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)
218 struct scsi_device *sdev;
219 int display_failure_msg = 1, ret;
220 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
222 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
227 sdev->vendor = scsi_null_device_strs;
228 sdev->model = scsi_null_device_strs;
229 sdev->rev = scsi_null_device_strs;
231 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
232 sdev->id = starget->id;
234 sdev->channel = starget->channel;
235 mutex_init(&sdev->state_mutex);
236 sdev->sdev_state = SDEV_CREATED;
237 INIT_LIST_HEAD(&sdev->siblings);
238 INIT_LIST_HEAD(&sdev->same_target_siblings);
239 INIT_LIST_HEAD(&sdev->cmd_list);
240 INIT_LIST_HEAD(&sdev->starved_entry);
241 INIT_LIST_HEAD(&sdev->event_list);
242 spin_lock_init(&sdev->list_lock);
243 mutex_init(&sdev->inquiry_mutex);
244 INIT_WORK(&sdev->event_work, scsi_evt_thread);
245 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
247 sdev->sdev_gendev.parent = get_device(&starget->dev);
248 sdev->sdev_target = starget;
250 /* usually NULL and set by ->slave_alloc instead */
251 sdev->hostdata = hostdata;
253 /* if the device needs this changing, it may do so in the
254 * slave_configure function */
255 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
258 * Some low level driver could use device->type
263 * Assume that the device will have handshaking problems,
264 * and then fix this field later if it turns out it
269 sdev->request_queue = scsi_mq_alloc_queue(sdev);
270 if (!sdev->request_queue) {
271 /* release fn is set up in scsi_sysfs_device_initialise, so
272 * have to free and put manually here */
273 put_device(&starget->dev);
277 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
278 sdev->request_queue->queuedata = sdev;
280 scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ?
281 sdev->host->cmd_per_lun : 1);
283 scsi_sysfs_device_initialize(sdev);
285 if (shost->hostt->slave_alloc) {
286 ret = shost->hostt->slave_alloc(sdev);
289 * if LLDD reports slave not present, don't clutter
290 * console with alloc failure messages
293 display_failure_msg = 0;
294 goto out_device_destroy;
301 __scsi_remove_device(sdev);
303 if (display_failure_msg)
304 printk(ALLOC_FAILURE_MSG, __func__);
308 static void scsi_target_destroy(struct scsi_target *starget)
310 struct device *dev = &starget->dev;
311 struct Scsi_Host *shost = dev_to_shost(dev->parent);
314 BUG_ON(starget->state == STARGET_DEL);
315 starget->state = STARGET_DEL;
316 transport_destroy_device(dev);
317 spin_lock_irqsave(shost->host_lock, flags);
318 if (shost->hostt->target_destroy)
319 shost->hostt->target_destroy(starget);
320 list_del_init(&starget->siblings);
321 spin_unlock_irqrestore(shost->host_lock, flags);
325 static void scsi_target_dev_release(struct device *dev)
327 struct device *parent = dev->parent;
328 struct scsi_target *starget = to_scsi_target(dev);
334 static struct device_type scsi_target_type = {
335 .name = "scsi_target",
336 .release = scsi_target_dev_release,
339 int scsi_is_target_device(const struct device *dev)
341 return dev->type == &scsi_target_type;
343 EXPORT_SYMBOL(scsi_is_target_device);
345 static struct scsi_target *__scsi_find_target(struct device *parent,
346 int channel, uint id)
348 struct scsi_target *starget, *found_starget = NULL;
349 struct Scsi_Host *shost = dev_to_shost(parent);
351 * Search for an existing target for this sdev.
353 list_for_each_entry(starget, &shost->__targets, siblings) {
354 if (starget->id == id &&
355 starget->channel == channel) {
356 found_starget = starget;
361 get_device(&found_starget->dev);
363 return found_starget;
367 * scsi_target_reap_ref_release - remove target from visibility
368 * @kref: the reap_ref in the target being released
370 * Called on last put of reap_ref, which is the indication that no device
371 * under this target is visible anymore, so render the target invisible in
372 * sysfs. Note: we have to be in user context here because the target reaps
373 * should be done in places where the scsi device visibility is being removed.
375 static void scsi_target_reap_ref_release(struct kref *kref)
377 struct scsi_target *starget
378 = container_of(kref, struct scsi_target, reap_ref);
381 * if we get here and the target is still in a CREATED state that
382 * means it was allocated but never made visible (because a scan
383 * turned up no LUNs), so don't call device_del() on it.
385 if ((starget->state != STARGET_CREATED) &&
386 (starget->state != STARGET_CREATED_REMOVE)) {
387 transport_remove_device(&starget->dev);
388 device_del(&starget->dev);
390 scsi_target_destroy(starget);
393 static void scsi_target_reap_ref_put(struct scsi_target *starget)
395 kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
399 * scsi_alloc_target - allocate a new or find an existing target
400 * @parent: parent of the target (need not be a scsi host)
401 * @channel: target channel number (zero if no channels)
402 * @id: target id number
404 * Return an existing target if one exists, provided it hasn't already
405 * gone into STARGET_DEL state, otherwise allocate a new target.
