1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * hosts.c Copyright (C) 1992 Drew Eckhardt
4 * Copyright (C) 1993, 1994, 1995 Eric Youngdale
5 * Copyright (C) 2002-2003 Christoph Hellwig
6 *
7 * mid to lowlevel SCSI driver interface
8 * Initial versions: Drew Eckhardt
9 * Subsequent revisions: Eric Youngdale
10 *
11 * <drew@colorado.edu>
12 *
13 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
14 * Added QLOGIC QLA1280 SCSI controller kernel host support.
15 * August 4, 1999 Fred Lewis, Intel DuPont
16 *
17 * Updated to reflect the new initialization scheme for the higher
18 * level of scsi drivers (sd/sr/st)
19 * September 17, 2000 Torben Mathiasen <tmm@image.dk>
20 *
21 * Restructured scsi_host lists and associated functions.
22 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
23 */
24
25 #include <linux/module.h>
26 #include <linux/blkdev.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/kthread.h>
30 #include <linux/string.h>
31 #include <linux/mm.h>
32 #include <linux/init.h>
33 #include <linux/completion.h>
34 #include <linux/transport_class.h>
35 #include <linux/platform_device.h>
36 #include <linux/pm_runtime.h>
37 #include <linux/idr.h>
38 #include <scsi/scsi_device.h>
39 #include <scsi/scsi_host.h>
40 #include <scsi/scsi_transport.h>
41 #include <scsi/scsi_cmnd.h>
42
43 #include "scsi_priv.h"
44 #include "scsi_logging.h"
45
46
47 static int shost_eh_deadline = -1;
48
49 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
50 MODULE_PARM_DESC(eh_deadline,
51 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
52
53 static DEFINE_IDA(host_index_ida);
54
55
scsi_host_cls_release(struct device * dev)56 static void scsi_host_cls_release(struct device *dev)
57 {
58 put_device(&class_to_shost(dev)->shost_gendev);
59 }
60
61 static struct class shost_class = {
62 .name = "scsi_host",
63 .dev_release = scsi_host_cls_release,
64 };
65
66 /**
67 * scsi_host_set_state - Take the given host through the host state model.
68 * @shost: scsi host to change the state of.
69 * @state: state to change to.
70 *
71 * Returns zero if unsuccessful or an error if the requested
72 * transition is illegal.
73 **/
scsi_host_set_state(struct Scsi_Host * shost,enum scsi_host_state state)74 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
75 {
76 enum scsi_host_state oldstate = shost->shost_state;
77
78 if (state == oldstate)
79 return 0;
80
81 switch (state) {
82 case SHOST_CREATED:
83 /* There are no legal states that come back to
84 * created. This is the manually initialised start
85 * state */
86 goto illegal;
87
88 case SHOST_RUNNING:
89 switch (oldstate) {
90 case SHOST_CREATED:
91 case SHOST_RECOVERY:
92 break;
93 default:
94 goto illegal;
95 }
96 break;
97
98 case SHOST_RECOVERY:
99 switch (oldstate) {
100 case SHOST_RUNNING:
101 break;
102 default:
103 goto illegal;
104 }
105 break;
106
107 case SHOST_CANCEL:
108 switch (oldstate) {
109 case SHOST_CREATED:
110 case SHOST_RUNNING:
111 case SHOST_CANCEL_RECOVERY:
112 break;
113 default:
114 goto illegal;
115 }
116 break;
117
118 case SHOST_DEL:
119 switch (oldstate) {
120 case SHOST_CANCEL:
121 case SHOST_DEL_RECOVERY:
122 break;
123 default:
124 goto illegal;
125 }
126 break;
127
128 case SHOST_CANCEL_RECOVERY:
129 switch (oldstate) {
130 case SHOST_CANCEL:
131 case SHOST_RECOVERY:
