1 DKIO(7I)                        Ioctl Requests                        DKIO(7I)
   2 
   3 NAME
   4      dkio - disk control operations
   5 
   6 SYNOPSIS
   7      #include <sys/dkio.h>
   8      #include <sys/vtoc.h>
   9 
  10 DESCRIPTION
  11      Disk drivers support a set of ioctl(2) requests for disk controller,
  12      geometry, and partition information.  Basic to these ioctl(2) requests
  13      are the definitions in <sys/dkio.h>.
  14 
  15 IOCTLS
  16      The following ioctl(2) requests set and/or retrieve the current disk
  17      controller, partitions, or geometry information on all architectures:
  18 
  19      DKIOCINFO
  20 
  21         The argument is a pointer to a dk_cinfo structure (described below).
  22         This structure tells the controller-type and attributes regarding bad-
  23         block processing done on the controller.
  24 
  25           /*
  26            * Structures and definitions for disk I/O control commands
  27            */
  28           #define DK_DEVLEN 16   /* device name max length, */
  29                                  /* including unit # and NULL */
  30 
  31           /* Used for controller info */
  32           struct dk_cinfo {
  33                char      dki_cname[DK_DEVLEN];    /* controller name */
  34                                                   /* (no unit #) */
  35                ushort_t  dki_ctype;               /* controller type */
  36                ushort_t  dki_flags;               /* flags */
  37                ushort_t  dki_cnum;                /* controller number */
  38                uint_t    dki_addr;                /* controller address */
  39                uint_t    dki_space;               /* controller bus type */
  40                uint_t    dki_prio;                /* interrupt priority */
  41                uint_t    dki_vec;                 /* interrupt vector */
  42                char      dki_dname[DK_DEVLEN];    /* drive name (no unit #) */
  43                uint_t    dki_unit;                /* unit number */
  44                uint_t    dki_slave;               /* slave number */
  45                ushort_t  dki_partition;           /* partition number */
  46                ushort_t  dki_maxtransfer;         /* maximum transfer size */
  47                                                   /* in DEV_BSIZE */
  48                };
  49 
  50                /*
  51                 * Controller types
  52                 */
  53                #define DKC_UNKNOWN      0
  54                #define DKC_CDROM        1         /* CD-ROM, SCSI or other */
  55                #define DKC_WDC2880      2
  56                #define DKC_XXX_0        3         /* unassigned */
  57                #define DKC_XXX_1        4         /* unassigned */
  58                #define DKC_DSD5215      5
  59                #define DKC_ACB4000      7
  60                #define DKC_XXX_2        9         /* unassigned */
  61                #define DKC_NCRFLOPPY    10
  62                #define DKC_SMSFLOPPY    12
  63                #define DKC_SCSI_CCS     13        /* SCSI CCS compatible */
  64                #define DKC_INTEL82072   14        /* native floppy chip */
  65                #define DKC_INTEL82077   19        /* 82077 floppy disk */
  66                                                   /* controller */
  67                #define DKC_DIRECT       20        /* Intel direct attached */
  68                                                   /* device (IDE) */
  69                #define DKC_PCMCIA_MEM   21        /* PCMCIA memory disk-like */
  70                                                   /* type */
  71                #define DKC_PCMCIA_ATA   22        /* PCMCIA AT Attached type */
  72 
  73                /*
  74                 * Sun reserves up through 1023
  75                 */
  76 
  77                #define DKC_CUSTOMER_BASE  1024
  78 
  79                /*
  80                 * Flags
  81                 */
  82                #define DKI_BAD144       0x01          /* use  DEC  std  144  */
  83                                                       /* bad  sector fwding */
  84                #define DKI_MAPTRK       0x02          /* controller does */
  85                                                       /* track mapping */
  86                #define DKI_FMTTRK       0x04          /* formats only  full
  87                                                       /* track at a time */
  88                #define DKI_FMTVOL       0x08          /* formats only full */
  89                                                       /* volume at a time */
  90                #define DKI_FMTCYL       0x10          /* formats only full */
  91                                                       /* cylinders at a time */
  92                #define DKI_HEXUNIT      0x20          /* unit number printed */
  93                                                       /* as 3 hexdigits */
  94                #define DKI_PCMCIA_PFD   0x40          /* PCMCIA pseudo-floppy */
