diff options
Diffstat (limited to 'drivers/scsi/scsi_scan.c')
| -rw-r--r-- | drivers/scsi/scsi_scan.c | 2000 |
1 files changed, 2000 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c new file mode 100644 index 000000000..bab00b65b --- /dev/null +++ b/drivers/scsi/scsi_scan.c @@ -0,0 +1,2000 @@ +// 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_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, + SCSI_TIMEOUT, 3, NULL); +} + +static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, + unsigned int depth) +{ + int new_shift = sbitmap_calculate_shift(depth); + bool need_alloc = !sdev->budget_map.map; + bool need_free = false; + int ret; + struct sbitmap sb_backup; + + 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 ->slave_configure + */ + if (!need_alloc && new_shift != sdev->budget_map.shift) + need_alloc = need_free = true; + + if (!need_alloc) + return 0; + + /* + * Request queue has to be frozen for reallocating budget map, + * and here disk isn't added yet, so freezing is pretty fast + */ + if (need_free) { + blk_mq_freeze_queue(sdev->request_queue); + sb_backup = sdev->budget_map; + } + ret = sbitmap_init_node(&sdev->budget_map, + scsi_device_max_queue_depth(sdev), + new_shift, GFP_KERNEL, + sdev->request_queue->node, false, true); + if (!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); + + sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, + GFP_KERNEL); + if (!sdev) + goto out; + + sdev->vendor = scsi_null_device_strs; + sdev->model = scsi_null_device_strs; + sdev->rev = scsi_null_device_strs; + sdev->host = shost; + sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; + sdev->id = starget->id; + sdev->lun = lun; + sdev->channel = starget->channel; + mutex_init(&sdev->state_mutex); + sdev->sdev_state = SDEV_CREATED; + INIT_LIST_HEAD(&sdev->siblings); + INIT_LIST_HEAD(&sdev->same_target_siblings); + INIT_LIST_HEAD(&sdev->starved_entry); + INIT_LIST_HEAD(&sdev->event_list); + spin_lock_init(&sdev->list_lock); + mutex_init(&sdev->inquiry_mutex); + INIT_WORK(&sdev->event_work, scsi_evt_thread); + INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); + + sdev->sdev_gendev.parent = get_device(&starget->dev); + sdev->sdev_target = starget; + + /* usually NULL and set by ->slave_alloc instead */ + sdev->hostdata = hostdata; + + /* if the device needs this changing, it may do so in the + * slave_configure function */ + sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; + + /* + * Some low level driver could use device->type + */ + sdev->type = -1; + + /* + * Assume that the device will have handshaking problems, + * and then fix this field later if it turns out it + * doesn't + */ + sdev->borken = 1; + + sdev->sg_reserved_size = INT_MAX; + + q = blk_mq_init_queue(&sdev->host->tag_set); + if (IS_ERR(q)) { + /* release fn is set up in scsi_sysfs_device_initialise, so + * have to free and put manually here */ + put_device(&starget->dev); + kfree(sdev); + goto out; + } + kref_get(&sdev->host->tagset_refcnt); + sdev->request_queue = q; + q->queuedata = sdev; + __scsi_init_queue(sdev->host, q); + WARN_ON_ONCE(!blk_get_queue(q)); + + depth = sdev->host->cmd_per_lun ?: 1; + + /* + * Use .can_queue as budget map's depth because we have to + * support adjusting queue depth from sysfs. Meantime use + * default device queue depth to figure out sbitmap shift + * since we use this queue depth most of times. + */ + if (scsi_realloc_sdev_budget_map(sdev, depth)) { + put_device(&starget->dev); + kfree(sdev); + goto out; + } + + scsi_change_queue_depth(sdev, depth); + + scsi_sysfs_device_initialize(sdev); + + if (shost->hostt->slave_alloc) { + ret = shost->hostt->slave_alloc(sdev); + if (ret) { + /* + * if LLDD reports slave not present, don't clutter + * console with alloc failure messages + */ + if (ret == -ENXIO) + display_failure_msg = 0; + goto out_device_destroy; + } + } + + return sdev; + +out_device_destroy: + __scsi_remove_device(sdev); +out: + if (display_failure_msg) + printk(ALLOC_FAILURE_MSG, __func__); + return NULL; +} + +static void scsi_target_destroy(struct scsi_target *starget) +{ + struct device *dev = &starget->dev; + struct Scsi_Host *shost = dev_to_shost(dev->parent); + unsigned long flags; + + BUG_ON(starget->state == STARGET_DEL); + starget->state = STARGET_DEL; + transport_destroy_device(dev); + spin_lock_irqsave(shost->host_lock, flags); + if (shost->hostt->target_destroy) + shost->hostt->target_destroy(starget); + list_del_init(&starget->siblings); + spin_unlock_irqrestore(shost->host_lock, flags); + put_device(dev); +} + +static void scsi_target_dev_release(struct device *dev) +{ + struct