almalinux/kernel
14
0
Fork 0
Code Issues Pull Requests Releases Activity
a3bb58653c
kernel/drivers/scsi/scsi_scan.c

2046 lines
57 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
/*
* scsi_scan.c
*
* Copyright (C) 2000 Eric Youngdale,
* Copyright (C) 2002 Patrick Mansfield
*
* The general scanning/probing algorithm is as follows, exceptions are
* made to it depending on device specific flags, compilation options, and
* global variable (boot or module load time) settings.
*
* A specific LUN is scanned via an INQUIRY command; if the LUN has a
* device attached, a scsi_device is allocated and setup for it.
*
* For every id of every channel on the given host:
*
* Scan LUN 0; if the target responds to LUN 0 (even if there is no
* device or storage attached to LUN 0):
*
* If LUN 0 has a device attached, allocate and setup a
* scsi_device for it.
*
* If target is SCSI-3 or up, issue a REPORT LUN, and scan
* all of the LUNs returned by the REPORT LUN; else,
* sequentially scan LUNs up until some maximum is reached,
* or a LUN is seen that cannot have a device attached to it.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/spinlock.h>
#include <linux/async.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_devinfo.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_dh.h>
#include <scsi/scsi_eh.h>
#include "scsi_priv.h"
#include "scsi_logging.h"
#define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
" SCSI scanning, some SCSI devices might not be configured\n"
/*
* Default timeout
*/
#define SCSI_TIMEOUT (2*HZ)
#define SCSI_REPORT_LUNS_TIMEOUT (30*HZ)
/*
* Prefix values for the SCSI id's (stored in sysfs name field)
*/
#define SCSI_UID_SER_NUM 'S'
#define SCSI_UID_UNKNOWN 'Z'
/*
* Return values of some of the scanning functions.
*
* SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
* includes allocation or general failures preventing IO from being sent.
*
* SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
* on the given LUN.
*
* SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
* given LUN.
*/
#define SCSI_SCAN_NO_RESPONSE 0
#define SCSI_SCAN_TARGET_PRESENT 1
#define SCSI_SCAN_LUN_PRESENT 2
static const char *scsi_null_device_strs = "nullnullnullnull";
#define MAX_SCSI_LUNS 512
static u64 max_scsi_luns = MAX_SCSI_LUNS;
module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(max_luns,
"last scsi LUN (should be between 1 and 2^64-1)");
#ifdef CONFIG_SCSI_SCAN_ASYNC
#define SCSI_SCAN_TYPE_DEFAULT "async"
#else
#define SCSI_SCAN_TYPE_DEFAULT "sync"
#endif
static char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT;
module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type),
S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scan, "sync, async, manual, or none. "
"Setting to 'manual' disables automatic scanning, but allows "
"for manual device scan via the 'scan' sysfs attribute.");
static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(inq_timeout,
"Timeout (in seconds) waiting for devices to answer INQUIRY."
" Default is 20. Some devices may need more; most need less.");
/* This lock protects only this list */
static DEFINE_SPINLOCK(async_scan_lock);
static LIST_HEAD(scanning_hosts);
struct async_scan_data {
struct list_head list;
struct Scsi_Host *shost;
struct completion prev_finished;
};
/*
* scsi_enable_async_suspend - Enable async suspend and resume
*/
void scsi_enable_async_suspend(struct device *dev)
{
/*
* If a user has disabled async probing a likely reason is due to a
* storage enclosure that does not inject staggered spin-ups. For
* safety, make resume synchronous as well in that case.
*/
if (strncmp(scsi_scan_type, "async", 5) != 0)
return;
/* Enable asynchronous suspend and resume. */
device_enable_async_suspend(dev);
}
/**
* scsi_complete_async_scans - Wait for asynchronous scans to complete
*
* When this function returns, any host which started scanning before
* this function was called will have finished its scan. Hosts which
* started scanning after this function was called may or may not have
* finished.
*/
int scsi_complete_async_scans(void)
{
struct async_scan_data *data;
do {
if (list_empty(&scanning_hosts))
return 0;
/* If we can't get memory immediately, that's OK. Just
* sleep a little. Even if we never get memory, the async
* scans will finish eventually.
*/
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
msleep(1);
} while (!data);
data->shost = NULL;
init_completion(&data->prev_finished);
spin_lock(&async_scan_lock);
/* Check that there's still somebody else on the list */
if (list_empty(&scanning_hosts))
goto done;
list_add_tail(&data->list, &scanning_hosts);
spin_unlock(&async_scan_lock);
printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
wait_for_completion(&data->prev_finished);
spin_lock(&async_scan_lock);
list_del(&data->list);
if (!list_empty(&scanning_hosts)) {
struct async_scan_data *next = list_entry(scanning_hosts.next,
struct async_scan_data, list);
complete(&next->prev_finished);
}
done:
spin_unlock(&async_scan_lock);
kfree(data);
return 0;
}
/**
* scsi_unlock_floptical - unlock device via a special MODE SENSE command
* @sdev: scsi device to send command to
* @result: area to store the result of the MODE SENSE
*
* Description:
* Send a vendor specific MODE SENSE (not a MODE SELECT) command.