  95                                                       /* memory card */
  96 
  97      DKIOCGAPART
  98 
  99         The argument is a pointer to a dk_allmap structure (described below).
 100         This ioctl(2) gets the controller's notion of the current partition
 101         table for disk drive.
 102 
 103      DKIOCSAPART
 104 
 105         The argument is a pointer to a dk_allmap structure (described below).
 106         This ioctl(2) sets the controller's notion of the partition table
 107         without changing the disk itself.
 108 
 109           /*
 110            * Partition map (part of dk_label)
 111            */
 112           struct dk_map {
 113                daddr_t dkl_cylno;     /* starting cylinder */
 114                daddr_t dkl_nblk;      /* number of blocks */
 115           };
 116 
 117           /*
 118            * Used for all partitions
 119            */
 120           struct dk_allmap {
 121               struct dk_map    dka_map[NDKMAP];
 122           };
 123 
 124      DKIOCGGEOM
 125 
 126         The argument is a pointer to a dk_geom structure (described below).
 127         This ioctl(2) gets the controller's notion of the current geometry of
 128         the disk drive.
 129 
 130      DKIOCSGEOM
 131 
 132         The argument is a pointer to a dk_geom structure (described below).
 133         This ioctl(2) sets the controller's notion of the geometry without
 134         changing the disk itself.
 135 
 136      DKIOCGVTOC
 137 
 138         The argument is a pointer to a vtoc structure (described below).  This
 139         ioctl(2) returns the device's current volume table of contents (VTOC).
 140         For disks larger than 1TB, DKIOCGEXTVTOC must be used instead.
 141 
 142      DKIOCSVTOC
 143 
 144         The argument is a pointer to a vtoc structure (described below).  This
 145         ioctl(2) changes the VTOC associated with the device.  For disks
 146         larger than 1TB, DKIOCSEXTVTOC must be used instead.
 147 
 148           struct partition {
 149               ushort_t      p_tag;         /* ID tag of partition */
 150               ushort_t      p_flag;        /* permission flags */
 151               daddr_t       p_start;       /* start sector of partition */
 152               long          p_size;        /* # of blocks in partition */
 153           };
 154 
 155         If DKIOCSVTOC is used with a floppy diskette, the p_start field must
 156         be the first sector of a cylinder.  To compute the number of sectors
 157         per cylinder, multiply the number of heads by the number of sectors
 158         per track.
 159 
 160           struct vtoc {
 161               unsigned long     v_bootinfo[3];        /* info needed by mboot */
 162                                                       /* (unsupported) */
 163               unsigned long     v_sanity;             /* to verify vtoc */
 164                                                       /* sanity */
 165               unsigned long     v_version;            /* layout version */
 166               char              v_volume[LEN_DKL_VVOL]; /* volume name */
 167               ushort_t          v_sectorsz;           /* sector size in bytes */
 168               ushort_t          v_nparts;             /* number of partitions */
 169               unsigned long     v_reserved[10];       /* free space */
 170               struct partition  v_part[V_NUMPAR];     /* partition headers */
 171               time_t            timestamp[V_NUMPAR];  /* partition timestamp */
 172                                                       /* (unsupported) */
 173               char              v_asciilabel[LEN_DKL_ASCII]; /* compatibility */
 174           };
