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 gfp_t gfp_mask = GFP_KERNEL;
380 int index;
381
382 if (sht->unchecked_isa_dma && privsize)
383 gfp_mask |= __GFP_DMA;
384
385 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
386 if (!shost)
387 return NULL;
388
389 shost->host_lock = &shost->default_lock;
390 spin_lock_init(shost->host_lock);
391 shost->shost_state = SHOST_CREATED;
392 INIT_LIST_HEAD(&shost->__devices);
393 INIT_LIST_HEAD(&shost->__targets);
394 INIT_LIST_HEAD(&shost->eh_cmd_q);
395 INIT_LIST_HEAD(&shost->starved_list);
396 init_waitqueue_head(&shost->host_wait);
397 mutex_init(&shost->scan_mutex);
398
399 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
400 if (index < 0) {
401 kfree(shost);
402 return NULL;
403 }
404 shost->host_no = index;
405
406 shost->dma_channel = 0xff;
407
408 /* These three are default values which can be overridden */
409 shost->max_channel = 0;
410 shost->max_id = 8;
411 shost->max_lun = 8;
412
413 /* Give each shost a default transportt */
414 shost->transportt = &blank_transport_template;
415
416 /*
417 * All drivers right now should be able to handle 12 byte
418 * commands. Every so often there are requests for 16 byte
419 * commands, but individual low-level drivers need to certify that
420 * they actually do something sensible with such commands.
421 */
422 shost->max_cmd_len = 12;
423 shost->hostt = sht;
424 shost->this_id = sht->this_id;
425 shost->can_queue = sht->can_queue;
426 shost->sg_tablesize = sht->sg_tablesize;
427 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
428 shost->cmd_per_lun = sht->cmd_per_lun;
429 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
430 shost->no_write_same = sht->no_write_same;
431 shost->host_tagset = sht->host_tagset;
432
433 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
434 shost->eh_deadline = -1;
435 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
436 shost_printk(KERN_WARNING, shost,
437 "eh_deadline %u too large, setting to %u\n",
438 shost_eh_deadline, INT_MAX / HZ);
439 shost->eh_deadline = INT_MAX;
440 } else
441 shost->eh_deadline = shost_eh_deadline * HZ;
442
443 if (sht->supported_mode == MODE_UNKNOWN)
444 /* means we didn't set it ... default to INITIATOR */
445 shost->active_mode = MODE_INITIATOR;
446 else
447 shost->active_mode = sht->supported_mode;
448
449 if (sht->max_host_blocked)
450 shost->max_host_blocked = sht->max_host_blocked;
451 else
452 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
453
454 /*
455 * If the driver imposes no hard sector transfer limit, start at
456 * machine infinity initially.
457 */
458 if (sht->max_sectors)
459 shost->max_sectors = sht->max_sectors;
460 else
461 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
462
463 if (sht->max_segment_size)
464 shost->max_segment_size = sht->max_segment_size;
465 else
466 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
467
468 /*
469 * assume a 4GB boundary, if not set
470 */
471 if (sht->dma_boundary)
472 shost->dma_boundary = sht->dma_boundary;
473 else
474 shost->dma_boundary = 0xffffffff;
475
476 if (sht->virt_boundary_mask)
477 shost->virt_boundary_mask = sht->virt_boundary_mask;
478
479 device_initialize(&shost->shost_gendev);
480 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
481 shost->shost_gendev.bus = &scsi_bus_type;
482 shost->shost_gendev.type = &scsi_host_type;
483
484 device_initialize(&shost->shost_dev);
485 shost->shost_dev.parent = &shost->shost_gendev;
486 shost->shost_dev.class = &shost_class;
487 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
488 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
489
490 shost->ehandler = kthread_run(scsi_error_handler, shost,
491 "scsi_eh_%d", shost->host_no);
492 if (IS_ERR(shost->ehandler)) {
493 shost_printk(KERN_WARNING, shost,
494 "error handler thread failed to spawn, error = %ld\n",
495 PTR_ERR(shost->ehandler));
496 shost->ehandler = NULL;
497 goto fail;
498 }
499
500 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
501 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
502 1, shost->host_no);
503 if (!shost->tmf_work_q) {
504 shost_printk(KERN_WARNING, shost,
505 "failed to create tmf workq\n");
506 goto fail;
507 }
508 scsi_proc_hostdir_add(shost->hostt);
509 return shost;
510 fail:
511 /*
512 * Host state is still SHOST_CREATED and that is enough to release
513 * ->shost_gendev. scsi_host_dev_release() will free
514 * dev_name(&shost->shost_dev).
