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scsi_scan.c
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scsi_scan.c
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// SPDX-License-Identifier: GPL-2.0
/*
* scsi_scan.c
*
* Copyright (C) 2000 Eric Youngdale,
* Copyright (C) 2002 Patrick Mansfield
*
* The general scanning/probing algorithm is as follows, exceptions are
* made to it depending on device specific flags, compilation options, and
* global variable (boot or module load time) settings.
*
* A specific LUN is scanned via an INQUIRY command; if the LUN has a
* device attached, a scsi_device is allocated and setup for it.
*
* For every id of every channel on the given host:
*
* Scan LUN 0; if the target responds to LUN 0 (even if there is no
* device or storage attached to LUN 0):
*
* If LUN 0 has a device attached, allocate and setup a
* scsi_device for it.
*
* If target is SCSI-3 or up, issue a REPORT LUN, and scan
* all of the LUNs returned by the REPORT LUN; else,
* sequentially scan LUNs up until some maximum is reached,
* or a LUN is seen that cannot have a device attached to it.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/spinlock.h>
#include <linux/async.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_devinfo.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_dh.h>
#include <scsi/scsi_eh.h>
#include "scsi_priv.h"
#include "scsi_logging.h"
#define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
" SCSI scanning, some SCSI devices might not be configured\n"
/*
* Default timeout
*/
#define SCSI_TIMEOUT (2*HZ)
#define SCSI_REPORT_LUNS_TIMEOUT (30*HZ)
/*
* Prefix values for the SCSI id's (stored in sysfs name field)
*/
#define SCSI_UID_SER_NUM 'S'
#define SCSI_UID_UNKNOWN 'Z'
/*
* Return values of some of the scanning functions.
*
* SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
* includes allocation or general failures preventing IO from being sent.
*
* SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
* on the given LUN.
*
* SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
* given LUN.
*/
#define SCSI_SCAN_NO_RESPONSE 0
#define SCSI_SCAN_TARGET_PRESENT 1
#define SCSI_SCAN_LUN_PRESENT 2
static const char *scsi_null_device_strs = "nullnullnullnull";
#define MAX_SCSI_LUNS 512
static u64 max_scsi_luns = MAX_SCSI_LUNS;
module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_luns,
"last scsi LUN (should be between 1 and 2^64-1)");
#ifdef CONFIG_SCSI_SCAN_ASYNC
#define SCSI_SCAN_TYPE_DEFAULT "async"
#else
#define SCSI_SCAN_TYPE_DEFAULT "sync"
#endif
char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT;
module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type),
S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scan, "sync, async, manual, or none. "
"Setting to 'manual' disables automatic scanning, but allows "
"for manual device scan via the 'scan' sysfs attribute.");
static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(inq_timeout,
"Timeout (in seconds) waiting for devices to answer INQUIRY."
" Default is 20. Some devices may need more; most need less.");
/* This lock protects only this list */
static DEFINE_SPINLOCK(async_scan_lock);
static LIST_HEAD(scanning_hosts);
struct async_scan_data {
struct list_head list;
struct Scsi_Host *shost;
struct completion prev_finished;
};
/**
* scsi_enable_async_suspend - Enable async suspend and resume
*/
void scsi_enable_async_suspend(struct device *dev)
{
/*
* If a user has disabled async probing a likely reason is due to a
* storage enclosure that does not inject staggered spin-ups. For
* safety, make resume synchronous as well in that case.
*/
if (strncmp(scsi_scan_type, "async", 5) != 0)
return;
/* Enable asynchronous suspend and resume. */
device_enable_async_suspend(dev);
}
/**
* scsi_complete_async_scans - Wait for asynchronous scans to complete
*
* When this function returns, any host which started scanning before
* this function was called will have finished its scan. Hosts which
* started scanning after this function was called may or may not have
* finished.
*/
int scsi_complete_async_scans(void)
{
struct async_scan_data *data;
do {
if (list_empty(&scanning_hosts))
return 0;
/* If we can't get memory immediately, that's OK. Just
* sleep a little. Even if we never get memory, the async
* scans will finish eventually.
