--- /dev/null
+ Summary of CDROM ioctl calls.
+ ============================
+
+ Edward A. Falk <efalk@google.com>
+
+ November, 2004
+
+This document attempts to describe the ioctl(2) calls supported by
+the CDROM layer. These are by-and-large implemented (as of Linux 2.6)
+in drivers/cdrom/cdrom.c and drivers/block/scsi_ioctl.c
+
+ioctl values are listed in <linux/cdrom.h>. As of this writing, they
+are as follows:
+
+ CDROMPAUSE Pause Audio Operation
+ CDROMRESUME Resume paused Audio Operation
+ CDROMPLAYMSF Play Audio MSF (struct cdrom_msf)
+ CDROMPLAYTRKIND Play Audio Track/index (struct cdrom_ti)
+ CDROMREADTOCHDR Read TOC header (struct cdrom_tochdr)
+ CDROMREADTOCENTRY Read TOC entry (struct cdrom_tocentry)
+ CDROMSTOP Stop the cdrom drive
+ CDROMSTART Start the cdrom drive
+ CDROMEJECT Ejects the cdrom media
+ CDROMVOLCTRL Control output volume (struct cdrom_volctrl)
+ CDROMSUBCHNL Read subchannel data (struct cdrom_subchnl)
+ CDROMREADMODE2 Read CDROM mode 2 data (2336 Bytes)
+ (struct cdrom_read)
+ CDROMREADMODE1 Read CDROM mode 1 data (2048 Bytes)
+ (struct cdrom_read)
+ CDROMREADAUDIO (struct cdrom_read_audio)
+ CDROMEJECT_SW enable(1)/disable(0) auto-ejecting
+ CDROMMULTISESSION Obtain the start-of-last-session
+ address of multi session disks
+ (struct cdrom_multisession)
+ CDROM_GET_MCN Obtain the "Universal Product Code"
+ if available (struct cdrom_mcn)
+ CDROM_GET_UPC Deprecated, use CDROM_GET_MCN instead.
+ CDROMRESET hard-reset the drive
+ CDROMVOLREAD Get the drive's volume setting
+ (struct cdrom_volctrl)
+ CDROMREADRAW read data in raw mode (2352 Bytes)
+ (struct cdrom_read)
+ CDROMREADCOOKED read data in cooked mode
+ CDROMSEEK seek msf address
+ CDROMPLAYBLK scsi-cd only, (struct cdrom_blk)
+ CDROMREADALL read all 2646 bytes
+ CDROMGETSPINDOWN return 4-bit spindown value
+ CDROMSETSPINDOWN set 4-bit spindown value
+ CDROMCLOSETRAY pendant of CDROMEJECT
+ CDROM_SET_OPTIONS Set behavior options
+ CDROM_CLEAR_OPTIONS Clear behavior options
+ CDROM_SELECT_SPEED Set the CD-ROM speed
+ CDROM_SELECT_DISC Select disc (for juke-boxes)
+ CDROM_MEDIA_CHANGED Check is media changed
+ CDROM_DRIVE_STATUS Get tray position, etc.
+ CDROM_DISC_STATUS Get disc type, etc.
+ CDROM_CHANGER_NSLOTS Get number of slots
+ CDROM_LOCKDOOR lock or unlock door
+ CDROM_DEBUG Turn debug messages on/off
+ CDROM_GET_CAPABILITY get capabilities
+ CDROMAUDIOBUFSIZ set the audio buffer size
+ DVD_READ_STRUCT Read structure
+ DVD_WRITE_STRUCT Write structure
+ DVD_AUTH Authentication
+ CDROM_SEND_PACKET send a packet to the drive
+ CDROM_NEXT_WRITABLE get next writable block
+ CDROM_LAST_WRITTEN get last block written on disc
+
+
+The information that follows was determined from reading kernel source
+code. It is likely that some corrections will be made over time.
+
+
+
+
+
+
+
+General:
+
+ Unless otherwise specified, all ioctl calls return 0 on success
+ and -1 with errno set to an appropriate value on error. (Some
+ ioctls return non-negative data values.)
+
+ Unless otherwise specified, all ioctl calls return -1 and set
+ errno to EFAULT on a failed attempt to copy data to or from user
+ address space.
