4 * Copyright (C) 2000 Eric Youngdale,
5 * Copyright (C) 2002 Patrick Mansfield
7 * The general scanning/probing algorithm is as follows, exceptions are
8 * made to it depending on device specific flags, compilation options, and
9 * global variable (boot or module load time) settings.
11 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
12 * device attached, a scsi_device is allocated and setup for it.
14 * For every id of every channel on the given host:
16 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
17 * device or storage attached to LUN 0):
19 * If LUN 0 has a device attached, allocate and setup a
22 * If target is SCSI-3 or up, issue a REPORT LUN, and scan
23 * all of the LUNs returned by the REPORT LUN; else,
24 * sequentially scan LUNs up until some maximum is reached,
25 * or a LUN is seen that cannot have a device attached to it.
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/init.h>
31 #include <linux/blkdev.h>
32 #include <linux/delay.h>
33 #include <linux/kthread.h>
34 #include <linux/spinlock.h>
35 #include <linux/async.h>
36 #include <linux/slab.h>
38 #include <scsi/scsi.h>
39 #include <scsi/scsi_cmnd.h>
40 #include <scsi/scsi_device.h>
41 #include <scsi/scsi_driver.h>
42 #include <scsi/scsi_devinfo.h>
43 #include <scsi/scsi_host.h>
44 #include <scsi/scsi_transport.h>
45 #include <scsi/scsi_eh.h>
47 #include "scsi_priv.h"
48 #include "scsi_logging.h"
50 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
51 " SCSI scanning, some SCSI devices might not be configured\n"
56 #define SCSI_TIMEOUT (2*HZ)
59 * Prefix values for the SCSI id's (stored in sysfs name field)
61 #define SCSI_UID_SER_NUM 'S'
62 #define SCSI_UID_UNKNOWN 'Z'
65 * Return values of some of the scanning functions.
67 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
68 * includes allocation or general failures preventing IO from being sent.
70 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
73 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
76 #define SCSI_SCAN_NO_RESPONSE 0
77 #define SCSI_SCAN_TARGET_PRESENT 1
78 #define SCSI_SCAN_LUN_PRESENT 2
80 static const char *scsi_null_device_strs = "nullnullnullnull";
82 #define MAX_SCSI_LUNS 512
84 static u64 max_scsi_luns = MAX_SCSI_LUNS;
86 module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);
87 MODULE_PARM_DESC(max_luns,
88 "last scsi LUN (should be between 1 and 2^64-1)");
90 #ifdef CONFIG_SCSI_SCAN_ASYNC
91 #define SCSI_SCAN_TYPE_DEFAULT "async"
93 #define SCSI_SCAN_TYPE_DEFAULT "sync"
96 char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT;
98 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO);
99 MODULE_PARM_DESC(scan, "sync, async or none");
102 * max_scsi_report_luns: the maximum number of LUNS that will be
103 * returned from the REPORT LUNS command. 8 times this value must
104 * be allocated. In theory this could be up to an 8 byte value, but
105 * in practice, the maximum number of LUNs suppored by any device
108 static unsigned int max_scsi_report_luns = 511;
110 module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR);
111 MODULE_PARM_DESC(max_report_luns,
112 "REPORT LUNS maximum number of LUNS received (should be"
113 " between 1 and 16384)");
115 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
117 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
118 MODULE_PARM_DESC(inq_timeout,
119 "Timeout (in seconds) waiting for devices to answer INQUIRY."
120 " Default is 20. Some devices may need more; most need less.");
122 /* This lock protects only this list */
123 static DEFINE_SPINLOCK(async_scan_lock);
124 static LIST_HEAD(scanning_hosts);
126 struct async_scan_data {
127 struct list_head list;
128 struct Scsi_Host *shost;
129 struct completion prev_finished;
133 * scsi_complete_async_scans - Wait for asynchronous scans to complete
135 * When this function returns, any host which started scanning before
136 * this function was called will have finished its scan. Hosts which
137 * started scanning after this function was called may or may not have
140 int scsi_complete_async_scans(void)
142 struct async_scan_data *data;
145 if (list_empty(&scanning_hosts))
147 /* If we can't get memory immediately, that's OK. Just
148 * sleep a little. Even if we never get memory, the async
149 * scans will finish eventually.
151 data = kmalloc(sizeof(*data), GFP_KERNEL);
157 init_completion(&data->prev_finished);
159 spin_lock(&async_scan_lock);
160 /* Check that there's still somebody else on the list */
161 if (list_empty(&scanning_hosts))
163 list_add_tail(&data->list, &scanning_hosts);
164 spin_unlock(&async_scan_lock);
166 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
167 wait_for_completion(&data->prev_finished);
169 spin_lock(&async_scan_lock);
170 list_del(&data->list);
171 if (!list_empty(&scanning_hosts)) {
172 struct async_scan_data *next = list_entry(scanning_hosts.next,
173 struct async_scan_data, list);
174 complete(&next->prev_finished);
177 spin_unlock(&async_scan_lock);
184 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
185 * @sdev: scsi device to send command to
186 * @result: area to store the result of the MODE SENSE
189 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
190 * Called for BLIST_KEY devices.
192 static void scsi_unlock_floptical(struct scsi_device *sdev,
193 unsigned char *result)
195 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
197 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
198 scsi_cmd[0] = MODE_SENSE;
202 scsi_cmd[4] = 0x2a; /* size */
204 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
205 SCSI_TIMEOUT, 3, NULL);
209 * scsi_alloc_sdev - allocate and setup a scsi_Device
210 * @starget: which target to allocate a &scsi_device for
212 * @hostdata: usually NULL and set by ->slave_alloc instead
215 * Allocate, initialize for io, and return a pointer to a scsi_Device.
216 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
217 * adds scsi_Device to the appropriate list.
220 * scsi_Device pointer, or NULL on failure.