* Called for BLIST_KEY devices.
**/
static void scsi_unlock_floptical(struct scsi_device *sdev,
unsigned char *result)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
scsi_cmd[0] = MODE_SENSE;
scsi_cmd[1] = 0;
scsi_cmd[2] = 0x2e;
scsi_cmd[3] = 0;
scsi_cmd[4] = 0x2a; /* size */
scsi_cmd[5] = 0;
scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, result, 0x2a,
SCSI_TIMEOUT, 3, NULL);
}
static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev,
unsigned int depth)
{
int new_shift = sbitmap_calculate_shift(depth);
bool need_alloc = !sdev->budget_map.map;
bool need_free = false;
int ret;
struct sbitmap sb_backup;
depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev));
/*
* realloc if new shift is calculated, which is caused by setting
* up one new default queue depth after calling ->device_configure
*/
if (!need_alloc && new_shift != sdev->budget_map.shift)
need_alloc = need_free = true;
if (!need_alloc)
return 0;
/*
* Request queue has to be frozen for reallocating budget map,
* and here disk isn't added yet, so freezing is pretty fast
*/
if (need_free) {
blk_mq_freeze_queue(sdev->request_queue);
sb_backup = sdev->budget_map;
}
ret = sbitmap_init_node(&sdev->budget_map,
scsi_device_max_queue_depth(sdev),
new_shift, GFP_KERNEL,
sdev->request_queue->node, false, true);
if (!ret)
sbitmap_resize(&sdev->budget_map, depth);
if (need_free) {
if (ret)
sdev->budget_map = sb_backup;
else
sbitmap_free(&sb_backup);
ret = 0;
blk_mq_unfreeze_queue(sdev->request_queue);
}
return ret;
}
/**
* scsi_alloc_sdev - allocate and setup a scsi_Device
* @starget: which target to allocate a &scsi_device for
* @lun: which lun
* @hostdata: usually NULL and set by ->slave_alloc instead
*
* Description:
* Allocate, initialize for io, and return a pointer to a scsi_Device.
* Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
* adds scsi_Device to the appropriate list.
*
* Return value:
* scsi_Device pointer, or NULL on failure.
**/
static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
u64 lun, void *hostdata)
{
unsigned int depth;
struct scsi_device *sdev;
struct request_queue *q;
int display_failure_msg = 1, ret;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct queue_limits lim;
sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
GFP_KERNEL);
if (!sdev)
goto out;
sdev->vendor = scsi_null_device_strs;
sdev->model = scsi_null_device_strs;
sdev->rev = scsi_null_device_strs;
sdev->host = shost;
sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
sdev->id = starget->id;
sdev->lun = lun;
sdev->channel = starget->channel;
mutex_init(&sdev->state_mutex);
sdev->sdev_state = SDEV_CREATED;
INIT_LIST_HEAD(&sdev->siblings);
INIT_LIST_HEAD(&sdev->same_target_siblings);
INIT_LIST_HEAD(&sdev->starved_entry);
INIT_LIST_HEAD(&sdev->event_list);
spin_lock_init(&sdev->list_lock);
mutex_init(&sdev->inquiry_mutex);
INIT_WORK(&sdev->event_work, scsi_evt_thread);
INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
sdev->sdev_gendev.parent = get_device(&starget->dev);
sdev->sdev_target = starget;
/* usually NULL and set by ->slave_alloc instead */
sdev->hostdata = hostdata;
/* if the device needs this changing, it may do so in the
* slave_configure function */
sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
/*
* Some low level driver could use device->type
*/
sdev->type = -1;
/*
* Assume that the device will have handshaking problems,
* and then fix this field later if it turns out it
* doesn't
*/
sdev->borken = 1;
sdev->sg_reserved_size = INT_MAX;
scsi_init_limits(shost, &lim);
q = blk_mq_alloc_queue(&sdev->host->tag_set, &lim, sdev);
if (IS_ERR(q)) {
/* release fn is set up in scsi_sysfs_device_initialise, so
* have to free and put manually here */
put_device(&starget->dev);
kfree(sdev);
goto out;
}
kref_get(&sdev->host->aux->tagset_refcnt);
sdev->request_queue = q;
depth = sdev->host->cmd_per_lun ?: 1;
/*
* Use .can_queue as budget map's depth because we have to
* support adjusting queue depth from sysfs. Meantime use
* default device queue depth to figure out sbitmap shift
* since we use this queue depth most of times.
