scsi_sysfs.c

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/*
 * scsi_sysfs.c
 *
 * SCSI sysfs interface routines.
 *
 * Created to pull SCSI mid layer sysfs routines into one file.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>

#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_driver.h>

#include "scsi_priv.h"
#include "scsi_logging.h"

static struct device_type scsi_dev_type;

static const struct {
    enum scsi_device_state  value;
    char            *name;
} sdev_states[] = {
    { SDEV_CREATED, "created" },
    { SDEV_RUNNING, "running" },
    { SDEV_CANCEL, "cancel" },
    { SDEV_DEL, "deleted" },
    { SDEV_QUIESCE, "quiesce" },
    { SDEV_OFFLINE, "offline" },
    { SDEV_TRANSPORT_OFFLINE, "transport-offline" },
    { SDEV_BLOCK,   "blocked" },
    { SDEV_CREATED_BLOCK, "created-blocked" },
};

const char *scsi_device_state_name(enum scsi_device_state state)
{
    int i;
    char *name = NULL;

    for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
        if (sdev_states[i].value == state) {
            name = sdev_states[i].name;
            break;
        }
    }
    return name;
}

static const struct {
    enum scsi_host_state    value;
    char            *name;
} shost_states[] = {
    { SHOST_CREATED, "created" },
    { SHOST_RUNNING, "running" },
    { SHOST_CANCEL, "cancel" },
    { SHOST_DEL, "deleted" },
    { SHOST_RECOVERY, "recovery" },
    { SHOST_CANCEL_RECOVERY, "cancel/recovery" },
    { SHOST_DEL_RECOVERY, "deleted/recovery", },
};
const char *scsi_host_state_name(enum scsi_host_state state)
{
    int i;
    char *name = NULL;

    for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
        if (shost_states[i].value == state) {
            name = shost_states[i].name;
            break;
        }
    }
    return name;
}

static int check_set(unsigned int *val, char *src)
{
    char *last;

    if (strncmp(src, "-", 20) == 0) {
        *val = SCAN_WILD_CARD;
    } else {
        /*
         * Doesn't check for int overflow
         */
        *val = simple_strtoul(src, &last, 0);
        if (*last != '\0')
            return 1;
    }
    return 0;
}

static int scsi_scan(struct Scsi_Host *shost, const char *str)
{
    char s1[15], s2[15], s3[15], junk;
    unsigned int channel, id, lun;
    int res;

    res = sscanf(str, "%10s %10s %10s %c", s1, s2, s3, &junk);
    if (res != 3)
        return -EINVAL;
    if (check_set(&channel, s1))
        return -EINVAL;
    if (check_set(&id, s2))
        return -EINVAL;
    if (check_set(&lun, s3))
        return -EINVAL;
    if (shost->transportt->user_scan)
        res = shost->transportt->user_scan(shost, channel, id, lun);
    else
        res = scsi_scan_host_selected(shost, channel, id, lun, 1);
    return res;
}

/*
 * shost_show_function: macro to create an attr function that can be used to
 * show a non-bit field.
 */
#define shost_show_function(name, field, format_string)         \
static ssize_t                              \
show_##name (struct device *dev, struct device_attribute *attr,     \
         char *buf)                         \
{                                   \
    struct Scsi_Host *shost = class_to_shost(dev);          \
    return snprintf (buf, 20, format_string, shost->field);     \
}

/*
 * shost_rd_attr: macro to create a function and attribute variable for a
 * read only field.
 */
#define shost_rd_attr2(name, field, format_string)          \
    shost_show_function(name, field, format_string)         \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);

#define shost_rd_attr(field, format_string) \
shost_rd_attr2(field, field, format_string)