222 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
223 u64 lun, void *hostdata)
225 struct scsi_device *sdev;
226 int display_failure_msg = 1, ret;
227 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
228 extern void scsi_evt_thread(struct work_struct *work);
229 extern void scsi_requeue_run_queue(struct work_struct *work);
231 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
236 sdev->vendor = scsi_null_device_strs;
237 sdev->model = scsi_null_device_strs;
238 sdev->rev = scsi_null_device_strs;
240 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
241 sdev->id = starget->id;
243 sdev->channel = starget->channel;
244 sdev->sdev_state = SDEV_CREATED;
245 INIT_LIST_HEAD(&sdev->siblings);
246 INIT_LIST_HEAD(&sdev->same_target_siblings);
247 INIT_LIST_HEAD(&sdev->cmd_list);
248 INIT_LIST_HEAD(&sdev->starved_entry);
249 INIT_LIST_HEAD(&sdev->event_list);
250 spin_lock_init(&sdev->list_lock);
251 INIT_WORK(&sdev->event_work, scsi_evt_thread);
252 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
254 sdev->sdev_gendev.parent = get_device(&starget->dev);
255 sdev->sdev_target = starget;
257 /* usually NULL and set by ->slave_alloc instead */
258 sdev->hostdata = hostdata;
260 /* if the device needs this changing, it may do so in the
261 * slave_configure function */
262 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
265 * Some low level driver could use device->type
270 * Assume that the device will have handshaking problems,
271 * and then fix this field later if it turns out it
276 if (shost_use_blk_mq(shost))
277 sdev->request_queue = scsi_mq_alloc_queue(sdev);
279 sdev->request_queue = scsi_alloc_queue(sdev);
280 if (!sdev->request_queue) {
281 /* release fn is set up in scsi_sysfs_device_initialise, so
282 * have to free and put manually here */
283 put_device(&starget->dev);
287 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
288 sdev->request_queue->queuedata = sdev;
289 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
291 scsi_sysfs_device_initialize(sdev);
293 if (shost->hostt->slave_alloc) {
294 ret = shost->hostt->slave_alloc(sdev);
297 * if LLDD reports slave not present, don't clutter
298 * console with alloc failure messages
301 display_failure_msg = 0;
302 goto out_device_destroy;
309 __scsi_remove_device(sdev);
311 if (display_failure_msg)
312 printk(ALLOC_FAILURE_MSG, __func__);
316 static void scsi_target_destroy(struct scsi_target *starget)
318 struct device *dev = &starget->dev;
319 struct Scsi_Host *shost = dev_to_shost(dev->parent);
322 starget->state = STARGET_DEL;
323 transport_destroy_device(dev);
324 spin_lock_irqsave(shost->host_lock, flags);
325 if (shost->hostt->target_destroy)
326 shost->hostt->target_destroy(starget);
327 list_del_init(&starget->siblings);
328 spin_unlock_irqrestore(shost->host_lock, flags);
332 static void scsi_target_dev_release(struct device *dev)
334 struct device *parent = dev->parent;
335 struct scsi_target *starget = to_scsi_target(dev);
341 static struct device_type scsi_target_type = {
342 .name = "scsi_target",
343 .release = scsi_target_dev_release,
346 int scsi_is_target_device(const struct device *dev)
348 return dev->type == &scsi_target_type;
350 EXPORT_SYMBOL(scsi_is_target_device);
352 static struct scsi_target *__scsi_find_target(struct device *parent,
353 int channel, uint id)
355 struct scsi_target *starget, *found_starget = NULL;
356 struct Scsi_Host *shost = dev_to_shost(parent);
358 * Search for an existing target for this sdev.
360 list_for_each_entry(starget, &shost->__targets, siblings) {
361 if (starget->id == id &&
362 starget->channel == channel) {
363 found_starget = starget;
368 get_device(&found_starget->dev);
370 return found_starget;
374 * scsi_target_reap_ref_release - remove target from visibility
375 * @kref: the reap_ref in the target being released
377 * Called on last put of reap_ref, which is the indication that no device
378 * under this target is visible anymore, so render the target invisible in
379 * sysfs. Note: we have to be in user context here because the target reaps
380 * should be done in places where the scsi device visibility is being removed.
382 static void scsi_target_reap_ref_release(struct kref *kref)
384 struct scsi_target *starget
385 = container_of(kref, struct scsi_target, reap_ref);
388 * if we get here and the target is still in the CREATED state that
389 * means it was allocated but never made visible (because a scan
390 * turned up no LUNs), so don't call device_del() on it.
392 if (starget->state != STARGET_CREATED) {
393 transport_remove_device(&starget->dev);
394 device_del(&starget->dev);
396 scsi_target_destroy(starget);
399 static void scsi_target_reap_ref_put(struct scsi_target *starget)
401 kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
405 * scsi_alloc_target - allocate a new or find an existing target
406 * @parent: parent of the target (need not be a scsi host)
407 * @channel: target channel number (zero if no channels)
408 * @id: target id number
410 * Return an existing target if one exists, provided it hasn't already
411 * gone into STARGET_DEL state, otherwise allocate a new target.
413 * The target is returned with an incremented reference, so the caller
414 * is responsible for both reaping and doing a last put
416 static struct scsi_target *scsi_alloc_target(struct device *parent,
417 int channel, uint id)
419 struct Scsi_Host *shost = dev_to_shost(parent);
420 struct device *dev = NULL;
422 const int size = sizeof(struct scsi_target)
423 + shost->transportt->target_size;
424 struct scsi_target *starget;
425 struct scsi_target *found_target;
428 starget = kzalloc(size, GFP_KERNEL);
430 printk(KERN_ERR "%s: allocation failure\n", __func__);
434 device_initialize(dev);
435 kref_init(&starget->reap_ref);
436 dev->parent = get_device(parent);
437 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
438 dev->bus = &scsi_bus_type;
439 dev->type = &scsi_target_type;
441 starget->channel = channel;
442 starget->can_queue = 0;
443 INIT_LIST_HEAD(&starget->siblings);
444 INIT_LIST_HEAD(&starget->devices);
445 starget->state = STARGET_CREATED;
446 starget->scsi_level = SCSI_2;
447 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
449 spin_lock_irqsave(shost->host_lock, flags);
451 found_target = __scsi_find_target(parent, channel, id);
455 list_add_tail(&starget->siblings, &shost->__targets);
456 spin_unlock_irqrestore(shost->host_lock, flags);
457 /* allocate and add */
458 transport_setup_device(dev);
459 if (shost->hostt->target_alloc) {
460 error = shost->hostt->target_alloc(starget);
463 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
464 /* don't want scsi_target_reap to do the final
465 * put because it will be under the host lock */
466 scsi_target_destroy(starget);
476 * release routine already fired if kref is zero, so if we can still
477 * take the reference, the target must be alive. If we can't, it must
478 * be dying and we need to wait for a new target
480 ref_got = kref_get_unless_zero(&found_target->reap_ref);
482 spin_unlock_irqrestore(shost->host_lock, flags);
488 * Unfortunately, we found a dying target; need to wait until it's
489 * dead before we can get a new one. There is an anomaly here. We
490 * *should* call scsi_target_reap() to balance the kref_get() of the
491 * reap_ref above. However, since the target being released, it's
492 * already invisible and the reap_ref is irrelevant. If we call
493 * scsi_target_reap() we might spuriously do another device_del() on
494 * an already invisible target.
