bug#20570: Test dd/sparse.sh fail with btrfs

[Pádraig Brady]

On 14/05/15 03:53, Sébastien Luttringer wrote:
> Hello,
> 
> I experience one test suite failure when I tried to rebuild the
> coreutils v8.23 package. My system is an archlinux host with a btrfs
> filesystem.
> 
> The test doesn't fail when I run it in a tmpfs. I'm pretty sure it used
> to works over btrfs in july 2014[1] when I built the previous package
> for archlinux.
> 
> The failing section is the following:
> 
>   # Ensure NUL blocks smaller than the block size are not made sparse.
>   # Here, with a 2MiB block size, dd's conv=sparse must *not*
> introduce a hole. 
>   dd if=file.in of=file.out bs=2M conv=sparse
>   test 2500 -lt $(kb_alloc file.out) || fail=1
> 
> You can see the full shell output here: http://pastebin.com/XADb1BKj
> 
> Regards,
> 
> [1] https://www.archlinux.org/packages/core/x86_64/coreutils/

It seems the allocation is async.
I also see this intermittently with BTRFS on 4.0.0-0.rc5.git4.1.fc22.x86_64
I've been unable to reproduce with the attached
which syncs the file before checking the allocation.

thanks!
Pádraig.

dd-sparse-btrfs.patch
Description: Text Data