407 * The target is returned with an incremented reference, so the caller
408 * is responsible for both reaping and doing a last put
410 static struct scsi_target *scsi_alloc_target(struct device *parent,
411 int channel, uint id)
413 struct Scsi_Host *shost = dev_to_shost(parent);
414 struct device *dev = NULL;
416 const int size = sizeof(struct scsi_target)
417 + shost->transportt->target_size;
418 struct scsi_target *starget;
419 struct scsi_target *found_target;
422 starget = kzalloc(size, GFP_KERNEL);
424 printk(KERN_ERR "%s: allocation failure\n", __func__);
428 device_initialize(dev);
429 kref_init(&starget->reap_ref);
430 dev->parent = get_device(parent);
431 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
432 dev->bus = &scsi_bus_type;
433 dev->type = &scsi_target_type;
435 starget->channel = channel;
436 starget->can_queue = 0;
437 INIT_LIST_HEAD(&starget->siblings);
438 INIT_LIST_HEAD(&starget->devices);
439 starget->state = STARGET_CREATED;
440 starget->scsi_level = SCSI_2;
441 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
443 spin_lock_irqsave(shost->host_lock, flags);
445 found_target = __scsi_find_target(parent, channel, id);
449 list_add_tail(&starget->siblings, &shost->__targets);
450 spin_unlock_irqrestore(shost->host_lock, flags);
451 /* allocate and add */
452 transport_setup_device(dev);
453 if (shost->hostt->target_alloc) {
454 error = shost->hostt->target_alloc(starget);
458 dev_err(dev, "target allocation failed, error %d\n", error);
459 /* don't want scsi_target_reap to do the final
460 * put because it will be under the host lock */
461 scsi_target_destroy(starget);
471 * release routine already fired if kref is zero, so if we can still
472 * take the reference, the target must be alive. If we can't, it must
473 * be dying and we need to wait for a new target
475 ref_got = kref_get_unless_zero(&found_target->reap_ref);
477 spin_unlock_irqrestore(shost->host_lock, flags);
483 * Unfortunately, we found a dying target; need to wait until it's
484 * dead before we can get a new one. There is an anomaly here. We
485 * *should* call scsi_target_reap() to balance the kref_get() of the
486 * reap_ref above. However, since the target being released, it's
487 * already invisible and the reap_ref is irrelevant. If we call
488 * scsi_target_reap() we might spuriously do another device_del() on
489 * an already invisible target.
491 put_device(&found_target->dev);
493 * length of time is irrelevant here, we just want to yield the CPU
494 * for a tick to avoid busy waiting for the target to die.
501 * scsi_target_reap - check to see if target is in use and destroy if not
502 * @starget: target to be checked
504 * This is used after removing a LUN or doing a last put of the target
505 * it checks atomically that nothing is using the target and removes
508 void scsi_target_reap(struct scsi_target *starget)
511 * serious problem if this triggers: STARGET_DEL is only set in the if
512 * the reap_ref drops to zero, so we're trying to do another final put
513 * on an already released kref
515 BUG_ON(starget->state == STARGET_DEL);
516 scsi_target_reap_ref_put(starget);
520 * scsi_sanitize_inquiry_string - remove non-graphical chars from an
521 * INQUIRY result string
522 * @s: INQUIRY result string to sanitize
523 * @len: length of the string
526 * The SCSI spec says that INQUIRY vendor, product, and revision
527 * strings must consist entirely of graphic ASCII characters,
528 * padded on the right with spaces. Since not all devices obey
529 * this rule, we will replace non-graphic or non-ASCII characters
530 * with spaces. Exception: a NUL character is interpreted as a
531 * string terminator, so all the following characters are set to
534 void scsi_sanitize_inquiry_string(unsigned char *s, int len)
538 for (; len > 0; (--len, ++s)) {
541 if (terminated || *s < 0x20 || *s > 0x7e)
545 EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
548 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
549 * @sdev: scsi_device to probe
550 * @inq_result: area to store the INQUIRY result
551 * @result_len: len of inq_result
552 * @bflags: store any bflags found here
555 * Probe the lun associated with @req using a standard SCSI INQUIRY;
557 * If the INQUIRY is successful, zero is returned and the
558 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
559 * are copied to the scsi_device any flags value is stored in *@bflags.
561 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
562 int result_len, blist_flags_t *bflags)
564 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
565 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
566 int response_len = 0;
567 int pass, count, result;
568 struct scsi_sense_hdr sshdr;
572 /* Perform up to 3 passes. The first pass uses a conservative
573 * transfer length of 36 unless sdev->inquiry_len specifies a
574 * different value. */
575 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
576 try_inquiry_len = first_inquiry_len;
580 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
581 "scsi scan: INQUIRY pass %d length %d\n",
582 pass, try_inquiry_len));
584 /* Each pass gets up to three chances to ignore Unit Attention */
585 for (count = 0; count < 3; ++count) {
588 memset(scsi_cmd, 0, 6);
589 scsi_cmd[0] = INQUIRY;
590 scsi_cmd[4] = (unsigned char) try_inquiry_len;
592 memset(inq_result, 0, try_inquiry_len);
594 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
595 inq_result, try_inquiry_len, &sshdr,
596 HZ / 2 + HZ * scsi_inq_timeout, 3,
599 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
600 "scsi scan: INQUIRY %s with code 0x%x\n",
601 result ? "failed" : "successful", result));
605 * not-ready to ready transition [asc/ascq=0x28/0x0]
606 * or power-on, reset [asc/ascq=0x29/0x0], continue.
607 * INQUIRY should not yield UNIT_ATTENTION
608 * but many buggy devices do so anyway.
610 if (driver_byte(result) == DRIVER_SENSE &&
611 scsi_sense_valid(&sshdr)) {
612 if ((sshdr.sense_key == UNIT_ATTENTION) &&
613 ((sshdr.asc == 0x28) ||
614 (sshdr.asc == 0x29)) &&
620 * if nothing was transferred, we try
621 * again. It's a workaround for some USB
624 if (resid == try_inquiry_len)
631 scsi_sanitize_inquiry_string(&inq_result[8], 8);
632 scsi_sanitize_inquiry_string(&inq_result[16], 16);
633 scsi_sanitize_inquiry_string(&inq_result[32], 4);
635 response_len = inq_result[4] + 5;
636 if (response_len > 255)
637 response_len = first_inquiry_len; /* sanity */
640 * Get any flags for this device.
