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 .dev_groups = scsi_shost_groups,
65 };
66
67 /**
68 * scsi_host_set_state - Take the given host through the host state model.
69 * @shost: scsi host to change the state of.
70 * @state: state to change to.
71 *
72 * Returns zero if unsuccessful or an error if the requested
73 * transition is illegal.
74 **/
scsi_host_set_state(struct Scsi_Host * shost,enum scsi_host_state state)75 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
76 {
77 enum scsi_host_state oldstate = shost->shost_state;
78
79 if (state == oldstate)
80 return 0;
81
82 switch (state) {
83 case SHOST_CREATED:
84 /* There are no legal states that come back to
85 * created. This is the manually initialised start
86 * state */
87 goto illegal;
88
89 case SHOST_RUNNING:
90 switch (oldstate) {
91 case SHOST_CREATED:
92 case SHOST_RECOVERY:
93 break;
94 default:
95 goto illegal;
96 }
97 break;
98
99 case SHOST_RECOVERY:
100 switch (oldstate) {
101 case SHOST_RUNNING:
102 break;
103 default:
104 goto illegal;
105 }
106 break;
107
108 case SHOST_CANCEL:
109 switch (oldstate) {
110 case SHOST_CREATED:
111 case SHOST_RUNNING:
112 case SHOST_CANCEL_RECOVERY:
113 break;
114 default:
115 goto illegal;
116 }
117 break;
118
119 case SHOST_DEL:
120 switch (oldstate) {
121 case SHOST_CANCEL:
122 case SHOST_DEL_RECOVERY:
123 break;
124 default:
125 goto illegal;
126 }
127 break;
128
129 case SHOST_CANCEL_RECOVERY:
130 switch (oldstate) {
131 case SHOST_CANCEL:
132 case SHOST_RECOVERY:
133 break;
134 default:
135 goto illegal;
136 }
137 break;
138
139 case SHOST_DEL_RECOVERY:
140 switch (oldstate) {
141 case SHOST_CANCEL_RECOVERY:
142 break;
143 default:
144 goto illegal;
145 }
146 break;
147 }
148 shost->shost_state = state;
149 return 0;
150
151 illegal:
152 SCSI_LOG_ERROR_RECOVERY(1,
153 shost_printk(KERN_ERR, shost,
154 "Illegal host state transition"
155 "%s->%s\n",
156 scsi_host_state_name(oldstate),
157 scsi_host_state_name(state)));
158 return -EINVAL;
159 }
160
161 /**
162 * scsi_remove_host - remove a scsi host
163 * @shost: a pointer to a scsi host to remove
164 **/
scsi_remove_host(struct Scsi_Host * shost)165 void scsi_remove_host(struct Scsi_Host *shost)
166 {
167 unsigned long flags;
168
169 mutex_lock(&shost->scan_mutex);
170 spin_lock_irqsave(shost->host_lock, flags);
171 if (scsi_host_set_state(shost, SHOST_CANCEL))
172 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
173 spin_unlock_irqrestore(shost->host_lock, flags);
174 mutex_unlock(&shost->scan_mutex);
175 return;
176 }
177 spin_unlock_irqrestore(shost->host_lock, flags);
178
179 scsi_autopm_get_host(shost);
180 flush_workqueue(shost->tmf_work_q);
181 scsi_forget_host(shost);
182 mutex_unlock(&shost->scan_mutex);
183 scsi_proc_host_rm(shost);
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 if (!shost->shost_gendev.parent)
233 shost->shost_gendev.parent = dev ? dev : &platform_bus;
234 if (!dma_dev)
235 dma_dev = shost->shost_gendev.parent;
236
237 shost->dma_dev = dma_dev;
238
239 error = scsi_mq_setup_tags(shost);
240 if (error)
241 goto fail;
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 scsi_proc_hostdir_rm(shost->hostt);
326
327 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
328 rcu_barrier();
329
330 if (shost->tmf_work_q)
331 destroy_workqueue(shost->tmf_work_q);
332 if (shost->ehandler)
333 kthread_stop(shost->ehandler);
334 if (shost->work_q)
335 destroy_workqueue(shost->work_q);
336
337 if (shost->shost_state == SHOST_CREATED) {
338 /*
339 * Free the shost_dev device name here if scsi_host_alloc()
340 * and scsi_host_put() have been called but neither
341 * scsi_host_add() nor scsi_host_remove() has been called.
