1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * scsi_scan.c
4 *
5 * Copyright (C) 2000 Eric Youngdale,
6 * Copyright (C) 2002 Patrick Mansfield
7 *
8 * The general scanning/probing algorithm is as follows, exceptions are
9 * made to it depending on device specific flags, compilation options, and
10 * global variable (boot or module load time) settings.
11 *
12 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
13 * device attached, a scsi_device is allocated and setup for it.
14 *
15 * For every id of every channel on the given host:
16 *
17 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
18 * device or storage attached to LUN 0):
19 *
20 * If LUN 0 has a device attached, allocate and setup a
21 * scsi_device for it.
22 *
23 * If target is SCSI-3 or up, issue a REPORT LUN, and scan
24 * all of the LUNs returned by the REPORT LUN; else,
25 * sequentially scan LUNs up until some maximum is reached,
26 * or a LUN is seen that cannot have a device attached to it.
27 */
28
29 #include <linux/module.h>
30 #include <linux/moduleparam.h>
31 #include <linux/init.h>
32 #include <linux/blkdev.h>
33 #include <linux/delay.h>
34 #include <linux/kthread.h>
35 #include <linux/spinlock.h>
36 #include <linux/async.h>
37 #include <linux/slab.h>
38 #include <asm/unaligned.h>
39
40 #include <scsi/scsi.h>
41 #include <scsi/scsi_cmnd.h>
42 #include <scsi/scsi_device.h>
43 #include <scsi/scsi_driver.h>
44 #include <scsi/scsi_devinfo.h>
45 #include <scsi/scsi_host.h>
46 #include <scsi/scsi_transport.h>
47 #include <scsi/scsi_dh.h>
48 #include <scsi/scsi_eh.h>
49
50 #include "scsi_priv.h"
51 #include "scsi_logging.h"
52
53 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
54 " SCSI scanning, some SCSI devices might not be configured\n"
55
56 /*
57 * Default timeout
58 */
59 #define SCSI_TIMEOUT (2*HZ)
60 #define SCSI_REPORT_LUNS_TIMEOUT (30*HZ)
61
62 /*
63 * Prefix values for the SCSI id's (stored in sysfs name field)
64 */
65 #define SCSI_UID_SER_NUM 'S'
66 #define SCSI_UID_UNKNOWN 'Z'
67
68 /*
69 * Return values of some of the scanning functions.
70 *
71 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
72 * includes allocation or general failures preventing IO from being sent.
73 *
74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
75 * on the given LUN.
76 *
77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
78 * given LUN.
79 */
80 #define SCSI_SCAN_NO_RESPONSE 0
81 #define SCSI_SCAN_TARGET_PRESENT 1
82 #define SCSI_SCAN_LUN_PRESENT 2
83
84 static const char *scsi_null_device_strs = "nullnullnullnull";
85
86 #define MAX_SCSI_LUNS 512
87
88 static u64 max_scsi_luns = MAX_SCSI_LUNS;
89
90 module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);
91 MODULE_PARM_DESC(max_luns,
92 "last scsi LUN (should be between 1 and 2^64-1)");
93
94 #ifdef CONFIG_SCSI_SCAN_ASYNC
95 #define SCSI_SCAN_TYPE_DEFAULT "async"
96 #else
97 #define SCSI_SCAN_TYPE_DEFAULT "sync"
98 #endif
99
100 char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT;
101
102 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type),
103 S_IRUGO|S_IWUSR);
104 MODULE_PARM_DESC(scan, "sync, async, manual, or none. "
105 "Setting to 'manual' disables automatic scanning, but allows "
106 "for manual device scan via the 'scan' sysfs attribute.");
107
108 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
109
110 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
111 MODULE_PARM_DESC(inq_timeout,
112 "Timeout (in seconds) waiting for devices to answer INQUIRY."
113 " Default is 20. Some devices may need more; most need less.");
114
115 /* This lock protects only this list */
116 static DEFINE_SPINLOCK(async_scan_lock);
117 static LIST_HEAD(scanning_hosts);
118
119 struct async_scan_data {
120 struct list_head list;
121 struct Scsi_Host *shost;
122 struct completion prev_finished;
123 };
124
125 /**
126 * scsi_complete_async_scans - Wait for asynchronous scans to complete
127 *
128 * When this function returns, any host which started scanning before
129 * this function was called will have finished its scan. Hosts which
130 * started scanning after this function was called may or may not have
131 * finished.
132 */
scsi_complete_async_scans(void)133 int scsi_complete_async_scans(void)
134 {
135 struct async_scan_data *data;
136
137 do {
138 if (list_empty(&scanning_hosts))
139 return 0;
140 /* If we can't get memory immediately, that's OK. Just
141 * sleep a little. Even if we never get memory, the async
142 * scans will finish eventually.
143 */
144 data = kmalloc(sizeof(*data), GFP_KERNEL);
145 if (!data)
146 msleep(1);
147 } while (!data);
148
149 data->shost = NULL;
150 init_completion(&data->prev_finished);
151
152 spin_lock(&async_scan_lock);
153 /* Check that there's still somebody else on the list */
154 if (list_empty(&scanning_hosts))
155 goto done;
156 list_add_tail(&data->list, &scanning_hosts);
157 spin_unlock(&async_scan_lock);
158
159 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
160 wait_for_completion(&data->prev_finished);
161
162 spin_lock(&async_scan_lock);
163 list_del(&data->list);
164 if (!list_empty(&scanning_hosts)) {
165 struct async_scan_data *next = list_entry(scanning_hosts.next,
166 struct async_scan_data, list);
167 complete(&next->prev_finished);
168 }
169 done:
170 spin_unlock(&async_scan_lock);
171
172 kfree(data);
173 return 0;
174 }
175
176 /**
177 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
178 * @sdev: scsi device to send command to
179 * @result: area to store the result of the MODE SENSE
180 *
181 * Description:
182 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
183 * Called for BLIST_KEY devices.
184 **/
scsi_unlock_floptical(struct scsi_device * sdev,unsigned char * result)185 static void scsi_unlock_floptical(struct scsi_device *sdev,
186 unsigned char *result)
187 {
188 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
189
190 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
191 scsi_cmd[0] = MODE_SENSE;
192 scsi_cmd[1] = 0;
193 scsi_cmd[2] = 0x2e;
194 scsi_cmd[3] = 0;
195 scsi_cmd[4] = 0x2a; /* size */
196 scsi_cmd[5] = 0;
197 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
198 SCSI_TIMEOUT, 3, NULL);
199 }
200
201 /**
202 * scsi_alloc_sdev - allocate and setup a scsi_Device
203 * @starget: which target to allocate a &scsi_device for
204 * @lun: which lun
205 * @hostdata: usually NULL and set by ->slave_alloc instead
206 *
207 * Description:
208 * Allocate, initialize for io, and return a pointer to a scsi_Device.
209 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
210 * adds scsi_Device to the appropriate list.
211 *
212 * Return value:
213 * scsi_Device pointer, or NULL on failure.
214 **/
scsi_alloc_sdev(struct scsi_target * starget,u64 lun,void * hostdata)215 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
216 u64 lun, void *hostdata)
217 {
218 unsigned int depth;
219 struct scsi_device *sdev;
220 int display_failure_msg = 1, ret;
221 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
222
223 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
224 GFP_KERNEL);
225 if (!sdev)
226 goto out;
227
228 sdev->vendor = scsi_null_device_strs;
229 sdev->model = scsi_null_device_strs;
230 sdev->rev = scsi_null_device_strs;
231 sdev->host = shost;
232 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
233 sdev->id = starget->id;
234 sdev->lun = lun;
235 sdev->channel = starget->channel;
236 mutex_init(&sdev->state_mutex);
237 sdev->sdev_state = SDEV_CREATED;
238 INIT_LIST_HEAD(&sdev->siblings);
239 INIT_LIST_HEAD(&sdev->same_target_siblings);
240 INIT_LIST_HEAD(&sdev->starved_entry);
241 INIT_LIST_HEAD(&sdev->event_list);
242 spin_lock_init(&sdev->list_lock);
243 mutex_init(&sdev->inquiry_mutex);
244 INIT_WORK(&sdev->event_work, scsi_evt_thread);
245 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
246
247 sdev->sdev_gendev.parent = get_device(&starget->dev);
248 sdev->sdev_target = starget;
249
250 /* usually NULL and set by ->slave_alloc instead */
251 sdev->hostdata = hostdata;
252
253 /* if the device needs this changing, it may do so in the
254 * slave_configure function */
255 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
256
257 /*
258 * Some low level driver could use device->type
259 */
260 sdev->type = -1;
261
262 /*
263 * Assume that the device will have handshaking problems,
264 * and then fix this field later if it turns out it
265 * doesn't
266 */
267 sdev->borken = 1;
268
269 sdev->request_queue = scsi_mq_alloc_queue(sdev);
270 if (!sdev->request_queue) {
271 /* release fn is set up in scsi_sysfs_device_initialise, so
272 * have to free and put manually here */
273 put_device(&starget->dev);
274 kfree(sdev);
275 goto out;
276 }
277 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
278 sdev->request_queue->queuedata = sdev;
279
280 depth = sdev->host->cmd_per_lun ?: 1;
281
282 /*
283 * Use .can_queue as budget map's depth because we have to
284 * support adjusting queue depth from sysfs. Meantime use
285 * default device queue depth to figure out sbitmap shift
286 * since we use this queue depth most of times.