515 */
516 put_device(&shost->shost_gendev);
517
518 return NULL;
519 }
520 EXPORT_SYMBOL(scsi_host_alloc);
521
__scsi_host_match(struct device * dev,const void * data)522 static int __scsi_host_match(struct device *dev, const void *data)
523 {
524 struct Scsi_Host *p;
525 const unsigned short *hostnum = data;
526
527 p = class_to_shost(dev);
528 return p->host_no == *hostnum;
529 }
530
531 /**
532 * scsi_host_lookup - get a reference to a Scsi_Host by host no
533 * @hostnum: host number to locate
534 *
535 * Return value:
536 * A pointer to located Scsi_Host or NULL.
537 *
538 * The caller must do a scsi_host_put() to drop the reference
539 * that scsi_host_get() took. The put_device() below dropped
540 * the reference from class_find_device().
541 **/
scsi_host_lookup(unsigned short hostnum)542 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
543 {
544 struct device *cdev;
545 struct Scsi_Host *shost = NULL;
546
547 cdev = class_find_device(&shost_class, NULL, &hostnum,
548 __scsi_host_match);
549 if (cdev) {
550 shost = scsi_host_get(class_to_shost(cdev));
551 put_device(cdev);
552 }
553 return shost;
554 }
555 EXPORT_SYMBOL(scsi_host_lookup);
556
557 /**
558 * scsi_host_get - inc a Scsi_Host ref count
559 * @shost: Pointer to Scsi_Host to inc.
560 **/
scsi_host_get(struct Scsi_Host * shost)561 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
562 {
563 if ((shost->shost_state == SHOST_DEL) ||
564 !get_device(&shost->shost_gendev))
565 return NULL;
566 return shost;
567 }
568 EXPORT_SYMBOL(scsi_host_get);
569
scsi_host_check_in_flight(struct request * rq,void * data,bool reserved)570 static bool scsi_host_check_in_flight(struct request *rq, void *data,
571 bool reserved)
572 {
573 int *count = data;
574 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
575
576 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
577 (*count)++;
578
579 return true;
580 }
581
582 /**
583 * scsi_host_busy - Return the host busy counter
584 * @shost: Pointer to Scsi_Host to inc.
585 **/
scsi_host_busy(struct Scsi_Host * shost)586 int scsi_host_busy(struct Scsi_Host *shost)
587 {
588 int cnt = 0;
589
590 blk_mq_tagset_busy_iter(&shost->tag_set,
591 scsi_host_check_in_flight, &cnt);
592 return cnt;
593 }
594 EXPORT_SYMBOL(scsi_host_busy);
595
596 /**
597 * scsi_host_put - dec a Scsi_Host ref count
598 * @shost: Pointer to Scsi_Host to dec.