*/
if (scsi_realloc_sdev_budget_map(sdev, depth)) {
put_device(&starget->dev);
kfree(sdev);
goto out;
}
scsi_change_queue_depth(sdev, depth);
scsi_sysfs_device_initialize(sdev);
if (shost->hostt->slave_alloc) {
ret = shost->hostt->slave_alloc(sdev);
if (ret) {
/*
* if LLDD reports slave not present, don't clutter
* console with alloc failure messages
*/
if (ret == -ENXIO)
display_failure_msg = 0;
goto out_device_destroy;
}
}
return sdev;
out_device_destroy:
__scsi_remove_device(sdev);
out:
if (display_failure_msg)
printk(ALLOC_FAILURE_MSG, __func__);
return NULL;
}
static void scsi_target_destroy(struct scsi_target *starget)
{
struct device *dev = &starget->dev;
struct Scsi_Host *shost = dev_to_shost(dev->parent);
unsigned long flags;
BUG_ON(starget->state == STARGET_DEL);
starget->state = STARGET_DEL;
transport_destroy_device(dev);
spin_lock_irqsave(shost->host_lock, flags);
if (shost->hostt->target_destroy)
shost->hostt->target_destroy(starget);
list_del_init(&starget->siblings);
spin_unlock_irqrestore(shost->host_lock, flags);
put_device(dev);
}
static void scsi_target_dev_release(struct device *dev)
{
struct device *parent = dev->parent;
struct scsi_target *starget = to_scsi_target(dev);
kfree(starget);
put_device(parent);
}
static const struct device_type scsi_target_type = {
.name = "scsi_target",
.release = scsi_target_dev_release,
};
int scsi_is_target_device(const struct device *dev)
{
return dev->type == &scsi_target_type;
}
EXPORT_SYMBOL(scsi_is_target_device);
static struct scsi_target *__scsi_find_target(struct device *parent,
int channel, uint id)
{
struct scsi_target *starget, *found_starget = NULL;
struct Scsi_Host *shost = dev_to_shost(parent);
/*
* Search for an existing target for this sdev.
*/
list_for_each_entry(starget, &shost->__targets, siblings) {
if (starget->id == id &&
starget->channel == channel) {
found_starget = starget;
break;
}
}
if (found_starget)
get_device(&found_starget->dev);
return found_starget;
}
/**
* scsi_target_reap_ref_release - remove target from visibility
* @kref: the reap_ref in the target being released
*
* Called on last put of reap_ref, which is the indication that no device
* under this target is visible anymore, so render the target invisible in
* sysfs. Note: we have to be in user context here because the target reaps
* should be done in places where the scsi device visibility is being removed.
*/
static void scsi_target_reap_ref_release(struct kref *kref)
{
struct scsi_target *starget
= container_of(kref, struct scsi_target, reap_ref);
/*
* if we get here and the target is still in a CREATED state that
* means it was allocated but never made visible (because a scan
* turned up no LUNs), so don't call device_del() on it.
*/
if ((starget->state != STARGET_CREATED) &&
(starget->state != STARGET_CREATED_REMOVE)) {
transport_remove_device(&starget->dev);
device_del(&starget->dev);
}
scsi_target_destroy(starget);
}
static void scsi_target_reap_ref_put(struct scsi_target *starget)
{
kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
}
/**
* scsi_alloc_target - allocate a new or find an existing target
* @parent: parent of the target (need not be a scsi host)
* @channel: target channel number (zero if no channels)
* @id: target id number
*
* Return an existing target if one exists, provided it hasn't already
* gone into STARGET_DEL state, otherwise allocate a new target.
*
* The target is returned with an incremented reference, so the caller
* is responsible for both reaping and doing a last put
*/
static struct scsi_target *scsi_alloc_target(struct device *parent,
int channel, uint id)
{
struct Scsi_Host *shost = dev_to_shost(parent);
struct device *dev = NULL;
unsigned long flags;
const int size = sizeof(struct scsi_target)
+ shost->transportt->target_size;
struct scsi_target *starget;
struct scsi_target *found_target;
int error, ref_got;
starget = kzalloc(size, GFP_KERNEL);
if (!starget) {
printk(KERN_ERR "%s: allocation failure\n", __func__);
return NULL;
}
dev = &starget->dev;
device_initialize(dev);
kref_init(&starget->reap_ref);
dev->parent = get_device(parent);
dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
dev->bus = &scsi_bus_type;
dev->type = &scsi_target_type;
scsi_enable_async_suspend(dev);
starget->id = id;
starget->channel = channel;
starget->can_queue = 0;
INIT_LIST_HEAD(&starget->siblings);
INIT_LIST_HEAD(&starget->devices);
starget->state = STARGET_CREATED;
starget->scsi_level = SCSI_2;
starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
retry:
spin_lock_irqsave(shost->host_lock, flags);
found_target = __scsi_find_target(parent, channel, id);
if (found_target)
goto found;
list_add_tail(&starget->siblings, &shost->__targets);
spin_unlock_irqrestore(shost->host_lock, flags);
/* allocate and add */
transport_setup_device(dev);
if (shost->hostt->target_alloc) {
error = shost->hostt->target_alloc(starget);
if(error) {
if (error != -ENXIO)
dev_err(dev, "target allocation failed, error %d\n", error);
/* don't want scsi_target_reap to do the final
* put because it will be under the host lock */
scsi_target_destroy(starget);
return NULL;
}
}
get_device(dev);
return starget;
found:
/*
* release routine already fired if kref is zero, so if we can still
* take the reference, the target must be alive. If we can't, it must
* be dying and we need to wait for a new target
*/
ref_got = kref_get_unless_zero(&found_target->reap_ref);
spin_unlock_irqrestore(shost->host_lock, flags);
if (ref_got) {
put_device(dev);
return found_target;
}
/*
* Unfortunately, we found a dying target; need to wait until it's
* dead before we can get a new one. There is an anomaly here. We
* *should* call scsi_target_reap() to balance the kref_get() of the
* reap_ref above. However, since the target being released, it's
* already invisible and the reap_ref is irrelevant. If we call
* scsi_target_reap() we might spuriously do another device_del() on
* an already invisible target.