*/
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
msleep(1);
} while (!data);
data->shost = NULL;
init_completion(&data->prev_finished);
spin_lock(&async_scan_lock);
/* Check that there's still somebody else on the list */
if (list_empty(&scanning_hosts))
goto done;
list_add_tail(&data->list, &scanning_hosts);
spin_unlock(&async_scan_lock);
printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
wait_for_completion(&data->prev_finished);
spin_lock(&async_scan_lock);
list_del(&data->list);
if (!list_empty(&scanning_hosts)) {
struct async_scan_data *next = list_entry(scanning_hosts.next,
struct async_scan_data, list);
complete(&next->prev_finished);
}
done:
spin_unlock(&async_scan_lock);
kfree(data);
return 0;
}
/**
* scsi_unlock_floptical - unlock device via a special MODE SENSE command
* @sdev: scsi device to send command to
* @result: area to store the result of the MODE SENSE
*
* Description:
* Send a vendor specific MODE SENSE (not a MODE SELECT) command.
* Called for BLIST_KEY devices.
**/
static void scsi_unlock_floptical(struct scsi_device *sdev,
unsigned char *result)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
scsi_cmd[0] = MODE_SENSE;
scsi_cmd[1] = 0;
scsi_cmd[2] = 0x2e;
scsi_cmd[3] = 0;
scsi_cmd[4] = 0x2a; /* size */
scsi_cmd[5] = 0;
scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
SCSI_TIMEOUT, 3, NULL);
}
static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev,
unsigned int depth)
{
int new_shift = sbitmap_calculate_shift(depth);
bool need_alloc = !sdev->budget_map.map;
bool need_free = false;
int ret;
struct sbitmap sb_backup;
/*
* realloc if new shift is calculated, which is caused by setting
* up one new default queue depth after calling ->slave_configure
*/
if (!need_alloc && new_shift != sdev->budget_map.shift)
need_alloc = need_free = true;
if (!need_alloc)
return 0;
/*
* Request queue has to be frozen for reallocating budget map,
* and here disk isn't added yet, so freezing is pretty fast
*/
if (need_free) {
blk_mq_freeze_queue(sdev->request_queue);
sb_backup = sdev->budget_map;
}
ret = sbitmap_init_node(&sdev->budget_map,
scsi_device_max_queue_depth(sdev),
new_shift, GFP_KERNEL,
sdev->request_queue->node, false, true);
if (need_free) {
if (ret)
sdev->budget_map = sb_backup;
else
sbitmap_free(&sb_backup);
ret = 0;
blk_mq_unfreeze_queue(sdev->request_queue);
}
return ret;
}
/**
* scsi_alloc_sdev - allocate and setup a scsi_Device
* @starget: which target to allocate a &scsi_device for
* @lun: which lun
* @hostdata: usually NULL and set by ->slave_alloc instead
*
* Description:
* Allocate, initialize for io, and return a pointer to a scsi_Device.
* Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
* adds scsi_Device to the appropriate list.
*
* Return value:
* scsi_Device pointer, or NULL on failure.
