xref: /linux/drivers/s390/scsi/zfcp_erp.c (revision 33dea5aae0320345af26ae9aba0894a930e0d4ec)
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(unsigned long data)
568 {
569 	struct zfcp_erp_action *act = (struct zfcp_erp_action *) data;
570 	zfcp_erp_notify(act, ZFCP_STATUS_ERP_TIMEDOUT);
571 }
572 
573 static void zfcp_erp_memwait_handler(unsigned long data)
574 {
575 	zfcp_erp_notify((struct zfcp_erp_action *)data, 0);
576 }
577 
578 static void zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
579 {
580 	setup_timer(&erp_action->timer, zfcp_erp_memwait_handler,
581 		    (unsigned long) erp_action);
582 	erp_action->timer.expires = jiffies + HZ;
583 	add_timer(&erp_action->timer);
584 }
585 
586 static void _zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter,
587 				      int clear, char *id)
588 {
589 	struct zfcp_port *port;
590 
591 	read_lock(&adapter->port_list_lock);
592 	list_for_each_entry(port, &adapter->port_list, list)
593 		_zfcp_erp_port_reopen(port, clear, id);
594 	read_unlock(&adapter->port_list_lock);
595 }
596 
597 static void _zfcp_erp_lun_reopen_all(struct zfcp_port *port, int clear,
598 				     char *id)
599 {
600 	struct scsi_device *sdev;
601 
602 	spin_lock(port->adapter->scsi_host->host_lock);
603 	__shost_for_each_device(sdev, port->adapter->scsi_host)
604 		if (sdev_to_zfcp(sdev)->port == port)
605 			_zfcp_erp_lun_reopen(sdev, clear, id, 0);
606 	spin_unlock(port->adapter->scsi_host->host_lock);
607 }
608 
609 static void zfcp_erp_strategy_followup_failed(struct zfcp_erp_action *act)
610 {
611 	switch (act->action) {
612 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
613 		_zfcp_erp_adapter_reopen(act->adapter, 0, "ersff_1");
614 		break;
615 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
616 		_zfcp_erp_port_forced_reopen(act->port, 0, "ersff_2");
617 		break;
618 	case ZFCP_ERP_ACTION_REOPEN_PORT:
619 		_zfcp_erp_port_reopen(act->port, 0, "ersff_3");
620 		break;
621 	case ZFCP_ERP_ACTION_REOPEN_LUN:
622 		_zfcp_erp_lun_reopen(act->sdev, 0, "ersff_4", 0);
623 		break;
624 	}
625 }
626 
627 static void zfcp_erp_strategy_followup_success(struct zfcp_erp_action *act)
628 {
629 	switch (act->action) {
630 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
631 		_zfcp_erp_port_reopen_all(act->adapter, 0, "ersfs_1");
632 		break;
633 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
634 		_zfcp_erp_port_reopen(act->port, 0, "ersfs_2");
635 		break;
636 	case ZFCP_ERP_ACTION_REOPEN_PORT:
637 		_zfcp_erp_lun_reopen_all(act->port, 0, "ersfs_3");
638 		break;
639 	}
640 }
641 
642 static void zfcp_erp_wakeup(struct zfcp_adapter *adapter)
643 {
644 	unsigned long flags;
645 
646 	read_lock_irqsave(&adapter->erp_lock, flags);
647 	if (list_empty(&adapter->erp_ready_head) &&
648 	    list_empty(&adapter->erp_running_head)) {
649 			atomic_andnot(ZFCP_STATUS_ADAPTER_ERP_PENDING,
650 					  &adapter->status);
651 			wake_up(&adapter->erp_done_wqh);
652 	}
653 	read_unlock_irqrestore(&adapter->erp_lock, flags);
654 }
655 
656 static void zfcp_erp_enqueue_ptp_port(struct zfcp_adapter *adapter)
657 {
658 	struct zfcp_port *port;
659 	port = zfcp_port_enqueue(adapter, adapter->peer_wwpn, 0,
660 				 adapter->peer_d_id);
661 	if (IS_ERR(port)) /* error or port already attached */
662 		return;
663 	_zfcp_erp_port_reopen(port, 0, "ereptp1");
664 }
665 
666 static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
667 {
668 	int retries;
669 	int sleep = 1;
670 	struct zfcp_adapter *adapter = erp_action->adapter;
671 
672 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
673 
674 	for (retries = 7; retries; retries--) {
675 		atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
676 				  &adapter->status);
677 		write_lock_irq(&adapter->erp_lock);
678 		zfcp_erp_action_to_running(erp_action);
679 		write_unlock_irq(&adapter->erp_lock);
680 		if (zfcp_fsf_exchange_config_data(erp_action)) {
681 			atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
682 					  &adapter->status);
683 			return ZFCP_ERP_FAILED;
684 		}
685 
686 		wait_event(adapter->erp_ready_wq,
687 			   !list_empty(&adapter->erp_ready_head));
688 		if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
689 			break;
690 
691 		if (!(atomic_read(&adapter->status) &