*/
put_device(&found_target->dev);
/*
* length of time is irrelevant here, we just want to yield the CPU
* for a tick to avoid busy waiting for the target to die.
*/
msleep(1);
goto retry;
}
/**
* scsi_target_reap - check to see if target is in use and destroy if not
* @starget: target to be checked
*
* This is used after removing a LUN or doing a last put of the target
* it checks atomically that nothing is using the target and removes
* it if so.
*/
void scsi_target_reap(struct scsi_target *starget)
{
/*
* serious problem if this triggers: STARGET_DEL is only set in the if
* the reap_ref drops to zero, so we're trying to do another final put
* on an already released kref
*/
BUG_ON(starget->state == STARGET_DEL);
scsi_target_reap_ref_put(starget);
}
/**
* scsi_sanitize_inquiry_string - remove non-graphical chars from an
* INQUIRY result string
* @s: INQUIRY result string to sanitize
* @len: length of the string
*
* Description:
* The SCSI spec says that INQUIRY vendor, product, and revision
* strings must consist entirely of graphic ASCII characters,
* padded on the right with spaces. Since not all devices obey
* this rule, we will replace non-graphic or non-ASCII characters
* with spaces. Exception: a NUL character is interpreted as a
* string terminator, so all the following characters are set to
* spaces.
**/
void scsi_sanitize_inquiry_string(unsigned char *s, int len)
{
int terminated = 0;
for (; len > 0; (--len, ++s)) {
if (*s == 0)
terminated = 1;
if (terminated || *s < 0x20 || *s > 0x7e)
*s = ' ';
}
}
EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
/**
* scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
* @sdev: scsi_device to probe
* @inq_result: area to store the INQUIRY result
* @result_len: len of inq_result
* @bflags: store any bflags found here
*
* Description:
* Probe the lun associated with @req using a standard SCSI INQUIRY;
*
* If the INQUIRY is successful, zero is returned and the
* INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
* are copied to the scsi_device any flags value is stored in *@bflags.
**/
static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
int result_len, blist_flags_t *bflags)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
int first_inquiry_len, try_inquiry_len, next_inquiry_len;
int response_len = 0;
int pass, count, result, resid;
struct scsi_failure failure_defs[] = {
/*
* 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.
*/
{
.sense = UNIT_ATTENTION,
.asc = 0x28,
.result = SAM_STAT_CHECK_CONDITION,
},
{
.sense = UNIT_ATTENTION,
.asc = 0x29,
.result = SAM_STAT_CHECK_CONDITION,
},
{
.allowed = 1,
.result = DID_TIME_OUT << 16,
},
{}
};
struct scsi_failures failures = {
.total_allowed = 3,
.failure_definitions = failure_defs,
};
const struct scsi_exec_args exec_args = {
.resid = &resid,
.failures = &failures,
};
*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 */
scsi_failures_reset_retries(&failures);
for (count = 0; count < 3; ++count) {
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_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,
inq_result, try_inquiry_len,
HZ / 2 + HZ * scsi_inq_timeout, 3,
&exec_args);
SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
"scsi scan: INQUIRY %s with code 0x%x\n",
result ? "failed" : "successful", result));
if (result == 0) {
/*
* if nothing was transferred, we try
* again. It's a workaround for some USB
* devices.
*/
if (resid == try_inquiry_len)
continue;
}
break;
}
if (result == 0) {
scsi_sanitize_inquiry_string(&inq_result[8], 8);
scsi_sanitize_inquiry_string(&inq_result[16], 16);
scsi_sanitize_inquiry_string(&inq_result[32], 4);
response_len = inq_result[4] + 5;
if (response_len > 255)
response_len = first_inquiry_len; /* sanity */
/*
* Get any flags for this device.
*
* XXX add a bflags to scsi_device, and replace the
* corresponding bit fields in scsi_device, so bflags
* need not be passed as an argument.
*/
*bflags = scsi_get_device_flags(sdev, &inq_result[8],
&inq_result[16]);
/* When the first pass succeeds we gain information about
* what larger transfer lengths might work. */
if (pass == 1) {
if (BLIST_INQUIRY_36 & *bflags)
next_inquiry_len = 36;
/*
* LLD specified a maximum sdev->inquiry_len
* but device claims it has more data. Capping
* the length only makes sense for legacy
* devices. If a device supports SPC-4 (2014)
* or newer, assume that it is safe to ask for
* as much as the device says it supports.
