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 static 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_enable_async_suspend - Enable async suspend and resume
128 void scsi_enable_async_suspend(struct device
*dev
)
131 * If a user has disabled async probing a likely reason is due to a
132 * storage enclosure that does not inject staggered spin-ups. For
133 * safety, make resume synchronous as well in that case.
135 if (strncmp(scsi_scan_type
, "async", 5) != 0)
137 /* Enable asynchronous suspend and resume. */
138 device_enable_async_suspend(dev
);
142 * scsi_complete_async_scans - Wait for asynchronous scans to complete
144 * When this function returns, any host which started scanning before
145 * this function was called will have finished its scan. Hosts which
146 * started scanning after this function was called may or may not have
149 int scsi_complete_async_scans(void)
151 struct async_scan_data
*data
;
154 if (list_empty(&scanning_hosts
))
156 /* If we can't get memory immediately, that's OK. Just
157 * sleep a little. Even if we never get memory, the async
158 * scans will finish eventually.
160 data
= kmalloc(sizeof(*data
), GFP_KERNEL
);
166 init_completion(&data
->prev_finished
);
168 spin_lock(&async_scan_lock
);
169 /* Check that there's still somebody else on the list */
170 if (list_empty(&scanning_hosts
))
172 list_add_tail(&data
->list
, &scanning_hosts
);
173 spin_unlock(&async_scan_lock
);
175 printk(KERN_INFO
"scsi: waiting for bus probes to complete ...\n");
176 wait_for_completion(&data
->prev_finished
);
178 spin_lock(&async_scan_lock
);
179 list_del(&data
->list
);
180 if (!list_empty(&scanning_hosts
)) {
181 struct async_scan_data
*next
= list_entry(scanning_hosts
.next
,
182 struct async_scan_data
, list
);
183 complete(&next
->prev_finished
);
186 spin_unlock(&async_scan_lock
);
193 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
194 * @sdev: scsi device to send command to
195 * @result: area to store the result of the MODE SENSE
198 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
199 * Called for BLIST_KEY devices.
201 static void scsi_unlock_floptical(struct scsi_device
*sdev
,
202 unsigned char *result
)
204 unsigned char scsi_cmd
[MAX_COMMAND_SIZE
];
206 sdev_printk(KERN_NOTICE
, sdev
, "unlocking floptical drive\n");
207 scsi_cmd
[0] = MODE_SENSE
;
211 scsi_cmd
[4] = 0x2a; /* size */
213 scsi_execute_cmd(sdev
, scsi_cmd
, REQ_OP_DRV_IN
, result
, 0x2a,
214 SCSI_TIMEOUT
, 3, NULL
);
217 static int scsi_realloc_sdev_budget_map(struct scsi_device
*sdev
,
220 int new_shift
= sbitmap_calculate_shift(depth
);
221 bool need_alloc
= !sdev
->budget_map
.map
;
222 bool need_free
= false;
224 struct sbitmap sb_backup
;
226 depth
= min_t(unsigned int, depth
, scsi_device_max_queue_depth(sdev
));
229 * realloc if new shift is calculated, which is caused by setting
230 * up one new default queue depth after calling ->slave_configure
232 if (!need_alloc
&& new_shift
!= sdev
->budget_map
.shift
)
233 need_alloc
= need_free
= true;
239 * Request queue has to be frozen for reallocating budget map,
240 * and here disk isn't added yet, so freezing is pretty fast
243 blk_mq_freeze_queue(sdev
->request_queue
);
244 sb_backup
= sdev
->budget_map
;
246 ret
= sbitmap_init_node(&sdev
->budget_map
,
247 scsi_device_max_queue_depth(sdev
),
248 new_shift
, GFP_KERNEL
,
249 sdev
->request_queue
->node
, false, true);
251 sbitmap_resize(&sdev
->budget_map
, depth
);
255 sdev
->budget_map
= sb_backup
;
257 sbitmap_free(&sb_backup
);
259 blk_mq_unfreeze_queue(sdev
->request_queue
);
265 * scsi_alloc_sdev - allocate and setup a scsi_Device
266 * @starget: which target to allocate a &scsi_device for
268 * @hostdata: usually NULL and set by ->slave_alloc instead
271 * Allocate, initialize for io, and return a pointer to a scsi_Device.
272 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
273 * adds scsi_Device to the appropriate list.
276 * scsi_Device pointer, or NULL on failure.
278 static struct scsi_device
*scsi_alloc_sdev(struct scsi_target
*starget
,
279 u64 lun
, void *hostdata
)
282 struct scsi_device
*sdev
;
283 struct request_queue
*q
;
284 int display_failure_msg
= 1, ret
;
285 struct Scsi_Host
*shost
= dev_to_shost(starget
->dev
.parent
);
287 sdev
= kzalloc(sizeof(*sdev
) + shost
->transportt
->device_size
,
292 sdev
->vendor
= scsi_null_device_strs
;
293 sdev
->model
= scsi_null_device_strs
;
294 sdev
->rev
= scsi_null_device_strs
;
296 sdev
->queue_ramp_up_period
= SCSI_DEFAULT_RAMP_UP_PERIOD
;
297 sdev
->id
= starget
->id
;
299 sdev
->channel
= starget
->channel
;
300 mutex_init(&sdev
->state_mutex
);
301 sdev
->sdev_state
= SDEV_CREATED
;
302 INIT_LIST_HEAD(&sdev
->siblings
);
303 INIT_LIST_HEAD(&sdev
->same_target_siblings
);
304 INIT_LIST_HEAD(&sdev
->starved_entry
);
305 INIT_LIST_HEAD(&sdev
->event_list
);
306 spin_lock_init(&sdev
->list_lock
);
307 mutex_init(&sdev
->inquiry_mutex
);
308 INIT_WORK(&sdev
->event_work
, scsi_evt_thread
);
309 INIT_WORK(&sdev
->requeue_work
, scsi_requeue_run_queue
);
311 sdev
->sdev_gendev
.parent
= get_device(&starget
->dev
);
312 sdev
->sdev_target
= starget
;
314 /* usually NULL and set by ->slave_alloc instead */
315 sdev
->hostdata
= hostdata
;
317 /* if the device needs this changing, it may do so in the
318 * slave_configure function */
319 sdev
->max_device_blocked
= SCSI_DEFAULT_DEVICE_BLOCKED
;
322 * Some low level driver could use device->type
327 * Assume that the device will have handshaking problems,
328 * and then fix this field later if it turns out it
333 sdev
->sg_reserved_size
= INT_MAX
;
335 q
= blk_mq_alloc_queue(&sdev
->host
->tag_set
, NULL
, NULL
);
337 /* release fn is set up in scsi_sysfs_device_initialise, so
338 * have to free and put manually here */
339 put_device(&starget
->dev
);
343 kref_get(&sdev
->host
->tagset_refcnt
);
344 sdev
->request_queue
= q
;
346 __scsi_init_queue(sdev
->host
, q
);
348 depth
= sdev
->host
->cmd_per_lun
?: 1;
351 * Use .can_queue as budget map's depth because we have to
352 * support adjusting queue depth from sysfs. Meantime use
353 * default device queue depth to figure out sbitmap shift
354 * since we use this queue depth most of times.