496 put_device(&found_target->dev);
498 * length of time is irrelevant here, we just want to yield the CPU
499 * for a tick to avoid busy waiting for the target to die.
506 * scsi_target_reap - check to see if target is in use and destroy if not
507 * @starget: target to be checked
509 * This is used after removing a LUN or doing a last put of the target
510 * it checks atomically that nothing is using the target and removes
513 void scsi_target_reap(struct scsi_target *starget)
516 * serious problem if this triggers: STARGET_DEL is only set in the if
517 * the reap_ref drops to zero, so we're trying to do another final put
518 * on an already released kref
520 BUG_ON(starget->state == STARGET_DEL);
521 scsi_target_reap_ref_put(starget);
525 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string
526 * @s: INQUIRY result string to sanitize
527 * @len: length of the string
530 * The SCSI spec says that INQUIRY vendor, product, and revision
531 * strings must consist entirely of graphic ASCII characters,
532 * padded on the right with spaces. Since not all devices obey
533 * this rule, we will replace non-graphic or non-ASCII characters
534 * with spaces. Exception: a NUL character is interpreted as a
535 * string terminator, so all the following characters are set to
538 static void sanitize_inquiry_string(unsigned char *s, int len)
542 for (; len > 0; (--len, ++s)) {
545 if (terminated || *s < 0x20 || *s > 0x7e)
551 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
552 * @sdev: scsi_device to probe
553 * @inq_result: area to store the INQUIRY result
554 * @result_len: len of inq_result
555 * @bflags: store any bflags found here
558 * Probe the lun associated with @req using a standard SCSI INQUIRY;
560 * If the INQUIRY is successful, zero is returned and the
561 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
562 * are copied to the scsi_device any flags value is stored in *@bflags.
564 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
565 int result_len, int *bflags)
567 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
568 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
569 int response_len = 0;
570 int pass, count, result;
571 struct scsi_sense_hdr sshdr;
575 /* Perform up to 3 passes. The first pass uses a conservative
576 * transfer length of 36 unless sdev->inquiry_len specifies a
577 * different value. */
578 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
579 try_inquiry_len = first_inquiry_len;
583 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
584 "scsi scan: INQUIRY pass %d length %d\n",
585 pass, try_inquiry_len));
587 /* Each pass gets up to three chances to ignore Unit Attention */
588 for (count = 0; count < 3; ++count) {
591 memset(scsi_cmd, 0, 6);
592 scsi_cmd[0] = INQUIRY;
593 scsi_cmd[4] = (unsigned char) try_inquiry_len;
595 memset(inq_result, 0, try_inquiry_len);
597 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
598 inq_result, try_inquiry_len, &sshdr,
599 HZ / 2 + HZ * scsi_inq_timeout, 3,
602 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
603 "scsi scan: INQUIRY %s with code 0x%x\n",
604 result ? "failed" : "successful", result));
608 * not-ready to ready transition [asc/ascq=0x28/0x0]
609 * or power-on, reset [asc/ascq=0x29/0x0], continue.
610 * INQUIRY should not yield UNIT_ATTENTION
611 * but many buggy devices do so anyway.
613 if ((driver_byte(result) & DRIVER_SENSE) &&
614 scsi_sense_valid(&sshdr)) {
615 if ((sshdr.sense_key == UNIT_ATTENTION) &&
616 ((sshdr.asc == 0x28) ||
617 (sshdr.asc == 0x29)) &&
623 * if nothing was transferred, we try
624 * again. It's a workaround for some USB
627 if (resid == try_inquiry_len)
634 sanitize_inquiry_string(&inq_result[8], 8);
635 sanitize_inquiry_string(&inq_result[16], 16);
636 sanitize_inquiry_string(&inq_result[32], 4);
638 response_len = inq_result[4] + 5;
639 if (response_len > 255)
640 response_len = first_inquiry_len; /* sanity */
643 * Get any flags for this device.
645 * XXX add a bflags to scsi_device, and replace the
646 * corresponding bit fields in scsi_device, so bflags
647 * need not be passed as an argument.
649 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
652 /* When the first pass succeeds we gain information about
653 * what larger transfer lengths might work. */
655 if (BLIST_INQUIRY_36 & *bflags)
656 next_inquiry_len = 36;
657 else if (BLIST_INQUIRY_58 & *bflags)
658 next_inquiry_len = 58;
659 else if (sdev->inquiry_len)
660 next_inquiry_len = sdev->inquiry_len;
662 next_inquiry_len = response_len;
664 /* If more data is available perform the second pass */
665 if (next_inquiry_len > try_inquiry_len) {
666 try_inquiry_len = next_inquiry_len;
672 } else if (pass == 2) {
673 sdev_printk(KERN_INFO, sdev,
674 "scsi scan: %d byte inquiry failed. "
675 "Consider BLIST_INQUIRY_36 for this device\n",
678 /* If this pass failed, the third pass goes back and transfers
679 * the same amount as we successfully got in the first pass. */
680 try_inquiry_len = first_inquiry_len;
685 /* If the last transfer attempt got an error, assume the
686 * peripheral doesn't exist or is dead. */
690 /* Don't report any more data than the device says is valid */
691 sdev->inquiry_len = min(try_inquiry_len, response_len);
694 * XXX Abort if the response length is less than 36? If less than
695 * 32, the lookup of the device flags (above) could be invalid,
696 * and it would be possible to take an incorrect action - we do
697 * not want to hang because of a short INQUIRY. On the flip side,
698 * if the device is spun down or becoming ready (and so it gives a
699 * short INQUIRY), an abort here prevents any further use of the
700 * device, including spin up.
702 * On the whole, the best approach seems to be to assume the first
703 * 36 bytes are valid no matter what the device says. That's
704 * better than copying < 36 bytes to the inquiry-result buffer
705 * and displaying garbage for the Vendor, Product, or Revision
708 if (sdev->inquiry_len < 36) {
709 sdev_printk(KERN_INFO, sdev,
710 "scsi scan: INQUIRY result too short (%d),"
711 " using 36\n", sdev->inquiry_len);
712 sdev->inquiry_len = 36;
716 * Related to the above issue:
718 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
719 * and if not ready, sent a START_STOP to start (maybe spin up) and
720 * then send the INQUIRY again, since the INQUIRY can change after
721 * a device is initialized.
