"Magnus Hagander" <mha@sollentuna.net> writes:
> Because we are talking about checking the output from _commit(), right?
> (being fsync() redefined)
The failure could be coming from that, or from a preceding open() if the
bgwriter didn't already have the file open --- basically, the message
Peter is quoting indicates a failure return from FileSync() in fd.c.
The fact that it doesn't happen for him every time is pretty good
evidence that only one of those two cases fails.
regards, tom lane