linux/block/scsi_ioctl.c
Alan Stern 44ec95425c [SCSI] sg: cap reserved_size values at max_sectors
This patch (as857) modifies the SG_GET_RESERVED_SIZE and
SG_SET_RESERVED_SIZE ioctls in the sg driver, capping the values at
the device's request_queue's max_sectors value.  This will permit
cdrecord to obtain a legal value for the maximum transfer length,
fixing Bugzilla #7026.

The patch also caps the initial reserved_size value.  There's no
reason to have a reserved buffer larger than max_sectors, since it
would be impossible to use the extra space.

The corresponding ioctls in the block layer are modified similarly,
and the initial value for the reserved_size is set as large as
possible.  This will effectively make it default to max_sectors.
Note that the actual value is meaningless anyway, since block devices
don't have a reserved buffer.

Finally, the BLKSECTGET ioctl is added to sg, so that there will be a
uniform way for users to determine the actual max_sectors value for
any raw SCSI transport.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2007-04-17 18:09:56 -04:00

654 lines
16 KiB
C

/*
* 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)
{
unsigned val = min(q->sg_reserved_size, q->max_sectors << 9);
return put_user(val, 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, timeout;
int writing = 0, ret = 0;
struct request *rq;
char sense[SCSI_SENSE_BUFFERSIZE];
unsigned char cmd[BLK_MAX_CDB];
struct bio *bio;
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_DEV:
writing = 1;
break;
case SG_DXFER_TO_FROM_DEV:
case SG_DXFER_FROM_DEV:
break;
}
rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
if (!rq)
return -ENOMEM;
/*
* fill in request structure
*/
rq->cmd_len = hdr->cmd_len;
memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
memcpy(rq->cmd, cmd, hdr->cmd_len);
memset(sense, 0, sizeof(sense));
rq->sense = sense;
rq->sense_len = 0;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
timeout = msecs_to_jiffies(hdr->timeout);
rq->timeout = (timeout < INT_MAX) ? timeout : INT_MAX;
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_TIMEOUT;
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,
hdr->dxfer_len);
kfree(iov);
} else if (hdr->dxfer_len)
ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
if (ret)
goto out;
bio = rq->bio;
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))
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->cmd_type = REQ_TYPE_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->cmd_type = REQ_TYPE_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);