dkio(7I)
NAME
dkio - disk control operations
SYNOPSIS
#include <sys/dkio.h>
#include <sys/vtoc.h>
DESCRIPTION
Disk drivers support a set of ioctl(2) requests for disk
controller, geometry, and partition information. Basic to
these ioctl() requests are the definitions in <sys/dkio.h>.
IOCTLS
The following ioctl() requests set and/or retrieve the
current disk controller, partitions, or geometry information
on all architectures:
DKIOCINFO
The argument is a pointer to a dk_cinfo structure
(described below). This structure tells the
controller-type and attributes regarding bad-block
processing done on the controller.
/*
* Structures and definitions for disk I/O control commands
*/
#define DK_DEVLEN 16 /* device name max length, */
/* including unit # and NULL */
/* Used for controller info */
struct dk_cinfo {
char dki_cname[DK_DEVLEN]; /* controller name */
/*(no unit #)*/
ushort_t dki_ctype; /* controller type */
ushort_t dki_flags; /* flags */
ushort_t dki_cnum; /* controller number */
uint_t dki_addr; /* controller address */
uint_t dki_space; /* controller bus type */
uint_t dki_prio; /* interrupt priority */
uint_t dki_vec; /* interrupt vector */
char dki_dname[DK_DEVLEN]; /* drive name (no unit #) */
uint_t dki_unit; /* unit number */
uint_t dki_slave; /* slave number */
ushort_t dki_partition; /* partition number */
ushort_t dki_maxtransfer; /* maximum transfer size */
/* in DEV_BSIZE */
};
/*
* Controller types
*/
#define DKC_UNKNOWN 0
#define DKC_CDROM 1 /* CD-ROM, SCSI or other */
#define DKC_WDC2880 2
#define DKC_XXX_0 3 /* unassigned */
#define DKC_XXX_1 4 /* unassigned */
#define DKC_DSD5215 5
#define DKC_ACB4000 7
#define DKC_XXX_2 9 /* unassigned */
#define DKC_NCRFLOPPY 10
#define DKC_SMSFLOPPY 12
#define DKC_SCSI_CCS 13 /* SCSI CCS compatible */
#define DKC_INTEL82072 14 /* native floppy chip */
#define DKC_MD 16 /* meta-disk (virtual-disk) */
/* driver */
#define DKC_INTEL82077 19 /* 82077 floppy disk */
/* controller */
#define DKC_DIRECT 20 /* Intel direct attached */
/* device (IDE) */
#define DKC_PCMCIA_MEM 21 /* PCMCIA memory disk-like */
/* type */
#define DKC_PCMCIA_ATA 22 /* PCMCIA AT Attached type */
/*
* Sun reserves up through 1023
*/
#define DKC_CUSTOMER_BASE 1024
/*
* Flags
*/
#define DKI_BAD144 0x01 /* use DEC std 144 */
/* bad sector fwding */
#define DKI_MAPTRK 0x02 /* controller does */
/* track mapping */
#define DKI_FMTTRK 0x04 /* formats only full
/* track at a time*/
#define DKI_FMTVOL 0x08 /* formats only full */
/* volume at a time*/
#define DKI_FMTCYL 0x10 /* formats only full */
/* cylinders at a time*/
#define DKI_HEXUNIT 0x20 /* unit number printed as */
/* 3 hexdigits */
#define DKI_PCMCIA_PFD 0x40 /* PCMCIA pseudo-floppy */
/* memory card */
DKIOCGAPART
The argument is a pointer to a dk_allmap structure
(described below). This ioctl() gets the controller's
notion of the current partition table for disk drive.
DKIOCSAPART
The argument is a pointer to a dk_allmap structure
(described below). This ioctl() sets the controller's
notion of the partition table without changing the
disk itself.
