[PATCH] fix semaphore handling in __unregister_chrdev_region

[linux/fpc-iii.git] / drivers / scsi / scsi_ioctl.c

/*
 * Changes:
 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
 * - get rid of some verify_areas and use __copy*user and __get/put_user
 *   for the ones that remain
 */
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <asm/uaccess.h>

#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_request.h>
#include <scsi/sg.h>
#include <scsi/scsi_dbg.h>

#include "scsi_logging.h"

#define NORMAL_RETRIES                  5
#define IOCTL_NORMAL_TIMEOUT                    (10 * HZ)

#define MAX_BUF PAGE_SIZE

/*
 * If we are told to probe a host, we will return 0 if  the host is not
 * present, 1 if the host is present, and will return an identifying
 * string at *arg, if arg is non null, filling to the length stored at
 * (int *) arg
 */

static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
{
        unsigned int len, slen;
        const char *string;
        int temp = host->hostt->present;

        if (temp && buffer) {
                if (get_user(len, (unsigned int __user *) buffer))
                        return -EFAULT;

                if (host->hostt->info)
                        string = host->hostt->info(host);
                else
                        string = host->hostt->name;
                if (string) {
                        slen = strlen(string);
                        if (len > slen)
                                len = slen + 1;
                        if (copy_to_user(buffer, string, len))
                                return -EFAULT;
                }
        }
        return temp;
}

/*

 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.  
 * 
 * dev is the SCSI device struct ptr, *(int *) arg is the length of the
 * input data, if any, not including the command string & counts, 
 * *((int *)arg + 1) is the output buffer size in bytes.
 * 
 * *(char *) ((int *) arg)[2] the actual command byte.   
 * 
 * Note that if more than MAX_BUF bytes are requested to be transferred,
 * the ioctl will fail with error EINVAL.
 * 
 * This size *does not* include the initial lengths that were passed.
 * 
 * The SCSI command is read from the memory location immediately after the
 * length words, and the input data is right after the command.  The SCSI
 * routines know the command size based on the opcode decode.  
 * 
 * The output area is then filled in starting from the command byte. 
 */

static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
                                  int timeout, int retries)
{
        struct scsi_request *sreq;
        int result;
        struct scsi_sense_hdr sshdr;

        SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd));

        sreq = scsi_allocate_request(sdev, GFP_KERNEL);
        if (!sreq) {
                printk(KERN_WARNING "SCSI internal ioctl failed, no memory\n");
                return -ENOMEM;
        }

        sreq->sr_data_direction = DMA_NONE;
        scsi_wait_req(sreq, cmd, NULL, 0, timeout, retries);

        SCSI_LOG_IOCTL(2, printk("Ioctl returned  0x%x\n", sreq->sr_result));

        if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
            (scsi_request_normalize_sense(sreq, &sshdr))) {
                switch (sshdr.sense_key) {
                case ILLEGAL_REQUEST:
                        if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
                                sdev->lockable = 0;
                        else
                                printk(KERN_INFO "ioctl_internal_command: "
                                       "ILLEGAL REQUEST asc=0x%x ascq=0x%x\n",
                                       sshdr.asc, sshdr.ascq);
                        break;
                case NOT_READY: /* This happens if there is no disc in drive */
                        if (sdev->removable && (cmd[0] != TEST_UNIT_READY)) {
                                printk(KERN_INFO "Device not ready. Make sure"
                                       " there is a disc in the drive.\n");
                                break;
                        }
                case UNIT_ATTENTION:
                        if (sdev->removable) {
                                sdev->changed = 1;
                                sreq->sr_result = 0;    /* This is no longer considered an error */
                                break;
                        }
                default:        /* Fall through for non-removable media */
                        printk(KERN_INFO "ioctl_internal_command: <%d %d %d "
                               "%d> return code = %x\n",
                               sdev->host->host_no,
                               sdev->channel,
                               sdev->id,
                               sdev->lun,
                               sreq->sr_result);
                        scsi_print_req_sense("   ", sreq);
                        break;
                }
        }

        result = sreq->sr_result;
        SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
        scsi_release_request(sreq);
        return result;
}

int scsi_set_medium_removal(struct scsi_device *sdev, char state)
{
        char scsi_cmd[MAX_COMMAND_SIZE];
        int ret;

        if (!sdev->removable || !sdev->lockable)
               return 0;

        scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
        scsi_cmd[1] = 0;
        scsi_cmd[2] = 0;
        scsi_cmd[3] = 0;
        scsi_cmd[4] = state;
        scsi_cmd[5] = 0;

        ret = ioctl_internal_command(sdev, scsi_cmd,
                        IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
        if (ret == 0)
                sdev->locked = (state == SCSI_REMOVAL_PREVENT);
        return ret;
}
EXPORT_SYMBOL(scsi_set_medium_removal);

