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

[Mark Millard]

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.
> 
> Mark, can you give this patch a try:
> 
> diff --git a/contrib/llvm/lib/Support/Unix/Path.inc
> b/contrib/llvm/lib/Support/Unix/Path.inc
> index 45097eb918b7..67edb46f0025 100644
> --- a/contrib/llvm/lib/Support/Unix/Path.inc
> +++ b/contrib/llvm/lib/Support/Unix/Path.inc
> @@ -427,7 +427,7 @@ std::error_code resize_file(int FD, uint64_t Size) {
>   // If we have posix_fallocate use it. Unlike ftruncate it always allocates
>   // space, so we get an error if the disk is full.
>   if (int Err = ::posix_fallocate(FD, 0, Size)) {
> -    if (Err != EOPNOTSUPP)
> +    if (Err != EINVAL && Err != EOPNOTSUPP)
>       return std::error_code(Err, std::generic_category());

I've got a simple buildworld going but I expect that
it will end up using lld in a form that runs into
the problem. But I may luck out since I can link a
trivial main to produce an a.out for amd64.

It may be appropriate to have notes somewhere about
what to do for folks that land in the range -r325320
to whatever revision the updated
contrib/llvm/lib/Support/Unix/Path.inc ends up at
and that also have a zfs filesystem context involved.

I'll let you know if the build completes vs. not. It
takes a while since llvm materials are rebuilding.

===
Mark Millard
markmi at dsl-only.net