692 		      ZFCP_STATUS_ADAPTER_HOST_CON_INIT))
693 			break;
694 
695 		ssleep(sleep);
696 		sleep *= 2;
697 	}
698 
699 	atomic_andnot(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
700 			  &adapter->status);
701 
702 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
703 		return ZFCP_ERP_FAILED;
704 
705 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
706 		zfcp_erp_enqueue_ptp_port(adapter);
707 
708 	return ZFCP_ERP_SUCCEEDED;
709 }
710 
711 static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
712 {
713 	int ret;
714 	struct zfcp_adapter *adapter = act->adapter;
715 
716 	write_lock_irq(&adapter->erp_lock);
717 	zfcp_erp_action_to_running(act);
718 	write_unlock_irq(&adapter->erp_lock);
719 
720 	ret = zfcp_fsf_exchange_port_data(act);
721 	if (ret == -EOPNOTSUPP)
722 		return ZFCP_ERP_SUCCEEDED;
723 	if (ret)
724 		return ZFCP_ERP_FAILED;
725 
726 	zfcp_dbf_rec_run("erasox1", act);
727 	wait_event(adapter->erp_ready_wq,
728 		   !list_empty(&adapter->erp_ready_head));
729 	zfcp_dbf_rec_run("erasox2", act);
730 	if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
731 		return ZFCP_ERP_FAILED;
732 
733 	return ZFCP_ERP_SUCCEEDED;
734 }
735 
736 static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
737 {
738 	if (zfcp_erp_adapter_strat_fsf_xconf(act) == ZFCP_ERP_FAILED)
739 		return ZFCP_ERP_FAILED;
740 
741 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
742 		return ZFCP_ERP_FAILED;
743 
744 	if (mempool_resize(act->adapter->pool.sr_data,
745 			   act->adapter->stat_read_buf_num))
746 		return ZFCP_ERP_FAILED;
747 
748 	if (mempool_resize(act->adapter->pool.status_read_req,
749 			   act->adapter->stat_read_buf_num))
750 		return ZFCP_ERP_FAILED;
751 
752 	atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
753 	if (zfcp_status_read_refill(act->adapter))
754 		return ZFCP_ERP_FAILED;
755 
756 	return ZFCP_ERP_SUCCEEDED;
757 }
758 
759 static void zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *act)
760 {
761 	struct zfcp_adapter *adapter = act->adapter;
762 
763 	/* close queues to ensure that buffers are not accessed by adapter */
764 	zfcp_qdio_close(adapter->qdio);
765 	zfcp_fsf_req_dismiss_all(adapter);
766 	adapter->fsf_req_seq_no = 0;
767 	zfcp_fc_wka_ports_force_offline(adapter->gs);
768 	/* all ports and LUNs are closed */
769 	zfcp_erp_clear_adapter_status(adapter, ZFCP_STATUS_COMMON_OPEN);
770 
771 	atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
772 			  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
773 }
774 
775 static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *act)
776 {
777 	struct zfcp_adapter *adapter = act->adapter;
778 
779 	if (zfcp_qdio_open(adapter->qdio)) {
780 		atomic_andnot(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
781 				  ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED,
782 				  &adapter->status);
783 		return ZFCP_ERP_FAILED;
784 	}
785 
786 	if (zfcp_erp_adapter_strategy_open_fsf(act)) {
787 		zfcp_erp_adapter_strategy_close(act);
788 		return ZFCP_ERP_FAILED;
789 	}
790 
791 	atomic_or(ZFCP_STATUS_COMMON_OPEN, &adapter->status);
792 
793 	return ZFCP_ERP_SUCCEEDED;
794 }
795 
796 static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *act)
797 {
798 	struct zfcp_adapter *adapter = act->adapter;
799 
800 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_OPEN) {
801 		zfcp_erp_adapter_strategy_close(act);
802 		if (act->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
803 			return ZFCP_ERP_EXIT;
804 	}
805 
806 	if (zfcp_erp_adapter_strategy_open(act)) {
807 		ssleep(8);
808 		return ZFCP_ERP_FAILED;
809 	}
810 
811 	return ZFCP_ERP_SUCCEEDED;
812 }
813 
814 static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
815 {
816 	int retval;
817 
818 	retval = zfcp_fsf_close_physical_port(act);
819 	if (retval == -ENOMEM)
820 		return ZFCP_ERP_NOMEM;
821 	act->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
822 	if (retval)
823 		return ZFCP_ERP_FAILED;
824 
825 	return ZFCP_ERP_CONTINUES;
826 }
827 
828 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
829 {
830 	struct zfcp_port *port = erp_action->port;
831 	int status = atomic_read(&port->status);
832 
833 	switch (erp_action->step) {
834 	case ZFCP_ERP_STEP_UNINITIALIZED:
835 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
