1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 2000 Eric Youngdale,
6 * Copyright (C) 2002 Patrick Mansfield
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.
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.
15 * For every id of every channel on the given host:
17 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
18 * device or storage attached to LUN 0):
20 * If LUN 0 has a device attached, allocate and setup a
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.
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>
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>
50 #include "scsi_priv.h"
51 #include "scsi_logging.h"
53 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
54 " SCSI scanning, some SCSI devices might not be configured\n"
59 #define SCSI_TIMEOUT (2*HZ)
60 #define SCSI_REPORT_LUNS_TIMEOUT (30*HZ)
63 * Prefix values for the SCSI id's (stored in sysfs name field)
65 #define SCSI_UID_SER_NUM 'S'
66 #define SCSI_UID_UNKNOWN 'Z'
69 * Return values of some of the scanning functions.
71 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
72 * includes allocation or general failures preventing IO from being sent.
74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
80 #define SCSI_SCAN_NO_RESPONSE 0
81 #define SCSI_SCAN_TARGET_PRESENT 1
82 #define SCSI_SCAN_LUN_PRESENT 2
84 static const char *scsi_null_device_strs = "nullnullnullnull";
86 #define MAX_SCSI_LUNS 512
88 static u64 max_scsi_luns = MAX_SCSI_LUNS;
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)");
94 #ifdef CONFIG_SCSI_SCAN_ASYNC
95 #define SCSI_SCAN_TYPE_DEFAULT "async"
97 #define SCSI_SCAN_TYPE_DEFAULT "sync"
100 char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT;
102 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type),
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.");
108 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
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.");
115 /* This lock protects only this list */
116 static DEFINE_SPINLOCK(async_scan_lock);
117 static LIST_HEAD(scanning_hosts);
119 struct async_scan_data {
120 struct list_head list;
121 struct Scsi_Host *shost;
122 struct completion prev_finished;
126 * scsi_complete_async_scans - Wait for asynchronous scans to complete
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
133 int scsi_complete_async_scans(void)
135 struct async_scan_data *data;
138 if (list_empty(&scanning_hosts))
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.
144 data = kmalloc(sizeof(*data), GFP_KERNEL);
150 init_completion(&data->prev_finished);
152 spin_lock(&async_scan_lock);
153 /* Check that there's still somebody else on the list */
154 if (list_empty(&scanning_hosts))
156 list_add_tail(&data->list, &scanning_hosts);
157 spin_unlock(&async_scan_lock);
159 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
160 wait_for_completion(&data->prev_finished);
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);
170 spin_unlock(&async_scan_lock);
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
182 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
183 * Called for BLIST_KEY devices.
185 static void scsi_unlock_floptical(struct scsi_device *sdev,
186 unsigned char *result)
188 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
190 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
191 scsi_cmd[0] = MODE_SENSE;
195 scsi_cmd[4] = 0x2a; /* size */
197 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
198 SCSI_TIMEOUT, 3, NULL);
202 * scsi_alloc_sdev - allocate and setup a scsi_Device
203 * @starget: which target to allocate a &scsi_device for
205 * @hostdata: usually NULL and set by ->slave_alloc instead
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.
213 * scsi_Device pointer, or NULL on failure.
215 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
216 u64 lun, void *hostdata)
219 struct scsi_device *sdev;
220 struct request_queue *q;
221 int display_failure_msg = 1, ret;
222 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
224 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
229 sdev->vendor = scsi_null_device_strs;
230 sdev->model = scsi_null_device_strs;
231 sdev->rev = scsi_null_device_strs;
233 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
234 sdev->id = starget->id;
236 sdev->channel = starget->channel;
237 mutex_init(&sdev->state_mutex);
238 sdev->sdev_state = SDEV_CREATED;
239 INIT_LIST_HEAD(&sdev->siblings);
240 INIT_LIST_HEAD(&sdev->same_target_siblings);
241 INIT_LIST_HEAD(&sdev->starved_entry);
242 INIT_LIST_HEAD(&sdev->event_list);
243 spin_lock_init(&sdev->list_lock);
244 mutex_init(&sdev->inquiry_mutex);
245 INIT_WORK(&sdev->event_work, scsi_evt_thread);
246 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
248 sdev->sdev_gendev.parent = get_device(&starget->dev);
249 sdev->sdev_target = starget;
251 /* usually NULL and set by ->slave_alloc instead */
252 sdev->hostdata = hostdata;
254 /* if the device needs this changing, it may do so in the
255 * slave_configure function */
256 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
259 * Some low level driver could use device->type
264 * Assume that the device will have handshaking problems,
265 * and then fix this field later if it turns out it
270 q = blk_mq_init_queue(&sdev->host->tag_set);
272 /* release fn is set up in scsi_sysfs_device_initialise, so
273 * have to free and put manually here */
274 put_device(&starget->dev);
278 sdev->request_queue = q;
280 __scsi_init_queue(sdev->host, q);
281 blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
282 WARN_ON_ONCE(!blk_get_queue(q));
284 depth = sdev->host->cmd_per_lun ?: 1;
287 * Use .can_queue as budget map's depth because we have to
288 * support adjusting queue depth from sysfs. Meantime use
289 * default device queue depth to figure out sbitmap shift
290 * since we use this queue depth most of times.