 175 
 176           /*
 177            * Partition permission flags
 178            */
 179           #define V_UNMNT      0x01    /* Unmountable partition */
 180           #define V_RONLY      0x10    /* Read only */
 181 
 182           /*
 183            * Partition identification tags
 184            */
 185           #define V_UNASSIGNED   0x00  /* unassigned partition */
 186           #define V_BOOT         0x01  /* Boot partition */
 187           #define V_ROOT         0x02  /* Root filesystem */
 188           #define V_SWAP         0x03  /* Swap filesystem */
 189           #define V_USR          0x04  /* Usr filesystem */
 190           #define V_BACKUP       0x05  /* full disk */
 191           #define V_VAR          0x07  /* Var partition */
 192           #define V_HOME         0x08  /* Home partition */
 193           #define V_ALTSCTR      0x09  /* Alternate sector partition */
 194 
 195      DKIOCGEXTVTOC
 196 
 197         The argument is a pointer to an extvtoc structure (described below).
 198         This ioctl returns the device's current volume table of contents
 199         (VTOC).  VTOC is extended to support a disk up to 2TB in size.  For
 200         disks larger than 1TB this ioctl must be used instead of DKIOCGVTOC.
 201 
 202      DKIOCSEXTVTOC
 203 
 204         The argument is a pointer to an extvtoc structure (described below).
 205         This ioctl changes the VTOC associated with the device.  VTOC is
 206         extended to support a disk up to 2TB in size.  For disks larger than
 207         1TB this ioctl must be used instead of DKIOCSVTOC.
 208 
 209           struct extpartition {
 210               ushort_t p_tag;         /* ID tag of partition */
 211               ushort_t p_flag;        /* permission flags */
 212               ushort_t p_pad[2];      /* reserved */
 213               diskaddr_t p_start;     /* start sector no of partition */
 214               diskaddr_t p_size;      /* # of blocks in partition */
 215           };
 216 
 217           struct extvtoc {
 218               uint64_t   v_bootinfo[3]; /* info needed by mboot (unsupported) */
 219               uint64_t   v_sanity;      /* to verify vtoc sanity */
 220               uint64_t   v_version;     /* layout version */
 221               char    v_volume[LEN_DKL_VVOL]; /* volume name */
 222               ushort_t   v_sectorsz;    /* sector size in bytes */
 223               ushort_t   v_nparts;      /* number of partitions */
 224               ushort_t   pad[2];
 225               uint64_t   v_reserved[10];
 226               struct extpartition v_part[V_NUMPAR]; /* partition headers */
 227               uint64_t timestamp[V_NUMPAR]; /* partition timestamp */
 228                                             /* (unsupported) */
 229               char    v_asciilabel[LEN_DKL_ASCII];    /* for compatibility */
 230           };
 231 
 232         Partition permissions flags and identification tags are defined the
 233         same as vtoc structure.
 234 
 235      DKIOCEJECT
 236 
 237         If the drive supports removable media, this ioctl(2) requests the disk
 238         drive to eject its disk.
 239 
 240      DKIOCREMOVABLE
 241 
 242         The argument to this ioctl(2) is an integer.  After successful
 243         completion, this ioctl(2) sets that integer to a non-zero value if the
 244         drive in question has removable media.  If the media is not removable,
 245         the integer is set to 0.
 246 
 247      DKIOCHOTPLUGGABLE
 248 
 249         The argument to this ioctl(2) is an integer.  After successful
 250         completion, this ioctl(2) sets that integer to a non-zero value if the
 251         drive in question is hotpluggable.  If the media is not hotpluggable,
 252         the integer is set to 0.
 253 
 254      DKIOCSTATE
 255 
 256         This ioctl(2) blocks until the state of the drive, inserted or
 257         ejected, is changed.  The argument is a pointer to a dkio_state, enum,
 258         whose possible enumerations are listed below.  The initial value
 259         should be either the last reported state of the drive, or DKIO_NONE.
 260         Upon return, the enum pointed to by the argument is updated with the
 261         current state of the drive.
