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
184 spin_lock_irqsave(shost->host_lock, flags);
185 if (scsi_host_set_state(shost, SHOST_DEL))
186 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
187 spin_unlock_irqrestore(shost->host_lock, flags);
188
189 transport_unregister_device(&shost->shost_gendev);
190 device_unregister(&shost->shost_dev);
191 device_del(&shost->shost_gendev);
192 }
193 EXPORT_SYMBOL(scsi_remove_host);
194
195 /**
196 * scsi_add_host_with_dma - add a scsi host with dma device
197 * @shost: scsi host pointer to add
198 * @dev: a struct device of type scsi class
199 * @dma_dev: dma device for the host
200 *
201 * Note: You rarely need to worry about this unless you're in a
202 * virtualised host environments, so use the simpler scsi_add_host()
203 * function instead.
204 *
205 * Return value:
206 * 0 on success / != 0 for error
207 **/
scsi_add_host_with_dma(struct Scsi_Host * shost,struct device * dev,struct device * dma_dev)208 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
209 struct device *dma_dev)
210 {
211 struct scsi_host_template *sht = shost->hostt;
212 int error = -EINVAL;
213
214 shost_printk(KERN_INFO, shost, "%s\n",
215 sht->info ? sht->info(shost) : sht->name);
216
217 if (!shost->can_queue) {
218 shost_printk(KERN_ERR, shost,
219 "can_queue = 0 no longer supported\n");
220 goto fail;
221 }
222
223 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
224 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
225 shost->can_queue);
226
227 error = scsi_init_sense_cache(shost);
228 if (error)
229 goto fail;
230
231 error = scsi_mq_setup_tags(shost);
232 if (error)
233 goto fail;
234
235 if (!shost->shost_gendev.parent)
236 shost->shost_gendev.parent = dev ? dev : &platform_bus;
237 if (!dma_dev)
238 dma_dev = shost->shost_gendev.parent;
239
240 shost->dma_dev = dma_dev;
241
242 /*
243 * Increase usage count temporarily here so that calling
244 * scsi_autopm_put_host() will trigger runtime idle if there is
245 * nothing else preventing suspending the device.
246 */
247 pm_runtime_get_noresume(&shost->shost_gendev);
248 pm_runtime_set_active(&shost->shost_gendev);
249 pm_runtime_enable(&shost->shost_gendev);
250 device_enable_async_suspend(&shost->shost_gendev);
251
252 error = device_add(&shost->shost_gendev);
253 if (error)
254 goto out_disable_runtime_pm;
255
256 scsi_host_set_state(shost, SHOST_RUNNING);
257 get_device(shost->shost_gendev.parent);
258
259 device_enable_async_suspend(&shost->shost_dev);
260
261 get_device(&shost->shost_gendev);
262 error = device_add(&shost->shost_dev);
263 if (error)
264 goto out_del_gendev;
265
266 if (shost->transportt->host_size) {
267 shost->shost_data = kzalloc(shost->transportt->host_size,
268 GFP_KERNEL);
269 if (shost->shost_data == NULL) {
270 error = -ENOMEM;
271 goto out_del_dev;
272 }
273 }
274
275 if (shost->transportt->create_work_queue) {
276 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
277 "scsi_wq_%d", shost->host_no);
278 shost->work_q = alloc_workqueue("%s",
279 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
280 1, shost->work_q_name);
281
282 if (!shost->work_q) {
283 error = -EINVAL;
284 goto out_del_dev;
285 }
286 }
287
288 error = scsi_sysfs_add_host(shost);
289 if (error)
290 goto out_del_dev;
291
292 scsi_proc_host_add(shost);
293 scsi_autopm_put_host(shost);
294 return error;
295
296 /*
297 * Any host allocation in this function will be freed in
298 * scsi_host_dev_release().
299 */
300 out_del_dev:
301 device_del(&shost->shost_dev);
302 out_del_gendev:
303 /*
304 * Host state is SHOST_RUNNING so we have to explicitly release
305 * ->shost_dev.
