0175

Explanation

Unrecoverable errors have been encountered while processing the input log during restart. Refer to messages DFS0739A and DFS0739X, which you might receive before this abend.

This abend is related to abend 0176.

Analysis

For DFSFDLY0:

This abend is issued in module DFSFDLY0 in response to errors detected by the following modules:

DFSFDLN0

Allocate an OLDS or SLDS

DFSFDLO0

Subroutines used by DFSFDLQ0

DFSFDLP0

SLDS read

DFSFDLQ0

STATE routines used by DFSFDLX0

DFSFDLR0

Restart-read driver

DFSFDLT0

Format WADS

DFSFDLU0

Terminate OLDS from WADS

DFSFDLV0

OLDS read STATE transition table used by DFSFDLX0 contains no executable code, yet this is the heart of the OLDS read logic.

DFSFDLX0

OLDS read driver

DFSFDLY0

Subroutines used by all restart-read

DFSFDLZ0

Used in emergency restart to switch between OLDS read and SLDS read

During restart, either the input log data set encountered an unrecoverable error or log data set processing encountered a should-never-occur logic error. Message DFS0739I or DFS0739X is issued.

0175 is a standard abends that can be issued from the modules listed for this abend. The program status word (PSW) at entry-to-abend points to the instruction from which ABEND (SVC 13) is issued.

Regardless of which of the two modules actually encounters an error, all 0175 abends are accomplished by calling the common ABEND subroutine in csect DFSFDLY2 in module DFSFDLY0. Register 14 contains the return address of the caller, which should be very close to the actual point of failure. The low halfword of register 15 contains a return code that identifies the reason for the abend.

If a DBRC error is involved, the high halfword of register 15 contains the DBRC return code.

If a DFSMDA error is involved, the high halfword of register 15 contains the DFSMDA return code. (Equate statements defining the abend return codes can be found in macro DFSFRLWA.) The remaining abend registers have been saved at RLWAREGS in the restart-read work area, RLWWORK. RLWWORK is located using register 9 (or using LRESTWK in the LCD) and is mapped by macro DFSFRLWA.

If working from a formatted dump, the registers at entry to DFSFDLY2 will be close, but not necessarily identical, to the registers stored at RLWAREGS.

The following abend registers have the same meanings for all occurrences of 0175:

Reg8

Second base register for module (if needed)

Reg9

RLWWORK - restart-read work area

Reg10

LCD

Reg11

SCD

Reg12

First base register for module

Reg13

IMS pre-chained save area

Reg14

BALR return address - where the error actually occurred

Reg15

Return codes

RLWWORK is the key data area for all the logger restart-read modules and is mapped by DSECT macro DFSFRLWA. The following fields within RLWWORK are especially useful:

RLWQDECB

A copy of the parameter list passed to restart-read

RLWOLTFE

Pointer to the first entry in a table of OLDS DECB and buffer addresses. These entries are mapped by DSECT OLAT within DFSFRLWA.

RLWGLOBL

Restart-read global status flags

RLWAREQ

Last log allocation request (type) passed to DBRC

RLWALLOC

Type of log allocated

RLWDBRET

DBRC work area address

RLWDSETE

DSET entry for OLDS currently being read

RLWEN

Allocation information for log currently being read

RLWESTAT

Log status flags

RLWEEXCP

Log exception flags

RLWEAVL

Log availability flags

RLWEOPN

Log open flags

RLWEMODE

Log mode flags

RLWEOFOK

Log end-of-file (EOF) written flags

RLWECNT

Number of good blocks read on current log

RLWOSUFF

OLDS block suffix for last good block read. The OLDS suffix is mapped by DSECT SUFFIX within DFSFRLWA.

RLWPCNT

Relative block count for POINT

RLWOPDCB

OLDS primary DCB

RLWOSDCB

OLDS secondary DCB

RLWSDCB

SLDS DCB

RLWWDCB

WADS DCB

RLWAREGS

Copy of caller's registers at abend

RLWTSUFF

OLDS block suffix for first block on current OLDS. The OLDS suffix is mapped by DSECT SUFFIX within DFSFRLWA.