287 */
288 if (sbitmap_init_node(&sdev->budget_map,
289 scsi_device_max_queue_depth(sdev),
290 sbitmap_calculate_shift(depth),
291 GFP_KERNEL, sdev->request_queue->node,
292 false, true)) {
293 put_device(&starget->dev);
294 kfree(sdev);
295 goto out;
296 }
297
298 scsi_change_queue_depth(sdev, depth);
299
300 scsi_sysfs_device_initialize(sdev);
301
302 if (shost->hostt->slave_alloc) {
303 ret = shost->hostt->slave_alloc(sdev);
304 if (ret) {
305 /*
306 * if LLDD reports slave not present, don't clutter
307 * console with alloc failure messages
308 */
309 if (ret == -ENXIO)
310 display_failure_msg = 0;
311 goto out_device_destroy;
312 }
313 }
314
315 return sdev;
316
317 out_device_destroy:
318 __scsi_remove_device(sdev);
319 out:
320 if (display_failure_msg)
321 printk(ALLOC_FAILURE_MSG, __func__);
322 return NULL;
323 }
324
scsi_target_destroy(struct scsi_target * starget)325 static void scsi_target_destroy(struct scsi_target *starget)
326 {
327 struct device *dev = &starget->dev;
328 struct Scsi_Host *shost = dev_to_shost(dev->parent);
329 unsigned long flags;
330
331 BUG_ON(starget->state == STARGET_DEL);
332 starget->state = STARGET_DEL;
333 transport_destroy_device(dev);
334 spin_lock_irqsave(shost->host_lock, flags);
335 if (shost->hostt->target_destroy)
336 shost->hostt->target_destroy(starget);
337 list_del_init(&starget->siblings);
338 spin_unlock_irqrestore(shost->host_lock, flags);
339 put_device(dev);
340 }
341
scsi_target_dev_release(struct device * dev)342 static void scsi_target_dev_release(struct device *dev)
343 {
344 struct device *parent = dev->parent;
345 struct scsi_target *starget = to_scsi_target(dev);
346
347 kfree(starget);
348 put_device(parent);
349 }
350
351 static struct device_type scsi_target_type = {
352 .name = "scsi_target",
353 .release = scsi_target_dev_release,
354 };
355
scsi_is_target_device(const struct device * dev)356 int scsi_is_target_device(const struct device *dev)
357 {
358 return dev->type == &scsi_target_type;
359 }
360 EXPORT_SYMBOL(scsi_is_target_device);
361
__scsi_find_target(struct device * parent,int channel,uint id)362 static struct scsi_target *__scsi_find_target(struct device *parent,
363 int channel, uint id)
364 {
365 struct scsi_target *starget, *found_starget = NULL;
366 struct Scsi_Host *shost = dev_to_shost(parent);
367 /*
368 * Search for an existing target for this sdev.
369 */
370 list_for_each_entry(starget, &shost->__targets, siblings) {
371 if (starget->id == id &&
372 starget->channel == channel) {
373 found_starget = starget;
374 break;
375 }
376 }
377 if (found_starget)
378 get_device(&found_starget->dev);
379
380 return found_starget;
381 }
382
383 /**
384 * scsi_target_reap_ref_release - remove target from visibility
385 * @kref: the reap_ref in the target being released
386 *
387 * Called on last put of reap_ref, which is the indication that no device
388 * under this target is visible anymore, so render the target invisible in
389 * sysfs. Note: we have to be in user context here because the target reaps
390 * should be done in places where the scsi device visibility is being removed.
391 */
scsi_target_reap_ref_release(struct kref * kref)392 static void scsi_target_reap_ref_release(struct kref *kref)
393 {
394 struct scsi_target *starget
395 = container_of(kref, struct scsi_target, reap_ref);
396
397 /*
398 * if we get here and the target is still in a CREATED state that
399 * means it was allocated but never made visible (because a scan
400 * turned up no LUNs), so don't call device_del() on it.
401 */
402 if ((starget->state != STARGET_CREATED) &&
403 (starget->state != STARGET_CREATED_REMOVE)) {
404 transport_remove_device(&starget->dev);
405 device_del(&starget->dev);
406 }
407 scsi_target_destroy(starget);
408 }
409
scsi_target_reap_ref_put(struct scsi_target * starget)410 static void scsi_target_reap_ref_put(struct scsi_target *starget)
411 {
412 kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
413 }
414
415 /**
416 * scsi_alloc_target - allocate a new or find an existing target
417 * @parent: parent of the target (need not be a scsi host)
418 * @channel: target channel number (zero if no channels)
419 * @id: target id number
420 *
421 * Return an existing target if one exists, provided it hasn't already
422 * gone into STARGET_DEL state, otherwise allocate a new target.
423 *
424 * The target is returned with an incremented reference, so the caller
425 * is responsible for both reaping and doing a last put
426 */
scsi_alloc_target(struct device * parent,int channel,uint id)427 static struct scsi_target *scsi_alloc_target(struct device *parent,
428 int channel, uint id)
429 {
430 struct Scsi_Host *shost = dev_to_shost(parent);
431 struct device *dev = NULL;
432 unsigned long flags;
433 const int size = sizeof(struct scsi_target)
434 + shost->transportt->target_size;
435 struct scsi_target *starget;
436 struct scsi_target *found_target;
437 int error, ref_got;
438
439 starget = kzalloc(size, GFP_KERNEL);
440 if (!starget) {
441 printk(KERN_ERR "%s: allocation failure\n", __func__);
442 return NULL;
443 }
444 dev = &starget->dev;
445 device_initialize(dev);
446 kref_init(&starget->reap_ref);
447 dev->parent = get_device(parent);
448 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
449 dev->bus = &scsi_bus_type;
450 dev->type = &scsi_target_type;
451 starget->id = id;
452 starget->channel = channel;
453 starget->can_queue = 0;
454 INIT_LIST_HEAD(&starget->siblings);
455 INIT_LIST_HEAD(&starget->devices);
456 starget->state = STARGET_CREATED;
457 starget->scsi_level = SCSI_2;
458 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
459 retry:
460 spin_lock_irqsave(shost->host_lock, flags);
461
462 found_target = __scsi_find_target(parent, channel, id);
463 if (found_target)
464 goto found;
465
466 list_add_tail(&starget->siblings, &shost->__targets);
467 spin_unlock_irqrestore(shost->host_lock, flags);
468 /* allocate and add */
469 transport_setup_device(dev);
470 if (shost->hostt->target_alloc) {
471 error = shost->hostt->target_alloc(starget);
472
473 if(error) {
474 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
475 /* don't want scsi_target_reap to do the final
476 * put because it will be under the host lock */
477 scsi_target_destroy(starget);
478 return NULL;
479 }
480 }
481 get_device(dev);
482
483 return starget;
484
485 found:
486 /*
487 * release routine already fired if kref is zero, so if we can still
488 * take the reference, the target must be alive. If we can't, it must
489 * be dying and we need to wait for a new target
490 */
491 ref_got = kref_get_unless_zero(&found_target->reap_ref);
492
493 spin_unlock_irqrestore(shost->host_lock, flags);
494 if (ref_got) {
495 put_device(dev);
496 return found_target;
497 }
498 /*
499 * Unfortunately, we found a dying target; need to wait until it's
500 * dead before we can get a new one. There is an anomaly here. We
501 * *should* call scsi_target_reap() to balance the kref_get() of the
502 * reap_ref above. However, since the target being released, it's
503 * already invisible and the reap_ref is irrelevant. If we call
504 * scsi_target_reap() we might spuriously do another device_del() on
505 * an already invisible target.