**/
static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
u64 lun, void *hostdata)
{
unsigned int depth;
struct scsi_device *sdev;
struct request_queue *q;
int display_failure_msg = 1, ret;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
GFP_KERNEL);
if (!sdev)
goto out;
sdev->vendor = scsi_null_device_strs;
sdev->model = scsi_null_device_strs;
sdev->rev = scsi_null_device_strs;
sdev->host = shost;
sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
sdev->id = starget->id;
sdev->lun = lun;
sdev->channel = starget->channel;
mutex_init(&sdev->state_mutex);
sdev->sdev_state = SDEV_CREATED;
INIT_LIST_HEAD(&sdev->siblings);
INIT_LIST_HEAD(&sdev->same_target_siblings);
INIT_LIST_HEAD(&sdev->starved_entry);
INIT_LIST_HEAD(&sdev->event_list);
spin_lock_init(&sdev->list_lock);
mutex_init(&sdev->inquiry_mutex);
INIT_WORK(&sdev->event_work, scsi_evt_thread);
INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
sdev->sdev_gendev.parent = get_device(&starget->dev);
sdev->sdev_target = starget;
/* usually NULL and set by ->slave_alloc instead */
sdev->hostdata = hostdata;
/* if the device needs this changing, it may do so in the
* slave_configure function */
sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
/*
* Some low level driver could use device->type
*/
sdev->type = -1;
/*
* Assume that the device will have handshaking problems,
* and then fix this field later if it turns out it
* doesn't
*/
sdev->borken = 1;
sdev->sg_reserved_size = INT_MAX;
q = blk_mq_init_queue(&sdev->host->tag_set);
if (IS_ERR(q)) {
/* release fn is set up in scsi_sysfs_device_initialise, so
* have to free and put manually here */
put_device(&starget->dev);
kfree(sdev);
goto out;
}
sdev->request_queue = q;
q->queuedata = sdev;
__scsi_init_queue(sdev->host, q);
WARN_ON_ONCE(!blk_get_queue(q));
depth = sdev->host->cmd_per_lun ?: 1;
/*
* Use .can_queue as budget map's depth because we have to
* support adjusting queue depth from sysfs. Meantime use
* default device queue depth to figure out sbitmap shift
* since we use this queue depth most of times.
*/
if (scsi_realloc_sdev_budget_map(sdev, depth)) {
put_device(&starget->dev);
kfree(sdev);
goto out;
}
scsi_change_queue_depth(sdev, depth);
scsi_sysfs_device_initialize(sdev);
if (shost->hostt->slave_alloc) {
ret = shost->hostt->slave_alloc(sdev);
if (ret) {
/*
* if LLDD reports slave not present, don't clutter
* console with alloc failure messages
*/
if (ret == -ENXIO)
display_failure_msg = 0;
goto out_device_destroy;
}
}
return sdev;
out_device_destroy:
__scsi_remove_device(sdev);
out:
if (display_failure_msg)
printk(ALLOC_FAILURE_MSG, __func__);
return NULL;
}
static void scsi_target_destroy(struct scsi_target *starget)
{
struct device *dev = &starget->dev;
struct Scsi_Host *shost = dev_to_shost(dev->parent);
unsigned long flags;
BUG_ON(starget->state == STARGET_DEL);
starget->state = STARGET_DEL;
transport_destroy_device(dev);
spin_lock_irqsave(shost->host_lock, flags);
if (shost->hostt->target_destroy)
shost->hostt->target_destroy(starget);
list_del_init(&starget->siblings);
spin_unlock_irqrestore(shost->host_lock, flags);
put_device(dev);
}
static void scsi_target_dev_release(struct device *dev)
{
struct device *parent = dev->parent;
struct scsi_target *starget = to_scsi_target(dev);
kfree(starget);
put_device(parent);
}
static struct device_type scsi_target_type = {
.name = "scsi_target",
.release = scsi_target_dev_release,
};
int scsi_is_target_device(const struct device *dev)
{
return dev->type == &scsi_target_type;
}
EXPORT_SYMBOL(scsi_is_target_device);
static struct scsi_target *__scsi_find_target(struct device *parent,
int channel, uint id)
{
struct scsi_target *starget, *found_starget = NULL;
struct Scsi_Host *shost = dev_to_shost(parent);
/*
* Search for an existing target for this sdev.
*/
list_for_each_entry(starget, &shost->__targets, siblings) {
if (starget->id == id &&
starget->channel == channel) {
found_starget = starget;
break;
}
}
if (found_starget)
get_device(&found_starget->dev);
return found_starget;
}
/**
* scsi_target_reap_ref_release - remove target from visibility
* @kref: the reap_ref in the target being released
*
* Called on last put of reap_ref, which is the indication that no device
* under this target is visible anymore, so render the target invisible in
* sysfs. Note: we have to be in user context here because the target reaps
* should be done in places where the scsi device visibility is being removed.
*/
static void scsi_target_reap_ref_release(struct kref *kref)
{
struct scsi_target *starget
= container_of(kref, struct scsi_target, reap_ref);
/*
* if we get here and the target is still in a CREATED state that
* means it was allocated but never made visible (because a scan
* turned up no LUNs), so don't call device_del() on it.