132 break;
133 default:
134 goto illegal;
135 }
136 break;
137
138 case SHOST_DEL_RECOVERY:
139 switch (oldstate) {
140 case SHOST_CANCEL_RECOVERY:
141 break;
142 default:
143 goto illegal;
144 }
145 break;
146 }
147 shost->shost_state = state;
148 return 0;
149
150 illegal:
151 SCSI_LOG_ERROR_RECOVERY(1,
152 shost_printk(KERN_ERR, shost,
153 "Illegal host state transition"
154 "%s->%s\n",
155 scsi_host_state_name(oldstate),
156 scsi_host_state_name(state)));
157 return -EINVAL;
158 }
159
160 /**
161 * scsi_remove_host - remove a scsi host
162 * @shost: a pointer to a scsi host to remove
163 **/
scsi_remove_host(struct Scsi_Host * shost)164 void scsi_remove_host(struct Scsi_Host *shost)
165 {
166 unsigned long flags;
167
168 mutex_lock(&shost->scan_mutex);
169 spin_lock_irqsave(shost->host_lock, flags);
170 if (scsi_host_set_state(shost, SHOST_CANCEL))
171 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
172 spin_unlock_irqrestore(shost->host_lock, flags);
173 mutex_unlock(&shost->scan_mutex);
174 return;
175 }
176 spin_unlock_irqrestore(shost->host_lock, flags);
177
178 scsi_autopm_get_host(shost);
179 flush_workqueue(shost->tmf_work_q);
180 scsi_forget_host(shost);
181 mutex_unlock(&shost->scan_mutex);
182 scsi_proc_host_rm(shost);
183 scsi_proc_hostdir_rm(shost->hostt);
184
185 spin_lock_irqsave(shost->host_lock, flags);
186 if (scsi_host_set_state(shost, SHOST_DEL))
187 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
188 spin_unlock_irqrestore(shost->host_lock, flags);
189
190 transport_unregister_device(&shost->shost_gendev);
191 device_unregister(&shost->shost_dev);
192 device_del(&shost->shost_gendev);
193 }
194 EXPORT_SYMBOL(scsi_remove_host);
195
196 /**
197 * scsi_add_host_with_dma - add a scsi host with dma device
198 * @shost: scsi host pointer to add
199 * @dev: a struct device of type scsi class
200 * @dma_dev: dma device for the host
201 *
202 * Note: You rarely need to worry about this unless you're in a
203 * virtualised host environments, so use the simpler scsi_add_host()
204 * function instead.
205 *
206 * Return value:
207 * 0 on success / != 0 for error
208 **/
scsi_add_host_with_dma(struct Scsi_Host * shost,struct device * dev,struct device * dma_dev)209 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
210 struct device *dma_dev)
211 {
212 struct scsi_host_template *sht = shost->hostt;
213 int error = -EINVAL;
214
215 shost_printk(KERN_INFO, shost, "%s\n",
216 sht->info ? sht->info(shost) : sht->name);
217
218 if (!shost->can_queue) {
219 shost_printk(KERN_ERR, shost,
220 "can_queue = 0 no longer supported\n");
221 goto fail;
222 }
223
224 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
225 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
226 shost->can_queue);
227
228 error = scsi_init_sense_cache(shost);
229 if (error)
230 goto fail;
231
232 error = scsi_mq_setup_tags(shost);
233 if (error)
234 goto fail;
235
236 if (!shost->shost_gendev.parent)
237 shost->shost_gendev.parent = dev ? dev : &platform_bus;
238 if (!dma_dev)
239 dma_dev = shost->shost_gendev.parent;
240
241 shost->dma_dev = dma_dev;
242
243 /*
244 * Increase usage count temporarily here so that calling
245 * scsi_autopm_put_host() will trigger runtime idle if there is
246 * nothing else preventing suspending the device.