356 if (scsi_realloc_sdev_budget_map(sdev
, depth
)) {
357 put_device(&starget
->dev
);
362 scsi_change_queue_depth(sdev
, depth
);
364 scsi_sysfs_device_initialize(sdev
);
366 if (shost
->hostt
->slave_alloc
) {
367 ret
= shost
->hostt
->slave_alloc(sdev
);
370 * if LLDD reports slave not present, don't clutter
371 * console with alloc failure messages
374 display_failure_msg
= 0;
375 goto out_device_destroy
;
382 __scsi_remove_device(sdev
);
384 if (display_failure_msg
)
385 printk(ALLOC_FAILURE_MSG
, __func__
);
389 static void scsi_target_destroy(struct scsi_target
*starget
)
391 struct device
*dev
= &starget
->dev
;
392 struct Scsi_Host
*shost
= dev_to_shost(dev
->parent
);
395 BUG_ON(starget
->state
== STARGET_DEL
);
396 starget
->state
= STARGET_DEL
;
397 transport_destroy_device(dev
);
398 spin_lock_irqsave(shost
->host_lock
, flags
);
399 if (shost
->hostt
->target_destroy
)
400 shost
->hostt
->target_destroy(starget
);
401 list_del_init(&starget
->siblings
);
402 spin_unlock_irqrestore(shost
->host_lock
, flags
);
406 static void scsi_target_dev_release(struct device
*dev
)
408 struct device
*parent
= dev
->parent
;
409 struct scsi_target
*starget
= to_scsi_target(dev
);
415 static struct device_type scsi_target_type
= {
416 .name
= "scsi_target",
417 .release
= scsi_target_dev_release
,
420 int scsi_is_target_device(const struct device
*dev
)
422 return dev
->type
== &scsi_target_type
;
424 EXPORT_SYMBOL(scsi_is_target_device
);
426 static struct scsi_target
*__scsi_find_target(struct device
*parent
,
427 int channel
, uint id
)
429 struct scsi_target
*starget
, *found_starget
= NULL
;
430 struct Scsi_Host
*shost
= dev_to_shost(parent
);
432 * Search for an existing target for this sdev.
434 list_for_each_entry(starget
, &shost
->__targets
, siblings
) {
435 if (starget
->id
== id
&&
436 starget
->channel
== channel
) {
437 found_starget
= starget
;
442 get_device(&found_starget
->dev
);
444 return found_starget
;
448 * scsi_target_reap_ref_release - remove target from visibility
449 * @kref: the reap_ref in the target being released
451 * Called on last put of reap_ref, which is the indication that no device
452 * under this target is visible anymore, so render the target invisible in
453 * sysfs. Note: we have to be in user context here because the target reaps
454 * should be done in places where the scsi device visibility is being removed.
456 static void scsi_target_reap_ref_release(struct kref
*kref
)
458 struct scsi_target
*starget
459 = container_of(kref
, struct scsi_target
, reap_ref
);
462 * if we get here and the target is still in a CREATED state that
463 * means it was allocated but never made visible (because a scan
464 * turned up no LUNs), so don't call device_del() on it.
466 if ((starget
->state
!= STARGET_CREATED
) &&
467 (starget
->state
!= STARGET_CREATED_REMOVE
)) {
468 transport_remove_device(&starget
->dev
);
469 device_del(&starget
->dev
);
471 scsi_target_destroy(starget
);
474 static void scsi_target_reap_ref_put(struct scsi_target
*starget
)
476 kref_put(&starget
->reap_ref
, scsi_target_reap_ref_release
);
480 * scsi_alloc_target - allocate a new or find an existing target
481 * @parent: parent of the target (need not be a scsi host)
482 * @channel: target channel number (zero if no channels)
483 * @id: target id number
485 * Return an existing target if one exists, provided it hasn't already
486 * gone into STARGET_DEL state, otherwise allocate a new target.
488 * The target is returned with an incremented reference, so the caller
489 * is responsible for both reaping and doing a last put
491 static struct scsi_target
*scsi_alloc_target(struct device
*parent
,
492 int channel
, uint id
)
494 struct Scsi_Host
*shost
= dev_to_shost(parent
);
495 struct device
*dev
= NULL
;
497 const int size
= sizeof(struct scsi_target
)
498 + shost
->transportt
->target_size
;
499 struct scsi_target
*starget
;
500 struct scsi_target
*found_target
;
503 starget
= kzalloc(size
, GFP_KERNEL
);
505 printk(KERN_ERR
"%s: allocation failure\n", __func__
);
509 device_initialize(dev
);
510 kref_init(&starget
->reap_ref
);
511 dev
->parent
= get_device(parent
);
512 dev_set_name(dev
, "target%d:%d:%d", shost
->host_no
, channel
, id
);
513 dev
->bus
= &scsi_bus_type
;
514 dev
->type
= &scsi_target_type
;
515 scsi_enable_async_suspend(dev
);
517 starget
->channel
= channel
;
518 starget
->can_queue
= 0;
519 INIT_LIST_HEAD(&starget
->siblings
);
520 INIT_LIST_HEAD(&starget
->devices
);
521 starget
->state
= STARGET_CREATED
;
522 starget
->scsi_level
= SCSI_2
;
523 starget
->max_target_blocked
= SCSI_DEFAULT_TARGET_BLOCKED
;
525 spin_lock_irqsave(shost
->host_lock
, flags
);
527 found_target
= __scsi_find_target(parent
, channel
, id
);
531 list_add_tail(&starget
->siblings
, &shost
->__targets
);
532 spin_unlock_irqrestore(shost
->host_lock
, flags
);
533 /* allocate and add */
534 transport_setup_device(dev
);
535 if (shost
->hostt
->target_alloc
) {
536 error
= shost
->hostt
->target_alloc(starget
);
540 dev_err(dev
, "target allocation failed, error %d\n", error
);
541 /* don't want scsi_target_reap to do the final
542 * put because it will be under the host lock */
543 scsi_target_destroy(starget
);
553 * release routine already fired if kref is zero, so if we can still
554 * take the reference, the target must be alive. If we can't, it must
555 * be dying and we need to wait for a new target
557 ref_got
= kref_get_unless_zero(&found_target
->reap_ref
);
559 spin_unlock_irqrestore(shost
->host_lock
, flags
);
565 * Unfortunately, we found a dying target; need to wait until it's
566 * dead before we can get a new one. There is an anomaly here. We
567 * *should* call scsi_target_reap() to balance the kref_get() of the
568 * reap_ref above. However, since the target being released, it's
569 * already invisible and the reap_ref is irrelevant. If we call
570 * scsi_target_reap() we might spuriously do another device_del() on
571 * an already invisible target.
573 put_device(&found_target
->dev
);
575 * length of time is irrelevant here, we just want to yield the CPU
576 * for a tick to avoid busy waiting for the target to die.
583 * scsi_target_reap - check to see if target is in use and destroy if not
584 * @starget: target to be checked
586 * This is used after removing a LUN or doing a last put of the target
587 * it checks atomically that nothing is using the target and removes
590 void scsi_target_reap(struct scsi_target
*starget
)
593 * serious problem if this triggers: STARGET_DEL is only set in the if
594 * the reap_ref drops to zero, so we're trying to do another final put
595 * on an already released kref
597 BUG_ON(starget
->state
== STARGET_DEL
);
598 scsi_target_reap_ref_put(starget
);
602 * scsi_sanitize_inquiry_string - remove non-graphical chars from an
603 * INQUIRY result string
604 * @s: INQUIRY result string to sanitize
605 * @len: length of the string
608 * The SCSI spec says that INQUIRY vendor, product, and revision
609 * strings must consist entirely of graphic ASCII characters,
610 * padded on the right with spaces. Since not all devices obey
611 * this rule, we will replace non-graphic or non-ASCII characters
612 * with spaces. Exception: a NUL character is interpreted as a
613 * string terminator, so all the following characters are set to
616 void scsi_sanitize_inquiry_string(unsigned char *s
, int len
)
620 for (; len
> 0; (--len
, ++s
)) {
623 if (terminated
|| *s
< 0x20 || *s
> 0x7e)
627 EXPORT_SYMBOL(scsi_sanitize_inquiry_string
);
630 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
631 * @sdev: scsi_device to probe
632 * @inq_result: area to store the INQUIRY result
633 * @result_len: len of inq_result
634 * @bflags: store any bflags found here
637 * Probe the lun associated with @req using a standard SCSI INQUIRY;
639 * If the INQUIRY is successful, zero is returned and the
640 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
641 * are copied to the scsi_device any flags value is stored in *@bflags.