642 * XXX add a bflags to scsi_device, and replace the
643 * corresponding bit fields in scsi_device, so bflags
644 * need not be passed as an argument.
646 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
649 /* When the first pass succeeds we gain information about
650 * what larger transfer lengths might work. */
652 if (BLIST_INQUIRY_36 & *bflags)
653 next_inquiry_len = 36;
654 else if (sdev->inquiry_len)
655 next_inquiry_len = sdev->inquiry_len;
657 next_inquiry_len = response_len;
659 /* If more data is available perform the second pass */
660 if (next_inquiry_len > try_inquiry_len) {
661 try_inquiry_len = next_inquiry_len;
667 } else if (pass == 2) {
668 sdev_printk(KERN_INFO, sdev,
669 "scsi scan: %d byte inquiry failed. "
670 "Consider BLIST_INQUIRY_36 for this device\n",
673 /* If this pass failed, the third pass goes back and transfers
674 * the same amount as we successfully got in the first pass. */
675 try_inquiry_len = first_inquiry_len;
680 /* If the last transfer attempt got an error, assume the
681 * peripheral doesn't exist or is dead. */
685 /* Don't report any more data than the device says is valid */
686 sdev->inquiry_len = min(try_inquiry_len, response_len);
689 * XXX Abort if the response length is less than 36? If less than
690 * 32, the lookup of the device flags (above) could be invalid,
691 * and it would be possible to take an incorrect action - we do
692 * not want to hang because of a short INQUIRY. On the flip side,
693 * if the device is spun down or becoming ready (and so it gives a
694 * short INQUIRY), an abort here prevents any further use of the
695 * device, including spin up.
697 * On the whole, the best approach seems to be to assume the first
698 * 36 bytes are valid no matter what the device says. That's
699 * better than copying < 36 bytes to the inquiry-result buffer
700 * and displaying garbage for the Vendor, Product, or Revision
703 if (sdev->inquiry_len < 36) {
704 if (!sdev->host->short_inquiry) {
705 shost_printk(KERN_INFO, sdev->host,
706 "scsi scan: INQUIRY result too short (%d),"
707 " using 36\n", sdev->inquiry_len);
708 sdev->host->short_inquiry = 1;
710 sdev->inquiry_len = 36;
714 * Related to the above issue:
716 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
717 * and if not ready, sent a START_STOP to start (maybe spin up) and
718 * then send the INQUIRY again, since the INQUIRY can change after
719 * a device is initialized.
721 * Ideally, start a device if explicitly asked to do so. This
722 * assumes that a device is spun up on power on, spun down on
723 * request, and then spun up on request.
727 * The scanning code needs to know the scsi_level, even if no
728 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
729 * non-zero LUNs can be scanned.
731 sdev->scsi_level = inq_result[2] & 0x07;
732 if (sdev->scsi_level >= 2 ||
733 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
735 sdev->sdev_target->scsi_level = sdev->scsi_level;
738 * If SCSI-2 or lower, and if the transport requires it,
739 * store the LUN value in CDB[1].
741 sdev->lun_in_cdb = 0;
742 if (sdev->scsi_level <= SCSI_2 &&
743 sdev->scsi_level != SCSI_UNKNOWN &&
744 !sdev->host->no_scsi2_lun_in_cdb)
745 sdev->lun_in_cdb = 1;
751 * scsi_add_lun - allocate and fully initialze a scsi_device
752 * @sdev: holds information to be stored in the new scsi_device
753 * @inq_result: holds the result of a previous INQUIRY to the LUN
754 * @bflags: black/white list flag
755 * @async: 1 if this device is being scanned asynchronously
758 * Initialize the scsi_device @sdev. Optionally set fields based
759 * on values in *@bflags.
762 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
763 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
765 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
766 blist_flags_t *bflags, int async)
771 * XXX do not save the inquiry, since it can change underneath us,
772 * save just vendor/model/rev.
774 * Rather than save it and have an ioctl that retrieves the saved
775 * value, have an ioctl that executes the same INQUIRY code used
776 * in scsi_probe_lun, let user level programs doing INQUIRY
777 * scanning run at their own risk, or supply a user level program
778 * that can correctly scan.
782 * Copy at least 36 bytes of INQUIRY data, so that we don't
783 * dereference unallocated memory when accessing the Vendor,
784 * Product, and Revision strings. Badly behaved devices may set
785 * the INQUIRY Additional Length byte to a small value, indicating
786 * these strings are invalid, but often they contain plausible data
787 * nonetheless. It doesn't matter if the device sent < 36 bytes
788 * total, since scsi_probe_lun() initializes inq_result with 0s.
790 sdev->inquiry = kmemdup(inq_result,
791 max_t(size_t, sdev->inquiry_len, 36),
793 if (sdev->inquiry == NULL)
794 return SCSI_SCAN_NO_RESPONSE;
796 sdev->vendor = (char *) (sdev->inquiry + 8);
797 sdev->model = (char *) (sdev->inquiry + 16);
798 sdev->rev = (char *) (sdev->inquiry + 32);
800 if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
802 * sata emulation layer device. This is a hack to work around
803 * the SATL power management specifications which state that
804 * when the SATL detects the device has gone into standby
805 * mode, it shall respond with NOT READY.