292 if (sbitmap_init_node(&sdev->budget_map,
293 scsi_device_max_queue_depth(sdev),
294 sbitmap_calculate_shift(depth),
295 GFP_KERNEL, sdev->request_queue->node,
297 put_device(&starget->dev);
302 scsi_change_queue_depth(sdev, depth);
304 scsi_sysfs_device_initialize(sdev);
306 if (shost->hostt->slave_alloc) {
307 ret = shost->hostt->slave_alloc(sdev);
310 * if LLDD reports slave not present, don't clutter
311 * console with alloc failure messages
314 display_failure_msg = 0;
315 goto out_device_destroy;
322 __scsi_remove_device(sdev);
324 if (display_failure_msg)
325 printk(ALLOC_FAILURE_MSG, __func__);
329 static void scsi_target_destroy(struct scsi_target *starget)
331 struct device *dev = &starget->dev;
332 struct Scsi_Host *shost = dev_to_shost(dev->parent);
335 BUG_ON(starget->state == STARGET_DEL);
336 starget->state = STARGET_DEL;
337 transport_destroy_device(dev);
338 spin_lock_irqsave(shost->host_lock, flags);
339 if (shost->hostt->target_destroy)
340 shost->hostt->target_destroy(starget);
341 list_del_init(&starget->siblings);
342 spin_unlock_irqrestore(shost->host_lock, flags);
346 static void scsi_target_dev_release(struct device *dev)
348 struct device *parent = dev->parent;
349 struct scsi_target *starget = to_scsi_target(dev);
355 static struct device_type scsi_target_type = {
356 .name = "scsi_target",
357 .release = scsi_target_dev_release,
360 int scsi_is_target_device(const struct device *dev)
362 return dev->type == &scsi_target_type;
364 EXPORT_SYMBOL(scsi_is_target_device);
366 static struct scsi_target *__scsi_find_target(struct device *parent,
367 int channel, uint id)
369 struct scsi_target *starget, *found_starget = NULL;
370 struct Scsi_Host *shost = dev_to_shost(parent);
372 * Search for an existing target for this sdev.
374 list_for_each_entry(starget, &shost->__targets, siblings) {
375 if (starget->id == id &&
376 starget->channel == channel) {
377 found_starget = starget;
382 get_device(&found_starget->dev);
384 return found_starget;
388 * scsi_target_reap_ref_release - remove target from visibility
389 * @kref: the reap_ref in the target being released
391 * Called on last put of reap_ref, which is the indication that no device
392 * under this target is visible anymore, so render the target invisible in
393 * sysfs. Note: we have to be in user context here because the target reaps
394 * should be done in places where the scsi device visibility is being removed.
396 static void scsi_target_reap_ref_release(struct kref *kref)
398 struct scsi_target *starget
399 = container_of(kref, struct scsi_target, reap_ref);
402 * if we get here and the target is still in a CREATED state that
403 * means it was allocated but never made visible (because a scan
404 * turned up no LUNs), so don't call device_del() on it.
406 if ((starget->state != STARGET_CREATED) &&
407 (starget->state != STARGET_CREATED_REMOVE)) {
408 transport_remove_device(&starget->dev);
409 device_del(&starget->dev);
411 scsi_target_destroy(starget);
414 static void scsi_target_reap_ref_put(struct scsi_target *starget)
416 kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
420 * scsi_alloc_target - allocate a new or find an existing target
421 * @parent: parent of the target (need not be a scsi host)
422 * @channel: target channel number (zero if no channels)
423 * @id: target id number
425 * Return an existing target if one exists, provided it hasn't already
426 * gone into STARGET_DEL state, otherwise allocate a new target.
428 * The target is returned with an incremented reference, so the caller
429 * is responsible for both reaping and doing a last put
431 static struct scsi_target *scsi_alloc_target(struct device *parent,
432 int channel, uint id)
434 struct Scsi_Host *shost = dev_to_shost(parent);
435 struct device *dev = NULL;
437 const int size = sizeof(struct scsi_target)
438 + shost->transportt->target_size;
439 struct scsi_target *starget;
440 struct scsi_target *found_target;
443 starget = kzalloc(size, GFP_KERNEL);
445 printk(KERN_ERR "%s: allocation failure\n", __func__);
449 device_initialize(dev);
450 kref_init(&starget->reap_ref);
451 dev->parent = get_device(parent);
452 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
453 dev->bus = &scsi_bus_type;
454 dev->type = &scsi_target_type;
456 starget->channel = channel;
457 starget->can_queue = 0;
458 INIT_LIST_HEAD(&starget->siblings);
459 INIT_LIST_HEAD(&starget->devices);
460 starget->state = STARGET_CREATED;
461 starget->scsi_level = SCSI_2;
462 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
464 spin_lock_irqsave(shost->host_lock, flags);
466 found_target = __scsi_find_target(parent, channel, id);
470 list_add_tail(&starget->siblings, &shost->__targets);
471 spin_unlock_irqrestore(shost->host_lock, flags);
472 /* allocate and add */
473 transport_setup_device(dev);
474 if (shost->hostt->target_alloc) {
475 error = shost->hostt->target_alloc(starget);
479 dev_err(dev, "target allocation failed, error %d\n", error);
480 /* don't want scsi_target_reap to do the final
481 * put because it will be under the host lock */
482 scsi_target_destroy(starget);
492 * release routine already fired if kref is zero, so if we can still
493 * take the reference, the target must be alive. If we can't, it must
494 * be dying and we need to wait for a new target
496 ref_got = kref_get_unless_zero(&found_target->reap_ref);
498 spin_unlock_irqrestore(shost->host_lock, flags);
504 * Unfortunately, we found a dying target; need to wait until it's
505 * dead before we can get a new one. There is an anomaly here. We
506 * *should* call scsi_target_reap() to balance the kref_get() of the
507 * reap_ref above. However, since the target being released, it's
508 * already invisible and the reap_ref is irrelevant. If we call
509 * scsi_target_reap() we might spuriously do another device_del() on
510 * an already invisible target.
512 put_device(&found_target->dev);
514 * length of time is irrelevant here, we just want to yield the CPU
515 * for a tick to avoid busy waiting for the target to die.
522 * scsi_target_reap - check to see if target is in use and destroy if not
523 * @starget: target to be checked
525 * This is used after removing a LUN or doing a last put of the target
526 * it checks atomically that nothing is using the target and removes
529 void scsi_target_reap(struct scsi_target *starget)
532 * serious problem if this triggers: STARGET_DEL is only set in the if
533 * the reap_ref drops to zero, so we're trying to do another final put
534 * on an already released kref
536 BUG_ON(starget->state == STARGET_DEL);
537 scsi_target_reap_ref_put(starget);
541 * scsi_sanitize_inquiry_string - remove non-graphical chars from an
542 * INQUIRY result string
543 * @s: INQUIRY result string to sanitize
544 * @len: length of the string
547 * The SCSI spec says that INQUIRY vendor, product, and revision
548 * strings must consist entirely of graphic ASCII characters,
549 * padded on the right with spaces. Since not all devices obey
550 * this rule, we will replace non-graphic or non-ASCII characters
551 * with spaces. Exception: a NUL character is interpreted as a
552 * string terminator, so all the following characters are set to
555 void scsi_sanitize_inquiry_string(unsigned char *s, int len)
559 for (; len > 0; (--len, ++s)) {
562 if (terminated || *s < 0x20 || *s > 0x7e)
566 EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
569 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
570 * @sdev: scsi_device to probe
571 * @inq_result: area to store the INQUIRY result
572 * @result_len: len of inq_result
573 * @bflags: store any bflags found here
576 * Probe the lun associated with @req using a standard SCSI INQUIRY;
578 * If the INQUIRY is successful, zero is returned and the
579 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
580 * are copied to the scsi_device any flags value is stored in *@bflags.