/*
 * Create the actual show/store functions and data structures.
 */

static ssize_t
store_scan(struct device *dev, struct device_attribute *attr,
       const char *buf, size_t count)
{
    struct Scsi_Host *shost = class_to_shost(dev);
    int res;

    res = scsi_scan(shost, buf);
    if (res == 0)
        res = count;
    return res;
};
static DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);

static ssize_t
store_shost_state(struct device *dev, struct device_attribute *attr,
          const char *buf, size_t count)
{
    int i;
    struct Scsi_Host *shost = class_to_shost(dev);
    enum scsi_host_state state = 0;

    for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
        const int len = strlen(shost_states[i].name);
        if (strncmp(shost_states[i].name, buf, len) == 0 &&
           buf[len] == '\n') {
            state = shost_states[i].value;
            break;
        }
    }
    if (!state)
        return -EINVAL;

    if (scsi_host_set_state(shost, state))
        return -EINVAL;
    return count;
}

static ssize_t
show_shost_state(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct Scsi_Host *shost = class_to_shost(dev);
    const char *name = scsi_host_state_name(shost->shost_state);

    if (!name)
        return -EINVAL;

    return snprintf(buf, 20, "%s\n", name);
}

/* DEVICE_ATTR(state) clashes with dev_attr_state for sdev */
struct device_attribute dev_attr_hstate =
    __ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);

static ssize_t
show_shost_mode(unsigned int mode, char *buf)
{
    ssize_t len = 0;

    if (mode & MODE_INITIATOR)
        len = sprintf(buf, "%s", "Initiator");

    if (mode & MODE_TARGET)
        len += sprintf(buf + len, "%s%s", len ? ", " : "", "Target");

    len += sprintf(buf + len, "\n");

    return len;
}

static ssize_t
show_shost_supported_mode(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    struct Scsi_Host *shost = class_to_shost(dev);
    unsigned int supported_mode = shost->hostt->supported_mode;

    if (supported_mode == MODE_UNKNOWN)
        /* by default this should be initiator */
        supported_mode = MODE_INITIATOR;

    return show_shost_mode(supported_mode, buf);
}

static DEVICE_ATTR(supported_mode, S_IRUGO | S_IWUSR, show_shost_supported_mode, NULL);

static ssize_t
show_shost_active_mode(struct device *dev,
               struct device_attribute *attr, char *buf)
{
    struct Scsi_Host *shost = class_to_shost(dev);

    if (shost->active_mode == MODE_UNKNOWN)
        return snprintf(buf, 20, "unknown\n");
    else
        return show_shost_mode(shost->active_mode, buf);
}

static DEVICE_ATTR(active_mode, S_IRUGO | S_IWUSR, show_shost_active_mode, NULL);

static int check_reset_type(char *str)
{
    if (strncmp(str, "adapter", 10) == 0)
        return SCSI_ADAPTER_RESET;
    else if (strncmp(str, "firmware", 10) == 0)
        return SCSI_FIRMWARE_RESET;
    else
        return 0;
}

static ssize_t
store_host_reset(struct device *dev, struct device_attribute *attr,
        const char *buf, size_t count)
{
    struct Scsi_Host *shost = class_to_shost(dev);
    struct scsi_host_template *sht = shost->hostt;
    int ret = -EINVAL;
    char str[10];
    int type;

    sscanf(buf, "%s", str);
    type = check_reset_type(str);

    if (!type)
        goto exit_store_host_reset;

    if (sht->host_reset)
        ret = sht->host_reset(shost, type);

exit_store_host_reset:
    if (ret == 0)
        ret = count;
    return ret;
}

static DEVICE_ATTR(host_reset, S_IWUSR, NULL, store_host_reset);

shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
shost_rd_attr(can_queue, "%hd\n");
shost_rd_attr(sg_tablesize, "%hu\n");
shost_rd_attr(sg_prot_tablesize, "%hu\n");
shost_rd_attr(unchecked_isa_dma, "%d\n");
shost_rd_attr(prot_capabilities, "%u\n");
shost_rd_attr(prot_guard_type, "%hd\n");
shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");

static struct attribute *scsi_sysfs_shost_attrs[] = {
    &dev_attr_unique_id.attr,
    &dev_attr_host_busy.attr,
    &dev_attr_cmd_per_lun.attr,
    &dev_attr_can_queue.attr,
    &dev_attr_sg_tablesize.attr,
    &dev_attr_sg_prot_tablesize.attr,
    &dev_attr_unchecked_isa_dma.attr,
    &dev_attr_proc_name.attr,
    &dev_attr_scan.attr,
    &dev_attr_hstate.attr,
    &dev_attr_supported_mode.attr,
    &dev_attr_active_mode.attr,
    &dev_attr_prot_capabilities.attr,
    &dev_attr_prot_guard_type.attr,
    &dev_attr_host_reset.attr,
    NULL
};