807 sdev->allow_restart = 1;
810 if (*bflags & BLIST_ISROM) {
811 sdev->type = TYPE_ROM;
814 sdev->type = (inq_result[0] & 0x1f);
815 sdev->removable = (inq_result[1] & 0x80) >> 7;
818 * some devices may respond with wrong type for
819 * well-known logical units. Force well-known type
820 * to enumerate them correctly.
822 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
823 sdev_printk(KERN_WARNING, sdev,
824 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
825 __func__, sdev->type, (unsigned int)sdev->lun);
826 sdev->type = TYPE_WLUN;
831 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
832 /* RBC and MMC devices can return SCSI-3 compliance and yet
833 * still not support REPORT LUNS, so make them act as
834 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
835 * specifically set */
836 if ((*bflags & BLIST_REPORTLUN2) == 0)
837 *bflags |= BLIST_NOREPORTLUN;
841 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
842 * spec says: The device server is capable of supporting the
843 * specified peripheral device type on this logical unit. However,
844 * the physical device is not currently connected to this logical
847 * The above is vague, as it implies that we could treat 001 and
848 * 011 the same. Stay compatible with previous code, and create a
849 * scsi_device for a PQ of 1
851 * Don't set the device offline here; rather let the upper
852 * level drivers eval the PQ to decide whether they should
853 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
856 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
857 sdev->lockable = sdev->removable;
858 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
860 if (sdev->scsi_level >= SCSI_3 ||
861 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
863 if (inq_result[7] & 0x60)
865 if (inq_result[7] & 0x10)
868 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
869 "ANSI: %d%s\n", scsi_device_type(sdev->type),
870 sdev->vendor, sdev->model, sdev->rev,
871 sdev->inq_periph_qual, inq_result[2] & 0x07,
872 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
874 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
875 !(*bflags & BLIST_NOTQ)) {
876 sdev->tagged_supported = 1;
877 sdev->simple_tags = 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);
905 * Max 1024 sector transfer length for targets that report incorrect
906 * max/optimal lengths and relied on the old block layer safe default
908 else if (*bflags & BLIST_MAX_1024)
909 blk_queue_max_hw_sectors(sdev->request_queue, 1024);
912 * Some devices may not want to have a start command automatically
913 * issued when a device is added.
915 if (*bflags & BLIST_NOSTARTONADD)
916 sdev->no_start_on_add = 1;
918 if (*bflags & BLIST_SINGLELUN)
919 scsi_target(sdev)->single_lun = 1;
921 sdev->use_10_for_rw = 1;
923 /* some devices don't like REPORT SUPPORTED OPERATION CODES
924 * and will simply timeout causing sd_mod init to take a very
926 if (*bflags & BLIST_NO_RSOC)
927 sdev->no_report_opcodes = 1;
929 /* set the device running here so that slave configure
931 mutex_lock(&sdev->state_mutex);
932 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
934 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
935 mutex_unlock(&sdev->state_mutex);
938 sdev_printk(KERN_ERR, sdev,
939 "in wrong state %s to complete scan\n",
940 scsi_device_state_name(sdev->sdev_state));
941 return SCSI_SCAN_NO_RESPONSE;
944 if (*bflags & BLIST_NOT_LOCKABLE)
947 if (*bflags & BLIST_RETRY_HWERROR)
948 sdev->retry_hwerror = 1;
950 if (*bflags & BLIST_NO_DIF)
953 if (*bflags & BLIST_UNMAP_LIMIT_WS)
954 sdev->unmap_limit_for_ws = 1;
956 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
958 if (*bflags & BLIST_TRY_VPD_PAGES)
959 sdev->try_vpd_pages = 1;
960 else if (*bflags & BLIST_SKIP_VPD_PAGES)
961 sdev->skip_vpd_pages = 1;
963 transport_configure_device(&sdev->sdev_gendev);
965 if (sdev->host->hostt->slave_configure) {
966 ret = sdev->host->hostt->slave_configure(sdev);
969 * if LLDD reports slave not present, don't clutter
970 * console with alloc failure messages
973 sdev_printk(KERN_ERR, sdev,
974 "failed to configure device\n");
976 return SCSI_SCAN_NO_RESPONSE;
980 if (sdev->scsi_level >= SCSI_3)
981 scsi_attach_vpd(sdev);
983 sdev->max_queue_depth = sdev->queue_depth;
984 sdev->sdev_bflags = *bflags;
987 * Ok, the device is now all set up, we can
988 * register it and tell the rest of the kernel
991 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
992 return SCSI_SCAN_NO_RESPONSE;
994 return SCSI_SCAN_LUN_PRESENT;
997 #ifdef CONFIG_SCSI_LOGGING
999 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
1000 * @buf: Output buffer with at least end-first+1 bytes of space
1001 * @inq: Inquiry buffer (input)
1002 * @first: Offset of string into inq
1003 * @end: Index after last character in inq
1005 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
1006 unsigned first, unsigned end)
1008 unsigned term = 0, idx;
1010 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1011 if (inq[idx+first] > ' ') {
1012 buf[idx] = inq[idx+first];
1024 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1025 * @starget: pointer to target device structure
1026 * @lun: LUN of target device
1027 * @bflagsp: store bflags here if not NULL
1028 * @sdevp: probe the LUN corresponding to this scsi_device
1029 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only
1030 * 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.