582 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
583 int result_len, blist_flags_t *bflags)
585 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
586 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
587 int response_len = 0;
588 int pass, count, result;
589 struct scsi_sense_hdr sshdr;
593 /* Perform up to 3 passes. The first pass uses a conservative
594 * transfer length of 36 unless sdev->inquiry_len specifies a
595 * different value. */
596 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
597 try_inquiry_len = first_inquiry_len;
601 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
602 "scsi scan: INQUIRY pass %d length %d\n",
603 pass, try_inquiry_len));
605 /* Each pass gets up to three chances to ignore Unit Attention */
606 for (count = 0; count < 3; ++count) {
609 memset(scsi_cmd, 0, 6);
610 scsi_cmd[0] = INQUIRY;
611 scsi_cmd[4] = (unsigned char) try_inquiry_len;
613 memset(inq_result, 0, try_inquiry_len);
615 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
616 inq_result, try_inquiry_len, &sshdr,
617 HZ / 2 + HZ * scsi_inq_timeout, 3,
620 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
621 "scsi scan: INQUIRY %s with code 0x%x\n",
622 result ? "failed" : "successful", result));
626 * not-ready to ready transition [asc/ascq=0x28/0x0]
627 * or power-on, reset [asc/ascq=0x29/0x0], continue.
628 * INQUIRY should not yield UNIT_ATTENTION
629 * but many buggy devices do so anyway.
631 if (scsi_status_is_check_condition(result) &&
632 scsi_sense_valid(&sshdr)) {
633 if ((sshdr.sense_key == UNIT_ATTENTION) &&
634 ((sshdr.asc == 0x28) ||
635 (sshdr.asc == 0x29)) &&
639 } else if (result == 0) {
641 * if nothing was transferred, we try
642 * again. It's a workaround for some USB
645 if (resid == try_inquiry_len)
652 scsi_sanitize_inquiry_string(&inq_result[8], 8);
653 scsi_sanitize_inquiry_string(&inq_result[16], 16);
654 scsi_sanitize_inquiry_string(&inq_result[32], 4);
656 response_len = inq_result[4] + 5;
657 if (response_len > 255)
658 response_len = first_inquiry_len; /* sanity */
661 * Get any flags for this device.
663 * XXX add a bflags to scsi_device, and replace the
664 * corresponding bit fields in scsi_device, so bflags
665 * need not be passed as an argument.
667 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
670 /* When the first pass succeeds we gain information about
671 * what larger transfer lengths might work. */
673 if (BLIST_INQUIRY_36 & *bflags)
674 next_inquiry_len = 36;
675 else if (sdev->inquiry_len)
676 next_inquiry_len = sdev->inquiry_len;
678 next_inquiry_len = response_len;
680 /* If more data is available perform the second pass */
681 if (next_inquiry_len > try_inquiry_len) {
682 try_inquiry_len = next_inquiry_len;
688 } else if (pass == 2) {
689 sdev_printk(KERN_INFO, sdev,
690 "scsi scan: %d byte inquiry failed. "
691 "Consider BLIST_INQUIRY_36 for this device\n",
694 /* If this pass failed, the third pass goes back and transfers
695 * the same amount as we successfully got in the first pass. */
696 try_inquiry_len = first_inquiry_len;
701 /* If the last transfer attempt got an error, assume the
702 * peripheral doesn't exist or is dead. */
706 /* Don't report any more data than the device says is valid */
707 sdev->inquiry_len = min(try_inquiry_len, response_len);
710 * XXX Abort if the response length is less than 36? If less than
711 * 32, the lookup of the device flags (above) could be invalid,
712 * and it would be possible to take an incorrect action - we do
713 * not want to hang because of a short INQUIRY. On the flip side,
714 * if the device is spun down or becoming ready (and so it gives a
715 * short INQUIRY), an abort here prevents any further use of the
716 * device, including spin up.
718 * On the whole, the best approach seems to be to assume the first
719 * 36 bytes are valid no matter what the device says. That's
720 * better than copying < 36 bytes to the inquiry-result buffer
721 * and displaying garbage for the Vendor, Product, or Revision
724 if (sdev->inquiry_len < 36) {
725 if (!sdev->host->short_inquiry) {
726 shost_printk(KERN_INFO, sdev->host,
727 "scsi scan: INQUIRY result too short (%d),"
728 " using 36\n", sdev->inquiry_len);
729 sdev->host->short_inquiry = 1;
731 sdev->inquiry_len = 36;
735 * Related to the above issue:
737 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
738 * and if not ready, sent a START_STOP to start (maybe spin up) and
739 * then send the INQUIRY again, since the INQUIRY can change after
740 * a device is initialized.
742 * Ideally, start a device if explicitly asked to do so. This
743 * assumes that a device is spun up on power on, spun down on
744 * request, and then spun up on request.
748 * The scanning code needs to know the scsi_level, even if no
749 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
750 * non-zero LUNs can be scanned.
752 sdev->scsi_level = inq_result[2] & 0x07;
753 if (sdev->scsi_level >= 2 ||
754 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
756 sdev->sdev_target->scsi_level = sdev->scsi_level;
759 * If SCSI-2 or lower, and if the transport requires it,
760 * store the LUN value in CDB[1].