506 */
507 put_device(&found_target->dev);
508 /*
509 * length of time is irrelevant here, we just want to yield the CPU
510 * for a tick to avoid busy waiting for the target to die.
511 */
512 msleep(1);
513 goto retry;
514 }
515
516 /**
517 * scsi_target_reap - check to see if target is in use and destroy if not
518 * @starget: target to be checked
519 *
520 * This is used after removing a LUN or doing a last put of the target
521 * it checks atomically that nothing is using the target and removes
522 * it if so.
523 */
scsi_target_reap(struct scsi_target * starget)524 void scsi_target_reap(struct scsi_target *starget)
525 {
526 /*
527 * serious problem if this triggers: STARGET_DEL is only set in the if
528 * the reap_ref drops to zero, so we're trying to do another final put
529 * on an already released kref
530 */
531 BUG_ON(starget->state == STARGET_DEL);
532 scsi_target_reap_ref_put(starget);
533 }
534
535 /**
536 * scsi_sanitize_inquiry_string - remove non-graphical chars from an
537 * INQUIRY result string
538 * @s: INQUIRY result string to sanitize
539 * @len: length of the string
540 *
541 * Description:
542 * The SCSI spec says that INQUIRY vendor, product, and revision
543 * strings must consist entirely of graphic ASCII characters,
544 * padded on the right with spaces. Since not all devices obey
545 * this rule, we will replace non-graphic or non-ASCII characters
546 * with spaces. Exception: a NUL character is interpreted as a
547 * string terminator, so all the following characters are set to
548 * spaces.
549 **/
scsi_sanitize_inquiry_string(unsigned char * s,int len)550 void scsi_sanitize_inquiry_string(unsigned char *s, int len)
551 {
552 int terminated = 0;
553
554 for (; len > 0; (--len, ++s)) {
555 if (*s == 0)
556 terminated = 1;
557 if (terminated || *s < 0x20 || *s > 0x7e)
558 *s = ' ';
559 }
560 }
561 EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
562
563 /**
564 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
565 * @sdev: scsi_device to probe
566 * @inq_result: area to store the INQUIRY result
567 * @result_len: len of inq_result
568 * @bflags: store any bflags found here
569 *
570 * Description:
571 * Probe the lun associated with @req using a standard SCSI INQUIRY;
572 *
573 * If the INQUIRY is successful, zero is returned and the
574 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
575 * are copied to the scsi_device any flags value is stored in *@bflags.
576 **/
scsi_probe_lun(struct scsi_device * sdev,unsigned char * inq_result,int result_len,blist_flags_t * bflags)577 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
578 int result_len, blist_flags_t *bflags)
579 {
580 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
581 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
582 int response_len = 0;
583 int pass, count, result;
584 struct scsi_sense_hdr sshdr;
585
586 *bflags = 0;
587
588 /* Perform up to 3 passes. The first pass uses a conservative
589 * transfer length of 36 unless sdev->inquiry_len specifies a
590 * different value. */
591 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
592 try_inquiry_len = first_inquiry_len;
593 pass = 1;
594
595 next_pass:
596 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
597 "scsi scan: INQUIRY pass %d length %d\n",
598 pass, try_inquiry_len));
599
600 /* Each pass gets up to three chances to ignore Unit Attention */
601 for (count = 0; count < 3; ++count) {
602 int resid;
603
604 memset(scsi_cmd, 0, 6);
605 scsi_cmd[0] = INQUIRY;
606 scsi_cmd[4] = (unsigned char) try_inquiry_len;
607
608 memset(inq_result, 0, try_inquiry_len);
609
610 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
611 inq_result, try_inquiry_len, &sshdr,
612 HZ / 2 + HZ * scsi_inq_timeout, 3,
613 &resid);
614
615 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
616 "scsi scan: INQUIRY %s with code 0x%x\n",
617 result ? "failed" : "successful", result));
618
619 if (result) {
620 /*
621 * not-ready to ready transition [asc/ascq=0x28/0x0]
622 * or power-on, reset [asc/ascq=0x29/0x0], continue.
623 * INQUIRY should not yield UNIT_ATTENTION
624 * but many buggy devices do so anyway.
625 */
626 if (driver_byte(result) == DRIVER_SENSE &&
627 scsi_sense_valid(&sshdr)) {
628 if ((sshdr.sense_key == UNIT_ATTENTION) &&
629 ((sshdr.asc == 0x28) ||
630 (sshdr.asc == 0x29)) &&
631 (sshdr.ascq == 0))
632 continue;
633 }
634 } else {
635 /*
636 * if nothing was transferred, we try
637 * again. It's a workaround for some USB
638 * devices.
639 */
640 if (resid == try_inquiry_len)
641 continue;
642 }
643 break;
644 }
645
646 if (result == 0) {
647 scsi_sanitize_inquiry_string(&inq_result[8], 8);
648 scsi_sanitize_inquiry_string(&inq_result[16], 16);
649 scsi_sanitize_inquiry_string(&inq_result[32], 4);
650
651 response_len = inq_result[4] + 5;
652 if (response_len > 255)
653 response_len = first_inquiry_len; /* sanity */
654
655 /*
656 * Get any flags for this device.
657 *
658 * XXX add a bflags to scsi_device, and replace the
659 * corresponding bit fields in scsi_device, so bflags
660 * need not be passed as an argument.
661 */
662 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
663 &inq_result[16]);
664
665 /* When the first pass succeeds we gain information about
666 * what larger transfer lengths might work. */
667 if (pass == 1) {
668 if (BLIST_INQUIRY_36 & *bflags)
669 next_inquiry_len = 36;
670 else if (sdev->inquiry_len)
671 next_inquiry_len = sdev->inquiry_len;
672 else
673 next_inquiry_len = response_len;
674
675 /* If more data is available perform the second pass */
676 if (next_inquiry_len > try_inquiry_len) {
677 try_inquiry_len = next_inquiry_len;
678 pass = 2;
679 goto next_pass;
680 }
681 }
682
683 } else if (pass == 2) {
684 sdev_printk(KERN_INFO, sdev,
685 "scsi scan: %d byte inquiry failed. "
686 "Consider BLIST_INQUIRY_36 for this device\n",
687 try_inquiry_len);
688
689 /* If this pass failed, the third pass goes back and transfers
690 * the same amount as we successfully got in the first pass. */
691 try_inquiry_len = first_inquiry_len;
692 pass = 3;
693 goto next_pass;
694 }
695
696 /* If the last transfer attempt got an error, assume the
697 * peripheral doesn't exist or is dead. */
698 if (result)
699 return -EIO;
700
701 /* Don't report any more data than the device says is valid */
702 sdev->inquiry_len = min(try_inquiry_len, response_len);
703
704 /*
705 * XXX Abort if the response length is less than 36? If less than
706 * 32, the lookup of the device flags (above) could be invalid,
707 * and it would be possible to take an incorrect action - we do
708 * not want to hang because of a short INQUIRY. On the flip side,
709 * if the device is spun down or becoming ready (and so it gives a
710 * short INQUIRY), an abort here prevents any further use of the
711 * device, including spin up.
712 *
713 * On the whole, the best approach seems to be to assume the first
714 * 36 bytes are valid no matter what the device says. That's
715 * better than copying < 36 bytes to the inquiry-result buffer
716 * and displaying garbage for the Vendor, Product, or Revision
717 * strings.
718 */
719 if (sdev->inquiry_len < 36) {
720 if (!sdev->host->short_inquiry) {
721 shost_printk(KERN_INFO, sdev->host,
722 "scsi scan: INQUIRY result too short (%d),"
723 " using 36\n", sdev->inquiry_len);
724 sdev->host->short_inquiry = 1;
725 }
726 sdev->inquiry_len = 36;
727 }
728
729 /*
730 * Related to the above issue:
731 *
732 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
733 * and if not ready, sent a START_STOP to start (maybe spin up) and
734 * then send the INQUIRY again, since the INQUIRY can change after
735 * a device is initialized.
