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Add more error context to RestoreBlockImage() and consume it

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On failure in restoring a block image, no details were provided, while
it is possible to see failure with an inconsistent record state, a
failure in processing decompression or a failure in decompression
because a build does not support this option.

RestoreBlockImage() is used in two code paths in the backend code,
during recovery and when checking a page consistency after applying
masking, and both places are changed to consume the error message
produced by the internal routine when it returns a false status.  All
the error messages are reported under ERRCODE_INTERNAL_ERROR, that gets
used also when attempting to access a page compressed by a method
not supported by the build attempting the decompression.  This is
something that can happen in core when doing physical replication with
primary and standby using inconsistent build options, for example.

This routine is available since 2c03216d and it has never provided any
context about the error happening when it failed.  This change is
justified even more after 57aa5b2, that introduced compression of FPWs
in WAL.

Reported-by: Justin Prysby
Author: Michael Paquier
Discussion: https://postgr.es/m/20220905002320.GD31833@telsasoft.com
Backpatch-through: 15
This commit is contained in:
Michael Paquier 2022-09-09 10:00:40 +09:00
parent d977ffd923
commit df4a056619
3 changed files with 23 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
src/backend/access/transam/xlogreader.c
View File

@ -2036,7 +2036,8 @@ XLogRecGetBlockData(XLogReaderState *record, uint8 block_id, Size *len)
/*
* Restore a full-page image from a backup block attached to an XLOG record.
*
* Returns true if a full-page image is restored.
* Returns true if a full-page image is restored, and false on failure with
* an error to be consumed by the caller.
*/
bool
RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
@ -2047,9 +2048,20 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
if (block_id > record->record->max_block_id ||
!record->record->blocks[block_id].in_use)
{
report_invalid_record(record,
"could not restore image at %X/%X with invalid block %d specified",
LSN_FORMAT_ARGS(record->ReadRecPtr),
block_id);
return false;
}
if (!record->record->blocks[block_id].has_image)
{
report_invalid_record(record, "could not restore image at %X/%X with invalid state, block %d",
LSN_FORMAT_ARGS(record->ReadRecPtr),
block_id);
return false;
}
bkpb = &record->record->blocks[block_id];
ptr = bkpb->bkp_image;
@ -2072,7 +2084,7 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
bkpb->bimg_len, BLCKSZ - bkpb->hole_length) <= 0)
decomp_success = false;
#else
report_invalid_record(record, "image at %X/%X compressed with %s not supported by build, block %d",
report_invalid_record(record, "could not restore image at %X/%X compressed with %s not supported by build, block %d",
LSN_FORMAT_ARGS(record->ReadRecPtr),
"LZ4",
block_id);
@ -2089,7 +2101,7 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
if (ZSTD_isError(decomp_result))
decomp_success = false;
#else
report_invalid_record(record, "image at %X/%X compressed with %s not supported by build, block %d",
report_invalid_record(record, "could not restore image at %X/%X compressed with %s not supported by build, block %d",
LSN_FORMAT_ARGS(record->ReadRecPtr),
"zstd",
block_id);
@ -2098,7 +2110,7 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
}
else
{
report_invalid_record(record, "image at %X/%X compressed with unknown method, block %d",
report_invalid_record(record, "could not restore image at %X/%X compressed with unknown method, block %d",
LSN_FORMAT_ARGS(record->ReadRecPtr),
block_id);
return false;
@ -2106,7 +2118,7 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
if (!decomp_success)
{
report_invalid_record(record, "invalid compressed image at %X/%X, block %d",
report_invalid_record(record, "could not decompress image at %X/%X, block %d",
LSN_FORMAT_ARGS(record->ReadRecPtr),
block_id);
return false;

4
src/backend/access/transam/xlogrecovery.c
View File

@ -2412,7 +2412,9 @@ verifyBackupPageConsistency(XLogReaderState *record)
* can be directly applied on it.
*/
if (!RestoreBlockImage(record, block_id, primary_image_masked))
elog(ERROR, "failed to restore block image");
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg_internal("%s", record->errormsg_buf)));
/*
* If masking function is defined, mask both the primary and replay

4
src/backend/access/transam/xlogutils.c
View File

@ -393,7 +393,9 @@ XLogReadBufferForRedoExtended(XLogReaderState *record,
prefetch_buffer);
page = BufferGetPage(*buf);
if (!RestoreBlockImage(record, block_id, page))
elog(ERROR, "failed to restore block image");
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg_internal("%s", record->errormsg_buf)));
/*
* The page may be uninitialized. If so, we can't set the LSN because