836 		    (status & ZFCP_STATUS_COMMON_OPEN))
837 			return zfcp_erp_port_forced_strategy_close(erp_action);
838 		else
839 			return ZFCP_ERP_FAILED;
840 
841 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
842 		if (!(status & ZFCP_STATUS_PORT_PHYS_OPEN))
843 			return ZFCP_ERP_SUCCEEDED;
844 	}
845 	return ZFCP_ERP_FAILED;
846 }
847 
848 static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
849 {
850 	int retval;
851 
852 	retval = zfcp_fsf_close_port(erp_action);
853 	if (retval == -ENOMEM)
854 		return ZFCP_ERP_NOMEM;
855 	erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
856 	if (retval)
857 		return ZFCP_ERP_FAILED;
858 	return ZFCP_ERP_CONTINUES;
859 }
860 
861 static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
862 {
863 	int retval;
864 
865 	retval = zfcp_fsf_open_port(erp_action);
866 	if (retval == -ENOMEM)
867 		return ZFCP_ERP_NOMEM;
868 	erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
869 	if (retval)
870 		return ZFCP_ERP_FAILED;
871 	return ZFCP_ERP_CONTINUES;
872 }
873 
874 static int zfcp_erp_open_ptp_port(struct zfcp_erp_action *act)
875 {
876 	struct zfcp_adapter *adapter = act->adapter;
877 	struct zfcp_port *port = act->port;
878 
879 	if (port->wwpn != adapter->peer_wwpn) {
880 		zfcp_erp_set_port_status(port, ZFCP_STATUS_COMMON_ERP_FAILED);
881 		return ZFCP_ERP_FAILED;
882 	}
883 	port->d_id = adapter->peer_d_id;
884 	return zfcp_erp_port_strategy_open_port(act);
885 }
886 
887 static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *act)
888 {
889 	struct zfcp_adapter *adapter = act->adapter;
890 	struct zfcp_port *port = act->port;
891 	int p_status = atomic_read(&port->status);
892 
893 	switch (act->step) {
894 	case ZFCP_ERP_STEP_UNINITIALIZED:
895 	case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
896 	case ZFCP_ERP_STEP_PORT_CLOSING:
897 		if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
898 			return zfcp_erp_open_ptp_port(act);
899 		if (!port->d_id) {
900 			zfcp_fc_trigger_did_lookup(port);
901 			return ZFCP_ERP_EXIT;
902 		}
903 		return zfcp_erp_port_strategy_open_port(act);
904 
905 	case ZFCP_ERP_STEP_PORT_OPENING:
906 		/* D_ID might have changed during open */
907 		if (p_status & ZFCP_STATUS_COMMON_OPEN) {
908 			if (!port->d_id) {
909 				zfcp_fc_trigger_did_lookup(port);
910 				return ZFCP_ERP_EXIT;
911 			}
912 			return ZFCP_ERP_SUCCEEDED;
913 		}
914 		if (port->d_id && !(p_status & ZFCP_STATUS_COMMON_NOESC)) {
915 			port->d_id = 0;
916 			return ZFCP_ERP_FAILED;
917 		}
918 		/* fall through otherwise */
919 	}
920 	return ZFCP_ERP_FAILED;
921 }
922 
923 static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
924 {
925 	struct zfcp_port *port = erp_action->port;
926 	int p_status = atomic_read(&port->status);
927 
928 	if ((p_status & ZFCP_STATUS_COMMON_NOESC) &&
929 	    !(p_status & ZFCP_STATUS_COMMON_OPEN))
930 		goto close_init_done;
931 
932 	switch (erp_action->step) {
933 	case ZFCP_ERP_STEP_UNINITIALIZED:
934 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
935 			return zfcp_erp_port_strategy_close(erp_action);
936 		break;
937 
938 	case ZFCP_ERP_STEP_PORT_CLOSING:
939 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
940 			return ZFCP_ERP_FAILED;
941 		break;
942 	}
943 
944 close_init_done:
945 	if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
946 		return ZFCP_ERP_EXIT;
947 
948 	return zfcp_erp_port_strategy_open_common(erp_action);
949 }
950 
951 static void zfcp_erp_lun_strategy_clearstati(struct scsi_device *sdev)
952 {
953 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
954 
955 	atomic_andnot(ZFCP_STATUS_COMMON_ACCESS_DENIED,
956 			  &zfcp_sdev->status);
957 }
958 
959 static int zfcp_erp_lun_strategy_close(struct zfcp_erp_action *erp_action)
960 {
961 	int retval = zfcp_fsf_close_lun(erp_action);
962 	if (retval == -ENOMEM)
963 		return ZFCP_ERP_NOMEM;
964 	erp_action->step = ZFCP_ERP_STEP_LUN_CLOSING;
965 	if (retval)
966 		return ZFCP_ERP_FAILED;
967 	return ZFCP_ERP_CONTINUES;
968 }
969 
970 static int zfcp_erp_lun_strategy_open(struct zfcp_erp_action *erp_action)
971 {
972 	int retval = zfcp_fsf_open_lun(erp_action);
973 	if (retval == -ENOMEM)
974 		return ZFCP_ERP_NOMEM;
975 	erp_action->step = ZFCP_ERP_STEP_LUN_OPENING;
976 	if (retval)
977 		return  ZFCP_ERP_FAILED;
