scsi_ioctl.c

基于组件方式开发操作系统的OSKIT源代码

#define __NO_VERSION__
#include <linux/module.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/page.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 <linux/blk.h>
#include "scsi.h"
#include "hosts.h"
#include <scsi/scsi_ioctl.h>

#define NORMAL_RETRIES 5   
#define NORMAL_TIMEOUT (10 * HZ)
#define FORMAT_UNIT_TIMEOUT (2 * 60 * 60 * HZ)
#define START_STOP_TIMEOUT (60 * HZ)
#define MOVE_MEDIUM_TIMEOUT (5 * 60 * HZ)
#define READ_ELEMENT_STATUS_TIMEOUT (5 * 60 * HZ)

#define MAX_BUF PAGE_SIZE

#define max(a,b) (((a) > (b)) ? (a) : (b))

/*
 * 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 *buffer)
{
    int temp, result;
    unsigned int len,slen;
    const char * string;
    
    if ((temp = host->hostt->present) && buffer) {
        result = verify_area(VERIFY_READ, buffer, sizeof(long));
        if (result) return result;

	get_user(len, (unsigned int *) buffer);
	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;
            result = verify_area(VERIFY_WRITE, buffer, len);
            if (result) return result;

	    copy_to_user (buffer, string, len);
	}
    }
    return temp;
}

/*
 * 
 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
 * The 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 transfered,
 * the ioctl will fail with error EINVAL.  MAX_BUF can be increased in
 * the future by increasing the size that scsi_malloc will accept.
 * 
 * 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 void scsi_ioctl_done (Scsi_Cmnd * SCpnt)
{
    struct request * req;
    
    req = &SCpnt->request;
    req->rq_status = RQ_SCSI_DONE; /* Busy, but indicate request done */
    
    if (req->sem != NULL) {
	up(req->sem);
    }
}   

static int ioctl_internal_command(Scsi_Device *dev, char * cmd,
				  int timeout, int retries)
{
    unsigned long flags;
    int result;
    Scsi_Cmnd * SCpnt;
    Scsi_Device * SDpnt;

    spin_lock_irqsave(&io_request_lock, flags);

    SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", cmd[0]));
    SCpnt = scsi_allocate_device(NULL, dev, 1);
    {
	struct semaphore sem = MUTEX_LOCKED;
	SCpnt->request.sem = &sem;
	scsi_do_cmd(SCpnt,  cmd, NULL,  0, scsi_ioctl_done,  timeout, retries);
	spin_unlock_irqrestore(&io_request_lock, flags);
	down(&sem);
        spin_lock_irqsave(&io_request_lock, flags);
        SCpnt->request.sem = NULL;
    }
    
    SCSI_LOG_IOCTL(2, printk("Ioctl returned  0x%x\n", SCpnt->result));

    if(driver_byte(SCpnt->result) != 0)
	switch(SCpnt->sense_buffer[2] & 0xf) {
	case ILLEGAL_REQUEST:
	    if(cmd[0] == ALLOW_MEDIUM_REMOVAL) dev->lockable = 0;
	    else printk("SCSI device (ioctl) reports ILLEGAL REQUEST.\n");
	    break;
	case NOT_READY: /* This happens if there is no disc in drive */
	    if(dev->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 (dev->removable){
		dev->changed = 1;
		SCpnt->result = 0; /* This is no longer considered an error */
		/* gag this error, VFS will log it anyway /axboe */
		/* printk(KERN_INFO "Disc change detected.\n"); */
		break;
	    };
	default: /* Fall through for non-removable media */
	    printk("SCSI error: host %d id %d lun %d return code = %x\n",
		   dev->host->host_no,
		   dev->id,
		   dev->lun,
		   SCpnt->result);
	    printk("\tSense class %x, sense error %x, extended sense %x\n",
		   sense_class(SCpnt->sense_buffer[0]),
		   sense_error(SCpnt->sense_buffer[0]),
		   SCpnt->sense_buffer[2] & 0xf);
	    
	};
    
    result = SCpnt->result;

    SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
    SDpnt = SCpnt->device;
    scsi_release_command(SCpnt);
    SCpnt = NULL;

    if (!SDpnt->was_reset && SDpnt->scsi_request_fn)
	(*SDpnt->scsi_request_fn)();

    wake_up(&SDpnt->device_wait);
    spin_unlock_irqrestore(&io_request_lock, flags);
    return result;
}