struct attribute_group scsi_shost_attr_group = {
    .attrs =    scsi_sysfs_shost_attrs,
};

const struct attribute_group *scsi_sysfs_shost_attr_groups[] = {
    &scsi_shost_attr_group,
    NULL
};

static void scsi_device_cls_release(struct device *class_dev)
{
    struct scsi_device *sdev;

    sdev = class_to_sdev(class_dev);
    put_device(&sdev->sdev_gendev);
}

static void scsi_device_dev_release_usercontext(struct work_struct *work)
{
    struct scsi_device *sdev;
    struct device *parent;
    struct scsi_target *starget;
    struct list_head *this, *tmp;
    unsigned long flags;

    sdev = container_of(work, struct scsi_device, ew.work);

    parent = sdev->sdev_gendev.parent;
    starget = to_scsi_target(parent);

    spin_lock_irqsave(sdev->host->host_lock, flags);
    starget->reap_ref++;
    list_del(&sdev->siblings);
    list_del(&sdev->same_target_siblings);
    list_del(&sdev->starved_entry);
    spin_unlock_irqrestore(sdev->host->host_lock, flags);

    cancel_work_sync(&sdev->event_work);

    list_for_each_safe(this, tmp, &sdev->event_list) {
        struct scsi_event *evt;

        evt = list_entry(this, struct scsi_event, node);
        list_del(&evt->node);
        kfree(evt);
    }

    blk_put_queue(sdev->request_queue);
    /* NULL queue means the device can't be used */
    sdev->request_queue = NULL;

    scsi_target_reap(scsi_target(sdev));

    kfree(sdev->inquiry);
    kfree(sdev);

    if (parent)
        put_device(parent);
}

static void scsi_device_dev_release(struct device *dev)
{
    struct scsi_device *sdp = to_scsi_device(dev);
    execute_in_process_context(scsi_device_dev_release_usercontext,
                   &sdp->ew);
}

static struct class sdev_class = {
    .name       = "scsi_device",
    .dev_release    = scsi_device_cls_release,
};

/* all probing is done in the individual ->probe routines */
static int scsi_bus_match(struct device *dev, struct device_driver *gendrv)
{
    struct scsi_device *sdp;

    if (dev->type != &scsi_dev_type)
        return 0;

    sdp = to_scsi_device(dev);
    if (sdp->no_uld_attach)
        return 0;
    return (sdp->inq_periph_qual == SCSI_INQ_PQ_CON)? 1: 0;
}

static int scsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
    struct scsi_device *sdev;

    if (dev->type != &scsi_dev_type)
        return 0;

    sdev = to_scsi_device(dev);

    add_uevent_var(env, "MODALIAS=" SCSI_DEVICE_MODALIAS_FMT, sdev->type);
    return 0;
}

struct bus_type scsi_bus_type = {
        .name       = "scsi",
        .match      = scsi_bus_match,
    .uevent     = scsi_bus_uevent,
#ifdef CONFIG_PM
    .pm     = &scsi_bus_pm_ops,
#endif
};
EXPORT_SYMBOL_GPL(scsi_bus_type);

int scsi_sysfs_register(void)
{
    int error;

    error = bus_register(&scsi_bus_type);
    if (!error) {
        error = class_register(&sdev_class);
        if (error)
            bus_unregister(&scsi_bus_type);
    }

    return error;
}

void scsi_sysfs_unregister(void)
{
    class_unregister(&sdev_class);
    bus_unregister(&scsi_bus_type);
}

/*
 * sdev_show_function: macro to create an attr function that can be used to
 * show a non-bit field.
 */
#define sdev_show_function(field, format_string)                \
static ssize_t                              \
sdev_show_##field (struct device *dev, struct device_attribute *attr,   \
           char *buf)                       \
{                                   \
    struct scsi_device *sdev;                   \
    sdev = to_scsi_device(dev);                 \
    return snprintf (buf, 20, format_string, sdev->field);      \
}                                   \

/*
 * sdev_rd_attr: macro to create a function and attribute variable for a
 * read only field.
 */
#define sdev_rd_attr(field, format_string)              \
    sdev_show_function(field, format_string)            \
static DEVICE_ATTR(field, S_IRUGO, sdev_show_##field, NULL);