306 */
307 put_device(&shost->shost_dev);
308 device_del(&shost->shost_gendev);
309 out_disable_runtime_pm:
310 device_disable_async_suspend(&shost->shost_gendev);
311 pm_runtime_disable(&shost->shost_gendev);
312 pm_runtime_set_suspended(&shost->shost_gendev);
313 pm_runtime_put_noidle(&shost->shost_gendev);
314 fail:
315 return error;
316 }
317 EXPORT_SYMBOL(scsi_add_host_with_dma);
318
scsi_host_dev_release(struct device * dev)319 static void scsi_host_dev_release(struct device *dev)
320 {
321 struct Scsi_Host *shost = dev_to_shost(dev);
322 struct device *parent = dev->parent;
323
324 scsi_proc_hostdir_rm(shost->hostt);
325
326 /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */
327 rcu_barrier();
328
329 if (shost->tmf_work_q)
330 destroy_workqueue(shost->tmf_work_q);
331 if (shost->ehandler)
332 kthread_stop(shost->ehandler);
333 if (shost->work_q)
334 destroy_workqueue(shost->work_q);
335
336 if (shost->shost_state == SHOST_CREATED) {
337 /*
338 * Free the shost_dev device name here if scsi_host_alloc()
339 * and scsi_host_put() have been called but neither
340 * scsi_host_add() nor scsi_host_remove() has been called.
341 * This avoids that the memory allocated for the shost_dev
342 * name is leaked.
343 */
344 kfree(dev_name(&shost->shost_dev));
345 }
346
347 if (shost->tag_set.tags)
348 scsi_mq_destroy_tags(shost);
349
350 kfree(shost->shost_data);
351
352 ida_simple_remove(&host_index_ida, shost->host_no);
353
354 if (shost->shost_state != SHOST_CREATED)
355 put_device(parent);
356 kfree(shost);
357 }
358
359 static struct device_type scsi_host_type = {
360 .name = "scsi_host",
361 .release = scsi_host_dev_release,
362 };
363
364 /**
365 * scsi_host_alloc - register a scsi host adapter instance.
366 * @sht: pointer to scsi host template
367 * @privsize: extra bytes to allocate for driver
368 *
369 * Note:
370 * Allocate a new Scsi_Host and perform basic initialization.
371 * The host is not published to the scsi midlayer until scsi_add_host
372 * is called.
373 *
374 * Return value:
375 * Pointer to a new Scsi_Host
376 **/
scsi_host_alloc(struct scsi_host_template * sht,int privsize)377 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
378 {
379 struct Scsi_Host *shost;
380 gfp_t gfp_mask = GFP_KERNEL;
381 int index;
382
383 if (sht->unchecked_isa_dma && privsize)
384 gfp_mask |= __GFP_DMA;
385
386 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
387 if (!shost)
388 return NULL;
389
390 shost->host_lock = &shost->default_lock;
391 spin_lock_init(shost->host_lock);
392 shost->shost_state = SHOST_CREATED;
393 INIT_LIST_HEAD(&shost->__devices);
394 INIT_LIST_HEAD(&shost->__targets);
395 INIT_LIST_HEAD(&shost->eh_cmd_q);
396 INIT_LIST_HEAD(&shost->starved_list);
397 init_waitqueue_head(&shost->host_wait);
398 mutex_init(&shost->scan_mutex);
399
400 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
401 if (index < 0) {
402 kfree(shost);
403 return NULL;
404 }
405 shost->host_no = index;
406
407 shost->dma_channel = 0xff;
408
409 /* These three are default values which can be overridden */
410 shost->max_channel = 0;
411 shost->max_id = 8;
412 shost->max_lun = 8;
413
414 /* Give each shost a default transportt */
415 shost->transportt = &blank_transport_template;
416
417 /*
418 * All drivers right now should be able to handle 12 byte
419 * commands. Every so often there are requests for 16 byte
420 * commands, but individual low-level drivers need to certify that
421 * they actually do something sensible with such commands.
422 */
423 shost->max_cmd_len = 12;
424 shost->hostt = sht;
425 shost->this_id = sht->this_id;
426 shost->can_queue = sht->can_queue;
427 shost->sg_tablesize = sht->sg_tablesize;
428 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
429 shost->cmd_per_lun = sht->cmd_per_lun;
430 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
431 shost->no_write_same = sht->no_write_same;
432 shost->host_tagset = sht->host_tagset;
433
434 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
435 shost->eh_deadline = -1;
436 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
437 shost_printk(KERN_WARNING, shost,
438 "eh_deadline %u too large, setting to %u\n",
439 shost_eh_deadline, INT_MAX / HZ);
440 shost->eh_deadline = INT_MAX;
441 } else
442 shost->eh_deadline = shost_eh_deadline * HZ;
443
444 if (sht->supported_mode == MODE_UNKNOWN)
445 /* means we didn't set it ... default to INITIATOR */
446 shost->active_mode = MODE_INITIATOR;
447 else
448 shost->active_mode = sht->supported_mode;
449
450 if (sht->max_host_blocked)
451 shost->max_host_blocked = sht->max_host_blocked;
452 else
453 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
454
455 /*
456 * If the driver imposes no hard sector transfer limit, start at
457 * machine infinity initially.
