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linux/drivers/scsi/scsi_scan.c

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/*
* 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/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <asm/semaphore.h>
#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_devinfo.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_request.h>
#include <scsi/scsi_transport.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)
/*
* Prefix values for the SCSI id's (stored in driverfs 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 char *scsi_null_device_strs = "nullnullnullnull";
#define MAX_SCSI_LUNS 512
#ifdef CONFIG_SCSI_MULTI_LUN
static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
#else
static unsigned int max_scsi_luns = 1;
#endif
module_param_named(max_luns, max_scsi_luns, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_luns,
"last scsi LUN (should be between 1 and 2^32-1)");
/*
* max_scsi_report_luns: the maximum number of LUNS that will be
* returned from the REPORT LUNS command. 8 times this value must
* be allocated. In theory this could be up to an 8 byte value, but
* in practice, the maximum number of LUNs suppored by any device
* is about 16k.
*/
static unsigned int max_scsi_report_luns = 511;
module_param_named(max_report_luns, max_scsi_report_luns, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_report_luns,
"REPORT LUNS maximum number of LUNS received (should be"
" between 1 and 16384)");
static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
module_param_named(inq_timeout, scsi_inq_timeout, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(inq_timeout,
"Timeout (in seconds) waiting for devices to answer INQUIRY."
" Default is 5. Some non-compliant devices need more.");
/**
* scsi_unlock_floptical - unlock device via a special MODE SENSE command
* @sreq: used to send the command
* @result: area to store the result of the MODE SENSE
*
* Description:
* Send a vendor specific MODE SENSE (not a MODE SELECT) command using
* @sreq to unlock a device, storing the (unused) results into result.
* Called for BLIST_KEY devices.
**/
static void scsi_unlock_floptical(struct scsi_request *sreq,
unsigned char *result)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
printk(KERN_NOTICE "scsi: 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;
sreq->sr_cmd_len = 0;
sreq->sr_data_direction = DMA_FROM_DEVICE;
scsi_wait_req(sreq, scsi_cmd, result, 0x2a /* size */, SCSI_TIMEOUT, 3);
}
/**
* print_inquiry - printk the inquiry information
* @inq_result: printk this SCSI INQUIRY
*
* Description:
* printk the vendor, model, and other information found in the
* INQUIRY data in @inq_result.
*
* Notes:
* Remove this, and replace with a hotplug event that logs any
* relevant information.
**/
static void print_inquiry(unsigned char *inq_result)
{
int i;
printk(KERN_NOTICE " Vendor: ");
for (i = 8; i < 16; i++)
if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
printk("%c", inq_result[i]);
else
printk(" ");
printk(" Model: ");
for (i = 16; i < 32; i++)
if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
printk("%c", inq_result[i]);
else
printk(" ");
printk(" Rev: ");
for (i = 32; i < 36; i++)
if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
printk("%c", inq_result[i]);
else
printk(" ");
printk("\n");
i = inq_result[0] & 0x1f;
printk(KERN_NOTICE " Type: %s ",
i <
MAX_SCSI_DEVICE_CODE ? scsi_device_types[i] :
"Unknown ");
printk(" ANSI SCSI revision: %02x",
inq_result[2] & 0x07);
if ((inq_result[2] & 0x07) == 1 && (inq_result[3] & 0x0f) == 1)
printk(" CCS\n");
else
printk("\n");
}
/**
* scsi_alloc_sdev - allocate and setup a scsi_Device
*
* 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,
unsigned int lun, void *hostdata)
{
struct scsi_device *sdev;
int display_failure_msg = 1, ret;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
sdev = kmalloc(sizeof(*sdev) + shost->transportt->device_size,
GFP_ATOMIC);
if (!sdev)
goto out;
memset(sdev, 0, sizeof(*sdev));
sdev->vendor = scsi_null_device_strs;
sdev->model = scsi_null_device_strs;
sdev->rev = scsi_null_device_strs;
sdev->host = shost;
sdev->id = starget->id;
sdev->lun = lun;
sdev->channel = starget->channel;
sdev->sdev_state = SDEV_CREATED;
INIT_LIST_HEAD(&sdev->siblings);
INIT_LIST_HEAD(&sdev->same_target_siblings);
INIT_LIST_HEAD(&sdev->cmd_list);
INIT_LIST_HEAD(&sdev->starved_entry);