762 sdev->lun_in_cdb = 0;
763 if (sdev->scsi_level <= SCSI_2 &&
764 sdev->scsi_level != SCSI_UNKNOWN &&
765 !sdev->host->no_scsi2_lun_in_cdb)
766 sdev->lun_in_cdb = 1;
772 * scsi_add_lun - allocate and fully initialze a scsi_device
773 * @sdev: holds information to be stored in the new scsi_device
774 * @inq_result: holds the result of a previous INQUIRY to the LUN
775 * @bflags: black/white list flag
776 * @async: 1 if this device is being scanned asynchronously
779 * Initialize the scsi_device @sdev. Optionally set fields based
780 * on values in *@bflags.
783 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
784 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
786 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
787 blist_flags_t *bflags, int async)
792 * XXX do not save the inquiry, since it can change underneath us,
793 * save just vendor/model/rev.
795 * Rather than save it and have an ioctl that retrieves the saved
796 * value, have an ioctl that executes the same INQUIRY code used
797 * in scsi_probe_lun, let user level programs doing INQUIRY
798 * scanning run at their own risk, or supply a user level program
799 * that can correctly scan.
803 * Copy at least 36 bytes of INQUIRY data, so that we don't
804 * dereference unallocated memory when accessing the Vendor,
805 * Product, and Revision strings. Badly behaved devices may set
806 * the INQUIRY Additional Length byte to a small value, indicating
807 * these strings are invalid, but often they contain plausible data
808 * nonetheless. It doesn't matter if the device sent < 36 bytes
809 * total, since scsi_probe_lun() initializes inq_result with 0s.
811 sdev->inquiry = kmemdup(inq_result,
812 max_t(size_t, sdev->inquiry_len, 36),
814 if (sdev->inquiry == NULL)
815 return SCSI_SCAN_NO_RESPONSE;
817 sdev->vendor = (char *) (sdev->inquiry + 8);
818 sdev->model = (char *) (sdev->inquiry + 16);
819 sdev->rev = (char *) (sdev->inquiry + 32);
821 if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
823 * sata emulation layer device. This is a hack to work around
824 * the SATL power management specifications which state that
825 * when the SATL detects the device has gone into standby
826 * mode, it shall respond with NOT READY.
828 sdev->allow_restart = 1;
831 if (*bflags & BLIST_ISROM) {
832 sdev->type = TYPE_ROM;
835 sdev->type = (inq_result[0] & 0x1f);
836 sdev->removable = (inq_result[1] & 0x80) >> 7;
839 * some devices may respond with wrong type for
840 * well-known logical units. Force well-known type
841 * to enumerate them correctly.
843 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
844 sdev_printk(KERN_WARNING, sdev,
845 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
846 __func__, sdev->type, (unsigned int)sdev->lun);
847 sdev->type = TYPE_WLUN;
852 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
853 /* RBC and MMC devices can return SCSI-3 compliance and yet
854 * still not support REPORT LUNS, so make them act as
855 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
856 * specifically set */
857 if ((*bflags & BLIST_REPORTLUN2) == 0)
858 *bflags |= BLIST_NOREPORTLUN;
862 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
863 * spec says: The device server is capable of supporting the
864 * specified peripheral device type on this logical unit. However,
865 * the physical device is not currently connected to this logical
868 * The above is vague, as it implies that we could treat 001 and
869 * 011 the same. Stay compatible with previous code, and create a
870 * scsi_device for a PQ of 1
872 * Don't set the device offline here; rather let the upper
873 * level drivers eval the PQ to decide whether they should
874 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
877 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
878 sdev->lockable = sdev->removable;
879 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
881 if (sdev->scsi_level >= SCSI_3 ||
882 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
884 if (inq_result[7] & 0x60)
886 if (inq_result[7] & 0x10)
889 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
890 "ANSI: %d%s\n", scsi_device_type(sdev->type),
891 sdev->vendor, sdev->model, sdev->rev,
892 sdev->inq_periph_qual, inq_result[2] & 0x07,
893 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
895 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
896 !(*bflags & BLIST_NOTQ)) {
897 sdev->tagged_supported = 1;
898 sdev->simple_tags = 1;
902 * Some devices (Texel CD ROM drives) have handshaking problems
903 * when used with the Seagate controllers. borken is initialized
904 * to 1, and then set it to 0 here.
906 if ((*bflags & BLIST_BORKEN) == 0)
909 if (*bflags & BLIST_NO_ULD_ATTACH)
910 sdev->no_uld_attach = 1;
913 * Apparently some really broken devices (contrary to the SCSI
914 * standards) need to be selected without asserting ATN
916 if (*bflags & BLIST_SELECT_NO_ATN)
917 sdev->select_no_atn = 1;
920 * Maximum 512 sector transfer length
921 * broken RA4x00 Compaq Disk Array
923 if (*bflags & BLIST_MAX_512)
924 blk_queue_max_hw_sectors(sdev->request_queue, 512);
926 * Max 1024 sector transfer length for targets that report incorrect
927 * max/optimal lengths and relied on the old block layer safe default
929 else if (*bflags & BLIST_MAX_1024)
930 blk_queue_max_hw_sectors(sdev->request_queue, 1024);
933 * Some devices may not want to have a start command automatically
934 * issued when a device is added.