599 **/
scsi_host_put(struct Scsi_Host * shost)600 void scsi_host_put(struct Scsi_Host *shost)
601 {
602 put_device(&shost->shost_gendev);
603 }
604 EXPORT_SYMBOL(scsi_host_put);
605
scsi_init_hosts(void)606 int scsi_init_hosts(void)
607 {
608 return class_register(&shost_class);
609 }
610
scsi_exit_hosts(void)611 void scsi_exit_hosts(void)
612 {
613 class_unregister(&shost_class);
614 ida_destroy(&host_index_ida);
615 }
616
scsi_is_host_device(const struct device * dev)617 int scsi_is_host_device(const struct device *dev)
618 {
619 return dev->type == &scsi_host_type;
620 }
621 EXPORT_SYMBOL(scsi_is_host_device);
622
623 /**
624 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
625 * @shost: Pointer to Scsi_Host.
626 * @work: Work to queue for execution.
627 *
628 * Return value:
629 * 1 - work queued for execution
630 * 0 - work is already queued
631 * -EINVAL - work queue doesn't exist
632 **/
scsi_queue_work(struct Scsi_Host * shost,struct work_struct * work)633 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
634 {
635 if (unlikely(!shost->work_q)) {
636 shost_printk(KERN_ERR, shost,
637 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
638 "when no workqueue created.\n", shost->hostt->name);
639 dump_stack();
640
641 return -EINVAL;
642 }
643
644 return queue_work(shost->work_q, work);
645 }
646 EXPORT_SYMBOL_GPL(scsi_queue_work);
647
648 /**
649 * scsi_flush_work - Flush a Scsi_Host's workqueue.
650 * @shost: Pointer to Scsi_Host.
651 **/
scsi_flush_work(struct Scsi_Host * shost)652 void scsi_flush_work(struct Scsi_Host *shost)
653 {
654 if (!shost->work_q) {
655 shost_printk(KERN_ERR, shost,
656 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
657 "when no workqueue created.\n", shost->hostt->name);
658 dump_stack();
659 return;
660 }
661
662 flush_workqueue(shost->work_q);
663 }
664 EXPORT_SYMBOL_GPL(scsi_flush_work);
665
complete_all_cmds_iter(struct request * rq,void * data,bool rsvd)666 static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
667 {
668 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
669 int status = *(int *)data;
670
671 scsi_dma_unmap(scmd);
672 scmd->result = status << 16;
673 scmd->scsi_done(scmd);
674 return true;
675 }
676
677 /**
678 * scsi_host_complete_all_commands - Terminate all running commands
679 * @shost: Scsi Host on which commands should be terminated
680 * @status: Status to be set for the terminated commands
681 *
682 * There is no protection against modification of the number
683 * of outstanding commands. It is the responsibility of the
684 * caller to ensure that concurrent I/O submission and/or
685 * completion is stopped when calling this function.
686 */
scsi_host_complete_all_commands(struct Scsi_Host * shost,int status)687 void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
688 {
689 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
690 &status);
691 }
692 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
693
694 struct scsi_host_busy_iter_data {
695 bool (*fn)(struct scsi_cmnd *, void *, bool);
696 void *priv;
697 };
698
__scsi_host_busy_iter_fn(struct request * req,void * priv,bool reserved)699 static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
700 bool reserved)
701 {
702 struct scsi_host_busy_iter_data *iter_data = priv;
703 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
704
705 return iter_data->fn(sc, iter_data->priv, reserved);
706 }
707
708 /**
709 * scsi_host_busy_iter - Iterate over all busy commands
710 * @shost: Pointer to Scsi_Host.
711 * @fn: Function to call on each busy command
712 * @priv: Data pointer passed to @fn
713 *
714 * If locking against concurrent command completions is required
715 * ithas to be provided by the caller
716 **/
scsi_host_busy_iter(struct Scsi_Host * shost,bool (* fn)(struct scsi_cmnd *,void *,bool),void * priv)717 void scsi_host_busy_iter(struct Scsi_Host *shost,
718 bool (*fn)(struct scsi_cmnd *, void *, bool),
719 void *priv)
720 {
721 struct scsi_host_busy_iter_data iter_data = {
722 .fn = fn,
723 .priv = priv,
724 };
725
726 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
727 &iter_data);
728 }
729 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
730