342 * This avoids that the memory allocated for the shost_dev
343 * name is leaked.
344 */
345 kfree(dev_name(&shost->shost_dev));
346 }
347
348 if (shost->tag_set.tags)
349 scsi_mq_destroy_tags(shost);
350
351 kfree(shost->shost_data);
352
353 ida_simple_remove(&host_index_ida, shost->host_no);
354
355 if (shost->shost_state != SHOST_CREATED)
356 put_device(parent);
357 kfree(shost);
358 }
359
360 static struct device_type scsi_host_type = {
361 .name = "scsi_host",
362 .release = scsi_host_dev_release,
363 };
364
365 /**
366 * scsi_host_alloc - register a scsi host adapter instance.
367 * @sht: pointer to scsi host template
368 * @privsize: extra bytes to allocate for driver
369 *
370 * Note:
371 * Allocate a new Scsi_Host and perform basic initialization.
372 * The host is not published to the scsi midlayer until scsi_add_host
373 * is called.
374 *
375 * Return value:
376 * Pointer to a new Scsi_Host
377 **/
scsi_host_alloc(struct scsi_host_template * sht,int privsize)378 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
379 {
380 struct Scsi_Host *shost;
381 int index;
382
383 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
384 if (!shost)
385 return NULL;
386
387 shost->host_lock = &shost->default_lock;
388 spin_lock_init(shost->host_lock);
389 shost->shost_state = SHOST_CREATED;
390 INIT_LIST_HEAD(&shost->__devices);
391 INIT_LIST_HEAD(&shost->__targets);
392 INIT_LIST_HEAD(&shost->eh_abort_list);
393 INIT_LIST_HEAD(&shost->eh_cmd_q);
394 INIT_LIST_HEAD(&shost->starved_list);
395 init_waitqueue_head(&shost->host_wait);
396 mutex_init(&shost->scan_mutex);
397
398 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
399 if (index < 0) {
400 kfree(shost);
401 return NULL;
402 }
403 shost->host_no = index;
404
405 shost->dma_channel = 0xff;
406
407 /* These three are default values which can be overridden */
408 shost->max_channel = 0;
409 shost->max_id = 8;
410 shost->max_lun = 8;
411
412 /* Give each shost a default transportt */
413 shost->transportt = &blank_transport_template;
414
415 /*
416 * All drivers right now should be able to handle 12 byte
417 * commands. Every so often there are requests for 16 byte
418 * commands, but individual low-level drivers need to certify that
419 * they actually do something sensible with such commands.
420 */
421 shost->max_cmd_len = 12;
422 shost->hostt = sht;
423 shost->this_id = sht->this_id;
424 shost->can_queue = sht->can_queue;
425 shost->sg_tablesize = sht->sg_tablesize;
426 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
427 shost->cmd_per_lun = sht->cmd_per_lun;
428 shost->no_write_same = sht->no_write_same;
429 shost->host_tagset = sht->host_tagset;
430
431 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
432 shost->eh_deadline = -1;
433 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
434 shost_printk(KERN_WARNING, shost,
435 "eh_deadline %u too large, setting to %u\n",
436 shost_eh_deadline, INT_MAX / HZ);
437 shost->eh_deadline = INT_MAX;
438 } else
439 shost->eh_deadline = shost_eh_deadline * HZ;
440
441 if (sht->supported_mode == MODE_UNKNOWN)
442 /* means we didn't set it ... default to INITIATOR */
443 shost->active_mode = MODE_INITIATOR;
444 else
445 shost->active_mode = sht->supported_mode;
446
447 if (sht->max_host_blocked)
448 shost->max_host_blocked = sht->max_host_blocked;
449 else
450 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
451
452 /*
453 * If the driver imposes no hard sector transfer limit, start at
454 * machine infinity initially.
