On Thu, Sep 29, 2022 at 7:43 PM Bharath Rupireddy
<bharath.rupireddyforpostg...@gmail.com> wrote:
>
> Please see the attached v1 patch.
FWIW, I'm attaching Nathan's patch that introduced the new function
pg_walfile_offset_lsn as 0002 in the v1 patch set. Here's the CF entry
- https://commitfest.postgresql.org/40/3909/.
Please consider this for further review.
--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
From b19aa25a0d1f2ce85abe0c2081c0e7ede256e329 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Thu, 29 Sep 2022 13:29:44 +0000
Subject: [PATCH v1] Add LSN along with offset to error messages reported for
WAL file read/write/validate header failures
---
src/backend/access/transam/xlog.c | 8 ++++++--
src/backend/access/transam/xlogreader.c | 16 +++++++++++-----
src/backend/access/transam/xlogrecovery.c | 13 ++++++++-----
src/backend/access/transam/xlogutils.c | 10 ++++++----
src/include/access/xlogreader.h | 1 +
5 files changed, 32 insertions(+), 16 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 8e15256db8..a495bbac85 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2218,6 +2218,7 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
{
char xlogfname[MAXFNAMELEN];
int save_errno;
+ XLogRecPtr lsn;
if (errno == EINTR)
continue;
@@ -2226,11 +2227,14 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
XLogFileName(xlogfname, tli, openLogSegNo,
wal_segment_size);
errno = save_errno;
+ XLogSegNoOffsetToRecPtr(openLogSegNo, startoffset,
+ wal_segment_size, lsn);
ereport(PANIC,
(errcode_for_file_access(),
errmsg("could not write to log file %s "
- "at offset %u, length %zu: %m",
- xlogfname, startoffset, nleft)));
+ "at offset %u, LSN %X/%X, length %zu: %m",
+ xlogfname, startoffset,
+ LSN_FORMAT_ARGS(lsn), nleft)));
}
nleft -= written;
from += written;
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 5a8fe81f82..c3befc44ba 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1229,9 +1229,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "invalid magic number %04X in WAL segment %s, offset %u",
+ "invalid magic number %04X in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_magic,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1243,9 +1244,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "invalid info bits %04X in WAL segment %s, offset %u",
+ "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_info,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1284,9 +1286,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
/* hmm, first page of file doesn't have a long header? */
report_invalid_record(state,
- "invalid info bits %04X in WAL segment %s, offset %u",
+ "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_info,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1303,9 +1306,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "unexpected pageaddr %X/%X in WAL segment %s, offset %u",
+ "unexpected pageaddr %X/%X in WAL segment %s, LSN %X/%X, offset %u",
LSN_FORMAT_ARGS(hdr->xlp_pageaddr),
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1328,10 +1332,11 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "out-of-sequence timeline ID %u (after %u) in WAL segment %s, offset %u",
+ "out-of-sequence timeline ID %u (after %u) in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_tli,
state->latestPageTLI,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1556,6 +1561,7 @@ WALRead(XLogReaderState *state,
errinfo->wre_req = segbytes;
errinfo->wre_read = readbytes;
errinfo->wre_off = startoff;
+ errinfo->wre_lsn = recptr;
errinfo->wre_seg = state->seg;
return false;
}
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index cb07694aea..c6ffb29c05 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -3079,9 +3079,10 @@ ReadRecord(XLogPrefetcher *xlogprefetcher, int emode,
XLogFileName(fname, xlogreader->seg.ws_tli, segno,
wal_segment_size);
ereport(emode_for_corrupt_record(emode, xlogreader->EndRecPtr),
- (errmsg("unexpected timeline ID %u in WAL segment %s, offset %u",
+ (errmsg("unexpected timeline ID %u in WAL segment %s, LSN %X/%X, offset %u",
xlogreader->latestPageTLI,
fname,
+ LSN_FORMAT_ARGS(xlogreader->latestPagePtr),
offset)));
record = NULL;
}
@@ -3284,14 +3285,16 @@ retry:
errno = save_errno;
ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
(errcode_for_file_access(),
- errmsg("could not read from WAL segment %s, offset %u: %m",
- fname, readOff)));