device *parent = dev->parent; + struct scsi_target *starget = to_scsi_target(dev); + + kfree(starget); + put_device(parent); +} + +static struct device_type scsi_target_type = { + .name = "scsi_target", + .release = scsi_target_dev_release, +}; + +int scsi_is_target_device(const struct device *dev) +{ + return dev->type == &scsi_target_type; +} +EXPORT_SYMBOL(scsi_is_target_device); + +static struct scsi_target *__scsi_find_target(struct device *parent, + int channel, uint id) +{ + struct scsi_target *starget, *found_starget = NULL; + struct Scsi_Host *shost = dev_to_shost(parent); + /* + * Search for an existing target for this sdev. + */ + list_for_each_entry(starget, &shost->__targets, siblings) { + if (starget->id == id && + starget->channel == channel) { + found_starget = starget; + break; + } + } + if (found_starget) + get_device(&found_starget->dev); + + return found_starget; +} + +/** + * scsi_target_reap_ref_release - remove target from visibility + * @kref: the reap_ref in the target being released + * + * Called on last put of reap_ref, which is the indication that no device + * under this target is visible anymore, so render the target invisible in + * sysfs. Note: we have to be in user context here because the target reaps + * should be done in places where the scsi device visibility is being removed. + */ +static void scsi_target_reap_ref_release(struct kref *kref) +{ + struct scsi_target *starget + = container_of(kref, struct scsi_target, reap_ref); + + /* + * if we get here and the target is still in a CREATED state that + * means it was allocated but never made visible (because a scan + * turned up no LUNs), so don't call device_del() on it. + */ + if ((starget->state != STARGET_CREATED) && + (starget->state != STARGET_CREATED_REMOVE)) { + transport_remove_device(&starget->dev); + device_del(&starget->dev); + } + scsi_target_destroy(starget); +} + +static void scsi_target_reap_ref_put(struct scsi_target *starget) +{ + kref_put(&starget->reap_ref, scsi_target_reap_ref_release); +} + +/** + * scsi_alloc_target - allocate a new or find an existing target + * @parent: parent of the target (need not be a scsi host) + * @channel: target channel number (zero if no channels) + * @id: target id number + * + * Return an existing target if one exists, provided it hasn't already + * gone into STARGET_DEL state, otherwise allocate a new target. + * + * The target is returned with an incremented reference, so the caller + * is responsible for both reaping and doing a last put + */ +static struct scsi_target *scsi_alloc_target(struct device *parent, + int channel, uint id) +{ + struct Scsi_Host *shost = dev_to_shost(parent); + struct device *dev = NULL; + unsigned long flags; + const int size = sizeof(struct scsi_target) + + shost->transportt->target_size; + struct scsi_target *starget; + struct scsi_target *found_target; + int error, ref_got; + + starget = kzalloc(size, GFP_KERNEL); + if (!starget) { + printk(KERN_ERR "%s: allocation failure\n", __func__); + return NULL; + } + dev = &starget->dev; + device_initialize(dev); + kref_init(&starget->reap_ref); + dev->parent = get_device(parent); + dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); + dev->bus = &scsi_bus_type; + dev->type = &scsi_target_type; + scsi_enable_async_suspend(dev); + starget->id = id; + starget->channel = channel; + starget->can_queue = 0; + INIT_LIST_HEAD(&starget->siblings); + INIT_LIST_HEAD(&starget->devices); + starget->state = STARGET_CREATED; + starget->scsi_level = SCSI_2; + starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; + retry: + spin_lock_irqsave(shost->host_lock, flags); + + found_target = __scsi_find_target(parent, channel, id); + if (found_target) + goto found; + + list_add_tail(&starget->siblings, &shost->__targets); + spin_unlock_irqrestore(shost->host_lock, flags); + /* allocate and add */ + transport_setup_device(dev); + if (shost->hostt->target_alloc) { + error = shost->hostt->target_alloc(starget); + + if(error) { + if (error != -ENXIO) + dev_err(dev, "target allocation failed, error %d\n", error); + /* don't want scsi_target_reap to do the final + * put because it will be under the host lock */ + scsi_target_destroy(starget); + return NULL; + } + } + get_device(dev); + + return starget; + + found: + /* + * release routine already fired if kref is zero, so if we can still + * take the reference, the target must be alive. If we can't, it must + * be dying and we need to wait for a new target + */ + ref_got = kref_get_unless_zero(&found_target->reap_ref); + + spin_unlock_irqrestore(shost->host_lock, flags); + if (ref_got) { + put_device(dev); + return