dasd_ioctl.c

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/*
 * Author(s)......: Holger Smolinski <[email protected]>
 *          Horst Hummel <[email protected]>
 *          Carsten Otte <[email protected]>
 *          Martin Schwidefsky <[email protected]>
 * Bugreports.to..: <[email protected]>
 * Copyright IBM Corp. 1999, 2001
 *
 * i/o controls for the dasd driver.
 */

#define KMSG_COMPONENT "dasd"

#include <linux/interrupt.h>
#include <linux/compat.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/blkpg.h>
#include <linux/slab.h>
#include <asm/compat.h>
#include <asm/ccwdev.h>
#include <asm/cmb.h>
#include <asm/uaccess.h>

/* This is ugly... */
#define PRINTK_HEADER "dasd_ioctl:"

#include "dasd_int.h"


static int
dasd_ioctl_api_version(void __user *argp)
{
    int ver = DASD_API_VERSION;
    return put_user(ver, (int __user *)argp);
}

/*
 * Enable device.
 * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
 */
static int
dasd_ioctl_enable(struct block_device *bdev)
{
    struct dasd_device *base;

    if (!capable(CAP_SYS_ADMIN))
        return -EACCES;

    base = dasd_device_from_gendisk(bdev->bd_disk);
    if (!base)
        return -ENODEV;

    dasd_enable_device(base);
    /* Formatting the dasd device can change the capacity. */
    mutex_lock(&bdev->bd_mutex);
    i_size_write(bdev->bd_inode,
             (loff_t)get_capacity(base->block->gdp) << 9);
    mutex_unlock(&bdev->bd_mutex);
    dasd_put_device(base);
    return 0;
}

/*
 * Disable device.
 * Used by dasdfmt. Disable I/O operations but allow ioctls.
 */
static int
dasd_ioctl_disable(struct block_device *bdev)
{
    struct dasd_device *base;

    if (!capable(CAP_SYS_ADMIN))
        return -EACCES;

    base = dasd_device_from_gendisk(bdev->bd_disk);
    if (!base)
        return -ENODEV;
    /*
     * Man this is sick. We don't do a real disable but only downgrade
     * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
     * BIODASDDISABLE to disable accesses to the device via the block
     * device layer but it still wants to do i/o on the device by
     * using the BIODASDFMT ioctl. Therefore the correct state for the
     * device is DASD_STATE_BASIC that allows to do basic i/o.
     */
    dasd_set_target_state(base, DASD_STATE_BASIC);
    /*
     * Set i_size to zero, since read, write, etc. check against this
     * value.
     */
    mutex_lock(&bdev->bd_mutex);
    i_size_write(bdev->bd_inode, 0);
    mutex_unlock(&bdev->bd_mutex);
    dasd_put_device(base);
    return 0;
}

/*
 * Quiesce device.
 */
static int dasd_ioctl_quiesce(struct dasd_block *block)
{
    unsigned long flags;
    struct dasd_device *base;

    base = block->base;
    if (!capable (CAP_SYS_ADMIN))
        return -EACCES;

    pr_info("%s: The DASD has been put in the quiesce "
        "state\n", dev_name(&base->cdev->dev));
    spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
    dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
    spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
    return 0;
}


/*
 * Resume device.
 */
static int dasd_ioctl_resume(struct dasd_block *block)
{
    unsigned long flags;
    struct dasd_device *base;

    base = block->base;
    if (!capable (CAP_SYS_ADMIN))
        return -EACCES;

    pr_info("%s: I/O operations have been resumed "
        "on the DASD\n", dev_name(&base->cdev->dev));
    spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
    dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
    spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);

    dasd_schedule_block_bh(block);
    return 0;
}

/*
 * performs formatting of _device_ according to _fdata_
 * Note: The discipline's format_function is assumed to deliver formatting
 * commands to format a single unit of the device. In terms of the ECKD
 * devices this means CCWs are generated to format a single track.
 */
static int dasd_format(struct dasd_block *block, struct format_data_t *fdata)
{
    struct dasd_ccw_req *cqr;
    struct dasd_device *base;
    int rc;

    base = block->base;
    if (base->discipline->format_device == NULL)
        return -EPERM;

    if (base->state != DASD_STATE_BASIC) {
        pr_warning("%s: The DASD cannot be formatted while it is "
               "enabled\n",  dev_name(&base->cdev->dev));
        return -EBUSY;
    }

    DBF_DEV_EVENT(DBF_NOTICE, base,
              "formatting units %u to %u (%u B blocks) flags %u",
              fdata->start_unit,
              fdata->stop_unit, fdata->blksize, fdata->intensity);

