Previous topic |
Next topic |
Contents |
Contact z/OS |
Library |
PDF
System Control Blocks Used by IGGPRE00_EXIT and IGGPOST0_EXIT dynamic exits, exit routines z/OS DFSMS Installation Exits SC23-6850-01 |
|||||||||||||||||||||||||
The common IGGPRE00 and IGGPOST0 parameter list contains the addresses
of system control blocks. The following table shows the mapping macros:
For create, extend, and partial release, the address of the JFCB passed to the user exit points to a copy of the real JFCB. Updating the JFCB copy does not cause a corresponding change to the real JFCB. During catalog processing, a dummy JFCB is built with minimal information and passed to DADSM for space allocation. Certain bits that are turned on in the real JFCB might not be turned on in this dummy JFCB. For a create request on an SMS-managed volume, if the pre-processing exit changes any space amount, it will have no effect. For partial release, the DCB and DEB whose addresses appear in the parameter list are created for internal DADSM processing only. During extend processing for a VSAM data set, the exit is provided with the address of a dummy DEB. This DEB does not contain any extent information. DEBs for PDSEs and for sequential extended-format data sets contain incomplete extent information. |
Copyright IBM Corporation 1990, 2014
|