/*
 * sdev_rw_attr: create a function and attribute variable for a
 * read/write field.
 */
#define sdev_rw_attr(field, format_string)              \
    sdev_show_function(field, format_string)                \
                                    \
static ssize_t                              \
sdev_store_##field (struct device *dev, struct device_attribute *attr,  \
            const char *buf, size_t count)          \
{                                   \
    struct scsi_device *sdev;                   \
    sdev = to_scsi_device(dev);                 \
    sscanf (buf, format_string, &sdev->field);          \
    return count;                           \
}                                   \
static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);

/* Currently we don't export bit fields, but we might in future,
 * so leave this code in */
#if 0
/*
 * sdev_rd_attr: create a function and attribute variable for a
 * read/write bit field.
 */
#define sdev_rw_attr_bit(field)                     \
    sdev_show_function(field, "%d\n")                   \
                                    \
static ssize_t                              \
sdev_store_##field (struct device *dev, struct device_attribute *attr,  \
            const char *buf, size_t count)          \
{                                   \
    int ret;                            \
    struct scsi_device *sdev;                   \
    ret = scsi_sdev_check_buf_bit(buf);             \
    if (ret >= 0)   {                       \
        sdev = to_scsi_device(dev);             \
        sdev->field = ret;                  \
        ret = count;                        \
    }                               \
    return ret;                         \
}                                   \
static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);

/*
 * scsi_sdev_check_buf_bit: return 0 if buf is "0", return 1 if buf is "1",
 * else return -EINVAL.
 */
static int scsi_sdev_check_buf_bit(const char *buf)
{
    if ((buf[1] == '\0') || ((buf[1] == '\n') && (buf[2] == '\0'))) {
        if (buf[0] == '1')
            return 1;
        else if (buf[0] == '0')
            return 0;
        else 
            return -EINVAL;
    } else
        return -EINVAL;
}
#endif
/*
 * Create the actual show/store functions and data structures.
 */
sdev_rd_attr (device_blocked, "%d\n");
sdev_rd_attr (queue_depth, "%d\n");
sdev_rd_attr (type, "%d\n");
sdev_rd_attr (scsi_level, "%d\n");
sdev_rd_attr (vendor, "%.8s\n");
sdev_rd_attr (model, "%.16s\n");
sdev_rd_attr (rev, "%.4s\n");

/*
 * TODO: can we make these symlinks to the block layer ones?
 */
static ssize_t
sdev_show_timeout (struct device *dev, struct device_attribute *attr, char *buf)
{
    struct scsi_device *sdev;
    sdev = to_scsi_device(dev);
    return snprintf(buf, 20, "%d\n", sdev->request_queue->rq_timeout / HZ);
}

static ssize_t
sdev_store_timeout (struct device *dev, struct device_attribute *attr,
            const char *buf, size_t count)
{
    struct scsi_device *sdev;
    int timeout;
    sdev = to_scsi_device(dev);
    sscanf (buf, "%d\n", &timeout);
    blk_queue_rq_timeout(sdev->request_queue, timeout * HZ);
    return count;
}
static DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR, sdev_show_timeout, sdev_store_timeout);

static ssize_t
store_rescan_field (struct device *dev, struct device_attribute *attr,
            const char *buf, size_t count)
{
    scsi_rescan_device(dev);
    return count;
}
static DEVICE_ATTR(rescan, S_IWUSR, NULL, store_rescan_field);

static void sdev_store_delete_callback(struct device *dev)
{
    scsi_remove_device(to_scsi_device(dev));
}

static ssize_t
sdev_store_delete(struct device *dev, struct device_attribute *attr,
          const char *buf, size_t count)
{
    int rc;