643 static int scsi_probe_lun(struct scsi_device
*sdev
, unsigned char *inq_result
,
644 int result_len
, blist_flags_t
*bflags
)
646 unsigned char scsi_cmd
[MAX_COMMAND_SIZE
];
647 int first_inquiry_len
, try_inquiry_len
, next_inquiry_len
;
648 int response_len
= 0;
649 int pass
, count
, result
, resid
;
650 struct scsi_sense_hdr sshdr
;
651 const struct scsi_exec_args exec_args
= {
658 /* Perform up to 3 passes. The first pass uses a conservative
659 * transfer length of 36 unless sdev->inquiry_len specifies a
660 * different value. */
661 first_inquiry_len
= sdev
->inquiry_len
? sdev
->inquiry_len
: 36;
662 try_inquiry_len
= first_inquiry_len
;
666 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO
, sdev
,
667 "scsi scan: INQUIRY pass %d length %d\n",
668 pass
, try_inquiry_len
));
670 /* Each pass gets up to three chances to ignore Unit Attention */
671 for (count
= 0; count
< 3; ++count
) {
672 memset(scsi_cmd
, 0, 6);
673 scsi_cmd
[0] = INQUIRY
;
674 scsi_cmd
[4] = (unsigned char) try_inquiry_len
;
676 memset(inq_result
, 0, try_inquiry_len
);
678 result
= scsi_execute_cmd(sdev
, scsi_cmd
, REQ_OP_DRV_IN
,
679 inq_result
, try_inquiry_len
,
680 HZ
/ 2 + HZ
* scsi_inq_timeout
, 3,
683 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO
, sdev
,
684 "scsi scan: INQUIRY %s with code 0x%x\n",
685 result
? "failed" : "successful", result
));
689 * not-ready to ready transition [asc/ascq=0x28/0x0]
690 * or power-on, reset [asc/ascq=0x29/0x0], continue.
691 * INQUIRY should not yield UNIT_ATTENTION
692 * but many buggy devices do so anyway.
694 if (scsi_status_is_check_condition(result
) &&
695 scsi_sense_valid(&sshdr
)) {
696 if ((sshdr
.sense_key
== UNIT_ATTENTION
) &&
697 ((sshdr
.asc
== 0x28) ||
698 (sshdr
.asc
== 0x29)) &&
702 } else if (result
== 0) {
704 * if nothing was transferred, we try
705 * again. It's a workaround for some USB
708 if (resid
== try_inquiry_len
)
715 scsi_sanitize_inquiry_string(&inq_result
[8], 8);
716 scsi_sanitize_inquiry_string(&inq_result
[16], 16);
717 scsi_sanitize_inquiry_string(&inq_result
[32], 4);
719 response_len
= inq_result
[4] + 5;
720 if (response_len
> 255)
721 response_len
= first_inquiry_len
; /* sanity */
724 * Get any flags for this device.
726 * XXX add a bflags to scsi_device, and replace the
727 * corresponding bit fields in scsi_device, so bflags
728 * need not be passed as an argument.
730 *bflags
= scsi_get_device_flags(sdev
, &inq_result
[8],
733 /* When the first pass succeeds we gain information about
734 * what larger transfer lengths might work. */
736 if (BLIST_INQUIRY_36
& *bflags
)
737 next_inquiry_len
= 36;
739 * LLD specified a maximum sdev->inquiry_len
740 * but device claims it has more data. Capping
741 * the length only makes sense for legacy
742 * devices. If a device supports SPC-4 (2014)
743 * or newer, assume that it is safe to ask for
744 * as much as the device says it supports.
746 else if (sdev
->inquiry_len
&&
747 response_len
> sdev
->inquiry_len
&&
748 (inq_result
[2] & 0x7) < 6) /* SPC-4 */
749 next_inquiry_len
= sdev
->inquiry_len
;
751 next_inquiry_len
= response_len
;
753 /* If more data is available perform the second pass */
754 if (next_inquiry_len
> try_inquiry_len
) {
755 try_inquiry_len
= next_inquiry_len
;
761 } else if (pass
== 2) {
762 sdev_printk(KERN_INFO
, sdev
,
763 "scsi scan: %d byte inquiry failed. "
764 "Consider BLIST_INQUIRY_36 for this device\n",
767 /* If this pass failed, the third pass goes back and transfers
768 * the same amount as we successfully got in the first pass. */
769 try_inquiry_len
= first_inquiry_len
;
774 /* If the last transfer attempt got an error, assume the
775 * peripheral doesn't exist or is dead. */
779 /* Don't report any more data than the device says is valid */
780 sdev
->inquiry_len
= min(try_inquiry_len
, response_len
);
783 * XXX Abort if the response length is less than 36? If less than
784 * 32, the lookup of the device flags (above) could be invalid,
785 * and it would be possible to take an incorrect action - we do
786 * not want to hang because of a short INQUIRY. On the flip side,
787 * if the device is spun down or becoming ready (and so it gives a
788 * short INQUIRY), an abort here prevents any further use of the
789 * device, including spin up.
791 * On the whole, the best approach seems to be to assume the first
792 * 36 bytes are valid no matter what the device says. That's
793 * better than copying < 36 bytes to the inquiry-result buffer
794 * and displaying garbage for the Vendor, Product, or Revision
797 if (sdev
->inquiry_len
< 36) {
798 if (!sdev
->host
->short_inquiry
) {
799 shost_printk(KERN_INFO
, sdev
->host
,
800 "scsi scan: INQUIRY result too short (%d),"
801 " using 36\n", sdev
->inquiry_len
);
802 sdev
->host
->short_inquiry
= 1;
804 sdev
->inquiry_len
= 36;
808 * Related to the above issue:
810 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
811 * and if not ready, sent a START_STOP to start (maybe spin up) and
812 * then send the INQUIRY again, since the INQUIRY can change after
813 * a device is initialized.
815 * Ideally, start a device if explicitly asked to do so. This
816 * assumes that a device is spun up on power on, spun down on
817 * request, and then spun up on request.
821 * The scanning code needs to know the scsi_level, even if no
822 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
823 * non-zero LUNs can be scanned.
825 sdev
->scsi_level
= inq_result
[2] & 0x0f;
826 if (sdev
->scsi_level
>= 2 ||
827 (sdev
->scsi_level
== 1 && (inq_result
[3] & 0x0f) == 1))
829 sdev
->sdev_target
->scsi_level
= sdev
->scsi_level
;
832 * If SCSI-2 or lower, and if the transport requires it,
833 * store the LUN value in CDB[1].
835 sdev
->lun_in_cdb
= 0;
836 if (sdev
->scsi_level
<= SCSI_2
&&
837 sdev
->scsi_level
!= SCSI_UNKNOWN
&&
838 !sdev
->host
->no_scsi2_lun_in_cdb
)
839 sdev
->lun_in_cdb
= 1;
845 * scsi_add_lun - allocate and fully initialze a scsi_device
846 * @sdev: holds information to be stored in the new scsi_device
847 * @inq_result: holds the result of a previous INQUIRY to the LUN
848 * @bflags: black/white list flag
849 * @async: 1 if this device is being scanned asynchronously
852 * Initialize the scsi_device @sdev. Optionally set fields based
853 * on values in *@bflags.