/*
 * This interface is deprecated - users should use the scsi generic (sg)
 * interface instead, as this is a more flexible approach to performing
 * generic SCSI commands on a device.
 *
 * The structure that we are passed should look like:
 *
 * struct sdata {
 *  unsigned int inlen;      [i] Length of data to be written to device 
 *  unsigned int outlen;     [i] Length of data to be read from device 
 *  unsigned char cmd[x];    [i] SCSI command (6 <= x <= 12).
 *                           [o] Data read from device starts here.
 *                           [o] On error, sense buffer starts here.
 *  unsigned char wdata[y];  [i] Data written to device starts here.
 * };
 * Notes:
 *   -  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 (4K on i386, 8K on alpha).
 *   -  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.
 *      See the drivers/scsi/scsi.h file for more information on this.
 *
 */
#define OMAX_SB_LEN 16          /* Old sense buffer length */

int scsi_ioctl_send_command(struct scsi_device *sdev,
                            struct scsi_ioctl_command __user *sic)
{
        char *buf;
        unsigned char cmd[MAX_COMMAND_SIZE];
        char __user *cmd_in;
        struct scsi_request *sreq;
        unsigned char opcode;
        unsigned int inlen, outlen, cmdlen;
        unsigned int needed, buf_needed;
        int timeout, retries, result;
        int data_direction, gfp_mask = GFP_KERNEL;

        if (!sic)
                return -EINVAL;

        if (sdev->host->unchecked_isa_dma)
                gfp_mask |= GFP_DMA;

        /*
         * Verify that we can read at least this much.
         */
        if (!access_ok(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command)))
                return -EFAULT;

        if(__get_user(inlen, &sic->inlen))
                return -EFAULT;
                
        if(__get_user(outlen, &sic->outlen))
                return -EFAULT;

        /*
         * We do not transfer more than MAX_BUF with this interface.
         * If the user needs to transfer more data than this, they
         * should use scsi_generics (sg) instead.
         */
        if (inlen > MAX_BUF)
                return -EINVAL;
        if (outlen > MAX_BUF)
                return -EINVAL;

        cmd_in = sic->data;
        if(get_user(opcode, cmd_in))
                return -EFAULT;

        needed = buf_needed = (inlen > outlen ? inlen : outlen);
        if (buf_needed) {
                buf_needed = (buf_needed + 511) & ~511;
                if (buf_needed > MAX_BUF)
                        buf_needed = MAX_BUF;
                buf = kmalloc(buf_needed, gfp_mask);
                if (!buf)
                        return -ENOMEM;
                memset(buf, 0, buf_needed);
                if (inlen == 0) {
                        data_direction = DMA_FROM_DEVICE;
                } else if (outlen == 0 ) {
                        data_direction = DMA_TO_DEVICE;
                } else {
                        /*
                         * Can this ever happen?
                         */
                        data_direction = DMA_BIDIRECTIONAL;
                }

        } else {
                buf = NULL;
                data_direction = DMA_NONE;
        }

        /*
         * Obtain the command from the user's address space.
         */
        cmdlen = COMMAND_SIZE(opcode);
        
        result = -EFAULT;

        if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen))
                goto error;

        if(__copy_from_user(cmd, cmd_in, cmdlen))
                goto error;

        /*
         * Obtain the data to be sent to the device (if any).
         */

        if(copy_from_user(buf, cmd_in + cmdlen, inlen))
                goto error;

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

        sreq = scsi_allocate_request(sdev, GFP_KERNEL);
        if (!sreq) {
                result = -EINTR;
                goto error;
        }

        sreq->sr_data_direction = data_direction;
        scsi_wait_req(sreq, cmd, buf, needed, timeout, retries);

        /* 
         * If there was an error condition, pass the info back to the user. 
         */
        result = sreq->sr_result;
        if (result) {
                int sb_len = sizeof(sreq->sr_sense_buffer);

                sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len;
                if (copy_to_user(cmd_in, sreq->sr_sense_buffer, sb_len))
                        result = -EFAULT;
        } else {
                if (copy_to_user(cmd_in, buf, outlen))
                        result = -EFAULT;
        }       

        scsi_release_request(sreq);
error:
        kfree(buf);
        return result;
}
EXPORT_SYMBOL(scsi_ioctl_send_command);

/*
 * The scsi_ioctl_get_pci() function places into arg the value
 * pci_dev::slot_name (8 characters) for the PCI device (if any).
 * Returns: 0 on success
 *          -ENXIO if there isn't a PCI device pointer
 *                 (could be because the SCSI driver hasn't been
 *                  updated yet, or because it isn't a SCSI
 *                  device)
 *          any copy_to_user() error on failure there
 */
static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
{
        struct device *dev = scsi_get_device(sdev->host);

        if (!dev)
                return -ENXIO;
        return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0;
}