    /* An attribute cannot be unregistered by one of its own methods,
     * so we have to use this roundabout approach.
     */
    rc = device_schedule_callback(dev, sdev_store_delete_callback);
    if (rc)
        count = rc;
    return count;
};
static DEVICE_ATTR(delete, S_IWUSR, NULL, sdev_store_delete);

static ssize_t
store_state_field(struct device *dev, struct device_attribute *attr,
          const char *buf, size_t count)
{
    int i;
    struct scsi_device *sdev = to_scsi_device(dev);
    enum scsi_device_state state = 0;

    for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
        const int len = strlen(sdev_states[i].name);
        if (strncmp(sdev_states[i].name, buf, len) == 0 &&
           buf[len] == '\n') {
            state = sdev_states[i].value;
            break;
        }
    }
    if (!state)
        return -EINVAL;

    if (scsi_device_set_state(sdev, state))
        return -EINVAL;
    return count;
}

static ssize_t
show_state_field(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct scsi_device *sdev = to_scsi_device(dev);
    const char *name = scsi_device_state_name(sdev->sdev_state);

    if (!name)
        return -EINVAL;

    return snprintf(buf, 20, "%s\n", name);
}

static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_state_field, store_state_field);

static ssize_t
show_queue_type_field(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    struct scsi_device *sdev = to_scsi_device(dev);
    const char *name = "none";

    if (sdev->ordered_tags)
        name = "ordered";
    else if (sdev->simple_tags)
        name = "simple";

    return snprintf(buf, 20, "%s\n", name);
}

static DEVICE_ATTR(queue_type, S_IRUGO, show_queue_type_field, NULL);

static ssize_t
show_iostat_counterbits(struct device *dev, struct device_attribute *attr,              char *buf)
{
    return snprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
}

static DEVICE_ATTR(iocounterbits, S_IRUGO, show_iostat_counterbits, NULL);

#define show_sdev_iostat(field)                     \
static ssize_t                              \
show_iostat_##field(struct device *dev, struct device_attribute *attr,  \
            char *buf)                      \
{                                   \
    struct scsi_device *sdev = to_scsi_device(dev);         \
    unsigned long long count = atomic_read(&sdev->field);       \
    return snprintf(buf, 20, "0x%llx\n", count);            \
}                                   \
static DEVICE_ATTR(field, S_IRUGO, show_iostat_##field, NULL)

show_sdev_iostat(iorequest_cnt);
show_sdev_iostat(iodone_cnt);
show_sdev_iostat(ioerr_cnt);

static ssize_t
sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct scsi_device *sdev;
    sdev = to_scsi_device(dev);
    return snprintf (buf, 20, SCSI_DEVICE_MODALIAS_FMT "\n", sdev->type);
}
static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);

#define DECLARE_EVT_SHOW(name, Cap_name)                \
static ssize_t                              \
sdev_show_evt_##name(struct device *dev, struct device_attribute *attr, \
             char *buf)                     \
{                                   \
    struct scsi_device *sdev = to_scsi_device(dev);         \
    int val = test_bit(SDEV_EVT_##Cap_name, sdev->supported_events);\
    return snprintf(buf, 20, "%d\n", val);              \
}

#define DECLARE_EVT_STORE(name, Cap_name)               \
static ssize_t                              \
sdev_store_evt_##name(struct device *dev, struct device_attribute *attr,\
              const char *buf, size_t count)            \
{                                   \
    struct scsi_device *sdev = to_scsi_device(dev);         \
    int val = simple_strtoul(buf, NULL, 0);             \
    if (val == 0)                           \
        clear_bit(SDEV_EVT_##Cap_name, sdev->supported_events); \
    else if (val == 1)                      \
        set_bit(SDEV_EVT_##Cap_name, sdev->supported_events);   \
    else                                \
        return -EINVAL;                     \
    return count;                           \
}

#define DECLARE_EVT(name, Cap_name)                 \
    DECLARE_EVT_SHOW(name, Cap_name)                \
    DECLARE_EVT_STORE(name, Cap_name)               \
    static DEVICE_ATTR(evt_##name, S_IRUGO, sdev_show_evt_##name,   \
               sdev_store_evt_##name);
#define REF_EVT(name) &dev_attr_evt_##name.attr

DECLARE_EVT(media_change, MEDIA_CHANGE)