736 *
737 * Ideally, start a device if explicitly asked to do so. This
738 * assumes that a device is spun up on power on, spun down on
739 * request, and then spun up on request.
740 */
741
742 /*
743 * The scanning code needs to know the scsi_level, even if no
744 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
745 * non-zero LUNs can be scanned.
746 */
747 sdev->scsi_level = inq_result[2] & 0x07;
748 if (sdev->scsi_level >= 2 ||
749 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
750 sdev->scsi_level++;
751 sdev->sdev_target->scsi_level = sdev->scsi_level;
752
753 /*
754 * If SCSI-2 or lower, and if the transport requires it,
755 * store the LUN value in CDB[1].
756 */
757 sdev->lun_in_cdb = 0;
758 if (sdev->scsi_level <= SCSI_2 &&
759 sdev->scsi_level != SCSI_UNKNOWN &&
760 !sdev->host->no_scsi2_lun_in_cdb)
761 sdev->lun_in_cdb = 1;
762
763 return 0;
764 }
765
766 /**
767 * scsi_add_lun - allocate and fully initialze a scsi_device
768 * @sdev: holds information to be stored in the new scsi_device
769 * @inq_result: holds the result of a previous INQUIRY to the LUN
770 * @bflags: black/white list flag
771 * @async: 1 if this device is being scanned asynchronously
772 *
773 * Description:
774 * Initialize the scsi_device @sdev. Optionally set fields based
775 * on values in *@bflags.
776 *
777 * Return:
778 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
779 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
780 **/
scsi_add_lun(struct scsi_device * sdev,unsigned char * inq_result,blist_flags_t * bflags,int async)781 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
782 blist_flags_t *bflags, int async)
783 {
784 int ret;
785
786 /*
787 * XXX do not save the inquiry, since it can change underneath us,
788 * save just vendor/model/rev.
789 *
790 * Rather than save it and have an ioctl that retrieves the saved
791 * value, have an ioctl that executes the same INQUIRY code used
792 * in scsi_probe_lun, let user level programs doing INQUIRY
793 * scanning run at their own risk, or supply a user level program
794 * that can correctly scan.
795 */
796
797 /*
798 * Copy at least 36 bytes of INQUIRY data, so that we don't
799 * dereference unallocated memory when accessing the Vendor,
800 * Product, and Revision strings. Badly behaved devices may set
801 * the INQUIRY Additional Length byte to a small value, indicating
802 * these strings are invalid, but often they contain plausible data
803 * nonetheless. It doesn't matter if the device sent < 36 bytes
804 * total, since scsi_probe_lun() initializes inq_result with 0s.
805 */
806 sdev->inquiry = kmemdup(inq_result,
807 max_t(size_t, sdev->inquiry_len, 36),
808 GFP_KERNEL);
809 if (sdev->inquiry == NULL)
810 return SCSI_SCAN_NO_RESPONSE;
811
812 sdev->vendor = (char *) (sdev->inquiry + 8);
813 sdev->model = (char *) (sdev->inquiry + 16);
814 sdev->rev = (char *) (sdev->inquiry + 32);
815
816 if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
817 /*
818 * sata emulation layer device. This is a hack to work around
819 * the SATL power management specifications which state that
820 * when the SATL detects the device has gone into standby
821 * mode, it shall respond with NOT READY.
822 */
823 sdev->allow_restart = 1;
824 }
825
826 if (*bflags & BLIST_ISROM) {
827 sdev->type = TYPE_ROM;
828 sdev->removable = 1;
829 } else {
830 sdev->type = (inq_result[0] & 0x1f);
831 sdev->removable = (inq_result[1] & 0x80) >> 7;
832
833 /*
834 * some devices may respond with wrong type for
835 * well-known logical units. Force well-known type
836 * to enumerate them correctly.
837 */
838 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
839 sdev_printk(KERN_WARNING, sdev,
840 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
841 __func__, sdev->type, (unsigned int)sdev->lun);
842 sdev->type = TYPE_WLUN;
843 }
844
845 }
846
847 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
848 /* RBC and MMC devices can return SCSI-3 compliance and yet
849 * still not support REPORT LUNS, so make them act as
850 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
851 * specifically set */
852 if ((*bflags & BLIST_REPORTLUN2) == 0)
853 *bflags |= BLIST_NOREPORTLUN;
854 }
855
856 /*
857 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
858 * spec says: The device server is capable of supporting the
859 * specified peripheral device type on this logical unit. However,
860 * the physical device is not currently connected to this logical
861 * unit.
862 *
863 * The above is vague, as it implies that we could treat 001 and
864 * 011 the same. Stay compatible with previous code, and create a
865 * scsi_device for a PQ of 1
866 *
867 * Don't set the device offline here; rather let the upper
868 * level drivers eval the PQ to decide whether they should
869 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
870 */
871
872 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
873 sdev->lockable = sdev->removable;
874 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
875
876 if (sdev->scsi_level >= SCSI_3 ||
877 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
878 sdev->ppr = 1;
879 if (inq_result[7] & 0x60)
880 sdev->wdtr = 1;
881 if (inq_result[7] & 0x10)
882 sdev->sdtr = 1;
883
884 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
885 "ANSI: %d%s\n", scsi_device_type(sdev->type),
886 sdev->vendor, sdev->model, sdev->rev,
887 sdev->inq_periph_qual, inq_result[2] & 0x07,
888 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
889
890 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
891 !(*bflags & BLIST_NOTQ)) {
892 sdev->tagged_supported = 1;
893 sdev->simple_tags = 1;
894 }
895
896 /*
897 * Some devices (Texel CD ROM drives) have handshaking problems
898 * when used with the Seagate controllers. borken is initialized
899 * to 1, and then set it to 0 here.
900 */
901 if ((*bflags & BLIST_BORKEN) == 0)
902 sdev->borken = 0;
903
904 if (*bflags & BLIST_NO_ULD_ATTACH)
905 sdev->no_uld_attach = 1;
906
907 /*
908 * Apparently some really broken devices (contrary to the SCSI
909 * standards) need to be selected without asserting ATN
910 */
911 if (*bflags & BLIST_SELECT_NO_ATN)
912 sdev->select_no_atn = 1;
913
914 /*
915 * Maximum 512 sector transfer length
916 * broken RA4x00 Compaq Disk Array
917 */
918 if (*bflags & BLIST_MAX_512)
919 blk_queue_max_hw_sectors(sdev->request_queue, 512);
920 /*
921 * Max 1024 sector transfer length for targets that report incorrect
922 * max/optimal lengths and relied on the old block layer safe default
923 */
924 else if (*bflags & BLIST_MAX_1024)
925 blk_queue_max_hw_sectors(sdev->request_queue, 1024);
926
927 /*
928 * Some devices may not want to have a start command automatically
929 * issued when a device is added.
930 */
931 if (*bflags & BLIST_NOSTARTONADD)
932 sdev->no_start_on_add = 1;
933
934 if (*bflags & BLIST_SINGLELUN)
935 scsi_target(sdev)->single_lun = 1;
936
937 sdev->use_10_for_rw = 1;
938
939 /* some devices don't like REPORT SUPPORTED OPERATION CODES
940 * and will simply timeout causing sd_mod init to take a very
941 * very long time */
942 if (*bflags & BLIST_NO_RSOC)
943 sdev->no_report_opcodes = 1;
944
945 /* set the device running here so that slave configure
946 * may do I/O */
947 mutex_lock(&sdev->state_mutex);
948 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
949 if (ret)
950 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
951 mutex_unlock(&sdev->state_mutex);
952
953 if (ret) {
954 sdev_printk(KERN_ERR, sdev,
955 "in wrong state %s to complete scan\n",
956 scsi_device_state_name(sdev->sdev_state));
957 return SCSI_SCAN_NO_RESPONSE;
958 }
959
960 if (*bflags & BLIST_NOT_LOCKABLE)
961 sdev->lockable = 0;
962
963 if (*bflags & BLIST_RETRY_HWERROR)
964 sdev->retry_hwerror = 1;
965
966 if (*bflags & BLIST_NO_DIF)
967 sdev->no_dif = 1;
968
969 if (*bflags & BLIST_UNMAP_LIMIT_WS)
970 sdev->unmap_limit_for_ws = 1;
971
972 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
973
974 if (*bflags & BLIST_TRY_VPD_PAGES)
975 sdev->try_vpd_pages = 1;
976 else if (*bflags & BLIST_SKIP_VPD_PAGES)
977 sdev->skip_vpd_pages = 1;
978
979 transport_configure_device(&sdev->sdev_gendev);
980
981 if (sdev->host->hostt->slave_configure) {
982 ret = sdev->host->hostt->slave_configure(sdev);
983 if (ret) {
984 /*
985 * if LLDD reports slave not present, don't clutter
986 * console with alloc failure messages
987 */
988 if (ret != -ENXIO) {
989 sdev_printk(KERN_ERR, sdev,
990 "failed to configure device\n");
991 }
992 return SCSI_SCAN_NO_RESPONSE;
993 }
994 }
995
996 if (sdev->scsi_level >= SCSI_3)
997 scsi_attach_vpd(sdev);
998
999 sdev->max_queue_depth = sdev->queue_depth;
1000 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth);
1001 sdev->sdev_bflags = *bflags;
1002
1003 /*
1004 * Ok, the device is now all set up, we can
1005 * register it and tell the rest of the kernel
1006 * about it.
