Prevent race condition while reading relmapper file. Contrary to the comment here, POSIX does not guarantee atomicity of a read(), if another process calls write() concurrently. Or at least Linux does not. Add locking to load_relmap_file() to avoid the race condition.
Fixes bug #17064. Thanks to Alexander Lakhin for the report and test case. Backpatch-through: 9.6, all supported versions. Discussion: https://www.postgresql.org/message-id/17064-bb0d7904ef72a...@postgresql.org Branch ------ REL_11_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/c78bb32c19fe0b69d8ce75d6304c2394c4c7cd6b Modified Files -------------- src/backend/utils/cache/relmapper.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-)
