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

Hi,

On 2019-02-23 11:20:02 +1300, Thomas Munro wrote:
> So, for this patch tolerating EINVAL for fsync of directories (but not
> files), enabling eg pg_backbackup on CIFS on eg Linux 3.10 to work,
> tested by John, we have:
> 
> Stephen: +1
> Michael: -0.1
> Thomas: -0.1
> 
> Any other opinions?
> 
> Just in case you think it's strange that I'm voting against my own
> patch: I'd probably be for it if I hadn't discovered that they've
> fixed this in Linux 3.16 and later so that it succeeds.  It's
> apparently not in the default RHEL 6 and 7 kernels, though, and the
> latter could be around for a while.  I'm not entirely sure what amount
> of work we should be doing to tolerate problems that are fixed in a
> newer versions.  One argument is that a 3.10 user who cares about this
> should petition RH to back-port the fix into that kernel.  (The nearby
> WSL thread has some things in common but is a more clear cut case IMV
> because there is no fix available on the WSL side.)

Hm, given the fact that EINVAL doesn't appear to be triggerable by data
level issues, I don't see much reason not to allow it. I mean it's
really stupid that cifs ever returns it, but there's going to be a lot
of users running things on older kernel for the forseeable future.

Greetings,

Andres Freund