spin_lock_init(&sdev->list_lock);
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->request_queue = scsi_alloc_queue(sdev);
if (!sdev->request_queue) {
/* release fn is set up in scsi_sysfs_device_initialise, so
* have to free and put manually here */
put_device(&starget->dev);
goto out;
}
sdev->request_queue->queuedata = sdev;
scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
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:
transport_destroy_device(&sdev->sdev_gendev);
scsi_free_queue(sdev->request_queue);
put_device(&sdev->sdev_gendev);
out:
if (display_failure_msg)
printk(ALLOC_FAILURE_MSG, __FUNCTION__);
return NULL;
}
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);
}
int scsi_is_target_device(const struct device *dev)
{
return dev->release == scsi_target_dev_release;
}
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;
}
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 = kmalloc(size, GFP_ATOMIC);
struct scsi_target *found_target;
if (!starget) {
printk(KERN_ERR "%s: allocation failure\n", __FUNCTION__);
return NULL;
}
memset(starget, 0, size);
dev = &starget->dev;
device_initialize(dev);
starget->reap_ref = 1;
dev->parent = get_device(parent);
dev->release = scsi_target_dev_release;
sprintf(dev->bus_id, "target%d:%d:%d",
shost->host_no, channel, id);
starget->id = id;
starget->channel = channel;
INIT_LIST_HEAD(&starget->siblings);
INIT_LIST_HEAD(&starget->devices);
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(&starget->dev);
device_add(&starget->dev);
transport_add_device(&starget->dev);
return starget;
found:
found_target->reap_ref++;
spin_unlock_irqrestore(shost->host_lock, flags);
put_device(parent);
kfree(starget);
return found_target;
}
/**
* 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)
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
if (--starget->reap_ref == 0 && list_empty(&starget->devices)) {
list_del_init(&starget->siblings);
spin_unlock_irqrestore(shost->host_lock, flags);
device_del(&starget->dev);
transport_unregister_device(&starget->dev);
put_device(&starget->dev);
return;
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
/**
* scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
* @sreq: used to send the INQUIRY
* @inq_result: area to store the INQUIRY result
* @bflags: store any bflags found here
*
* Description:
* Probe the lun associated with @sreq using a standard SCSI INQUIRY;
*
* If the INQUIRY is successful, sreq->sr_result is zero and: the
* INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
* are copied to the Scsi_Device at @sreq->sr_device (sdev);
* any flags value is stored in *@bflags.
**/
static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
int *bflags)
{
struct scsi_device *sdev = sreq->sr_device; /* a bit ugly */
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
int first_inquiry_len, try_inquiry_len, next_inquiry_len;
int response_len = 0;
int pass, count;
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, printk(KERN_INFO "scsi scan: INQUIRY pass %d "
"to host %d channel %d id %d lun %d, length %d\n",
pass, sdev->host->host_no, sdev->channel,
sdev->id, sdev->lun, try_inquiry_len));
/* Each pass gets up to three chances to ignore Unit Attention */
for (count = 0; count < 3; ++count) {
memset(scsi_cmd, 0, 6);
scsi_cmd[0] = INQUIRY;
scsi_cmd[4] = (unsigned char) try_inquiry_len;
sreq->sr_cmd_len = 0;
sreq->sr_data_direction = DMA_FROM_DEVICE;
memset(inq_result, 0, try_inquiry_len);
scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result,
try_inquiry_len,
HZ/2 + HZ*scsi_inq_timeout, 3);
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
"with code 0x%x\n",
sreq->sr_result ? "failed" : "successful",
sreq->sr_result));
if (sreq->sr_result) {
/*
* 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 ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
scsi_request_normalize_sense(sreq, &sshdr)) {
if ((sshdr.sense_key == UNIT_ATTENTION) &&
((sshdr.asc == 0x28) ||
(sshdr.asc == 0x29)) &&
(sshdr.ascq == 0))
continue;
}
}
break;
}
if (sreq->sr_result == 0) {
response_len = (unsigned char) 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 (BLIST_INQUIRY_58 & *bflags)
next_inquiry_len = 58;
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) {
printk(KERN_INFO "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 (sreq->sr_result)
return;
/* 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.
