kernel/blk_drv/scsi/scsi

/* */
This source file includes following definitions.
ioctl_probe
scsi_ioctl_done
ioctl_internal_command
ioctl_command
scsi_ioctl
   1 #include <asm/io.h>
   2 #include <asm/segment.h>
   3 #include <asm/system.h>
   4 
   5 #include <linux/errno.h>
   6 #include <linux/kernel.h>
   7 #include <linux/sched.h>
   8 #include <linux/string.h>
   9 
  10 #include "../blk.h"
  11 #include "scsi.h"
  12 #include "hosts.h"
  13 #include "scsi_ioctl.h"
  14 
  15 #define MAX_RETRIES 5   
  16 #define MAX_TIMEOUT 200
  17 #define MAX_BUF 4096
  18 
  19 #define max(a,b) (((a) > (b)) ? (a) : (b))
  20 
  21 /*
  22  * If we are told to probe a host, we will return 0 if  the host is not
  23  * present, 1 if the host is present, and will return an identifying
  24  * string at *arg, if arg is non null, filling to the length stored at
  25  * (int *) arg
  26  */
  27 
  28 static int ioctl_probe(int dev, void *buffer)
     /*  */
  29 {
  30         int temp;
  31         unsigned int len,slen;
  32         const char * string;
  33         
  34         if ((temp = scsi_hosts[dev].present) && buffer) {
  35                 len = get_fs_long ((int *) buffer);
  36                 string = scsi_hosts[dev].info();
  37                 slen = strlen(string);
  38                 if (len > slen)
  39                         len = slen + 1;
  40                 verify_area(VERIFY_WRITE, buffer, len);
  41                 memcpy_tofs (buffer, string, len);
  42         }
  43         return temp;
  44 }
  45 
  46 /*
  47  * 
  48  * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
  49  * The MAX_TIMEOUT and MAX_RETRIES  variables are used.  
  50  * 
  51  * dev is the SCSI device struct ptr, *(int *) arg is the length of the
  52  * input data, if any, not including the command string & counts, 
  53  * *((int *)arg + 1) is the output buffer size in bytes.
  54  * 
  55  * *(char *) ((int *) arg)[2] the actual command byte.   
  56  * 
  57  * Note that no more than MAX_BUF data bytes will be transfered.  Since
  58  * SCSI block device size is 512 bytes, I figured 1K was good.
  59  * but (WDE) changed it to 8192 to handle large bad track buffers.
  60  * ERY: I changed this to a dynamic allocation using scsi_malloc - we were
  61  * getting a kernel stack overflow which was crashing the system when we
  62  * were using 8192 bytes.
  63  * 
  64  * This size *does not* include the initial lengths that were passed.
  65  * 
  66  * The SCSI command is read from the memory location immediately after the
  67  * length words, and the input data is right after the command.  The SCSI
  68  * routines know the command size based on the opcode decode.  
  69  * 
  70  * The output area is then filled in starting from the command byte. 