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %u: %m",
+ fname, LSN_FORMAT_ARGS(targetPagePtr),
+ readOff)));
}
else
ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
(errcode(ERRCODE_DATA_CORRUPTED),
- errmsg("could not read from WAL segment %s, offset %u: read %d of %zu",
- fname, readOff, r, (Size) XLOG_BLCKSZ)));
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %u: read %d of %zu",
+ fname, LSN_FORMAT_ARGS(targetPagePtr),
+ readOff, r, (Size) XLOG_BLCKSZ)));
goto next_record_is_invalid;
}
pgstat_report_wait_end();
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index 563cba258d..9d171f2ad9 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -1051,15 +1051,17 @@ WALReadRaiseError(WALReadError *errinfo)
errno = errinfo->wre_errno;
ereport(ERROR,
(errcode_for_file_access(),
- errmsg("could not read from WAL segment %s, offset %d: %m",
- fname, errinfo->wre_off)));
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %d: %m",
+ fname, LSN_FORMAT_ARGS(errinfo->wre_lsn),
+ errinfo->wre_off)));
}
else if (errinfo->wre_read == 0)
{
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
- errmsg("could not read from WAL segment %s, offset %d: read %d of %d",
- fname, errinfo->wre_off, errinfo->wre_read,
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %d: read %d of %d",
+ fname, LSN_FORMAT_ARGS(errinfo->wre_lsn),
+ errinfo->wre_off, errinfo->wre_read,
errinfo->wre_req)));
}
}
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e87f91316a..1e47169b5a 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -386,6 +386,7 @@ typedef struct WALReadError
int wre_off; /* Offset we tried to read from. */
int wre_req; /* Bytes requested to be read. */
int wre_read; /* Bytes read by the last read(). */
+ XLogRecPtr wre_lsn; /* WAL LSN being read. */
WALOpenSegment wre_seg; /* Segment we tried to read from. */
} WALReadError;
--
2.34.1
From f8ed45d9fa59690d8b3375d658c1baedb8510195 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathandbossart@gmail.com>
Date: Mon, 19 Sep 2022 20:24:10 -0700
Subject: [PATCH v1 1/1] introduce pg_walfile_offset_lsn()
---
doc/src/sgml/func.sgml | 14 +++++++
src/backend/access/transam/xlogfuncs.c | 39 ++++++++++++++++++++
src/include/catalog/pg_proc.dat | 5 +++
src/test/regress/expected/misc_functions.out | 19 ++++++++++
src/test/regress/sql/misc_functions.sql | 9 +++++
5 files changed, 86 insertions(+)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 67eb380632..318ac22769 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25891,6 +25891,20 @@ LOG: Grand total: 1651920 bytes in 201 blocks; 622360 free (88 chunks); 1029560
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_walfile_offset_lsn</primary>
+ </indexterm>
+ <function>pg_walfile_offset_lsn</function> ( <parameter>file_name</parameter> <type>text</type>, <parameter>file_offset</parameter> <type>integer</type> )
+ <returnvalue>pg_lsn</returnvalue>
+ </para>
+ <para>
+ Converts a WAL file name and byte offset within that file to a
+ write-ahead log location.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index 27aeb6e281..75f58cb118 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -313,6 +313,45 @@ pg_last_wal_replay_lsn(PG_FUNCTION_ARGS)
PG_RETURN_LSN(recptr);
}
+/*
+ * Compute an LSN given a WAL file name and decimal byte offset.
+ */
+Datum
+pg_walfile_offset_lsn(PG_FUNCTION_ARGS)
+{
+ char *filename = text_to_cstring(PG_GETARG_TEXT_PP(0));
+ int offset = PG_GETARG_INT32(1);
+ TimeLineID tli;
+ XLogSegNo segno;
+ XLogRecPtr result;
+ uint32 log;
+ uint32 seg;
+
+ if (!IsXLogFileName(filename))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid WAL file name \"%s\"", filename)));
+
+ sscanf(filename, "%08X%08X%08X", &tli, &log, &seg);
+ if (seg >= XLogSegmentsPerXLogId(wal_segment_size) ||
+ (log == 0 && seg == 0) ||
+ tli == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid WAL file name \"%s\"", filename)));
+
+ if (offset < 0 || offset >= wal_segment_size)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("\"offset\" must not be negative or greater than or "
+ "equal to WAL segment size")));
+
+ XLogFromFileName(filename, &tli, &segno, wal_segment_size);
+ XLogSegNoOffsetToRecPtr(segno, offset, wal_segment_size, result);
+
+ PG_RETURN_LSN(result);
+}
+
/*
* Compute an xlog file name and decimal byte offset given a WAL location,
* such as is returned by pg_backup_stop() or pg_switch_wal().