*
* 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++;
return;
}
/**
* scsi_add_lun - allocate and fully initialze a Scsi_Device
* @sdevscan: holds information to be stored in the new Scsi_Device
* @sdevnew: store the address of the newly allocated Scsi_Device
* @inq_result: holds the result of a previous INQUIRY to the LUN
* @bflags: black/white list flag
*
* Description:
* Allocate and initialize a Scsi_Device matching sdevscan. Optionally
* set fields based on values in *@bflags. If @sdevnew is not
* NULL, store the address of the new Scsi_Device in *@sdevnew (needed
* when scanning a particular LUN).
*
* 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, char *inq_result, int *bflags)
{
/*
* 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.
*/
sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
if (sdev->inquiry == NULL) {
return SCSI_SCAN_NO_RESPONSE;
}
memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
sdev->vendor = (char *) (sdev->inquiry + 8);
sdev->model = (char *) (sdev->inquiry + 16);
sdev->rev = (char *) (sdev->inquiry + 32);
if (*bflags & BLIST_ISROM) {
/*
* It would be better to modify sdev->type, and set
* sdev->removable, but then the print_inquiry() output
* would not show TYPE_ROM; if print_inquiry() is removed
* the issue goes away.
*/
inq_result[0] = TYPE_ROM;
inq_result[1] |= 0x80; /* removable */
} else if (*bflags & BLIST_NO_ULD_ATTACH)
sdev->no_uld_attach = 1;
switch (sdev->type = (inq_result[0] & 0x1f)) {
case TYPE_TAPE:
case TYPE_DISK:
case TYPE_PRINTER:
case TYPE_MOD:
case TYPE_PROCESSOR:
case TYPE_SCANNER:
case TYPE_MEDIUM_CHANGER:
case TYPE_ENCLOSURE:
case TYPE_COMM:
sdev->writeable = 1;
break;
case TYPE_WORM:
case TYPE_ROM:
sdev->writeable = 0;
break;
default:
printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
}
print_inquiry(inq_result);
/*
* 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->removable = (0x80 & inq_result[1]) >> 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;
sprintf(sdev->devfs_name, "scsi/host%d/bus%d/target%d/lun%d",
sdev->host->host_no, sdev->channel,
sdev->id, sdev->lun);
/*
* End driverfs/devfs code.
*/
if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
!(*bflags & BLIST_NOTQ))
sdev->tagged_supported = 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;
/*
* 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;
/*
* 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)
sdev->single_lun = 1;
sdev->use_10_for_rw = 1;
if (*bflags & BLIST_MS_SKIP_PAGE_08)
sdev->skip_ms_page_8 = 1;
if (*bflags & BLIST_MS_SKIP_PAGE_3F)
sdev->skip_ms_page_3f = 1;
if (*bflags & BLIST_USE_10_BYTE_MS)
sdev->use_10_for_ms = 1;
/* set the device running here so that slave configure
* may do I/O */
scsi_device_set_state(sdev, SDEV_RUNNING);
if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
sdev->use_192_bytes_for_3f = 1;
if (*bflags & BLIST_NOT_LOCKABLE)
sdev->lockable = 0;
if (*bflags & BLIST_RETRY_HWERROR)
sdev->retry_hwerror = 1;
transport_configure_device(&sdev->sdev_gendev);
if (sdev->host->hostt->slave_configure)
sdev->host->hostt->slave_configure(sdev);
/*
* Ok, the device is now all set up, we can
* register it and tell the rest of the kernel
* about it.
*/
scsi_sysfs_add_sdev(sdev);
return SCSI_SCAN_LUN_PRESENT;
}
/**
* scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
* @starget: pointer to target device structure
* @lun: LUN of target device
* @sdevscan: probe the LUN corresponding to this Scsi_Device
* @sdevnew: store the value of any new Scsi_Device allocated
* @bflagsp: store bflags here if not NULL
*
* Description:
* Call scsi_probe_lun, if a LUN with an attached device is found,
* allocate and set it up by calling scsi_add_lun.