1007 */
1008 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
1009 return SCSI_SCAN_NO_RESPONSE;
1010
1011 return SCSI_SCAN_LUN_PRESENT;
1012 }
1013
1014 #ifdef CONFIG_SCSI_LOGGING
1015 /**
1016 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
1017 * @buf: Output buffer with at least end-first+1 bytes of space
1018 * @inq: Inquiry buffer (input)
1019 * @first: Offset of string into inq
1020 * @end: Index after last character in inq
1021 */
scsi_inq_str(unsigned char * buf,unsigned char * inq,unsigned first,unsigned end)1022 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
1023 unsigned first, unsigned end)
1024 {
1025 unsigned term = 0, idx;
1026
1027 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1028 if (inq[idx+first] > ' ') {
1029 buf[idx] = inq[idx+first];
1030 term = idx+1;
1031 } else {
1032 buf[idx] = ' ';
1033 }
1034 }
1035 buf[term] = 0;
1036 return buf;
1037 }
1038 #endif
1039
1040 /**
1041 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1042 * @starget: pointer to target device structure
1043 * @lun: LUN of target device
1044 * @bflagsp: store bflags here if not NULL
1045 * @sdevp: probe the LUN corresponding to this scsi_device
1046 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only
1047 * needed on first scan
1048 * @hostdata: passed to scsi_alloc_sdev()
1049 *
1050 * Description:
1051 * Call scsi_probe_lun, if a LUN with an attached device is found,
1052 * allocate and set it up by calling scsi_add_lun.
1053 *
1054 * Return:
1055 *
1056 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1057 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1058 * attached at the LUN
1059 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1060 **/
scsi_probe_and_add_lun(struct scsi_target * starget,u64 lun,blist_flags_t * bflagsp,struct scsi_device ** sdevp,enum scsi_scan_mode rescan,void * hostdata)1061 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1062 u64 lun, blist_flags_t *bflagsp,
1063 struct scsi_device **sdevp,
1064 enum scsi_scan_mode rescan,
1065 void *hostdata)
1066 {
1067 struct scsi_device *sdev;
1068 unsigned char *result;
1069 blist_flags_t bflags;
1070 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1071 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1072
1073 /*
1074 * The rescan flag is used as an optimization, the first scan of a
1075 * host adapter calls into here with rescan == 0.
1076 */
1077 sdev = scsi_device_lookup_by_target(starget, lun);
1078 if (sdev) {
1079 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) {
1080 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1081 "scsi scan: device exists on %s\n",
1082 dev_name(&sdev->sdev_gendev)));
1083 if (sdevp)
1084 *sdevp = sdev;
1085 else
1086 scsi_device_put(sdev);
1087
1088 if (bflagsp)
1089 *bflagsp = scsi_get_device_flags(sdev,
1090 sdev->vendor,
1091 sdev->model);
1092 return SCSI_SCAN_LUN_PRESENT;
1093 }
1094 scsi_device_put(sdev);
1095 } else
1096 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1097 if (!sdev)
1098 goto out;
1099
1100 result = kmalloc(result_len, GFP_KERNEL);
1101 if (!result)
1102 goto out_free_sdev;
1103
1104 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1105 goto out_free_result;
1106
1107 if (bflagsp)
1108 *bflagsp = bflags;
1109 /*
1110 * result contains valid SCSI INQUIRY data.
1111 */
1112 if ((result[0] >> 5) == 3) {
1113 /*
1114 * For a Peripheral qualifier 3 (011b), the SCSI
1115 * spec says: The device server is not capable of
1116 * supporting a physical device on this logical
1117 * unit.
1118 *
1119 * For disks, this implies that there is no
1120 * logical disk configured at sdev->lun, but there
1121 * is a target id responding.
1122 */
1123 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1124 " peripheral qualifier of 3, device not"
1125 " added\n"))
1126 if (lun == 0) {
1127 SCSI_LOG_SCAN_BUS(1, {
1128 unsigned char vend[9];
1129 unsigned char mod[17];
1130
1131 sdev_printk(KERN_INFO, sdev,
1132 "scsi scan: consider passing scsi_mod."
1133 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1134 scsi_inq_str(vend, result, 8, 16),
1135 scsi_inq_str(mod, result, 16, 32));
1136 });
1137
1138 }
1139
1140 res = SCSI_SCAN_TARGET_PRESENT;
1141 goto out_free_result;
1142 }
1143
1144 /*
1145 * Some targets may set slight variations of PQ and PDT to signal
1146 * that no LUN is present, so don't add sdev in these cases.
1147 * Two specific examples are:
1148 * 1) NetApp targets: return PQ=1, PDT=0x1f
1149 * 2) IBM/2145 targets: return PQ=1, PDT=0
1150 * 3) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1151 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1152 *
1153 * References:
1154 * 1) SCSI SPC-3, pp. 145-146
1155 * PQ=1: "A peripheral device having the specified peripheral
1156 * device type is not connected to this logical unit. However, the
1157 * device server is capable of supporting the specified peripheral
1158 * device type on this logical unit."
1159 * PDT=0x1f: "Unknown or no device type"
1160 * 2) USB UFI 1.0, p. 20
1161 * PDT=00h Direct-access device (floppy)
1162 * PDT=1Fh none (no FDD connected to the requested logical unit)
1163 */
1164 if (((result[0] >> 5) == 1 ||
1165 (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f)) &&
1166 !scsi_is_wlun(lun)) {
1167 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1168 "scsi scan: peripheral device type"
1169 " of 31, no device added\n"));
1170 res = SCSI_SCAN_TARGET_PRESENT;
1171 goto out_free_result;
1172 }
1173
1174 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1175 if (res == SCSI_SCAN_LUN_PRESENT) {
1176 if (bflags & BLIST_KEY) {
1177 sdev->lockable = 0;
1178 scsi_unlock_floptical(sdev, result);
1179 }
1180 }
1181
1182 out_free_result:
1183 kfree(result);
1184 out_free_sdev:
1185 if (res == SCSI_SCAN_LUN_PRESENT) {
1186 if (sdevp) {
1187 if (scsi_device_get(sdev) == 0) {
1188 *sdevp = sdev;
1189 } else {
1190 __scsi_remove_device(sdev);
1191 res = SCSI_SCAN_NO_RESPONSE;
1192 }
1193 }
1194 } else
1195 __scsi_remove_device(sdev);
1196 out:
1197 return res;
1198 }
1199
1200 /**
1201 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1202 * @starget: pointer to target structure to scan
1203 * @bflags: black/white list flag for LUN 0
1204 * @scsi_level: Which version of the standard does this device adhere to
1205 * @rescan: passed to scsi_probe_add_lun()
1206 *
1207 * Description:
1208 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1209 * scanned) to some maximum lun until a LUN is found with no device
1210 * attached. Use the bflags to figure out any oddities.
1211 *
1212 * Modifies sdevscan->lun.