+
+ Individual drivers may return error codes not listed here.
+
+ Unless otherwise specified, all data structures and constants
+ are defined in <linux/cdrom.h>
+
+
+
+
+CDROMPAUSE Pause Audio Operation
+
+ usage:
+
+ ioctl(fd, CDROMPAUSE, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+
+CDROMRESUME Resume paused Audio Operation
+
+ usage:
+
+ ioctl(fd, CDROMRESUME, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+
+CDROMPLAYMSF Play Audio MSF (struct cdrom_msf)
+
+ usage:
+
+ struct cdrom_msf msf;
+ ioctl(fd, CDROMPLAYMSF, &msf);
+
+ inputs:
+ cdrom_msf structure, describing a segment of music to play
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+ notes:
+ MSF stands for minutes-seconds-frames
+ LBA stands for logical block address
+
+ Segment is described as start and end times, where each time
+ is described as minutes:seconds:frames. A frame is 1/75 of
+ a second.
+
+
+CDROMPLAYTRKIND Play Audio Track/index (struct cdrom_ti)
+
+ usage:
+
+ struct cdrom_ti ti;
+ ioctl(fd, CDROMPLAYTRKIND, &ti);
+
+ inputs:
+ cdrom_ti structure, describing a segment of music to play
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+ notes:
+ Segment is described as start and end times, where each time
+ is described as a track and an index.
+
+
+
+CDROMREADTOCHDR Read TOC header (struct cdrom_tochdr)
+
+ usage:
+
+ cdrom_tochdr header;
+ ioctl(fd, CDROMREADTOCHDR, &header);
+
+ inputs:
+ cdrom_tochdr structure
+
+ outputs:
+ cdrom_tochdr structure
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+
+
+CDROMREADTOCENTRY Read TOC entry (struct cdrom_tocentry)
+
+ usage:
+
+ struct cdrom_tocentry entry;
+ ioctl(fd, CDROMREADTOCENTRY, &entry);
+
+ inputs:
+ cdrom_tocentry structure
+
+ outputs:
+ cdrom_tocentry structure
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+ EINVAL entry.cdte_format not CDROM_MSF or CDROM_LBA
+ EINVAL requested track out of bounds
+ EIO I/O error reading TOC
+
+ notes:
+ TOC stands for Table Of Contents
+ MSF stands for minutes-seconds-frames
+ LBA stands for logical block address
+
+
+
+CDROMSTOP Stop the cdrom drive
+
+ usage:
+
+ ioctl(fd, CDROMSTOP, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+ notes:
+ Exact interpretation of this ioctl depends on the device,
+ but most seem to spin the drive down.
+
+
+CDROMSTART Start the cdrom drive
+
+ usage:
+
+ ioctl(fd, CDROMSTART, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+ notes:
+ Exact interpretation of this ioctl depends on the device,
+ but most seem to spin the drive up and/or close the tray.
+ Other devices ignore the ioctl completely.
+
+
+CDROMEJECT Ejects the cdrom media
+
+ usage:
+
+ ioctl(fd, CDROMEJECT, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error returns:
+ ENOSYS cd drive not capable of ejecting
+ EBUSY other processes are accessing drive, or door is locked
+
+ notes:
+ See CDROM_LOCKDOOR, below.
+
+
+
+CDROMCLOSETRAY pendant of CDROMEJECT
+
+ usage:
+
+ ioctl(fd, CDROMCLOSETRAY, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error returns:
+ ENOSYS cd drive not capable of closing the tray
+ EBUSY other processes are accessing drive, or door is locked
+
+ notes:
+ See CDROM_LOCKDOOR, below.
+
+
+
+CDROMVOLCTRL Control output volume (struct cdrom_volctrl)
+
+ usage:
+
+ struct cdrom_volctrl volume;
+ ioctl(fd, CDROMVOLCTRL, &volume);
+
+ inputs:
+ cdrom_volctrl structure containing volumes for up to 4
+ channels.
+
+ outputs: none
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+
+
+CDROMVOLREAD Get the drive's volume setting
+ (struct cdrom_volctrl)
+
+ usage:
+
+ struct cdrom_volctrl volume;
+ ioctl(fd, CDROMVOLREAD, &volume);
+
+ inputs: none
+
+ outputs:
+ The current volume settings.