*/
if ((starget->state != STARGET_CREATED) &&
(starget->state != STARGET_CREATED_REMOVE)) {
transport_remove_device(&starget->dev);
device_del(&starget->dev);
}
scsi_target_destroy(starget);
}
static void scsi_target_reap_ref_put(struct scsi_target *starget)
{
kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
}
/**
* scsi_alloc_target - allocate a new or find an existing target
* @parent: parent of the target (need not be a scsi host)
* @channel: target channel number (zero if no channels)
* @id: target id number
*
* Return an existing target if one exists, provided it hasn't already
* gone into STARGET_DEL state, otherwise allocate a new target.
*
* The target is returned with an incremented reference, so the caller
* is responsible for both reaping and doing a last put
*/
static struct scsi_target *scsi_alloc_target(struct device *parent,
int channel, uint id)
{
struct Scsi_Host *shost = dev_to_shost(parent);
struct device *dev = NULL;
unsigned long flags;
const int size = sizeof(struct scsi_target)
+ shost->transportt->target_size;
struct scsi_target *starget;
struct scsi_target *found_target;
int error, ref_got;
starget = kzalloc(size, GFP_KERNEL);
if (!starget) {
printk(KERN_ERR "%s: allocation failure\n", __func__);
return NULL;
}
dev = &starget->dev;
device_initialize(dev);
kref_init(&starget->reap_ref);
dev->parent = get_device(parent);
dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
dev->bus = &scsi_bus_type;
dev->type = &scsi_target_type;
scsi_enable_async_suspend(dev);
starget->id = id;
starget->channel = channel;
starget->can_queue = 0;
INIT_LIST_HEAD(&starget->siblings);
INIT_LIST_HEAD(&starget->devices);
starget->state = STARGET_CREATED;
starget->scsi_level = SCSI_2;
starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
retry:
spin_lock_irqsave(shost->host_lock, flags);
found_target = __scsi_find_target(parent, channel, id);
if (found_target)
goto found;
list_add_tail(&starget->siblings, &shost->__targets);
spin_unlock_irqrestore(shost->host_lock, flags);
/* allocate and add */
transport_setup_device(dev);
if (shost->hostt->target_alloc) {
error = shost->hostt->target_alloc(starget);
if(error) {
if (error != -ENXIO)
dev_err(dev, "target allocation failed, error %d\n", error);
/* don't want scsi_target_reap to do the final
* put because it will be under the host lock */
scsi_target_destroy(starget);
return NULL;
}
}
get_device(dev);
return starget;
found:
/*
* release routine already fired if kref is zero, so if we can still
* take the reference, the target must be alive. If we can't, it must
* be dying and we need to wait for a new target
*/
ref_got = kref_get_unless_zero(&found_target->reap_ref);
spin_unlock_irqrestore(shost->host_lock, flags);
if (ref_got) {
put_device(dev);
return found_target;
}
/*
* Unfortunately, we found a dying target; need to wait until it's
* dead before we can get a new one. There is an anomaly here. We
* *should* call scsi_target_reap() to balance the kref_get() of the
* reap_ref above. However, since the target being released, it's
* already invisible and the reap_ref is irrelevant. If we call
* scsi_target_reap() we might spuriously do another device_del() on
* an already invisible target.
*/
put_device(&found_target->dev);
/*
* length of time is irrelevant here, we just want to yield the CPU
* for a tick to avoid busy waiting for the target to die.
*/
msleep(1);
goto retry;
}
/**
* scsi_target_reap - check to see if target is in use and destroy if not
* @starget: target to be checked
*
* This is used after removing a LUN or doing a last put of the target
* it checks atomically that nothing is using the target and removes
* it if so.
*/
void scsi_target_reap(struct scsi_target *starget)
{
/*
* serious problem if this triggers: STARGET_DEL is only set in the if
* the reap_ref drops to zero, so we're trying to do another final put
* on an already released kref
*/
BUG_ON(starget->state == STARGET_DEL);
scsi_target_reap_ref_put(starget);
}
/**
* scsi_sanitize_inquiry_string - remove non-graphical chars from an
* INQUIRY result string
* @s: INQUIRY result string to sanitize
* @len: length of the string
*
* Description:
* The SCSI spec says that INQUIRY vendor, product, and revision
* strings must consist entirely of graphic ASCII characters,
* padded on the right with spaces. Since not all devices obey
* this rule, we will replace non-graphic or non-ASCII characters
* with spaces. Exception: a NUL character is interpreted as a
* string terminator, so all the following characters are set to
* spaces.