/*
* Partition map (part of dk_label)
*/ struct dk_map {
daddr_t dkl_cylno; /* starting cylinder */
daddr_t dkl_nblk; /* number of blocks */
};
/*
* Used for all partitions
*/
struct dk_map {
struct dk_allmap {
struct dk_map dka_map[NDKMAP];
};
DKIOCGGEOM
The argument is a pointer to a dk_geom structure
(described below). This ioctl() gets the controller's
notion of the current geometry of the disk drive.
DKIOCSGEOM
The argument is a pointer to a dk_geom structure
(described below). This ioctl() sets the controller's
notion of the geometry without changing the disk
itself.
DKIOCGVTOC
The argument is a pointer to a vtoc structure
(described below). This ioctl() returns the device's
current volume table of contents (VTOC.)
DKIOCSVTOC
The argument is a pointer to a vtoc structure
(described below). This ioctl() changes the VTOC asso-
ciated with the device.
struct partition {
ushort_t p_tag; /* ID tag of partition */
ushort_t p_flag; /* permission flags */
daddr_t p_start; /* start sector of partition */
long p_size; /* # of blocks in partition */
};
If DKIOCSVTOC is used with a floppy diskette, the p_start
field must be the first sector of a cylinder. To compute the
number of sectors per cylinder, multiply the number of heads
by the number of sectors per track.
struct vtoc {
unsigned long v_bootinfo[3]; /* info needed by mboot
/* (unsupported)*/
unsigned long v_sanity; /* to verify vtoc sanity */
unsigned long v_version; /* layout version */
char v_volume[LEN_DKL_VVOL]; /* volume name */
ushort_t v_sectorsz;
sector size in bytes*/
ushort_t v_nparts;
number of partitions*/
unsigned long v_reserved[10]; /* free space */
struct partition v_part[V_NUMPAR]; /* partition headers*/
time_t timestamp[V_NUMPAR]; /* partition timestamp
/* (unsupported)*/
char v_asciilabel[LEN_DKL_ASCII]; /* compatibility */
};
/*
* Partition permission flags
*/
#define V_UNMNT 0x01 /* Unmountable partition */
#define V_RONLY 0x10 /* Read only */
/*
* Partition identification tags
*/
#define V_UNASSIGNED 0x00 /* unassigned partition */
#define V_BOOT 0x01 /* Boot partition */
#define V_ROOT 0x02 /* Root filesystem */
#define V_SWAP 0x03 /* Swap filesystem */
#define V_USR 0x04 /* Usr filesystem */
#define V_BACKUP 0x05 /* full disk */
#define V_VAR 0x07 /* Var partition */
#define V_HOME 0x08 /* Home partition */
#define V_ALTSCTR 0x09 /* Alternate sector partition */
DKIOCEJECT
If the drive supports removable media, this ioctl()
requests the disk drive to eject its disk.
DKIOCREMOVABLE
The argument to this ioctl() is an integer. After suc-
cessful completion, this ioctl() sets that integer to
a non-zero value if the drive in question has remov-
able media. If the media is not removable, that
integer is set to 0.
DKIOCSTATE
This ioctl() blocks until the state of the drive,
inserted or ejected, is changed. The argument is a
pointer to a dkio_state, enum, whose possible enumera-
tions are listed below. The initial value should be
either the last reported state of the drive, or
DKIO_NONE. Upon return, the enum pointed to by the
argument is updated with the current state of the
drive.
enum dkio_state {
DKIO_NONE, /* Return disk's current state */
DKIO_EJECTED, /* Disk state is 'ejected' */
DKIO_INSERTED /* Disk state is 'inserted' */
};
DKIOCLOCK
For devices with removable media, this ioctl()
requests the disk drive to lock the door.
DKIOCUNLOCK
For devices with removable media, this ioctl()
requests the disk drive to unlock the door.
DKIOCGMEDIAINFO
The argument to this ioctl() is a pointer to a
dk_minfo structure. The structure indicates the type
of media or the command set profile used by the drive
to operate on the media. The dk_minfo structure also
indicates the logical media blocksize the drive uses
as the basic unit blocksize of operation and the raw
formatted capacity of the media in number of logical
blocks.