/* Default template for device attributes.  May NOT be modified */
static struct attribute *scsi_sdev_attrs[] = {
    &dev_attr_device_blocked.attr,
    &dev_attr_type.attr,
    &dev_attr_scsi_level.attr,
    &dev_attr_vendor.attr,
    &dev_attr_model.attr,
    &dev_attr_rev.attr,
    &dev_attr_rescan.attr,
    &dev_attr_delete.attr,
    &dev_attr_state.attr,
    &dev_attr_timeout.attr,
    &dev_attr_iocounterbits.attr,
    &dev_attr_iorequest_cnt.attr,
    &dev_attr_iodone_cnt.attr,
    &dev_attr_ioerr_cnt.attr,
    &dev_attr_modalias.attr,
    REF_EVT(media_change),
    NULL
};

static struct attribute_group scsi_sdev_attr_group = {
    .attrs =    scsi_sdev_attrs,
};

static const struct attribute_group *scsi_sdev_attr_groups[] = {
    &scsi_sdev_attr_group,
    NULL
};

static ssize_t
sdev_store_queue_depth_rw(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count)
{
    int depth, retval;
    struct scsi_device *sdev = to_scsi_device(dev);
    struct scsi_host_template *sht = sdev->host->hostt;

    if (!sht->change_queue_depth)
        return -EINVAL;

    depth = simple_strtoul(buf, NULL, 0);

    if (depth < 1)
        return -EINVAL;

    retval = sht->change_queue_depth(sdev, depth,
                     SCSI_QDEPTH_DEFAULT);
    if (retval < 0)
        return retval;

    sdev->max_queue_depth = sdev->queue_depth;

    return count;
}

static struct device_attribute sdev_attr_queue_depth_rw =
    __ATTR(queue_depth, S_IRUGO | S_IWUSR, sdev_show_queue_depth,
           sdev_store_queue_depth_rw);

static ssize_t
sdev_show_queue_ramp_up_period(struct device *dev,
                   struct device_attribute *attr,
                   char *buf)
{
    struct scsi_device *sdev;
    sdev = to_scsi_device(dev);
    return snprintf(buf, 20, "%u\n",
            jiffies_to_msecs(sdev->queue_ramp_up_period));
}

static ssize_t
sdev_store_queue_ramp_up_period(struct device *dev,
                struct device_attribute *attr,
                const char *buf, size_t count)
{
    struct scsi_device *sdev = to_scsi_device(dev);
    unsigned long period;

    if (strict_strtoul(buf, 10, &period))
        return -EINVAL;

    sdev->queue_ramp_up_period = msecs_to_jiffies(period);
    return period;
}

static struct device_attribute sdev_attr_queue_ramp_up_period =
    __ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR,
           sdev_show_queue_ramp_up_period,
           sdev_store_queue_ramp_up_period);

static ssize_t
sdev_store_queue_type_rw(struct device *dev, struct device_attribute *attr,
             const char *buf, size_t count)
{
    struct scsi_device *sdev = to_scsi_device(dev);
    struct scsi_host_template *sht = sdev->host->hostt;
    int tag_type = 0, retval;
    int prev_tag_type = scsi_get_tag_type(sdev);

    if (!sdev->tagged_supported || !sht->change_queue_type)
        return -EINVAL;

    if (strncmp(buf, "ordered", 7) == 0)
        tag_type = MSG_ORDERED_TAG;
    else if (strncmp(buf, "simple", 6) == 0)
        tag_type = MSG_SIMPLE_TAG;
    else if (strncmp(buf, "none", 4) != 0)
        return -EINVAL;

    if (tag_type == prev_tag_type)
        return count;

    retval = sht->change_queue_type(sdev, tag_type);
    if (retval < 0)
        return retval;

    return count;
}

static int scsi_target_add(struct scsi_target *starget)
{
    int error;

    if (starget->state != STARGET_CREATED)
        return 0;

    error = device_add(&starget->dev);
    if (error) {
        dev_err(&starget->dev, "target device_add failed, error %d\n", error);
        return error;
    }
    transport_add_device(&starget->dev);
    starget->state = STARGET_RUNNING;

    pm_runtime_set_active(&starget->dev);
    pm_runtime_enable(&starget->dev);
    device_enable_async_suspend(&starget->dev);

    return 0;
}

static struct device_attribute sdev_attr_queue_type_rw =
    __ATTR(queue_type, S_IRUGO | S_IWUSR, show_queue_type_field,
           sdev_store_queue_type_rw);

