kernel-fxtec-pro1x/drivers/scsi/scsi_scan.c
Arjan van de Ven d4d5291c8c driver synchronization: make scsi_wait_scan more advanced
There is currently only one way for userspace to say "wait for my storage
device to get ready for the modules I just loaded": to load the
scsi_wait_scan module. Expectations of userspace are that once this
module is loaded, all the (storage) devices for which the drivers
were loaded before the module load are present.

Now, there are some issues with the implementation, and the async
stuff got caught in the middle of this: The existing code only
waits for the scsy async probing to finish, but it did not take
into account at all that probing might not have begun yet.
(Russell ran into this problem on his computer and the fix works for him)

This patch fixes this more thoroughly than the previous "fix", which
had some bad side effects (namely, for kernel code that wanted to wait for
the scsi scan it would also do an async sync, which would deadlock if you did
it from async context already.. there's a report about that on lkml):
The patch makes the module first wait for all device driver probes, and then it
will wait for the scsi parallel scan to finish.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-21 19:40:00 -07:00

1946 lines
54 KiB
C

/*
* 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 <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_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 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
#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, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_luns,
"last scsi LUN (should be between 1 and 2^32-1)");
#ifdef CONFIG_SCSI_SCAN_ASYNC
#define SCSI_SCAN_TYPE_DEFAULT "async"
#else
#define SCSI_SCAN_TYPE_DEFAULT "sync"
#endif
static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT;
module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO);
MODULE_PARM_DESC(scan, "sync, async or none");
/*
* 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, uint, 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, uint, 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.");
/* 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_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;
}
/* Only exported for the benefit of scsi_wait_scan */
EXPORT_SYMBOL_GPL(scsi_complete_async_scans);
#ifndef MODULE
/*
* For async scanning we need to wait for all the scans to complete before
* trying to mount the root fs. Otherwise non-modular drivers may not be ready
* yet.
*/
late_initcall(scsi_complete_async_scans);
#endif
/**
* 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];
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;
scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
SCSI_TIMEOUT, 3, NULL);
}
/**
* 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,
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);
extern void scsi_evt_thread(struct work_struct *work);
sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
GFP_ATOMIC);
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->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);
INIT_LIST_HEAD(&sdev->event_list);
spin_lock_init(&sdev->list_lock);
INIT_WORK(&sdev->event_work, scsi_evt_thread);
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);
kfree(sdev);
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:
scsi_device_set_state(sdev, SDEV_DEL);
transport_destroy_device(&sdev->sdev_gendev);
put_device(&sdev->sdev_gendev);
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;
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_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;
starget = kzalloc(size, GFP_KERNEL);
if (!starget) {
printk(KERN_ERR "%s: allocation failure\n", __func__);
return NULL;
}
dev = &starget->dev;
device_initialize(dev);
starget->reap_ref = 1;
dev->parent = get_device(parent);
dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
#ifndef CONFIG_SYSFS_DEPRECATED
dev->bus = &scsi_bus_type;
#endif
dev->type = &scsi_target_type;
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;
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) {
dev_printk(KERN_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:
found_target->reap_ref++;
spin_unlock_irqrestore(shost->host_lock, flags);
if (found_target->state != STARGET_DEL) {
put_device(parent);
kfree(starget);
return found_target;
}
/* Unfortunately, we found a dying target; need to
* wait until it's dead before we can get a new one */
put_device(&found_target->dev);
flush_scheduled_work();
goto retry;
}
static void scsi_target_reap_usercontext(struct work_struct *work)
{
struct scsi_target *starget =
container_of(work, struct scsi_target, ew.work);
transport_remove_device(&starget->dev);
device_del(&starget->dev);
scsi_target_destroy(starget);
}
/**
* 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;
enum scsi_target_state state;
int empty;
spin_lock_irqsave(shost->host_lock, flags);
state = starget->state;
empty = --starget->reap_ref == 0 &&
list_empty(&starget->devices) ? 1 : 0;
spin_unlock_irqrestore(shost->host_lock, flags);
if (!empty)
return;
BUG_ON(state == STARGET_DEL);
starget->state = STARGET_DEL;
if (state == STARGET_CREATED)
scsi_target_destroy(starget);
else
execute_in_process_context(scsi_target_reap_usercontext,
&starget->ew);
}
/**
* 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.
