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linux/block/scsi_ioctl.c
Christoph Hellwig 21b2f0c803 [SCSI] unify SCSI_IOCTL_SEND_COMMAND implementations 
We currently have two implementations of this obsolete ioctl, one in
the block layer and one in the scsi code.  Both of them have drawbacks.

This patch kills the scsi layer version after updating the block version
with the missing bits:

 - argument checking
 - use scatterlist I/O
 - set number of retries based on the submitted command

This is the last user of non-S/G I/O except for the gdth driver, so
getting this in ASAP and through the scsi tree would be nie to kill
the non-S/G I/O path.  Jens, what do you think about adding a check
for non-S/G I/O in the midlayer?

Thanks to  Or Gerlitz for testing this patch.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-04-13 10:13:15 -05:00

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/*
* 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/slab.h>
#include <linux/times.h>
#include <asm/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>
/* Command group 3 is reserved and should never be used. */
const unsigned char scsi_command_size[8] =
{
6, 10, 10, 12,
16, 12, 10, 10
};
EXPORT_SYMBOL(scsi_command_size);
#define BLK_DEFAULT_TIMEOUT (60 * HZ)
#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(request_queue_t *q, int __user *p)
{
return put_user(0, p);
}
static int scsi_get_bus(request_queue_t *q, int __user *p)
{
return put_user(0, p);
}
static int sg_get_timeout(request_queue_t *q)
{
return q->sg_timeout / (HZ / USER_HZ);
}
static int sg_set_timeout(request_queue_t *q, int __user *p)
{
int timeout, err = get_user(timeout, p);
if (!err)
q->sg_timeout = timeout * (HZ / USER_HZ);
return err;
}
static int sg_get_reserved_size(request_queue_t *q, int __user *p)
{
return put_user(q->sg_reserved_size, p);
}
static int sg_set_reserved_size(request_queue_t *q, int __user *p)
{
int size, err = get_user(size, p);
if (err)
return err;
if (size < 0)
return -EINVAL;
if (size > (q->max_sectors << 9))
size = q->max_sectors << 9;
q->sg_reserved_size = size;
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(request_queue_t *q, int __user *p)
{
return put_user(1, p);
}
#define CMD_READ_SAFE 0x01
#define CMD_WRITE_SAFE 0x02
#define CMD_WARNED 0x04
#define safe_for_read(cmd) [cmd] = CMD_READ_SAFE
#define safe_for_write(cmd) [cmd] = CMD_WRITE_SAFE
static int verify_command(struct file *file, unsigned char *cmd)
{
static unsigned char cmd_type[256] = {
/* Basic read-only commands */
safe_for_read(TEST_UNIT_READY),
safe_for_read(REQUEST_SENSE),
safe_for_read(READ_6),
safe_for_read(READ_10),
safe_for_read(READ_12),
safe_for_read(READ_16),
safe_for_read(READ_BUFFER),
safe_for_read(READ_DEFECT_DATA),
safe_for_read(READ_LONG),
safe_for_read(INQUIRY),
safe_for_read(MODE_SENSE),
safe_for_read(MODE_SENSE_10),
safe_for_read(LOG_SENSE),
safe_for_read(START_STOP),
safe_for_read(GPCMD_VERIFY_10),
safe_for_read(VERIFY_16),
/* Audio CD commands */
safe_for_read(GPCMD_PLAY_CD),
safe_for_read(GPCMD_PLAY_AUDIO_10),
safe_for_read(GPCMD_PLAY_AUDIO_MSF),
safe_for_read(GPCMD_PLAY_AUDIO_TI),
safe_for_read(GPCMD_PAUSE_RESUME),
/* CD/DVD data reading */
safe_for_read(GPCMD_READ_BUFFER_CAPACITY),
safe_for_read(GPCMD_READ_CD),