int scsi_sysfs_add_sdev(struct scsi_device *sdev)
{
    int error, i;
    struct request_queue *rq = sdev->request_queue;
    struct scsi_target *starget = sdev->sdev_target;

    error = scsi_device_set_state(sdev, SDEV_RUNNING);
    if (error)
        return error;

    error = scsi_target_add(starget);
    if (error)
        return error;

    transport_configure_device(&starget->dev);

    device_enable_async_suspend(&sdev->sdev_gendev);
    scsi_autopm_get_target(starget);
    pm_runtime_set_active(&sdev->sdev_gendev);
    pm_runtime_forbid(&sdev->sdev_gendev);
    pm_runtime_enable(&sdev->sdev_gendev);
    scsi_autopm_put_target(starget);

    /* The following call will keep sdev active indefinitely, until
     * its driver does a corresponding scsi_autopm_pm_device().  Only
     * drivers supporting autosuspend will do this.
     */
    scsi_autopm_get_device(sdev);

    error = device_add(&sdev->sdev_gendev);
    if (error) {
        sdev_printk(KERN_INFO, sdev,
                "failed to add device: %d\n", error);
        return error;
    }
    device_enable_async_suspend(&sdev->sdev_dev);
    error = device_add(&sdev->sdev_dev);
    if (error) {
        sdev_printk(KERN_INFO, sdev,
                "failed to add class device: %d\n", error);
        device_del(&sdev->sdev_gendev);
        return error;
    }
    transport_add_device(&sdev->sdev_gendev);
    sdev->is_visible = 1;

    /* create queue files, which may be writable, depending on the host */
    if (sdev->host->hostt->change_queue_depth) {
        error = device_create_file(&sdev->sdev_gendev,
                       &sdev_attr_queue_depth_rw);
        error = device_create_file(&sdev->sdev_gendev,
                       &sdev_attr_queue_ramp_up_period);
    }
    else
        error = device_create_file(&sdev->sdev_gendev, &dev_attr_queue_depth);
    if (error)
        return error;

    if (sdev->host->hostt->change_queue_type)
        error = device_create_file(&sdev->sdev_gendev, &sdev_attr_queue_type_rw);
    else
        error = device_create_file(&sdev->sdev_gendev, &dev_attr_queue_type);
    if (error)
        return error;

    error = bsg_register_queue(rq, &sdev->sdev_gendev, NULL, NULL);

    if (error)
        /* we're treating error on bsg register as non-fatal,
         * so pretend nothing went wrong */
        sdev_printk(KERN_INFO, sdev,
                "Failed to register bsg queue, errno=%d\n", error);

    /* add additional host specific attributes */
    if (sdev->host->hostt->sdev_attrs) {
        for (i = 0; sdev->host->hostt->sdev_attrs[i]; i++) {
            error = device_create_file(&sdev->sdev_gendev,
                    sdev->host->hostt->sdev_attrs[i]);
            if (error)
                return error;
        }
    }

    return error;
}

void __scsi_remove_device(struct scsi_device *sdev)
{
    struct device *dev = &sdev->sdev_gendev;

    if (sdev->is_visible) {
        if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
            return;

        bsg_unregister_queue(sdev->request_queue);
        device_unregister(&sdev->sdev_dev);
        transport_remove_device(dev);
        device_del(dev);
    } else
        put_device(&sdev->sdev_dev);

    /*
     * Stop accepting new requests and wait until all queuecommand() and
     * scsi_run_queue() invocations have finished before tearing down the
     * device.
     */
    scsi_device_set_state(sdev, SDEV_DEL);
    blk_cleanup_queue(sdev->request_queue);
    cancel_work_sync(&sdev->requeue_work);

    if (sdev->host->hostt->slave_destroy)
        sdev->host->hostt->slave_destroy(sdev);
    transport_destroy_device(dev);

    put_device(dev);
}

void scsi_remove_device(struct scsi_device *sdev)
{
    struct Scsi_Host *shost = sdev->host;

    mutex_lock(&shost->scan_mutex);
    __scsi_remove_device(sdev);
    mutex_unlock(&shost->scan_mutex);
}
EXPORT_SYMBOL(scsi_remove_device);

static void __scsi_remove_target(struct scsi_target *starget)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    unsigned long flags;
    struct scsi_device *sdev;

