Re: BUG #15636: PostgreSQL 11.1 pg_basebackup backup to a CIFS destination throws fsync error at end of backup

On Sat, Feb 16, 2019 at 4:39 AM John Klann <jk7255(at)gmail(dot)com> wrote:
> I was able to test the patch without issue and it appears to have worked see below. Let me know if there is further testing I can do or logging you would like.

Thanks. So that leaves the question for the list: should we accept
this as a bug and consider back-patching it? Our relationship with
fsync() is ... complicated at the moment. Considering that we already
tolerated EBADF for directories on some other (forgotten?) operating
system, I think I would vote +1 for doing that ... if I didn't know
that they'd fixed this on the Linux side, and I see now that they've
back-patched that even to long term kernel 3.16:

https://cdn.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.16.60

You mentioned that you were on RHEL 7.5, which ships with a 3.10
kernel. When you eventually move to RHEL 8 (4.x) or even install an
alternative newer kernel for 7.x, the problem will hopefully go away
by itself. Considering that, the lack of other complaints, and the
availability of a workaround (--no-sync followed by "sync"), I'm not
so sure it's worth committing this.

PS I found an earlier discussion of this topic that didn't go
anywhere: https://www.postgresql.org/message-id/flat/E1RhkjA-0005bq-B6%40wrigleys.postgresql.org

--
Thomas Munro
http://www.enterprisedb.com