linux/drivers/scsi/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

316 lines
8.9 KiB
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
/**
* ioctl_probe -- return host identification
* @host: host to identify
* @buffer: userspace buffer for identification
*
* Return an identifying string at @buffer, if @buffer is non-NULL, filling
* to the length stored at * (int *) @buffer.
*/
static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
{
unsigned int len, slen;
const char *string;
if (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 1;
}
/*
* 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)
{
int result;
struct scsi_sense_hdr sshdr;
SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd));
result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
&sshdr, timeout, retries);
SCSI_LOG_IOCTL(2, printk("Ioctl returned 0x%x\n", result));
if ((driver_byte(result) & DRIVER_SENSE) &&
(scsi_sense_valid(&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;
result = 0; /* This is no longer considered an error */
break;
}
default: /* Fall through for non-removable media */
sdev_printk(KERN_INFO, sdev,
"ioctl_internal_command return code = %x\n",
result);
scsi_print_sense_hdr(" ", &sshdr);
break;
}
}
SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
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);
/*
* 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 sg_scsi_ioctl(NULL, sdev->request_queue, NULL, 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 (scsi_host_in_recovery(sdev->host))
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);