**/
static void 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 = ' ';
}
}
/**
* 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, int *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, printk(KERN_INFO "scsi scan: INQUIRY %s "
"with code 0x%x\n",
result ? "failed" : "successful", result));
if (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(result) & DRIVER_SENSE) &&
scsi_sense_valid(&sshdr)) {
if ((sshdr.sense_key == UNIT_ATTENTION) &&
((sshdr.asc == 0x28) ||
(sshdr.asc == 0x29)) &&
(sshdr.ascq == 0))
continue;
}
} else {
/*
* 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) {
sanitize_inquiry_string(&inq_result[8], 8);
sanitize_inquiry_string(&inq_result[16], 16);
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 (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 (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) {
printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
" using 36\n", sdev->inquiry_len);
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;
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,
int *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_ATOMIC);
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 (*bflags & BLIST_ISROM) {
sdev->type = TYPE_ROM;
sdev->removable = 1;
} else {
sdev->type = (inq_result[0] & 0x1f);
sdev->removable = (inq_result[1] & 0x80) >> 7;
}
switch (sdev->type) {
case TYPE_RBC:
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:
case TYPE_RAID:
case TYPE_OSD:
sdev->writeable = 1;
break;
case TYPE_ROM:
case TYPE_WORM:
sdev->writeable = 0;
break;
default:
printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
}
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;
/*
* 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_sectors(sdev->request_queue, 512);
/*
* 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;
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 */
ret = scsi_device_set_state(sdev, SDEV_RUNNING);
if (ret) {
ret = scsi_device_set_state(sdev, SDEV_BLOCK);
if (ret) {
sdev_printk(KERN_ERR, sdev,
"in wrong state %s to complete scan\n",
scsi_device_state_name(sdev->sdev_state));
return SCSI_SCAN_NO_RESPONSE;
}
}
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) {
ret = sdev->host->hostt->slave_configure(sdev);
if (ret) {
/*
* if LLDD reports slave not present, don't clutter
* console with alloc failure messages
*/
if (ret != -ENXIO) {
sdev_printk(KERN_ERR, sdev,
"failed to configure device\n");
}
return SCSI_SCAN_NO_RESPONSE;
}
}
/*
* Ok, the device is now all set up, we can
* register it and tell the rest of the kernel
* about it.
*/
if (!async && scsi_sysfs_add_sdev(sdev) != 0)
return SCSI_SCAN_NO_RESPONSE;
return SCSI_SCAN_LUN_PRESENT;
}
static inline void scsi_destroy_sdev(struct scsi_device *sdev)
{
scsi_device_set_state(sdev, SDEV_DEL);
if (sdev->host->hostt->slave_destroy)
sdev->host->hostt->slave_destroy(sdev);
transport_destroy_device(&sdev->sdev_gendev);
put_device(&sdev->sdev_gendev);
}
#ifdef CONFIG_SCSI_LOGGING
/**
* scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
* @buf: Output buffer with at least end-first+1 bytes of space
* @inq: Inquiry buffer (input)
* @first: Offset of string into inq
* @end: Index after last character in inq
*/
static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
unsigned first, unsigned end)
{
unsigned term = 0, idx;
for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
if (inq[idx+first] > ' ') {
buf[idx] = inq[idx+first];
term = idx+1;
} else {
buf[idx] = ' ';
}
}
buf[term] = 0;
return buf;
}
#endif
/**
* 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
* @bflagsp: store bflags here if not NULL
* @sdevp: probe the LUN corresponding to this scsi_device
* @rescan: if nonzero skip some code only needed on first scan
* @hostdata: passed to scsi_alloc_sdev()
*
* 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;
unsigned char *result;
int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
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.
*/
sdev = scsi_device_lookup_by_target(starget, lun);
if (sdev) {
if (rescan || !scsi_device_created(sdev)) {
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
"scsi scan: device exists on %s\n",
dev_name(&sdev->sdev_gendev)));
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;
}
scsi_device_put(sdev);
} else
sdev = scsi_alloc_sdev(starget, lun, hostdata);
if (!sdev)
goto out;
result = kmalloc(result_len, GFP_ATOMIC |
((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
if (!result)
goto out_free_sdev;
if (scsi_probe_lun(sdev, result, result_len, &bflags))
goto out_free_result;
if (bflagsp)
*bflagsp = bflags;
/*
* result contains valid SCSI INQUIRY data.