247 */
248 pm_runtime_get_noresume(&shost->shost_gendev);
249 pm_runtime_set_active(&shost->shost_gendev);
250 pm_runtime_enable(&shost->shost_gendev);
251 device_enable_async_suspend(&shost->shost_gendev);
252
253 error = device_add(&shost->shost_gendev);
254 if (error)
255 goto out_disable_runtime_pm;
256
257 scsi_host_set_state(shost, SHOST_RUNNING);
258 get_device(shost->shost_gendev.parent);
259
260 device_enable_async_suspend(&shost->shost_dev);
261
262 get_device(&shost->shost_gendev);
263 error = device_add(&shost->shost_dev);
264 if (error)
265 goto out_del_gendev;
266
267 if (shost->transportt->host_size) {
268 shost->shost_data = kzalloc(shost->transportt->host_size,
269 GFP_KERNEL);
270 if (shost->shost_data == NULL) {
271 error = -ENOMEM;
272 goto out_del_dev;
273 }
274 }
275
276 if (shost->transportt->create_work_queue) {
277 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
278 "scsi_wq_%d", shost->host_no);
279 shost->work_q = alloc_workqueue("%s",
280 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
281 1, shost->work_q_name);
282
283 if (!shost->work_q) {
284 error = -EINVAL;
285 goto out_del_dev;
286 }
287 }
288
289 error = scsi_sysfs_add_host(shost);
290 if (error)
291 goto out_del_dev;
292
293 scsi_proc_host_add(shost);
294 scsi_autopm_put_host(shost);
295 return error;
296
297 /*
298 * Any host allocation in this function will be freed in
299 * scsi_host_dev_release().
300 */
301 out_del_dev:
302 device_del(&shost->shost_dev);
303 out_del_gendev:
304 /*
305 * Host state is SHOST_RUNNING so we have to explicitly release
306 * ->shost_dev.
307 */
308 put_device(&shost->shost_dev);
309 device_del(&shost->shost_gendev);
310 out_disable_runtime_pm:
311 device_disable_async_suspend(&shost->shost_gendev);
312 pm_runtime_disable(&shost->shost_gendev);
313 pm_runtime_set_suspended(&shost->shost_gendev);
314 pm_runtime_put_noidle(&shost->shost_gendev);
315 fail:
316 return error;
317 }
318 EXPORT_SYMBOL(scsi_add_host_with_dma);
319
scsi_host_dev_release(struct device * dev)320 static void scsi_host_dev_release(struct device *dev)
321 {
322 struct Scsi_Host *shost = dev_to_shost(dev);
323 struct device *parent = dev->parent;
324
325 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
326 rcu_barrier();
327
328 if (shost->tmf_work_q)
329 destroy_workqueue(shost->tmf_work_q);
330 if (shost->ehandler)
331 kthread_stop(shost->ehandler);
332 if (shost->work_q)
333 destroy_workqueue(shost->work_q);
334
335 if (shost->shost_state == SHOST_CREATED) {
336 /*
337 * Free the shost_dev device name here if scsi_host_alloc()
338 * and scsi_host_put() have been called but neither
339 * scsi_host_add() nor scsi_host_remove() has been called.
340 * This avoids that the memory allocated for the shost_dev
341 * name is leaked.
342 */
343 kfree(dev_name(&shost->shost_dev));
344 }
345
346 if (shost->tag_set.tags)
347 scsi_mq_destroy_tags(shost);
348
349 kfree(shost->shost_data);
350
351 ida_simple_remove(&host_index_ida, shost->host_no);
352
353 if (shost->shost_state != SHOST_CREATED)
354 put_device(parent);
355 kfree(shost);
356 }
357
358 static struct device_type scsi_host_type = {
359 .name = "scsi_host",
360 .release = scsi_host_dev_release,
361 };
362
363 /**
364 * scsi_host_alloc - register a scsi host adapter instance.
365 * @sht: pointer to scsi host template
366 * @privsize: extra bytes to allocate for driver
367 *
368 * Note:
369 * Allocate a new Scsi_Host and perform basic initialization.
370 * The host is not published to the scsi midlayer until scsi_add_host
371 * is called.
