Hi Andreas,
Andreas Dilger <adil...@dilger.ca> writes:
> On Jan 20, 2018, at 5:06 PM, Mark H Weaver <m...@netris.org> wrote:
>> Yes, on Btrfs I reliably see (st_blocks == 0) on a recently written,
>> mostly sparse file with size > 8G, using linux-libre-4.14.14. More
>> specifically, the "storing sparse files > 8G" test in tar's test suite
>> reliably fails on my system:
>>
>> 140: storing sparse files > 8G FAILED (sparse03.at:29)
>
> I'd consider this a bug in Btrfs.
On what basis? Can you formulate a precise rule regarding 'st_blocks'
that is worth defending, that would enable this optimization, and that
Btrfs is violating here?
> As mentioned previously, we had the same problem with ext4 (twice) and
> Lustre, and in both cases fixed this by adding in the (dirty page
> cache pages/512) if the current block count is zero:
Would you like to propose a fix to the Btrfs developers?
Mark
