/*
 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public Licens
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
 *
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/completion.h>
#include <linux/cdrom.h>
#include <linux/ratelimit.h>
#include <linux/slab.h>
#include <linux/times.h>
#include <linux/uio.h>
#include <asm/uaccess.h>

#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>

struct blk_cmd_filter {
        unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
        unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
};

static struct blk_cmd_filter blk_default_cmd_filter;

/* Command group 3 is reserved and should never be used.  */
const unsigned char scsi_command_size_tbl[8] =
{
        6, 10, 10, 12,
        16, 12, 10, 10
};
EXPORT_SYMBOL(scsi_command_size_tbl);

#include <scsi/sg.h>

static int sg_get_version(int __user *p)
{
        static const int sg_version_num = 30527;
        return put_user(sg_version_num, p);
}

static int scsi_get_idlun(struct request_queue *q, int __user *p)
{
        return put_user(0, p);
}

static int scsi_get_bus(struct request_queue *q, int __user *p)
{
        return put_user(0, p);
}

static int sg_get_timeout(struct request_queue *q)
{
        return jiffies_to_clock_t(q->sg_timeout);
}

static int sg_set_timeout(struct request_queue *q, int __user *p)
{
        int timeout, err = get_user(timeout, p);

        if (!err)
                q->sg_timeout = clock_t_to_jiffies(timeout);

        return err;
}

static int max_sectors_bytes(struct request_queue *q)
{
        unsigned int max_sectors = queue_max_sectors(q);

        max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);

        return max_sectors << 9;
}

static int sg_get_reserved_size(struct request_queue *q, int __user *p)
{
        int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));

        return put_user(val, p);
}

static int sg_set_reserved_size(struct request_queue *q, int __user *p)
{
        int size, err = get_user(size, p);

        if (err)
                return err;

        if (size < 0)
                return -EINVAL;

        q->sg_reserved_size = min(size, max_sectors_bytes(q));
        return 0;
}

/*
 * will always return that we are ATAPI even for a real SCSI drive, I'm not
 * so sure this is worth doing anything about (why would you care??)
 */
static int sg_emulated_host(struct request_queue *q, int __user *p)
{
        return put_user(1, p);
}

static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
{
        /* Basic read-only commands */
        __set_bit(TEST_UNIT_READY, filter->read_ok);
        __set_bit(REQUEST_SENSE, filter->read_ok);
        __set_bit(READ_6, filter->read_ok);
        __set_bit(READ_10, filter->read_ok);
        __set_bit(READ_12, filter->read_ok);
        __set_bit(READ_16, filter->read_ok);
        __set_bit(READ_BUFFER, filter->read_ok);
        __set_bit(READ_DEFECT_DATA, filter->read_ok);
        __set_bit(READ_CAPACITY, filter->read_ok);
        __set_bit(READ_LONG, filter->read_ok);
        __set_bit(INQUIRY, filter->read_ok);
        __set_bit(MODE_SENSE, filter->read_ok);
        __set_bit(MODE_SENSE_10, filter->read_ok);
        __set_bit(LOG_SENSE, filter->read_ok);
        __set_bit(START_STOP, filter->read_ok);
        __set_bit(GPCMD_VERIFY_10, filter->read_ok);
        __set_bit(VERIFY_16, filter->read_ok);
        __set_bit(REPORT_LUNS, filter->read_ok);
        __set_bit(SERVICE_ACTION_IN_16, filter->read_ok);
        __set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok);
        __set_bit(MAINTENANCE_IN, filter->read_ok);
        __set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok);

        /* Audio CD commands */
        __set_bit(GPCMD_PLAY_CD, filter->read_ok);
        __set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok);
        __set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok);
        __set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok);
        __set_bit(GPCMD_PAUSE_RESUME, filter->read_ok);

        /* CD/DVD data reading */
        __set_bit(GPCMD_READ_CD, filter->read_ok);
        __set_bit(GPCMD_READ_CD_MSF, filter->read_ok);
        __set_bit(GPCMD_READ_DISC_INFO, filter->read_ok);
        __set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok);
        __set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok);
        __set_bit(GPCMD_READ_HEADER, filter->read_ok);
        __set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok);
        __set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok);
        __set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok);
        __set_bit(GPCMD_REPORT_KEY, filter->read_ok);
        __set_bit(GPCMD_SCAN, filter->read_ok);
        __set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok);
        __set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok);
        __set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok);
        __set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok);
        __set_bit(GPCMD_SEEK, filter->read_ok);
        __set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok);