936 if (*bflags & BLIST_NOSTARTONADD)
937 sdev->no_start_on_add = 1;
939 if (*bflags & BLIST_SINGLELUN)
940 scsi_target(sdev)->single_lun = 1;
942 sdev->use_10_for_rw = 1;
944 /* some devices don't like REPORT SUPPORTED OPERATION CODES
945 * and will simply timeout causing sd_mod init to take a very
947 if (*bflags & BLIST_NO_RSOC)
948 sdev->no_report_opcodes = 1;
950 /* set the device running here so that slave configure
952 mutex_lock(&sdev->state_mutex);
953 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
955 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
956 mutex_unlock(&sdev->state_mutex);
959 sdev_printk(KERN_ERR, sdev,
960 "in wrong state %s to complete scan\n",
961 scsi_device_state_name(sdev->sdev_state));
962 return SCSI_SCAN_NO_RESPONSE;
965 if (*bflags & BLIST_NOT_LOCKABLE)
968 if (*bflags & BLIST_RETRY_HWERROR)
969 sdev->retry_hwerror = 1;
971 if (*bflags & BLIST_NO_DIF)
974 if (*bflags & BLIST_UNMAP_LIMIT_WS)
975 sdev->unmap_limit_for_ws = 1;
977 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
979 if (*bflags & BLIST_TRY_VPD_PAGES)
980 sdev->try_vpd_pages = 1;
981 else if (*bflags & BLIST_SKIP_VPD_PAGES)
982 sdev->skip_vpd_pages = 1;
984 transport_configure_device(&sdev->sdev_gendev);
986 if (sdev->host->hostt->slave_configure) {
987 ret = sdev->host->hostt->slave_configure(sdev);
990 * if LLDD reports slave not present, don't clutter
991 * console with alloc failure messages
994 sdev_printk(KERN_ERR, sdev,
995 "failed to configure device\n");
997 return SCSI_SCAN_NO_RESPONSE;
1001 if (sdev->scsi_level >= SCSI_3)
1002 scsi_attach_vpd(sdev);
1004 sdev->max_queue_depth = sdev->queue_depth;
1005 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth);
1006 sdev->sdev_bflags = *bflags;
1009 * Ok, the device is now all set up, we can
1010 * register it and tell the rest of the kernel
1013 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
1014 return SCSI_SCAN_NO_RESPONSE;
1016 return SCSI_SCAN_LUN_PRESENT;
1019 #ifdef CONFIG_SCSI_LOGGING
1021 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
1022 * @buf: Output buffer with at least end-first+1 bytes of space
1023 * @inq: Inquiry buffer (input)
1024 * @first: Offset of string into inq
1025 * @end: Index after last character in inq
1027 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
1028 unsigned first, unsigned end)
1030 unsigned term = 0, idx;
1032 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1033 if (inq[idx+first] > ' ') {
1034 buf[idx] = inq[idx+first];
1046 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1047 * @starget: pointer to target device structure
1048 * @lun: LUN of target device
1049 * @bflagsp: store bflags here if not NULL
1050 * @sdevp: probe the LUN corresponding to this scsi_device
1051 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only
1052 * needed on first scan
1053 * @hostdata: passed to scsi_alloc_sdev()
1056 * Call scsi_probe_lun, if a LUN with an attached device is found,
1057 * allocate and set it up by calling scsi_add_lun.
1061 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1062 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1063 * attached at the LUN
1064 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1066 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1067 u64 lun, blist_flags_t *bflagsp,
1068 struct scsi_device **sdevp,
1069 enum scsi_scan_mode rescan,
1072 struct scsi_device *sdev;
1073 unsigned char *result;
1074 blist_flags_t bflags;
1075 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1076 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1079 * The rescan flag is used as an optimization, the first scan of a
1080 * host adapter calls into here with rescan == 0.
1082 sdev = scsi_device_lookup_by_target(starget, lun);
1084 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) {
1085 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1086 "scsi scan: device exists on %s\n",
1087 dev_name(&sdev->sdev_gendev)));
1091 scsi_device_put(sdev);
1094 *bflagsp = scsi_get_device_flags(sdev,
1097 return SCSI_SCAN_LUN_PRESENT;
1099 scsi_device_put(sdev);
1101 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1105 result = kmalloc(result_len, GFP_KERNEL);
1109 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1110 goto out_free_result;
1115 * result contains valid SCSI INQUIRY data.
1117 if ((result[0] >> 5) == 3) {
1119 * For a Peripheral qualifier 3 (011b), the SCSI
1120 * spec says: The device server is not capable of
1121 * supporting a physical device on this logical
1124 * For disks, this implies that there is no
1125 * logical disk configured at sdev->lun, but there
1126 * is a target id responding.
1128 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1129 " peripheral qualifier of 3, device not"
1132 SCSI_LOG_SCAN_BUS(1, {
1133 unsigned char vend[9];
1134 unsigned char mod[17];
1136 sdev_printk(KERN_INFO, sdev,
1137 "scsi scan: consider passing scsi_mod."
1138 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1139 scsi_inq_str(vend, result, 8, 16),
1140 scsi_inq_str(mod, result, 16, 32));
1145 res = SCSI_SCAN_TARGET_PRESENT;
1146 goto out_free_result;
1150 * Some targets may set slight variations of PQ and PDT to signal
1151 * that no LUN is present, so don't add sdev in these cases.
1152 * Two specific examples are:
1153 * 1) NetApp targets: return PQ=1, PDT=0x1f
1154 * 2) IBM/2145 targets: return PQ=1, PDT=0
1155 * 3) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1156 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1159 * 1) SCSI SPC-3, pp. 145-146
1160 * PQ=1: "A peripheral device having the specified peripheral
1161 * device type is not connected to this logical unit. However, the
1162 * device server is capable of supporting the specified peripheral
1163 * device type on this logical unit."
1164 * PDT=0x1f: "Unknown or no device type"
1165 * 2) USB UFI 1.0, p. 20
1166 * PDT=00h Direct-access device (floppy)
1167 * PDT=1Fh none (no FDD connected to the requested logical unit)
1169 if (((result[0] >> 5) == 1 ||
1170 (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f)) &&
1171 !scsi_is_wlun(lun)) {
1172 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1173 "scsi scan: peripheral device type"
1174 " of 31, no device added\n"));
1175 res = SCSI_SCAN_TARGET_PRESENT;
1176 goto out_free_result;
1179 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1180 if (res == SCSI_SCAN_LUN_PRESENT) {
1181 if (bflags & BLIST_KEY) {
1183 scsi_unlock_floptical(sdev, result);
1190 if (res == SCSI_SCAN_LUN_PRESENT) {
1192 if (scsi_device_get(sdev) == 0) {
1195 __scsi_remove_device(sdev);
1196 res = SCSI_SCAN_NO_RESPONSE;
1200 __scsi_remove_device(sdev);
1206 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1207 * @starget: pointer to target structure to scan
1208 * @bflags: black/white list flag for LUN 0
1209 * @scsi_level: Which version of the standard does this device adhere to
1210 * @rescan: passed to scsi_probe_add_lun()
1213 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1214 * scanned) to some maximum lun until a LUN is found with no device
1215 * attached. Use the bflags to figure out any oddities.
1217 * Modifies sdevscan->lun.
