[linux-2.6-block.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_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.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, sdev_printk(KERN_INFO, sdev,
				      "Trying ioctl with scsi command %d\n", *cmd));

	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
				  &sshdr, timeout, retries, NULL);

	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
				      "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
				sdev_printk(KERN_INFO, sdev,
					    "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)
				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, sdev_printk(KERN_INFO, sdev,
				      "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);
	const char *name;

        if (!dev)
		return -ENXIO;

	name = dev_name(dev);

	/* compatibility with old ioctl which only returned
	 * 20 characters */
        return copy_to_user(arg, name, min(strlen(name), (size_t)20))
		? -EFAULT: 0;
}


/**
 * scsi_ioctl - Dispatch ioctl to scsi device
 * @sdev: scsi device receiving ioctl
 * @cmd: which ioctl is it
 * @arg: data associated with ioctl
 *
 * Description: 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 &struct scsi_device.
 */
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(sdev->request_queue, NULL, 0, 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, NULL);
	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);

/**
 * scsi_nonblockable_ioctl() - Handle SG_SCSI_RESET
 * @sdev: scsi device receiving ioctl
 * @cmd: Must be SC_SCSI_RESET
 * @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,BUS,HOST}
 * @ndelay: file mode O_NDELAY flag
 */
int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
			    void __user *arg, int ndelay)
{
	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 (ndelay) {
		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_TARGET:
			val = SCSI_TRY_RESET_TARGET;
			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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Changes:
	3	* Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
	4	* - get rid of some verify_areas and use __copy*user and __get/put_user
	5	* for the ones that remain
	6	*/
	7	#include <linux/module.h>
	8	#include <linux/blkdev.h>
	9	#include <linux/interrupt.h>
	10	#include <linux/errno.h>
	11	#include <linux/kernel.h>
	12	#include <linux/sched.h>
	13	#include <linux/mm.h>
	14	#include <linux/string.h>
	15	#include <asm/uaccess.h>
	16
	17	#include <scsi/scsi.h>
beb40487	18	#include <scsi/scsi_cmnd.h>
1da177e4 LT	19	#include <scsi/scsi_device.h>
	20	#include <scsi/scsi_eh.h>
	21	#include <scsi/scsi_host.h>
	22	#include <scsi/scsi_ioctl.h>
1da177e4 LT	23	#include <scsi/sg.h>
	24	#include <scsi/scsi_dbg.h>
	25
	26	#include "scsi_logging.h"
	27
	28	#define NORMAL_RETRIES 5
	29	#define IOCTL_NORMAL_TIMEOUT (10 * HZ)
1da177e4 LT	30
	31	#define MAX_BUF PAGE_SIZE
	32
32993523 CH	33	/**
	34	* ioctl_probe -- return host identification
	35	* @host: host to identify
	36	* @buffer: userspace buffer for identification
	37	*
	38	* Return an identifying string at @buffer, if @buffer is non-NULL, filling
	39	* to the length stored at * (int *) @buffer.
1da177e4	40	*/
1da177e4 LT	41	static int ioctl_probe(struct Scsi_Host host, void __user buffer)
	42	{
	43	unsigned int len, slen;
	44	const char *string;
1da177e4	45
32993523	46	if (buffer) {
1da177e4 LT	47	if (get_user(len, (unsigned int __user *) buffer))
	48	return -EFAULT;
	49
	50	if (host->hostt->info)
	51	string = host->hostt->info(host);
	52	else
	53	string = host->hostt->name;
	54	if (string) {
	55	slen = strlen(string);
	56	if (len > slen)
	57	len = slen + 1;
	58	if (copy_to_user(buffer, string, len))
	59	return -EFAULT;
	60	}
	61	}
32993523	62	return 1;
1da177e4 LT	63	}
	64
	65	/*
	66
	67	* The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
	68	* The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used.
	69	*
	70	* dev is the SCSI device struct ptr, (int ) arg is the length of the
	71	* input data, if any, not including the command string & counts,
	72	* ((int )arg + 1) is the output buffer size in bytes.
	73	*
	74	* (char ) ((int *) arg)[2] the actual command byte.
	75	*
	76	* Note that if more than MAX_BUF bytes are requested to be transferred,
	77	* the ioctl will fail with error EINVAL.
	78	*