856 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
857 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
859 static int scsi_add_lun(struct scsi_device
*sdev
, unsigned char *inq_result
,
860 blist_flags_t
*bflags
, int async
)
865 * XXX do not save the inquiry, since it can change underneath us,
866 * save just vendor/model/rev.
868 * Rather than save it and have an ioctl that retrieves the saved
869 * value, have an ioctl that executes the same INQUIRY code used
870 * in scsi_probe_lun, let user level programs doing INQUIRY
871 * scanning run at their own risk, or supply a user level program
872 * that can correctly scan.
876 * Copy at least 36 bytes of INQUIRY data, so that we don't
877 * dereference unallocated memory when accessing the Vendor,
878 * Product, and Revision strings. Badly behaved devices may set
879 * the INQUIRY Additional Length byte to a small value, indicating
880 * these strings are invalid, but often they contain plausible data
881 * nonetheless. It doesn't matter if the device sent < 36 bytes
882 * total, since scsi_probe_lun() initializes inq_result with 0s.
884 sdev
->inquiry
= kmemdup(inq_result
,
885 max_t(size_t, sdev
->inquiry_len
, 36),
887 if (sdev
->inquiry
== NULL
)
888 return SCSI_SCAN_NO_RESPONSE
;
890 sdev
->vendor
= (char *) (sdev
->inquiry
+ 8);
891 sdev
->model
= (char *) (sdev
->inquiry
+ 16);
892 sdev
->rev
= (char *) (sdev
->inquiry
+ 32);
894 if (strncmp(sdev
->vendor
, "ATA ", 8) == 0) {
896 * sata emulation layer device. This is a hack to work around
897 * the SATL power management specifications which state that
898 * when the SATL detects the device has gone into standby
899 * mode, it shall respond with NOT READY.
901 sdev
->allow_restart
= 1;
904 if (*bflags
& BLIST_ISROM
) {
905 sdev
->type
= TYPE_ROM
;
908 sdev
->type
= (inq_result
[0] & 0x1f);
909 sdev
->removable
= (inq_result
[1] & 0x80) >> 7;
912 * some devices may respond with wrong type for
913 * well-known logical units. Force well-known type
914 * to enumerate them correctly.
916 if (scsi_is_wlun(sdev
->lun
) && sdev
->type
!= TYPE_WLUN
) {
917 sdev_printk(KERN_WARNING
, sdev
,
918 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
919 __func__
, sdev
->type
, (unsigned int)sdev
->lun
);
920 sdev
->type
= TYPE_WLUN
;
925 if (sdev
->type
== TYPE_RBC
|| sdev
->type
== TYPE_ROM
) {
926 /* RBC and MMC devices can return SCSI-3 compliance and yet
927 * still not support REPORT LUNS, so make them act as
928 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
929 * specifically set */
930 if ((*bflags
& BLIST_REPORTLUN2
) == 0)
931 *bflags
|= BLIST_NOREPORTLUN
;
935 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
936 * spec says: The device server is capable of supporting the
937 * specified peripheral device type on this logical unit. However,
938 * the physical device is not currently connected to this logical
941 * The above is vague, as it implies that we could treat 001 and
942 * 011 the same. Stay compatible with previous code, and create a
943 * scsi_device for a PQ of 1
945 * Don't set the device offline here; rather let the upper
946 * level drivers eval the PQ to decide whether they should
947 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
950 sdev
->inq_periph_qual
= (inq_result
[0] >> 5) & 7;
951 sdev
->lockable
= sdev
->removable
;
952 sdev
->soft_reset
= (inq_result
[7] & 1) && ((inq_result
[3] & 7) == 2);
954 if (sdev
->scsi_level
>= SCSI_3
||
955 (sdev
->inquiry_len
> 56 && inq_result
[56] & 0x04))
957 if (inq_result
[7] & 0x60)
959 if (inq_result
[7] & 0x10)
962 sdev_printk(KERN_NOTICE
, sdev
, "%s %.8s %.16s %.4s PQ: %d "
963 "ANSI: %d%s\n", scsi_device_type(sdev
->type
),
964 sdev
->vendor
, sdev
->model
, sdev
->rev
,
965 sdev
->inq_periph_qual
, inq_result
[2] & 0x07,
966 (inq_result
[3] & 0x0f) == 1 ? " CCS" : "");
968 if ((sdev
->scsi_level
>= SCSI_2
) && (inq_result
[7] & 2) &&
969 !(*bflags
& BLIST_NOTQ
)) {
970 sdev
->tagged_supported
= 1;
971 sdev
->simple_tags
= 1;
975 * Some devices (Texel CD ROM drives) have handshaking problems
976 * when used with the Seagate controllers. borken is initialized
977 * to 1, and then set it to 0 here.
979 if ((*bflags
& BLIST_BORKEN
) == 0)
982 if (*bflags
& BLIST_NO_ULD_ATTACH
)
983 sdev
->no_uld_attach
= 1;
986 * Apparently some really broken devices (contrary to the SCSI
987 * standards) need to be selected without asserting ATN
989 if (*bflags
& BLIST_SELECT_NO_ATN
)
990 sdev
->select_no_atn
= 1;
993 * Maximum 512 sector transfer length
994 * broken RA4x00 Compaq Disk Array
996 if (*bflags
& BLIST_MAX_512
)
997 blk_queue_max_hw_sectors(sdev
->request_queue
, 512);
999 * Max 1024 sector transfer length for targets that report incorrect
1000 * max/optimal lengths and relied on the old block layer safe default
1002 else if (*bflags
& BLIST_MAX_1024
)
1003 blk_queue_max_hw_sectors(sdev
->request_queue
, 1024);
1006 * Some devices may not want to have a start command automatically
1007 * issued when a device is added.
1009 if (*bflags
& BLIST_NOSTARTONADD
)
1010 sdev
->no_start_on_add
= 1;
1012 if (*bflags
& BLIST_SINGLELUN
)
1013 scsi_target(sdev
)->single_lun
= 1;
1015 sdev
->use_10_for_rw
= 1;
1017 /* some devices don't like REPORT SUPPORTED OPERATION CODES
1018 * and will simply timeout causing sd_mod init to take a very
1020 if (*bflags
& BLIST_NO_RSOC
)
1021 sdev
->no_report_opcodes
= 1;
1023 /* set the device running here so that slave configure
1025 mutex_lock(&sdev
->state_mutex
);
1026 ret
= scsi_device_set_state(sdev
, SDEV_RUNNING
);
1028 ret
= scsi_device_set_state(sdev
, SDEV_BLOCK
);
1029 mutex_unlock(&sdev
->state_mutex
);
1032 sdev_printk(KERN_ERR
, sdev
,
1033 "in wrong state %s to complete scan\n",
1034 scsi_device_state_name(sdev
->sdev_state
));
1035 return SCSI_SCAN_NO_RESPONSE
;
1038 if (*bflags
& BLIST_NOT_LOCKABLE
)
1041 if (*bflags
& BLIST_RETRY_HWERROR
)
1042 sdev
->retry_hwerror
= 1;
1044 if (*bflags
& BLIST_NO_DIF
)
1047 if (*bflags
& BLIST_UNMAP_LIMIT_WS
)
1048 sdev
->unmap_limit_for_ws
= 1;
1050 if (*bflags
& BLIST_IGN_MEDIA_CHANGE
)
1051 sdev
->ignore_media_change
= 1;
1053 sdev
->eh_timeout
= SCSI_DEFAULT_EH_TIMEOUT
;
1055 if (*bflags
& BLIST_TRY_VPD_PAGES
)
1056 sdev
->try_vpd_pages
= 1;
1057 else if (*bflags
& BLIST_SKIP_VPD_PAGES
)
1058 sdev
->skip_vpd_pages
= 1;
1060 if (*bflags
& BLIST_NO_VPD_SIZE
)
1061 sdev
->no_vpd_size
= 1;
1063 transport_configure_device(&sdev
->sdev_gendev
);
1065 if (sdev
->host
->hostt
->slave_configure
) {
1066 ret
= sdev
->host
->hostt
->slave_configure(sdev
);
1069 * if LLDD reports slave not present, don't clutter
1070 * console with alloc failure messages
1072 if (ret
!= -ENXIO
) {
1073 sdev_printk(KERN_ERR
, sdev
,
1074 "failed to configure device\n");
1076 return SCSI_SCAN_NO_RESPONSE
;
1080 * The queue_depth is often changed in ->slave_configure.