*
* Return:
* SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
* SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
* attached at the LUN
* SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
**/
static int scsi_probe_and_add_lun(struct scsi_target *starget,
uint lun, int *bflagsp,
struct scsi_device **sdevp, int rescan,
void *hostdata)
{
struct scsi_device *sdev;
struct scsi_request *sreq;
unsigned char *result;
int bflags, res = SCSI_SCAN_NO_RESPONSE;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
/*
* The rescan flag is used as an optimization, the first scan of a
* host adapter calls into here with rescan == 0.
*/
if (rescan) {
sdev = scsi_device_lookup_by_target(starget, lun);
if (sdev) {
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
"scsi scan: device exists on %s\n",
sdev->sdev_gendev.bus_id));
if (sdevp)
*sdevp = sdev;
else
scsi_device_put(sdev);
if (bflagsp)
*bflagsp = scsi_get_device_flags(sdev,
sdev->vendor,
sdev->model);
return SCSI_SCAN_LUN_PRESENT;
}
}
sdev = scsi_alloc_sdev(starget, lun, hostdata);
if (!sdev)
goto out;
sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
if (!sreq)
goto out_free_sdev;
result = kmalloc(256, GFP_ATOMIC |
(shost->unchecked_isa_dma) ? __GFP_DMA : 0);
if (!result)
goto out_free_sreq;
scsi_probe_lun(sreq, result, &bflags);
if (sreq->sr_result)
goto out_free_result;
/*
* result contains valid SCSI INQUIRY data.
*/
if ((result[0] >> 5) == 3) {
/*
* For a Peripheral qualifier 3 (011b), the SCSI
* spec says: The device server is not capable of
* supporting a physical device on this logical
* unit.
*
* For disks, this implies that there is no
* logical disk configured at sdev->lun, but there
* is a target id responding.
*/
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
"scsi scan: peripheral qualifier of 3,"
" no device added\n"));
res = SCSI_SCAN_TARGET_PRESENT;
goto out_free_result;
}
res = scsi_add_lun(sdev, result, &bflags);
if (res == SCSI_SCAN_LUN_PRESENT) {
if (bflags & BLIST_KEY) {
sdev->lockable = 0;
scsi_unlock_floptical(sreq, result);
}
if (bflagsp)
*bflagsp = bflags;
}
out_free_result:
kfree(result);
out_free_sreq:
scsi_release_request(sreq);
out_free_sdev:
if (res == SCSI_SCAN_LUN_PRESENT) {
if (sdevp) {
scsi_device_get(sdev);
*sdevp = sdev;
}
} else {
if (sdev->host->hostt->slave_destroy)
sdev->host->hostt->slave_destroy(sdev);
transport_destroy_device(&sdev->sdev_gendev);
put_device(&sdev->sdev_gendev);
}
out:
return res;
}
/**
* scsi_sequential_lun_scan - sequentially scan a SCSI target
* @starget: pointer to target structure to scan
* @bflags: black/white list flag for LUN 0
* @lun0_res: result of scanning LUN 0
*
* Description:
* Generally, scan from LUN 1 (LUN 0 is assumed to already have been
* scanned) to some maximum lun until a LUN is found with no device
* attached. Use the bflags to figure out any oddities.
*
* Modifies sdevscan->lun.
**/
static void scsi_sequential_lun_scan(struct scsi_target *starget,
int bflags, int lun0_res, int scsi_level,
int rescan)
{
unsigned int sparse_lun, lun, max_dev_lun;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
"%s\n", starget->dev.bus_id));
max_dev_lun = min(max_scsi_luns, shost->max_lun);
/*
* If this device is known to support sparse multiple units,
* override the other settings, and scan all of them. Normally,
* SCSI-3 devices should be scanned via the REPORT LUNS.