        /* Basic writing commands */
        __set_bit(WRITE_6, filter->write_ok);
        __set_bit(WRITE_10, filter->write_ok);
        __set_bit(WRITE_VERIFY, filter->write_ok);
        __set_bit(WRITE_12, filter->write_ok);
        __set_bit(WRITE_VERIFY_12, filter->write_ok);
        __set_bit(WRITE_16, filter->write_ok);
        __set_bit(WRITE_LONG, filter->write_ok);
        __set_bit(WRITE_LONG_2, filter->write_ok);
        __set_bit(ERASE, filter->write_ok);
        __set_bit(GPCMD_MODE_SELECT_10, filter->write_ok);
        __set_bit(MODE_SELECT, filter->write_ok);
        __set_bit(LOG_SELECT, filter->write_ok);
        __set_bit(GPCMD_BLANK, filter->write_ok);
        __set_bit(GPCMD_CLOSE_TRACK, filter->write_ok);
        __set_bit(GPCMD_FLUSH_CACHE, filter->write_ok);
        __set_bit(GPCMD_FORMAT_UNIT, filter->write_ok);
        __set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok);
        __set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok);
        __set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok);
        __set_bit(GPCMD_SEND_EVENT, filter->write_ok);
        __set_bit(GPCMD_SEND_KEY, filter->write_ok);
        __set_bit(GPCMD_SEND_OPC, filter->write_ok);
        __set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok);
        __set_bit(GPCMD_SET_SPEED, filter->write_ok);
        __set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
        __set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
        __set_bit(GPCMD_SET_STREAMING, filter->write_ok);
        __set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
}

int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
{
        struct blk_cmd_filter *filter = &blk_default_cmd_filter;

        /* root can do any command. */
        if (capable(CAP_SYS_RAWIO))
                return 0;

        /* Anybody who can open the device can do a read-safe command */
        if (test_bit(cmd[0], filter->read_ok))
                return 0;

        /* Write-safe commands require a writable open */
        if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
                return 0;

        return -EPERM;
}
EXPORT_SYMBOL(blk_verify_command);

static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
                             struct sg_io_hdr *hdr, fmode_t mode)
{
        if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
                return -EFAULT;
        if (blk_verify_command(rq->cmd, mode & FMODE_WRITE))
                return -EPERM;

        /*
         * fill in request structure
         */
        rq->cmd_len = hdr->cmd_len;

        rq->timeout = msecs_to_jiffies(hdr->timeout);
        if (!rq->timeout)
                rq->timeout = q->sg_timeout;
        if (!rq->timeout)
                rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
        if (rq->timeout < BLK_MIN_SG_TIMEOUT)
                rq->timeout = BLK_MIN_SG_TIMEOUT;

        return 0;
}

static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
                                 struct bio *bio)
{
        int r, ret = 0;

        /*
         * fill in all the output members
         */
        hdr->status = rq->errors & 0xff;
        hdr->masked_status = status_byte(rq->errors);
        hdr->msg_status = msg_byte(rq->errors);
        hdr->host_status = host_byte(rq->errors);
        hdr->driver_status = driver_byte(rq->errors);
        hdr->info = 0;
        if (hdr->masked_status || hdr->host_status || hdr->driver_status)
                hdr->info |= SG_INFO_CHECK;
        hdr->resid = rq->resid_len;
        hdr->sb_len_wr = 0;

        if (rq->sense_len && hdr->sbp) {
                int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);

                if (!copy_to_user(hdr->sbp, rq->sense, len))
                        hdr->sb_len_wr = len;
                else
                        ret = -EFAULT;
        }

        r = blk_rq_unmap_user(bio);
        if (!ret)
                ret = r;

        return ret;
}

static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
                struct sg_io_hdr *hdr, fmode_t mode)
{
        unsigned long start_time;
        ssize_t ret = 0;
        int writing = 0;
        int at_head = 0;
        struct request *rq;
        char sense[SCSI_SENSE_BUFFERSIZE];
        struct bio *bio;

        if (hdr->interface_id != 'S')
                return -EINVAL;

        if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
                return -EIO;