458 */
459 if (sht->max_sectors)
460 shost->max_sectors = sht->max_sectors;
461 else
462 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
463
464 if (sht->max_segment_size)
465 shost->max_segment_size = sht->max_segment_size;
466 else
467 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
468
469 /*
470 * assume a 4GB boundary, if not set
471 */
472 if (sht->dma_boundary)
473 shost->dma_boundary = sht->dma_boundary;
474 else
475 shost->dma_boundary = 0xffffffff;
476
477 if (sht->virt_boundary_mask)
478 shost->virt_boundary_mask = sht->virt_boundary_mask;
479
480 device_initialize(&shost->shost_gendev);
481 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
482 shost->shost_gendev.bus = &scsi_bus_type;
483 shost->shost_gendev.type = &scsi_host_type;
484
485 device_initialize(&shost->shost_dev);
486 shost->shost_dev.parent = &shost->shost_gendev;
487 shost->shost_dev.class = &shost_class;
488 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
489 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
490
491 shost->ehandler = kthread_run(scsi_error_handler, shost,
492 "scsi_eh_%d", shost->host_no);
493 if (IS_ERR(shost->ehandler)) {
494 shost_printk(KERN_WARNING, shost,
495 "error handler thread failed to spawn, error = %ld\n",
496 PTR_ERR(shost->ehandler));
497 shost->ehandler = NULL;
498 goto fail;
499 }
500
501 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
502 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
503 1, shost->host_no);
504 if (!shost->tmf_work_q) {
505 shost_printk(KERN_WARNING, shost,
506 "failed to create tmf workq\n");
507 goto fail;
508 }
509 scsi_proc_hostdir_add(shost->hostt);
510 return shost;
511 fail:
512 /*
513 * Host state is still SHOST_CREATED and that is enough to release
514 * ->shost_gendev. scsi_host_dev_release() will free
515 * dev_name(&shost->shost_dev).
516 */
517 put_device(&shost->shost_gendev);
518
519 return NULL;
520 }
521 EXPORT_SYMBOL(scsi_host_alloc);
522
__scsi_host_match(struct device * dev,const void * data)523 static int __scsi_host_match(struct device *dev, const void *data)
524 {
525 struct Scsi_Host *p;
526 const unsigned short *hostnum = data;
527
528 p = class_to_shost(dev);
529 return p->host_no == *hostnum;
530 }
531
532 /**
533 * scsi_host_lookup - get a reference to a Scsi_Host by host no
534 * @hostnum: host number to locate
535 *
536 * Return value:
537 * A pointer to located Scsi_Host or NULL.
538 *
539 * The caller must do a scsi_host_put() to drop the reference
540 * that scsi_host_get() took. The put_device() below dropped
541 * the reference from class_find_device().
542 **/
scsi_host_lookup(unsigned short hostnum)543 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
544 {
545 struct device *cdev;
546 struct Scsi_Host *shost = NULL;
547
548 cdev = class_find_device(&shost_class, NULL, &hostnum,
549 __scsi_host_match);
550 if (cdev) {
551 shost = scsi_host_get(class_to_shost(cdev));
552 put_device(cdev);
553 }
554 return shost;
555 }
556 EXPORT_SYMBOL(scsi_host_lookup);
557
558 /**
559 * scsi_host_get - inc a Scsi_Host ref count
560 * @shost: Pointer to Scsi_Host to inc.
561 **/
scsi_host_get(struct Scsi_Host * shost)562 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
563 {
564 if ((shost->shost_state == SHOST_DEL) ||
565 !get_device(&shost->shost_gendev))
566 return NULL;
567 return shost;
568 }
569 EXPORT_SYMBOL(scsi_host_get);
570
scsi_host_check_in_flight(struct request * rq,void * data,bool reserved)571 static bool scsi_host_check_in_flight(struct request *rq, void *data,
572 bool reserved)
573 {
574 int *count = data;
575 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
576
577 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
578 (*count)++;
579
580 return true;
581 }
582
583 /**
584 * scsi_host_busy - Return the host busy counter
585 * @shost: Pointer to Scsi_Host to inc.
586 **/
scsi_host_busy(struct Scsi_Host * shost)587 int scsi_host_busy(struct Scsi_Host *shost)
588 {
589 int cnt = 0;
590
591 blk_mq_tagset_busy_iter(&shost->tag_set,
592 scsi_host_check_in_flight, &cnt);
593 return cnt;
594 }
595 EXPORT_SYMBOL(scsi_host_busy);
596
597 /**
598 * scsi_host_put - dec a Scsi_Host ref count
599 * @shost: Pointer to Scsi_Host to dec.