 262 
 263           enum dkio_state {
 264               DKIO_NONE,          /* Return disk's current state */
 265               DKIO_EJECTED,       /* Disk state is 'ejected' */
 266               DKIO_INSERTED       /* Disk state is 'inserted' */
 267           };
 268 
 269      DKIOCLOCK
 270 
 271         For devices with removable media, this ioctl(2) requests the disk
 272         drive to lock the door.
 273 
 274      DKIOCUNLOCK
 275 
 276         For devices with removable media, this ioctl(2) requests the disk
 277         drive to unlock the door.
 278 
 279      DKIOCGMEDIAINFO
 280 
 281         The argument to this ioctl(2) is a pointer to a dk_minfo structure.
 282         The structure indicates the type of media or the command set profile
 283         used by the drive to operate on the media.  The dk_minfo structure
 284         also indicates the logical media block size the drive uses as the
 285         basic unit block size of operation and the raw formatted capacity of
 286         the media in number of logical blocks.
 287 
 288      DKIOCGMEDIAINFOEXT
 289 
 290         The argument to this ioctl(2) is a pointer to a dk_minfo_ext
 291         structure.  The structure indicates the type of media or the command
 292         set profile used by the drive to operate on the media.  The
 293         dk_minfo_ext structure also indicates the logical media block size the
 294         drive uses as the basic unit block size of operation, the raw
 295         formatted capacity of the media in number of logical blocks and the
 296         physical block size of the media.
 297 
 298           /*
 299            * Used for media info or profile info
 300            */
 301           struct dk_minfo {
 302               uint_t dki_media_type;   /* Media type or profile info */
 303               uint_t dki_lbsize;       /* Logical blocksize of media */
 304               diskaddr_t dki_capacity; /* Capacity as # of dki_lbsize blks */
 305           };
 306 
 307           /*
 308            * Used for media info or profile info and physical blocksize
 309            */
 310           struct dk_minfo_ext {
 311               uint_t dki_media_type; /* Media type or profile info */
 312               uint_t dki_lbsize; /* Logical blocksize of media */
 313               diskaddr_t dki_capacity; /* Capacity as # of dki_lbsize blks */
 314               uint_t dki_pbsize; /* Physical blocksize of media */
 315           };
 316 
 317 
 318           /*
 319            * Media types or profiles known
 320            */
 321           #define DK_UNKNOWN         0x00    /* Media inserted - type unknown */
 322 
 323           /*
 324            * SFF 8090 Specification Version 3, media types 0x01 - 0xfffe are
 325            * retained to maintain compatibility with SFF8090.  The following
 326            * define the optical media type.
 327            */
 328           #define DK_MO_ERASABLE     0x03 /* MO Erasable */
 329           #define DK_MO_WRITEONCE    0x04 /* MO Write once */
 330           #define DK_AS_MO           0x05 /* AS MO */
 331           #define DK_CDROM           0x08 /* CDROM */
 332           #define DK_CDR             0x09 /* CD-R */
 333           #define DK_CDRW            0x0A /* CD-RW */
 334           #define DK_DVDROM          0x10 /* DVD-ROM */
 335           #define DK_DVDR            0x11 /* DVD-R */
 336           #define DK_DVDRAM          0x12 /* DVD_RAM or DVD-RW */
 337 
 338           /*
 339            * Media types for other rewritable magnetic media
 340            */
 341           #define DK_FIXED_DISK      0x10001 /* Fixed disk SCSI or otherwise */
 342           #define DK_FLOPPY          0x10002 /* Floppy media */
 343           #define DK_ZIP             0x10003 /* IOMEGA ZIP media */
 344           #define DK_JAZ             0x10004 /* IOMEGA JAZ media */
 345 
 346         If the media exists and the host can obtain a current profile list,
 347         the command succeeds and returns the dk_minfo structure with data
 348         representing that media.
 349 
 350         If there is no media in the drive, the command fails and the host
 351         returns an ENXIO error, indicating that it cannot gather the
 352         information requested.