        if (hdr->dxfer_len)
                switch (hdr->dxfer_direction) {
                default:
                        return -EINVAL;
                case SG_DXFER_TO_DEV:
                        writing = 1;
                        break;
                case SG_DXFER_TO_FROM_DEV:
                case SG_DXFER_FROM_DEV:
                        break;
                }
        if (hdr->flags & SG_FLAG_Q_AT_HEAD)
                at_head = 1;

        ret = -ENOMEM;
        rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
        if (IS_ERR(rq))
                return PTR_ERR(rq);
        blk_rq_set_block_pc(rq);

        if (hdr->cmd_len > BLK_MAX_CDB) {
                rq->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
                if (!rq->cmd)
                        goto out_put_request;
        }

        ret = blk_fill_sghdr_rq(q, rq, hdr, mode);
        if (ret < 0)
                goto out_free_cdb;

        ret = 0;
        if (hdr->iovec_count) {
                struct iov_iter i;
                struct iovec *iov = NULL;

                ret = import_iovec(rq_data_dir(rq),
                                   hdr->dxferp, hdr->iovec_count,
                                   0, &iov, &i);
                if (ret < 0)
                        goto out_free_cdb;

                /* SG_IO howto says that the shorter of the two wins */
                iov_iter_truncate(&i, hdr->dxfer_len);

                ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
                kfree(iov);
        } else if (hdr->dxfer_len)
                ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
                                      GFP_KERNEL);

        if (ret)
                goto out_free_cdb;

        bio = rq->bio;
        memset(sense, 0, sizeof(sense));
        rq->sense = sense;
        rq->sense_len = 0;
        rq->retries = 0;

        start_time = jiffies;

        /* ignore return value. All information is passed back to caller
         * (if he doesn't check that is his problem).
         * N.B. a non-zero SCSI status is _not_ necessarily an error.
         */
        blk_execute_rq(q, bd_disk, rq, at_head);

        hdr->duration = jiffies_to_msecs(jiffies - start_time);

        ret = blk_complete_sghdr_rq(rq, hdr, bio);

out_free_cdb:
        if (rq->cmd != rq->__cmd)
                kfree(rq->cmd);
out_put_request:
        blk_put_request(rq);
        return ret;
}

/**
 * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
 * @file:       file this ioctl operates on (optional)
 * @q:          request queue to send scsi commands down
 * @disk:       gendisk to operate on (option)
 * @sic:        userspace structure describing the command to perform
 *
 * Send down the scsi command described by @sic to the device below
 * the request queue @q.  If @file is non-NULL it's used to perform
 * fine-grained permission checks that allow users to send down
 * non-destructive SCSI commands.  If the caller has a struct gendisk
 * available it should be passed in as @disk to allow the low level
 * driver to use the information contained in it.  A non-NULL @disk
 * is only allowed if the caller knows that the low level driver doesn't
 * need it (e.g. in the scsi subsystem).
 *
 * Notes:
 *   -  This interface is deprecated - users should use the SG_IO
 *      interface instead, as this is a more flexible approach to
 *      performing SCSI commands on a device.
 *   -  The SCSI command length is determined by examining the 1st byte
 *      of the given command. There is no way to override this.
 *   -  Data transfers are limited to PAGE_SIZE
 *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 *      accommodate the sense buffer when an error occurs.
 *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 *      old code will not be surprised.
 *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 *      a negative return and the Unix error code in 'errno'.
 *      If the SCSI command succeeds then 0 is returned.
 *      Positive numbers returned are the compacted SCSI error codes (4
 *      bytes in one int) where the lowest byte is the SCSI status.
 */
#define OMAX_SB_LEN 16          /* For backward compatibility */
int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
                struct scsi_ioctl_command __user *sic)
{
        struct request *rq;
        int err;
        unsigned int in_len, out_len, bytes, opcode, cmdlen;
        char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];

        if (!sic)
                return -EINVAL;

        /*
         * get in an out lengths, verify they don't exceed a page worth of data
         */
        if (get_user(in_len, &sic->inlen))
                return -EFAULT;
        if (get_user(out_len, &sic->outlen))
                return -EFAULT;
        if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
                return -EINVAL;
        if (get_user(opcode, sic->data))
                return -EFAULT;

        bytes = max(in_len, out_len);
        if (bytes) {
                buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
                if (!buffer)
                        return -ENOMEM;