/*
* Used for media info or profile info
*/
struct dk_minfo {
uint_t dki_media_type; /* Media type or profile info */
uint_t dki_lbsize; /* Logical blocksize of media */
diskaddr_t dki_capacity; /* Capacity as # of dki_lbsize blks */
};
/*
* Media types or profiles known
*/
#define DK_UNKNOWN 0x00 /* Media inserted - type unknown */
/*
* SFF 8090 Specification Version 3, media types 0x01 - 0xfffe are retained to
* maintain compatibility with SFF8090. The following define the
* optical media type.
*/
#define DK_MO_ERASABLE 0x03 /* MO Erasable */
#define DK_MO_WRITEONCE 0x04 /* MO Write once */
#define DK_AS_MO 0x05 /* AS MO */
#define DK_CDROM 0x08 /* CDROM */
#define DK_CDR 0x09 /* CD-R */
#define DK_CDRW 0x0A /* CD-RW */
#define DK_DVDROM 0x10 /* DVD-ROM */
#define DK_DVDR 0x11 /* DVD-R */
#define DK_DVDRAM 0x12 /* DVD_RAM or DVD-RW */
/*
* Media types for other rewritable magnetic media
*/
#define DK_FIXED_DISK 0x10001 /* Fixed disk SCSI or otherwise */
#define DK_FLOPPY 0x10002 /* Floppy media */
#define DK_ZIP 0x10003 /* IOMEGA ZIP media */
#define DK_JAZ 0x10004 /* IOMEGA JAZ media */
If the media exists and the host can obtain a current pro-
file list, the command succeeds and returns the dk_minfo
structure with data representing that media.
If there is no media in the drive, the command fails and the
host returns an ENXIO error, indicating that it cannot
gather the information requested.
If the profile list is not available, the host attempts to
identify the media-type based on the available information.
If identification is not possible, the host returns media
type DK_UNKNOWN. See NOTES for blocksize usage and capacity
information.
DKIOCSMBOOT
The argument is a pointer to struct mboot.
Copies the mboot information supplied in the argument
to the absolute sector 0 of the device. Prior to copy-
ing the information, this ioctl() performs the follow-
ing checks on the mboot data:
o Ensures that the signature field is set to
0xAA55.
o Ensures that partitions do not overlap.
o On SPARC platforms, determines if the device is
a removable media.
If the above verification fails, errno is set to EINVAL and
the ioctl() command fails.
x86 Platforms - Upon successful write of mboot, the parti-
tion map structure maintained in the driver is updated. If
the new Solaris partition is different from the previous
one, the internal VTOC table maintained in the driver is set
as follows:
If _SUNOS_VTOC_8 is defined:
Partition: 0. Start: 0. Capacity = Capacity of device.
Partition: 2. Start: 0. Capacity = Capacity of device.
If _SUNOS_VTOC_16 is defined:
Partition: 2. Start: 0. Size = Size specified in mboot - 2
cylinders.
Partition: 8. Start: 0. Size = Sectors/cylinder.
Partition: 9. Start: Sectors/cylinder. Size = 2 *
sectors/cylinder
To determine if the Solaris partition has changed:
If either offset or the size of the Solaris partition is
different from the previous one then it shall be deemed to
have changed. In all other cases, the internal VTOC info
remains as before.
SPARC Platforms - The VTOC label and mboot both occupy the
same location, namely sector 0. As a result, following the
successful write of mboot info, the internal VTOC table
maintained in the driver is set as follows:
Partition: 0. Start: 0. Size = Capacity of device.
Partition: 2. Start: 0. Size = Capacity of device.
See the NOTES section for usage of DKIOCSMBOOT when
modifying Solaris partitions.