1219 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1220 blist_flags_t bflags, int scsi_level,
1221 enum scsi_scan_mode rescan)
1224 u64 sparse_lun, lun;
1225 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1227 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
1228 "scsi scan: Sequential scan\n"));
1230 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1232 * If this device is known to support sparse multiple units,
1233 * override the other settings, and scan all of them. Normally,
1234 * SCSI-3 devices should be scanned via the REPORT LUNS.
1236 if (bflags & BLIST_SPARSELUN) {
1237 max_dev_lun = shost->max_lun;
1243 * If less than SCSI_1_CCS, and no special lun scanning, stop
1244 * scanning; this matches 2.4 behaviour, but could just be a bug
1245 * (to continue scanning a SCSI_1_CCS device).
1247 * This test is broken. We might not have any device on lun0 for
1248 * a sparselun device, and if that's the case then how would we
1249 * know the real scsi_level, eh? It might make sense to just not
1250 * scan any SCSI_1 device for non-0 luns, but that check would best
1251 * go into scsi_alloc_sdev() and just have it return null when asked
1252 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1254 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1255 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1260 * If this device is known to support multiple units, override
1261 * the other settings, and scan all of them.
1263 if (bflags & BLIST_FORCELUN)
1264 max_dev_lun = shost->max_lun;
1266 * REGAL CDC-4X: avoid hang after LUN 4
1268 if (bflags & BLIST_MAX5LUN)
1269 max_dev_lun = min(5U, max_dev_lun);
1271 * Do not scan SCSI-2 or lower device past LUN 7, unless
1274 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1275 max_dev_lun = min(8U, max_dev_lun);
1277 max_dev_lun = min(256U, max_dev_lun);
1280 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1281 * until we reach the max, or no LUN is found and we are not
1284 for (lun = 1; lun < max_dev_lun; ++lun)
1285 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1286 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1292 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1293 * @starget: which target
1294 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1295 * @rescan: nonzero if we can skip code only needed on first scan
1298 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1299 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1301 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1302 * LUNs even if it's older than SCSI-3.
1303 * If BLIST_NOREPORTLUN is set, return 1 always.
1304 * If BLIST_NOLUN is set, return 0 always.
1305 * If starget->no_report_luns is set, return 1 always.
1308 * 0: scan completed (or no memory, so further scanning is futile)
1309 * 1: could not scan with REPORT LUN
1311 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags,
1312 enum scsi_scan_mode rescan)
1314 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1315 unsigned int length;
1317 unsigned int num_luns;
1318 unsigned int retries;
1320 struct scsi_lun *lunp, *lun_data;
1321 struct scsi_sense_hdr sshdr;
1322 struct scsi_device *sdev;
1323 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1327 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1328 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1329 * support more than 8 LUNs.
1330 * Don't attempt if the target doesn't support REPORT LUNS.
1332 if (bflags & BLIST_NOREPORTLUN)
1334 if (starget->scsi_level < SCSI_2 &&
1335 starget->scsi_level != SCSI_UNKNOWN)
1337 if (starget->scsi_level < SCSI_3 &&
1338 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1340 if (bflags & BLIST_NOLUN)
1342 if (starget->no_report_luns)
1345 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1346 sdev = scsi_alloc_sdev(starget, 0, NULL);
1349 if (scsi_device_get(sdev)) {
1350 __scsi_remove_device(sdev);
1356 * Allocate enough to hold the header (the same size as one scsi_lun)
1357 * plus the number of luns we are requesting. 511 was the default
1358 * value of the now removed max_report_luns parameter.
1360 length = (511 + 1) * sizeof(struct scsi_lun);
1362 lun_data = kmalloc(length, GFP_KERNEL);
1364 printk(ALLOC_FAILURE_MSG, __func__);
1368 scsi_cmd[0] = REPORT_LUNS;
1371 * bytes 1 - 5: reserved, set to zero.
1373 memset(&scsi_cmd[1], 0, 5);
1376 * bytes 6 - 9: length of the command.
1378 put_unaligned_be32(length, &scsi_cmd[6]);
1380 scsi_cmd[10] = 0; /* reserved */
1381 scsi_cmd[11] = 0; /* control */
1384 * We can get a UNIT ATTENTION, for example a power on/reset, so
1385 * retry a few times (like sd.c does for TEST UNIT READY).
1386 * Experience shows some combinations of adapter/devices get at
1387 * least two power on/resets.
1389 * Illegal requests (for devices that do not support REPORT LUNS)
1390 * should come through as a check condition, and will not generate
1393 for (retries = 0; retries < 3; retries++) {
1394 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1395 "scsi scan: Sending REPORT LUNS to (try %d)\n",
1398 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1399 lun_data, length, &sshdr,
1400 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL);
1402 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1403 "scsi scan: REPORT LUNS"
1404 " %s (try %d) result 0x%x\n",
1405 result ? "failed" : "successful",
1409 else if (scsi_sense_valid(&sshdr)) {
1410 if (sshdr.sense_key != UNIT_ATTENTION)
1417 * The device probably does not support a REPORT LUN command
1424 * Get the length from the first four bytes of lun_data.
1426 if (get_unaligned_be32(lun_data->scsi_lun) +
1427 sizeof(struct scsi_lun) > length) {
1428 length = get_unaligned_be32(lun_data->scsi_lun) +
1429 sizeof(struct scsi_lun);
1433 length = get_unaligned_be32(lun_data->scsi_lun);
1435 num_luns = (length / sizeof(struct scsi_lun));
1437 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1438 "scsi scan: REPORT LUN scan\n"));
1441 * Scan the luns in lun_data. The entry at offset 0 is really
1442 * the header, so start at 1 and go up to and including num_luns.
1444 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1445 lun = scsilun_to_int(lunp);
1447 if (lun > sdev->host->max_lun) {
1448 sdev_printk(KERN_WARNING, sdev,
1449 "lun%llu has a LUN larger than"
1450 " allowed by the host adapter\n", lun);
1454 res = scsi_probe_and_add_lun(starget,
1455 lun, NULL, NULL, rescan, NULL);
1456 if (res == SCSI_SCAN_NO_RESPONSE) {
1458 * Got some results, but now none, abort.