*/
else if (sdev->inquiry_len &&
response_len > sdev->inquiry_len &&
(inq_result[2] & 0x7) < 6) /* SPC-4 */
next_inquiry_len = sdev->inquiry_len;
else
next_inquiry_len = response_len;
/* If more data is available perform the second pass */
if (next_inquiry_len > try_inquiry_len) {
try_inquiry_len = next_inquiry_len;
pass = 2;
goto next_pass;
}
}
} else if (pass == 2) {
sdev_printk(KERN_INFO, sdev,
"scsi scan: %d byte inquiry failed. "
"Consider BLIST_INQUIRY_36 for this device\n",
try_inquiry_len);
/* If this pass failed, the third pass goes back and transfers
* the same amount as we successfully got in the first pass. */
try_inquiry_len = first_inquiry_len;
pass = 3;
goto next_pass;
}
/* If the last transfer attempt got an error, assume the
* peripheral doesn't exist or is dead. */
if (result)
return -EIO;
/* Don't report any more data than the device says is valid */
sdev->inquiry_len = min(try_inquiry_len, response_len);
/*
* XXX Abort if the response length is less than 36? If less than
* 32, the lookup of the device flags (above) could be invalid,
* and it would be possible to take an incorrect action - we do
* not want to hang because of a short INQUIRY. On the flip side,
* if the device is spun down or becoming ready (and so it gives a
* short INQUIRY), an abort here prevents any further use of the
* device, including spin up.
*
* On the whole, the best approach seems to be to assume the first
* 36 bytes are valid no matter what the device says. That's
* better than copying < 36 bytes to the inquiry-result buffer
* and displaying garbage for the Vendor, Product, or Revision
* strings.
*/
if (sdev->inquiry_len < 36) {
if (!sdev->host->short_inquiry) {
shost_printk(KERN_INFO, sdev->host,
"scsi scan: INQUIRY result too short (%d),"
" using 36\n", sdev->inquiry_len);
sdev->host->short_inquiry = 1;
}
sdev->inquiry_len = 36;
}
/*
* Related to the above issue:
*
* XXX Devices (disk or all?) should be sent a TEST UNIT READY,
* and if not ready, sent a START_STOP to start (maybe spin up) and
* then send the INQUIRY again, since the INQUIRY can change after
* a device is initialized.
*
* Ideally, start a device if explicitly asked to do so. This
* assumes that a device is spun up on power on, spun down on
* request, and then spun up on request.
*/
/*
* The scanning code needs to know the scsi_level, even if no
* device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
* non-zero LUNs can be scanned.
*/
sdev->scsi_level = inq_result[2] & 0x0f;
if (sdev->scsi_level >= 2 ||
(sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
sdev->scsi_level++;
sdev->sdev_target->scsi_level = sdev->scsi_level;
/*
* If SCSI-2 or lower, and if the transport requires it,
* store the LUN value in CDB[1].
*/
sdev->lun_in_cdb = 0;
if (sdev->scsi_level <= SCSI_2 &&
sdev->scsi_level != SCSI_UNKNOWN &&
!sdev->host->no_scsi2_lun_in_cdb)
sdev->lun_in_cdb = 1;
return 0;
}
/**
* scsi_add_lun - allocate and fully initialze a scsi_device
* @sdev: holds information to be stored in the new scsi_device
* @inq_result: holds the result of a previous INQUIRY to the LUN
* @bflags: black/white list flag
* @async: 1 if this device is being scanned asynchronously
*
* Description:
* Initialize the scsi_device @sdev. Optionally set fields based
* on values in *@bflags.
*
* Return:
* SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
* SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
**/
static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
blist_flags_t *bflags, int async)
{
const struct scsi_host_template *hostt = sdev->host->hostt;
struct queue_limits lim;
int ret;
/*
* XXX do not save the inquiry, since it can change underneath us,
* save just vendor/model/rev.
*
* Rather than save it and have an ioctl that retrieves the saved
* value, have an ioctl that executes the same INQUIRY code used
* in scsi_probe_lun, let user level programs doing INQUIRY
* scanning run at their own risk, or supply a user level program
* that can correctly scan.
*/
/*
* Copy at least 36 bytes of INQUIRY data, so that we don't
* dereference unallocated memory when accessing the Vendor,
* Product, and Revision strings. Badly behaved devices may set
* the INQUIRY Additional Length byte to a small value, indicating
* these strings are invalid, but often they contain plausible data
* nonetheless. It doesn't matter if the device sent < 36 bytes
* total, since scsi_probe_lun() initializes inq_result with 0s.
*/
sdev->inquiry = kmemdup(inq_result,
max_t(size_t, sdev->inquiry_len, 36),
GFP_KERNEL);
if (sdev->inquiry == NULL)
return SCSI_SCAN_NO_RESPONSE;
sdev->vendor = (char *) (sdev->inquiry + 8);
sdev->model = (char *) (sdev->inquiry + 16);
sdev->rev = (char *) (sdev->inquiry + 32);
if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
/*
* sata emulation layer device. This is a hack to work around
* the SATL power management specifications which state that
* when the SATL detects the device has gone into standby
* mode, it shall respond with NOT READY.