found_target; + } + /* + * Unfortunately, we found a dying target; need to wait until it's + * dead before we can get a new one. There is an anomaly here. We + * *should* call scsi_target_reap() to balance the kref_get() of the + * reap_ref above. However, since the target being released, it's + * already invisible and the reap_ref is irrelevant. If we call + * scsi_target_reap() we might spuriously do another device_del() on + * an already invisible target. + */ + put_device(&found_target->dev); + /* + * length of time is irrelevant here, we just want to yield the CPU + * for a tick to avoid busy waiting for the target to die. + */ + msleep(1); + goto retry; +} + +/** + * scsi_target_reap - check to see if target is in use and destroy if not + * @starget: target to be checked + * + * This is used after removing a LUN or doing a last put of the target + * it checks atomically that nothing is using the target and removes + * it if so. + */ +void scsi_target_reap(struct scsi_target *starget) +{ + /* + * serious problem if this triggers: STARGET_DEL is only set in the if + * the reap_ref drops to zero, so we're trying to do another final put + * on an already released kref + */ + BUG_ON(starget->state == STARGET_DEL); + scsi_target_reap_ref_put(starget); +} + +/** + * scsi_sanitize_inquiry_string - remove non-graphical chars from an + * INQUIRY result string + * @s: INQUIRY result string to sanitize + * @len: length of the string + * + * Description: + * The SCSI spec says that INQUIRY vendor, product, and revision + * strings must consist entirely of graphic ASCII characters, + * padded on the right with spaces. Since not all devices obey + * this rule, we will replace non-graphic or non-ASCII characters + * with spaces. Exception: a NUL character is interpreted as a + * string terminator, so all the following characters are set to + * spaces. + **/ +void scsi_sanitize_inquiry_string(unsigned char *s, int len) +{ + int terminated = 0; + + for (; len > 0; (--len, ++s)) { + if (*s == 0) + terminated = 1; + if (terminated || *s < 0x20 || *s > 0x7e) + *s = ' '; + } +} +EXPORT_SYMBOL(scsi_sanitize_inquiry_string); + +/** + * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY + * @sdev: scsi_device to probe + * @inq_result: area to store the INQUIRY result + * @result_len: len of inq_result + * @bflags: store any bflags found here + * + * Description: + * Probe the lun associated with @req using a standard SCSI INQUIRY; + * + * If the INQUIRY is successful, zero is returned and the + * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length + * are copied to the scsi_device any flags value is stored in *@bflags. + **/ +static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, + int result_len, blist_flags_t *bflags) +{ + unsigned char scsi_cmd[MAX_COMMAND_SIZE]; + int first_inquiry_len, try_inquiry_len, next_inquiry_len; + int response_len = 0; + int pass, count, result; + struct scsi_sense_hdr sshdr; + + *bflags = 0; + + /* Perform up to 3 passes. The first pass uses a conservative + * transfer length of 36 unless sdev->inquiry_len specifies a + * different value. */ + first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; + try_inquiry_len = first_inquiry_len; + pass = 1; + + next_pass: + SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, + "scsi scan: INQUIRY pass %d length %d\n", + pass, try_inquiry_len)); + + /* Each pass gets up to three chances to ignore Unit Attention */ + for (count = 0; count < 3; ++count) { + int resid; + + memset(scsi_cmd, 0, 6); + scsi_cmd[0] = INQUIRY; + scsi_cmd[4] = (unsigned char) try_inquiry_len; + + memset(inq_result, 0, try_inquiry_len); + + result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, + inq_result, try_inquiry_len, &sshdr, + HZ / 2 + HZ * scsi_inq_timeout, 3, + &resid); + + SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, + "scsi scan: INQUIRY %s with code 0x%x\n", + result ? "failed" : "successful", result)); + + if (result > 0) { + /* + * not-ready to ready transition [asc/ascq=0x28/0x0] + * or power-on, reset [asc/ascq=0x29/0x0], continue. + * INQUIRY should not yield UNIT_ATTENTION + * but many buggy devices do so anyway. + */ + if (scsi_status_is_check_condition(result) && + scsi_sense_valid(&sshdr)) { + if ((sshdr.sense_key == UNIT_ATTENTION) && + ((sshdr.asc == 0x28) || + (sshdr.asc == 0x29)) && + (sshdr.ascq == 0)) + continue; + } + } else if (result == 0) { + /* + * if nothing was transferred, we try + * again. It's a workaround for some USB + * devices. + */ + if (resid == try_inquiry_len) + continue; + } + break; + } + + if (result == 