safe_for_read(GPCMD_READ_CD_MSF),
safe_for_read(GPCMD_READ_DISC_INFO),
safe_for_read(GPCMD_READ_CDVD_CAPACITY),
safe_for_read(GPCMD_READ_DVD_STRUCTURE),
safe_for_read(GPCMD_READ_HEADER),
safe_for_read(GPCMD_READ_TRACK_RZONE_INFO),
safe_for_read(GPCMD_READ_SUBCHANNEL),
safe_for_read(GPCMD_READ_TOC_PMA_ATIP),
safe_for_read(GPCMD_REPORT_KEY),
safe_for_read(GPCMD_SCAN),
safe_for_read(GPCMD_GET_CONFIGURATION),
safe_for_read(GPCMD_READ_FORMAT_CAPACITIES),
safe_for_read(GPCMD_GET_EVENT_STATUS_NOTIFICATION),
safe_for_read(GPCMD_GET_PERFORMANCE),
safe_for_read(GPCMD_SEEK),
safe_for_read(GPCMD_STOP_PLAY_SCAN),
/* Basic writing commands */
safe_for_write(WRITE_6),
safe_for_write(WRITE_10),
safe_for_write(WRITE_VERIFY),
safe_for_write(WRITE_12),
safe_for_write(WRITE_VERIFY_12),
safe_for_write(WRITE_16),
safe_for_write(WRITE_LONG),
safe_for_write(WRITE_LONG_2),
safe_for_write(ERASE),
safe_for_write(GPCMD_MODE_SELECT_10),
safe_for_write(MODE_SELECT),
safe_for_write(LOG_SELECT),
safe_for_write(GPCMD_BLANK),
safe_for_write(GPCMD_CLOSE_TRACK),
safe_for_write(GPCMD_FLUSH_CACHE),
safe_for_write(GPCMD_FORMAT_UNIT),
safe_for_write(GPCMD_REPAIR_RZONE_TRACK),
safe_for_write(GPCMD_RESERVE_RZONE_TRACK),
safe_for_write(GPCMD_SEND_DVD_STRUCTURE),
safe_for_write(GPCMD_SEND_EVENT),
safe_for_write(GPCMD_SEND_KEY),
safe_for_write(GPCMD_SEND_OPC),
safe_for_write(GPCMD_SEND_CUE_SHEET),
safe_for_write(GPCMD_SET_SPEED),
safe_for_write(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL),
safe_for_write(GPCMD_LOAD_UNLOAD),
safe_for_write(GPCMD_SET_STREAMING),
};
unsigned char type = cmd_type[cmd[0]];
int has_write_perm = 0;
/* Anybody who can open the device can do a read-safe command */
if (type & CMD_READ_SAFE)
return 0;
/*
* file can be NULL from ioctl_by_bdev()...
*/
if (file)
has_write_perm = file->f_mode & FMODE_WRITE;
/* Write-safe commands just require a writable open.. */
if ((type & CMD_WRITE_SAFE) && has_write_perm)
return 0;
/* And root can do any command.. */
if (capable(CAP_SYS_RAWIO))
return 0;
if (!type) {
cmd_type[cmd[0]] = CMD_WARNED;
printk(KERN_WARNING "scsi: unknown opcode 0x%02x\n", cmd[0]);
}
/* Otherwise fail it with an "Operation not permitted" */
return -EPERM;
}
static int sg_io(struct file *file, request_queue_t *q,
struct gendisk *bd_disk, struct sg_io_hdr *hdr)
{
unsigned long start_time;
int writing = 0, ret = 0;
struct request *rq;
struct bio *bio;
char sense[SCSI_SENSE_BUFFERSIZE];
unsigned char cmd[BLK_MAX_CDB];
if (hdr->interface_id != 'S')
return -EINVAL;
if (hdr->cmd_len > BLK_MAX_CDB)
return -EINVAL;
if (copy_from_user(cmd, hdr->cmdp, hdr->cmd_len))
return -EFAULT;
if (verify_command(file, cmd))
return -EPERM;
if (hdr->dxfer_len > (q->max_hw_sectors << 9))
return -EIO;
if (hdr->dxfer_len)
switch (hdr->dxfer_direction) {
default:
return -EINVAL;
case SG_DXFER_TO_FROM_DEV:
case SG_DXFER_TO_DEV:
writing = 1;
break;
case SG_DXFER_FROM_DEV:
break;
}
rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
if (!rq)
return -ENOMEM;
if (hdr->iovec_count) {
const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
struct sg_iovec *iov;
iov = kmalloc(size, GFP_KERNEL);
if (!iov) {
ret = -ENOMEM;
goto out;
}
if (copy_from_user(iov, hdr->dxferp, size)) {
kfree(iov);
ret = -EFAULT;
goto out;
}
ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count);