372 *
373 * Return value:
374 * Pointer to a new Scsi_Host
375 **/
scsi_host_alloc(struct scsi_host_template * sht,int privsize)376 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
377 {
378 struct Scsi_Host *shost;
379 int index;
380
381 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
382 if (!shost)
383 return NULL;
384
385 shost->host_lock = &shost->default_lock;
386 spin_lock_init(shost->host_lock);
387 shost->shost_state = SHOST_CREATED;
388 INIT_LIST_HEAD(&shost->__devices);
389 INIT_LIST_HEAD(&shost->__targets);
390 INIT_LIST_HEAD(&shost->eh_abort_list);
391 INIT_LIST_HEAD(&shost->eh_cmd_q);
392 INIT_LIST_HEAD(&shost->starved_list);
393 init_waitqueue_head(&shost->host_wait);
394 mutex_init(&shost->scan_mutex);
395
396 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
397 if (index < 0) {
398 kfree(shost);
399 return NULL;
400 }
401 shost->host_no = index;
402
403 shost->dma_channel = 0xff;
404
405 /* These three are default values which can be overridden */
406 shost->max_channel = 0;
407 shost->max_id = 8;
408 shost->max_lun = 8;
409
410 /* Give each shost a default transportt */
411 shost->transportt = &blank_transport_template;
412
413 /*
414 * All drivers right now should be able to handle 12 byte
415 * commands. Every so often there are requests for 16 byte
416 * commands, but individual low-level drivers need to certify that
417 * they actually do something sensible with such commands.
418 */
419 shost->max_cmd_len = 12;
420 shost->hostt = sht;
421 shost->this_id = sht->this_id;
422 shost->can_queue = sht->can_queue;
423 shost->sg_tablesize = sht->sg_tablesize;
424 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
425 shost->cmd_per_lun = sht->cmd_per_lun;
426 shost->no_write_same = sht->no_write_same;
427 shost->host_tagset = sht->host_tagset;
428
429 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
430 shost->eh_deadline = -1;
431 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
432 shost_printk(KERN_WARNING, shost,
433 "eh_deadline %u too large, setting to %u\n",
434 shost_eh_deadline, INT_MAX / HZ);
435 shost->eh_deadline = INT_MAX;
436 } else
437 shost->eh_deadline = shost_eh_deadline * HZ;
438
439 if (sht->supported_mode == MODE_UNKNOWN)
440 /* means we didn't set it ... default to INITIATOR */
441 shost->active_mode = MODE_INITIATOR;
442 else
443 shost->active_mode = sht->supported_mode;
444
445 if (sht->max_host_blocked)
446 shost->max_host_blocked = sht->max_host_blocked;
447 else
448 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
449
450 /*
451 * If the driver imposes no hard sector transfer limit, start at
452 * machine infinity initially.
453 */
454 if (sht->max_sectors)
455 shost->max_sectors = sht->max_sectors;
456 else
457 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
458
459 if (sht->max_segment_size)
460 shost->max_segment_size = sht->max_segment_size;
461 else
462 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
463
464 /*
465 * assume a 4GB boundary, if not set
466 */
467 if (sht->dma_boundary)
468 shost->dma_boundary = sht->dma_boundary;
469 else
470 shost->dma_boundary = 0xffffffff;
471
472 if (sht->virt_boundary_mask)
473 shost->virt_boundary_mask = sht->virt_boundary_mask;
474
475 device_initialize(&shost->shost_gendev);
476 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
477 shost->shost_gendev.bus = &scsi_bus_type;
478 shost->shost_gendev.type = &scsi_host_type;
479
480 device_initialize(&shost->shost_dev);
481 shost->shost_dev.parent = &shost->shost_gendev;
482 shost->shost_dev.class = &shost_class;
483 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
484 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
485
486 shost->ehandler = kthread_run(scsi_error_handler, shost,
487 "scsi_eh_%d", shost->host_no);
488 if (IS_ERR(shost->ehandler)) {
489 shost_printk(KERN_WARNING, shost,
490 "error handler thread failed to spawn, error = %ld\n",
491 PTR_ERR(shost->ehandler));
492 shost->ehandler = NULL;
493 goto fail;
494 }
495
496 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
497 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
498 1, shost->host_no);
499 if (!shost->tmf_work_q) {
500 shost_printk(KERN_WARNING, shost,
501 "failed to create tmf workq\n");
502 goto fail;
503 }
504 scsi_proc_hostdir_add(shost->hostt);
505 return shost;
506 fail:
507 /*
508 * Host state is still SHOST_CREATED and that is enough to release
509 * ->shost_gendev. scsi_host_dev_release() will free
510 * dev_name(&shost->shost_dev).