1081 * Set up budget map again since memory consumption of
1082 * the map depends on actual queue depth.
1084 scsi_realloc_sdev_budget_map(sdev
, sdev
->queue_depth
);
1087 if (sdev
->scsi_level
>= SCSI_3
)
1088 scsi_attach_vpd(sdev
);
1090 scsi_cdl_check(sdev
);
1092 sdev
->max_queue_depth
= sdev
->queue_depth
;
1093 WARN_ON_ONCE(sdev
->max_queue_depth
> sdev
->budget_map
.depth
);
1094 sdev
->sdev_bflags
= *bflags
;
1097 * Ok, the device is now all set up, we can
1098 * register it and tell the rest of the kernel
1101 if (!async
&& scsi_sysfs_add_sdev(sdev
) != 0)
1102 return SCSI_SCAN_NO_RESPONSE
;
1104 return SCSI_SCAN_LUN_PRESENT
;
1107 #ifdef CONFIG_SCSI_LOGGING
1109 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
1110 * @buf: Output buffer with at least end-first+1 bytes of space
1111 * @inq: Inquiry buffer (input)
1112 * @first: Offset of string into inq
1113 * @end: Index after last character in inq
1115 static unsigned char *scsi_inq_str(unsigned char *buf
, unsigned char *inq
,
1116 unsigned first
, unsigned end
)
1118 unsigned term
= 0, idx
;
1120 for (idx
= 0; idx
+ first
< end
&& idx
+ first
< inq
[4] + 5; idx
++) {
1121 if (inq
[idx
+first
] > ' ') {
1122 buf
[idx
] = inq
[idx
+first
];
1134 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1135 * @starget: pointer to target device structure
1136 * @lun: LUN of target device
1137 * @bflagsp: store bflags here if not NULL
1138 * @sdevp: probe the LUN corresponding to this scsi_device
1139 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only
1140 * needed on first scan
1141 * @hostdata: passed to scsi_alloc_sdev()
1144 * Call scsi_probe_lun, if a LUN with an attached device is found,
1145 * allocate and set it up by calling scsi_add_lun.
1149 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1150 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1151 * attached at the LUN
1152 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1154 static int scsi_probe_and_add_lun(struct scsi_target
*starget
,
1155 u64 lun
, blist_flags_t
*bflagsp
,
1156 struct scsi_device
**sdevp
,
1157 enum scsi_scan_mode rescan
,
1160 struct scsi_device
*sdev
;
1161 unsigned char *result
;
1162 blist_flags_t bflags
;
1163 int res
= SCSI_SCAN_NO_RESPONSE
, result_len
= 256;
1164 struct Scsi_Host
*shost
= dev_to_shost(starget
->dev
.parent
);
1167 * The rescan flag is used as an optimization, the first scan of a
1168 * host adapter calls into here with rescan == 0.
1170 sdev
= scsi_device_lookup_by_target(starget
, lun
);
1172 if (rescan
!= SCSI_SCAN_INITIAL
|| !scsi_device_created(sdev
)) {
1173 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO
, sdev
,
1174 "scsi scan: device exists on %s\n",
1175 dev_name(&sdev
->sdev_gendev
)));
1179 scsi_device_put(sdev
);
1182 *bflagsp
= scsi_get_device_flags(sdev
,
1185 return SCSI_SCAN_LUN_PRESENT
;
1187 scsi_device_put(sdev
);
1189 sdev
= scsi_alloc_sdev(starget
, lun
, hostdata
);
1193 result
= kmalloc(result_len
, GFP_KERNEL
);
1197 if (scsi_probe_lun(sdev
, result
, result_len
, &bflags
))
1198 goto out_free_result
;
1203 * result contains valid SCSI INQUIRY data.
1205 if ((result
[0] >> 5) == 3) {
1207 * For a Peripheral qualifier 3 (011b), the SCSI
1208 * spec says: The device server is not capable of
1209 * supporting a physical device on this logical
1212 * For disks, this implies that there is no
1213 * logical disk configured at sdev->lun, but there
1214 * is a target id responding.
1216 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO
, sdev
, "scsi scan:"
1217 " peripheral qualifier of 3, device not"
1220 SCSI_LOG_SCAN_BUS(1, {
1221 unsigned char vend
[9];
1222 unsigned char mod
[17];
1224 sdev_printk(KERN_INFO
, sdev
,
1225 "scsi scan: consider passing scsi_mod."
1226 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1227 scsi_inq_str(vend
, result
, 8, 16),
1228 scsi_inq_str(mod
, result
, 16, 32));
1233 res
= SCSI_SCAN_TARGET_PRESENT
;
1234 goto out_free_result
;
1238 * Some targets may set slight variations of PQ and PDT to signal
1239 * that no LUN is present, so don't add sdev in these cases.
1240 * Two specific examples are:
1241 * 1) NetApp targets: return PQ=1, PDT=0x1f
1242 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1243 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1246 * 1) SCSI SPC-3, pp. 145-146
1247 * PQ=1: "A peripheral device having the specified peripheral
1248 * device type is not connected to this logical unit. However, the
1249 * device server is capable of supporting the specified peripheral
1250 * device type on this logical unit."
1251 * PDT=0x1f: "Unknown or no device type"
1252 * 2) USB UFI 1.0, p. 20
1253 * PDT=00h Direct-access device (floppy)
1254 * PDT=1Fh none (no FDD connected to the requested logical unit)
1256 if (((result
[0] >> 5) == 1 || starget
->pdt_1f_for_no_lun
) &&
1257 (result
[0] & 0x1f) == 0x1f &&
1258 !scsi_is_wlun(lun
)) {
1259 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO
, sdev
,
1260 "scsi scan: peripheral device type"
1261 " of 31, no device added\n"));
1262 res
= SCSI_SCAN_TARGET_PRESENT
;
1263 goto out_free_result
;
1266 res
= scsi_add_lun(sdev
, result
, &bflags
, shost
->async_scan
);
1267 if (res
== SCSI_SCAN_LUN_PRESENT
) {
1268 if (bflags
& BLIST_KEY
) {
1270 scsi_unlock_floptical(sdev
, result
);
1277 if (res
== SCSI_SCAN_LUN_PRESENT
) {
1279 if (scsi_device_get(sdev
) == 0) {
1282 __scsi_remove_device(sdev
);
1283 res
= SCSI_SCAN_NO_RESPONSE
;
1287 __scsi_remove_device(sdev
);
1293 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1294 * @starget: pointer to target structure to scan
1295 * @bflags: black/white list flag for LUN 0
1296 * @scsi_level: Which version of the standard does this device adhere to
1297 * @rescan: passed to scsi_probe_add_lun()
1300 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1301 * scanned) to some maximum lun until a LUN is found with no device
1302 * attached. Use the bflags to figure out any oddities.