1213 **/
scsi_sequential_lun_scan(struct scsi_target * starget,blist_flags_t bflags,int scsi_level,enum scsi_scan_mode rescan)1214 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1215 blist_flags_t bflags, int scsi_level,
1216 enum scsi_scan_mode rescan)
1217 {
1218 uint max_dev_lun;
1219 u64 sparse_lun, lun;
1220 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1221
1222 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
1223 "scsi scan: Sequential scan\n"));
1224
1225 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1226 /*
1227 * If this device is known to support sparse multiple units,
1228 * override the other settings, and scan all of them. Normally,
1229 * SCSI-3 devices should be scanned via the REPORT LUNS.
1230 */
1231 if (bflags & BLIST_SPARSELUN) {
1232 max_dev_lun = shost->max_lun;
1233 sparse_lun = 1;
1234 } else
1235 sparse_lun = 0;
1236
1237 /*
1238 * If less than SCSI_1_CCS, and no special lun scanning, stop
1239 * scanning; this matches 2.4 behaviour, but could just be a bug
1240 * (to continue scanning a SCSI_1_CCS device).
1241 *
1242 * This test is broken. We might not have any device on lun0 for
1243 * a sparselun device, and if that's the case then how would we
1244 * know the real scsi_level, eh? It might make sense to just not
1245 * scan any SCSI_1 device for non-0 luns, but that check would best
1246 * go into scsi_alloc_sdev() and just have it return null when asked
1247 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1248 *
1249 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1250 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1251 == 0))
1252 return;
1253 */
1254 /*
1255 * If this device is known to support multiple units, override
1256 * the other settings, and scan all of them.
1257 */
1258 if (bflags & BLIST_FORCELUN)
1259 max_dev_lun = shost->max_lun;
1260 /*
1261 * REGAL CDC-4X: avoid hang after LUN 4
1262 */
1263 if (bflags & BLIST_MAX5LUN)
1264 max_dev_lun = min(5U, max_dev_lun);
1265 /*
1266 * Do not scan SCSI-2 or lower device past LUN 7, unless
1267 * BLIST_LARGELUN.
1268 */
1269 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1270 max_dev_lun = min(8U, max_dev_lun);
1271 else
1272 max_dev_lun = min(256U, max_dev_lun);
1273
1274 /*
1275 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1276 * until we reach the max, or no LUN is found and we are not
1277 * sparse_lun.
1278 */
1279 for (lun = 1; lun < max_dev_lun; ++lun)
1280 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1281 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1282 !sparse_lun)
1283 return;
1284 }
1285
1286 /**
1287 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1288 * @starget: which target
1289 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1290 * @rescan: nonzero if we can skip code only needed on first scan
1291 *
1292 * Description:
1293 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1294 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1295 *
1296 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1297 * LUNs even if it's older than SCSI-3.
1298 * If BLIST_NOREPORTLUN is set, return 1 always.
1299 * If BLIST_NOLUN is set, return 0 always.
1300 * If starget->no_report_luns is set, return 1 always.
1301 *
1302 * Return:
1303 * 0: scan completed (or no memory, so further scanning is futile)
1304 * 1: could not scan with REPORT LUN
1305 **/
scsi_report_lun_scan(struct scsi_target * starget,blist_flags_t bflags,enum scsi_scan_mode rescan)1306 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags,
1307 enum scsi_scan_mode rescan)
1308 {
1309 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1310 unsigned int length;
1311 u64 lun;
1312 unsigned int num_luns;
1313 unsigned int retries;
1314 int result;
1315 struct scsi_lun *lunp, *lun_data;
1316 struct scsi_sense_hdr sshdr;
1317 struct scsi_device *sdev;
1318 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1319 int ret = 0;
1320
1321 /*
1322 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1323 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1324 * support more than 8 LUNs.
1325 * Don't attempt if the target doesn't support REPORT LUNS.
1326 */
1327 if (bflags & BLIST_NOREPORTLUN)
1328 return 1;
1329 if (starget->scsi_level < SCSI_2 &&
1330 starget->scsi_level != SCSI_UNKNOWN)
1331 return 1;
1332 if (starget->scsi_level < SCSI_3 &&
1333 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1334 return 1;
1335 if (bflags & BLIST_NOLUN)
1336 return 0;
1337 if (starget->no_report_luns)
1338 return 1;
1339
1340 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1341 sdev = scsi_alloc_sdev(starget, 0, NULL);
1342 if (!sdev)
1343 return 0;
1344 if (scsi_device_get(sdev)) {
1345 __scsi_remove_device(sdev);
1346 return 0;
1347 }
1348 }
1349
1350 /*
1351 * Allocate enough to hold the header (the same size as one scsi_lun)
1352 * plus the number of luns we are requesting. 511 was the default
1353 * value of the now removed max_report_luns parameter.
1354 */
1355 length = (511 + 1) * sizeof(struct scsi_lun);
1356 retry:
1357 lun_data = kmalloc(length, GFP_KERNEL);
1358 if (!lun_data) {
1359 printk(ALLOC_FAILURE_MSG, __func__);
1360 goto out;
1361 }
1362
1363 scsi_cmd[0] = REPORT_LUNS;
1364
1365 /*
1366 * bytes 1 - 5: reserved, set to zero.
1367 */
1368 memset(&scsi_cmd[1], 0, 5);
1369
1370 /*
1371 * bytes 6 - 9: length of the command.
1372 */
1373 put_unaligned_be32(length, &scsi_cmd[6]);
1374
1375 scsi_cmd[10] = 0; /* reserved */
1376 scsi_cmd[11] = 0; /* control */
1377
1378 /*
1379 * We can get a UNIT ATTENTION, for example a power on/reset, so
1380 * retry a few times (like sd.c does for TEST UNIT READY).
1381 * Experience shows some combinations of adapter/devices get at
1382 * least two power on/resets.
1383 *
1384 * Illegal requests (for devices that do not support REPORT LUNS)
1385 * should come through as a check condition, and will not generate
1386 * a retry.
1387 */
1388 for (retries = 0; retries < 3; retries++) {
1389 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1390 "scsi scan: Sending REPORT LUNS to (try %d)\n",
1391 retries));
1392
1393 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1394 lun_data, length, &sshdr,
1395 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL);
1396
1397 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1398 "scsi scan: REPORT LUNS"
1399 " %s (try %d) result 0x%x\n",
1400 result ? "failed" : "successful",
1401 retries, result));
1402 if (result == 0)
1403 break;
1404 else if (scsi_sense_valid(&sshdr)) {
1405 if (sshdr.sense_key != UNIT_ATTENTION)
1406 break;
1407 }
1408 }
1409
1410 if (result) {
1411 /*
1412 * The device probably does not support a REPORT LUN command
1413 */
1414 ret = 1;
1415 goto out_err;
1416 }
1417
1418 /*
1419 * Get the length from the first four bytes of lun_data.
1420 */
1421 if (get_unaligned_be32(lun_data->scsi_lun) +
1422 sizeof(struct scsi_lun) > length) {
1423 length = get_unaligned_be32(lun_data->scsi_lun) +
1424 sizeof(struct scsi_lun);
1425 kfree(lun_data);
1426 goto retry;
1427 }
1428 length = get_unaligned_be32(lun_data->scsi_lun);
1429
1430 num_luns = (length / sizeof(struct scsi_lun));
1431
1432 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1433 "scsi scan: REPORT LUN scan\n"));
1434
1435 /*
1436 * Scan the luns in lun_data. The entry at offset 0 is really
1437 * the header, so start at 1 and go up to and including num_luns.
1438 */
1439 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1440 lun = scsilun_to_int(lunp);
1441
1442 if (lun > sdev->host->max_lun) {
1443 sdev_printk(KERN_WARNING, sdev,
1444 "lun%llu has a LUN larger than"
1445 " allowed by the host adapter\n", lun);
1446 } else {
1447 int res;
1448
1449 res = scsi_probe_and_add_lun(starget,
1450 lun, NULL, NULL, rescan, NULL);
1451 if (res == SCSI_SCAN_NO_RESPONSE) {
1452 /*
1453 * Got some results, but now none, abort.