/*
 * the scsi_ioctl() function differs from most ioctls in that it does
 * not take a major/minor number as the dev field.  Rather, it takes
 * a pointer to a scsi_devices[] element, a structure. 
 */
int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
{
        char scsi_cmd[MAX_COMMAND_SIZE];

        /* No idea how this happens.... */
        if (!sdev)
                return -ENXIO;

        /*
         * If we are in the middle of error recovery, don't let anyone
         * else try and use this device.  Also, if error recovery fails, it
         * may try and take the device offline, in which case all further
         * access to the device is prohibited.
         */
        if (!scsi_block_when_processing_errors(sdev))
                return -ENODEV;

        /* Check for deprecated ioctls ... all the ioctls which don't
         * follow the new unique numbering scheme are deprecated */
        switch (cmd) {
        case SCSI_IOCTL_SEND_COMMAND:
        case SCSI_IOCTL_TEST_UNIT_READY:
        case SCSI_IOCTL_BENCHMARK_COMMAND:
        case SCSI_IOCTL_SYNC:
        case SCSI_IOCTL_START_UNIT:
        case SCSI_IOCTL_STOP_UNIT:
                printk(KERN_WARNING "program %s is using a deprecated SCSI "
                       "ioctl, please convert it to SG_IO\n", current->comm);
                break;
        default:
                break;
        }

        switch (cmd) {
        case SCSI_IOCTL_GET_IDLUN:
                if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
                        return -EFAULT;

                __put_user((sdev->id & 0xff)
                         + ((sdev->lun & 0xff) << 8)
                         + ((sdev->channel & 0xff) << 16)
                         + ((sdev->host->host_no & 0xff) << 24),
                         &((struct scsi_idlun __user *)arg)->dev_id);
                __put_user(sdev->host->unique_id,
                         &((struct scsi_idlun __user *)arg)->host_unique_id);
                return 0;
        case SCSI_IOCTL_GET_BUS_NUMBER:
                return put_user(sdev->host->host_no, (int __user *)arg);
        case SCSI_IOCTL_PROBE_HOST:
                return ioctl_probe(sdev->host, arg);
        case SCSI_IOCTL_SEND_COMMAND:
                if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
                        return -EACCES;
                return scsi_ioctl_send_command(sdev, arg);
        case SCSI_IOCTL_DOORLOCK:
                return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
        case SCSI_IOCTL_DOORUNLOCK:
                return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
        case SCSI_IOCTL_TEST_UNIT_READY:
                return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
                                            NORMAL_RETRIES);
        case SCSI_IOCTL_START_UNIT:
                scsi_cmd[0] = START_STOP;
                scsi_cmd[1] = 0;
                scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
                scsi_cmd[4] = 1;
                return ioctl_internal_command(sdev, scsi_cmd,
                                     START_STOP_TIMEOUT, NORMAL_RETRIES);
        case SCSI_IOCTL_STOP_UNIT:
                scsi_cmd[0] = START_STOP;
                scsi_cmd[1] = 0;
                scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
                scsi_cmd[4] = 0;
                return ioctl_internal_command(sdev, scsi_cmd,
                                     START_STOP_TIMEOUT, NORMAL_RETRIES);
        case SCSI_IOCTL_GET_PCI:
                return scsi_ioctl_get_pci(sdev, arg);
        default:
                if (sdev->host->hostt->ioctl)
                        return sdev->host->hostt->ioctl(sdev, cmd, arg);
        }
        return -EINVAL;
}
EXPORT_SYMBOL(scsi_ioctl);

/*
 * the scsi_nonblock_ioctl() function is designed for ioctls which may
 * be executed even if the device is in recovery.
 */
int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
                            void __user *arg, struct file *filp)
{
        int val, result;

        /* The first set of iocts may be executed even if we're doing
         * error processing, as long as the device was opened
         * non-blocking */
        if (filp && filp->f_flags & O_NONBLOCK) {
                if (test_bit(SHOST_RECOVERY,
                             &sdev->host->shost_state))
                        return -ENODEV;
        } else if (!scsi_block_when_processing_errors(sdev))
                return -ENODEV;

        switch (cmd) {
        case SG_SCSI_RESET:
                result = get_user(val, (int __user *)arg);
                if (result)
                        return result;
                if (val == SG_SCSI_RESET_NOTHING)
                        return 0;
                switch (val) {
                case SG_SCSI_RESET_DEVICE:
                        val = SCSI_TRY_RESET_DEVICE;
                        break;
                case SG_SCSI_RESET_BUS:
                        val = SCSI_TRY_RESET_BUS;
                        break;
                case SG_SCSI_RESET_HOST:
                        val = SCSI_TRY_RESET_HOST;
                        break;
                default:
                        return -EINVAL;
                }
                if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
                        return -EACCES;
                return (scsi_reset_provider(sdev, val) ==
                        SUCCESS) ? 0 : -EIO;
        }
        return -ENODEV;
}
EXPORT_SYMBOL(scsi_nonblockable_ioctl);