Re: [QUESTION] zig build systems fails on XFS V4 volumes

[Donald Buczek <buczek@molgen.mpg.de>]

On 2/5/24 22:13, Dave Chinner wrote:
> On Mon, Feb 05, 2024 at 02:12:43PM +0100, Donald Buczek wrote:
>> On 2/4/24 22:56, Dave Chinner wrote:
>>> On Sat, Feb 03, 2024 at 06:50:31PM +0100, Donald Buczek wrote:
>>>> Dear Experts,
>>>>
>>>> I'm encountering consistent build failures with the Zig
>>>> language from source on certain systems, and I'm seeking
>>>> insights into the issue.
>>>>

> The reason for this difference seems obvious: there's a distinct
> lack of stat() calls in the ftype=0 (bad) case. dirent->d_type in
> this situation will be reporting DT_UNKNOWN for all entries except
> '.' and '..'. It is the application's responsibility to handle this,
> as the only way to determine if a DT_UNKNOWN entry is a directory is
> to stat() the pathname and look at the st_mode returned.

You've nailed it. [1][2]

I'll take this over to the zig community.

Thanks!

   Donald

[1]: https://github.com/ziglang/zig/blob/39ec3d311673716e145957d6d81f9d4ec7848471/lib/std/fs/Dir.zig#L372
[2]: https://github.com/ziglang/zig/blob/39ec3d311673716e145957d6d81f9d4ec7848471/lib/std/fs/Dir.zig#L669

> 
> The code is clearly not doing this, and so I'm guessing that the zig
> people have rolled their own nftw() function and didn't pay
> attention to the getdents() man page:
> 
> 	Currently,  only some filesystems (among them: Btrfs, ext2,
> 	ext3, and ext4) have full support for returning the file
> 	type in d_type.  All applications must properly handle a
> 	return of DT_UNKNOWN.
> 
> So, yeah, looks like someone didn't read the getdents man page
> completely and it's not a filesystem issue.
> 
> -Dave.

-- 
Donald Buczek
buczek@molgen.mpg.de
Tel: +49 30 8413 1433