1460 sdev_printk(KERN_ERR, sdev,
1461 "Unexpected response"
1462 " from lun %llu while scanning, scan"
1463 " aborted\n", (unsigned long long)lun);
1472 if (scsi_device_created(sdev))
1474 * the sdev we used didn't appear in the report luns scan
1476 __scsi_remove_device(sdev);
1477 scsi_device_put(sdev);
1481 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1482 uint id, u64 lun, void *hostdata)
1484 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1485 struct device *parent = &shost->shost_gendev;
1486 struct scsi_target *starget;
1488 if (strncmp(scsi_scan_type, "none", 4) == 0)
1489 return ERR_PTR(-ENODEV);
1491 starget = scsi_alloc_target(parent, channel, id);
1493 return ERR_PTR(-ENOMEM);
1494 scsi_autopm_get_target(starget);
1496 mutex_lock(&shost->scan_mutex);
1497 if (!shost->async_scan)
1498 scsi_complete_async_scans();
1500 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1501 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1502 scsi_autopm_put_host(shost);
1504 mutex_unlock(&shost->scan_mutex);
1505 scsi_autopm_put_target(starget);
1507 * paired with scsi_alloc_target(). Target will be destroyed unless
1508 * scsi_probe_and_add_lun made an underlying device visible
1510 scsi_target_reap(starget);
1511 put_device(&starget->dev);
1515 EXPORT_SYMBOL(__scsi_add_device);
1517 int scsi_add_device(struct Scsi_Host *host, uint channel,
1518 uint target, u64 lun)
1520 struct scsi_device *sdev =
1521 __scsi_add_device(host, channel, target, lun, NULL);
1523 return PTR_ERR(sdev);
1525 scsi_device_put(sdev);
1528 EXPORT_SYMBOL(scsi_add_device);
1530 void scsi_rescan_device(struct device *dev)
1532 struct scsi_device *sdev = to_scsi_device(dev);
1536 scsi_attach_vpd(sdev);
1538 if (sdev->handler && sdev->handler->rescan)
1539 sdev->handler->rescan(sdev);
1541 if (dev->driver && try_module_get(dev->driver->owner)) {
1542 struct scsi_driver *drv = to_scsi_driver(dev->driver);
1546 module_put(dev->driver->owner);
1550 EXPORT_SYMBOL(scsi_rescan_device);
1552 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1553 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1555 struct Scsi_Host *shost = dev_to_shost(parent);
1556 blist_flags_t bflags = 0;
1558 struct scsi_target *starget;
1560 if (shost->this_id == id)
1562 * Don't scan the host adapter
1566 starget = scsi_alloc_target(parent, channel, id);
1569 scsi_autopm_get_target(starget);
1571 if (lun != SCAN_WILD_CARD) {
1573 * Scan for a specific host/chan/id/lun.
1575 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1580 * Scan LUN 0, if there is some response, scan further. Ideally, we
1581 * would not configure LUN 0 until all LUNs are scanned.
1583 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1584 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1585 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1587 * The REPORT LUN did not scan the target,
1588 * do a sequential scan.
1590 scsi_sequential_lun_scan(starget, bflags,
1591 starget->scsi_level, rescan);
1595 scsi_autopm_put_target(starget);
1597 * paired with scsi_alloc_target(): determine if the target has
1598 * any children at all and if not, nuke it
1600 scsi_target_reap(starget);
1602 put_device(&starget->dev);
1606 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1607 * @parent: host to scan
1608 * @channel: channel to scan
1609 * @id: target id to scan
1610 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1611 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for
1612 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
1613 * and SCSI_SCAN_MANUAL to force scanning even if
1614 * 'scan=manual' is set.
1617 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1618 * and possibly all LUNs on the target id.
1620 * First try a REPORT LUN scan, if that does not scan the target, do a
1621 * sequential scan of LUNs on the target id.
1623 void scsi_scan_target(struct device *parent, unsigned int channel,
1624 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1626 struct Scsi_Host *shost = dev_to_shost(parent);
1628 if (strncmp(scsi_scan_type, "none", 4) == 0)
1631 if (rescan != SCSI_SCAN_MANUAL &&
1632 strncmp(scsi_scan_type, "manual", 6) == 0)
1635 mutex_lock(&shost->scan_mutex);
1636 if (!shost->async_scan)
1637 scsi_complete_async_scans();
1639 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1640 __scsi_scan_target(parent, channel, id, lun, rescan);
1641 scsi_autopm_put_host(shost);
1643 mutex_unlock(&shost->scan_mutex);
1645 EXPORT_SYMBOL(scsi_scan_target);
1647 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1648 unsigned int id, u64 lun,
1649 enum scsi_scan_mode rescan)
1653 if (id == SCAN_WILD_CARD)
1654 for (id = 0; id < shost->max_id; ++id) {
1656 * XXX adapter drivers when possible (FCP, iSCSI)
1657 * could modify max_id to match the current max,
1658 * not the absolute max.
1660 * XXX add a shost id iterator, so for example,
1661 * the FC ID can be the same as a target id
1662 * without a huge overhead of sparse id's.
1664 if (shost->reverse_ordering)
1666 * Scan from high to low id.
1668 order_id = shost->max_id - id - 1;
1671 __scsi_scan_target(&shost->shost_gendev, channel,
1672 order_id, lun, rescan);
1675 __scsi_scan_target(&shost->shost_gendev, channel,
1679 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1680 unsigned int id, u64 lun,
1681 enum scsi_scan_mode rescan)
1683 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1684 "%s: <%u:%u:%llu>\n",
1685 __func__, channel, id, lun));
1687 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1688 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1689 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))
1692 mutex_lock(&shost->scan_mutex);
1693 if (!shost->async_scan)
1694 scsi_complete_async_scans();
1696 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1697 if (channel == SCAN_WILD_CARD)
1698 for (channel = 0; channel <= shost->max_channel;
1700 scsi_scan_channel(shost, channel, id, lun,
1703 scsi_scan_channel(shost, channel, id, lun, rescan);
1704 scsi_autopm_put_host(shost);
1706 mutex_unlock(&shost->scan_mutex);
1711 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1713 struct scsi_device *sdev;
1714 shost_for_each_device(sdev, shost) {
1715 /* target removed before the device could be added */
1716 if (sdev->sdev_state == SDEV_DEL)
1718 /* If device is already visible, skip adding it to sysfs */
1719 if (sdev->is_visible)
1721 if (!scsi_host_scan_allowed(shost) ||
1722 scsi_sysfs_add_sdev(sdev) != 0)
1723 __scsi_remove_device(sdev);
1728 * scsi_prep_async_scan - prepare for an async scan
1729 * @shost: the host which will be scanned
1730 * Returns: a cookie to be passed to scsi_finish_async_scan()
1732 * Tells the midlayer this host is going to do an asynchronous scan.