455 */
456 if (sht->max_sectors)
457 shost->max_sectors = sht->max_sectors;
458 else
459 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
460
461 if (sht->max_segment_size)
462 shost->max_segment_size = sht->max_segment_size;
463 else
464 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
465
466 /*
467 * assume a 4GB boundary, if not set
468 */
469 if (sht->dma_boundary)
470 shost->dma_boundary = sht->dma_boundary;
471 else
472 shost->dma_boundary = 0xffffffff;
473
474 if (sht->virt_boundary_mask)
475 shost->virt_boundary_mask = sht->virt_boundary_mask;
476
477 device_initialize(&shost->shost_gendev);
478 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
479 shost->shost_gendev.bus = &scsi_bus_type;
480 shost->shost_gendev.type = &scsi_host_type;
481 scsi_enable_async_suspend(&shost->shost_gendev);
482
483 device_initialize(&shost->shost_dev);
484 shost->shost_dev.parent = &shost->shost_gendev;
485 shost->shost_dev.class = &shost_class;
486 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
487 shost->shost_dev.groups = sht->shost_groups;
488
489 shost->ehandler = kthread_run(scsi_error_handler, shost,
490 "scsi_eh_%d", shost->host_no);
491 if (IS_ERR(shost->ehandler)) {
492 shost_printk(KERN_WARNING, shost,
493 "error handler thread failed to spawn, error = %ld\n",
494 PTR_ERR(shost->ehandler));
495 shost->ehandler = NULL;
496 goto fail;
497 }
498
499 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
500 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
501 1, shost->host_no);
502 if (!shost->tmf_work_q) {
503 shost_printk(KERN_WARNING, shost,
504 "failed to create tmf workq\n");
505 goto fail;
506 }
507 scsi_proc_hostdir_add(shost->hostt);
508 return shost;
509 fail:
510 /*
511 * Host state is still SHOST_CREATED and that is enough to release
512 * ->shost_gendev. scsi_host_dev_release() will free
513 * dev_name(&shost->shost_dev).
514 */
515 put_device(&shost->shost_gendev);
516
517 return NULL;
518 }
519 EXPORT_SYMBOL(scsi_host_alloc);
520
__scsi_host_match(struct device * dev,const void * data)521 static int __scsi_host_match(struct device *dev, const void *data)
522 {
523 struct Scsi_Host *p;
524 const unsigned short *hostnum = data;
525
526 p = class_to_shost(dev);
527 return p->host_no == *hostnum;
528 }
529
530 /**
531 * scsi_host_lookup - get a reference to a Scsi_Host by host no
532 * @hostnum: host number to locate
533 *
534 * Return value:
535 * A pointer to located Scsi_Host or NULL.
536 *
537 * The caller must do a scsi_host_put() to drop the reference
538 * that scsi_host_get() took. The put_device() below dropped
539 * the reference from class_find_device().
540 **/
scsi_host_lookup(unsigned short hostnum)541 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
542 {
543 struct device *cdev;
544 struct Scsi_Host *shost = NULL;
545
546 cdev = class_find_device(&shost_class, NULL, &hostnum,
547 __scsi_host_match);
548 if (cdev) {
549 shost = scsi_host_get(class_to_shost(cdev));
550 put_device(cdev);
551 }
552 return shost;
553 }
554 EXPORT_SYMBOL(scsi_host_lookup);
555
556 /**
557 * scsi_host_get - inc a Scsi_Host ref count
558 * @shost: Pointer to Scsi_Host to inc.