723 * Ideally, start a device if explicitly asked to do so. This
724 * assumes that a device is spun up on power on, spun down on
725 * request, and then spun up on request.
729 * The scanning code needs to know the scsi_level, even if no
730 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
731 * non-zero LUNs can be scanned.
733 sdev->scsi_level = inq_result[2] & 0x07;
734 if (sdev->scsi_level >= 2 ||
735 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
737 sdev->sdev_target->scsi_level = sdev->scsi_level;
740 * If SCSI-2 or lower, and if the transport requires it,
741 * store the LUN value in CDB[1].
743 sdev->lun_in_cdb = 0;
744 if (sdev->scsi_level <= SCSI_2 &&
745 sdev->scsi_level != SCSI_UNKNOWN &&
746 !sdev->host->no_scsi2_lun_in_cdb)
747 sdev->lun_in_cdb = 1;
753 * scsi_add_lun - allocate and fully initialze a scsi_device
754 * @sdev: holds information to be stored in the new scsi_device
755 * @inq_result: holds the result of a previous INQUIRY to the LUN
756 * @bflags: black/white list flag
757 * @async: 1 if this device is being scanned asynchronously
760 * Initialize the scsi_device @sdev. Optionally set fields based
761 * on values in *@bflags.
764 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
765 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
767 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
768 int *bflags, int async)
773 * XXX do not save the inquiry, since it can change underneath us,
774 * save just vendor/model/rev.
776 * Rather than save it and have an ioctl that retrieves the saved
777 * value, have an ioctl that executes the same INQUIRY code used
778 * in scsi_probe_lun, let user level programs doing INQUIRY
779 * scanning run at their own risk, or supply a user level program
780 * that can correctly scan.
784 * Copy at least 36 bytes of INQUIRY data, so that we don't
785 * dereference unallocated memory when accessing the Vendor,
786 * Product, and Revision strings. Badly behaved devices may set
787 * the INQUIRY Additional Length byte to a small value, indicating
788 * these strings are invalid, but often they contain plausible data
789 * nonetheless. It doesn't matter if the device sent < 36 bytes
790 * total, since scsi_probe_lun() initializes inq_result with 0s.
792 sdev->inquiry = kmemdup(inq_result,
793 max_t(size_t, sdev->inquiry_len, 36),
795 if (sdev->inquiry == NULL)
796 return SCSI_SCAN_NO_RESPONSE;
798 sdev->vendor = (char *) (sdev->inquiry + 8);
799 sdev->model = (char *) (sdev->inquiry + 16);
800 sdev->rev = (char *) (sdev->inquiry + 32);
802 if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
804 * sata emulation layer device. This is a hack to work around
805 * the SATL power management specifications which state that
806 * when the SATL detects the device has gone into standby
807 * mode, it shall respond with NOT READY.
809 sdev->allow_restart = 1;
812 if (*bflags & BLIST_ISROM) {
813 sdev->type = TYPE_ROM;
816 sdev->type = (inq_result[0] & 0x1f);
817 sdev->removable = (inq_result[1] & 0x80) >> 7;
820 * some devices may respond with wrong type for
821 * well-known logical units. Force well-known type
822 * to enumerate them correctly.
824 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
825 sdev_printk(KERN_WARNING, sdev,
826 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
827 __func__, sdev->type, (unsigned int)sdev->lun);
828 sdev->type = TYPE_WLUN;
833 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
834 /* RBC and MMC devices can return SCSI-3 compliance and yet
835 * still not support REPORT LUNS, so make them act as
836 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
837 * specifically set */
838 if ((*bflags & BLIST_REPORTLUN2) == 0)
839 *bflags |= BLIST_NOREPORTLUN;
843 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
844 * spec says: The device server is capable of supporting the
845 * specified peripheral device type on this logical unit. However,
846 * the physical device is not currently connected to this logical
849 * The above is vague, as it implies that we could treat 001 and
850 * 011 the same. Stay compatible with previous code, and create a
851 * scsi_device for a PQ of 1
853 * Don't set the device offline here; rather let the upper
854 * level drivers eval the PQ to decide whether they should
855 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
858 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
859 sdev->lockable = sdev->removable;
860 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
862 if (sdev->scsi_level >= SCSI_3 ||
863 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
865 if (inq_result[7] & 0x60)
867 if (inq_result[7] & 0x10)
870 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
871 "ANSI: %d%s\n", scsi_device_type(sdev->type),
872 sdev->vendor, sdev->model, sdev->rev,
873 sdev->inq_periph_qual, inq_result[2] & 0x07,
874 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
876 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
877 !(*bflags & BLIST_NOTQ))
878 sdev->tagged_supported = 1;
881 * Some devices (Texel CD ROM drives) have handshaking problems
882 * when used with the Seagate controllers. borken is initialized
883 * to 1, and then set it to 0 here.
885 if ((*bflags & BLIST_BORKEN) == 0)
888 if (*bflags & BLIST_NO_ULD_ATTACH)
889 sdev->no_uld_attach = 1;
892 * Apparently some really broken devices (contrary to the SCSI
893 * standards) need to be selected without asserting ATN
895 if (*bflags & BLIST_SELECT_NO_ATN)
896 sdev->select_no_atn = 1;
899 * Maximum 512 sector transfer length
900 * broken RA4x00 Compaq Disk Array
902 if (*bflags & BLIST_MAX_512)
903 blk_queue_max_hw_sectors(sdev->request_queue, 512);
906 * Some devices may not want to have a start command automatically
907 * issued when a device is added.