*/
if (bflags & BLIST_SPARSELUN) {
max_dev_lun = shost->max_lun;
sparse_lun = 1;
} else
sparse_lun = 0;
/*
* If not sparse lun and no device attached at LUN 0 do not scan
* any further.
*/
if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
return;
/*
* If less than SCSI_1_CSS, and no special lun scaning, stop
* scanning; this matches 2.4 behaviour, but could just be a bug
* (to continue scanning a SCSI_1_CSS device).
*
* This test is broken. We might not have any device on lun0 for
* a sparselun device, and if that's the case then how would we
* know the real scsi_level, eh? It might make sense to just not
* scan any SCSI_1 device for non-0 luns, but that check would best
* go into scsi_alloc_sdev() and just have it return null when asked
* to alloc an sdev for lun > 0 on an already found SCSI_1 device.
*
if ((sdevscan->scsi_level < SCSI_1_CCS) &&
((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
== 0))
return;
*/
/*
* If this device is known to support multiple units, override
* the other settings, and scan all of them.
*/
if (bflags & BLIST_FORCELUN)
max_dev_lun = shost->max_lun;
/*
* REGAL CDC-4X: avoid hang after LUN 4
*/
if (bflags & BLIST_MAX5LUN)
max_dev_lun = min(5U, max_dev_lun);
/*
* Do not scan SCSI-2 or lower device past LUN 7, unless
* BLIST_LARGELUN.
*/
if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
max_dev_lun = min(8U, max_dev_lun);
/*
* We have already scanned LUN 0, so start at LUN 1. Keep scanning
* until we reach the max, or no LUN is found and we are not
* sparse_lun.
*/
for (lun = 1; lun < max_dev_lun; ++lun)
if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
NULL) != SCSI_SCAN_LUN_PRESENT) &&
!sparse_lun)
return;
}
/**
* scsilun_to_int: convert a scsi_lun to an int
* @scsilun: struct scsi_lun to be converted.
*
* Description:
* Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
* integer, and return the result. The caller must check for
* truncation before using this function.
*
* Notes:
* The struct scsi_lun is assumed to be four levels, with each level
* effectively containing a SCSI byte-ordered (big endian) short; the
* addressing bits of each level are ignored (the highest two bits).
* For a description of the LUN format, post SCSI-3 see the SCSI
* Architecture Model, for SCSI-3 see the SCSI Controller Commands.
*
* Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
* the integer: 0x0b030a04
**/
static int scsilun_to_int(struct scsi_lun *scsilun)
{
int i;
unsigned int lun;
lun = 0;
for (i = 0; i < sizeof(lun); i += 2)
lun = lun | (((scsilun->scsi_lun[i] << 8) |
scsilun->scsi_lun[i + 1]) << (i * 8));
return lun;
}
/**
* scsi_report_lun_scan - Scan using SCSI REPORT LUN results
* @sdevscan: scan the host, channel, and id of this Scsi_Device
*
* Description:
* If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
* command, and scan the resulting list of LUNs by calling
* scsi_probe_and_add_lun.
*
* Modifies sdevscan->lun.
*
* Return:
* 0: scan completed (or no memory, so further scanning is futile)
* 1: no report lun scan, or not configured
**/
static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
int rescan)
{
char devname[64];
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
unsigned int length;
unsigned int lun;
unsigned int num_luns;
unsigned int retries;
struct scsi_lun *lunp, *lun_data;
struct scsi_request *sreq;
u8 *data;
struct scsi_sense_hdr sshdr;
struct scsi_target *starget = scsi_target(sdev);
/*
* Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
* Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
* support more than 8 LUNs.
*/
if ((bflags & BLIST_NOREPORTLUN) ||
sdev->scsi_level < SCSI_2 ||
(sdev->scsi_level < SCSI_3 &&
(!(bflags & BLIST_REPORTLUN2) || sdev->host->max_lun <= 8)) )
return 1;
if (bflags & BLIST_NOLUN)
return 0;
sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
if (!sreq)
goto out;
sprintf(devname, "host %d channel %d id %d",
sdev->host->host_no, sdev->channel, sdev->id);
/*
* Allocate enough to hold the header (the same size as one scsi_lun)
* plus the max number of luns we are requesting.