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+
+
+
+CDROMSUBCHNL Read subchannel data (struct cdrom_subchnl)
+
+ usage:
+
+ struct cdrom_subchnl q;
+ ioctl(fd, CDROMSUBCHNL, &q);
+
+ inputs:
+ cdrom_subchnl structure
+
+ outputs:
+ cdrom_subchnl structure
+
+ error return:
+ ENOSYS cd drive not audio-capable.
+ EINVAL format not CDROM_MSF or CDROM_LBA
+
+ notes:
+ Format is converted to CDROM_MSF on return
+
+
+
+CDROMREADRAW read data in raw mode (2352 Bytes)
+ (struct cdrom_read)
+
+ usage:
+
+ union {
+ struct cdrom_msf msf; /* input */
+ char buffer[CD_FRAMESIZE_RAW]; /* return */
+ } arg;
+ ioctl(fd, CDROMREADRAW, &arg);
+
+ inputs:
+ cdrom_msf structure indicating an address to read.
+ Only the start values are significant.
+
+ outputs:
+ Data written to address provided by user.
+
+ error return:
+ EINVAL address less than 0, or msf less than 0:2:0
+ ENOMEM out of memory
+
+ notes:
+ As of 2.6.8.1, comments in <linux/cdrom.h> indicate that this
+ ioctl accepts a cdrom_read structure, but actual source code
+ reads a cdrom_msf structure and writes a buffer of data to
+ the same address.
+
+ MSF values are converted to LBA values via this formula:
+
+ lba = (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_MSF_OFFSET;
+
+
+
+
+CDROMREADMODE1 Read CDROM mode 1 data (2048 Bytes)
+ (struct cdrom_read)
+
+ notes:
+ Identical to CDROMREADRAW except that block size is
+ CD_FRAMESIZE (2048) bytes
+
+
+
+CDROMREADMODE2 Read CDROM mode 2 data (2336 Bytes)
+ (struct cdrom_read)
+
+ notes:
+ Identical to CDROMREADRAW except that block size is
+ CD_FRAMESIZE_RAW0 (2336) bytes
+
+
+
+CDROMREADAUDIO (struct cdrom_read_audio)
+
+ usage:
+
+ struct cdrom_read_audio ra;
+ ioctl(fd, CDROMREADAUDIO, &ra);
+
+ inputs:
+ cdrom_read_audio structure containing read start
+ point and length
+
+ outputs:
+ audio data, returned to buffer indicated by ra
+
+ error return:
+ EINVAL format not CDROM_MSF or CDROM_LBA
+ EINVAL nframes not in range [1 75]
+ ENXIO drive has no queue (probably means invalid fd)
+ ENOMEM out of memory
+
+
+CDROMEJECT_SW enable(1)/disable(0) auto-ejecting
+
+ usage:
+
+ int val;
+ ioctl(fd, CDROMEJECT_SW, val);
+
+ inputs:
+ Flag specifying auto-eject flag.
+
+ outputs: none
+
+ error return:
+ ENOSYS Drive is not capable of ejecting.
+ EBUSY Door is locked
+
+
+
+
+CDROMMULTISESSION Obtain the start-of-last-session
+ address of multi session disks
+ (struct cdrom_multisession)
+ usage:
+
+ struct cdrom_multisession ms_info;
+ ioctl(fd, CDROMMULTISESSION, &ms_info);
+
+ inputs:
+ cdrom_multisession structure containing desired
+ format.
+
+ outputs:
+ cdrom_multisession structure is filled with last_session
+ information.
+
+ error return:
+ EINVAL format not CDROM_MSF or CDROM_LBA
+
+
+CDROM_GET_MCN Obtain the "Universal Product Code"
+ if available (struct cdrom_mcn)
+
+ usage:
+
+ struct cdrom_mcn mcn;
+ ioctl(fd, CDROM_GET_MCN, &mcn);
+
+ inputs: none
+
+ outputs:
+ Universal Product Code
+
+ error return:
+ ENOSYS Drive is not capable of reading MCN data.