 353 
 354         If the profile list is not available, the host attempts to identify
 355         the media-type based on the available information.
 356 
 357         If identification is not possible, the host returns media type
 358         DK_UNKNOWN.  See NOTES for blocksize usage and capacity information.
 359 
 360      DKIOCSMBOOT
 361 
 362         The argument is a pointer to struct mboot.
 363 
 364         Copies the mboot information supplied in the argument to the absolute
 365         sector 0 of the device.  Prior to copying the information, this
 366         ioctl(2) performs the following checks on the mboot data:
 367 
 368               o   Ensures that the signature field is set to 0xAA55.
 369 
 370               o   Ensures that partitions do not overlap.
 371 
 372               o   On SPARC platforms, determines if the device is a removable
 373                   media.
 374 
 375         If the above verification fails, errno is set to EINVAL and the
 376         ioctl(2) command fails.
 377 
 378         x86 Platforms -- Upon successful write of mboot, the partition map
 379         structure maintained in the driver is updated.  If the new Solaris
 380         partition is different from the previous one, the internal VTOC table
 381         maintained in the driver is set as follows:
 382 
 383         If _SUNOS_VTOC_8 is defined:
 384 
 385             Partition: 0 Start: 0 Capacity = Capacity of device.
 386             Partition: 2 Start: 0 Capacity = Capacity of device.
 387 
 388         If _SUNOS_VTOC_16 is defined:
 389 
 390             Partition: 2 Start: 0 Size = Size specified in mboot - 2 cylinders.
 391             Partition: 8 Start: 0 Size = Sectors/cylinder.
 392             Partition: 9 Start: Sectors/cylinder  Size = 2 * sectors/cylinder
 393 
 394         To determine if the Solaris partition has changed:
 395 
 396             If either offset or the size of the Solaris partition is different
 397             from the previous one then it shall be deemed to have changed.  In
 398             all other cases, the internal VTOC info remains as before.
 399 
 400         SPARC Platforms -- The VTOC label and mboot both occupy the same
 401         location, namely sector 0.  As a result, following the successful
 402         write of mboot info, the internal VTOC table maintained in the driver
 403         is set as follows:
 404 
 405             Partition: 0  Start: 0  Size = Capacity of device.
 406             Partition: 2  Start: 0  Size = Capacity of device.
 407 
 408         See the NOTES section for usage of DKIOCSMBOOT when modifying Solaris
 409         partitions.
 410 
 411      DKIOCGETVOLCAP
 412 
 413         This ioctl provides information and status of available capabilities.
 414         vc_info is a bitmap and the valid flag values are:
 415 
 416           DKV_ABR_CAP  Capable of application-based recovery
 417           DKV_DMR_CAP  Ability to read specific copy of data when multiple
 418                        copies exist.  For example, in a two way mirror, this
 419                        ioctl is used to read each side of the mirror.
 420 
 421         vc_set is a bitmap and the valid flag values are:
 422 
 423           DKV_ABR_CAP  This flag is set if ABR has been set on a device that
 424                        supports ABR functionality.
 425           DKV_DMR_CAP  Directed read has been enabled.
 426 
 427         These capabilities are not required to be persistent across a system
 428         reboot and their persistence depends upon the implementation.  For
 429         example, if the ABR capability for a DRL mirror simply clears the
 430         dirty-region list and subsequently stops updating this list, there is
 431         no reason for persistence because the VM recovery is a no-op.
 432         Conversely, if the ABR capability is applied to a non-DRL mirror to
 433         indicate that the VM should not perform a full recovery of the mirror
 434         following a system crash, the capability must be persistent so that
 435         the VM know whether or not to perform recovery.
 436 
 437         Return Errors:
 438 
 439           EINVAL   Invalid device for this operation.
 440           ENOTSUP  Functionality that is attempted to be set is not supported.
 441 
 442      DKIOCSETVOLCAP
 443 
 444         This ioctl sets the available capabilities for the device.  If a
 445         capability flag is not set in vc_set, that capability is cleared.
