On Fri, Oct 18, 2019 at 2:26 PM Thomas Munro <thomas.mu...@gmail.com> wrote: > On Fri, Oct 18, 2019 at 1:21 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Thomas Munro <thomas.mu...@gmail.com> writes: > > > On Tue, Oct 15, 2019 at 1:55 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > > >> and now prairiedog has shown it too: > > >> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=prairiedog&dt=2019-10-14%2021%3A45%3A47 > > >> which is positively fascinating, because prairiedog is running a > > >> bronze-age version of macOS that surely never heard of APFS. > > >> So this makes it look like this is a basic macOS bug that's not > > >> as filesystem-dependent as one might think. > > > > > Does https://github.com/macdice/unlinktest show the problem on that > > > system? > > > > It does, though with a very low frequency: > > > > $ ./unlinktest > > $ ./unlinktest 10000 > > read 0 bytes, unexpected > > $ ./unlinktest 10000 > > read 0 bytes, unexpected > > read 0 bytes, unexpected > > $ ./unlinktest 10000 > > $ > > > > The failure rate on my recent-vintage laptop is more like one > > failure every five loops. > > Wow. Ok, I'll add a note to the bug report to say it's reproducible > on "Darwin Kernel Version 8.11.0: Wed Oct 10 18:26:00 PDT 2007; > root:xnu-792.24.17~1/RELEASE_PPC" next time I'm near an Apple device > that will let me log into the bug thing. On the off-chance that > someone from Apple stumbles on this and is interested, the Radar > number is rdar://46318934 and the title is "unlink(2) is not atomic > (kernel/file system bug)".
My bug report got an automated-looking message telling me to retest in Big Sur beta 6 back in September, and I've just now upgraded an old x86 Mac to Big Sur 11.01 and I can no longer reproduce the problem, so it looks like it was fixed! Thanks, Apple.