+
+ notes:
+ Source code comments state:
+
+ The following function is implemented, although very few
+ audio discs give Universal Product Code information, which
+ should just be the Medium Catalog Number on the box. Note,
+ that the way the code is written on the CD is /not/ uniform
+ across all discs!
+
+
+
+
+CDROM_GET_UPC CDROM_GET_MCN (deprecated)
+
+ Not implemented, as of 2.6.8.1
+
+
+
+CDROMRESET hard-reset the drive
+
+ usage:
+
+ ioctl(fd, CDROMRESET, 0);
+
+ inputs: none
+
+ outputs: none
+
+ error return:
+ EACCES Access denied: requires CAP_SYS_ADMIN
+ ENOSYS Drive is not capable of resetting.
+
+
+
+
+CDROMREADCOOKED read data in cooked mode
+
+ usage:
+
+ u8 buffer[CD_FRAMESIZE]
+ ioctl(fd, CDROMREADCOOKED, buffer);
+
+ inputs: none
+
+ outputs:
+ 2048 bytes of data, "cooked" mode.
+
+ notes:
+ Not implemented on all drives.
+
+
+
+
+CDROMREADALL read all 2646 bytes
+
+ Same as CDROMREADCOOKED, but reads 2646 bytes.
+
+
+
+CDROMSEEK seek msf address
+
+ usage:
+
+ struct cdrom_msf msf;
+ ioctl(fd, CDROMSEEK, &msf);
+
+ inputs:
+ MSF address to seek to.
+
+ outputs: none
+
+
+
+CDROMPLAYBLK scsi-cd only, (struct cdrom_blk)
+
+ usage:
+
+ struct cdrom_blk blk;
+ ioctl(fd, CDROMPLAYBLK, &blk);
+
+ inputs:
+ Region to play
+
+ outputs: none
+
+
+
+CDROMGETSPINDOWN
+
+ usage:
+
+ char spindown;
+ ioctl(fd, CDROMGETSPINDOWN, &spindown);
+
+ inputs: none
+
+ outputs:
+ The value of the current 4-bit spindown value.
+
+
+
+
+CDROMSETSPINDOWN
+
+ usage:
+
+ char spindown
+ ioctl(fd, CDROMSETSPINDOWN, &spindown);
+
+ inputs:
+ 4-bit value used to control spindown (TODO: more detail here)
+
+ outputs: none
+
+
+
+
+
+CDROM_SET_OPTIONS Set behavior options
+
+ usage:
+
+ int options;
+ ioctl(fd, CDROM_SET_OPTIONS, options);
+
+ inputs:
+ New values for drive options. The logical 'or' of:
+ CDO_AUTO_CLOSE close tray on first open(2)
+ CDO_AUTO_EJECT open tray on last release
+ CDO_USE_FFLAGS use O_NONBLOCK information on open
+ CDO_LOCK lock tray on open files
+ CDO_CHECK_TYPE check type on open for data
+
+ outputs:
+ Returns the resulting options settings in the
+ ioctl return value. Returns -1 on error.
+
+ error return:
+ ENOSYS selected option(s) not supported by drive.
+
+
+
+
+CDROM_CLEAR_OPTIONS Clear behavior options
+
+ Same as CDROM_SET_OPTIONS, except that selected options are
+ turned off.
+
+
+
+CDROM_SELECT_SPEED Set the CD-ROM speed
+
+ usage:
+
+ int speed;
+ ioctl(fd, CDROM_SELECT_SPEED, speed);
+
+ inputs:
+ New drive speed.
+
+ outputs: none
+
+ error return:
+ ENOSYS speed selection not supported by drive.
+
+
+
+CDROM_SELECT_DISC Select disc (for juke-boxes)
+
+ usage:
+
+ int disk;
+ ioctl(fd, CDROM_SELECT_DISC, disk);
+
+ inputs:
+ Disk to load into drive.
+
+ outputs: none
+
+ error return:
+ EINVAL Disk number beyond capacity of drive
+
+
+
+CDROM_MEDIA_CHANGED Check is media changed
+
+ usage:
+
+ int slot;
+ ioctl(fd, CDROM_MEDIA_CHANGED, slot);
+
+ inputs:
+ Slot number to be tested, always zero except for jukeboxes.