*
* Reallocating and trying again (with the exact amount we need)
* would be nice, but then we need to somehow limit the size
* allocated based on the available memory and the limits of
* kmalloc - we don't want a kmalloc() failure of a huge value to
* prevent us from finding any LUNs on this target.
*/
length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
lun_data = kmalloc(length, GFP_ATOMIC |
(sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
if (!lun_data)
goto out_release_request;
scsi_cmd[0] = REPORT_LUNS;
/*
* bytes 1 - 5: reserved, set to zero.
*/
memset(&scsi_cmd[1], 0, 5);
/*
* bytes 6 - 9: length of the command.
*/
scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
scsi_cmd[9] = (unsigned char) length & 0xff;
scsi_cmd[10] = 0; /* reserved */
scsi_cmd[11] = 0; /* control */
sreq->sr_cmd_len = 0;
sreq->sr_data_direction = DMA_FROM_DEVICE;
/*
* We can get a UNIT ATTENTION, for example a power on/reset, so
* retry a few times (like sd.c does for TEST UNIT READY).
* Experience shows some combinations of adapter/devices get at
* least two power on/resets.
*
* Illegal requests (for devices that do not support REPORT LUNS)
* should come through as a check condition, and will not generate
* a retry.
*/
for (retries = 0; retries < 3; retries++) {
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
" REPORT LUNS to %s (try %d)\n", devname,
retries));
scsi_wait_req(sreq, scsi_cmd, lun_data, length,
SCSI_TIMEOUT + 4*HZ, 3);
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
" %s (try %d) result 0x%x\n", sreq->sr_result
? "failed" : "successful", retries,
sreq->sr_result));
if (sreq->sr_result == 0)
break;
else if (scsi_request_normalize_sense(sreq, &sshdr)) {
if (sshdr.sense_key != UNIT_ATTENTION)
break;
}
}
if (sreq->sr_result) {
/*
* The device probably does not support a REPORT LUN command
*/
kfree(lun_data);
scsi_release_request(sreq);
return 1;
}
scsi_release_request(sreq);
/*
* Get the length from the first four bytes of lun_data.
*/
data = (u8 *) lun_data->scsi_lun;
length = ((data[0] << 24) | (data[1] << 16) |
(data[2] << 8) | (data[3] << 0));
num_luns = (length / sizeof(struct scsi_lun));
if (num_luns > max_scsi_report_luns) {
printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
" of %d luns reported, try increasing"
" max_scsi_report_luns.\n", devname,
max_scsi_report_luns, num_luns);
num_luns = max_scsi_report_luns;
}
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUN scan of"
" host %d channel %d id %d\n", sdev->host->host_no,
sdev->channel, sdev->id));
/*
* Scan the luns in lun_data. The entry at offset 0 is really
* the header, so start at 1 and go up to and including num_luns.
*/
for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
lun = scsilun_to_int(lunp);
/*
* Check if the unused part of lunp is non-zero, and so
* does not fit in lun.
*/
if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
int i;
/*
* Output an error displaying the LUN in byte order,
* this differs from what linux would print for the
* integer LUN value.
*/
printk(KERN_WARNING "scsi: %s lun 0x", devname);
data = (char *)lunp->scsi_lun;
for (i = 0; i < sizeof(struct scsi_lun); i++)
printk("%02x", data[i]);
printk(" has a LUN larger than currently supported.\n");
} else if (lun == 0) {
/*
* LUN 0 has already been scanned.
*/
} else if (lun > sdev->host->max_lun) {
printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
" than allowed by the host adapter\n",
devname, lun);
} else {
int res;
res = scsi_probe_and_add_lun(starget,
lun, NULL, NULL, rescan, NULL);
if (res == SCSI_SCAN_NO_RESPONSE) {
/*
* Got some results, but now none, abort.
*/
printk(KERN_ERR "scsi: Unexpected response"
" from %s lun %d while scanning, scan"
" aborted\n", devname, lun);
break;
}
}
}
kfree(lun_data);
return 0;
out_release_request:
scsi_release_request(sreq);
out:
/*
* We are out of memory, don't try scanning any further.
