Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of z/VM.

QDISK

Prolog  

Control Block Contents  
   QDISK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


QDISK Prolog

 Name       : QDISK control block for Virtual Disk in Storage
 Description: Q-Disk Control Block
 DSECT      : QDISK
 Function   : This control block maps the Qdisk block used
              to define and manage a virtual disk in storage.
 Located by : MDIQDISK field of MDISK block for Vdisk
 Created by : HCPQDKCR
 Deleted by : HCPQDKDS

 

QDISK Control Block Content


QDISK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      QDISK          Q-Disk Control Block
     Vdisk definition fields
0000    0 Dbl-Word     8 QDILOCK (3)    Vdisk I/O lock for this Vdisk
0018   24 Dbl-Word     8 QDIIASIT       I-ASIT for this Vdisk
0020   32 Character   24 QDISNAME       Address Space Name for this Vdisk
0038   56 Signed       4 QDIIOCNT       Count of virtual I/Os to Vdisk
003C   60 Bitstring    6 QDITOD         TOD value (used as Qdisk
                                        identifier)
0042   66 Bitstring    1 QDIDFLGS       Vdisk Definition Flags
          1... ....      QDIFWRIT       X'80' First write to Vdisk has
                                        occurred
0043   67 Bitstring    1 *              Reserved
     Data specific to a channel program
0044   68 Signed       4 QDIDATA (0)
     CCW information
0044   68 Bitstring   16 QDIDEFXT       Define Extent data (mapped by
                                        DEFXTNT DSECT in HCPQDL)
0054   84 Bitstring    8 QDILOCAT       Locate data (mapped by LOCDATA
                                        DSECT in HCPQDL)
005C   92 Bitstring    1 QDILAST        Last CCW opcode
     Flags
005D   93 Bitstring    1 QDIFLAGA       QDISK I/O Flags A
          1... ....      QDIFIRST       X'80' First CCW processing
                                        complete
          .1.. ....      QDIDFXTU       X'40' Define Extent used
          ..1. ....      QDIRIPLU       X'20' Read IPL used
          ...1 ....      QDILOCU        X'10' Locate used
          .... .1..      QDIWRITE       X'04' Writes allowed
          .... ..1.      QDIFRMAT       X'02' Formatting writes allowed
          .... ...1      QDIDIAG        X'01' Diagnostics allowed
005E   94 Bitstring    1 QDIFLAGB       QDISK I/O Flags B
          1... ....      QDIRD          X'80' Read State established
          .1.. ....      QDIRDRP        X'40' Read Replicated established
          ..1. ....      QDIWT          X'20' Write state established
          ...1 ....      QDIDRDV        X'10' Read Verify in effect
          .... 1...      QDIMEA         X'08' Microcode Erase Alert
                                        requested
          .... .1..      QDISBA         X'04' Send Block Address
                                        requested
          .... ..1.      QDIUCP         X'02' Present unit check on
                                        paging error
005F   95 Bitstring    1 QDIFLAGC       Reserved
0060   96 Bitstring    4 QDIDGDAT       Diagnostic Control data
0064  100 Signed       4 *              Reserved for future use
          00000024       QDIDATSZ       *-QDIDATA Data area size
     Sense Information
0068  104 Bitstring   32 QDISENSE       Sense data area
          00000020       QDISNSIZ       *-QDISENSE Sense data size
     Snap Data Parameter List for HCPSAC related soft abends
0088  136 Dbl-Word     8 * (0)
0088  136 Bitstring   16 QDISDPL        Snap data list
          00000010       QDISLSIZ       *-QDISDPL Snap list size
     Accounting information
0098  152 Signed       4 QDIATIM        Time of creation or last ACNT
009C  156 Character    8 QDIACTNM       Account number of owner
          00000015       QDISIZE        ((*-QDISK+7)/8) SIZE IN DWS FOR
                                        FREE/FRET

 

QDISK Storage Layout

          
*** QDISK - Q-Disk Control Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       QDILOCK                         =
*     |                                                       |
*     +-------------------------------------------------------+
*  18 |                       QDIIASIT                        |
*     +-------------------------------------------------------+
*  20 |                                                       |
*     =                       QDISNAME                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  38 |         QDIIOCNT          |         QDITOD-           |
*     +-------------+------+------+---------------------------+
*  40 |   -(03C)    |:DFLGS|//////|                           |
*     +-------------+------+------+                           |
*     |                       QDIDEFXT                        |
*     |                           +---------------------------+
*     |                           |        QDILOCAT-          |
*     +---------------------------+------+------+------+------+
*  58 |          -(054)           |:LAST |:FLAGA|:FLAGB|:FLAGC|
*     +---------------------------+------+------+------+------+
*  60 |         QDIDGDAT          |///////////////////////////|
*     +---------------------------+---------------------------+
*  68 |                                                       |
*     =                       QDISENSE                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  88 |                       QDISDPL                         |
*     |                                                       |
*     +---------------------------+---------------------------+
*  98 |         QDIATIM           |        QDIACTNM-          |
*     +---------------------------+---------------------------+
*  A0 |          -(09C)           | A4
*     +---------------------------+
*
*** QDISK - Q-Disk Control Block

 

QDISK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
QDIACTNM       009C
QDIATIM        0098
QDIDATA        0044
QDIDATSZ       0064 00000024
QDIDEFXT       0044
QDIDFLGS       0042
QDIDFXTU       005D 40
QDIDGDAT       0060
QDIDIAG        005D 01
QDIDRDV        005E 10
QDIFIRST       005D 80
QDIFLAGA       005D
QDIFLAGB       005E
QDIFLAGC       005F
QDIFRMAT       005D 02
QDIFWRIT       0042 80
QDIIASIT       0018
QDIIOCNT       0038
QDILAST        005C
QDILOCAT       0054
QDILOCK        0000
QDILOCU        005D 10
QDIMEA         005E 08
QDIRD          005E 80
QDIRDRP        005E 40
QDIRIPLU       005D 20
QDISBA         005E 04
QDISDPL        0088
QDISENSE       0068
QDISIZE        009C 00000015
QDISLSIZ       0088 00000010
QDISNAME       0020
QDISNSIZ       0068 00000020
QDITOD         003C
QDIUCP         005E 02
QDIWRITE       005D 04
QDIWT          005E 20

This information is based on z/VM V4R1.0.
Last updated on 5 Jun 2001 at 16:18:51 EDT.
Copyright IBM Corporation, 1990, 2001