978 	return ZFCP_ERP_CONTINUES;
979 }
980 
981 static int zfcp_erp_lun_strategy(struct zfcp_erp_action *erp_action)
982 {
983 	struct scsi_device *sdev = erp_action->sdev;
984 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
985 
986 	switch (erp_action->step) {
987 	case ZFCP_ERP_STEP_UNINITIALIZED:
988 		zfcp_erp_lun_strategy_clearstati(sdev);
989 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
990 			return zfcp_erp_lun_strategy_close(erp_action);
991 		/* already closed, fall through */
992 	case ZFCP_ERP_STEP_LUN_CLOSING:
993 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
994 			return ZFCP_ERP_FAILED;
995 		if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
996 			return ZFCP_ERP_EXIT;
997 		return zfcp_erp_lun_strategy_open(erp_action);
998 
999 	case ZFCP_ERP_STEP_LUN_OPENING:
1000 		if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
1001 			return ZFCP_ERP_SUCCEEDED;
1002 	}
1003 	return ZFCP_ERP_FAILED;
1004 }
1005 
1006 static int zfcp_erp_strategy_check_lun(struct scsi_device *sdev, int result)
1007 {
1008 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1009 
1010 	switch (result) {
1011 	case ZFCP_ERP_SUCCEEDED :
1012 		atomic_set(&zfcp_sdev->erp_counter, 0);
1013 		zfcp_erp_lun_unblock(sdev);
1014 		break;
1015 	case ZFCP_ERP_FAILED :
1016 		atomic_inc(&zfcp_sdev->erp_counter);
1017 		if (atomic_read(&zfcp_sdev->erp_counter) > ZFCP_MAX_ERPS) {
1018 			dev_err(&zfcp_sdev->port->adapter->ccw_device->dev,
1019 				"ERP failed for LUN 0x%016Lx on "
1020 				"port 0x%016Lx\n",
1021 				(unsigned long long)zfcp_scsi_dev_lun(sdev),
1022 				(unsigned long long)zfcp_sdev->port->wwpn);
1023 			zfcp_erp_set_lun_status(sdev,
1024 						ZFCP_STATUS_COMMON_ERP_FAILED);
1025 		}
1026 		break;
1027 	}
1028 
1029 	if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1030 		zfcp_erp_lun_block(sdev, 0);
1031 		result = ZFCP_ERP_EXIT;
1032 	}
1033 	return result;
1034 }
1035 
1036 static int zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
1037 {
1038 	switch (result) {
1039 	case ZFCP_ERP_SUCCEEDED :
1040 		atomic_set(&port->erp_counter, 0);
1041 		zfcp_erp_port_unblock(port);
1042 		break;
1043 
1044 	case ZFCP_ERP_FAILED :
1045 		if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC) {
1046 			zfcp_erp_port_block(port, 0);
1047 			result = ZFCP_ERP_EXIT;
1048 		}
1049 		atomic_inc(&port->erp_counter);
1050 		if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS) {
1051 			dev_err(&port->adapter->ccw_device->dev,
1052 				"ERP failed for remote port 0x%016Lx\n",
1053 				(unsigned long long)port->wwpn);
1054 			zfcp_erp_set_port_status(port,
1055 					 ZFCP_STATUS_COMMON_ERP_FAILED);
1056 		}
1057 		break;
1058 	}
1059 
1060 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1061 		zfcp_erp_port_block(port, 0);
1062 		result = ZFCP_ERP_EXIT;
1063 	}
1064 	return result;
1065 }
1066 
1067 static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter,
1068 					   int result)
1069 {
1070 	switch (result) {
1071 	case ZFCP_ERP_SUCCEEDED :
1072 		atomic_set(&adapter->erp_counter, 0);
1073 		zfcp_erp_adapter_unblock(adapter);
1074 		break;
1075 
1076 	case ZFCP_ERP_FAILED :
1077 		atomic_inc(&adapter->erp_counter);
1078 		if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS) {
1079 			dev_err(&adapter->ccw_device->dev,
1080 				"ERP cannot recover an error "
1081 				"on the FCP device\n");
1082 			zfcp_erp_set_adapter_status(adapter,
1083 					    ZFCP_STATUS_COMMON_ERP_FAILED);
1084 		}
1085 		break;
1086 	}
1087 
1088 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
1089 		zfcp_erp_adapter_block(adapter, 0);
1090 		result = ZFCP_ERP_EXIT;
1091 	}
1092 	return result;
1093 }
1094 
1095 static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action,
1096 					  int result)
1097 {
1098 	struct zfcp_adapter *adapter = erp_action->adapter;
1099 	struct zfcp_port *port = erp_action->port;
1100 	struct scsi_device *sdev = erp_action->sdev;
1101 
1102 	switch (erp_action->action) {
1103 
1104 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1105 		result = zfcp_erp_strategy_check_lun(sdev, result);
1106 		break;
1107 
1108 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1109 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1110 		result = zfcp_erp_strategy_check_port(port, result);