DKIOCGETVOLCAP
This ioctl provides information and status of avail-
able capabilities.
vc_info is a bitmap and the valid flag values are:
DKV_ABR_CAP - Capable of application-based recovery
DKV_DMR_CAP - Ability to read specific copy of data when
multiple copies exist. For example, in a two
way mirror, this ioctl is used to read each
side of the mirror.
vc_set is a bitmap and the valid flag values are:
DKV_ABR_CAP - This flag is set if ABR has been set on a device
that supports ABR functionality.
DKV_DMR_CAP - Directed read has been enabled.
Note: These capabilities are not required to be persistent
across a system reboot and their persistence depends upon
the implementation. For example, if the ABR capability for a
DRL mirror simply clears the dirty-region list and sub-
seqently stops updating this list, there is no reason for
persistence because the VM recovery is a no-op. Conversely,
if the ABR capability is applied to a non-DRL mirror to
indicate that the VM should not perform a full recovery of
the mirror following a system crash, the capability must be
persistent so that the VM know whether or not to perform
recovery.
Return Errors:
EINVAL - Invalid device for this operation.
ENOTSUP - Functionality that is attempted to be set is
not supported.
DKIOCSETVOLCAP
This ioctl sets the available capabilities for the
device. If a capability flag is not set in vc_set,
that capability is cleared.
vc_info flags are ignored
vc_set valid flags are:
DKV_ABR_CAP - Flag to set application-based recovery. A device can
successfully support ABR only if it is capable.
DKV_DMR_CAP - Flag to set directed read.
int
ioctl(int , DKIODMR, vol_directed_rd *);
DKIODMR
This ioctl allows highly available applications to
perform round-robin reads from the underlying devices
of a replicated device.
vdr_offset - offset at which the read should occur.
vdr_nbytes - number of bytes to be read
vdr_bytesread - number of bytes successfully read by the kernel.
vdr_data - pointer to a user allocated buffer to return the data
read
vdr_side - side to be read. Initialized to DKV_SIDE_INIT
vdr_side_name - The volume name that has been read.
Valid vdr_flags are:
DKV_DMR_NEXT_SIDE (set by user)
DKV_DMR_DONE (return value)
DKV_DMR_ERROR (return value)
DKV_DMR_SUCCESS(return value)
DKV_DMR_SHORT(return value)
The calling sequence is as follows: The caller sets the
vdr_flags to DK_DMR_NEXT_SIDE and vdr_side to DKV_SIDE_INIT
at the start. Subsequent calls should be made without any
changes to these values. If they are changed the results of
the ioctl are indeterminate.
When DKV_SIDE_INIT is set, the call results in the kernel
reading from the first side. The kernel updates vdr_side to
indicate the side that was read, and vdr_side_name to con-
tain the name of that side. vdr_data contains the data that
was read. Therefore to perform a round-robin read all of the
valid sides, there is no need for the caller to change the
contents of vdr_side.
Subsequent ioctl calls result in reads from the next
valid side until all valid sides have been read. On
success, the kernel sets DKV_DMR_SUCCESS. The following
table shows the values of vdr_flags that are returned
when an error occurs:
vdr_flags | vdr_side | Notes
-------------|-------------------|----------------------------
DKV_DMR_ERROR| DKV_SIDE_INIT | No valid side to read
DKV_DMR_DONE | Not Init side | All valid sides read
DKV_DMR_SHORT| Any value | Bytes requested cannot
be read. vdr_bytesread
set to bytes actually
read.
Typical code fragment:
enable->vc_set |= DKV_ABR_SET;
retval = ioctl(filedes, DKIOSETVOLCAP, enable);
if (retval != EINVAL || retval != ENOTSUP) {
if (info->vc_set & DKV_DMR_SET) {
dr->vdr_flags |= DKV_DMR_NEXT_SIDE;
dr->vdr_side = DKV_SIDE_INIT;
dr->vdr_nbytes = 1024;
dr->vdr_offset = 0xff00;
do {
rval =ioctl(fildes, DKIODMR, dr);
if (rval != EINVAL) {
/* Process data */
}
} while (rval != EINVAL || dr->vdr_flags &
(DKV_DMR_DONE | DKV_DMR_ERROR | DKV_DMR_SHORT)
}
}
RETURN VALUES
Upon successful completion, the value returned is 0. Other-
wise, -1 is returned and errno is set to indicate the
error.
x86 Only
The following ioctl() requests set and/or retrieve the
current disk controller, partitions, or geometry information
on the x86 architecture.