**/
void scsi_sanitize_inquiry_string(unsigned char *s, int len)
{
int terminated = 0;
for (; len > 0; (--len, ++s)) {
if (*s == 0)
terminated = 1;
if (terminated || *s < 0x20 || *s > 0x7e)
*s = ' ';
}
}
EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
/**
* scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
* @sdev: scsi_device to probe
* @inq_result: area to store the INQUIRY result
* @result_len: len of inq_result
* @bflags: store any bflags found here
*
* Description:
* Probe the lun associated with @req using a standard SCSI INQUIRY;
*
* If the INQUIRY is successful, zero is returned and the
* INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
* are copied to the scsi_device any flags value is stored in *@bflags.
**/
static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
int result_len, blist_flags_t *bflags)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
int first_inquiry_len, try_inquiry_len, next_inquiry_len;
int response_len = 0;
int pass, count, result;
struct scsi_sense_hdr sshdr;
*bflags = 0;
/* Perform up to 3 passes. The first pass uses a conservative
* transfer length of 36 unless sdev->inquiry_len specifies a
* different value. */
first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
try_inquiry_len = first_inquiry_len;
pass = 1;
next_pass:
SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
"scsi scan: INQUIRY pass %d length %d\n",
pass, try_inquiry_len));
/* Each pass gets up to three chances to ignore Unit Attention */
for (count = 0; count < 3; ++count) {
int resid;
memset(scsi_cmd, 0, 6);
scsi_cmd[0] = INQUIRY;
scsi_cmd[4] = (unsigned char) try_inquiry_len;
memset(inq_result, 0, try_inquiry_len);
result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
inq_result, try_inquiry_len, &sshdr,
HZ / 2 + HZ * scsi_inq_timeout, 3,
&resid);
SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
"scsi scan: INQUIRY %s with code 0x%x\n",
result ? "failed" : "successful", result));
if (result > 0) {
/*
* not-ready to ready transition [asc/ascq=0x28/0x0]
* or power-on, reset [asc/ascq=0x29/0x0], continue.
* INQUIRY should not yield UNIT_ATTENTION
* but many buggy devices do so anyway.
*/
if (scsi_status_is_check_condition(result) &&
scsi_sense_valid(&sshdr)) {
if ((sshdr.sense_key == UNIT_ATTENTION) &&
((sshdr.asc == 0x28) ||
(sshdr.asc == 0x29)) &&
(sshdr.ascq == 0))
continue;
}
} else if (result == 0) {
/*
* if nothing was transferred, we try
* again. It's a workaround for some USB
* devices.
*/
if (resid == try_inquiry_len)
continue;
}
break;
}
if (result == 0) {
scsi_sanitize_inquiry_string(&inq_result[8], 8);
scsi_sanitize_inquiry_string(&inq_result[16], 16);
scsi_sanitize_inquiry_string(&inq_result[32], 4);
response_len = inq_result[4] + 5;
if (response_len > 255)
response_len = first_inquiry_len; /* sanity */
/*
* Get any flags for this device.
*
* XXX add a bflags to scsi_device, and replace the
* corresponding bit fields in scsi_device, so bflags
* need not be passed as an argument.