*/
printk(ALLOC_FAILURE_MSG, __FUNCTION__);
return 0;
}
struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
uint id, uint lun, void *hostdata)
{
struct scsi_device *sdev;
struct device *parent = &shost->shost_gendev;
int res;
struct scsi_target *starget = scsi_alloc_target(parent, channel, id);
if (!starget)
return ERR_PTR(-ENOMEM);
down(&shost->scan_mutex);
res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
if (res != SCSI_SCAN_LUN_PRESENT)
sdev = ERR_PTR(-ENODEV);
up(&shost->scan_mutex);
scsi_target_reap(starget);
put_device(&starget->dev);
return sdev;
}
EXPORT_SYMBOL(__scsi_add_device);
void scsi_rescan_device(struct device *dev)
{
struct scsi_driver *drv;
if (!dev->driver)
return;
drv = to_scsi_driver(dev->driver);
if (try_module_get(drv->owner)) {
if (drv->rescan)
drv->rescan(dev);
module_put(drv->owner);
}
}
EXPORT_SYMBOL(scsi_rescan_device);
/**
* scsi_scan_target - scan a target id, possibly including all LUNs on the
* target.
* @sdevsca: Scsi_Device handle for scanning
* @shost: host to scan
* @channel: channel to scan
* @id: target id to scan
*
* Description:
* Scan the target id on @shost, @channel, and @id. Scan at least LUN
* 0, and possibly all LUNs on the target id.
*
* Use the pre-allocated @sdevscan as a handle for the scanning. This
* function sets sdevscan->host, sdevscan->id and sdevscan->lun; the
* scanning functions modify sdevscan->lun.
*
* First try a REPORT LUN scan, if that does not scan the target, do a
* sequential scan of LUNs on the target id.
**/
void scsi_scan_target(struct device *parent, unsigned int channel,
unsigned int id, unsigned int lun, int rescan)
{
struct Scsi_Host *shost = dev_to_shost(parent);
int bflags = 0;
int res;
struct scsi_device *sdev = NULL;
struct scsi_target *starget;
if (shost->this_id == id)
/*
* Don't scan the host adapter
*/
return;
starget = scsi_alloc_target(parent, channel, id);
if (!starget)
return;
get_device(&starget->dev);
if (lun != SCAN_WILD_CARD) {
/*
* Scan for a specific host/chan/id/lun.
*/
scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
goto out_reap;
}
/*
* Scan LUN 0, if there is some response, scan further. Ideally, we
* would not configure LUN 0 until all LUNs are scanned.
*/
res = scsi_probe_and_add_lun(starget, 0, &bflags, &sdev, rescan, NULL);
if (res == SCSI_SCAN_LUN_PRESENT) {
if (scsi_report_lun_scan(sdev, bflags, rescan) != 0)
/*
* The REPORT LUN did not scan the target,
* do a sequential scan.
*/
scsi_sequential_lun_scan(starget, bflags,
res, sdev->scsi_level, rescan);
} else if (res == SCSI_SCAN_TARGET_PRESENT) {
/*
* There's a target here, but lun 0 is offline so we
* can't use the report_lun scan. Fall back to a
* sequential lun scan with a bflags of SPARSELUN and
* a default scsi level of SCSI_2
*/
scsi_sequential_lun_scan(starget, BLIST_SPARSELUN,
SCSI_SCAN_TARGET_PRESENT, SCSI_2, rescan);
}
if (sdev)
scsi_device_put(sdev);
out_reap:
/* now determine if the target has any children at all
* and if not, nuke it */
scsi_target_reap(starget);
put_device(&starget->dev);
}
EXPORT_SYMBOL(scsi_scan_target);
static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
unsigned int id, unsigned int lun, int rescan)
{
uint order_id;
if (id == SCAN_WILD_CARD)
for (id = 0; id < shost->max_id; ++id) {
/*
* XXX adapter drivers when possible (FCP, iSCSI)
* could modify max_id to match the current max,
* not the absolute max.