600 **/
scsi_host_put(struct Scsi_Host * shost)601 void scsi_host_put(struct Scsi_Host *shost)
602 {
603 put_device(&shost->shost_gendev);
604 }
605 EXPORT_SYMBOL(scsi_host_put);
606
scsi_init_hosts(void)607 int scsi_init_hosts(void)
608 {
609 return class_register(&shost_class);
610 }
611
scsi_exit_hosts(void)612 void scsi_exit_hosts(void)
613 {
614 class_unregister(&shost_class);
615 ida_destroy(&host_index_ida);
616 }
617
scsi_is_host_device(const struct device * dev)618 int scsi_is_host_device(const struct device *dev)
619 {
620 return dev->type == &scsi_host_type;
621 }
622 EXPORT_SYMBOL(scsi_is_host_device);
623
624 /**
625 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
626 * @shost: Pointer to Scsi_Host.
627 * @work: Work to queue for execution.
628 *
629 * Return value:
630 * 1 - work queued for execution
631 * 0 - work is already queued
632 * -EINVAL - work queue doesn't exist
633 **/
scsi_queue_work(struct Scsi_Host * shost,struct work_struct * work)634 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
635 {
636 if (unlikely(!shost->work_q)) {
637 shost_printk(KERN_ERR, shost,
638 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
639 "when no workqueue created.\n", shost->hostt->name);
640 dump_stack();
641
642 return -EINVAL;
643 }
644
645 return queue_work(shost->work_q, work);
646 }
647 EXPORT_SYMBOL_GPL(scsi_queue_work);
648
649 /**
650 * scsi_flush_work - Flush a Scsi_Host's workqueue.
651 * @shost: Pointer to Scsi_Host.
652 **/
scsi_flush_work(struct Scsi_Host * shost)653 void scsi_flush_work(struct Scsi_Host *shost)
654 {
655 if (!shost->work_q) {
656 shost_printk(KERN_ERR, shost,
657 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
658 "when no workqueue created.\n", shost->hostt->name);
659 dump_stack();
660 return;
661 }
662
663 flush_workqueue(shost->work_q);
664 }
665 EXPORT_SYMBOL_GPL(scsi_flush_work);
666
complete_all_cmds_iter(struct request * rq,void * data,bool rsvd)667 static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
668 {
669 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
670 int status = *(int *)data;
671
672 scsi_dma_unmap(scmd);
673 scmd->result = status << 16;
674 scmd->scsi_done(scmd);
675 return true;
676 }
677
678 /**
679 * scsi_host_complete_all_commands - Terminate all running commands
680 * @shost: Scsi Host on which commands should be terminated
681 * @status: Status to be set for the terminated commands
682 *
683 * There is no protection against modification of the number
684 * of outstanding commands. It is the responsibility of the
685 * caller to ensure that concurrent I/O submission and/or
686 * completion is stopped when calling this function.
687 */
scsi_host_complete_all_commands(struct Scsi_Host * shost,int status)688 void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
689 {
690 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
691 &status);
692 }
693 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
694
695 struct scsi_host_busy_iter_data {
696 bool (*fn)(struct scsi_cmnd *, void *, bool);
697 void *priv;
698 };
699
__scsi_host_busy_iter_fn(struct request * req,void * priv,bool reserved)700 static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
701 bool reserved)
702 {
703 struct scsi_host_busy_iter_data *iter_data = priv;
704 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
705
706 return iter_data->fn(sc, iter_data->priv, reserved);
707 }
708
709 /**
710 * scsi_host_busy_iter - Iterate over all busy commands
711 * @shost: Pointer to Scsi_Host.
712 * @fn: Function to call on each busy command
713 * @priv: Data pointer passed to @fn
714 *
715 * If locking against concurrent command completions is required
716 * ithas to be provided by the caller
717 **/
scsi_host_busy_iter(struct Scsi_Host * shost,bool (* fn)(struct scsi_cmnd *,void *,bool),void * priv)718 void scsi_host_busy_iter(struct Scsi_Host *shost,
719 bool (*fn)(struct scsi_cmnd *, void *, bool),
720 void *priv)
721 {
722 struct scsi_host_busy_iter_data iter_data = {
723 .fn = fn,
724 .priv = priv,
725 };
726
727 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
728 &iter_data);
729 }
730 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
731