0) { + scsi_sanitize_inquiry_string(&inq_result[8], 8); + scsi_sanitize_inquiry_string(&inq_result[16], 16); + scsi_sanitize_inquiry_string(&inq_result[32], 4); + + response_len = inq_result[4] + 5; + if (response_len > 255) + response_len = first_inquiry_len; /* sanity */ + + /* + * Get any flags for this device. + * + * XXX add a bflags to scsi_device, and replace the + * corresponding bit fields in scsi_device, so bflags + * need not be passed as an argument. + */ + *bflags = scsi_get_device_flags(sdev, &inq_result[8], + &inq_result[16]); + + /* When the first pass succeeds we gain information about + * what larger transfer lengths might work. */ + if (pass == 1) { + if (BLIST_INQUIRY_36 & *bflags) + next_inquiry_len = 36; + /* + * 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] & 0x07; + if (sdev->scsi_level >= 2 || + (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) + sdev->scsi_level++; + sdev->sdev_target->scsi_level = sdev->scsi_level; + + /* + * If SCSI-2 or lower, and if the transport requires it, + * store the LUN value in CDB[1]. + */ + sdev->lun_in_cdb = 0; + if (sdev->scsi_level <= SCSI_2 && + sdev->scsi_level != SCSI_UNKNOWN && + !sdev->host->no_scsi2_lun_in_cdb) + sdev->lun_in_cdb = 1; + + return 0; +} + +/** + * scsi_add_lun - allocate and fully initialze a scsi_device + * @sdev: holds information to be stored in the new scsi_device + * @inq_result: holds the result of a previous INQUIRY to the LUN + * @bflags: black/white list flag + * @async: 1 if this device is being scanned asynchronously + * + * Description: + * Initialize the scsi_device @sdev. Optionally set fields based + * on values in *@bflags. + * + * Return: + * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device + * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized + **/ +static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, + blist_flags_t *bflags, int async) +{ + int ret; + + /* + * XXX do not save the inquiry, since it can change underneath us, + * save just vendor/model/rev. + * + * Rather than save it and have an ioctl that retrieves the saved + * value, have an ioctl that executes the same INQUIRY code used + * in scsi_probe_lun, let user level programs doing INQUIRY + * scanning run at their own risk, or supply a user level program + * that can correctly scan. + */ + + /* + * Copy at least 36 bytes of INQUIRY data, so that we don't + * dereference unallocated memory when accessing the Vendor, + * Product, and Revision strings. Badly behaved devices may set + * the INQUIRY Additional Length byte to a small value, indicating + * these strings are invalid, but often they contain plausible data + * nonetheless. It doesn't matter if the device sent < 36 bytes + * total, since scsi_probe_lun() initializes inq_result with 0s. + */ + sdev->inquiry = kmemdup(inq_result, + max_t(size_t, sdev->inquiry_len, 36), + GFP_KERNEL); + if (sdev->inquiry == NULL) + return SCSI_SCAN_NO_RESPONSE; + + sdev->vendor = (char *) (sdev->inquiry + 8); + sdev->model = (char *) (sdev->inquiry + 16); + sdev->rev = (char *) (sdev->inquiry + 32); + + if (strncmp(sdev->vendor, "ATA ", 8) == 0) { + /* + * sata emulation layer device. This is a hack to work around + * the SATL power management specifications which state that + * when the SATL detects the device has gone into standby + * mode, it shall respond with NOT READY. + */ + sdev->allow_restart = 1; + } + + if (*bflags & BLIST_ISROM) { + sdev->type = TYPE_ROM; + sdev->removable = 1; + } else { + sdev->type = (inq_result[0] & 0x1f); + sdev->removable = (inq_result[1] & 0x80) >> 7; + + /* + * some devices may respond with wrong type for + * well-known logical units. Force well-known type + * to enumerate them correctly. + */ + if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { + sdev_printk(KERN_WARNING, sdev, + "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", + __func__, sdev->type, (unsigned int)sdev->lun); + sdev->type = TYPE_WLUN; + } + + } + + if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { + /* RBC and MMC devices can return SCSI-3 compliance and yet + * still not support REPORT LUNS, so make them act as + * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is + * specifically set */ + if ((*bflags & BLIST_REPORTLUN2) == 0) + *bflags |= BLIST_NOREPORTLUN; + } + + /* + * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI + * spec says: The device server is capable of supporting the + * specified peripheral device type on this logical unit. However, + * the physical device is not currently connected to this logical + * unit. + * + * The above is vague, as it implies that we could treat 001 and + * 011 the same. Stay compatible with previous code, and create a + * scsi_device for a PQ of 1 + * + * Don't set the device offline here; rather let the upper + * level drivers eval the PQ to decide whether they should + * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. + */ + + sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; + sdev->lockable = sdev->removable; + sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); + + if (sdev->scsi_level >= SCSI_3 || + (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) + sdev->ppr = 1; + if (inq_result[7] & 0x60) + sdev->wdtr = 1; + if (inq_result[7] & 0x10) + sdev->sdtr = 1; + + sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " + "ANSI: %d%s\n", scsi_device_type(sdev->type), + sdev->vendor, sdev->model, sdev->rev, + sdev->inq_periph_qual, inq_result[2] & 0x07, + (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); + + if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && + !(*bflags & BLIST_NOTQ)) { + sdev->tagged_supported = 1; + sdev->simple_tags = 1; + } + + /* + * Some devices (Texel CD ROM drives) have handshaking problems + * when used with the Seagate controllers. borken is initialized + * to 1, and then set it to 0 here. + */ + if ((*bflags & BLIST_BORKEN) == 0) + sdev->borken = 0; + + if (*bflags & BLIST_NO_ULD_ATTACH) + sdev->no_uld_attach = 1; + + /* + * Apparently some really broken devices (contrary to the SCSI + * standards) need to be selected without asserting ATN + */ + if (*bflags & BLIST_SELECT_NO_ATN) + sdev->select_no_atn = 1; + + /* + * Maximum 512 sector transfer length + * broken RA4x00 Compaq Disk Array + */ + if (*bflags & BLIST_MAX_512) + blk_queue_max_hw_sectors(sdev->request_queue, 512); + /* + * Max 1024 sector transfer length for targets that report incorrect + * max/optimal lengths and relied on the old block layer safe default + */ + else if (*bflags & BLIST_MAX_1024) + blk_queue_max_hw_sectors(sdev->request_queue, 1024); + + /* + * Some devices may not want to have a start command automatically + * issued when a device is added. + */ + if (*bflags & BLIST_NOSTARTONADD) + sdev->no_start_on_add = 1; + + if (*bflags & BLIST_SINGLELUN) + scsi_target(sdev)->single_lun = 1; + + sdev->use_10_for_rw = 1; + + /* some devices don't like REPORT SUPPORTED OPERATION CODES + * 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); + + if (sdev->host->hostt->slave_configure) { + ret = sdev->host->hostt->slave_configure(sdev); + if (ret) { + /* + * if LLDD reports slave not present, don't clutter + * console with alloc failure messages + */ + if (ret != -ENXIO) { + sdev_printk(KERN_ERR, sdev, + "failed to configure device\n"); + } + return SCSI_SCAN_NO_RESPONSE; + } + + /* + * The queue_depth is often changed in ->slave_configure. + * Set up budget map again since memory consumption of + * the map depends on actual queue depth. + */ + scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth); + } + + if (sdev->scsi_level >= SCSI_3) + scsi_attach_vpd(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; + unsigned int retries; + int result; + struct scsi_lun *lunp, *lun_data; + struct scsi_sense_hdr sshdr; + struct scsi_device *sdev; + struct Scsi_Host *shost = dev_to_shost(&starget->dev); + int ret = 0; + + /* + * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. + * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does + * support more than 8 LUNs. + * 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. + */ + for (retries = 0; retries < 3; retries++) { + SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, + "scsi scan: Sending REPORT LUNS to (try %d)\n", + retries)); + + result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, + lun_data, length, &sshdr, + SCSI_REPORT_LUNS_TIMEOUT, 3, NULL); + + SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, + "scsi scan: REPORT LUNS" + " %s (try %d) result 0x%x\n", + result ? "failed" : "successful", + retries, result)); + if (result == 0) + break; + else if (scsi_sense_valid(&sshdr)) { + if (sshdr.sense_key != UNIT_ATTENTION) + break; + } + } + + if (result) { + /* + * The device probably does not support a REPORT LUN command + */ + ret = 1; + goto out_err; + } + + /* + * Get the length from the first four bytes of lun_data. + */ + 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, 1, 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(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); + + 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); + +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, 0); + } +} + +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); +} + |