	79	* This size does not include the initial lengths that were passed.
	80	*
	81	* The SCSI command is read from the memory location immediately after the
	82	* length words, and the input data is right after the command. The SCSI
	83	* routines know the command size based on the opcode decode.
	84	*
	85	* The output area is then filled in starting from the command byte.
	86	*/
	87
	88	static int ioctl_internal_command(struct scsi_device sdev, char cmd,
	89	int timeout, int retries)
	90	{
1da177e4 LT	91	int result;
	92	struct scsi_sense_hdr sshdr;
	93
e5f73ce3 HR	94	SCSI_LOG_IOCTL(1, sdev_printk(KERN_INFO, sdev,
e5f73ce3 HR	95	"Trying ioctl with scsi command %d\n", *cmd));
1da177e4	96
1cf72699	97	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
f4f4e47e	98	&sshdr, timeout, retries, NULL);
1da177e4	99
e5f73ce3 HR	100	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
e5f73ce3 HR	101	"Ioctl returned 0x%x\n", result));
1da177e4	102
1cf72699	103	if ((driver_byte(result) & DRIVER_SENSE) &&
ea73a9f2	104	(scsi_sense_valid(&sshdr))) {
1da177e4 LT	105	switch (sshdr.sense_key) {
	106	case ILLEGAL_REQUEST:
	107	if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
	108	sdev->lockable = 0;
	109	else
e5f73ce3 HR	110	sdev_printk(KERN_INFO, sdev,
	111	"ioctl_internal_command: "
	112	"ILLEGAL REQUEST "
	113	"asc=0x%x ascq=0x%x\n",
	114	sshdr.asc, sshdr.ascq);
1da177e4 LT	115	break;
1da177e4 LT	116	case NOT_READY: /* This happens if there is no disc in drive */
a75ad3c2	117	if (sdev->removable)
1da177e4	118	break;
1da177e4 LT	119	case UNIT_ATTENTION:
	120	if (sdev->removable) {
	121	sdev->changed = 1;
1cf72699	122	result = 0; /* This is no longer considered an error */
1da177e4 LT	123	break;
	124	}
	125	default: /* Fall through for non-removable media */
9ccfc756 JB	126	sdev_printk(KERN_INFO, sdev,
	127	"ioctl_internal_command return code = %x\n",
	128	result);
ea73a9f2	129	scsi_print_sense_hdr(" ", &sshdr);
1da177e4 LT	130	break;
	131	}
	132	}
	133
e5f73ce3 HR	134	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
e5f73ce3 HR	135	"IOCTL Releasing command\n"));
1da177e4 LT	136	return result;
	137	}
	138
	139	int scsi_set_medium_removal(struct scsi_device *sdev, char state)
	140	{
	141	char scsi_cmd[MAX_COMMAND_SIZE];
	142	int ret;
	143
	144	if (!sdev->removable \|\| !sdev->lockable)
	145	return 0;
	146
	147	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
	148	scsi_cmd[1] = 0;
	149	scsi_cmd[2] = 0;
	150	scsi_cmd[3] = 0;
	151	scsi_cmd[4] = state;
	152	scsi_cmd[5] = 0;
	153
	154	ret = ioctl_internal_command(sdev, scsi_cmd,
	155	IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
	156	if (ret == 0)
	157	sdev->locked = (state == SCSI_REMOVAL_PREVENT);
	158	return ret;
	159	}
	160	EXPORT_SYMBOL(scsi_set_medium_removal);
	161
1da177e4 LT	162	/*
	163	* The scsi_ioctl_get_pci() function places into arg the value
	164	* pci_dev::slot_name (8 characters) for the PCI device (if any).
	165	* Returns: 0 on success
	166	* -ENXIO if there isn't a PCI device pointer
	167	* (could be because the SCSI driver hasn't been
	168	* updated yet, or because it isn't a SCSI
	169	* device)
	170	* any copy_to_user() error on failure there
	171	*/
	172	static int scsi_ioctl_get_pci(struct scsi_device sdev, void __user arg)
	173	{
	174	struct device *dev = scsi_get_device(sdev->host);
71610f55	175	const char *name;
1da177e4 LT	176
	177	if (!dev)
	178	return -ENXIO;
71610f55 KS	179
	180	name = dev_name(dev);
	181
	182	/* compatibility with old ioctl which only returned
	183	* 20 characters */
	184	return copy_to_user(arg, name, min(strlen(name), (size_t)20))
	185	? -EFAULT: 0;
1da177e4 LT	186	}
	187
	188
eb44820c RL	189	/**
	190	* scsi_ioctl - Dispatch ioctl to scsi device
	191	* @sdev: scsi device receiving ioctl
	192	* @cmd: which ioctl is it
	193	* @arg: data associated with ioctl
	194	*
	195	* Description: The scsi_ioctl() function differs from most ioctls in that it
	196	* does not take a major/minor number as the dev field. Rather, it takes
	197	* a pointer to a &struct scsi_device.
1da177e4 LT	198	*/
	199	int scsi_ioctl(struct scsi_device sdev, int cmd, void __user arg)
	200	{
	201	char scsi_cmd[MAX_COMMAND_SIZE];
	202
	203	/* No idea how this happens.... */
	204	if (!sdev)
	205	return -ENXIO;
	206
	207	/*
	208	* If we are in the middle of error recovery, don't let anyone
