On 22/09/2023 23:52, Jeff Davis wrote:
src/backend/transam/README says:
...
4. Mark the shared buffer(s) as dirty with MarkBufferDirty(). (This
must happen before the WAL record is inserted; see notes in
SyncOneBuffer().)
...
But GenericXLogFinish() does this:
...
/* Insert xlog record */
lsn = XLogInsert(RM_GENERIC_ID, 0);
/* Set LSN and mark buffers dirty */
for (i = 0; i < MAX_GENERIC_XLOG_PAGES; i++)
{
PageData *pageData = &state->pages[i];
if (BufferIsInvalid(pageData->buffer))
continue;
PageSetLSN(BufferGetPage(pageData->buffer), lsn);
MarkBufferDirty(pageData->buffer);
}
END_CRIT_SECTION();
Am I missing something or is that a problem?
Yes, that's a problem.
I wish we had an assertion for that. XLogInsert() could assert that the
page is already marked dirty, for example.
--
Heikki Linnakangas
Neon (https://neon.tech)