1304 * Modifies sdevscan->lun.
1306 static void scsi_sequential_lun_scan(struct scsi_target
*starget
,
1307 blist_flags_t bflags
, int scsi_level
,
1308 enum scsi_scan_mode rescan
)
1311 u64 sparse_lun
, lun
;
1312 struct Scsi_Host
*shost
= dev_to_shost(starget
->dev
.parent
);
1314 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO
, starget
,
1315 "scsi scan: Sequential scan\n"));
1317 max_dev_lun
= min(max_scsi_luns
, shost
->max_lun
);
1319 * If this device is known to support sparse multiple units,
1320 * override the other settings, and scan all of them. Normally,
1321 * SCSI-3 devices should be scanned via the REPORT LUNS.
1323 if (bflags
& BLIST_SPARSELUN
) {
1324 max_dev_lun
= shost
->max_lun
;
1330 * If less than SCSI_1_CCS, and no special lun scanning, stop
1331 * scanning; this matches 2.4 behaviour, but could just be a bug
1332 * (to continue scanning a SCSI_1_CCS device).
1334 * This test is broken. We might not have any device on lun0 for
1335 * a sparselun device, and if that's the case then how would we
1336 * know the real scsi_level, eh? It might make sense to just not
1337 * scan any SCSI_1 device for non-0 luns, but that check would best
1338 * go into scsi_alloc_sdev() and just have it return null when asked
1339 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1341 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1342 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1347 * If this device is known to support multiple units, override
1348 * the other settings, and scan all of them.
1350 if (bflags
& BLIST_FORCELUN
)
1351 max_dev_lun
= shost
->max_lun
;
1353 * REGAL CDC-4X: avoid hang after LUN 4
1355 if (bflags
& BLIST_MAX5LUN
)
1356 max_dev_lun
= min(5U, max_dev_lun
);
1358 * Do not scan SCSI-2 or lower device past LUN 7, unless
1361 if (scsi_level
< SCSI_3
&& !(bflags
& BLIST_LARGELUN
))
1362 max_dev_lun
= min(8U, max_dev_lun
);
1364 max_dev_lun
= min(256U, max_dev_lun
);
1367 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1368 * until we reach the max, or no LUN is found and we are not
1371 for (lun
= 1; lun
< max_dev_lun
; ++lun
)
1372 if ((scsi_probe_and_add_lun(starget
, lun
, NULL
, NULL
, rescan
,
1373 NULL
) != SCSI_SCAN_LUN_PRESENT
) &&
1379 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1380 * @starget: which target
1381 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1382 * @rescan: nonzero if we can skip code only needed on first scan
1385 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1386 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1388 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1389 * LUNs even if it's older than SCSI-3.
1390 * If BLIST_NOREPORTLUN is set, return 1 always.
1391 * If BLIST_NOLUN is set, return 0 always.
1392 * If starget->no_report_luns is set, return 1 always.
1395 * 0: scan completed (or no memory, so further scanning is futile)
1396 * 1: could not scan with REPORT LUN
1398 static int scsi_report_lun_scan(struct scsi_target
*starget
, blist_flags_t bflags
,
1399 enum scsi_scan_mode rescan
)
1401 unsigned char scsi_cmd
[MAX_COMMAND_SIZE
];
1402 unsigned int length
;
1404 unsigned int num_luns
;
1405 unsigned int retries
;
1407 struct scsi_lun
*lunp
, *lun_data
;
1408 struct scsi_sense_hdr sshdr
;
1409 struct scsi_device
*sdev
;
1410 struct Scsi_Host
*shost
= dev_to_shost(&starget
->dev
);
1411 const struct scsi_exec_args exec_args
= {
1417 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1418 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1419 * support more than 8 LUNs.
1420 * Don't attempt if the target doesn't support REPORT LUNS.
1422 if (bflags
& BLIST_NOREPORTLUN
)
1424 if (starget
->scsi_level
< SCSI_2
&&
1425 starget
->scsi_level
!= SCSI_UNKNOWN
)
1427 if (starget
->scsi_level
< SCSI_3
&&
1428 (!(bflags
& BLIST_REPORTLUN2
) || shost
->max_lun
<= 8))
1430 if (bflags
& BLIST_NOLUN
)
1432 if (starget
->no_report_luns
)
1435 if (!(sdev
= scsi_device_lookup_by_target(starget
, 0))) {
1436 sdev
= scsi_alloc_sdev(starget
, 0, NULL
);
1439 if (scsi_device_get(sdev
)) {
1440 __scsi_remove_device(sdev
);
1446 * Allocate enough to hold the header (the same size as one scsi_lun)
1447 * plus the number of luns we are requesting. 511 was the default
1448 * value of the now removed max_report_luns parameter.
1450 length
= (511 + 1) * sizeof(struct scsi_lun
);
1452 lun_data
= kmalloc(length
, GFP_KERNEL
);
1454 printk(ALLOC_FAILURE_MSG
, __func__
);
1458 scsi_cmd
[0] = REPORT_LUNS
;
1461 * bytes 1 - 5: reserved, set to zero.
1463 memset(&scsi_cmd
[1], 0, 5);
1466 * bytes 6 - 9: length of the command.
1468 put_unaligned_be32(length
, &scsi_cmd
[6]);
1470 scsi_cmd
[10] = 0; /* reserved */
1471 scsi_cmd
[11] = 0; /* control */
1474 * We can get a UNIT ATTENTION, for example a power on/reset, so
1475 * retry a few times (like sd.c does for TEST UNIT READY).
1476 * Experience shows some combinations of adapter/devices get at
1477 * least two power on/resets.
1479 * Illegal requests (for devices that do not support REPORT LUNS)
1480 * should come through as a check condition, and will not generate
1483 for (retries
= 0; retries
< 3; retries
++) {
1484 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO
, sdev
,
1485 "scsi scan: Sending REPORT LUNS to (try %d)\n",
1488 result
= scsi_execute_cmd(sdev
, scsi_cmd
, REQ_OP_DRV_IN
,
1490 SCSI_REPORT_LUNS_TIMEOUT
, 3,
1493 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO
, sdev
,
1494 "scsi scan: REPORT LUNS"
1495 " %s (try %d) result 0x%x\n",
1496 result
? "failed" : "successful",
1500 else if (scsi_sense_valid(&sshdr
)) {
1501 if (sshdr
.sense_key
!= UNIT_ATTENTION
)
1508 * The device probably does not support a REPORT LUN command
1515 * Get the length from the first four bytes of lun_data.
1517 if (get_unaligned_be32(lun_data
->scsi_lun
) +
1518 sizeof(struct scsi_lun
) > length
) {
1519 length
= get_unaligned_be32(lun_data
->scsi_lun
) +
1520 sizeof(struct scsi_lun
);
1524 length
= get_unaligned_be32(lun_data
->scsi_lun
);
1526 num_luns
= (length
/ sizeof(struct scsi_lun
));
1528 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO
, sdev
,
1529 "scsi scan: REPORT LUN scan\n"));
1532 * Scan the luns in lun_data. The entry at offset 0 is really
1533 * the header, so start at 1 and go up to and including num_luns.