1111 		break;
1112 
1113 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1114 		result = zfcp_erp_strategy_check_adapter(adapter, result);
1115 		break;
1116 	}
1117 	return result;
1118 }
1119 
1120 static int zfcp_erp_strat_change_det(atomic_t *target_status, u32 erp_status)
1121 {
1122 	int status = atomic_read(target_status);
1123 
1124 	if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
1125 	    (erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1126 		return 1; /* take it online */
1127 
1128 	if (!(status & ZFCP_STATUS_COMMON_RUNNING) &&
1129 	    !(erp_status & ZFCP_STATUS_ERP_CLOSE_ONLY))
1130 		return 1; /* take it offline */
1131 
1132 	return 0;
1133 }
1134 
1135 static int zfcp_erp_strategy_statechange(struct zfcp_erp_action *act, int ret)
1136 {
1137 	int action = act->action;
1138 	struct zfcp_adapter *adapter = act->adapter;
1139 	struct zfcp_port *port = act->port;
1140 	struct scsi_device *sdev = act->sdev;
1141 	struct zfcp_scsi_dev *zfcp_sdev;
1142 	u32 erp_status = act->status;
1143 
1144 	switch (action) {
1145 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1146 		if (zfcp_erp_strat_change_det(&adapter->status, erp_status)) {
1147 			_zfcp_erp_adapter_reopen(adapter,
1148 						 ZFCP_STATUS_COMMON_ERP_FAILED,
1149 						 "ersscg1");
1150 			return ZFCP_ERP_EXIT;
1151 		}
1152 		break;
1153 
1154 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1155 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1156 		if (zfcp_erp_strat_change_det(&port->status, erp_status)) {
1157 			_zfcp_erp_port_reopen(port,
1158 					      ZFCP_STATUS_COMMON_ERP_FAILED,
1159 					      "ersscg2");
1160 			return ZFCP_ERP_EXIT;
1161 		}
1162 		break;
1163 
1164 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1165 		zfcp_sdev = sdev_to_zfcp(sdev);
1166 		if (zfcp_erp_strat_change_det(&zfcp_sdev->status, erp_status)) {
1167 			_zfcp_erp_lun_reopen(sdev,
1168 					     ZFCP_STATUS_COMMON_ERP_FAILED,
1169 					     "ersscg3", 0);
1170 			return ZFCP_ERP_EXIT;
1171 		}
1172 		break;
1173 	}
1174 	return ret;
1175 }
1176 
1177 static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
1178 {
1179 	struct zfcp_adapter *adapter = erp_action->adapter;
1180 	struct zfcp_scsi_dev *zfcp_sdev;
1181 
1182 	adapter->erp_total_count--;
1183 	if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1184 		adapter->erp_low_mem_count--;
1185 		erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1186 	}
1187 
1188 	list_del(&erp_action->list);
1189 	zfcp_dbf_rec_run("eractd1", erp_action);
1190 
1191 	switch (erp_action->action) {
1192 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1193 		zfcp_sdev = sdev_to_zfcp(erp_action->sdev);
1194 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1195 				  &zfcp_sdev->status);
1196 		break;
1197 
1198 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1199 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1200 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1201 				  &erp_action->port->status);
1202 		break;
1203 
1204 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1205 		atomic_andnot(ZFCP_STATUS_COMMON_ERP_INUSE,
1206 				  &erp_action->adapter->status);
1207 		break;
1208 	}
1209 }
1210 
1211 /**
1212  * zfcp_erp_try_rport_unblock - unblock rport if no more/new recovery
1213  * @port: zfcp_port whose fc_rport we should try to unblock
1214  */
1215 static void zfcp_erp_try_rport_unblock(struct zfcp_port *port)
1216 {
1217 	unsigned long flags;
1218 	struct zfcp_adapter *adapter = port->adapter;
1219 	int port_status;
1220 	struct Scsi_Host *shost = adapter->scsi_host;
1221 	struct scsi_device *sdev;
1222 
1223 	write_lock_irqsave(&adapter->erp_lock, flags);
1224 	port_status = atomic_read(&port->status);
1225 	if ((port_status & ZFCP_STATUS_COMMON_UNBLOCKED)    == 0 ||
1226 	    (port_status & (ZFCP_STATUS_COMMON_ERP_INUSE |
1227 			    ZFCP_STATUS_COMMON_ERP_FAILED)) != 0) {
1228 		/* new ERP of severity >= port triggered elsewhere meanwhile or
1229 		 * local link down (adapter erp_failed but not clear unblock)
1230 		 */
1231 		zfcp_dbf_rec_run_lvl(4, "ertru_p", &port->erp_action);
1232 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1233 		return;
1234 	}
1235 	spin_lock(shost->host_lock);