    /* Since dasdfmt keeps the device open after it was disabled,
     * there still exists an inode for this device.
     * We must update i_blkbits, otherwise we might get errors when
     * enabling the device later.
     */
    if (fdata->start_unit == 0) {
        struct block_device *bdev = bdget_disk(block->gdp, 0);
        bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
        bdput(bdev);
    }

    while (fdata->start_unit <= fdata->stop_unit) {
        cqr = base->discipline->format_device(base, fdata);
        if (IS_ERR(cqr))
            return PTR_ERR(cqr);
        rc = dasd_sleep_on_interruptible(cqr);
        dasd_sfree_request(cqr, cqr->memdev);
        if (rc) {
            if (rc != -ERESTARTSYS)
                pr_err("%s: Formatting unit %d failed with "
                       "rc=%d\n", dev_name(&base->cdev->dev),
                       fdata->start_unit, rc);
            return rc;
        }
        fdata->start_unit++;
    }
    return 0;
}

/*
 * Format device.
 */
static int
dasd_ioctl_format(struct block_device *bdev, void __user *argp)
{
    struct dasd_device *base;
    struct format_data_t fdata;
    int rc;

    if (!capable(CAP_SYS_ADMIN))
        return -EACCES;
    if (!argp)
        return -EINVAL;
    base = dasd_device_from_gendisk(bdev->bd_disk);
    if (!base)
        return -ENODEV;
    if (base->features & DASD_FEATURE_READONLY ||
        test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
        dasd_put_device(base);
        return -EROFS;
    }
    if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
        dasd_put_device(base);
        return -EFAULT;
    }
    if (bdev != bdev->bd_contains) {
        pr_warning("%s: The specified DASD is a partition and cannot "
               "be formatted\n",
               dev_name(&base->cdev->dev));
        dasd_put_device(base);
        return -EINVAL;
    }
    rc = dasd_format(base->block, &fdata);
    dasd_put_device(base);
    return rc;
}

#ifdef CONFIG_DASD_PROFILE
/*
 * Reset device profile information
 */
static int dasd_ioctl_reset_profile(struct dasd_block *block)
{
    dasd_profile_reset(&block->profile);
    return 0;
}

/*
 * Return device profile information
 */
static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
{
    struct dasd_profile_info_t *data;
    int rc = 0;

    data = kmalloc(sizeof(*data), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    spin_lock_bh(&block->profile.lock);
    if (block->profile.data) {
        data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
        data->dasd_io_sects = block->profile.data->dasd_io_sects;
        memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
               sizeof(data->dasd_io_secs));
        memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
               sizeof(data->dasd_io_times));
        memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
               sizeof(data->dasd_io_timps));
        memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
               sizeof(data->dasd_io_time1));
        memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
               sizeof(data->dasd_io_time2));
        memcpy(data->dasd_io_time2ps,
               block->profile.data->dasd_io_time2ps,
               sizeof(data->dasd_io_time2ps));
        memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
               sizeof(data->dasd_io_time3));
        memcpy(data->dasd_io_nr_req,
               block->profile.data->dasd_io_nr_req,
               sizeof(data->dasd_io_nr_req));
        spin_unlock_bh(&block->profile.lock);
    } else {
        spin_unlock_bh(&block->profile.lock);
        rc = -EIO;
        goto out;
    }
    if (copy_to_user(argp, data, sizeof(*data)))
        rc = -EFAULT;
out:
    kfree(data);
    return rc;
}
#else
static int dasd_ioctl_reset_profile(struct dasd_block *block)
{
    return -ENOTTY;
}

static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
{
    return -ENOTTY;
}
#endif

/*
 * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 */
static int dasd_ioctl_information(struct dasd_block *block,
                  unsigned int cmd, void __user *argp)
{
    struct dasd_information2_t *dasd_info;
    unsigned long flags;
    int rc;
    struct dasd_device *base;
    struct ccw_device *cdev;
    struct ccw_dev_id dev_id;

    base = block->base;
    if (!base->discipline || !base->discipline->fill_info)
        return -EINVAL;

    dasd_info = kzalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
    if (dasd_info == NULL)
        return -ENOMEM;

    rc = base->discipline->fill_info(base, dasd_info);
    if (rc) {
        kfree(dasd_info);
        return rc;
    }

    cdev = base->cdev;
    ccw_device_get_id(cdev, &dev_id);

    dasd_info->devno = dev_id.devno;
    dasd_info->schid = _ccw_device_get_subchannel_number(base->cdev);
    dasd_info->cu_type = cdev->id.cu_type;
    dasd_info->cu_model = cdev->id.cu_model;
    dasd_info->dev_type = cdev->id.dev_type;
    dasd_info->dev_model = cdev->id.dev_model;
    dasd_info->status = base->state;
    /*
     * The open_count is increased for every opener, that includes
     * the blkdev_get in dasd_scan_partitions.
     * This must be hidden from user-space.
     */
    dasd_info->open_count = atomic_read(&block->open_count);
    if (!block->bdev)
        dasd_info->open_count++;