1039 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1040 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1041 * attached at the LUN
1042 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1044 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1045 u64 lun, blist_flags_t *bflagsp,
1046 struct scsi_device **sdevp,
1047 enum scsi_scan_mode rescan,
1050 struct scsi_device *sdev;
1051 unsigned char *result;
1052 blist_flags_t bflags;
1053 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1054 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1057 * The rescan flag is used as an optimization, the first scan of a
1058 * host adapter calls into here with rescan == 0.
1060 sdev = scsi_device_lookup_by_target(starget, lun);
1062 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) {
1063 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1064 "scsi scan: device exists on %s\n",
1065 dev_name(&sdev->sdev_gendev)));
1069 scsi_device_put(sdev);
1072 *bflagsp = scsi_get_device_flags(sdev,
1075 return SCSI_SCAN_LUN_PRESENT;
1077 scsi_device_put(sdev);
1079 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1083 result = kmalloc(result_len, GFP_KERNEL |
1084 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1088 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1089 goto out_free_result;
1094 * result contains valid SCSI INQUIRY data.
1096 if ((result[0] >> 5) == 3) {
1098 * For a Peripheral qualifier 3 (011b), the SCSI
1099 * spec says: The device server is not capable of
1100 * supporting a physical device on this logical
1103 * For disks, this implies that there is no
1104 * logical disk configured at sdev->lun, but there
1105 * is a target id responding.
1107 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1108 " peripheral qualifier of 3, device not"
1111 SCSI_LOG_SCAN_BUS(1, {
1112 unsigned char vend[9];
1113 unsigned char mod[17];
1115 sdev_printk(KERN_INFO, sdev,
1116 "scsi scan: consider passing scsi_mod."
1117 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1118 scsi_inq_str(vend, result, 8, 16),
1119 scsi_inq_str(mod, result, 16, 32));
1124 res = SCSI_SCAN_TARGET_PRESENT;
1125 goto out_free_result;
1129 * Some targets may set slight variations of PQ and PDT to signal
1130 * that no LUN is present, so don't add sdev in these cases.
1131 * Two specific examples are:
1132 * 1) NetApp targets: return PQ=1, PDT=0x1f
1133 * 2) IBM/2145 targets: return PQ=1, PDT=0
1134 * 3) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1135 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1138 * 1) SCSI SPC-3, pp. 145-146
1139 * PQ=1: "A peripheral device having the specified peripheral
1140 * device type is not connected to this logical unit. However, the
1141 * device server is capable of supporting the specified peripheral
1142 * device type on this logical unit."
1143 * PDT=0x1f: "Unknown or no device type"
1144 * 2) USB UFI 1.0, p. 20
1145 * PDT=00h Direct-access device (floppy)
1146 * PDT=1Fh none (no FDD connected to the requested logical unit)
1148 if (((result[0] >> 5) == 1 ||
1149 (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f)) &&
1150 !scsi_is_wlun(lun)) {
1151 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1152 "scsi scan: peripheral device type"
1153 " of 31, no device added\n"));
1154 res = SCSI_SCAN_TARGET_PRESENT;
1155 goto out_free_result;
1158 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1159 if (res == SCSI_SCAN_LUN_PRESENT) {
1160 if (bflags & BLIST_KEY) {
1162 scsi_unlock_floptical(sdev, result);
1169 if (res == SCSI_SCAN_LUN_PRESENT) {
1171 if (scsi_device_get(sdev) == 0) {
1174 __scsi_remove_device(sdev);
1175 res = SCSI_SCAN_NO_RESPONSE;
1179 __scsi_remove_device(sdev);
1185 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1186 * @starget: pointer to target structure to scan
1187 * @bflags: black/white list flag for LUN 0
1188 * @scsi_level: Which version of the standard does this device adhere to
1189 * @rescan: passed to scsi_probe_add_lun()
1192 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1193 * scanned) to some maximum lun until a LUN is found with no device
1194 * attached. Use the bflags to figure out any oddities.
1196 * Modifies sdevscan->lun.
1198 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1199 blist_flags_t bflags, int scsi_level,
1200 enum scsi_scan_mode rescan)
1203 u64 sparse_lun, lun;
1204 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1206 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
1207 "scsi scan: Sequential scan\n"));
1209 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1211 * If this device is known to support sparse multiple units,
1212 * override the other settings, and scan all of them. Normally,
1213 * SCSI-3 devices should be scanned via the REPORT LUNS.
1215 if (bflags & BLIST_SPARSELUN) {
1216 max_dev_lun = shost->max_lun;
1222 * If less than SCSI_1_CCS, and no special lun scanning, stop
1223 * scanning; this matches 2.4 behaviour, but could just be a bug
1224 * (to continue scanning a SCSI_1_CCS device).
1226 * This test is broken. We might not have any device on lun0 for
1227 * a sparselun device, and if that's the case then how would we
1228 * know the real scsi_level, eh? It might make sense to just not
1229 * scan any SCSI_1 device for non-0 luns, but that check would best
1230 * go into scsi_alloc_sdev() and just have it return null when asked
1231 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1233 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1234 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1239 * If this device is known to support multiple units, override
1240 * the other settings, and scan all of them.
1242 if (bflags & BLIST_FORCELUN)
1243 max_dev_lun = shost->max_lun;
1245 * REGAL CDC-4X: avoid hang after LUN 4
1247 if (bflags & BLIST_MAX5LUN)
1248 max_dev_lun = min(5U, max_dev_lun);
1250 * Do not scan SCSI-2 or lower device past LUN 7, unless
1253 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1254 max_dev_lun = min(8U, max_dev_lun);
1256 max_dev_lun = min(256U, max_dev_lun);
1259 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1260 * until we reach the max, or no LUN is found and we are not
1263 for (lun = 1; lun < max_dev_lun; ++lun)
1264 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1265 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1271 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1272 * @starget: which target
1273 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1274 * @rescan: nonzero if we can skip code only needed on first scan
1277 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1278 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1280 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1281 * LUNs even if it's older than SCSI-3.