        }

        rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_RECLAIM);
        if (IS_ERR(rq)) {
                err = PTR_ERR(rq);
                goto error_free_buffer;
        }
        blk_rq_set_block_pc(rq);

        cmdlen = COMMAND_SIZE(opcode);

        /*
         * get command and data to send to device, if any
         */
        err = -EFAULT;
        rq->cmd_len = cmdlen;
        if (copy_from_user(rq->cmd, sic->data, cmdlen))
                goto error;

        if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
                goto error;

        err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
        if (err)
                goto error;

        /* default.  possible overriden later */
        rq->retries = 5;

        switch (opcode) {
        case SEND_DIAGNOSTIC:
        case FORMAT_UNIT:
                rq->timeout = FORMAT_UNIT_TIMEOUT;
                rq->retries = 1;
                break;
        case START_STOP:
                rq->timeout = START_STOP_TIMEOUT;
                break;
        case MOVE_MEDIUM:
                rq->timeout = MOVE_MEDIUM_TIMEOUT;
                break;
        case READ_ELEMENT_STATUS:
                rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
                break;
        case READ_DEFECT_DATA:
                rq->timeout = READ_DEFECT_DATA_TIMEOUT;
                rq->retries = 1;
                break;
        default:
                rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
                break;
        }

        if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_RECLAIM)) {
                err = DRIVER_ERROR << 24;
                goto error;
        }

        memset(sense, 0, sizeof(sense));
        rq->sense = sense;
        rq->sense_len = 0;

        blk_execute_rq(q, disk, rq, 0);

        err = rq->errors & 0xff;        /* only 8 bit SCSI status */
        if (err) {
                if (rq->sense_len && rq->sense) {
                        bytes = (OMAX_SB_LEN > rq->sense_len) ?
                                rq->sense_len : OMAX_SB_LEN;
                        if (copy_to_user(sic->data, rq->sense, bytes))
                                err = -EFAULT;
                }
        } else {
                if (copy_to_user(sic->data, buffer, out_len))
                        err = -EFAULT;
        }
        
error:
        blk_put_request(rq);

error_free_buffer:
        kfree(buffer);

        return err;
}
EXPORT_SYMBOL_GPL(sg_scsi_ioctl);

/* Send basic block requests */
static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
                              int cmd, int data)
{
        struct request *rq;
        int err;

        rq = blk_get_request(q, WRITE, __GFP_RECLAIM);
        if (IS_ERR(rq))
                return PTR_ERR(rq);
        blk_rq_set_block_pc(rq);
        rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
        rq->cmd[0] = cmd;
        rq->cmd[4] = data;
        rq->cmd_len = 6;
        err = blk_execute_rq(q, bd_disk, rq, 0);
        blk_put_request(rq);

        return err;
}

static inline int blk_send_start_stop(struct request_queue *q,
                                      struct gendisk *bd_disk, int data)
{
        return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
}

int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
                   unsigned int cmd, void __user *arg)
{
        int err;

        if (!q)
                return -ENXIO;

        switch (cmd) {
                /*
                 * new sgv3 interface
                 */
                case SG_GET_VERSION_NUM:
                        err = sg_get_version(arg);
                        break;
                case SCSI_IOCTL_GET_IDLUN:
                        err = scsi_get_idlun(q, arg);
                        break;
                case SCSI_IOCTL_GET_BUS_NUMBER:
                        err = scsi_get_bus(q, arg);
                        break;
                case SG_SET_TIMEOUT:
                        err = sg_set_timeout(q, arg);
                        break;
                case SG_GET_TIMEOUT:
                        err = sg_get_timeout(q);
                        break;
                case SG_GET_RESERVED_SIZE:
                        err = sg_get_reserved_size(q, arg);
                        break;
                case SG_SET_RESERVED_SIZE:
                        err = sg_set_reserved_size(q, arg);
                        break;
                case SG_EMULATED_HOST:
                        err = sg_emulated_host(q, arg);
                        break;
                case SG_IO: {
                        struct sg_io_hdr hdr;

                        err = -EFAULT;
                        if (copy_from_user(&hdr, arg, sizeof(hdr)))
                                break;
                        err = sg_io(q, bd_disk, &hdr, mode);
                        if (err == -EFAULT)
                                break;

                        if (copy_to_user(arg, &hdr, sizeof(hdr)))
                                err = -EFAULT;
                        break;
                }
                case CDROM_SEND_PACKET: {
                        struct cdrom_generic_command cgc;
                        struct sg_io_hdr hdr;