1454 */
1455 sdev_printk(KERN_ERR, sdev,
1456 "Unexpected response"
1457 " from lun %llu while scanning, scan"
1458 " aborted\n", (unsigned long long)lun);
1459 break;
1460 }
1461 }
1462 }
1463
1464 out_err:
1465 kfree(lun_data);
1466 out:
1467 if (scsi_device_created(sdev))
1468 /*
1469 * the sdev we used didn't appear in the report luns scan
1470 */
1471 __scsi_remove_device(sdev);
1472 scsi_device_put(sdev);
1473 return ret;
1474 }
1475
__scsi_add_device(struct Scsi_Host * shost,uint channel,uint id,u64 lun,void * hostdata)1476 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1477 uint id, u64 lun, void *hostdata)
1478 {
1479 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1480 struct device *parent = &shost->shost_gendev;
1481 struct scsi_target *starget;
1482
1483 if (strncmp(scsi_scan_type, "none", 4) == 0)
1484 return ERR_PTR(-ENODEV);
1485
1486 starget = scsi_alloc_target(parent, channel, id);
1487 if (!starget)
1488 return ERR_PTR(-ENOMEM);
1489 scsi_autopm_get_target(starget);
1490
1491 mutex_lock(&shost->scan_mutex);
1492 if (!shost->async_scan)
1493 scsi_complete_async_scans();
1494
1495 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1496 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1497 scsi_autopm_put_host(shost);
1498 }
1499 mutex_unlock(&shost->scan_mutex);
1500 scsi_autopm_put_target(starget);
1501 /*
1502 * paired with scsi_alloc_target(). Target will be destroyed unless
1503 * scsi_probe_and_add_lun made an underlying device visible
1504 */
1505 scsi_target_reap(starget);
1506 put_device(&starget->dev);
1507
1508 return sdev;
1509 }
1510 EXPORT_SYMBOL(__scsi_add_device);
1511
scsi_add_device(struct Scsi_Host * host,uint channel,uint target,u64 lun)1512 int scsi_add_device(struct Scsi_Host *host, uint channel,
1513 uint target, u64 lun)
1514 {
1515 struct scsi_device *sdev =
1516 __scsi_add_device(host, channel, target, lun, NULL);
1517 if (IS_ERR(sdev))
1518 return PTR_ERR(sdev);
1519
1520 scsi_device_put(sdev);
1521 return 0;
1522 }
1523 EXPORT_SYMBOL(scsi_add_device);
1524
scsi_rescan_device(struct device * dev)1525 void scsi_rescan_device(struct device *dev)
1526 {
1527 struct scsi_device *sdev = to_scsi_device(dev);
1528
1529 device_lock(dev);
1530
1531 scsi_attach_vpd(sdev);
1532
1533 if (sdev->handler && sdev->handler->rescan)
1534 sdev->handler->rescan(sdev);
1535
1536 if (dev->driver && try_module_get(dev->driver->owner)) {
1537 struct scsi_driver *drv = to_scsi_driver(dev->driver);
1538
1539 if (drv->rescan)
1540 drv->rescan(dev);
1541 module_put(dev->driver->owner);
1542 }
1543 device_unlock(dev);
1544 }
1545 EXPORT_SYMBOL(scsi_rescan_device);
1546
__scsi_scan_target(struct device * parent,unsigned int channel,unsigned int id,u64 lun,enum scsi_scan_mode rescan)1547 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1548 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1549 {
1550 struct Scsi_Host *shost = dev_to_shost(parent);
1551 blist_flags_t bflags = 0;
1552 int res;
1553 struct scsi_target *starget;
1554
1555 if (shost->this_id == id)
1556 /*
1557 * Don't scan the host adapter
1558 */
1559 return;
1560
1561 starget = scsi_alloc_target(parent, channel, id);
1562 if (!starget)
1563 return;
1564 scsi_autopm_get_target(starget);
1565
1566 if (lun != SCAN_WILD_CARD) {
1567 /*
1568 * Scan for a specific host/chan/id/lun.
1569 */
1570 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1571 goto out_reap;
1572 }
1573
1574 /*
1575 * Scan LUN 0, if there is some response, scan further. Ideally, we
1576 * would not configure LUN 0 until all LUNs are scanned.
1577 */
1578 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1579 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1580 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1581 /*
1582 * The REPORT LUN did not scan the target,
1583 * do a sequential scan.
1584 */
1585 scsi_sequential_lun_scan(starget, bflags,
1586 starget->scsi_level, rescan);
1587 }
1588
1589 out_reap:
1590 scsi_autopm_put_target(starget);
1591 /*
1592 * paired with scsi_alloc_target(): determine if the target has
1593 * any children at all and if not, nuke it
1594 */
1595 scsi_target_reap(starget);
1596
1597 put_device(&starget->dev);
1598 }
1599
1600 /**
1601 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1602 * @parent: host to scan
1603 * @channel: channel to scan
1604 * @id: target id to scan
1605 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1606 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for
1607 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
1608 * and SCSI_SCAN_MANUAL to force scanning even if
1609 * 'scan=manual' is set.
1610 *
1611 * Description:
1612 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1613 * and possibly all LUNs on the target id.
1614 *
1615 * First try a REPORT LUN scan, if that does not scan the target, do a
1616 * sequential scan of LUNs on the target id.
1617 **/
scsi_scan_target(struct device * parent,unsigned int channel,unsigned int id,u64 lun,enum scsi_scan_mode rescan)1618 void scsi_scan_target(struct device *parent, unsigned int channel,
1619 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1620 {
1621 struct Scsi_Host *shost = dev_to_shost(parent);
1622
1623 if (strncmp(scsi_scan_type, "none", 4) == 0)
1624 return;
1625
1626 if (rescan != SCSI_SCAN_MANUAL &&
1627 strncmp(scsi_scan_type, "manual", 6) == 0)
1628 return;
1629
1630 mutex_lock(&shost->scan_mutex);
1631 if (!shost->async_scan)
1632 scsi_complete_async_scans();
1633
1634 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1635 __scsi_scan_target(parent, channel, id, lun, rescan);
1636 scsi_autopm_put_host(shost);
1637 }
1638 mutex_unlock(&shost->scan_mutex);
1639 }
1640 EXPORT_SYMBOL(scsi_scan_target);
1641
scsi_scan_channel(struct Scsi_Host * shost,unsigned int channel,unsigned int id,u64 lun,enum scsi_scan_mode rescan)1642 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1643 unsigned int id, u64 lun,
1644 enum scsi_scan_mode rescan)
1645 {
1646 uint order_id;
1647
1648 if (id == SCAN_WILD_CARD)
1649 for (id = 0; id < shost->max_id; ++id) {
1650 /*
1651 * XXX adapter drivers when possible (FCP, iSCSI)
1652 * could modify max_id to match the current max,
1653 * not the absolute max.
1654 *
1655 * XXX add a shost id iterator, so for example,
1656 * the FC ID can be the same as a target id
1657 * without a huge overhead of sparse id's.
1658 */
1659 if (shost->reverse_ordering)
1660 /*
1661 * Scan from high to low id.
1662 */
1663 order_id = shost->max_id - id - 1;
1664 else
1665 order_id = id;
1666 __scsi_scan_target(&shost->shost_gendev, channel,
1667 order_id, lun, rescan);
1668 }
1669 else
1670 __scsi_scan_target(&shost->shost_gendev, channel,
1671 id, lun, rescan);
1672 }
1673
scsi_scan_host_selected(struct Scsi_Host * shost,unsigned int channel,unsigned int id,u64 lun,enum scsi_scan_mode rescan)1674 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1675 unsigned int id, u64 lun,
1676 enum scsi_scan_mode rescan)
1677 {
1678 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1679 "%s: <%u:%u:%llu>\n",
1680 __func__, channel, id, lun));
1681
1682 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1683 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1684 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))
1685 return -EINVAL;
1686
1687 mutex_lock(&shost->scan_mutex);
1688 if (!shost->async_scan)
1689 scsi_complete_async_scans();
1690
1691 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1692 if (channel == SCAN_WILD_CARD)
1693 for (channel = 0; channel <= shost->max_channel;
1694 channel++)
1695 scsi_scan_channel(shost, channel, id, lun,
1696 rescan);
1697 else
1698 scsi_scan_channel(shost, channel, id, lun, rescan);
1699 scsi_autopm_put_host(shost);
1700 }
1701 mutex_unlock(&shost->scan_mutex);
1702
1703 return 0;
1704 }
1705
scsi_sysfs_add_devices(struct Scsi_Host * shost)1706 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1707 {
1708 struct scsi_device *sdev;
1709 shost_for_each_device(sdev, shost) {
1710 /* target removed before the device could be added */
1711 if (sdev->sdev_state == SDEV_DEL)
1712 continue;
1713 /* If device is already visible, skip adding it to sysfs */
1714 if (sdev->is_visible)
1715 continue;
1716 if (!scsi_host_scan_allowed(shost) ||
1717 scsi_sysfs_add_sdev(sdev) != 0)
1718 __scsi_remove_device(sdev);
1719 }
1720 }
1721
1722 /**
1723 * scsi_prep_async_scan - prepare for an async scan
1724 * @shost: the host which will be scanned
1725 * Returns: a cookie to be passed to scsi_finish_async_scan()
1726 *
1727 * Tells the midlayer this host is going to do an asynchronous scan.