511 */
512 put_device(&shost->shost_gendev);
513
514 return NULL;
515 }
516 EXPORT_SYMBOL(scsi_host_alloc);
517
__scsi_host_match(struct device * dev,const void * data)518 static int __scsi_host_match(struct device *dev, const void *data)
519 {
520 struct Scsi_Host *p;
521 const unsigned short *hostnum = data;
522
523 p = class_to_shost(dev);
524 return p->host_no == *hostnum;
525 }
526
527 /**
528 * scsi_host_lookup - get a reference to a Scsi_Host by host no
529 * @hostnum: host number to locate
530 *
531 * Return value:
532 * A pointer to located Scsi_Host or NULL.
533 *
534 * The caller must do a scsi_host_put() to drop the reference
535 * that scsi_host_get() took. The put_device() below dropped
536 * the reference from class_find_device().
537 **/
scsi_host_lookup(unsigned short hostnum)538 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
539 {
540 struct device *cdev;
541 struct Scsi_Host *shost = NULL;
542
543 cdev = class_find_device(&shost_class, NULL, &hostnum,
544 __scsi_host_match);
545 if (cdev) {
546 shost = scsi_host_get(class_to_shost(cdev));
547 put_device(cdev);
548 }
549 return shost;
550 }
551 EXPORT_SYMBOL(scsi_host_lookup);
552
553 /**
554 * scsi_host_get - inc a Scsi_Host ref count
555 * @shost: Pointer to Scsi_Host to inc.
556 **/
scsi_host_get(struct Scsi_Host * shost)557 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
558 {
559 if ((shost->shost_state == SHOST_DEL) ||
560 !get_device(&shost->shost_gendev))
561 return NULL;
562 return shost;
563 }
564 EXPORT_SYMBOL(scsi_host_get);
565
scsi_host_check_in_flight(struct request * rq,void * data,bool reserved)566 static bool scsi_host_check_in_flight(struct request *rq, void *data,
567 bool reserved)
568 {
569 int *count = data;
570 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
571
572 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
573 (*count)++;
574
575 return true;
576 }
577
578 /**
579 * scsi_host_busy - Return the host busy counter
580 * @shost: Pointer to Scsi_Host to inc.
581 **/
scsi_host_busy(struct Scsi_Host * shost)582 int scsi_host_busy(struct Scsi_Host *shost)
583 {
584 int cnt = 0;
585
586 blk_mq_tagset_busy_iter(&shost->tag_set,
587 scsi_host_check_in_flight, &cnt);
588 return cnt;
589 }
590 EXPORT_SYMBOL(scsi_host_busy);
591
592 /**
593 * scsi_host_put - dec a Scsi_Host ref count
594 * @shost: Pointer to Scsi_Host to dec.
595 **/
scsi_host_put(struct Scsi_Host * shost)596 void scsi_host_put(struct Scsi_Host *shost)
597 {
598 put_device(&shost->shost_gendev);
599 }
600 EXPORT_SYMBOL(scsi_host_put);
601
scsi_init_hosts(void)602 int scsi_init_hosts(void)
603 {
604 return class_register(&shost_class);
605 }
606
scsi_exit_hosts(void)607 void scsi_exit_hosts(void)
608 {
609 class_unregister(&shost_class);
610 ida_destroy(&host_index_ida);
611 }
612
scsi_is_host_device(const struct device * dev)613 int scsi_is_host_device(const struct device *dev)
614 {
615 return dev->type == &scsi_host_type;
616 }
617 EXPORT_SYMBOL(scsi_is_host_device);
618
619 /**
620 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
621 * @shost: Pointer to Scsi_Host.