*/
sdev->allow_restart = 1;
}
if (*bflags & BLIST_ISROM) {
sdev->type = TYPE_ROM;
sdev->removable = 1;
} else {
sdev->type = (inq_result[0] & 0x1f);
sdev->removable = (inq_result[1] & 0x80) >> 7;
/*
* some devices may respond with wrong type for
* well-known logical units. Force well-known type
* to enumerate them correctly.
*/
if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
sdev_printk(KERN_WARNING, sdev,
"%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
__func__, sdev->type, (unsigned int)sdev->lun);
sdev->type = TYPE_WLUN;
}
}
if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
/* RBC and MMC devices can return SCSI-3 compliance and yet
* still not support REPORT LUNS, so make them act as
* BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
* specifically set */
if ((*bflags & BLIST_REPORTLUN2) == 0)
*bflags |= BLIST_NOREPORTLUN;
}
/*
* For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
* spec says: The device server is capable of supporting the
* specified peripheral device type on this logical unit. However,
* the physical device is not currently connected to this logical
* unit.
*
* The above is vague, as it implies that we could treat 001 and
* 011 the same. Stay compatible with previous code, and create a
* scsi_device for a PQ of 1
*
* Don't set the device offline here; rather let the upper
* level drivers eval the PQ to decide whether they should
* attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
*/
sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
sdev->lockable = sdev->removable;
sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
if (sdev->scsi_level >= SCSI_3 ||
(sdev->inquiry_len > 56 && inq_result[56] & 0x04))
sdev->ppr = 1;
if (inq_result[7] & 0x60)
sdev->wdtr = 1;
if (inq_result[7] & 0x10)
sdev->sdtr = 1;
sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
"ANSI: %d%s\n", scsi_device_type(sdev->type),
sdev->vendor, sdev->model, sdev->rev,
sdev->inq_periph_qual, inq_result[2] & 0x07,
(inq_result[3] & 0x0f) == 1 ? " CCS" : "");
if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
!(*bflags & BLIST_NOTQ)) {
sdev->tagged_supported = 1;
sdev->simple_tags = 1;
}
/*
* Some devices (Texel CD ROM drives) have handshaking problems
* when used with the Seagate controllers. borken is initialized
* to 1, and then set it to 0 here.
*/
if ((*bflags & BLIST_BORKEN) == 0)
sdev->borken = 0;
if (*bflags & BLIST_NO_ULD_ATTACH)
sdev->no_uld_attach = 1;
/*
* Apparently some really broken devices (contrary to the SCSI
* standards) need to be selected without asserting ATN
*/
if (*bflags & BLIST_SELECT_NO_ATN)
sdev->select_no_atn = 1;
/*
* Some devices may not want to have a start command automatically
* issued when a device is added.
*/
if (*bflags & BLIST_NOSTARTONADD)
sdev->no_start_on_add = 1;
if (*bflags & BLIST_SINGLELUN)
scsi_target(sdev)->single_lun = 1;
sdev->use_10_for_rw = 1;
/* some devices don't like REPORT SUPPORTED OPERATION CODES
* and will simply timeout causing sd_mod init to take a very
* very long time */
if (*bflags & BLIST_NO_RSOC)
sdev->no_report_opcodes = 1;
/* set the device running here so that slave configure
* may do I/O */
mutex_lock(&sdev->state_mutex);
ret = scsi_device_set_state(sdev, SDEV_RUNNING);
if (ret)
ret = scsi_device_set_state(sdev, SDEV_BLOCK);
mutex_unlock(&sdev->state_mutex);
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_NOT_LOCKABLE)
sdev->lockable = 0;
if (*bflags & BLIST_RETRY_HWERROR)
sdev->retry_hwerror = 1;
if (*bflags & BLIST_NO_DIF)
sdev->no_dif = 1;
if (*bflags & BLIST_UNMAP_LIMIT_WS)
sdev->unmap_limit_for_ws = 1;
if (*bflags & BLIST_IGN_MEDIA_CHANGE)
sdev->ignore_media_change = 1;
sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
if (*bflags & BLIST_TRY_VPD_PAGES)
sdev->try_vpd_pages = 1;
else if (*bflags & BLIST_SKIP_VPD_PAGES)
sdev->skip_vpd_pages = 1;
if (*bflags & BLIST_NO_VPD_SIZE)
sdev->no_vpd_size = 1;
transport_configure_device(&sdev->sdev_gendev);
/*
* No need to freeze the queue as it isn't reachable to anyone else yet.