/*
 * This interface is depreciated - users should use the scsi generics
 * interface instead, as this is a more flexible approach to performing
 * generic SCSI commands on a device.
 */
int scsi_ioctl_send_command(Scsi_Device *dev, Scsi_Ioctl_Command *sic)
{
    unsigned long flags;
    char * buf;
    unsigned char cmd[12]; 
    char * cmd_in;
    Scsi_Cmnd * SCpnt;
    Scsi_Device * SDpnt;
    unsigned char opcode;
    int inlen, outlen, cmdlen;
    int needed, buf_needed;
    int timeout, retries, result;
    
    if (!sic)
	return -EINVAL;
    

    /*
     * Verify that we can read at least this much.
     */
    result = verify_area(VERIFY_READ, sic, sizeof (Scsi_Ioctl_Command));
    if (result) return result;

    /*
     * The structure that we are passed should look like:
     *
     * struct sdata {
     *	unsigned int inlen;
     *	unsigned int outlen;
     *	unsigned char  cmd[];  # However many bytes are used for cmd.
     *	unsigned char  data[];
     * };
     */
    get_user(inlen, &sic->inlen);
    get_user(outlen, &sic->outlen);
    
    /*
     * 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 instead.
     */
    if( inlen > MAX_BUF ) return -EINVAL;
    if( outlen > MAX_BUF ) return -EINVAL;

    cmd_in = sic->data;
    get_user(opcode, cmd_in); 
    
    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;
        spin_lock_irqsave(&io_request_lock, flags);
	buf = (char *) scsi_malloc(buf_needed);
        spin_unlock_irqrestore(&io_request_lock, flags);
	if (!buf) return -ENOMEM;
	memset(buf, 0, buf_needed);
    } else
	buf = NULL;
    
    /*
     * Obtain the command from the user's address space.
     */
    cmdlen = COMMAND_SIZE(opcode);

    result = verify_area(VERIFY_READ, cmd_in, 
                         cmdlen + inlen > MAX_BUF ? MAX_BUF : cmdlen + inlen);
    if (result) return result;

    copy_from_user ((void *) cmd,  cmd_in,  cmdlen);
    
    /*
     * Obtain the data to be sent to the device (if any).
     */
    copy_from_user ((void *) buf,  
                   (void *) (cmd_in + cmdlen), 
                   inlen);
    
    /*
     * Set the lun field to the correct value.
     */
    cmd[1] = ( cmd[1] & 0x1f ) | (dev->lun << 5);
    
    switch (opcode)
      {
      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;
      default:
 	timeout = NORMAL_TIMEOUT;
 	retries = NORMAL_RETRIES;
	break;
      }

#ifndef DEBUG_NO_CMD

    spin_lock_irqsave(&io_request_lock, flags);
    
    SCpnt = scsi_allocate_device(NULL, dev, 1);

    {
	struct semaphore sem = MUTEX_LOCKED;
	SCpnt->request.sem = &sem;
	scsi_do_cmd(SCpnt,  cmd,  buf, needed,  scsi_ioctl_done,
		    timeout, retries);
	spin_unlock_irqrestore(&io_request_lock, flags);
	down(&sem);
        SCpnt->request.sem = NULL;
    }
    
    /* 
     * If there was an error condition, pass the info back to the user. 
     */
    if(SCpnt->result) {
        result = verify_area(VERIFY_WRITE, 
                             cmd_in, 
                             sizeof(SCpnt->sense_buffer));
        if (result) return result;
        copy_to_user((void *) cmd_in,  
                    SCpnt->sense_buffer, 
                    sizeof(SCpnt->sense_buffer));
    } else {
        result = verify_area(VERIFY_WRITE, cmd_in, outlen);
        if (result) return result;
        copy_to_user ((void *) cmd_in,  buf,  outlen);
    }
    result = SCpnt->result;

    spin_lock_irqsave(&io_request_lock, flags);

    wake_up(&SCpnt->device->device_wait);
    SDpnt = SCpnt->device;
    scsi_release_command(SCpnt);
    SCpnt = NULL;

    if (buf) scsi_free(buf, buf_needed);
    
    if(SDpnt->scsi_request_fn)
	(*SDpnt->scsi_request_fn)();
    
    spin_unlock_irqrestore(&io_request_lock, flags);
    return result;
#else
    {
	int i;
	printk("scsi_ioctl : device %d.  command = ", dev->id);
	for (i = 0; i < 12; ++i)
	    printk("%02x ", cmd[i]);
	printk("\nbuffer =");
	for (i = 0; i < 20; ++i)
	    printk("%02x ", buf[i]);
	printk("\n");
	printk("inlen = %d, outlen = %d, cmdlen = %d\n",
	       inlen, outlen, cmdlen);
	printk("buffer = %d, cmd_in = %d\n", buffer, cmd_in);
    }
    return 0;
#endif
}