 446 
 447         vc_info flags are ignored.
 448 
 449         vc_set valid flags are:
 450 
 451           DKV_ABR_CAP  Flag to set application-based recovery.  A device can
 452                        successfully support ABR only if it is capable.
 453           DKV_DMR_CAP  Flag to set directed read.
 454 
 455      DKIODMR
 456 
 457         int ioctl(int, DKIODMR, vol_directed_rd *)
 458 
 459         This ioctl allows highly available applications to perform round-robin
 460         reads from the underlying devices of a replicated device.
 461 
 462           vdr_offset     Offset at which the read should occur.
 463           vdr_nbytes     Number of bytes to be read
 464           vdr_bytesread  Number of bytes successfully read by the kernel.
 465           vdr_data       Pointer to a user allocated buffer to return the data
 466                          read
 467           vdr_side       Side to be read.  Initialized to DKV_SIDE_INIT
 468           vdr_side_name  The volume name that has been read.
 469 
 470         Valid vdr_flags are:
 471 
 472           DKV_DMR_NEXT_SIDE  Set by user
 473           DKV_DMR_DONE       Return value
 474           DKV_DMR_ERROR      Return value
 475           DKV_DMR_SUCCESS    Return value
 476           DKV_DMR_SHORT      Return value
 477 
 478         The calling sequence is as follows: The caller sets the vdr_flags to
 479         DK_DMR_NEXT_SIDE and vdr_side to DKV_SIDE_INIT at the start.
 480         Subsequent calls should be made without any changes to these values.
 481         If they are changed the results of the ioctl are indeterminate.
 482 
 483         When DKV_SIDE_INIT is set, the call results in the kernel reading from
 484         the first side.  The kernel updates vdr_side to indicate the side that
 485         was read, and vdr_side_name to contain the name of that side.
 486         vdr_data contains the data that was read.  Therefore to perform a
 487         round-robin read all of the valid sides, there is no need for the
 488         caller to change the contents of vdr_side.
 489 
 490         Subsequent ioctl(2) calls result in reads from the next valid side
 491         until all valid sides have been read.  On success, the kernel sets
 492         DKV_DMR_SUCCESS.  The following table shows the values of vdr_flags
 493         that are returned when an error occurs:
 494 
 495           vda_flags        vdr_side         Notes
 496           DKV_DMR_ERROR    DKV_SIDE_INIT    No valid side to read
 497           DKV_DMR_DONE     Not Init side    All valid sides read
 498           DKV_DMR_SHORT    Any value        Bytes requested cannot be read
 499                                             vdr_bytesread set to bytes
 500                                             actually read
 501         Typical code fragment:
 502 
 503           enable->vc_set |= DKV_ABR_SET;
 504           retval = ioctl(filedes, DKIOSETVOLCAP, enable);
 505           if (retval != EINVAL || retval != ENOTSUP) {
 506                   if (info->vc_set & DKV_DMR_SET) {
 507                           dr->vdr_flags      |= DKV_DMR_NEXT_SIDE;
 508                           dr->vdr_side = DKV_SIDE_INIT;
 509                           dr->vdr_nbytes = 1024;
 510                           dr->vdr_offset = 0xff00;
 511                           do {
 512                                   rval = ioctl(fildes, DKIODMR, dr);
 513                                   if (rval != EINVAL) {
 514                                           /* Process data */
 515                                   }
 516                           } while (rval != EINVAL || dr->vdr_flags &
 517                               (DKV_DMR_DONE | DKV_DMR_ERROR | DKV_DMR_SHORT)
 518                   }
 519           }
 520 
 521      DKIOCFREE
 522 
 523         The argument is a pointer to a dkioc_free_list_t structure (described
 524         below).  The structure consists of a header followed by one or more
 525         dkioc_free_list_ext_t strctures (described below) that list the
 526         extents that the device should free.
 527 
 528           typedef struct dkioc_free_list_ext_s {
 529                   uint64_t                dfle_start;
 530                   uint64_t                dfle_length;
 531           } dkioc_free_list_ext_t;
 532 
 533           typedef struct dkioc_free_list_s {
 534                   uint64_t                dfl_flags;
 535                   uint64_t                dfl_num_exts;
 536                   uint64_t                dfl_offset;
 537                   dkioc_free_list_ext_t   dfl_exts[1];
 538           } dkioc_free_list_t;
 539 
 540         The dfle_start, dfle_length, and dfl_offset fields are in units of
 541         bytes (not blocks).
 542 
 543         The values for dfl_flags are:
 544 
 545         DF_WAIT_SYNC  Wait for the device to complete freeing the space before
 546                       returning.
 547 
 548         The dfl_num_exts field indicates the number of dkioc_free_list_ext_t
 549         structures follow the dkioc_free_list_t structure (including the first
 550         entry in dfl_exts).  There must be at least one dkioc_free_list_ext_t
 551         in the ioctl(2) request (i.e.  dfl_num_exts must be >= 1).
 552 
 553         The dfl_offset field is added to all of the values of dfle_start when
 554         processed by the device.
 555 
 556         The dfl_exts field contains the first extent to free, immediately
 557         followed by any additional dkioc_free_list_ext_t structures if there
 558         are more than one extent to free.
 559 
 560         The DFL_SZ(num_exts) macro can be used to calculate the amount of
 561         memory required to hold num_exts extents.
 562 
 563      DKIOC_CANFREE
 564         The argument is a pointer to an int that is populated by the ioctl(2)
 565         request.  Upon a successful return, if a non-zero value has been set
 566         in the int parameter, it indicates that the device supports the
 567         DKIOCFREE ioctl(2).  If the int parameter has been set to zero, the
 568         DKIOCFREE ioctl(2) is not supported by the device.
 569 
 570    RETURN VALUES
 571      Upon successful completion, the value returned is 0.  Otherwise, -1 is
 572      returned and errno is set to indicate the error.
 573 
 574    x86 Only
 575      The following ioctl(2) requests set and/or retrieve the current disk
 576      controller, partitions, or geometry information on the x86 architecture.
 577 
 578      DKIOCG_PHYGEOM
 579 
 580         The argument is a pointer to a dk_geom structure (described below).
 581         This ioctl(2) gets the driver's notion of the physical geometry of the
 582         disk drive.  It is functionally identical to the DKIOCGGEOM ioctl(2).
 583 
 584      DKIOCG_VIRTGEOM
 585 
 586         The argument is a pointer to a dk_geom structure (described below).
 587         This ioctl(2) gets the controller's (and hence the driver's) notion of
 588         the virtual geometry of the disk drive.  Virtual geometry is a view of
 589         the disk geometry maintained by the firmware in a host bus adapter or
 590         disk controller.  If the disk is larger than 8 Gbytes, this ioctl
 591         fails because a CHS-based geometry is not relevant or useful for this
 592         drive.