622 * @work: Work to queue for execution.
623 *
624 * Return value:
625 * 1 - work queued for execution
626 * 0 - work is already queued
627 * -EINVAL - work queue doesn't exist
628 **/
scsi_queue_work(struct Scsi_Host * shost,struct work_struct * work)629 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
630 {
631 if (unlikely(!shost->work_q)) {
632 shost_printk(KERN_ERR, shost,
633 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
634 "when no workqueue created.\n", shost->hostt->name);
635 dump_stack();
636
637 return -EINVAL;
638 }
639
640 return queue_work(shost->work_q, work);
641 }
642 EXPORT_SYMBOL_GPL(scsi_queue_work);
643
644 /**
645 * scsi_flush_work - Flush a Scsi_Host's workqueue.
646 * @shost: Pointer to Scsi_Host.
647 **/
scsi_flush_work(struct Scsi_Host * shost)648 void scsi_flush_work(struct Scsi_Host *shost)
649 {
650 if (!shost->work_q) {
651 shost_printk(KERN_ERR, shost,
652 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
653 "when no workqueue created.\n", shost->hostt->name);
654 dump_stack();
655 return;
656 }
657
658 flush_workqueue(shost->work_q);
659 }
660 EXPORT_SYMBOL_GPL(scsi_flush_work);
661
complete_all_cmds_iter(struct request * rq,void * data,bool rsvd)662 static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
663 {
664 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
665 enum scsi_host_status status = *(enum scsi_host_status *)data;
666
667 scsi_dma_unmap(scmd);
668 scmd->result = 0;
669 set_host_byte(scmd, status);
670 scmd->scsi_done(scmd);
671 return true;
672 }
673
674 /**
675 * scsi_host_complete_all_commands - Terminate all running commands
676 * @shost: Scsi Host on which commands should be terminated
677 * @status: Status to be set for the terminated commands
678 *
679 * There is no protection against modification of the number
680 * of outstanding commands. It is the responsibility of the
681 * caller to ensure that concurrent I/O submission and/or
682 * completion is stopped when calling this function.
683 */
scsi_host_complete_all_commands(struct Scsi_Host * shost,enum scsi_host_status status)684 void scsi_host_complete_all_commands(struct Scsi_Host *shost,
685 enum scsi_host_status status)
686 {
687 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
688 &status);
689 }
690 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
691
692 struct scsi_host_busy_iter_data {
693 bool (*fn)(struct scsi_cmnd *, void *, bool);
694 void *priv;
695 };
696
__scsi_host_busy_iter_fn(struct request * req,void * priv,bool reserved)697 static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
698 bool reserved)
699 {
700 struct scsi_host_busy_iter_data *iter_data = priv;
701 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
702
703 return iter_data->fn(sc, iter_data->priv, reserved);
704 }
705
706 /**
707 * scsi_host_busy_iter - Iterate over all busy commands
708 * @shost: Pointer to Scsi_Host.
709 * @fn: Function to call on each busy command
710 * @priv: Data pointer passed to @fn
711 *
712 * If locking against concurrent command completions is required
713 * ithas to be provided by the caller
714 **/
scsi_host_busy_iter(struct Scsi_Host * shost,bool (* fn)(struct scsi_cmnd *,void *,bool),void * priv)715 void scsi_host_busy_iter(struct Scsi_Host *shost,
716 bool (*fn)(struct scsi_cmnd *, void *, bool),
717 void *priv)
718 {
719 struct scsi_host_busy_iter_data iter_data = {
720 .fn = fn,
721 .priv = priv,
722 };
723
724 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
725 &iter_data);
726 }
727 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
728