*
* XXX add a shost id iterator, so for example,
* the FC ID can be the same as a target id
* without a huge overhead of sparse id's.
*/
if (shost->reverse_ordering)
/*
* Scan from high to low id.
*/
order_id = shost->max_id - id - 1;
else
order_id = id;
scsi_scan_target(&shost->shost_gendev, channel, order_id, lun, rescan);
}
else
scsi_scan_target(&shost->shost_gendev, channel, id, lun, rescan);
}
int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
unsigned int id, unsigned int lun, int rescan)
{
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "%s: <%u:%u:%u:%u>\n",
__FUNCTION__, shost->host_no, channel, id, lun));
if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
return -EINVAL;
down(&shost->scan_mutex);
if (channel == SCAN_WILD_CARD)
for (channel = 0; channel <= shost->max_channel; channel++)
scsi_scan_channel(shost, channel, id, lun, rescan);
else
scsi_scan_channel(shost, channel, id, lun, rescan);
up(&shost->scan_mutex);
return 0;
}
/**
* scsi_scan_host - scan the given adapter
* @shost: adapter to scan
**/
void scsi_scan_host(struct Scsi_Host *shost)
{
scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
SCAN_WILD_CARD, 0);
}
EXPORT_SYMBOL(scsi_scan_host);
/**
* scsi_scan_single_target - scan the given SCSI target
* @shost: adapter to scan
* @chan: channel to scan
* @id: target id to scan
**/
void scsi_scan_single_target(struct Scsi_Host *shost,
unsigned int chan, unsigned int id)
{
scsi_scan_host_selected(shost, chan, id, SCAN_WILD_CARD, 1);
}
EXPORT_SYMBOL(scsi_scan_single_target);
void scsi_forget_host(struct Scsi_Host *shost)
{
struct scsi_target *starget, *tmp;
unsigned long flags;
/*
* Ok, this look a bit strange. We always look for the first device
* on the list as scsi_remove_device removes them from it - thus we
* also have to release the lock.
* We don't need to get another reference to the device before
* releasing the lock as we already own the reference from
* scsi_register_device that's release in scsi_remove_device. And
* after that we don't look at sdev anymore.
*/
spin_lock_irqsave(shost->host_lock, flags);
list_for_each_entry_safe(starget, tmp, &shost->__targets, siblings) {
spin_unlock_irqrestore(shost->host_lock, flags);
scsi_remove_target(&starget->dev);
spin_lock_irqsave(shost->host_lock, flags);
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
/*
* Function: scsi_get_host_dev()
*
* Purpose: Create a Scsi_Device that points to the host adapter itself.
*
* Arguments: SHpnt - Host that needs a Scsi_Device
*
* Lock status: None assumed.
*
* Returns: The Scsi_Device or NULL
*
* Notes:
* Attach a single Scsi_Device to the Scsi_Host - this should
* be made to look like a "pseudo-device" that points to the
* HA itself.
*
* Note - this device is not accessible from any high-level
* drivers (including generics), which is probably not
* optimal. We can add hooks later to attach
*/
struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
{
struct scsi_device *sdev;
struct scsi_target *starget;
starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
if (!starget)
return NULL;
sdev = scsi_alloc_sdev(starget, 0, NULL);
if (sdev) {
sdev->sdev_gendev.parent = get_device(&starget->dev);
sdev->borken = 0;
}
put_device(&starget->dev);
return sdev;
}
EXPORT_SYMBOL(scsi_get_host_dev);
/*
* Function: scsi_free_host_dev()
*
* Purpose: Free a scsi_device that points to the host adapter itself.
*
* Arguments: SHpnt - Host that needs a Scsi_Device
*
* Lock status: None assumed.
*
* Returns: Nothing
*
* Notes:
*/
void scsi_free_host_dev(struct scsi_device *sdev)
{
BUG_ON(sdev->id != sdev->host->this_id);
if (sdev->host->hostt->slave_destroy)
sdev->host->hostt->slave_destroy(sdev);
transport_destroy_device(&sdev->sdev_gendev);
put_device(&sdev->sdev_gendev);
}
EXPORT_SYMBOL(scsi_free_host_dev);
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