909 if (*bflags & BLIST_NOSTARTONADD)
910 sdev->no_start_on_add = 1;
912 if (*bflags & BLIST_SINGLELUN)
913 scsi_target(sdev)->single_lun = 1;
915 sdev->use_10_for_rw = 1;
917 if (*bflags & BLIST_MS_SKIP_PAGE_08)
918 sdev->skip_ms_page_8 = 1;
920 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
921 sdev->skip_ms_page_3f = 1;
923 if (*bflags & BLIST_USE_10_BYTE_MS)
924 sdev->use_10_for_ms = 1;
926 /* some devices don't like REPORT SUPPORTED OPERATION CODES
927 * and will simply timeout causing sd_mod init to take a very
929 if (*bflags & BLIST_NO_RSOC)
930 sdev->no_report_opcodes = 1;
932 /* set the device running here so that slave configure
934 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
936 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
939 sdev_printk(KERN_ERR, sdev,
940 "in wrong state %s to complete scan\n",
941 scsi_device_state_name(sdev->sdev_state));
942 return SCSI_SCAN_NO_RESPONSE;
946 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
947 sdev->use_192_bytes_for_3f = 1;
949 if (*bflags & BLIST_NOT_LOCKABLE)
952 if (*bflags & BLIST_RETRY_HWERROR)
953 sdev->retry_hwerror = 1;
955 if (*bflags & BLIST_NO_DIF)
958 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
960 if (*bflags & BLIST_TRY_VPD_PAGES)
961 sdev->try_vpd_pages = 1;
962 else if (*bflags & BLIST_SKIP_VPD_PAGES)
963 sdev->skip_vpd_pages = 1;
965 transport_configure_device(&sdev->sdev_gendev);
967 if (sdev->host->hostt->slave_configure) {
968 ret = sdev->host->hostt->slave_configure(sdev);
971 * if LLDD reports slave not present, don't clutter
972 * console with alloc failure messages
975 sdev_printk(KERN_ERR, sdev,
976 "failed to configure device\n");
978 return SCSI_SCAN_NO_RESPONSE;
982 if (sdev->scsi_level >= SCSI_3)
983 scsi_attach_vpd(sdev);
985 sdev->max_queue_depth = sdev->queue_depth;
988 * Ok, the device is now all set up, we can
989 * register it and tell the rest of the kernel
992 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
993 return SCSI_SCAN_NO_RESPONSE;
995 return SCSI_SCAN_LUN_PRESENT;
998 #ifdef CONFIG_SCSI_LOGGING
1000 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
1001 * @buf: Output buffer with at least end-first+1 bytes of space
1002 * @inq: Inquiry buffer (input)
1003 * @first: Offset of string into inq
1004 * @end: Index after last character in inq
1006 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
1007 unsigned first, unsigned end)
1009 unsigned term = 0, idx;
1011 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1012 if (inq[idx+first] > ' ') {
1013 buf[idx] = inq[idx+first];
1025 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1026 * @starget: pointer to target device structure
1027 * @lun: LUN of target device
1028 * @bflagsp: store bflags here if not NULL
1029 * @sdevp: probe the LUN corresponding to this scsi_device
1030 * @rescan: if nonzero skip some code only needed on first scan
1031 * @hostdata: passed to scsi_alloc_sdev()
1034 * Call scsi_probe_lun, if a LUN with an attached device is found,
1035 * allocate and set it up by calling scsi_add_lun.
1038 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1039 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1040 * attached at the LUN
1041 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1043 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1044 u64 lun, int *bflagsp,
1045 struct scsi_device **sdevp, int rescan,
1048 struct scsi_device *sdev;
1049 unsigned char *result;
1050 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1051 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1054 * The rescan flag is used as an optimization, the first scan of a
1055 * host adapter calls into here with rescan == 0.
1057 sdev = scsi_device_lookup_by_target(starget, lun);
1059 if (rescan || !scsi_device_created(sdev)) {
1060 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1061 "scsi scan: device exists on %s\n",
1062 dev_name(&sdev->sdev_gendev)));
1066 scsi_device_put(sdev);
1069 *bflagsp = scsi_get_device_flags(sdev,
1072 return SCSI_SCAN_LUN_PRESENT;
1074 scsi_device_put(sdev);
1076 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1080 result = kmalloc(result_len, GFP_ATOMIC |
1081 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1085 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1086 goto out_free_result;
1091 * result contains valid SCSI INQUIRY data.
1093 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
1095 * For a Peripheral qualifier 3 (011b), the SCSI
1096 * spec says: The device server is not capable of
1097 * supporting a physical device on this logical
1100 * For disks, this implies that there is no
1101 * logical disk configured at sdev->lun, but there
1102 * is a target id responding.
1104 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1105 " peripheral qualifier of 3, device not"
1108 SCSI_LOG_SCAN_BUS(1, {
1109 unsigned char vend[9];
1110 unsigned char mod[17];
1112 sdev_printk(KERN_INFO, sdev,
1113 "scsi scan: consider passing scsi_mod."
1114 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1115 scsi_inq_str(vend, result, 8, 16),
1116 scsi_inq_str(mod, result, 16, 32));
1121 res = SCSI_SCAN_TARGET_PRESENT;
1122 goto out_free_result;
1126 * Some targets may set slight variations of PQ and PDT to signal
1127 * that no LUN is present, so don't add sdev in these cases.
1128 * Two specific examples are:
1129 * 1) NetApp targets: return PQ=1, PDT=0x1f
1130 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1131 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1134 * 1) SCSI SPC-3, pp. 145-146
1135 * PQ=1: "A peripheral device having the specified peripheral
1136 * device type is not connected to this logical unit. However, the
1137 * device server is capable of supporting the specified peripheral
1138 * device type on this logical unit."
1139 * PDT=0x1f: "Unknown or no device type"
1140 * 2) USB UFI 1.0, p. 20
1141 * PDT=00h Direct-access device (floppy)
1142 * PDT=1Fh none (no FDD connected to the requested logical unit)
1144 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
1145 (result[0] & 0x1f) == 0x1f &&
1146 !scsi_is_wlun(lun)) {
1147 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1148 "scsi scan: peripheral device type"
1149 " of 31, no device added\n"));
1150 res = SCSI_SCAN_TARGET_PRESENT;
1151 goto out_free_result;
1154 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1155 if (res == SCSI_SCAN_LUN_PRESENT) {
1156 if (bflags & BLIST_KEY) {
1158 scsi_unlock_floptical(sdev, result);
1165 if (res == SCSI_SCAN_LUN_PRESENT) {
1167 if (scsi_device_get(sdev) == 0) {
1170 __scsi_remove_device(sdev);
1171 res = SCSI_SCAN_NO_RESPONSE;
1175 __scsi_remove_device(sdev);
1181 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1182 * @starget: pointer to target structure to scan
1183 * @bflags: black/white list flag for LUN 0
1184 * @scsi_level: Which version of the standard does this device adhere to
1185 * @rescan: passed to scsi_probe_add_lun()
1188 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1189 * scanned) to some maximum lun until a LUN is found with no device
1190 * attached. Use the bflags to figure out any oddities.
1192 * Modifies sdevscan->lun.
1194 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1195 int bflags, int scsi_level, int rescan)
1198 u64 sparse_lun, lun;
1199 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1201 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
1202 "scsi scan: Sequential scan\n"));
1204 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1206 * If this device is known to support sparse multiple units,
1207 * override the other settings, and scan all of them. Normally,
1208 * SCSI-3 devices should be scanned via the REPORT LUNS.