1236 	__shost_for_each_device(sdev, shost) {
1237 		struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
1238 		int lun_status;
1239 
1240 		if (zsdev->port != port)
1241 			continue;
1242 		/* LUN under port of interest */
1243 		lun_status = atomic_read(&zsdev->status);
1244 		if ((lun_status & ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
1245 			continue; /* unblock rport despite failed LUNs */
1246 		/* LUN recovery not given up yet [maybe follow-up pending] */
1247 		if ((lun_status & ZFCP_STATUS_COMMON_UNBLOCKED) == 0 ||
1248 		    (lun_status & ZFCP_STATUS_COMMON_ERP_INUSE) != 0) {
1249 			/* LUN blocked:
1250 			 * not yet unblocked [LUN recovery pending]
1251 			 * or meanwhile blocked [new LUN recovery triggered]
1252 			 */
1253 			zfcp_dbf_rec_run_lvl(4, "ertru_l", &zsdev->erp_action);
1254 			spin_unlock(shost->host_lock);
1255 			write_unlock_irqrestore(&adapter->erp_lock, flags);
1256 			return;
1257 		}
1258 	}
1259 	/* now port has no child or all children have completed recovery,
1260 	 * and no ERP of severity >= port was meanwhile triggered elsewhere
1261 	 */
1262 	zfcp_scsi_schedule_rport_register(port);
1263 	spin_unlock(shost->host_lock);
1264 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1265 }
1266 
1267 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
1268 {
1269 	struct zfcp_adapter *adapter = act->adapter;
1270 	struct zfcp_port *port = act->port;
1271 	struct scsi_device *sdev = act->sdev;
1272 
1273 	switch (act->action) {
1274 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1275 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
1276 			scsi_device_put(sdev);
1277 		zfcp_erp_try_rport_unblock(port);
1278 		break;
1279 
1280 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1281 		/* This switch case might also happen after a forced reopen
1282 		 * was successfully done and thus overwritten with a new
1283 		 * non-forced reopen at `ersfs_2'. In this case, we must not
1284 		 * do the clean-up of the non-forced version.
1285 		 */
1286 		if (act->step != ZFCP_ERP_STEP_UNINITIALIZED)
1287 			if (result == ZFCP_ERP_SUCCEEDED)
1288 				zfcp_erp_try_rport_unblock(port);
1289 		/* fall through */
1290 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1291 		put_device(&port->dev);
1292 		break;
1293 
1294 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1295 		if (result == ZFCP_ERP_SUCCEEDED) {
1296 			register_service_level(&adapter->service_level);
1297 			zfcp_fc_conditional_port_scan(adapter);
1298 			queue_work(adapter->work_queue, &adapter->ns_up_work);
1299 		} else
1300 			unregister_service_level(&adapter->service_level);
1301 
1302 		kref_put(&adapter->ref, zfcp_adapter_release);
1303 		break;
1304 	}
1305 }
1306 
1307 static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
1308 {
1309 	switch (erp_action->action) {
1310 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
1311 		return zfcp_erp_adapter_strategy(erp_action);
1312 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
1313 		return zfcp_erp_port_forced_strategy(erp_action);
1314 	case ZFCP_ERP_ACTION_REOPEN_PORT:
1315 		return zfcp_erp_port_strategy(erp_action);
1316 	case ZFCP_ERP_ACTION_REOPEN_LUN:
1317 		return zfcp_erp_lun_strategy(erp_action);
1318 	}
1319 	return ZFCP_ERP_FAILED;
1320 }
1321 
1322 static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
1323 {
1324 	int retval;
1325 	unsigned long flags;
1326 	struct zfcp_adapter *adapter = erp_action->adapter;
1327 
1328 	kref_get(&adapter->ref);
1329 
1330 	write_lock_irqsave(&adapter->erp_lock, flags);
1331 	zfcp_erp_strategy_check_fsfreq(erp_action);
1332 
1333 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
1334 		zfcp_erp_action_dequeue(erp_action);
1335 		retval = ZFCP_ERP_DISMISSED;
1336 		goto unlock;
1337 	}
1338 
1339 	if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
1340 		retval = ZFCP_ERP_FAILED;
1341 		goto check_target;
1342 	}
1343 
1344 	zfcp_erp_action_to_running(erp_action);
1345 
1346 	/* no lock to allow for blocking operations */
1347 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1348 	retval = zfcp_erp_strategy_do_action(erp_action);
1349 	write_lock_irqsave(&adapter->erp_lock, flags);
1350 
1351 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
