdev_to_zfcp(sdev)->status);
1545 		if (clear_counter)
1546 			atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1547 	}
1548 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1549 }
1550 
1551 /**
1552  * zfcp_erp_set_port_status - set port status bits
1553  * @port: port to change the status
1554  * @mask: status bits to change
1555  *
1556  * Changes in common status bits are propagated to attached LUNs.
1557  */
1558 void zfcp_erp_set_port_status(struct zfcp_port *port, u32 mask)
1559 {
1560 	struct scsi_device *sdev;
1561 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1562 	unsigned long flags;
1563 
1564 	atomic_or(mask, &port->status);
1565 
1566 	if (!common_mask)
1567 		return;
1568 
1569 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1570 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1571 		if (sdev_to_zfcp(sdev)->port == port)
1572 			atomic_or(common_mask,
1573 					&sdev_to_zfcp(sdev)->status);
1574 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1575 }
1576 
1577 /**
1578  * zfcp_erp_clear_port_status - clear port status bits
1579  * @port: adapter to change the status
1580  * @mask: status bits to change
1581  *
1582  * Changes in common status bits are propagated to attached LUNs.
1583  */
1584 void zfcp_erp_clear_port_status(struct zfcp_port *port, u32 mask)
1585 {
1586 	struct scsi_device *sdev;
1587 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1588 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1589 	unsigned long flags;
1590 
1591 	atomic_andnot(mask, &port->status);
1592 
1593 	if (!common_mask)
1594 		return;
1595 
1596 	if (clear_counter)
1597 		atomic_set(&port->erp_counter, 0);
1598 
1599 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1600 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1601 		if (sdev_to_zfcp(sdev)->port == port) {
1602 			atomic_andnot(common_mask,
1603 					  &sdev_to_zfcp(sdev)->status);
1604 			if (clear_counter)
1605 				atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1606 		}
1607 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1608 }
1609 
1610 /**
1611  * zfcp_erp_set_lun_status - set lun status bits
1612  * @sdev: SCSI device / lun to set the status bits
1613  * @mask: status bits to change
1614  */
1615 void zfcp_erp_set_lun_status(struct scsi_device *sdev, u32 mask)
1616 {
1617 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1618 
1619 	atomic_or(mask, &zfcp_sdev->status);
1620 }
1621 
1622 /**
1623  * zfcp_erp_clear_lun_status - clear lun status bits
1624  * @sdev: SCSi device / lun to clear the status bits
1625  * @mask: status bits to change
1626  */
1627 void zfcp_erp_clear_lun_status(struct scsi_device *sdev, u32 mask)
1628 {
1629 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1630 
1631 	atomic_andnot(mask, &zfcp_sdev->status);
1632 
1633 	if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1634 		atomic_set(&zfcp_sdev->erp_counter, 0);
1635 }
1636 
1637