*/
lim = queue_limits_start_update(sdev->request_queue);
if (*bflags & BLIST_MAX_512)
lim.max_hw_sectors = 512;
else if (*bflags & BLIST_MAX_1024)
lim.max_hw_sectors = 1024;
if (hostt->device_configure)
ret = hostt->device_configure(sdev, &lim);
else if (hostt->slave_configure)
ret = hostt->slave_configure(sdev);
if (ret) {
queue_limits_cancel_update(sdev->request_queue);
/*
* If the LLDD reports device not present, don't clutter the
* console with failure messages.
*/
if (ret != -ENXIO)
sdev_printk(KERN_ERR, sdev,
"failed to configure device\n");
return SCSI_SCAN_NO_RESPONSE;
}
ret = queue_limits_commit_update(sdev->request_queue, &lim);
if (ret) {
sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n");
return SCSI_SCAN_NO_RESPONSE;
}
/*
* The queue_depth is often changed in ->device_configure.
*
* Set up budget map again since memory consumption of the map depends
* on actual queue depth.
*/
if (hostt->device_configure || hostt->slave_configure)
scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth);
if (sdev->scsi_level >= SCSI_3)
scsi_attach_vpd(sdev);
scsi_cdl_check(sdev);
sdev->max_queue_depth = sdev->queue_depth;
WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth);
sdev->sdev_bflags = *bflags;
/*
* 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;
}
#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 not equal to SCSI_SCAN_INITIAL 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,
u64 lun, blist_flags_t *bflagsp,
struct scsi_device **sdevp,
enum scsi_scan_mode rescan,
void *hostdata)
{
struct scsi_device *sdev;
unsigned char *result;
blist_flags_t bflags;
int 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_SCAN_INITIAL || !scsi_device_created(sdev)) {
SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
"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_KERNEL);
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) {
/*
* 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, sdev_printk(KERN_INFO, sdev,
"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_remove_device(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,
blist_flags_t bflags, int scsi_level,
enum scsi_scan_mode rescan)
{
uint max_dev_lun;
u64 sparse_lun, lun;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
"scsi scan: Sequential scan\n"));
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_CCS, and no special lun scanning, stop
* scanning; this matches 2.4 behaviour, but could just be a bug
* (to continue scanning a SCSI_1_CCS 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);
else
max_dev_lun = min(256U, 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;
}
/**
* 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.
* If starget->no_report_luns is set, return 1 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, blist_flags_t bflags,
enum scsi_scan_mode rescan)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
unsigned int length;
u64 lun;
unsigned int num_luns;
int result;
struct scsi_lun *lunp, *lun_data;
struct scsi_device *sdev;
struct Scsi_Host *shost = dev_to_shost(&starget->dev);
struct scsi_failure failure_defs[] = {
{
.sense = UNIT_ATTENTION,
.asc = SCMD_FAILURE_ASC_ANY,
.ascq = SCMD_FAILURE_ASCQ_ANY,
.result = SAM_STAT_CHECK_CONDITION,
},
/* Fail all CCs except the UA above */
{
.sense = SCMD_FAILURE_SENSE_ANY,
.result = SAM_STAT_CHECK_CONDITION,
},
/* Retry any other errors not listed above */
{
.result = SCMD_FAILURE_RESULT_ANY,
},
{}
};
struct scsi_failures failures = {
.total_allowed = 3,
.failure_definitions = failure_defs,
};
const struct scsi_exec_args exec_args = {
.failures = &failures,
};
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.
* Don't attempt if the target doesn't support REPORT 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 (starget->no_report_luns)
return 1;
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)) {
__scsi_remove_device(sdev);
return 0;
}
}
/*
* Allocate enough to hold the header (the same size as one scsi_lun)
* plus the number of luns we are requesting. 511 was the default
* value of the now removed max_report_luns parameter.
*/
length = (511 + 1) * sizeof(struct scsi_lun);
retry:
lun_data = kmalloc(length, GFP_KERNEL);
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.
*/
put_unaligned_be32(length, &scsi_cmd[6]);
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.
*/
scsi_failures_reset_retries(&failures);
SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
"scsi scan: Sending REPORT LUNS\n"));
result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data,
length, SCSI_REPORT_LUNS_TIMEOUT, 3,
&exec_args);
SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
"scsi scan: REPORT LUNS %s result 0x%x\n",
result ? "failed" : "successful", result));
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.