1352 		retval = ZFCP_ERP_CONTINUES;
1353 
1354 	switch (retval) {
1355 	case ZFCP_ERP_NOMEM:
1356 		if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
1357 			++adapter->erp_low_mem_count;
1358 			erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
1359 		}
1360 		if (adapter->erp_total_count == adapter->erp_low_mem_count)
1361 			_zfcp_erp_adapter_reopen(adapter, 0, "erstgy1");
1362 		else {
1363 			zfcp_erp_strategy_memwait(erp_action);
1364 			retval = ZFCP_ERP_CONTINUES;
1365 		}
1366 		goto unlock;
1367 
1368 	case ZFCP_ERP_CONTINUES:
1369 		if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
1370 			--adapter->erp_low_mem_count;
1371 			erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
1372 		}
1373 		goto unlock;
1374 	}
1375 
1376 check_target:
1377 	retval = zfcp_erp_strategy_check_target(erp_action, retval);
1378 	zfcp_erp_action_dequeue(erp_action);
1379 	retval = zfcp_erp_strategy_statechange(erp_action, retval);
1380 	if (retval == ZFCP_ERP_EXIT)
1381 		goto unlock;
1382 	if (retval == ZFCP_ERP_SUCCEEDED)
1383 		zfcp_erp_strategy_followup_success(erp_action);
1384 	if (retval == ZFCP_ERP_FAILED)
1385 		zfcp_erp_strategy_followup_failed(erp_action);
1386 
1387  unlock:
1388 	write_unlock_irqrestore(&adapter->erp_lock, flags);
1389 
1390 	if (retval != ZFCP_ERP_CONTINUES)
1391 		zfcp_erp_action_cleanup(erp_action, retval);
1392 
1393 	kref_put(&adapter->ref, zfcp_adapter_release);
1394 	return retval;
1395 }
1396 
1397 static int zfcp_erp_thread(void *data)
1398 {
1399 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
1400 	struct list_head *next;
1401 	struct zfcp_erp_action *act;
1402 	unsigned long flags;
1403 
1404 	for (;;) {
1405 		wait_event_interruptible(adapter->erp_ready_wq,
1406 			   !list_empty(&adapter->erp_ready_head) ||
1407 			   kthread_should_stop());
1408 
1409 		if (kthread_should_stop())
1410 			break;
1411 
1412 		write_lock_irqsave(&adapter->erp_lock, flags);
1413 		next = adapter->erp_ready_head.next;
1414 		write_unlock_irqrestore(&adapter->erp_lock, flags);
1415 
1416 		if (next != &adapter->erp_ready_head) {
1417 			act = list_entry(next, struct zfcp_erp_action, list);
1418 
1419 			/* there is more to come after dismission, no notify */
1420 			if (zfcp_erp_strategy(act) != ZFCP_ERP_DISMISSED)
1421 				zfcp_erp_wakeup(adapter);
1422 		}
1423 	}
1424 
1425 	return 0;
1426 }
1427 
1428 /**
1429  * zfcp_erp_thread_setup - Start ERP thread for adapter
1430  * @adapter: Adapter to start the ERP thread for
1431  *
1432  * Returns 0 on success or error code from kernel_thread()
1433  */
1434 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
1435 {
1436 	struct task_struct *thread;
1437 
1438 	thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
1439 			     dev_name(&adapter->ccw_device->dev));
1440 	if (IS_ERR(thread)) {
1441 		dev_err(&adapter->ccw_device->dev,
1442 			"Creating an ERP thread for the FCP device failed.\n");
1443 		return PTR_ERR(thread);
1444 	}
1445 
1446 	adapter->erp_thread = thread;
1447 	return 0;
1448 }
1449 
1450 /**
1451  * zfcp_erp_thread_kill - Stop ERP thread.
1452  * @adapter: Adapter where the ERP thread should be stopped.
1453  *
1454  * The caller of this routine ensures that the specified adapter has
1455  * been shut down and that this operation has been completed. Thus,
1456  * there are no pending erp_actions which would need to be handled
1457  * here.
1458  */
1459 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
1460 {
1461 	kthread_stop(adapter->erp_thread);
1462 	adapter->erp_thread = NULL;
1463 	WARN_ON(!list_empty(&adapter->erp_ready_head));
1464 	WARN_ON(!list_empty(&adapter->erp_running_head));
1465 }
1466 
1467 /**
1468  * zfcp_erp_wait - wait for completion of error recovery on an adapter
1469  * @adapter: adapter for which to wait for completion of its error recovery
1470  */
1471 void zfcp_erp_wait(struct zfcp_adapter *adapter)
1472 {
1473 	wait_event(adapter->erp_done_wqh,
1474 		   !(atomic_read(&adapter->status) &
1475 			ZFCP_STATUS_ADAPTER_ERP_PENDING));
1476 }
1477 
1478 /**
1479  * zfcp_erp_set_adapter_status - set adapter status bits
1480  * @adapter: adapter to change the status
1481  * @mask: status bits to change
1482  *
1483  * Changes in common status bits are propagated to attached ports and LUNs.