1210 if (bflags & BLIST_SPARSELUN) {
1211 max_dev_lun = shost->max_lun;
1217 * If less than SCSI_1_CSS, and no special lun scaning, stop
1218 * scanning; this matches 2.4 behaviour, but could just be a bug
1219 * (to continue scanning a SCSI_1_CSS device).
1221 * This test is broken. We might not have any device on lun0 for
1222 * a sparselun device, and if that's the case then how would we
1223 * know the real scsi_level, eh? It might make sense to just not
1224 * scan any SCSI_1 device for non-0 luns, but that check would best
1225 * go into scsi_alloc_sdev() and just have it return null when asked
1226 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1228 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1229 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1234 * If this device is known to support multiple units, override
1235 * the other settings, and scan all of them.
1237 if (bflags & BLIST_FORCELUN)
1238 max_dev_lun = shost->max_lun;
1240 * REGAL CDC-4X: avoid hang after LUN 4
1242 if (bflags & BLIST_MAX5LUN)
1243 max_dev_lun = min(5U, max_dev_lun);
1245 * Do not scan SCSI-2 or lower device past LUN 7, unless
1248 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1249 max_dev_lun = min(8U, max_dev_lun);
1252 * Stop scanning at 255 unless BLIST_SCSI3LUN
1254 if (!(bflags & BLIST_SCSI3LUN))
1255 max_dev_lun = min(256U, max_dev_lun);
1258 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1259 * until we reach the max, or no LUN is found and we are not
1262 for (lun = 1; lun < max_dev_lun; ++lun)
1263 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1264 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1270 * scsilun_to_int - convert a scsi_lun to an int
1271 * @scsilun: struct scsi_lun to be converted.
1274 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1275 * integer, and return the result. The caller must check for
1276 * truncation before using this function.
1279 * For a description of the LUN format, post SCSI-3 see the SCSI
1280 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1282 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
1283 * returns the integer: 0x0b03d204
1285 * This encoding will return a standard integer LUN for LUNs smaller
1286 * than 256, which typically use a single level LUN structure with
1287 * addressing method 0.
1289 u64 scsilun_to_int(struct scsi_lun *scsilun)
1295 for (i = 0; i < sizeof(lun); i += 2)
1296 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
1297 ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
1300 EXPORT_SYMBOL(scsilun_to_int);
1303 * int_to_scsilun - reverts an int into a scsi_lun
1304 * @lun: integer to be reverted
1305 * @scsilun: struct scsi_lun to be set.
1308 * Reverts the functionality of the scsilun_to_int, which packed
1309 * an 8-byte lun value into an int. This routine unpacks the int
1310 * back into the lun value.
1313 * Given an integer : 0x0b03d204, this function returns a
1314 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
1317 void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
1321 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1323 for (i = 0; i < sizeof(lun); i += 2) {
1324 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1325 scsilun->scsi_lun[i+1] = lun & 0xFF;
1329 EXPORT_SYMBOL(int_to_scsilun);
1332 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1333 * @starget: which target
1334 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1335 * @rescan: nonzero if we can skip code only needed on first scan
1338 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1339 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1341 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1342 * LUNs even if it's older than SCSI-3.
1343 * If BLIST_NOREPORTLUN is set, return 1 always.
1344 * If BLIST_NOLUN is set, return 0 always.
1345 * If starget->no_report_luns is set, return 1 always.
1348 * 0: scan completed (or no memory, so further scanning is futile)
1349 * 1: could not scan with REPORT LUN
1351 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1355 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1356 unsigned int length;
1358 unsigned int num_luns;
1359 unsigned int retries;
1361 struct scsi_lun *lunp, *lun_data;
1363 struct scsi_sense_hdr sshdr;
1364 struct scsi_device *sdev;
1365 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1369 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1370 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1371 * support more than 8 LUNs.
1372 * Don't attempt if the target doesn't support REPORT LUNS.
1374 if (bflags & BLIST_NOREPORTLUN)
1376 if (starget->scsi_level < SCSI_2 &&
1377 starget->scsi_level != SCSI_UNKNOWN)
1379 if (starget->scsi_level < SCSI_3 &&
1380 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1382 if (bflags & BLIST_NOLUN)
1384 if (starget->no_report_luns)
1387 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1388 sdev = scsi_alloc_sdev(starget, 0, NULL);
1391 if (scsi_device_get(sdev)) {
1392 __scsi_remove_device(sdev);
1397 sprintf(devname, "host %d channel %d id %d",
1398 shost->host_no, sdev->channel, sdev->id);
1401 * Allocate enough to hold the header (the same size as one scsi_lun)
1402 * plus the max number of luns we are requesting.
1404 * Reallocating and trying again (with the exact amount we need)
1405 * would be nice, but then we need to somehow limit the size
1406 * allocated based on the available memory and the limits of
1407 * kmalloc - we don't want a kmalloc() failure of a huge value to
1408 * prevent us from finding any LUNs on this target.
1410 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1411 lun_data = kmalloc(length, GFP_ATOMIC |
1412 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1414 printk(ALLOC_FAILURE_MSG, __func__);
1418 scsi_cmd[0] = REPORT_LUNS;
1421 * bytes 1 - 5: reserved, set to zero.
1423 memset(&scsi_cmd[1], 0, 5);
1426 * bytes 6 - 9: length of the command.
1428 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1429 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1430 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1431 scsi_cmd[9] = (unsigned char) length & 0xff;
1433 scsi_cmd[10] = 0; /* reserved */
1434 scsi_cmd[11] = 0; /* control */
1437 * We can get a UNIT ATTENTION, for example a power on/reset, so
1438 * retry a few times (like sd.c does for TEST UNIT READY).
1439 * Experience shows some combinations of adapter/devices get at
1440 * least two power on/resets.
1442 * Illegal requests (for devices that do not support REPORT LUNS)
1443 * should come through as a check condition, and will not generate
1446 for (retries = 0; retries < 3; retries++) {
1447 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1448 "scsi scan: Sending REPORT LUNS to (try %d)\n",
1451 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1452 lun_data, length, &sshdr,
1453 SCSI_TIMEOUT + 4 * HZ, 3, NULL);
1455 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1456 "scsi scan: REPORT LUNS"
1457 " %s (try %d) result 0x%x\n",
1458 result ? "failed" : "successful",
1462 else if (scsi_sense_valid(&sshdr)) {
1463 if (sshdr.sense_key != UNIT_ATTENTION)
1470 * The device probably does not support a REPORT LUN command
1477 * Get the length from the first four bytes of lun_data.