*/
if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
/*
* 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(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
" peripheral qualifier of 3, device not"
" added\n"))
if (lun == 0) {
SCSI_LOG_SCAN_BUS(1, {
unsigned char vend[9];
unsigned char mod[17];
sdev_printk(KERN_INFO, sdev,
"scsi scan: consider passing scsi_mod."
"dev_flags=%s:%s:0x240 or 0x1000240\n",
scsi_inq_str(vend, result, 8, 16),
scsi_inq_str(mod, result, 16, 32));
});
}
res = SCSI_SCAN_TARGET_PRESENT;
goto out_free_result;
}
/*
* Some targets may set slight variations of PQ and PDT to signal
* that no LUN is present, so don't add sdev in these cases.
* Two specific examples are:
* 1) NetApp targets: return PQ=1, PDT=0x1f
* 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
* in the UFI 1.0 spec (we cannot rely on reserved bits).
*
* References:
* 1) SCSI SPC-3, pp. 145-146
* PQ=1: "A peripheral device having the specified peripheral
* device type is not connected to this logical unit. However, the
* device server is capable of supporting the specified peripheral
* device type on this logical unit."
* PDT=0x1f: "Unknown or no device type"
* 2) USB UFI 1.0, p. 20
* PDT=00h Direct-access device (floppy)
* PDT=1Fh none (no FDD connected to the requested logical unit)
*/
if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
(result[0] & 0x1f) == 0x1f &&
!scsi_is_wlun(lun)) {
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
"scsi scan: peripheral device type"
" of 31, no device added\n"));
res = SCSI_SCAN_TARGET_PRESENT;
goto out_free_result;
}
res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
if (res == SCSI_SCAN_LUN_PRESENT) {
if (bflags & BLIST_KEY) {
sdev->lockable = 0;
scsi_unlock_floptical(sdev, result);
}
}
out_free_result:
kfree(result);
out_free_sdev:
if (res == SCSI_SCAN_LUN_PRESENT) {
if (sdevp) {
if (scsi_device_get(sdev) == 0) {
*sdevp = sdev;
} else {
__scsi_remove_device(sdev);
res = SCSI_SCAN_NO_RESPONSE;
}
}
} else
scsi_destroy_sdev(sdev);
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
* @scsi_level: Which version of the standard does this device adhere to
* @rescan: passed to scsi_probe_add_lun()
*
* 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 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", dev_name(&starget->dev)));
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 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
**/
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;
}
EXPORT_SYMBOL(scsilun_to_int);
/**
* int_to_scsilun: reverts an int into a scsi_lun
* @lun: integer to be reverted
* @scsilun: struct scsi_lun to be set.
*
* Description:
* Reverts the functionality of the scsilun_to_int, which packed
* an 8-byte lun value into an int. This routine unpacks the int
* back into the lun value.
* Note: the scsilun_to_int() routine does not truly handle all
* 8bytes of the lun value. This functions restores only as much
* as was set by the routine.
*
* Notes:
* Given an integer : 0x0b030a04, this function returns a
* scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
*
**/
void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
{
int i;
memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
for (i = 0; i < sizeof(lun); i += 2) {
scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
scsilun->scsi_lun[i+1] = lun & 0xFF;
lun = lun >> 16;
}
}
EXPORT_SYMBOL(int_to_scsilun);
/**
* scsi_report_lun_scan - Scan using SCSI REPORT LUN results
* @starget: which target
* @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
* @rescan: nonzero if we can skip code only needed on first scan
*
* Description:
* Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
* Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
*
* If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
* LUNs even if it's older than SCSI-3.
* If BLIST_NOREPORTLUN is set, return 1 always.
* If BLIST_NOLUN is set, return 0 always.