                        err = -EFAULT;
                        if (copy_from_user(&cgc, arg, sizeof(cgc)))
                                break;
                        cgc.timeout = clock_t_to_jiffies(cgc.timeout);
                        memset(&hdr, 0, sizeof(hdr));
                        hdr.interface_id = 'S';
                        hdr.cmd_len = sizeof(cgc.cmd);
                        hdr.dxfer_len = cgc.buflen;
                        err = 0;
                        switch (cgc.data_direction) {
                                case CGC_DATA_UNKNOWN:
                                        hdr.dxfer_direction = SG_DXFER_UNKNOWN;
                                        break;
                                case CGC_DATA_WRITE:
                                        hdr.dxfer_direction = SG_DXFER_TO_DEV;
                                        break;
                                case CGC_DATA_READ:
                                        hdr.dxfer_direction = SG_DXFER_FROM_DEV;
                                        break;
                                case CGC_DATA_NONE:
                                        hdr.dxfer_direction = SG_DXFER_NONE;
                                        break;
                                default:
                                        err = -EINVAL;
                        }
                        if (err)
                                break;

                        hdr.dxferp = cgc.buffer;
                        hdr.sbp = cgc.sense;
                        if (hdr.sbp)
                                hdr.mx_sb_len = sizeof(struct request_sense);
                        hdr.timeout = jiffies_to_msecs(cgc.timeout);
                        hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
                        hdr.cmd_len = sizeof(cgc.cmd);

                        err = sg_io(q, bd_disk, &hdr, mode);
                        if (err == -EFAULT)
                                break;

                        if (hdr.status)
                                err = -EIO;

                        cgc.stat = err;
                        cgc.buflen = hdr.resid;
                        if (copy_to_user(arg, &cgc, sizeof(cgc)))
                                err = -EFAULT;

                        break;
                }

                /*
                 * old junk scsi send command ioctl
                 */
                case SCSI_IOCTL_SEND_COMMAND:
                        printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
                        err = -EINVAL;
                        if (!arg)
                                break;

                        err = sg_scsi_ioctl(q, bd_disk, mode, arg);
                        break;
                case CDROMCLOSETRAY:
                        err = blk_send_start_stop(q, bd_disk, 0x03);
                        break;
                case CDROMEJECT:
                        err = blk_send_start_stop(q, bd_disk, 0x02);
                        break;
                default:
                        err = -ENOTTY;
        }

        return err;
}
EXPORT_SYMBOL(scsi_cmd_ioctl);

int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
{
        if (bd && bd == bd->bd_contains)
                return 0;

        /* Actually none of these is particularly useful on a partition,
         * but they are safe.
         */
        switch (cmd) {
        case SCSI_IOCTL_GET_IDLUN:
        case SCSI_IOCTL_GET_BUS_NUMBER:
        case SCSI_IOCTL_GET_PCI:
        case SCSI_IOCTL_PROBE_HOST:
        case SG_GET_VERSION_NUM:
        case SG_SET_TIMEOUT:
        case SG_GET_TIMEOUT:
        case SG_GET_RESERVED_SIZE:
        case SG_SET_RESERVED_SIZE:
        case SG_EMULATED_HOST:
                return 0;
        case CDROM_GET_CAPABILITY:
                /* Keep this until we remove the printk below.  udev sends it
                 * and we do not want to spam dmesg about it.   CD-ROMs do
                 * not have partitions, so we get here only for disks.
                 */
                return -ENOIOCTLCMD;
        default:
                break;
        }

        if (capable(CAP_SYS_RAWIO))
                return 0;

        /* In particular, rule out all resets and host-specific ioctls.  */
        printk_ratelimited(KERN_WARNING
                           "%s: sending ioctl %x to a partition!\n", current->comm, cmd);

        return -ENOIOCTLCMD;
}
EXPORT_SYMBOL(scsi_verify_blk_ioctl);

int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
                       unsigned int cmd, void __user *arg)
{
        int ret;

        ret = scsi_verify_blk_ioctl(bd, cmd);
        if (ret < 0)
                return ret;

        return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
}
EXPORT_SYMBOL(scsi_cmd_blk_ioctl);

static int __init blk_scsi_ioctl_init(void)
{
        blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
        return 0;
}
fs_initcall(blk_scsi_ioctl_init);