bufmgr: Fix order of operations in UnlockBufHdrExt In c75ebc657ffc I (Andres) introduced UnlockBufHdrExt() which can set and clear bits in the buffer state using CAS. Unfortunately I added bits before subtracting them, which means that a bit that was both removed and set would remain unset. Fix the order of operations.
The only known case where that is a problem is that BM_IO_ERROR would not actually remain set. It's unfortunately not trivial to add a decent, race-free, test to verify that BM_IO_ERROR remains set. That's therefore left for the 20 cycle. Reported-by: Yura Sokolov <[email protected]> Discussion: https://postgr.es/m/[email protected] Backpatch-through: 19, where c75ebc657ffc went in Branch ------ REL_19_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/a1b74b7279c24638c44f9d3d1af2da30cfb7068d Modified Files -------------- src/include/storage/buf_internals.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