*
* Return:
* 0: scan completed (or no memory, so further scanning is futile)
* 1: could not scan with REPORT LUN
**/
static int scsi_report_lun_scan(struct scsi_target *starget, 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;
int result;
struct scsi_lun *lunp, *lun_data;
u8 *data;
struct scsi_sense_hdr sshdr;
struct scsi_device *sdev;
struct Scsi_Host *shost = dev_to_shost(&starget->dev);
int ret = 0;
/*
* 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)
return 1;
if (starget->scsi_level < SCSI_2 &&
starget->scsi_level != SCSI_UNKNOWN)
return 1;
if (starget->scsi_level < SCSI_3 &&
(!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
return 1;
if (bflags & BLIST_NOLUN)
return 0;
if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
sdev = scsi_alloc_sdev(starget, 0, NULL);
if (!sdev)
return 0;
if (scsi_device_get(sdev))
return 0;
}
sprintf(devname, "host %d channel %d id %d",
shost->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) {
printk(ALLOC_FAILURE_MSG, __func__);
goto out;
}
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 */
/*
* 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));
result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
lun_data, length, &sshdr,
SCSI_TIMEOUT + 4 * HZ, 3, NULL);
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
" %s (try %d) result 0x%x\n", result
? "failed" : "successful", retries, result));
if (result == 0)
break;
else if (scsi_sense_valid(&sshdr)) {
if (sshdr.sense_key != UNIT_ATTENTION)
break;
}
}
if (result) {
/*
* The device probably does not support a REPORT LUN command
*/
ret = 1;
goto out_err;
}
/*
* 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, sdev_printk (KERN_INFO, sdev,
"scsi scan: REPORT LUN scan\n"));
/*
* 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 > 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.
*/
sdev_printk(KERN_ERR, sdev,
"Unexpected response"
" from lun %d while scanning, scan"
" aborted\n", lun);
break;
}
}
}
out_err:
kfree(lun_data);
out:
scsi_device_put(sdev);
if (scsi_device_created(sdev))
/*
* the sdev we used didn't appear in the report luns scan
*/
scsi_destroy_sdev(sdev);
return ret;
}
struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
uint id, uint lun, void *hostdata)
{
struct scsi_device *sdev = ERR_PTR(-ENODEV);
struct device *parent = &shost->shost_gendev;
struct scsi_target *starget;
if (strncmp(scsi_scan_type, "none", 4) == 0)
return ERR_PTR(-ENODEV);
starget = scsi_alloc_target(parent, channel, id);
if (!starget)
return ERR_PTR(-ENOMEM);
mutex_lock(&shost->scan_mutex);
if (!shost->async_scan)
scsi_complete_async_scans();
if (scsi_host_scan_allowed(shost))
scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
mutex_unlock(&shost->scan_mutex);
scsi_target_reap(starget);
put_device(&starget->dev);
return sdev;
}
EXPORT_SYMBOL(__scsi_add_device);
int scsi_add_device(struct Scsi_Host *host, uint channel,
uint target, uint lun)
{
struct scsi_device *sdev =
__scsi_add_device(host, channel, target, lun, NULL);
if (IS_ERR(sdev))
return PTR_ERR(sdev);
scsi_device_put(sdev);
return 0;
}
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);
static 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_target *starget;
if (shost->this_id == id)
/*
* Don't scan the host adapter
*/
return;
starget = scsi_alloc_target(parent, channel, id);
if (!starget)
return;
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, NULL, rescan, NULL);
if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
/*
* The REPORT LUN did not scan the target,
* do a sequential scan.
*/
scsi_sequential_lun_scan(starget, bflags,
starget->scsi_level, rescan);
}
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);
}
/**
* scsi_scan_target - scan a target id, possibly including all LUNs on the target.
* @parent: host to scan
* @channel: channel to scan
* @id: target id to scan
* @lun: Specific LUN to scan or SCAN_WILD_CARD
* @rescan: passed to LUN scanning routines
*
* Description:
* Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
* and possibly all LUNs on the target id.
*
* 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);
if (strncmp(scsi_scan_type, "none", 4) == 0)
return;
mutex_lock(&shost->scan_mutex);
if (!shost->async_scan)
scsi_complete_async_scans();
if (scsi_host_scan_allowed(shost))
__scsi_scan_target(parent, channel, id, lun, rescan);
mutex_unlock(&shost->scan_mutex);
}
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, shost_printk (KERN_INFO, shost,
"%s: <%u:%u:%u>\n",
__func__, 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;
mutex_lock(&shost->scan_mutex);
if (!shost->async_scan)
scsi_complete_async_scans();
if (scsi_host_scan_allowed(shost)) {
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);
}
mutex_unlock(&shost->scan_mutex);
return 0;
}
static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
{
struct scsi_device *sdev;
shost_for_each_device(sdev, shost) {
if (!scsi_host_scan_allowed(shost) ||
scsi_sysfs_add_sdev(sdev) != 0)
scsi_destroy_sdev(sdev);
}
}
/**
* scsi_prep_async_scan - prepare for an async scan
* @shost: the host which will be scanned
* Returns: a cookie to be passed to scsi_finish_async_scan()
*
* Tells the midlayer this host is going to do an asynchronous scan.