	209	* else try and use this device. Also, if error recovery fails, it
	210	* may try and take the device offline, in which case all further
	211	* access to the device is prohibited.
	212	*/
	213	if (!scsi_block_when_processing_errors(sdev))
	214	return -ENODEV;
	215
	216	/* Check for deprecated ioctls ... all the ioctls which don't
	217	* follow the new unique numbering scheme are deprecated */
	218	switch (cmd) {
	219	case SCSI_IOCTL_SEND_COMMAND:
	220	case SCSI_IOCTL_TEST_UNIT_READY:
	221	case SCSI_IOCTL_BENCHMARK_COMMAND:
	222	case SCSI_IOCTL_SYNC:
	223	case SCSI_IOCTL_START_UNIT:
	224	case SCSI_IOCTL_STOP_UNIT:
	225	printk(KERN_WARNING "program %s is using a deprecated SCSI "
	226	"ioctl, please convert it to SG_IO\n", current->comm);
	227	break;
	228	default:
	229	break;
	230	}
	231
	232	switch (cmd) {
	233	case SCSI_IOCTL_GET_IDLUN:
	234	if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
	235	return -EFAULT;
	236
	237	__put_user((sdev->id & 0xff)
	238	+ ((sdev->lun & 0xff) << 8)
	239	+ ((sdev->channel & 0xff) << 16)
	240	+ ((sdev->host->host_no & 0xff) << 24),
	241	&((struct scsi_idlun __user *)arg)->dev_id);
	242	__put_user(sdev->host->unique_id,
	243	&((struct scsi_idlun __user *)arg)->host_unique_id);
	244	return 0;
	245	case SCSI_IOCTL_GET_BUS_NUMBER:
	246	return put_user(sdev->host->host_no, (int __user *)arg);
	247	case SCSI_IOCTL_PROBE_HOST:
	248	return ioctl_probe(sdev->host, arg);
	249	case SCSI_IOCTL_SEND_COMMAND:
	250	if (!capable(CAP_SYS_ADMIN) \|\| !capable(CAP_SYS_RAWIO))
	251	return -EACCES;
e915e872	252	return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
1da177e4 LT	253	case SCSI_IOCTL_DOORLOCK:
	254	return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
	255	case SCSI_IOCTL_DOORUNLOCK:
	256	return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
	257	case SCSI_IOCTL_TEST_UNIT_READY:
	258	return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
001aac25	259	NORMAL_RETRIES, NULL);
1da177e4 LT	260	case SCSI_IOCTL_START_UNIT:
	261	scsi_cmd[0] = START_STOP;
	262	scsi_cmd[1] = 0;
	263	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	264	scsi_cmd[4] = 1;
	265	return ioctl_internal_command(sdev, scsi_cmd,
	266	START_STOP_TIMEOUT, NORMAL_RETRIES);
	267	case SCSI_IOCTL_STOP_UNIT:
	268	scsi_cmd[0] = START_STOP;
	269	scsi_cmd[1] = 0;
	270	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	271	scsi_cmd[4] = 0;
	272	return ioctl_internal_command(sdev, scsi_cmd,
	273	START_STOP_TIMEOUT, NORMAL_RETRIES);
	274	case SCSI_IOCTL_GET_PCI:
	275	return scsi_ioctl_get_pci(sdev, arg);
	276	default:
	277	if (sdev->host->hostt->ioctl)
	278	return sdev->host->hostt->ioctl(sdev, cmd, arg);
	279	}
	280	return -EINVAL;
	281	}
	282	EXPORT_SYMBOL(scsi_ioctl);
	283
eb44820c	284	/**
decf67e3	285	* scsi_nonblockable_ioctl() - Handle SG_SCSI_RESET
eb44820c RL	286	* @sdev: scsi device receiving ioctl
	287	* @cmd: Must be SC_SCSI_RESET
	288	* @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,BUS,HOST}
decf67e3	289	* @ndelay: file mode O_NDELAY flag
1da177e4 LT	290	*/
1da177e4 LT	291	int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
83ff6fe8	292	void __user *arg, int ndelay)
1da177e4 LT	293	{
	294	int val, result;
	295
	296	/* The first set of iocts may be executed even if we're doing
	297	* error processing, as long as the device was opened
	298	* non-blocking */
83ff6fe8	299	if (ndelay) {
939647ee	300	if (scsi_host_in_recovery(sdev->host))
1da177e4 LT	301	return -ENODEV;
	302	} else if (!scsi_block_when_processing_errors(sdev))
	303	return -ENODEV;
	304
	305	switch (cmd) {
	306	case SG_SCSI_RESET:
	307	result = get_user(val, (int __user *)arg);
	308	if (result)
	309	return result;
	310	if (val == SG_SCSI_RESET_NOTHING)
	311	return 0;
	312	switch (val) {
	313	case SG_SCSI_RESET_DEVICE:
	314	val = SCSI_TRY_RESET_DEVICE;
	315	break;
3f9daedf MC	316	case SG_SCSI_RESET_TARGET:
	317	val = SCSI_TRY_RESET_TARGET;
	318	break;
1da177e4 LT	319	case SG_SCSI_RESET_BUS:
	320	val = SCSI_TRY_RESET_BUS;
	321	break;
	322	case SG_SCSI_RESET_HOST:
	323	val = SCSI_TRY_RESET_HOST;
	324	break;
	325	default:
	326	return -EINVAL;
	327	}
	328	if (!capable(CAP_SYS_ADMIN) \|\| !capable(CAP_SYS_RAWIO))
	329	return -EACCES;
	330	return (scsi_reset_provider(sdev, val) ==
	331	SUCCESS) ? 0 : -EIO;
	332	}
	333	return -ENODEV;
	334	}
	335	EXPORT_SYMBOL(scsi_nonblockable_ioctl);