559 **/
scsi_host_get(struct Scsi_Host * shost)560 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
561 {
562 if ((shost->shost_state == SHOST_DEL) ||
563 !get_device(&shost->shost_gendev))
564 return NULL;
565 return shost;
566 }
567 EXPORT_SYMBOL(scsi_host_get);
568
scsi_host_check_in_flight(struct request * rq,void * data,bool reserved)569 static bool scsi_host_check_in_flight(struct request *rq, void *data,
570 bool reserved)
571 {
572 int *count = data;
573 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
574
575 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
576 (*count)++;
577
578 return true;
579 }
580
581 /**
582 * scsi_host_busy - Return the host busy counter
583 * @shost: Pointer to Scsi_Host to inc.
584 **/
scsi_host_busy(struct Scsi_Host * shost)585 int scsi_host_busy(struct Scsi_Host *shost)
586 {
587 int cnt = 0;
588
589 blk_mq_tagset_busy_iter(&shost->tag_set,
590 scsi_host_check_in_flight, &cnt);
591 return cnt;
592 }
593 EXPORT_SYMBOL(scsi_host_busy);
594
595 /**
596 * scsi_host_put - dec a Scsi_Host ref count
597 * @shost: Pointer to Scsi_Host to dec.
598 **/
scsi_host_put(struct Scsi_Host * shost)599 void scsi_host_put(struct Scsi_Host *shost)
600 {
601 put_device(&shost->shost_gendev);
602 }
603 EXPORT_SYMBOL(scsi_host_put);
604
scsi_init_hosts(void)605 int scsi_init_hosts(void)
606 {
607 return class_register(&shost_class);
608 }
609
scsi_exit_hosts(void)610 void scsi_exit_hosts(void)
611 {
612 class_unregister(&shost_class);
613 ida_destroy(&host_index_ida);
614 }
615
scsi_is_host_device(const struct device * dev)616 int scsi_is_host_device(const struct device *dev)
617 {
618 return dev->type == &scsi_host_type;
619 }
620 EXPORT_SYMBOL(scsi_is_host_device);
621
622 /**
623 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
624 * @shost: Pointer to Scsi_Host.
625 * @work: Work to queue for execution.
626 *
627 * Return value:
628 * 1 - work queued for execution
629 * 0 - work is already queued
630 * -EINVAL - work queue doesn't exist
631 **/
scsi_queue_work(struct Scsi_Host * shost,struct work_struct * work)632 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
633 {
634 if (unlikely(!shost->work_q)) {
635 shost_printk(KERN_ERR, shost,
636 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
637 "when no workqueue created.\n", shost->hostt->name);
638 dump_stack();
639
640 return -EINVAL;
641 }
642
643 return queue_work(shost->work_q, work);
644 }
645 EXPORT_SYMBOL_GPL(scsi_queue_work);
646
647 /**
648 * scsi_flush_work - Flush a Scsi_Host's workqueue.
649 * @shost: Pointer to Scsi_Host.
650 **/
scsi_flush_work(struct Scsi_Host * shost)651 void scsi_flush_work(struct Scsi_Host *shost)
652 {
653 if (!shost->work_q) {
654 shost_printk(KERN_ERR, shost,
655 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
656 "when no workqueue created.\n", shost->hostt->name);
657 dump_stack();
658 return;
659 }
660
661 flush_workqueue(shost->work_q);
662 }
663 EXPORT_SYMBOL_GPL(scsi_flush_work);
664
complete_all_cmds_iter(struct request * rq,void * data,bool rsvd)665 static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
666 {
667 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
668 enum scsi_host_status status = *(enum scsi_host_status *)data;
669
670 scsi_dma_unmap(scmd);
671 scmd->result = 0;
672 set_host_byte(scmd, status);
673 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,enum scsi_host_status status)687 void scsi_host_complete_all_commands(struct Scsi_Host *shost,
688 enum scsi_host_status 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