1535 for (lunp
= &lun_data
[1]; lunp
<= &lun_data
[num_luns
]; lunp
++) {
1536 lun
= scsilun_to_int(lunp
);
1538 if (lun
> sdev
->host
->max_lun
) {
1539 sdev_printk(KERN_WARNING
, sdev
,
1540 "lun%llu has a LUN larger than"
1541 " allowed by the host adapter\n", lun
);
1545 res
= scsi_probe_and_add_lun(starget
,
1546 lun
, NULL
, NULL
, rescan
, NULL
);
1547 if (res
== SCSI_SCAN_NO_RESPONSE
) {
1549 * Got some results, but now none, abort.
1551 sdev_printk(KERN_ERR
, sdev
,
1552 "Unexpected response"
1553 " from lun %llu while scanning, scan"
1554 " aborted\n", (unsigned long long)lun
);
1563 if (scsi_device_created(sdev
))
1565 * the sdev we used didn't appear in the report luns scan
1567 __scsi_remove_device(sdev
);
1568 scsi_device_put(sdev
);
1572 struct scsi_device
*__scsi_add_device(struct Scsi_Host
*shost
, uint channel
,
1573 uint id
, u64 lun
, void *hostdata
)
1575 struct scsi_device
*sdev
= ERR_PTR(-ENODEV
);
1576 struct device
*parent
= &shost
->shost_gendev
;
1577 struct scsi_target
*starget
;
1579 if (strncmp(scsi_scan_type
, "none", 4) == 0)
1580 return ERR_PTR(-ENODEV
);
1582 starget
= scsi_alloc_target(parent
, channel
, id
);
1584 return ERR_PTR(-ENOMEM
);
1585 scsi_autopm_get_target(starget
);
1587 mutex_lock(&shost
->scan_mutex
);
1588 if (!shost
->async_scan
)
1589 scsi_complete_async_scans();
1591 if (scsi_host_scan_allowed(shost
) && scsi_autopm_get_host(shost
) == 0) {
1592 scsi_probe_and_add_lun(starget
, lun
, NULL
, &sdev
,
1593 SCSI_SCAN_RESCAN
, hostdata
);
1594 scsi_autopm_put_host(shost
);
1596 mutex_unlock(&shost
->scan_mutex
);
1597 scsi_autopm_put_target(starget
);
1599 * paired with scsi_alloc_target(). Target will be destroyed unless
1600 * scsi_probe_and_add_lun made an underlying device visible
1602 scsi_target_reap(starget
);
1603 put_device(&starget
->dev
);
1607 EXPORT_SYMBOL(__scsi_add_device
);
1609 int scsi_add_device(struct Scsi_Host
*host
, uint channel
,
1610 uint target
, u64 lun
)
1612 struct scsi_device
*sdev
=
1613 __scsi_add_device(host
, channel
, target
, lun
, NULL
);
1615 return PTR_ERR(sdev
);
1617 scsi_device_put(sdev
);
1620 EXPORT_SYMBOL(scsi_add_device
);
1622 int scsi_rescan_device(struct scsi_device
*sdev
)
1624 struct device
*dev
= &sdev
->sdev_gendev
;
1630 * Bail out if the device or its queue are not running. Otherwise,
1631 * the rescan may block waiting for commands to be executed, with us
1632 * holding the device lock. This can result in a potential deadlock
1633 * in the power management core code when system resume is on-going.
1635 if (sdev
->sdev_state
!= SDEV_RUNNING
||
1636 blk_queue_pm_only(sdev
->request_queue
)) {
1641 scsi_attach_vpd(sdev
);
1642 scsi_cdl_check(sdev
);
1644 if (sdev
->handler
&& sdev
->handler
->rescan
)
1645 sdev
->handler
->rescan(sdev
);
1647 if (dev
->driver
&& try_module_get(dev
->driver
->owner
)) {
1648 struct scsi_driver
*drv
= to_scsi_driver(dev
->driver
);
1652 module_put(dev
->driver
->owner
);
1660 EXPORT_SYMBOL(scsi_rescan_device
);
1662 static void __scsi_scan_target(struct device
*parent
, unsigned int channel
,
1663 unsigned int id
, u64 lun
, enum scsi_scan_mode rescan
)
1665 struct Scsi_Host
*shost
= dev_to_shost(parent
);
1666 blist_flags_t bflags
= 0;
1668 struct scsi_target
*starget
;
1670 if (shost
->this_id
== id
)
1672 * Don't scan the host adapter
1676 starget
= scsi_alloc_target(parent
, channel
, id
);
1679 scsi_autopm_get_target(starget
);
1681 if (lun
!= SCAN_WILD_CARD
) {
1683 * Scan for a specific host/chan/id/lun.
1685 scsi_probe_and_add_lun(starget
, lun
, NULL
, NULL
, rescan
, NULL
);
1690 * Scan LUN 0, if there is some response, scan further. Ideally, we
1691 * would not configure LUN 0 until all LUNs are scanned.
1693 res
= scsi_probe_and_add_lun(starget
, 0, &bflags
, NULL
, rescan
, NULL
);
1694 if (res
== SCSI_SCAN_LUN_PRESENT
|| res
== SCSI_SCAN_TARGET_PRESENT
) {
1695 if (scsi_report_lun_scan(starget
, bflags
, rescan
) != 0)
1697 * The REPORT LUN did not scan the target,
1698 * do a sequential scan.
1700 scsi_sequential_lun_scan(starget
, bflags
,
1701 starget
->scsi_level
, rescan
);
1705 scsi_autopm_put_target(starget
);
1707 * paired with scsi_alloc_target(): determine if the target has
1708 * any children at all and if not, nuke it
1710 scsi_target_reap(starget
);
1712 put_device(&starget
->dev
);
1716 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1717 * @parent: host to scan
1718 * @channel: channel to scan
1719 * @id: target id to scan
1720 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1721 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for
1722 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
1723 * and SCSI_SCAN_MANUAL to force scanning even if
1724 * 'scan=manual' is set.
1727 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1728 * and possibly all LUNs on the target id.
1730 * First try a REPORT LUN scan, if that does not scan the target, do a
1731 * sequential scan of LUNs on the target id.
1733 void scsi_scan_target(struct device
*parent
, unsigned int channel
,
1734 unsigned int id
, u64 lun
, enum scsi_scan_mode rescan
)
1736 struct Scsi_Host
*shost
= dev_to_shost(parent
);
1738 if (strncmp(scsi_scan_type
, "none", 4) == 0)
1741 if (rescan
!= SCSI_SCAN_MANUAL
&&
1742 strncmp(scsi_scan_type
, "manual", 6) == 0)
1745 mutex_lock(&shost
->scan_mutex
);
1746 if (!shost
->async_scan
)
1747 scsi_complete_async_scans();
1749 if (scsi_host_scan_allowed(shost
) && scsi_autopm_get_host(shost
) == 0) {
1750 __scsi_scan_target(parent
, channel
, id
, lun
, rescan
);
1751 scsi_autopm_put_host(shost
);
1753 mutex_unlock(&shost
->scan_mutex
);
1755 EXPORT_SYMBOL(scsi_scan_target
);
1757 static void scsi_scan_channel(struct Scsi_Host
*shost
, unsigned int channel
,
1758 unsigned int id
, u64 lun
,
1759 enum scsi_scan_mode rescan
)
1763 if (id
== SCAN_WILD_CARD
)
1764 for (id
= 0; id
< shost
->max_id
; ++id
) {
1766 * XXX adapter drivers when possible (FCP, iSCSI)
1767 * could modify max_id to match the current max,
1768 * not the absolute max.