1733 * It reserves the host's position in the scanning list and ensures
1734 * that other asynchronous scans started after this one won't affect the
1735 * ordering of the discovered devices.
1737 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1739 struct async_scan_data *data = NULL;
1740 unsigned long flags;
1742 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1745 mutex_lock(&shost->scan_mutex);
1746 if (shost->async_scan) {
1747 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
1751 data = kmalloc(sizeof(*data), GFP_KERNEL);
1754 data->shost = scsi_host_get(shost);
1757 init_completion(&data->prev_finished);
1759 spin_lock_irqsave(shost->host_lock, flags);
1760 shost->async_scan = 1;
1761 spin_unlock_irqrestore(shost->host_lock, flags);
1762 mutex_unlock(&shost->scan_mutex);
1764 spin_lock(&async_scan_lock);
1765 if (list_empty(&scanning_hosts))
1766 complete(&data->prev_finished);
1767 list_add_tail(&data->list, &scanning_hosts);
1768 spin_unlock(&async_scan_lock);
1773 mutex_unlock(&shost->scan_mutex);
1779 * scsi_finish_async_scan - asynchronous scan has finished
1780 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1782 * All the devices currently attached to this host have been found.
1783 * This function announces all the devices it has found to the rest
1786 static void scsi_finish_async_scan(struct async_scan_data *data)
1788 struct Scsi_Host *shost;
1789 unsigned long flags;
1794 shost = data->shost;
1796 mutex_lock(&shost->scan_mutex);
1798 if (!shost->async_scan) {
1799 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1801 mutex_unlock(&shost->scan_mutex);
1805 wait_for_completion(&data->prev_finished);
1807 scsi_sysfs_add_devices(shost);
1809 spin_lock_irqsave(shost->host_lock, flags);
1810 shost->async_scan = 0;
1811 spin_unlock_irqrestore(shost->host_lock, flags);
1813 mutex_unlock(&shost->scan_mutex);
1815 spin_lock(&async_scan_lock);
1816 list_del(&data->list);
1817 if (!list_empty(&scanning_hosts)) {
1818 struct async_scan_data *next = list_entry(scanning_hosts.next,
1819 struct async_scan_data, list);
1820 complete(&next->prev_finished);
1822 spin_unlock(&async_scan_lock);
1824 scsi_autopm_put_host(shost);
1825 scsi_host_put(shost);
1829 static void do_scsi_scan_host(struct Scsi_Host *shost)
1831 if (shost->hostt->scan_finished) {
1832 unsigned long start = jiffies;
1833 if (shost->hostt->scan_start)
1834 shost->hostt->scan_start(shost);
1836 while (!shost->hostt->scan_finished(shost, jiffies - start))
1839 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1844 static void do_scan_async(void *_data, async_cookie_t c)
1846 struct async_scan_data *data = _data;
1847 struct Scsi_Host *shost = data->shost;
1849 do_scsi_scan_host(shost);
1850 scsi_finish_async_scan(data);
1854 * scsi_scan_host - scan the given adapter
1855 * @shost: adapter to scan
1857 void scsi_scan_host(struct Scsi_Host *shost)
1859 struct async_scan_data *data;
1861 if (strncmp(scsi_scan_type, "none", 4) == 0 ||
1862 strncmp(scsi_scan_type, "manual", 6) == 0)
1864 if (scsi_autopm_get_host(shost) < 0)
1867 data = scsi_prep_async_scan(shost);
1869 do_scsi_scan_host(shost);
1870 scsi_autopm_put_host(shost);
1874 /* register with the async subsystem so wait_for_device_probe()
1875 * will flush this work
1877 async_schedule(do_scan_async, data);
1879 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1881 EXPORT_SYMBOL(scsi_scan_host);
1883 void scsi_forget_host(struct Scsi_Host *shost)
1885 struct scsi_device *sdev;
1886 unsigned long flags;
1889 spin_lock_irqsave(shost->host_lock, flags);
1890 list_for_each_entry(sdev, &shost->__devices, siblings) {
1891 if (sdev->sdev_state == SDEV_DEL)
1893 spin_unlock_irqrestore(shost->host_lock, flags);
1894 __scsi_remove_device(sdev);
1897 spin_unlock_irqrestore(shost->host_lock, flags);
1901 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
1902 * @shost: Host that needs a scsi_device
1904 * Lock status: None assumed.
1906 * Returns: The scsi_device or NULL
1909 * Attach a single scsi_device to the Scsi_Host - this should
1910 * be made to look like a "pseudo-device" that points to the
1913 * Note - this device is not accessible from any high-level
1914 * drivers (including generics), which is probably not
1915 * optimal. We can add hooks later to attach.
1917 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1919 struct scsi_device *sdev = NULL;
1920 struct scsi_target *starget;
1922 mutex_lock(&shost->scan_mutex);
1923 if (!scsi_host_scan_allowed(shost))
1925 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1929 sdev = scsi_alloc_sdev(starget, 0, NULL);
1933 scsi_target_reap(starget);
1934 put_device(&starget->dev);
1936 mutex_unlock(&shost->scan_mutex);
1939 EXPORT_SYMBOL(scsi_get_host_dev);
1942 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
1943 * @sdev: Host device to be freed
1945 * Lock status: None assumed.
1949 void scsi_free_host_dev(struct scsi_device *sdev)
1951 BUG_ON(sdev->id != sdev->host->this_id);
1953 __scsi_remove_device(sdev);
1955 EXPORT_SYMBOL(scsi_free_host_dev);