Re: Postgres, fsync, and OSs (specifically linux)

On 21 May 2018 at 12:57, Craig Ringer <craig(at)2ndquadrant(dot)com> wrote:

> On 18 May 2018 at 00:44, Andres Freund <andres(at)anarazel(dot)de> wrote:
>
>> Hi,
>>
>> On 2018-05-10 09:50:03 +0800, Craig Ringer wrote:
>> > while ((src = (RewriteMappingFile *)
>> hash_seq_search(&seq_status)) != NULL)
>> > {
>> > if (FileSync(src->vfd, WAIT_EVENT_LOGICAL_REWRITE_SYNC)
>> != 0)
>> > - ereport(ERROR,
>> > + ereport(PANIC,
>> > (errcode_for_file_access(),
>> > errmsg("could not fsync file
>> \"%s\": %m", src->path)));
>>
>> To me this (and the other callers) doesn't quite look right. First, I
>> think we should probably be a bit more restrictive about when PANIC
>> out. It seems like we should PANIC on ENOSPC and EIO, but possibly not
>> others. Secondly, I think we should centralize the error handling. It
>> seems likely that we'll acrue some platform specific workarounds, and I
>> don't want to copy that knowledge everywhere.
>>
>> Also, don't we need the same on close()?
>>
>>
> Yes, we do, and that expands the scope a bit.
>
> I agree with Robert that some sort of filter/macro is wise, though naming
> it clearly will be tricky.
>
> I'll have a look.
>
>
On the queue for tomorrow.

--
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services