    /*
     * check if device is really formatted
     * LDL / CDL was returned by 'fill_info'
     */
    if ((base->state < DASD_STATE_READY) ||
        (dasd_check_blocksize(block->bp_block)))
        dasd_info->format = DASD_FORMAT_NONE;

    dasd_info->features |=
        ((base->features & DASD_FEATURE_READONLY) != 0);

    memcpy(dasd_info->type, base->discipline->name, 4);

    if (block->request_queue->request_fn) {
        struct list_head *l;
#ifdef DASD_EXTENDED_PROFILING
        {
            struct list_head *l;
            spin_lock_irqsave(&block->lock, flags);
            list_for_each(l, &block->request_queue->queue_head)
                dasd_info->req_queue_len++;
            spin_unlock_irqrestore(&block->lock, flags);
        }
#endif              /* DASD_EXTENDED_PROFILING */
        spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
        list_for_each(l, &base->ccw_queue)
            dasd_info->chanq_len++;
        spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
                       flags);
    }

    rc = 0;
    if (copy_to_user(argp, dasd_info,
             ((cmd == (unsigned int) BIODASDINFO2) ?
              sizeof(struct dasd_information2_t) :
              sizeof(struct dasd_information_t))))
        rc = -EFAULT;
    kfree(dasd_info);
    return rc;
}

/*
 * Set read only
 */
static int
dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
{
    struct dasd_device *base;
    int intval, rc;

    if (!capable(CAP_SYS_ADMIN))
        return -EACCES;
    if (bdev != bdev->bd_contains)
        // ro setting is not allowed for partitions
        return -EINVAL;
    if (get_user(intval, (int __user *)argp))
        return -EFAULT;
    base = dasd_device_from_gendisk(bdev->bd_disk);
    if (!base)
        return -ENODEV;
    if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
        dasd_put_device(base);
        return -EROFS;
    }
    set_disk_ro(bdev->bd_disk, intval);
    rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
    dasd_put_device(base);
    return rc;
}

static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
                  struct cmbdata __user *argp)
{
    size_t size = _IOC_SIZE(cmd);
    struct cmbdata data;
    int ret;

    ret = cmf_readall(block->base->cdev, &data);
    if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
        return -EFAULT;
    return ret;
}

int dasd_ioctl(struct block_device *bdev, fmode_t mode,
           unsigned int cmd, unsigned long arg)
{
    struct dasd_block *block;
    struct dasd_device *base;
    void __user *argp;
    int rc;

    if (is_compat_task())
        argp = compat_ptr(arg);
    else
        argp = (void __user *)arg;

    if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
        PRINT_DEBUG("empty data ptr");
        return -EINVAL;
    }

    base = dasd_device_from_gendisk(bdev->bd_disk);
    if (!base)
        return -ENODEV;
    block = base->block;
    rc = 0;
    switch (cmd) {
    case BIODASDDISABLE:
        rc = dasd_ioctl_disable(bdev);
        break;
    case BIODASDENABLE:
        rc = dasd_ioctl_enable(bdev);
        break;
    case BIODASDQUIESCE:
        rc = dasd_ioctl_quiesce(block);
        break;
    case BIODASDRESUME:
        rc = dasd_ioctl_resume(block);
        break;
    case BIODASDFMT:
        rc = dasd_ioctl_format(bdev, argp);
        break;
    case BIODASDINFO:
        rc = dasd_ioctl_information(block, cmd, argp);
        break;
    case BIODASDINFO2:
        rc = dasd_ioctl_information(block, cmd, argp);
        break;
    case BIODASDPRRD:
        rc = dasd_ioctl_read_profile(block, argp);
        break;
    case BIODASDPRRST:
        rc = dasd_ioctl_reset_profile(block);
        break;
    case BLKROSET:
        rc = dasd_ioctl_set_ro(bdev, argp);
        break;
    case DASDAPIVER:
        rc = dasd_ioctl_api_version(argp);
        break;
    case BIODASDCMFENABLE:
        rc = enable_cmf(base->cdev);
        break;
    case BIODASDCMFDISABLE:
        rc = disable_cmf(base->cdev);
        break;
    case BIODASDREADALLCMB:
        rc = dasd_ioctl_readall_cmb(block, cmd, argp);
        break;
    default:
        /* if the discipline has an ioctl method try it. */
        rc = -ENOTTY;
        if (base->discipline->ioctl)
            rc = base->discipline->ioctl(block, cmd, argp);
    }
    dasd_put_device(base);
    return rc;
}