/*
 * 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 (Scsi_Device *dev, int cmd, void *arg)
{
    int result;
    char scsi_cmd[12];
    
    /* No idea how this happens.... */
    if (!dev) 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(dev) )
      {
        return -ENODEV;
      }
    
    switch (cmd) {
    case SCSI_IOCTL_GET_IDLUN:
        result = verify_area(VERIFY_WRITE, arg, sizeof (Scsi_Idlun));
        if (result) return result;

	put_user(dev->id 
                 + (dev->lun << 8) 
                 + (dev->channel << 16)
                 + ((dev->host->hostt->proc_dir->low_ino & 0xff) << 24),
		    &((Scsi_Idlun *) arg)->dev_id);
        put_user(dev->host->unique_id, &((Scsi_Idlun *) arg)->host_unique_id);
	return 0;
    case SCSI_IOCTL_GET_BUS_NUMBER:
        result = verify_area(VERIFY_WRITE, (void *) arg, sizeof(int));
        if (result) return result;
        put_user( dev->host->host_no, (int *) arg);
	return 0;
    case SCSI_IOCTL_TAGGED_ENABLE:
	if(!capable(CAP_SYS_ADMIN))  return -EACCES;
	if(!dev->tagged_supported) return -EINVAL;
	dev->tagged_queue = 1;
	dev->current_tag = 1;
	return 0;
    case SCSI_IOCTL_TAGGED_DISABLE:
	if(!capable(CAP_SYS_ADMIN))  return -EACCES;
	if(!dev->tagged_supported) return -EINVAL;
	dev->tagged_queue = 0;
	dev->current_tag = 0;
	return 0;
    case SCSI_IOCTL_PROBE_HOST:
	return ioctl_probe(dev->host, arg);
    case SCSI_IOCTL_SEND_COMMAND:
	if(!capable(CAP_SYS_ADMIN))  return -EACCES;
	return scsi_ioctl_send_command((Scsi_Device *) dev,
				       (Scsi_Ioctl_Command *) arg);
    case SCSI_IOCTL_DOORLOCK:
	if (!dev->removable || !dev->lockable) return 0;
	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
	scsi_cmd[1] = dev->lun << 5;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = SCSI_REMOVAL_PREVENT;
	return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd,
				      NORMAL_TIMEOUT, NORMAL_RETRIES);
	break;
    case SCSI_IOCTL_DOORUNLOCK:
	if (!dev->removable || !dev->lockable) return 0;
	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
	scsi_cmd[1] = dev->lun << 5;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = SCSI_REMOVAL_ALLOW;
	return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd,
				      NORMAL_TIMEOUT, NORMAL_RETRIES);
    case SCSI_IOCTL_TEST_UNIT_READY:
	scsi_cmd[0] = TEST_UNIT_READY;
	scsi_cmd[1] = dev->lun << 5;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = 0;
	return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd,
				      NORMAL_TIMEOUT, NORMAL_RETRIES);
	break;
    case SCSI_IOCTL_START_UNIT:
	scsi_cmd[0] = START_STOP;
	scsi_cmd[1] = dev->lun << 5;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = 1;
	return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd,
				      START_STOP_TIMEOUT, NORMAL_RETRIES);
	break;
    case SCSI_IOCTL_STOP_UNIT:
	scsi_cmd[0] = START_STOP;
	scsi_cmd[1] = dev->lun << 5;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = 0;
	return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd,
				      START_STOP_TIMEOUT, NORMAL_RETRIES);
	break;
    default :           
	if (dev->host->hostt->ioctl)
		return dev->host->hostt->ioctl(dev, cmd, arg);
	return -EINVAL;
    }
    return -EINVAL;
}

/*
 * Just like scsi_ioctl, only callable from kernel space with no 
 * fs segment fiddling.
 */

int kernel_scsi_ioctl (Scsi_Device *dev, int cmd, void *arg) {
#ifdef OSKIT
    panic("kernel_scsi_ioctl called but not supported");
#else
    mm_segment_t oldfs;
    int tmp;
    oldfs = get_fs();
    set_fs(get_ds());
    tmp = scsi_ioctl (dev, cmd, arg);
    set_fs(oldfs);
    return tmp;
#endif
}

/*
 * Overrides for Emacs so that we almost follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-indent-level: 4
 * c-brace-imaginary-offset: 0
 * c-brace-offset: -4
 * c-argdecl-indent: 4
 * c-label-offset: -4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: 0
 * indent-tabs-mode: nil
 * tab-width: 8
 * End:
 */