*/
*bflags = scsi_get_device_flags(sdev, &inq_result[8],
&inq_result[16]);
/* When the first pass succeeds we gain information about
* what larger transfer lengths might work. */
if (pass == 1) {
if (BLIST_INQUIRY_36 & *bflags)
next_inquiry_len = 36;
else if (sdev->inquiry_len)
next_inquiry_len = sdev->inquiry_len;
else
next_inquiry_len = response_len;
/* If more data is available perform the second pass */
if (next_inquiry_len > try_inquiry_len) {
try_inquiry_len = next_inquiry_len;
pass = 2;
goto next_pass;
}
}
} else if (pass == 2) {
sdev_printk(KERN_INFO, sdev,
"scsi scan: %d byte inquiry failed. "
"Consider BLIST_INQUIRY_36 for this device\n",
try_inquiry_len);
/* If this pass failed, the third pass goes back and transfers
* the same amount as we successfully got in the first pass. */
try_inquiry_len = first_inquiry_len;
pass = 3;
goto next_pass;
}
/* If the last transfer attempt got an error, assume the
* peripheral doesn't exist or is dead. */
if (result)
return -EIO;
/* Don't report any more data than the device says is valid */
sdev->inquiry_len = min(try_inquiry_len, response_len);
/*
* XXX Abort if the response length is less than 36? If less than
* 32, the lookup of the device flags (above) could be invalid,
* and it would be possible to take an incorrect action - we do
* not want to hang because of a short INQUIRY. On the flip side,
* if the device is spun down or becoming ready (and so it gives a
* short INQUIRY), an abort here prevents any further use of the
* device, including spin up.
*
* On the whole, the best approach seems to be to assume the first
* 36 bytes are valid no matter what the device says. That's
* better than copying < 36 bytes to the inquiry-result buffer
* and displaying garbage for the Vendor, Product, or Revision
* strings.
*/
if (sdev->inquiry_len < 36) {
if (!sdev->host->short_inquiry) {
shost_printk(KERN_INFO, sdev->host,
"scsi scan: INQUIRY result too short (%d),"
" using 36\n", sdev->inquiry_len);
sdev->host->short_inquiry = 1;
}
sdev->inquiry_len = 36;
}
/*
* Related to the above issue:
*
* XXX Devices (disk or all?) should be sent a TEST UNIT READY,
* and if not ready, sent a START_STOP to start (maybe spin up) and
* then send the INQUIRY again, since the INQUIRY can change after
* a device is initialized.
*
* Ideally, start a device if explicitly asked to do so. This
* assumes that a device is spun up on power on, spun down on
* request, and then spun up on request.
*/
/*
* The scanning code needs to know the scsi_level, even if no
* device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
* non-zero LUNs can be scanned.
*/
sdev->scsi_level = inq_result[2] & 0x07;
if (sdev->scsi_level >= 2 ||
(sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
sdev->scsi_level++;
sdev->sdev_target->scsi_level = sdev->scsi_level;
/*
* If SCSI-2 or lower, and if the transport requires it,
* store the LUN value in CDB[1].
*/
sdev->lun_in_cdb = 0;
if (sdev->scsi_level <= SCSI_2 &&
sdev->scsi_level != SCSI_UNKNOWN &&
!sdev->host->no_scsi2_lun_in_cdb)
sdev->lun_in_cdb = 1;
return 0;
}
/**
* scsi_add_lun - allocate and fully initialze a scsi_device
* @sdev: holds information to be stored in the new scsi_device
* @inq_result: holds the result of a previous INQUIRY to the LUN
* @bflags: black/white list flag
* @async: 1 if this device is being scanned asynchronously
*
* Description:
* Initialize the scsi_device @sdev. Optionally set fields based
* on values in *@bflags.
*
* Return:
* SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
* SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
**/
static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
blist_flags_t *bflags, int async)
{
int ret;
/*
* XXX do not save the inquiry, since it can change underneath us,
* save just vendor/model/rev.
*
* Rather than save it and have an ioctl that retrieves the saved
* value, have an ioctl that executes the same INQUIRY code used
* in scsi_probe_lun, let user level programs doing INQUIRY
* scanning run at their own risk, or supply a user level program
* that can correctly scan.
*/
/*
* Copy at least 36 bytes of INQUIRY data, so that we don't
* dereference unallocated memory when accessing the Vendor,
* Product, and Revision strings. Badly behaved devices may set
* the INQUIRY Additional Length byte to a small value, indicating
* these strings are invalid, but often they contain plausible data
* nonetheless. It doesn't matter if the device sent < 36 bytes
* total, since scsi_probe_lun() initializes inq_result with 0s.