1728 * It reserves the host's position in the scanning list and ensures
1729 * that other asynchronous scans started after this one won't affect the
1730 * ordering of the discovered devices.
1731 */
scsi_prep_async_scan(struct Scsi_Host * shost)1732 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1733 {
1734 struct async_scan_data *data = NULL;
1735 unsigned long flags;
1736
1737 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1738 return NULL;
1739
1740 mutex_lock(&shost->scan_mutex);
1741 if (shost->async_scan) {
1742 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
1743 goto err;
1744 }
1745
1746 data = kmalloc(sizeof(*data), GFP_KERNEL);
1747 if (!data)
1748 goto err;
1749 data->shost = scsi_host_get(shost);
1750 if (!data->shost)
1751 goto err;
1752 init_completion(&data->prev_finished);
1753
1754 spin_lock_irqsave(shost->host_lock, flags);
1755 shost->async_scan = 1;
1756 spin_unlock_irqrestore(shost->host_lock, flags);
1757 mutex_unlock(&shost->scan_mutex);
1758
1759 spin_lock(&async_scan_lock);
1760 if (list_empty(&scanning_hosts))
1761 complete(&data->prev_finished);
1762 list_add_tail(&data->list, &scanning_hosts);
1763 spin_unlock(&async_scan_lock);
1764
1765 return data;
1766
1767 err:
1768 mutex_unlock(&shost->scan_mutex);
1769 kfree(data);
1770 return NULL;
1771 }
1772
1773 /**
1774 * scsi_finish_async_scan - asynchronous scan has finished
1775 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1776 *
1777 * All the devices currently attached to this host have been found.
1778 * This function announces all the devices it has found to the rest
1779 * of the system.
1780 */
scsi_finish_async_scan(struct async_scan_data * data)1781 static void scsi_finish_async_scan(struct async_scan_data *data)
1782 {
1783 struct Scsi_Host *shost;
1784 unsigned long flags;
1785
1786 if (!data)
1787 return;
1788
1789 shost = data->shost;
1790
1791 mutex_lock(&shost->scan_mutex);
1792
1793 if (!shost->async_scan) {
1794 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1795 dump_stack();
1796 mutex_unlock(&shost->scan_mutex);
1797 return;
1798 }
1799
1800 wait_for_completion(&data->prev_finished);
1801
1802 scsi_sysfs_add_devices(shost);
1803
1804 spin_lock_irqsave(shost->host_lock, flags);
1805 shost->async_scan = 0;
1806 spin_unlock_irqrestore(shost->host_lock, flags);
1807
1808 mutex_unlock(&shost->scan_mutex);
1809
1810 spin_lock(&async_scan_lock);
1811 list_del(&data->list);
1812 if (!list_empty(&scanning_hosts)) {
1813 struct async_scan_data *next = list_entry(scanning_hosts.next,
1814 struct async_scan_data, list);
1815 complete(&next->prev_finished);
1816 }
1817 spin_unlock(&async_scan_lock);
1818
1819 scsi_autopm_put_host(shost);
1820 scsi_host_put(shost);
1821 kfree(data);
1822 }
1823
do_scsi_scan_host(struct Scsi_Host * shost)1824 static void do_scsi_scan_host(struct Scsi_Host *shost)
1825 {
1826 if (shost->hostt->scan_finished) {
1827 unsigned long start = jiffies;
1828 if (shost->hostt->scan_start)
1829 shost->hostt->scan_start(shost);
1830
1831 while (!shost->hostt->scan_finished(shost, jiffies - start))
1832 msleep(10);
1833 } else {
1834 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1835 SCAN_WILD_CARD, 0);
1836 }
1837 }
1838
do_scan_async(void * _data,async_cookie_t c)1839 static void do_scan_async(void *_data, async_cookie_t c)
1840 {
1841 struct async_scan_data *data = _data;
1842 struct Scsi_Host *shost = data->shost;
1843
1844 do_scsi_scan_host(shost);
1845 scsi_finish_async_scan(data);
1846 }
1847
1848 /**
1849 * scsi_scan_host - scan the given adapter
1850 * @shost: adapter to scan
1851 **/
scsi_scan_host(struct Scsi_Host * shost)1852 void scsi_scan_host(struct Scsi_Host *shost)
1853 {
1854 struct async_scan_data *data;
1855
1856 if (strncmp(scsi_scan_type, "none", 4) == 0 ||
1857 strncmp(scsi_scan_type, "manual", 6) == 0)
1858 return;
1859 if (scsi_autopm_get_host(shost) < 0)
1860 return;
1861
1862 data = scsi_prep_async_scan(shost);
1863 if (!data) {
1864 do_scsi_scan_host(shost);
1865 scsi_autopm_put_host(shost);
1866 return;
1867 }
1868
1869 /* register with the async subsystem so wait_for_device_probe()
1870 * will flush this work
1871 */
1872 async_schedule(do_scan_async, data);
1873
1874 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1875 }
1876 EXPORT_SYMBOL(scsi_scan_host);
1877
scsi_forget_host(struct Scsi_Host * shost)1878 void scsi_forget_host(struct Scsi_Host *shost)
1879 {
1880 struct scsi_device *sdev;
1881 unsigned long flags;
1882
1883 restart:
1884 spin_lock_irqsave(shost->host_lock, flags);
1885 list_for_each_entry(sdev, &shost->__devices, siblings) {
1886 if (sdev->sdev_state == SDEV_DEL)
1887 continue;
1888 spin_unlock_irqrestore(shost->host_lock, flags);
1889 __scsi_remove_device(sdev);
1890 goto restart;
1891 }
1892 spin_unlock_irqrestore(shost->host_lock, flags);
1893 }
1894
1895 /**
1896 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
1897 * @shost: Host that needs a scsi_device
1898 *
1899 * Lock status: None assumed.
1900 *
1901 * Returns: The scsi_device or NULL
1902 *
1903 * Notes:
1904 * Attach a single scsi_device to the Scsi_Host - this should
1905 * be made to look like a "pseudo-device" that points to the
1906 * HA itself.
1907 *
1908 * Note - this device is not accessible from any high-level
1909 * drivers (including generics), which is probably not
1910 * optimal. We can add hooks later to attach.
1911 */
scsi_get_host_dev(struct Scsi_Host * shost)1912 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1913 {
1914 struct scsi_device *sdev = NULL;
1915 struct scsi_target *starget;
1916
1917 mutex_lock(&shost->scan_mutex);
1918 if (!scsi_host_scan_allowed(shost))
1919 goto out;
1920 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1921 if (!starget)
1922 goto out;
1923
1924 sdev = scsi_alloc_sdev(starget, 0, NULL);
1925 if (sdev)
1926 sdev->borken = 0;
1927 else
1928 scsi_target_reap(starget);
1929 put_device(&starget->dev);
1930 out:
1931 mutex_unlock(&shost->scan_mutex);
1932 return sdev;
1933 }
1934 EXPORT_SYMBOL(scsi_get_host_dev);
1935
1936 /**
1937 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
1938 * @sdev: Host device to be freed
1939 *
1940 * Lock status: None assumed.
1941 *
1942 * Returns: Nothing
1943 */
scsi_free_host_dev(struct scsi_device * sdev)1944 void scsi_free_host_dev(struct scsi_device *sdev)
1945 {
1946 BUG_ON(sdev->id != sdev->host->this_id);
1947
1948 __scsi_remove_device(sdev);
1949 }
1950 EXPORT_SYMBOL(scsi_free_host_dev);
1951
1952