Re: svn commit: r325320 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs [breaks lld on zfs: lld uses fallocate]

From: Mark Millard <markmi_at_dsl-only.net>
Date: Sat, 4 Nov 2017 13:13:01 -0700
On 2017-Nov-4, at 4:58 AM, Ed Maste <emaste at freebsd.org> wrote:

> On 4 November 2017 at 07:41, Andriy Gapon <avg at freebsd.org> wrote:
>> On 04/11/2017 12:32, Mark Millard wrote:
>>>  if (int Err = ::posix_fallocate(FD, 0, Size)) {
>>>    if (Err != EOPNOTSUPP)
>>>      return std::error_code(Err, std::generic_category());
>>>  }
>> 
>> The commit message that you didn't include into your reply contains some useful
>> information that authors / maintainers of this code should probably take into
>> account:
>> 
>>>  Please note that EINVAL is used to report that the underlying file system
>>>  does not support the operation (POSIX.1-2008).
>> 
>> Here is a link for that:
>> http://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fallocate.html
> 
> I have no idea how they decided EINVAL was a reasonable errno for this case.

I think they viewed it as a bad fd argument: a reference
into a wrong file system, much like a wrong len (<0) or
offset (<0).

That there is no other means of run-time classifying the
file system(s)(?) was not viewed as sufficient reason
to give it a different classification.

But it is just a guess.

===
Mark Millard
markmi at dsl-only.net
Received on Sat Nov 04 2017 - 19:13:10 UTC

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