 593 
 594           /*
 595            * Definition of a disk's geometry
 596            */
 597           struct dk_geom {
 598               unsigned shor    dkg_ncyl;   /* # of data cylinders */
 599               unsigned shor    dkg_acyl;   /* # of alternate cylinders */
 600               unsigned short   dkg_bcyl;   /* cyl offset (for fixed head */
 601                                            /* area) */
 602               unsigned short   dkg_nhead;  /* # of heads */
 603               unsigned short   dkg_obs1;   /* obsolete */
 604               unsigned short   dkg_nsect;  /* # of sectors per track */
 605               unsigned short   dkg_intrlv; /* interleave factor */
 606               unsigned short   dkg_obs2;   /* obsolete */
 607               unsigned short   dkg_obs3;   /* obsolete */
 608               unsigned short   dkg_apc;    /* alternates per cylinder */
 609                                            /* (SCSI only) */
 610               unsigned short   dkg_rpm;    /* revolutions per min */
 611               unsigned short   dkg_pcyl;   /* # of physical cylinders */
 612               unsigned short   dkg_write_reinstruct; /* # sectors to skip, */
 613                                                      /* writes */
 614               unsigned short   dkg_read_reinstruct;  /* # sectors to skip ,*/
 615                                                      /* reads */
 616               unsigned short   dkg_extra[7]; /* for compatible expansion */
 617           };
 618 
 619      DKIOCADDBAD
 620 
 621         This ioctl(2) forces the driver to re-examine the alternates slice and
 622         rebuild the internal bad block map accordingly.  It should be used
 623         whenever the alternates slice is changed by any method other than the
 624         addbadsec(1M) or format(1M) utilities.  DKIOCADDBAD can only be used
 625         for software remapping on IDE drives; SCSI drives use hardware
 626         remapping of alternate sectors.
 627 
 628      DKIOCPARTINFO
 629 
 630         The argument is a pointer to a part_info structure (described below).
 631         This ioctl(2) gets the driver's notion of the size and extent of the
 632         partition or slice indicated by the file descriptor argument.
 633 
 634           /*
 635            * Used by applications to get partition or slice information
 636            */
 637           struct part_info {
 638               daddr_t    p_start;
 639               int        p_length;
 640           };
 641 
 642      DKIOCEXTPARTINFO
 643 
 644         The argument is a pointer to an extpart_info structure (described
 645         below).  This ioctl gets the driver's notion of the size and extent of
 646         the partition or slice indicated by the file descriptor argument.  On
 647         disks larger than 1TB, this ioctl must be used instead of
 648         DKIOCPARTINFO.
 649 
 650           /*
 651            * Used by applications to get partition or slice information
 652            */
 653           struct extpart_info {
 654               diskkaddr_t      p_start;
 655               diskaddr_t       p_length;
 656           };
 657 
 658      DKIOCSETEXTPART
 659 
 660         This ioctl is used to update the in-memory copy of the logical drive
 661         information maintained by the driver.  The ioctl takes no arguments.
 662         It causes a re-read of the partition information and recreation of
 663         minor nodes if required.  Prior to updating the data structures, the
 664         ioctl ensures that the partitions do not overlap.  Device nodes are
 665         created only for valid partition entries.  If there is any change in
 666         the partition offset, size or ID from the previous read, the partition
 667         is deemed to have been changed and hence the device nodes are
 668         recreated.  Any modification to any of the logical partitions results
 669         in the recreation of all logical device nodes.
 670 
 671 SEE ALSO
 672      addbadsec(1M), fdisk(1M), format(1M), ioctl(2), cmdk(7D), sd(7D),
 673      cdio(7I), fdio(7I), hdio(7I)
 674 
 675 NOTES
 676      Blocksize information provided in DKIOCGMEDIAINFO is the size (in bytes)
 677      of the device's basic unit of operation and can differ from the blocksize
 678      that the Solaris operating environment exports to the user.  Capacity
 679      information provided in the DKIOCGMEDIAINFO are for reference only and
 680      you are advised to use the values returned by DKIOCGGEOM or other
 681      appropriate ioctl(2) for accessing data using the standard interfaces.
 682 
 683      For x86 only: If the DKIOCSMBOOT command is used to modify the Solaris
 684      partitions, the VTOC information should also be set appropriately to
 685      reflect the changes to partition.  Failure to do so leads to unexpected
 686      results when the device is closed and reopened fresh at a later time.
 687      This is because a default VTOC is assumed by driver when a Solaris
 688      partition is changed.  The default VTOC persists until the ioctl
 689      DKIOCSVTOC is called to modify VTOC or the device is closed and reopened.
 690      At that point, the old valid VTOC is read from the disk if it is still
 691      available.
 692 
 693 illumos                        February 14, 2020                       illumos