kfree(iov);
} else if (hdr->dxfer_len)
ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
if (ret)
goto out;
/*
* fill in request structure
*/
rq->cmd_len = hdr->cmd_len;
memcpy(rq->cmd, cmd, hdr->cmd_len);
if (sizeof(rq->cmd) != hdr->cmd_len)
memset(rq->cmd + hdr->cmd_len, 0, sizeof(rq->cmd) - hdr->cmd_len);
memset(sense, 0, sizeof(sense));
rq->sense = sense;
rq->sense_len = 0;
rq->flags |= REQ_BLOCK_PC;
bio = rq->bio;
/*
* bounce this after holding a reference to the original bio, it's
* needed for proper unmapping
*/
if (rq->bio)
blk_queue_bounce(q, &rq->bio);
rq->timeout = (hdr->timeout * HZ) / 1000;
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_TIMEOUT;
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, 0);
/* write to all output members */
hdr->status = 0xff & rq->errors;
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->data_len;
hdr->duration = ((jiffies - start_time) * 1000) / HZ;
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;
}
if (blk_rq_unmap_user(bio, hdr->dxfer_len))
ret = -EFAULT;
/* may not have succeeded, but output values written to control
* structure (struct sg_io_hdr). */
out:
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 file *file, struct request_queue *q,
struct gendisk *disk, 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 = kmalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
if (!buffer)
return -ENOMEM;
memset(buffer, 0, bytes);
}
rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
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 = verify_command(file, rq->cmd);
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_TIMEOUT;
break;
}
if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
err = DRIVER_ERROR << 24;
goto out;
}
memset(sense, 0, sizeof(sense));
rq->sense = sense;
rq->sense_len = 0;
rq->flags |= REQ_BLOCK_PC;
blk_execute_rq(q, disk, rq, 0);
out:
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:
kfree(buffer);
blk_put_request(rq);
return err;
}
EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
/* Send basic block requests */
static int __blk_send_generic(request_queue_t *q, struct gendisk *bd_disk, int cmd, int data)
{
struct request *rq;
int err;
rq = blk_get_request(q, WRITE, __GFP_WAIT);
rq->flags |= REQ_BLOCK_PC;
rq->data = NULL;
rq->data_len = 0;
rq->timeout = BLK_DEFAULT_TIMEOUT;
memset(rq->cmd, 0, sizeof(rq->cmd));
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(request_queue_t *q, struct gendisk *bd_disk, int data)
{
return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
}
int scsi_cmd_ioctl(struct file *file, struct gendisk *bd_disk, unsigned int cmd, void __user *arg)
{
request_queue_t *q;
int err;
q = bd_disk->queue;
if (!q)
return -ENXIO;
if (blk_get_queue(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(file, q, bd_disk, &hdr);
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 = cgc.timeout;
hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
hdr.cmd_len = sizeof(cgc.cmd);
err = sg_io(file, q, bd_disk, &hdr);
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(file, q, bd_disk, 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;
}
blk_put_queue(q);
return err;
}
EXPORT_SYMBOL(scsi_cmd_ioctl);
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