+ May also be special values CDSL_NONE or CDSL_CURRENT
+
+ outputs:
+ Ioctl return value is 0 or 1 depending on whether the media
+ has been changed, or -1 on error.
+
+ error returns:
+ ENOSYS Drive can't detect media change
+ EINVAL Slot number beyond capacity of drive
+ ENOMEM Out of memory
+
+
+
+CDROM_DRIVE_STATUS Get tray position, etc.
+
+ usage:
+
+ int slot;
+ ioctl(fd, CDROM_DRIVE_STATUS, slot);
+
+ inputs:
+ Slot number to be tested, always zero except for jukeboxes.
+ May also be special values CDSL_NONE or CDSL_CURRENT
+
+ outputs:
+ Ioctl return value will be one of the following values
+ from <linux/cdrom.h>:
+
+ CDS_NO_INFO Information not available.
+ CDS_NO_DISC
+ CDS_TRAY_OPEN
+ CDS_DRIVE_NOT_READY
+ CDS_DISC_OK
+ -1 error
+
+ error returns:
+ ENOSYS Drive can't detect drive status
+ EINVAL Slot number beyond capacity of drive
+ ENOMEM Out of memory
+
+
+
+
+CDROM_DISC_STATUS Get disc type, etc.
+
+ usage:
+
+ ioctl(fd, CDROM_DISC_STATUS, 0);
+
+ inputs: none
+
+ outputs:
+ Ioctl return value will be one of the following values
+ from <linux/cdrom.h>:
+ CDS_NO_INFO
+ CDS_AUDIO
+ CDS_MIXED
+ CDS_XA_2_2
+ CDS_XA_2_1
+ CDS_DATA_1
+
+ error returns: none at present
+
+ notes:
+ Source code comments state:
+
+ Ok, this is where problems start. The current interface for
+ the CDROM_DISC_STATUS ioctl is flawed. It makes the false
+ assumption that CDs are all CDS_DATA_1 or all CDS_AUDIO, etc.
+ Unfortunately, while this is often the case, it is also
+ very common for CDs to have some tracks with data, and some
+ tracks with audio. Just because I feel like it, I declare
+ the following to be the best way to cope. If the CD has
+ ANY data tracks on it, it will be returned as a data CD.
+ If it has any XA tracks, I will return it as that. Now I
+ could simplify this interface by combining these returns with
+ the above, but this more clearly demonstrates the problem
+ with the current interface. Too bad this wasn't designed
+ to use bitmasks... -Erik
+
+ Well, now we have the option CDS_MIXED: a mixed-type CD.
+ User level programmers might feel the ioctl is not very
+ useful.
+ ---david
+
+
+
+
+CDROM_CHANGER_NSLOTS Get number of slots
+
+ usage:
+
+ ioctl(fd, CDROM_CHANGER_NSLOTS, 0);
+
+ inputs: none
+
+ outputs:
+ The ioctl return value will be the number of slots in a
+ CD changer. Typically 1 for non-multi-disk devices.
+
+ error returns: none
+
+
+
+CDROM_LOCKDOOR lock or unlock door
+
+ usage:
+
+ int lock;
+ ioctl(fd, CDROM_LOCKDOOR, lock);
+
+ inputs:
+ Door lock flag, 1=lock, 0=unlock
+
+ outputs: none
+
+ error returns:
+ EDRIVE_CANT_DO_THIS Door lock function not supported.
+ EBUSY Attempt to unlock when multiple users
+ have the drive open and not CAP_SYS_ADMIN
+
+ notes:
+ As of 2.6.8.1, the lock flag is a global lock, meaning that
+ all CD drives will be locked or unlocked together. This is
+ probably a bug.
+
+ The EDRIVE_CANT_DO_THIS value is defined in <linux/cdrom.h>
+ and is currently (2.6.8.1) the same as EOPNOTSUPP
+
+
+
+CDROM_DEBUG Turn debug messages on/off
+
+ usage:
+
+ int debug;
+ ioctl(fd, CDROM_DEBUG, debug);
+
+ inputs:
+ Cdrom debug flag, 0=disable, 1=enable
+
+ outputs:
+ The ioctl return value will be the new debug flag.