  71  */
  72 
  73 static void scsi_ioctl_done (Scsi_Cmnd * SCpnt)
     /*  */
  74 {
  75   struct request * req;
  76   struct task_struct * p;
  77   
  78   req = &SCpnt->request;
  79   req->dev = 0xfffe; /* Busy, but indicate request done */
  80   
  81   if ((p = req->waiting) != NULL) {
  82     req->waiting = NULL;
  83     p->state = TASK_RUNNING;
  84     if (p->counter > current->counter)
  85       need_resched = 1;
  86   }
  87 }       
  88 
  89 static int ioctl_internal_command(Scsi_Device *dev, char * cmd)
     /*  */
  90 {
  91         int host, result;
  92         Scsi_Cmnd * SCpnt;
  93 
  94         host = dev->host_no;
  95 
  96         SCpnt = allocate_device(NULL, dev->index, 1);
  97         scsi_do_cmd(SCpnt,  cmd, NULL,  0,
  98                         scsi_ioctl_done,  MAX_TIMEOUT,
  99                         MAX_RETRIES);
 100 
 101         if (SCpnt->request.dev != 0xfffe){
 102           SCpnt->request.waiting = current;
 103           current->state = TASK_UNINTERRUPTIBLE;
 104           while (SCpnt->request.dev != 0xfffe) schedule();
 105         };
 106 
 107         if(driver_byte(SCpnt->result) != 0)
 108           switch(SCpnt->sense_buffer[2] & 0xf) {
 109           case ILLEGAL_REQUEST:
 110             if(cmd[0] == ALLOW_MEDIUM_REMOVAL) dev->lockable = 0;
 111             else printk("SCSI device (ioctl) reports ILLEGAL REQUEST.\n");
 112             break;
 113           case NOT_READY: /* This happens if there is no disc in drive */
 114             if(dev->removable){
 115               printk("Device not ready.  Make sure there is a disc in the drive.\n");
 116               break;
 117             };
 118           case UNIT_ATTENTION:
 119             if (dev->removable){
 120               dev->changed = 1;
 121               SCpnt->result = 0; /* This is no longer considered an error */
 122               printk("Disc change detected.\n");
 123               break;
 124             };
 125           default: /* Fall through for non-removable media */
 126             printk("SCSI CD error: host %d id %d lun %d return code = %x\n",
 127                    dev->host_no,
 128                    dev->id,
 129                    dev->lun,
 130                    SCpnt->result);
 131             printk("\tSense class %x, sense error %x, extended sense %x\n",
 132                    sense_class(SCpnt->sense_buffer[0]),
 133                    sense_error(SCpnt->sense_buffer[0]),
 134                    SCpnt->sense_buffer[2] & 0xf);
 135 
 136           };
 137 
 138         result = SCpnt->result;
 139         SCpnt->request.dev = -1;  /* Mark as not busy */
 140         wake_up(&scsi_devices[SCpnt->index].device_wait);
 141         return result;
 142 }
 143 
 144 static int ioctl_command(Scsi_Device *dev, void *buffer)
     /*  */
 145 {
 146         char * buf;
 147         char cmd[12];
 148         char * cmd_in;
 149         Scsi_Cmnd * SCpnt;
 150         unsigned char opcode;
 151         int inlen, outlen, cmdlen, host;
 152         int needed;
 153         int result;
 154 
 155         if (!buffer)
 156                 return -EINVAL;
 157         
 158         inlen = get_fs_long((int *) buffer);
 159         outlen = get_fs_long( ((int *) buffer) + 1);
 160 
 161         cmd_in = (char *) ( ((int *)buffer) + 2);
 162         opcode = get_fs_byte(cmd_in); 
 163 
 164         needed = (inlen > outlen ? inlen : outlen);
 165         if(needed){
 166           needed = (needed + 511) & ~511;
 167           if (needed > MAX_BUF) needed = MAX_BUF;
 168           buf = scsi_malloc(needed);
 169           if (!buf) return -ENOMEM;
 170         } else
 171           buf = NULL;
 172 
 173         memcpy_fromfs ((void *) cmd,  cmd_in,  cmdlen = COMMAND_SIZE (opcode));
 174         memcpy_fromfs ((void *) buf,  (void *) (cmd_in + cmdlen), inlen > MAX_BUF ? MAX_BUF : inlen);
 175         host = dev->host_no;
 176         cmd[1] = ( cmd[1] & 0x1f ) | (dev->lun << 5);
 177 
 178 #ifndef DEBUG_NO_CMD
 179         
 180         SCpnt = allocate_device(NULL, dev->index, 1);
 181 
 182         scsi_do_cmd(SCpnt,  cmd,  buf,  ((outlen > MAX_BUF) ? 