RLWDSUFF

OLDS block suffix for last duplicate block read. The OLDS suffix is mapped by DSECT SUFFIX within DFSFRLWA.

RLWTFLG1

OLDS error toleration flags

RLWXSTAT

OLDS XRF status flags

RLWXSTT2

OLDS XRF status flags (byte 2)

RLWHSRRT

OLDS restart-read transition table address. For more information about the OLDS restart-read transition table, please refer to the prolog for module DFSFDLV0. The OLDS restart-read transition table is mapped by DSECTs HSRRTT, XSTATBL, and XSTATENT within DFSFRLWA.

RLWXDOMA

OLDS domain mapping (prior state/event and current state/event)

RLWPPART

OLDS prior domain partition (within DFSFDLV0)

RLWCPART

OLDS current domain partition (within DFSFDLV0)

RLWNPART

OLDS next domain partition (within DFSFDLV0)

RLWXTRCN

OLDS next transition trace entry address

RLWXTRCE

OLDS end of transition trace table address

RLWXTRC

OLDS transition trace table (25 entries - 5 words each). The trace table entries are mapped by DSECT XTRCENT within DFSFRLWA. (If it becomes necessary to analyze the entries in this trace table, please contact the IBM® Support Center for assistance.)

XSXX

OLDS transition STATE equate statements

XEXX

OLDS transition EVENT equate statements

XPTINIT

OLDS transition PARTITION equate statements

RLWWPARM

WADS read parameter list passed to module DFSFDLW0

RLWABC

ABEND code save area. Equate statements for various restart-read abend codes and return codes follow RLWABC.

For DFSFDLN0:

Module DFSFDLN0 allocates the log data sets required by the restart-read process. A request is made to DBRC to locate a particular type of log data set. If the data set is located successfully, it is allocated. The following table shows the codes and an explanation for the registers:

For DFSFDLO0:

For DFSFDLP0:

Module DFSFDLP0 reads system log data sets (SLDS) during warm start or emergency restart. The following table shows the codes and an explanation for the registers:

For DFSFDLQ0:

Module DFSFDLQ0 contains all the STATE routines used to read an OLDS. There is an 8-byte eye catcher at the beginning of each STATE routine.

Module DFSFDLX0 reads the STATE table, DFSFDLV0, to determine which STATE to execute next. DFSFDLX0 calls DFSFDLQ0 with the address of the STATE routine in register 0. The STATE routine is executed and control is returned to DFSFDLX0, along with a return code. The following table shows the codes and an explanation for the registers:

For DFSFDLR0:

Module DFSFDLR0 is the driver module for the log restart-read function. DFSFLLG0 branches to DFSFDLR0 under the restart TCB to perform one of the following functions:

FIND

Locate the most current type X'42' log record (checkpoint ID table) and pass it back to restart.

The OLDS might not be terminated from the WADS during this request.

OPEN

OPEN the log containing the restart checkpoint and locate the start of the checkpoint.

READ

READ the log forward, beginning with the restart checkpoint. Pass one block of data at a time back to restart. If necessary, terminate the OLDS from the WADS.

CLOSE

After EOF on the last log, merge the data set entry tables, DSETs, (initial DSET from log initialization, DSET from the latest X'4301' log record, DSET built during forward log read) and allocate all OLDS.

FORMAT

Format the WADS as requested by the /STA WADS, /NRE, or /ERE commands.

The following table shows the codes and an explanation for the registers:

For DFSFDLR0:

Module DFSFDLU0 terminates the latest OLDS from the WADS. The following table shows the codes and an explanation for the registers:

For DFSFDLX0:

Module DFSFDLX0 is the driver for the OLDS read process. The following table shows the codes and an explanation for the registers:

For DFSFDLY0:

Module DFSFDLY0 contains all the subroutines commonly used by the restart-read modules. The following table shows the codes and an explanation for the registers:

For DFSFDLZ0:

Module DFSFDLZ0, during warm start or emergency restart, performs either OLDS read or SLDS read. The following table shows the codes and an explanation for the registers: