Bug in Samba's implementation of FSCTL_QUERY_ALLOCATED_RANGES?

[David Disseldorp]

On Wed, 28 Aug 2024 12:52:25 +0100, David Howells via samba-technical wrote:

> Okay, that fixes the problem.
> 
> For reference, the file can be prepared thusly:
> 
> 	xfs_io -c "pwrite 0 16M" -c "fpunch 0 1M" -c "fpunch 2M 1M" -c "fpunch 4M 1M" -c "fpunch 6M 1M" -c "fpunch 8M 1M" /xfstest.test/foo
> 
> and then the test run:
> 
> 	xfs_io -c "seek -h 1" /xfstest.test/foo
> 
> Something like punch-hole is needed to set the sparse flag - otherwise QAR
> isn't used by llseek().
> 
> So:
> 
> 	Tested-by: David Howells <dhowells at redhat.com>
> 
> if you need it.

I appreciate the test feedback. The change has already been committed
(with you referenced in Reported-by).

> The Fedora samba version I applied this to was:
> 
> 	samba-4.19.7-1.fc39.x86_64
> 
> though I had to drop the testing bits as they didn't build.

Yes, as mentioned, samba >= 4.20 is needed for the test's
torture_assert_size_equal() calls.

Cheers, David