DKIOCG_PHYGEOM
The argument is a pointer to a dk_geom structure
(described below). This ioctl() gets the driver's
notion of the physical geometry of the disk drive. It
is functionally identical to the DKIOCGGEOM ioctl().
DKIOCG_VIRTGEOM
The argument is a pointer to a dk_geom structure
(described below). This ioctl() gets the controller's
(and hence the driver's) notion of the virtual
geometry of the disk drive. Virtual geometry is a view
of the disk geometry maintained by the firmware in a
host bus adapter or disk controller. If the disk is
larger than 8 Gbytes, this ioctl fails because a CHS-
based geometry is not relevant or useful for this
drive.
/*
* Definition of a disk's geometry
*/
*/struct dk_geom {
unsigned shor dkg_ncyl; /* # of data cylinders */
unsigned shor dkg_acyl; /* # of alternate cylinders */
unsigned short dkg_bcyl; /* cyl offset (for fixed head area) */
unsigned short dkg_nhead; /* # of heads */
unsigned short dkg_obs1; /* obsolete */
unsigned short dkg_nsect; /* # of sectors per track*/
unsigned short dkg_intrlv; /* interleave factor */
unsigned short dkg_obs2; /* obsolete */
unsigned short dkg_obs3; /* obsolete */
unsigned short dkg_apc; /* alternates per cylinder */
/* (SCSI only) */
unsigned short dkg_rpm; /* revolutions per min*/
unsigned short dkg_pcyl; /* # of physical cylinders */
unsigned short dkg_write_reinstruct; /* # sectors to skip, writes*/
unsigned short dkg_read_reinstruct; /* # sectors to skip, reads*/
unsigned short dkg_extra[7]; /* for compatible expansion*/
};
DKIOCADDBAD
This ioctl() forces the driver to re-examine the
alternates slice and rebuild the internal bad block
map accordingly. It should be used whenever the alter-
nates slice is changed by any method other than the
addbadsec(1M) or format(1M) utilities. DKIOCADDBAD can
only be used for software remapping on IDE drives;
SCSI drives use hardware remapping of alternate sec-
tors.
DKIOCPARTINFO
The argument is a pointer to a part_info structure
(described below). This ioctl() gets the driver's
notion of the size and extent of the partition or
slice indicated by the file descriptor argument.
/*
* Used by applications to get partition or slice information
*/
struct part_info {
daddr_t p_start;
int p_length;
};
SEE ALSO
fdisk(1M), format(1M), ioctl(2), sd(7D), cdio(7I),
fdio(7I), hdio(7I)
x86 Only
addbadsec(1M), cmdk(7D)
NOTES
Blocksize information provided in DKIOCGMEDIAINFO is the
size (in bytes) of the device's basic unit of operation and
may differ from the blocksize that the Solaris operating
environment exports to the user. Capacity information pro-
vided in the DKIOCGMEDIAINFO are for reference only and you
are advised to use the values returned by DKIOCGGEOM or
other appropriate ioctl for accessing data using the stan-
dard interfaces.
For X86 only: If the DKIOCSMBOOT command is used to modify
the Solaris partitions, the VTOC information should also be
set appropriately to reflect the the changes to partition.
Failure to do so will lead to unexpected results when the
device is closed and re-opened fresh at a later time. This
is because a default VTOC is assumed by driver when a
Solaris partition is changed. The default VTOC will persist
until the ioctl DKIOCSVTOC is called to modify VTOC or the
device is closed and re-opened. At that point, the old valid
VTOC will be read from the disk if it is still available.
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