 183                         MAX_BUF : outlen),  scsi_ioctl_done,  MAX_TIMEOUT, 
 184                         MAX_RETRIES);
 185 
 186         if (SCpnt->request.dev != 0xfffe){
 187           SCpnt->request.waiting = current;
 188           current->state = TASK_UNINTERRUPTIBLE;
 189           while (SCpnt->request.dev != 0xfffe) schedule();
 190         };
 191 
 192         result = verify_area(VERIFY_WRITE, cmd_in, (outlen > MAX_BUF) ? MAX_BUF  : outlen);
 193         if (result)
 194                 return result;
 195         memcpy_tofs ((void *) cmd_in,  buf,  (outlen > MAX_BUF) ? MAX_BUF  : outlen);
 196         result = SCpnt->result;
 197         SCpnt->request.dev = -1;  /* Mark as not busy */
 198         if (buf) scsi_free(buf, needed);
 199         wake_up(&scsi_devices[SCpnt->index].device_wait);
 200         return result;
 201 #else
 202         {
 203         int i;
 204         printk("scsi_ioctl : device %d.  command = ", dev->id);
 205         for (i = 0; i < 10; ++i)
 206                 printk("%02x ", cmd[i]);
 207         printk("\nbuffer =");
 208         for (i = 0; i < 20; ++i)
 209                 printk("%02x ", buf[i]);
 210         printk("\n");
 211         printk("inlen = %d, outlen = %d, cmdlen = %d\n",
 212                 inlen, outlen, cmdlen);
 213         printk("buffer = %d, cmd_in = %d\n", buffer, cmd_in);
 214         }
 215         return 0;
 216 #endif
 217 }
 218 
 219         
 220 /*
 221         the scsi_ioctl() function differs from most ioctls in that it does
 222         not take a major/minor number as the dev filed.  Rather, it takes
 223         a pointer to a scsi_devices[] element, a structure. 
 224 */
 225 int scsi_ioctl (Scsi_Device *dev, int cmd, void *arg)
     /*  */
 226 {
 227         char scsi_cmd[10];
 228 
 229         if ((cmd != 0 && dev->index > NR_SCSI_DEVICES))
 230                 return -ENODEV;
 231         if ((cmd == 0 && dev->host_no > max_scsi_hosts))
 232                 return -ENODEV;
 233         
 234         switch (cmd) {
 235                 case SCSI_IOCTL_GET_IDLUN:
 236                         verify_area(VERIFY_WRITE, (void *) arg, sizeof(int));
 237                         put_fs_long(dev->id + (dev->lun << 8) + 
 238                                     (dev->host_no << 16), (long *) arg);
 239                         return 0;
 240                 case SCSI_IOCTL_PROBE_HOST:
 241                         return ioctl_probe(dev->host_no, arg);
 242                 case SCSI_IOCTL_SEND_COMMAND:
 243                         return ioctl_command((Scsi_Device *) dev, arg);
 244                 case SCSI_IOCTL_DOORLOCK:
 245                         if (!dev->removable || !dev->lockable) return 0;
 246                         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 247                         scsi_cmd[1] = dev->lun << 5;
 248                         scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 249                         scsi_cmd[4] = SCSI_REMOVAL_PREVENT;
 250                         return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd);
 251                         break;
 252                 case SCSI_IOCTL_DOORUNLOCK:
 253                         if (!dev->removable || !dev->lockable) return 0;
 254                         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 255                         scsi_cmd[1] = dev->lun << 5;
 256                         scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 257                         scsi_cmd[4] = SCSI_REMOVAL_ALLOW;
 258                         return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd);
 259                 case SCSI_IOCTL_TEST_UNIT_READY:
 260                         scsi_cmd[0] = TEST_UNIT_READY;
 261                         scsi_cmd[1] = dev->lun << 5;
 262                         scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 263                         scsi_cmd[4] = 0;
 264                         return ioctl_internal_command((Scsi_Device *) dev, scsi_cmd);
 265                         break;
 266                 default :                       
 267                         return -EINVAL;
 268         }
 269 }
/* */
root/kernel/blk_drv/scsi/scsi_ioctl.c

DEFINITIONS