+
+ error return:
+ EACCES Access denied: requires CAP_SYS_ADMIN
+
+
+
+CDROM_GET_CAPABILITY get capabilities
+
+ usage:
+
+ ioctl(fd, CDROM_GET_CAPABILITY, 0);
+
+ inputs: none
+
+ outputs:
+ The ioctl return value is the current device capability
+ flags. See CDC_CLOSE_TRAY, CDC_OPEN_TRAY, etc.
+
+
+
+CDROMAUDIOBUFSIZ set the audio buffer size
+
+ usage:
+
+ int arg;
+ ioctl(fd, CDROMAUDIOBUFSIZ, val);
+
+ inputs:
+ New audio buffer size
+
+ outputs:
+ The ioctl return value is the new audio buffer size, or -1
+ on error.
+
+ error return:
+ ENOSYS Not supported by this driver.
+
+ notes:
+ Not supported by all drivers.
+
+
+
+DVD_READ_STRUCT Read structure
+
+ usage:
+
+ dvd_struct s;
+ ioctl(fd, DVD_READ_STRUCT, &s);
+
+ inputs:
+ dvd_struct structure, containing:
+ type specifies the information desired, one of
+ DVD_STRUCT_PHYSICAL, DVD_STRUCT_COPYRIGHT,
+ DVD_STRUCT_DISCKEY, DVD_STRUCT_BCA,
+ DVD_STRUCT_MANUFACT
+ physical.layer_num desired layer, indexed from 0
+ copyright.layer_num desired layer, indexed from 0
+ disckey.agid
+
+ outputs:
+ dvd_struct structure, containing:
+ physical for type == DVD_STRUCT_PHYSICAL
+ copyright for type == DVD_STRUCT_COPYRIGHT
+ disckey.value for type == DVD_STRUCT_DISCKEY
+ bca.{len,value} for type == DVD_STRUCT_BCA
+ manufact.{len,valu} for type == DVD_STRUCT_MANUFACT
+
+ error returns:
+ EINVAL physical.layer_num exceeds number of layers
+ EIO Received invalid response from drive
+
+
+
+DVD_WRITE_STRUCT Write structure
+
+ Not implemented, as of 2.6.8.1
+
+
+
+DVD_AUTH Authentication
+
+ usage:
+
+ dvd_authinfo ai;
+ ioctl(fd, DVD_AUTH, &ai);
+
+ inputs:
+ dvd_authinfo structure. See <linux/cdrom.h>
+
+ outputs:
+ dvd_authinfo structure.
+
+ error return:
+ ENOTTY ai.type not recognized.
+
+
+
+CDROM_SEND_PACKET send a packet to the drive
+
+ usage:
+
+ struct cdrom_generic_command cgc;
+ ioctl(fd, CDROM_SEND_PACKET, &cgc);
+
+ inputs:
+ cdrom_generic_command structure containing the packet to send.
+
+ outputs: none
+ cdrom_generic_command structure containing results.
+
+ error return:
+ EIO command failed.
+ EPERM Operation not permitted, either because a
+ write command was attempted on a drive which
+ is opened read-only, or because the command
+ requires CAP_SYS_RAWIO
+ EINVAL cgc.data_direction not set
+
+
+
+CDROM_NEXT_WRITABLE get next writable block
+
+ usage:
+
+ long next;
+ ioctl(fd, CDROM_NEXT_WRITABLE, &next);
+
+ inputs: none
+
+ outputs:
+ The next writable block.
+
+ notes:
+ If the device does not support this ioctl directly, the
+ ioctl will return CDROM_LAST_WRITTEN + 7.
+
+
+
+CDROM_LAST_WRITTEN get last block written on disc
+
+ usage:
+
+ long last;
+ ioctl(fd, CDROM_LAST_WRITTEN, &last);
+
+ inputs: none
+
+ outputs:
+ The last block written on disc
+
+ notes:
+ If the device does not support this ioctl directly, the
+ result is derived from the disc's table of contents. If the
+ table of contents can't be read, this ioctl returns an
+ error.
Code Review / kvmfornfv.git / blobdiff