Controlling Bypass Label Processing (BLP)

You can use Z Data Tools to control tape label processing by your users even if your system installation parameters (JES parameters) would not allow BLP.

If your installation allows BLP usage (as specified in your JES parameters), normal open processing checks if the user has access to ICHBLP. Any user with READ access or greater can use BLP. If ICHBLP is not defined to your security product, all users can use BLP.

If your installation does not allow BLP usage (as specified in your JES parameters), then if LABEL=(,BLP) is coded on the JCL control statement, BLP is converted to NL. However, Z Data Tools users can still use BLP subject to the following conditions:
  • Z Data Tools must be running APF-authorized.
  • For any function other than TLB, the user must have access to FILEM.TAPE.BLP.
  • If ICHBLP is defined to your security product, the user must have READ access or greater to it.
In this case, if either of the following is coded on the JCL control statement:
  • LABEL=(,BLP)
  • LABEL=(,NL)
the user can specify LABEL=BLP on the first Z Data Tools function that uses a tape. This means that the user wants to use bypass label processing (BLP) for the tape.
This is illustrated in BLP processing by Z Data Tools.
Figure 1. BLP processing by Z Data Tools
  ┌──────────────────────────────────────────┐
  │Installation allows BLP usage (JES parms)?│
  ├──────────────────┬───────────────────────┤
  │      Yes         │        No             │
  └──────┬───────────┴────────────┬──────────┘
         │                        ↓
         │               ┌────────────────────────────────┐
         │               │System converts BLP on JCL to NL│
         │               └────────┬───────────────────────┘
         │                        ↓
         │               ┌───────────────────────────────────┐
         │               │Z Data Tools tape function with    │
         │               │LABEL=BLP on control statement?    │
         │               ├────────────────┬──────────────────┤
         │               │      Yes       │       No         │
         │               └────────┬───────┴────────┬─────────┘
         │                        ↓                └─────────────────┐
         │               ┌─────────────────┐                         │
         │               │APF-authorized?  │                         │
         │               ├──────┬──────────┤                         │
         │               │ Yes  │   No     │                         │
         │               └──┬───┴────┬─────┘                         │
         │                  ↓        └───────────────────────┐       │
         │               ┌─────────────────┐                 │       │
         │               │Which function?  │                 │       │
         │               ├──────┬──────────┤                 │       │
         │               │  TLB │ other    │                 │       │
         │               └──┬───┴────┬─────┘                 │       │
         │            ┌─────┘        ↓                       │       │
         │            │  ┌───────────────────────────────┐   │       │
         │            │  │FACILITY(FILEM.TAPE.BLP) access│   │       │
         │            │  ├───────┬────────┬──────┬───────┤   │       │
         │            │  │ ALTER │ UPDATE │ READ │ NONE  │   │       │
         │            │  └───┬───┴────┬───┴──┬───┴───┬───┘   │       │
         │            │      └─┬──────┴──────┘       │       │       │
         │            ↓        ↓                     ↓       ↓       ↓
         │         ┌────────────────────────┐  ┌─────────────────────────────┐
         │         │Z Data Tools forces BLP │  │Z Data Tools can't force BLP │
         │         └────────────┬───────────┘  └─────────────────────────────┘
         ↓                      ↓
  ┌───────────────────────────────────────────┐
  │Open processing checks access to ICHBLP    │
  ├────────────┬───────┬────────┬──────┬──────┤
  │Not defined │ ALTER │ UPDATE │ READ │ NONE │
  └──────┬─────┴──┬────┴────┬───┴──┬───┴───┬──┘
         ├────────┴─────────┴──────┘       │
         ↓                                 ↓
 ┌────────────────────────┐  ┌───────────────────────────────────┐
 │ Z Data Tools uses BLP  │  │ Z Data Tools abends with S913-64  │
 └────────────────────────┘  └───────────────────────────────────┘