1479 data = (u8 *) lun_data->scsi_lun;
1480 length = ((data[0] << 24) | (data[1] << 16) |
1481 (data[2] << 8) | (data[3] << 0));
1483 num_luns = (length / sizeof(struct scsi_lun));
1484 if (num_luns > max_scsi_report_luns) {
1485 sdev_printk(KERN_WARNING, sdev,
1486 "Only %d (max_scsi_report_luns)"
1487 " of %d luns reported, try increasing"
1488 " max_scsi_report_luns.\n",
1489 max_scsi_report_luns, num_luns);
1490 num_luns = max_scsi_report_luns;
1493 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1494 "scsi scan: REPORT LUN scan\n"));
1497 * Scan the luns in lun_data. The entry at offset 0 is really
1498 * the header, so start at 1 and go up to and including num_luns.
1500 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1501 lun = scsilun_to_int(lunp);
1503 if (lun > sdev->host->max_lun) {
1504 sdev_printk(KERN_WARNING, sdev,
1505 "lun%llu has a LUN larger than"
1506 " allowed by the host adapter\n", lun);
1510 res = scsi_probe_and_add_lun(starget,
1511 lun, NULL, NULL, rescan, NULL);
1512 if (res == SCSI_SCAN_NO_RESPONSE) {
1514 * Got some results, but now none, abort.
1516 sdev_printk(KERN_ERR, sdev,
1517 "Unexpected response"
1518 " from lun %llu while scanning, scan"
1519 " aborted\n", (unsigned long long)lun);
1528 scsi_device_put(sdev);
1529 if (scsi_device_created(sdev))
1531 * the sdev we used didn't appear in the report luns scan
1533 __scsi_remove_device(sdev);
1537 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1538 uint id, u64 lun, void *hostdata)
1540 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1541 struct device *parent = &shost->shost_gendev;
1542 struct scsi_target *starget;
1544 if (strncmp(scsi_scan_type, "none", 4) == 0)
1545 return ERR_PTR(-ENODEV);
1547 starget = scsi_alloc_target(parent, channel, id);
1549 return ERR_PTR(-ENOMEM);
1550 scsi_autopm_get_target(starget);
1552 mutex_lock(&shost->scan_mutex);
1553 if (!shost->async_scan)
1554 scsi_complete_async_scans();
1556 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1557 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1558 scsi_autopm_put_host(shost);
1560 mutex_unlock(&shost->scan_mutex);
1561 scsi_autopm_put_target(starget);
1563 * paired with scsi_alloc_target(). Target will be destroyed unless
1564 * scsi_probe_and_add_lun made an underlying device visible
1566 scsi_target_reap(starget);
1567 put_device(&starget->dev);
1571 EXPORT_SYMBOL(__scsi_add_device);
1573 int scsi_add_device(struct Scsi_Host *host, uint channel,
1574 uint target, u64 lun)
1576 struct scsi_device *sdev =
1577 __scsi_add_device(host, channel, target, lun, NULL);
1579 return PTR_ERR(sdev);
1581 scsi_device_put(sdev);
1584 EXPORT_SYMBOL(scsi_add_device);
1586 void scsi_rescan_device(struct device *dev)
1588 struct scsi_driver *drv;
1593 drv = to_scsi_driver(dev->driver);
1594 if (try_module_get(drv->owner)) {
1597 module_put(drv->owner);
1600 EXPORT_SYMBOL(scsi_rescan_device);
1602 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1603 unsigned int id, u64 lun, int rescan)
1605 struct Scsi_Host *shost = dev_to_shost(parent);
1608 struct scsi_target *starget;
1610 if (shost->this_id == id)
1612 * Don't scan the host adapter
1616 starget = scsi_alloc_target(parent, channel, id);
1619 scsi_autopm_get_target(starget);
1621 if (lun != SCAN_WILD_CARD) {
1623 * Scan for a specific host/chan/id/lun.
1625 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1630 * Scan LUN 0, if there is some response, scan further. Ideally, we
1631 * would not configure LUN 0 until all LUNs are scanned.
1633 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1634 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1635 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1637 * The REPORT LUN did not scan the target,
1638 * do a sequential scan.
1640 scsi_sequential_lun_scan(starget, bflags,
1641 starget->scsi_level, rescan);
1645 scsi_autopm_put_target(starget);
1647 * paired with scsi_alloc_target(): determine if the target has
1648 * any children at all and if not, nuke it
1650 scsi_target_reap(starget);
1652 put_device(&starget->dev);
1656 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1657 * @parent: host to scan
1658 * @channel: channel to scan
1659 * @id: target id to scan
1660 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1661 * @rescan: passed to LUN scanning routines
1664 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1665 * and possibly all LUNs on the target id.
1667 * First try a REPORT LUN scan, if that does not scan the target, do a
1668 * sequential scan of LUNs on the target id.
1670 void scsi_scan_target(struct device *parent, unsigned int channel,
1671 unsigned int id, u64 lun, int rescan)
1673 struct Scsi_Host *shost = dev_to_shost(parent);
1675 if (strncmp(scsi_scan_type, "none", 4) == 0)
1678 mutex_lock(&shost->scan_mutex);
1679 if (!shost->async_scan)
1680 scsi_complete_async_scans();
1682 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1683 __scsi_scan_target(parent, channel, id, lun, rescan);
1684 scsi_autopm_put_host(shost);
1686 mutex_unlock(&shost->scan_mutex);
1688 EXPORT_SYMBOL(scsi_scan_target);
1690 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1691 unsigned int id, u64 lun, int rescan)
1695 if (id == SCAN_WILD_CARD)
1696 for (id = 0; id < shost->max_id; ++id) {
1698 * XXX adapter drivers when possible (FCP, iSCSI)
1699 * could modify max_id to match the current max,
1700 * not the absolute max.
1702 * XXX add a shost id iterator, so for example,
1703 * the FC ID can be the same as a target id
1704 * without a huge overhead of sparse id's.
1706 if (shost->reverse_ordering)
1708 * Scan from high to low id.