1282 * If BLIST_NOREPORTLUN is set, return 1 always.
1283 * If BLIST_NOLUN is set, return 0 always.
1284 * If starget->no_report_luns is set, return 1 always.
1287 * 0: scan completed (or no memory, so further scanning is futile)
1288 * 1: could not scan with REPORT LUN
1290 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags,
1291 enum scsi_scan_mode rescan)
1293 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1294 unsigned int length;
1296 unsigned int num_luns;
1297 unsigned int retries;
1299 struct scsi_lun *lunp, *lun_data;
1300 struct scsi_sense_hdr sshdr;
1301 struct scsi_device *sdev;
1302 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1306 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1307 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1308 * support more than 8 LUNs.
1309 * Don't attempt if the target doesn't support REPORT LUNS.
1311 if (bflags & BLIST_NOREPORTLUN)
1313 if (starget->scsi_level < SCSI_2 &&
1314 starget->scsi_level != SCSI_UNKNOWN)
1316 if (starget->scsi_level < SCSI_3 &&
1317 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1319 if (bflags & BLIST_NOLUN)
1321 if (starget->no_report_luns)
1324 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1325 sdev = scsi_alloc_sdev(starget, 0, NULL);
1328 if (scsi_device_get(sdev)) {
1329 __scsi_remove_device(sdev);
1335 * Allocate enough to hold the header (the same size as one scsi_lun)
1336 * plus the number of luns we are requesting. 511 was the default
1337 * value of the now removed max_report_luns parameter.
1339 length = (511 + 1) * sizeof(struct scsi_lun);
1341 lun_data = kmalloc(length, GFP_KERNEL |
1342 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1344 printk(ALLOC_FAILURE_MSG, __func__);
1348 scsi_cmd[0] = REPORT_LUNS;
1351 * bytes 1 - 5: reserved, set to zero.
1353 memset(&scsi_cmd[1], 0, 5);
1356 * bytes 6 - 9: length of the command.
1358 put_unaligned_be32(length, &scsi_cmd[6]);
1360 scsi_cmd[10] = 0; /* reserved */
1361 scsi_cmd[11] = 0; /* control */
1364 * We can get a UNIT ATTENTION, for example a power on/reset, so
1365 * retry a few times (like sd.c does for TEST UNIT READY).
1366 * Experience shows some combinations of adapter/devices get at
1367 * least two power on/resets.
1369 * Illegal requests (for devices that do not support REPORT LUNS)
1370 * should come through as a check condition, and will not generate
1373 for (retries = 0; retries < 3; retries++) {
1374 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1375 "scsi scan: Sending REPORT LUNS to (try %d)\n",
1378 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1379 lun_data, length, &sshdr,
1380 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL);
1382 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1383 "scsi scan: REPORT LUNS"
1384 " %s (try %d) result 0x%x\n",
1385 result ? "failed" : "successful",
1389 else if (scsi_sense_valid(&sshdr)) {
1390 if (sshdr.sense_key != UNIT_ATTENTION)
1397 * The device probably does not support a REPORT LUN command
1404 * Get the length from the first four bytes of lun_data.
1406 if (get_unaligned_be32(lun_data->scsi_lun) +
1407 sizeof(struct scsi_lun) > length) {
1408 length = get_unaligned_be32(lun_data->scsi_lun) +
1409 sizeof(struct scsi_lun);
1413 length = get_unaligned_be32(lun_data->scsi_lun);
1415 num_luns = (length / sizeof(struct scsi_lun));
1417 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1418 "scsi scan: REPORT LUN scan\n"));
1421 * Scan the luns in lun_data. The entry at offset 0 is really
1422 * the header, so start at 1 and go up to and including num_luns.
1424 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1425 lun = scsilun_to_int(lunp);
1427 if (lun > sdev->host->max_lun) {
1428 sdev_printk(KERN_WARNING, sdev,
1429 "lun%llu has a LUN larger than"
1430 " allowed by the host adapter\n", lun);
1434 res = scsi_probe_and_add_lun(starget,
1435 lun, NULL, NULL, rescan, NULL);
1436 if (res == SCSI_SCAN_NO_RESPONSE) {
1438 * Got some results, but now none, abort.
