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