*/
if (get_unaligned_be32(lun_data->scsi_lun) +
sizeof(struct scsi_lun) > length) {
length = get_unaligned_be32(lun_data->scsi_lun) +
sizeof(struct scsi_lun);
kfree(lun_data);
goto retry;
}
length = get_unaligned_be32(lun_data->scsi_lun);
num_luns = (length / sizeof(struct scsi_lun));
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);
if (lun > sdev->host->max_lun) {
sdev_printk(KERN_WARNING, sdev,
"lun%llu has a LUN larger than"
" allowed by the host adapter\n", 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 %llu while scanning, scan"
" aborted\n", (unsigned long long)lun);
break;
}
}
}
out_err:
kfree(lun_data);
out:
if (scsi_device_created(sdev))
/*
* the sdev we used didn't appear in the report luns scan
*/
__scsi_remove_device(sdev);
scsi_device_put(sdev);
return ret;
}
struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
uint id, u64 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);
scsi_autopm_get_target(starget);
mutex_lock(&shost->scan_mutex);
if (!shost->async_scan)
scsi_complete_async_scans();
if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
scsi_probe_and_add_lun(starget, lun, NULL, &sdev,
SCSI_SCAN_RESCAN, hostdata);
scsi_autopm_put_host(shost);
}
mutex_unlock(&shost->scan_mutex);
scsi_autopm_put_target(starget);
/*
* paired with scsi_alloc_target(). Target will be destroyed unless
* scsi_probe_and_add_lun made an underlying device visible
*/
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, u64 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);
int scsi_rescan_device_rh(struct device *dev)
{
struct scsi_device *sdev = to_scsi_device(dev);
int ret = 0;
device_lock(dev);
/*
* Bail out if the device or its queue are not running. Otherwise,
* the rescan may block waiting for commands to be executed, with us
* holding the device lock. This can result in a potential deadlock
* in the power management core code when system resume is on-going.
*/
if (sdev->sdev_state != SDEV_RUNNING ||
blk_queue_pm_only(sdev->request_queue)) {
ret = -EWOULDBLOCK;
goto unlock;
}
scsi_attach_vpd(sdev);
scsi_cdl_check(sdev);
if (sdev->handler && sdev->handler->rescan)
sdev->handler->rescan(sdev);
if (dev->driver && try_module_get(dev->driver->owner)) {
struct scsi_driver *drv = to_scsi_driver(dev->driver);
if (drv->rescan)
drv->rescan(dev);
module_put(dev->driver->owner);
}
unlock:
device_unlock(dev);
return ret;
}
EXPORT_SYMBOL(scsi_rescan_device_rh);
void scsi_rescan_device(struct device *dev)
{
scsi_rescan_device_rh(dev);
}
EXPORT_SYMBOL(scsi_rescan_device);
static void __scsi_scan_target(struct device *parent, unsigned int channel,
unsigned int id, u64 lun, enum scsi_scan_mode rescan)
{
struct Scsi_Host *shost = dev_to_shost(parent);
blist_flags_t 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;
scsi_autopm_get_target(starget);
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:
scsi_autopm_put_target(starget);
/*
* paired with scsi_alloc_target(): 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; SCSI_SCAN_INITIAL for
* no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
* and SCSI_SCAN_MANUAL to force scanning even if
* 'scan=manual' is set.
*
* 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, u64 lun, enum scsi_scan_mode rescan)
{
struct Scsi_Host *shost = dev_to_shost(parent);
if (strncmp(scsi_scan_type, "none", 4) == 0)
return;
if (rescan != SCSI_SCAN_MANUAL &&
strncmp(scsi_scan_type, "manual", 6) == 0)
return;
mutex_lock(&shost->scan_mutex);
if (!shost->async_scan)
scsi_complete_async_scans();
if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
__scsi_scan_target(parent, channel, id, lun, rescan);
scsi_autopm_put_host(shost);
}
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, u64 lun,
enum scsi_scan_mode 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, u64 lun,
enum scsi_scan_mode rescan)
{
SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
"%s: <%u:%u:%llu>\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) && scsi_autopm_get_host(shost) == 0) {
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);
scsi_autopm_put_host(shost);
}
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) {
/* target removed before the device could be added */
if (sdev->sdev_state == SDEV_DEL)
continue;
/* If device is already visible, skip adding it to sysfs */
if (sdev->is_visible)
continue;
if (!scsi_host_scan_allowed(shost) ||
scsi_sysfs_add_sdev(sdev) != 0)
__scsi_remove_device(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 = NULL;
unsigned long flags;
if (strncmp(scsi_scan_type, "sync", 4) == 0)
return NULL;
mutex_lock(&shost->scan_mutex);
if (shost->async_scan) {
shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
goto err;
}
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);
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:
mutex_unlock(&shost->scan_mutex);
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) {
shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
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_autopm_put_host(shost);
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, SCSI_SCAN_INITIAL);
}
}
static void do_scan_async(void *_data, async_cookie_t c)
{
struct async_scan_data *data = _data;
struct Scsi_Host *shost = data->shost;
do_scsi_scan_host(shost);
scsi_finish_async_scan(data);
}
/**
* scsi_scan_host - scan the given adapter
* @shost: adapter to scan
**/
void scsi_scan_host(struct Scsi_Host *shost)
{
struct async_scan_data *data;
if (strncmp(scsi_scan_type, "none", 4) == 0 ||
strncmp(scsi_scan_type, "manual", 6) == 0)
return;
if (scsi_autopm_get_host(shost) < 0)
return;
data = scsi_prep_async_scan(shost);
if (!data) {
do_scsi_scan_host(shost);
scsi_autopm_put_host(shost);
return;
}
/* register with the async subsystem so wait_for_device_probe()
* will flush this work
*/
async_schedule(do_scan_async, data);
/* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
}
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);
}
Reference in New Issue View Git Blame Copy Permalink