// 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.
*/
/* * 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
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);
/* * 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 {
scoped_guard(spinlock, &async_scan_lock) 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);
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);
/** * 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.
**/ staticvoid scsi_unlock_floptical(struct scsi_device *sdev, unsignedchar *result)
{ unsignedchar scsi_cmd[MAX_COMMAND_SIZE];
/* * realloc if new shift is calculated, which is caused by setting * up one new default queue depth after calling ->sdev_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) {
memflags = 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_NOIO,
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, memflags);
} 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 ->sdev_init 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.
**/ staticstruct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
u64 lun, void *hostdata)
{ unsignedint 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;
/* usually NULL and set by ->sdev_init instead */
sdev->hostdata = hostdata;
/* if the device needs this changing, it may do so in the
* sdev_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->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->sdev_init) {
ret = shost->hostt->sdev_init(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;
}
staticstruct 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.
*/ staticvoid 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);
}
/** * 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
*/ staticstruct scsi_target *scsi_alloc_target(struct device *parent, int channel, uint id)
{ struct Scsi_Host *shost = dev_to_shost(parent); struct device *dev = NULL; unsignedlong flags; constint size = sizeof(struct scsi_target)
+ shost->transportt->target_size; struct scsi_target *starget; struct scsi_target *found_target; int error, ref_got;
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(unsignedchar *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.
**/ staticint scsi_probe_lun(struct scsi_device *sdev, unsignedchar *inq_result, int result_len, blist_flags_t *bflags)
{ unsignedchar 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,
}; conststruct 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;
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;
}
/* * 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.
*/ elseif (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;
}
}
/* 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
**/ staticint scsi_add_lun(struct scsi_device *sdev, unsignedchar *inq_result,
blist_flags_t *bflags, int async)
{ conststruct 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->is_ata = strncmp(sdev->vendor, "ATA ", 8) == 0; if (sdev->is_ata) { /* * 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;
}
/* * 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, (unsignedint)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.
*/
/* * 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;
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; elseif (*bflags & BLIST_MAX_1024)
lim.max_hw_sectors = 1024;
if (hostt->sdev_configure)
ret = hostt->sdev_configure(sdev, &lim); 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 ->sdev_configure. * * Set up budget map again since memory consumption of the map depends * on actual queue depth.
*/ if (hostt->sdev_configure)
scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth);
if (sdev->scsi_level >= SCSI_3)
scsi_attach_vpd(sdev);
/* * 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
*/ staticunsignedchar *scsi_inq_str(unsignedchar *buf, unsignedchar *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
**/ staticint 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; unsignedchar *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);
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, { unsignedchar vend[9]; unsignedchar mod[17];
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.
**/ staticvoid 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);
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
**/ staticint scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, enum scsi_scan_mode rescan)
{ unsignedchar scsi_cmd[MAX_COMMAND_SIZE]; unsignedint length;
u64 lun; unsignedint 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,
}; conststruct 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]);
/* * 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);
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);
/* * 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", (unsignedlonglong)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;
}
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);
/** * scsi_add_device - creates a new SCSI (LU) instance * @host: the &Scsi_Host instance where the device is located * @channel: target channel number (rarely other than %0) * @target: target id number * @lun: LUN of target device * * Probe for a specific LUN and add it if found. * * Notes: This call is usually performed internally during a SCSI * bus scan when an HBA is added (i.e. scsi_scan_host()). So it * should only be called if the HBA becomes aware of a new SCSI * device (LU) after scsi_scan_host() has completed. If successful * this call can lead to sdev_init() and sdev_configure() callbacks * into the LLD. * * Return: %0 on success or negative error code on failure
*/ 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);
int scsi_resume_device(struct scsi_device *sdev)
{ struct device *dev = &sdev->sdev_gendev; 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;
}
if (dev->driver && try_module_get(dev->driver->owner)) { struct scsi_driver *drv = to_scsi_driver(dev->driver);
if (drv->resume)
ret = drv->resume(dev);
module_put(dev->driver->owner);
}
unlock:
device_unlock(dev);
return ret;
}
EXPORT_SYMBOL(scsi_resume_device);
int scsi_rescan_device(struct scsi_device *sdev)
{ struct device *dev = &sdev->sdev_gendev; 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);
}
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, unsignedint channel, unsignedint 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 (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);
}
return 0;
}
EXPORT_SYMBOL(scsi_scan_host_selected); staticvoid 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.
*/ staticstruct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
{ struct async_scan_data *data = NULL; unsignedlong 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);
/** * 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.
*/ staticvoid scsi_finish_async_scan(struct async_scan_data *data)
{ struct Scsi_Host *shost; unsignedlong 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;
}
/** * scsi_scan_host - scan the given adapter * @shost: adapter to scan * * Notes: Should be called after scsi_add_host()
**/ 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);
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