Disconnect if socket cannot be put into non-blocking mode Commit 387da18874 moved the code to put socket into non-blocking mode from socket_set_nonblocking() into the one-time initialization function, pq_init(). In socket_set_nonblocking(), there indeed was a risk of recursion on failure like the comment said, but in pq_init(), ERROR or FATAL is fine. There's even another elog(FATAL) just after this, if setting FD_CLOEXEC fails.
Note that COMMERROR merely logged the error, it did not close the connection, so if putting the socket to non-blocking mode failed we would use the connection anyway. You might not immediately notice, because most socket operations in a regular backend wait for the socket to become readable/writable anyway. But e.g. replication will be quite broken. Backpatch to all supported versions. Discussion: https://www.postgresql.org/message-id/d40a5cd0-2722-40c5-8755-12e9e811f...@iki.fi Branch ------ REL_15_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/4fce5f970d584114ba9f981b367eb7720621cc50 Modified Files -------------- src/backend/libpq/pqcomm.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)