1484  */
1485 void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1486 {
1487 	struct zfcp_port *port;
1488 	struct scsi_device *sdev;
1489 	unsigned long flags;
1490 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1491 
1492 	atomic_or(mask, &adapter->status);
1493 
1494 	if (!common_mask)
1495 		return;
1496 
1497 	read_lock_irqsave(&adapter->port_list_lock, flags);
1498 	list_for_each_entry(port, &adapter->port_list, list)
1499 		atomic_or(common_mask, &port->status);
1500 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1501 
1502 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1503 	__shost_for_each_device(sdev, adapter->scsi_host)
1504 		atomic_or(common_mask, &sdev_to_zfcp(sdev)->status);
1505 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1506 }
1507 
1508 /**
1509  * zfcp_erp_clear_adapter_status - clear adapter status bits
1510  * @adapter: adapter to change the status
1511  * @mask: status bits to change
1512  *
1513  * Changes in common status bits are propagated to attached ports and LUNs.
1514  */
1515 void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
1516 {
1517 	struct zfcp_port *port;
1518 	struct scsi_device *sdev;
1519 	unsigned long flags;
1520 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1521 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1522 
1523 	atomic_andnot(mask, &adapter->status);
1524 
1525 	if (!common_mask)
1526 		return;
1527 
1528 	if (clear_counter)
1529 		atomic_set(&adapter->erp_counter, 0);
1530 
1531 	read_lock_irqsave(&adapter->port_list_lock, flags);
1532 	list_for_each_entry(port, &adapter->port_list, list) {
1533 		atomic_andnot(common_mask, &port->status);
1534 		if (clear_counter)
1535 			atomic_set(&port->erp_counter, 0);
1536 	}
1537 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
1538 
1539 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
1540 	__shost_for_each_device(sdev, adapter->scsi_host) {
1541 		atomic_andnot(common_mask, &sdev_to_zfcp(sdev)->status);
1542 		if (clear_counter)
1543 			atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1544 	}
1545 	spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
1546 }
1547 
1548 /**
1549  * zfcp_erp_set_port_status - set port status bits
1550  * @port: port to change the status
1551  * @mask: status bits to change
1552  *
1553  * Changes in common status bits are propagated to attached LUNs.
1554  */
1555 void zfcp_erp_set_port_status(struct zfcp_port *port, u32 mask)
1556 {
1557 	struct scsi_device *sdev;
1558 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1559 	unsigned long flags;
1560 
1561 	atomic_or(mask, &port->status);
1562 
1563 	if (!common_mask)
1564 		return;
1565 
1566 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1567 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1568 		if (sdev_to_zfcp(sdev)->port == port)
1569 			atomic_or(common_mask,
1570 					&sdev_to_zfcp(sdev)->status);
1571 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1572 }
1573 
1574 /**
1575  * zfcp_erp_clear_port_status - clear port status bits
1576  * @port: adapter to change the status
1577  * @mask: status bits to change
1578  *
1579  * Changes in common status bits are propagated to attached LUNs.
1580  */
1581 void zfcp_erp_clear_port_status(struct zfcp_port *port, u32 mask)
1582 {
1583 	struct scsi_device *sdev;
1584 	u32 common_mask = mask & ZFCP_COMMON_FLAGS;
1585 	u32 clear_counter = mask & ZFCP_STATUS_COMMON_ERP_FAILED;
1586 	unsigned long flags;
1587 
1588 	atomic_andnot(mask, &port->status);
1589 
1590 	if (!common_mask)
1591 		return;
1592 
1593 	if (clear_counter)
1594 		atomic_set(&port->erp_counter, 0);
1595 
1596 	spin_lock_irqsave(port->adapter->scsi_host->host_lock, flags);
1597 	__shost_for_each_device(sdev, port->adapter->scsi_host)
1598 		if (sdev_to_zfcp(sdev)->port == port) {
1599 			atomic_andnot(common_mask,
1600 					  &sdev_to_zfcp(sdev)->status);
1601 			if (clear_counter)
1602 				atomic_set(&sdev_to_zfcp(sdev)->erp_counter, 0);
1603 		}
1604 	spin_unlock_irqrestore(port->adapter->scsi_host->host_lock, flags);
1605 }
1606 
1607 /**
1608  * zfcp_erp_set_lun_status - set lun status bits
1609  * @sdev: SCSI device / lun to set the status bits
1610  * @mask: status bits to change
1611  */
1612 void zfcp_erp_set_lun_status(struct scsi_device *sdev, u32 mask)
1613 {
1614 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1615 
1616 	atomic_or(mask, &zfcp_sdev->status);
1617 }
1618 
1619 /**
1620  * zfcp_erp_clear_lun_status - clear lun status bits
1621  * @sdev: SCSi device / lun to clear the status bits
1622  * @mask: status bits to change
1623  */
1624 void zfcp_erp_clear_lun_status(struct scsi_device *sdev, u32 mask)
1625 {
1626 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
1627 
1628 	atomic_andnot(mask, &zfcp_sdev->status);
1629 
1630 	if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
1631 		atomic_set(&zfcp_sdev->erp_counter, 0);
1632 }
1633 
1634