1440 sdev_printk(KERN_ERR, sdev,
1441 "Unexpected response"
1442 " from lun %llu while scanning, scan"
1443 " aborted\n", (unsigned long long)lun);
1452 if (scsi_device_created(sdev))
1454 * the sdev we used didn't appear in the report luns scan
1456 __scsi_remove_device(sdev);
1457 scsi_device_put(sdev);
1461 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1462 uint id, u64 lun, void *hostdata)
1464 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1465 struct device *parent = &shost->shost_gendev;
1466 struct scsi_target *starget;
1468 if (strncmp(scsi_scan_type, "none", 4) == 0)
1469 return ERR_PTR(-ENODEV);
1471 starget = scsi_alloc_target(parent, channel, id);
1473 return ERR_PTR(-ENOMEM);
1474 scsi_autopm_get_target(starget);
1476 mutex_lock(&shost->scan_mutex);
1477 if (!shost->async_scan)
1478 scsi_complete_async_scans();
1480 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1481 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1482 scsi_autopm_put_host(shost);
1484 mutex_unlock(&shost->scan_mutex);
1485 scsi_autopm_put_target(starget);
1487 * paired with scsi_alloc_target(). Target will be destroyed unless
1488 * scsi_probe_and_add_lun made an underlying device visible
1490 scsi_target_reap(starget);
1491 put_device(&starget->dev);
1495 EXPORT_SYMBOL(__scsi_add_device);
1497 int scsi_add_device(struct Scsi_Host *host, uint channel,
1498 uint target, u64 lun)
1500 struct scsi_device *sdev =
1501 __scsi_add_device(host, channel, target, lun, NULL);
1503 return PTR_ERR(sdev);
1505 scsi_device_put(sdev);
1508 EXPORT_SYMBOL(scsi_add_device);
1510 void scsi_rescan_device(struct device *dev)
1512 struct scsi_device *sdev = to_scsi_device(dev);
1516 scsi_attach_vpd(sdev);
1518 if (sdev->handler && sdev->handler->rescan)
1519 sdev->handler->rescan(sdev);
1521 if (dev->driver && try_module_get(dev->driver->owner)) {
1522 struct scsi_driver *drv = to_scsi_driver(dev->driver);
1526 module_put(dev->driver->owner);
1530 EXPORT_SYMBOL(scsi_rescan_device);
1532 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1533 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1535 struct Scsi_Host *shost = dev_to_shost(parent);
1536 blist_flags_t bflags = 0;
1538 struct scsi_target *starget;
1540 if (shost->this_id == id)
1542 * Don't scan the host adapter
1546 starget = scsi_alloc_target(parent, channel, id);
1549 scsi_autopm_get_target(starget);
1551 if (lun != SCAN_WILD_CARD) {
1553 * Scan for a specific host/chan/id/lun.
1555 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1560 * Scan LUN 0, if there is some response, scan further. Ideally, we
1561 * would not configure LUN 0 until all LUNs are scanned.
1563 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1564 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1565 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1567 * The REPORT LUN did not scan the target,
1568 * do a sequential scan.
1570 scsi_sequential_lun_scan(starget, bflags,
1571 starget->scsi_level, rescan);
1575 scsi_autopm_put_target(starget);
1577 * paired with scsi_alloc_target(): determine if the target has
1578 * any children at all and if not, nuke it
1580 scsi_target_reap(starget);
1582 put_device(&starget->dev);
1586 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1587 * @parent: host to scan
1588 * @channel: channel to scan
1589 * @id: target id to scan
1590 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1591 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for
1592 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
1593 * and SCSI_SCAN_MANUAL to force scanning even if
1594 * 'scan=manual' is set.
1597 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1598 * and possibly all LUNs on the target id.
1600 * First try a REPORT LUN scan, if that does not scan the target, do a
1601 * sequential scan of LUNs on the target id.
1603 void scsi_scan_target(struct device *parent, unsigned int channel,
1604 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1606 struct Scsi_Host *shost = dev_to_shost(parent);
1608 if (strncmp(scsi_scan_type, "none", 4) == 0)
1611 if (rescan != SCSI_SCAN_MANUAL &&
1612 strncmp(scsi_scan_type, "manual", 6) == 0)
1615 mutex_lock(&shost->scan_mutex);
1616 if (!shost->async_scan)
1617 scsi_complete_async_scans();
1619 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1620 __scsi_scan_target(parent, channel, id, lun, rescan);
1621 scsi_autopm_put_host(shost);
1623 mutex_unlock(&shost->scan_mutex);
1625 EXPORT_SYMBOL(scsi_scan_target);
1627 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1628 unsigned int id, u64 lun,
1629 enum scsi_scan_mode rescan)
1633 if (id == SCAN_WILD_CARD)
1634 for (id = 0; id < shost->max_id; ++id) {
1636 * XXX adapter drivers when possible (FCP, iSCSI)
1637 * could modify max_id to match the current max,
1638 * not the absolute max.
1640 * XXX add a shost id iterator, so for example,
1641 * the FC ID can be the same as a target id
1642 * without a huge overhead of sparse id's.
1644 if (shost->reverse_ordering)
1646 * Scan from high to low id.
1648 order_id = shost->max_id - id - 1;
1651 __scsi_scan_target(&shost->shost_gendev, channel,
1652 order_id, lun, rescan);
1655 __scsi_scan_target(&shost->shost_gendev, channel,
1659 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1660 unsigned int id, u64 lun,
1661 enum scsi_scan_mode rescan)
1663 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1664 "%s: <%u:%u:%llu>\n",
1665 __func__, channel, id, lun));
1667 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1668 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1669 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))
1672 mutex_lock(&shost->scan_mutex);
1673 if (!shost->async_scan)
1674 scsi_complete_async_scans();
1676 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1677 if (channel == SCAN_WILD_CARD)
1678 for (channel = 0; channel <= shost->max_channel;
1680 scsi_scan_channel(shost, channel, id, lun,
1683 scsi_scan_channel(shost, channel, id, lun, rescan);
1684 scsi_autopm_put_host(shost);
1686 mutex_unlock(&shost->scan_mutex);
1691 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1693 struct scsi_device *sdev;
1694 shost_for_each_device(sdev, shost) {
1695 /* target removed before the device could be added */
1696 if (sdev->sdev_state == SDEV_DEL)
1698 /* If device is already visible, skip adding it to sysfs */
1699 if (sdev->is_visible)
1701 if (!scsi_host_scan_allowed(shost) ||
1702 scsi_sysfs_add_sdev(sdev) != 0)
1703 __scsi_remove_device(sdev);
1708 * scsi_prep_async_scan - prepare for an async scan
1709 * @shost: the host which will be scanned
1710 * Returns: a cookie to be passed to scsi_finish_async_scan()
1712 * Tells the midlayer this host is going to do an asynchronous scan.
