Use GetXLogInsertEndRecPtr in gistGetFakeLSN The function used GetXLogInsertRecPtr() to generate the fake LSN. Most of the time this is the same as what XLogInsert() would return, and so it works fine with the XLogFlush() call. But if the last record ends at a page boundary, GetXLogInsertRecPtr() returns LSN pointing after the page header. In such case XLogFlush() fails with errors like this:
ERROR: xlog flush request 0/01BD2018 is not satisfied --- flushed only to 0/01BD2000 Such failures are very hard to trigger, particularly outside aggressive test scenarios. Fixed by introducing GetXLogInsertEndRecPtr(), returning the correct LSN without skipping the header. This is the same as GetXLogInsertRecPtr(), except that it calls XLogBytePosToEndRecPtr(). Initial investigation by me, root cause identified by Andres Freund. This is a long-standing bug in gistGetFakeLSN(), probably introduced by c6b92041d38 in PG13. Backpatch to all supported versions. Reported-by: Peter Geoghegan <[email protected]> Reviewed-by: Andres Freund <[email protected]> Reviewed-by: Noah Misch <[email protected]> Discussion: https://postgr.es/m/vf4hbwrotvhbgcnknrqmfbqlu75oyjkmausvy66ic7x7vuhafx@e4rvwavtjswo Backpatch-through: 14 Branch ------ REL_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/c0ffc725f8b3ae51a5755233bd84499b8221f92e Modified Files -------------- src/backend/access/gist/gistutil.c | 2 +- src/backend/access/transam/xlog.c | 16 ++++++++++++++++ src/include/access/xlog.h | 1 + 3 files changed, 18 insertions(+), 1 deletion(-)