* It reserves the host's position in the scanning list and ensures
* that other asynchronous scans started after this one won't affect the
* ordering of the discovered devices.
*/
static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
{
struct async_scan_data *data;
unsigned long flags;
if (strncmp(scsi_scan_type, "sync", 4) == 0)
return NULL;
if (shost->async_scan) {
printk("%s called twice for host %d", __func__,
shost->host_no);
dump_stack();
return NULL;
}
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
goto err;
data->shost = scsi_host_get(shost);
if (!data->shost)
goto err;
init_completion(&data->prev_finished);
mutex_lock(&shost->scan_mutex);
spin_lock_irqsave(shost->host_lock, flags);
shost->async_scan = 1;
spin_unlock_irqrestore(shost->host_lock, flags);
mutex_unlock(&shost->scan_mutex);
spin_lock(&async_scan_lock);
if (list_empty(&scanning_hosts))
complete(&data->prev_finished);
list_add_tail(&data->list, &scanning_hosts);
spin_unlock(&async_scan_lock);
return data;
err:
kfree(data);
return NULL;
}
/**
* scsi_finish_async_scan - asynchronous scan has finished
* @data: cookie returned from earlier call to scsi_prep_async_scan()
*
* All the devices currently attached to this host have been found.
* This function announces all the devices it has found to the rest
* of the system.
*/
static void scsi_finish_async_scan(struct async_scan_data *data)
{
struct Scsi_Host *shost;
unsigned long flags;
if (!data)
return;
shost = data->shost;
mutex_lock(&shost->scan_mutex);
if (!shost->async_scan) {
printk("%s called twice for host %d", __func__,
shost->host_no);
dump_stack();
mutex_unlock(&shost->scan_mutex);
return;
}
wait_for_completion(&data->prev_finished);
scsi_sysfs_add_devices(shost);
spin_lock_irqsave(shost->host_lock, flags);
shost->async_scan = 0;
spin_unlock_irqrestore(shost->host_lock, flags);
mutex_unlock(&shost->scan_mutex);
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);
}
spin_unlock(&async_scan_lock);
scsi_host_put(shost);
kfree(data);
}
static void do_scsi_scan_host(struct Scsi_Host *shost)
{
if (shost->hostt->scan_finished) {
unsigned long start = jiffies;
if (shost->hostt->scan_start)
shost->hostt->scan_start(shost);
while (!shost->hostt->scan_finished(shost, jiffies - start))
msleep(10);
} else {
scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
SCAN_WILD_CARD, 0);
}
}
static int do_scan_async(void *_data)
{
struct async_scan_data *data = _data;
do_scsi_scan_host(data->shost);
scsi_finish_async_scan(data);
return 0;
}
/**
* scsi_scan_host - scan the given adapter
* @shost: adapter to scan
**/
void scsi_scan_host(struct Scsi_Host *shost)
{
struct task_struct *p;
struct async_scan_data *data;
if (strncmp(scsi_scan_type, "none", 4) == 0)
return;
data = scsi_prep_async_scan(shost);
if (!data) {
do_scsi_scan_host(shost);
return;
}
p = kthread_run(do_scan_async, data, "scsi_scan_%d", shost->host_no);
if (IS_ERR(p))
do_scan_async(data);
}
EXPORT_SYMBOL(scsi_scan_host);
void scsi_forget_host(struct Scsi_Host *shost)
{
struct scsi_device *sdev;
unsigned long flags;
restart:
spin_lock_irqsave(shost->host_lock, flags);
list_for_each_entry(sdev, &shost->__devices, siblings) {
if (sdev->sdev_state == SDEV_DEL)
continue;
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_device(sdev);
goto restart;
}
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 = NULL;
struct scsi_target *starget;
mutex_lock(&shost->scan_mutex);
if (!scsi_host_scan_allowed(shost))
goto out;
starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
if (!starget)
goto out;
sdev = scsi_alloc_sdev(starget, 0, NULL);
if (sdev) {
sdev->sdev_gendev.parent = get_device(&starget->dev);
sdev->borken = 0;
} else
scsi_target_reap(starget);
put_device(&starget->dev);
out:
mutex_unlock(&shost->scan_mutex);
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);
scsi_destroy_sdev(sdev);
}
EXPORT_SYMBOL(scsi_free_host_dev);