1713 * It reserves the host's position in the scanning list and ensures
1714 * that other asynchronous scans started after this one won't affect the
1715 * ordering of the discovered devices.
1717 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1719 struct async_scan_data *data = NULL;
1720 unsigned long flags;
1722 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1725 mutex_lock(&shost->scan_mutex);
1726 if (shost->async_scan) {
1727 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
1731 data = kmalloc(sizeof(*data), GFP_KERNEL);
1734 data->shost = scsi_host_get(shost);
1737 init_completion(&data->prev_finished);
1739 spin_lock_irqsave(shost->host_lock, flags);
1740 shost->async_scan = 1;
1741 spin_unlock_irqrestore(shost->host_lock, flags);
1742 mutex_unlock(&shost->scan_mutex);
1744 spin_lock(&async_scan_lock);
1745 if (list_empty(&scanning_hosts))
1746 complete(&data->prev_finished);
1747 list_add_tail(&data->list, &scanning_hosts);
1748 spin_unlock(&async_scan_lock);
1753 mutex_unlock(&shost->scan_mutex);
1759 * scsi_finish_async_scan - asynchronous scan has finished
1760 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1762 * All the devices currently attached to this host have been found.
1763 * This function announces all the devices it has found to the rest
1766 static void scsi_finish_async_scan(struct async_scan_data *data)
1768 struct Scsi_Host *shost;
1769 unsigned long flags;
1774 shost = data->shost;
1776 mutex_lock(&shost->scan_mutex);
1778 if (!shost->async_scan) {
1779 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1781 mutex_unlock(&shost->scan_mutex);
1785 wait_for_completion(&data->prev_finished);
1787 scsi_sysfs_add_devices(shost);
1789 spin_lock_irqsave(shost->host_lock, flags);
1790 shost->async_scan = 0;
1791 spin_unlock_irqrestore(shost->host_lock, flags);
1793 mutex_unlock(&shost->scan_mutex);
1795 spin_lock(&async_scan_lock);
1796 list_del(&data->list);
1797 if (!list_empty(&scanning_hosts)) {
1798 struct async_scan_data *next = list_entry(scanning_hosts.next,
1799 struct async_scan_data, list);
1800 complete(&next->prev_finished);
1802 spin_unlock(&async_scan_lock);
1804 scsi_autopm_put_host(shost);
1805 scsi_host_put(shost);
1809 static void do_scsi_scan_host(struct Scsi_Host *shost)
1811 if (shost->hostt->scan_finished) {
1812 unsigned long start = jiffies;
1813 if (shost->hostt->scan_start)
1814 shost->hostt->scan_start(shost);
1816 while (!shost->hostt->scan_finished(shost, jiffies - start))
1819 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1824 static void do_scan_async(void *_data, async_cookie_t c)
1826 struct async_scan_data *data = _data;
1827 struct Scsi_Host *shost = data->shost;
1829 do_scsi_scan_host(shost);
1830 scsi_finish_async_scan(data);
1834 * scsi_scan_host - scan the given adapter
1835 * @shost: adapter to scan
1837 void scsi_scan_host(struct Scsi_Host *shost)
1839 struct async_scan_data *data;
1841 if (strncmp(scsi_scan_type, "none", 4) == 0 ||
1842 strncmp(scsi_scan_type, "manual", 6) == 0)
1844 if (scsi_autopm_get_host(shost) < 0)
1847 data = scsi_prep_async_scan(shost);
1849 do_scsi_scan_host(shost);
1850 scsi_autopm_put_host(shost);
1854 /* register with the async subsystem so wait_for_device_probe()
1855 * will flush this work
1857 async_schedule(do_scan_async, data);
1859 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1861 EXPORT_SYMBOL(scsi_scan_host);
1863 void scsi_forget_host(struct Scsi_Host *shost)
1865 struct scsi_device *sdev;
1866 unsigned long flags;
1869 spin_lock_irqsave(shost->host_lock, flags);
1870 list_for_each_entry(sdev, &shost->__devices, siblings) {
1871 if (sdev->sdev_state == SDEV_DEL)
1873 spin_unlock_irqrestore(shost->host_lock, flags);
1874 __scsi_remove_device(sdev);
1877 spin_unlock_irqrestore(shost->host_lock, flags);
1881 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
1882 * @shost: Host that needs a scsi_device
1884 * Lock status: None assumed.
1886 * Returns: The scsi_device or NULL
1889 * Attach a single scsi_device to the Scsi_Host - this should
1890 * be made to look like a "pseudo-device" that points to the
1893 * Note - this device is not accessible from any high-level
1894 * drivers (including generics), which is probably not
1895 * optimal. We can add hooks later to attach.
1897 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1899 struct scsi_device *sdev = NULL;
1900 struct scsi_target *starget;
1902 mutex_lock(&shost->scan_mutex);
1903 if (!scsi_host_scan_allowed(shost))
1905 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1909 sdev = scsi_alloc_sdev(starget, 0, NULL);
1913 scsi_target_reap(starget);
1914 put_device(&starget->dev);
1916 mutex_unlock(&shost->scan_mutex);
1919 EXPORT_SYMBOL(scsi_get_host_dev);
1922 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
1923 * @sdev: Host device to be freed
1925 * Lock status: None assumed.
1929 void scsi_free_host_dev(struct scsi_device *sdev)
1931 BUG_ON(sdev->id != sdev->host->this_id);
1933 __scsi_remove_device(sdev);
1935 EXPORT_SYMBOL(scsi_free_host_dev);