    spin_lock_irqsave(shost->host_lock, flags);
 restart:
    list_for_each_entry(sdev, &shost->__devices, siblings) {
        if (sdev->channel != starget->channel ||
            sdev->id != starget->id ||
            scsi_device_get(sdev))
            continue;
        spin_unlock_irqrestore(shost->host_lock, flags);
        scsi_remove_device(sdev);
        scsi_device_put(sdev);
        spin_lock_irqsave(shost->host_lock, flags);
        goto restart;
    }
    spin_unlock_irqrestore(shost->host_lock, flags);
}

void scsi_remove_target(struct device *dev)
{
    struct Scsi_Host *shost = dev_to_shost(dev->parent);
    struct scsi_target *starget, *last = NULL;
    unsigned long flags;

    /* remove targets being careful to lookup next entry before
     * deleting the last
     */
    spin_lock_irqsave(shost->host_lock, flags);
    list_for_each_entry(starget, &shost->__targets, siblings) {
        if (starget->state == STARGET_DEL)
            continue;
        if (starget->dev.parent == dev || &starget->dev == dev) {
            /* assuming new targets arrive at the end */
            starget->reap_ref++;
            spin_unlock_irqrestore(shost->host_lock, flags);
            if (last)
                scsi_target_reap(last);
            last = starget;
            __scsi_remove_target(starget);
            spin_lock_irqsave(shost->host_lock, flags);
        }
    }
    spin_unlock_irqrestore(shost->host_lock, flags);

    if (last)
        scsi_target_reap(last);
}
EXPORT_SYMBOL(scsi_remove_target);

int scsi_register_driver(struct device_driver *drv)
{
    drv->bus = &scsi_bus_type;

    return driver_register(drv);
}
EXPORT_SYMBOL(scsi_register_driver);

int scsi_register_interface(struct class_interface *intf)
{
    intf->class = &sdev_class;

    return class_interface_register(intf);
}
EXPORT_SYMBOL(scsi_register_interface);

int scsi_sysfs_add_host(struct Scsi_Host *shost)
{
    int error, i;

    /* add host specific attributes */
    if (shost->hostt->shost_attrs) {
        for (i = 0; shost->hostt->shost_attrs[i]; i++) {
            error = device_create_file(&shost->shost_dev,
                    shost->hostt->shost_attrs[i]);
            if (error)
                return error;
        }
    }

    transport_register_device(&shost->shost_gendev);
    transport_configure_device(&shost->shost_gendev);
    return 0;
}

static struct device_type scsi_dev_type = {
    .name =     "scsi_device",
    .release =  scsi_device_dev_release,
    .groups =   scsi_sdev_attr_groups,
};

void scsi_sysfs_device_initialize(struct scsi_device *sdev)
{
    unsigned long flags;
    struct Scsi_Host *shost = sdev->host;
    struct scsi_target  *starget = sdev->sdev_target;

    device_initialize(&sdev->sdev_gendev);
    sdev->sdev_gendev.bus = &scsi_bus_type;
    sdev->sdev_gendev.type = &scsi_dev_type;
    dev_set_name(&sdev->sdev_gendev, "%d:%d:%d:%d",
             sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);

    device_initialize(&sdev->sdev_dev);
    sdev->sdev_dev.parent = get_device(&sdev->sdev_gendev);
    sdev->sdev_dev.class = &sdev_class;
    dev_set_name(&sdev->sdev_dev, "%d:%d:%d:%d",
             sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
    sdev->scsi_level = starget->scsi_level;
    transport_setup_device(&sdev->sdev_gendev);
    spin_lock_irqsave(shost->host_lock, flags);
    list_add_tail(&sdev->same_target_siblings, &starget->devices);
    list_add_tail(&sdev->siblings, &shost->__devices);
    spin_unlock_irqrestore(shost->host_lock, flags);
}

int scsi_is_sdev_device(const struct device *dev)
{
    return dev->type == &scsi_dev_type;
}
EXPORT_SYMBOL(scsi_is_sdev_device);

/* A blank transport template that is used in drivers that don't
 * yet implement Transport Attributes */
struct scsi_transport_template blank_transport_template = { { { {NULL, }, }, }, };