1710 order_id = shost->max_id - id - 1;
1713 __scsi_scan_target(&shost->shost_gendev, channel,
1714 order_id, lun, rescan);
1717 __scsi_scan_target(&shost->shost_gendev, channel,
1721 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1722 unsigned int id, u64 lun, int rescan)
1724 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1725 "%s: <%u:%u:%llu>\n",
1726 __func__, channel, id, lun));
1728 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1729 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1730 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1733 mutex_lock(&shost->scan_mutex);
1734 if (!shost->async_scan)
1735 scsi_complete_async_scans();
1737 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1738 if (channel == SCAN_WILD_CARD)
1739 for (channel = 0; channel <= shost->max_channel;
1741 scsi_scan_channel(shost, channel, id, lun,
1744 scsi_scan_channel(shost, channel, id, lun, rescan);
1745 scsi_autopm_put_host(shost);
1747 mutex_unlock(&shost->scan_mutex);
1752 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1754 struct scsi_device *sdev;
1755 shost_for_each_device(sdev, shost) {
1756 /* target removed before the device could be added */
1757 if (sdev->sdev_state == SDEV_DEL)
1759 /* If device is already visible, skip adding it to sysfs */
1760 if (sdev->is_visible)
1762 if (!scsi_host_scan_allowed(shost) ||
1763 scsi_sysfs_add_sdev(sdev) != 0)
1764 __scsi_remove_device(sdev);
1769 * scsi_prep_async_scan - prepare for an async scan
1770 * @shost: the host which will be scanned
1771 * Returns: a cookie to be passed to scsi_finish_async_scan()
1773 * Tells the midlayer this host is going to do an asynchronous scan.
1774 * It reserves the host's position in the scanning list and ensures
1775 * that other asynchronous scans started after this one won't affect the
1776 * ordering of the discovered devices.
1778 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1780 struct async_scan_data *data;
1781 unsigned long flags;
1783 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1786 if (shost->async_scan) {
1787 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1792 data = kmalloc(sizeof(*data), GFP_KERNEL);
1795 data->shost = scsi_host_get(shost);
1798 init_completion(&data->prev_finished);
1800 mutex_lock(&shost->scan_mutex);
1801 spin_lock_irqsave(shost->host_lock, flags);
1802 shost->async_scan = 1;
1803 spin_unlock_irqrestore(shost->host_lock, flags);
1804 mutex_unlock(&shost->scan_mutex);
1806 spin_lock(&async_scan_lock);
1807 if (list_empty(&scanning_hosts))
1808 complete(&data->prev_finished);
1809 list_add_tail(&data->list, &scanning_hosts);
1810 spin_unlock(&async_scan_lock);
1820 * scsi_finish_async_scan - asynchronous scan has finished
1821 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1823 * All the devices currently attached to this host have been found.
1824 * This function announces all the devices it has found to the rest
1827 static void scsi_finish_async_scan(struct async_scan_data *data)
1829 struct Scsi_Host *shost;
1830 unsigned long flags;
1835 shost = data->shost;
1837 mutex_lock(&shost->scan_mutex);
1839 if (!shost->async_scan) {
1840 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1842 mutex_unlock(&shost->scan_mutex);
1846 wait_for_completion(&data->prev_finished);
1848 scsi_sysfs_add_devices(shost);
1850 spin_lock_irqsave(shost->host_lock, flags);
1851 shost->async_scan = 0;
1852 spin_unlock_irqrestore(shost->host_lock, flags);
1854 mutex_unlock(&shost->scan_mutex);
1856 spin_lock(&async_scan_lock);
1857 list_del(&data->list);
1858 if (!list_empty(&scanning_hosts)) {
1859 struct async_scan_data *next = list_entry(scanning_hosts.next,
1860 struct async_scan_data, list);
1861 complete(&next->prev_finished);
1863 spin_unlock(&async_scan_lock);
1865 scsi_autopm_put_host(shost);
1866 scsi_host_put(shost);
1870 static void do_scsi_scan_host(struct Scsi_Host *shost)
1872 if (shost->hostt->scan_finished) {
1873 unsigned long start = jiffies;
1874 if (shost->hostt->scan_start)
1875 shost->hostt->scan_start(shost);
1877 while (!shost->hostt->scan_finished(shost, jiffies - start))
1880 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1885 static void do_scan_async(void *_data, async_cookie_t c)
1887 struct async_scan_data *data = _data;
1888 struct Scsi_Host *shost = data->shost;
1890 do_scsi_scan_host(shost);
1891 scsi_finish_async_scan(data);
1895 * scsi_scan_host - scan the given adapter
1896 * @shost: adapter to scan
1898 void scsi_scan_host(struct Scsi_Host *shost)
1900 struct async_scan_data *data;
1902 if (strncmp(scsi_scan_type, "none", 4) == 0)
1904 if (scsi_autopm_get_host(shost) < 0)
1907 data = scsi_prep_async_scan(shost);
1909 do_scsi_scan_host(shost);
1910 scsi_autopm_put_host(shost);
1914 /* register with the async subsystem so wait_for_device_probe()
1915 * will flush this work
1917 async_schedule(do_scan_async, data);
1919 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1921 EXPORT_SYMBOL(scsi_scan_host);
1923 void scsi_forget_host(struct Scsi_Host *shost)
1925 struct scsi_device *sdev;
1926 unsigned long flags;
1929 spin_lock_irqsave(shost->host_lock, flags);
1930 list_for_each_entry(sdev, &shost->__devices, siblings) {
1931 if (sdev->sdev_state == SDEV_DEL)
1933 spin_unlock_irqrestore(shost->host_lock, flags);
1934 __scsi_remove_device(sdev);
1937 spin_unlock_irqrestore(shost->host_lock, flags);
1941 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
1942 * @shost: Host that needs a scsi_device
1944 * Lock status: None assumed.
1946 * Returns: The scsi_device or NULL
1949 * Attach a single scsi_device to the Scsi_Host - this should
1950 * be made to look like a "pseudo-device" that points to the
1953 * Note - this device is not accessible from any high-level
1954 * drivers (including generics), which is probably not
1955 * optimal. We can add hooks later to attach.
1957 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1959 struct scsi_device *sdev = NULL;
1960 struct scsi_target *starget;
1962 mutex_lock(&shost->scan_mutex);
1963 if (!scsi_host_scan_allowed(shost))
1965 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1969 sdev = scsi_alloc_sdev(starget, 0, NULL);
1973 scsi_target_reap(starget);
1974 put_device(&starget->dev);
1976 mutex_unlock(&shost->scan_mutex);
1979 EXPORT_SYMBOL(scsi_get_host_dev);
1982 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
1983 * @sdev: Host device to be freed
1985 * Lock status: None assumed.
1989 void scsi_free_host_dev(struct scsi_device *sdev)
1991 BUG_ON(sdev->id != sdev->host->this_id);
1993 __scsi_remove_device(sdev);
1995 EXPORT_SYMBOL(scsi_free_host_dev);