*/
sdev->inquiry = kmemdup(inq_result,
max_t(size_t, sdev->inquiry_len, 36),
GFP_KERNEL);
if (sdev->inquiry == NULL)
return SCSI_SCAN_NO_RESPONSE;
sdev->vendor = (char *) (sdev->inquiry + 8);
sdev->model = (char *) (sdev->inquiry + 16);
sdev->rev = (char *) (sdev->inquiry + 32);
if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
/*
* sata emulation layer device. This is a hack to work around
* the SATL power management specifications which state that
* when the SATL detects the device has gone into standby
* mode, it shall respond with NOT READY.
*/
sdev->allow_restart = 1;
}
if (*bflags & BLIST_ISROM) {
sdev->type = TYPE_ROM;
sdev->removable = 1;
} else {
sdev->type = (inq_result[0] & 0x1f);
sdev->removable = (inq_result[1] & 0x80) >> 7;
/*
* some devices may respond with wrong type for
* well-known logical units. Force well-known type
* to enumerate them correctly.
*/
if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
sdev_printk(KERN_WARNING, sdev,
"%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
__func__, sdev->type, (unsigned int)sdev->lun);
sdev->type = TYPE_WLUN;
}
}
if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
/* RBC and MMC devices can return SCSI-3 compliance and yet
* still not support REPORT LUNS, so make them act as
* BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
* specifically set */
if ((*bflags & BLIST_REPORTLUN2) == 0)
*bflags |= BLIST_NOREPORTLUN;
}
/*
* For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
* spec says: The device server is capable of supporting the
* specified peripheral device type on this logical unit. However,
* the physical device is not currently connected to this logical
* unit.
*
* The above is vague, as it implies that we could treat 001 and
* 011 the same. Stay compatible with previous code, and create a
* scsi_device for a PQ of 1
*
* Don't set the device offline here; rather let the upper
* level drivers eval the PQ to decide whether they should
* attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
*/
sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
sdev->lockable = sdev->removable;
sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
if (sdev->scsi_level >= SCSI_3 ||
(sdev->inquiry_len > 56 && inq_result[56] & 0x04))
sdev->ppr = 1;
if (inq_result[7] & 0x60)
sdev->wdtr = 1;
if (inq_result[7] & 0x10)
sdev->sdtr = 1;
sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
"ANSI: %d%s\n", scsi_device_type(sdev->type),
sdev->vendor, sdev->model, sdev->rev,
sdev->inq_periph_qual, inq_result[2] & 0x07,
(inq_result[3] & 0x0f) == 1 ? " CCS" : "");
if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
!(*bflags & BLIST_NOTQ)) {
sdev->tagged_supported = 1;
sdev->simple_tags = 1;
}
/*
* Some devices (Texel CD ROM drives) have handshaking problems
* when used with the Seagate controllers. borken is initialized
* to 1, and then set it to 0 here.
*/
if ((*bflags & BLIST_BORKEN) == 0)
sdev->borken = 0;
if (*bflags & BLIST_NO_ULD_ATTACH)
sdev->no_uld_attach = 1;
/*
* Apparently some really broken devices (contrary to the SCSI
* standards) need to be selected without asserting ATN
*/
if (*bflags & BLIST_SELECT_NO_ATN)
sdev->select_no_atn = 1;
/*
* Maximum 512 sector transfer length
* broken RA4x00 Compaq Disk Array
*/
if (*bflags & BLIST_MAX_512)
blk_queue_max_hw_sectors(sdev->request_queue, 512);
/*
* Max 1024 sector transfer length for targets that report incorrect
* max/optimal lengths and relied on the old block layer safe default
*/
else if (*bflags & BLIST_MAX_1024)
blk_queue_max_hw_sectors(sdev->request_queue, 1024);
/*
* Some devices may not want to have a start command automatically
* issued when a device is added.
*/
if (*bflags & BLIST_NOSTARTONADD)
sdev->no_start_on_add = 1;
if (*bflags & BLIST_SINGLELUN)
scsi_target(sdev)->single_lun = 1;
sdev->use_10_for_rw = 1;
/* some devices don't like REPORT SUPPORTED OPERATION CODES