1770 * XXX add a shost id iterator, so for example,
1771 * the FC ID can be the same as a target id
1772 * without a huge overhead of sparse id's.
1774 if (shost
->reverse_ordering
)
1776 * Scan from high to low id.
1778 order_id
= shost
->max_id
- id
- 1;
1781 __scsi_scan_target(&shost
->shost_gendev
, channel
,
1782 order_id
, lun
, rescan
);
1785 __scsi_scan_target(&shost
->shost_gendev
, channel
,
1789 int scsi_scan_host_selected(struct Scsi_Host
*shost
, unsigned int channel
,
1790 unsigned int id
, u64 lun
,
1791 enum scsi_scan_mode rescan
)
1793 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO
, shost
,
1794 "%s: <%u:%u:%llu>\n",
1795 __func__
, channel
, id
, lun
));
1797 if (((channel
!= SCAN_WILD_CARD
) && (channel
> shost
->max_channel
)) ||
1798 ((id
!= SCAN_WILD_CARD
) && (id
>= shost
->max_id
)) ||
1799 ((lun
!= SCAN_WILD_CARD
) && (lun
>= shost
->max_lun
)))
1802 mutex_lock(&shost
->scan_mutex
);
1803 if (!shost
->async_scan
)
1804 scsi_complete_async_scans();
1806 if (scsi_host_scan_allowed(shost
) && scsi_autopm_get_host(shost
) == 0) {
1807 if (channel
== SCAN_WILD_CARD
)
1808 for (channel
= 0; channel
<= shost
->max_channel
;
1810 scsi_scan_channel(shost
, channel
, id
, lun
,
1813 scsi_scan_channel(shost
, channel
, id
, lun
, rescan
);
1814 scsi_autopm_put_host(shost
);
1816 mutex_unlock(&shost
->scan_mutex
);
1821 static void scsi_sysfs_add_devices(struct Scsi_Host
*shost
)
1823 struct scsi_device
*sdev
;
1824 shost_for_each_device(sdev
, shost
) {
1825 /* target removed before the device could be added */
1826 if (sdev
->sdev_state
== SDEV_DEL
)
1828 /* If device is already visible, skip adding it to sysfs */
1829 if (sdev
->is_visible
)
1831 if (!scsi_host_scan_allowed(shost
) ||
1832 scsi_sysfs_add_sdev(sdev
) != 0)
1833 __scsi_remove_device(sdev
);
1838 * scsi_prep_async_scan - prepare for an async scan
1839 * @shost: the host which will be scanned
1840 * Returns: a cookie to be passed to scsi_finish_async_scan()
1842 * Tells the midlayer this host is going to do an asynchronous scan.
1843 * It reserves the host's position in the scanning list and ensures
1844 * that other asynchronous scans started after this one won't affect the
1845 * ordering of the discovered devices.
1847 static struct async_scan_data
*scsi_prep_async_scan(struct Scsi_Host
*shost
)
1849 struct async_scan_data
*data
= NULL
;
1850 unsigned long flags
;
1852 if (strncmp(scsi_scan_type
, "sync", 4) == 0)
1855 mutex_lock(&shost
->scan_mutex
);
1856 if (shost
->async_scan
) {
1857 shost_printk(KERN_DEBUG
, shost
, "%s called twice\n", __func__
);
1861 data
= kmalloc(sizeof(*data
), GFP_KERNEL
);
1864 data
->shost
= scsi_host_get(shost
);
1867 init_completion(&data
->prev_finished
);
1869 spin_lock_irqsave(shost
->host_lock
, flags
);
1870 shost
->async_scan
= 1;
1871 spin_unlock_irqrestore(shost
->host_lock
, flags
);
1872 mutex_unlock(&shost
->scan_mutex
);
1874 spin_lock(&async_scan_lock
);
1875 if (list_empty(&scanning_hosts
))
1876 complete(&data
->prev_finished
);
1877 list_add_tail(&data
->list
, &scanning_hosts
);
1878 spin_unlock(&async_scan_lock
);
1883 mutex_unlock(&shost
->scan_mutex
);
1889 * scsi_finish_async_scan - asynchronous scan has finished
1890 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1892 * All the devices currently attached to this host have been found.
1893 * This function announces all the devices it has found to the rest
1896 static void scsi_finish_async_scan(struct async_scan_data
*data
)
1898 struct Scsi_Host
*shost
;
1899 unsigned long flags
;
1904 shost
= data
->shost
;
1906 mutex_lock(&shost
->scan_mutex
);
1908 if (!shost
->async_scan
) {
1909 shost_printk(KERN_INFO
, shost
, "%s called twice\n", __func__
);
1911 mutex_unlock(&shost
->scan_mutex
);
1915 wait_for_completion(&data
->prev_finished
);
1917 scsi_sysfs_add_devices(shost
);
1919 spin_lock_irqsave(shost
->host_lock
, flags
);
1920 shost
->async_scan
= 0;
1921 spin_unlock_irqrestore(shost
->host_lock
, flags
);
1923 mutex_unlock(&shost
->scan_mutex
);
1925 spin_lock(&async_scan_lock
);
1926 list_del(&data
->list
);
1927 if (!list_empty(&scanning_hosts
)) {
1928 struct async_scan_data
*next
= list_entry(scanning_hosts
.next
,
1929 struct async_scan_data
, list
);
1930 complete(&next
->prev_finished
);
1932 spin_unlock(&async_scan_lock
);
1934 scsi_autopm_put_host(shost
);
1935 scsi_host_put(shost
);
1939 static void do_scsi_scan_host(struct Scsi_Host
*shost
)
1941 if (shost
->hostt
->scan_finished
) {
1942 unsigned long start
= jiffies
;
1943 if (shost
->hostt
->scan_start
)
1944 shost
->hostt
->scan_start(shost
);
1946 while (!shost
->hostt
->scan_finished(shost
, jiffies
- start
))
1949 scsi_scan_host_selected(shost
, SCAN_WILD_CARD
, SCAN_WILD_CARD
,
1950 SCAN_WILD_CARD
, SCSI_SCAN_INITIAL
);
1954 static void do_scan_async(void *_data
, async_cookie_t c
)
1956 struct async_scan_data
*data
= _data
;
1957 struct Scsi_Host
*shost
= data
->shost
;
1959 do_scsi_scan_host(shost
);
1960 scsi_finish_async_scan(data
);
1964 * scsi_scan_host - scan the given adapter
1965 * @shost: adapter to scan
1967 void scsi_scan_host(struct Scsi_Host
*shost
)
1969 struct async_scan_data
*data
;
1971 if (strncmp(scsi_scan_type
, "none", 4) == 0 ||
1972 strncmp(scsi_scan_type
, "manual", 6) == 0)
1974 if (scsi_autopm_get_host(shost
) < 0)
1977 data
= scsi_prep_async_scan(shost
);
1979 do_scsi_scan_host(shost
);
1980 scsi_autopm_put_host(shost
);
1984 /* register with the async subsystem so wait_for_device_probe()
1985 * will flush this work
1987 async_schedule(do_scan_async
, data
);
1989 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1991 EXPORT_SYMBOL(scsi_scan_host
);
1993 void scsi_forget_host(struct Scsi_Host
*shost
)
1995 struct scsi_device
*sdev
;
1996 unsigned long flags
;
1999 spin_lock_irqsave(shost
->host_lock
, flags
);
2000 list_for_each_entry(sdev
, &shost
->__devices
, siblings
) {
2001 if (sdev
->sdev_state
== SDEV_DEL
)
2003 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2004 __scsi_remove_device(sdev
);
2007 spin_unlock_irqrestore(shost
->host_lock
, flags
);