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index a07e737a33..224fe590ac 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6328,6 +6328,11 @@
proargtypes => 'pg_lsn', proallargtypes => '{pg_lsn,text,int4}',
proargmodes => '{i,o,o}', proargnames => '{lsn,file_name,file_offset}',
prosrc => 'pg_walfile_name_offset' },
+{ oid => '8205',
+ descr => 'wal location, given a wal filename and byte offset',
+ proname => 'pg_walfile_offset_lsn', prorettype => 'pg_lsn',
+ proargtypes => 'text int4', proargnames => '{file_name,file_offset}',
+ prosrc => 'pg_walfile_offset_lsn' },
{ oid => '2851', descr => 'wal filename, given a wal location',
proname => 'pg_walfile_name', prorettype => 'text', proargtypes => 'pg_lsn',
prosrc => 'pg_walfile_name' },
diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out
index 9f106c2a10..b2d6f23ac1 100644
--- a/src/test/regress/expected/misc_functions.out
+++ b/src/test/regress/expected/misc_functions.out
@@ -594,3 +594,22 @@ SELECT * FROM tenk1 a JOIN my_gen_series(1,10) g ON a.unique1 = g;
Index Cond: (unique1 = g.g)
(4 rows)
+-- pg_walfile_offset_lsn
+SELECT pg_walfile_offset_lsn('invalid', 15);
+ERROR: invalid WAL file name "invalid"
+SELECT pg_walfile_offset_lsn('0000000100000000FFFFFFFF', 15);
+ERROR: invalid WAL file name "0000000100000000FFFFFFFF"
+SELECT pg_walfile_offset_lsn('000000010000000000000000', 15);
+ERROR: invalid WAL file name "000000010000000000000000"
+SELECT pg_walfile_offset_lsn('000000000000000100000000', 15);
+ERROR: invalid WAL file name "000000000000000100000000"
+SELECT pg_walfile_offset_lsn('000000010000000100000000', -1);
+ERROR: "offset" must not be negative or greater than or equal to WAL segment size
+SELECT pg_walfile_offset_lsn('000000010000000100000000', 2000000000);
+ERROR: "offset" must not be negative or greater than or equal to WAL segment size
+SELECT pg_walfile_offset_lsn('000000010000000100000000', 15);
+ pg_walfile_offset_lsn
+-----------------------
+ 1/F
+(1 row)
+
diff --git a/src/test/regress/sql/misc_functions.sql b/src/test/regress/sql/misc_functions.sql
index 639e9b352c..cb54901029 100644
--- a/src/test/regress/sql/misc_functions.sql
+++ b/src/test/regress/sql/misc_functions.sql
@@ -223,3 +223,12 @@ SELECT * FROM tenk1 a JOIN my_gen_series(1,1000) g ON a.unique1 = g;
EXPLAIN (COSTS OFF)
SELECT * FROM tenk1 a JOIN my_gen_series(1,10) g ON a.unique1 = g;
+
+-- pg_walfile_offset_lsn
+SELECT pg_walfile_offset_lsn('invalid', 15);
+SELECT pg_walfile_offset_lsn('0000000100000000FFFFFFFF', 15);
+SELECT pg_walfile_offset_lsn('000000010000000000000000', 15);
+SELECT pg_walfile_offset_lsn('000000000000000100000000', 15);
+SELECT pg_walfile_offset_lsn('000000010000000100000000', -1);
+SELECT pg_walfile_offset_lsn('000000010000000100000000', 2000000000);
+SELECT pg_walfile_offset_lsn('000000010000000100000000', 15);
--
2.25.1
