Comment # 4 on bug 1089480 from Wenruo Qu

So it's not the cache pages causing the problem.

It's highly possible for the meta/data reserved space causing the problem.
Since I'm no familiar with 64K sectorsize, I can't be 100% sure.

Would you please removing all files of the testing subvolumes, and sync the fs
using 'btrfs sub sync'.
And finally try to fill the subvolume again, to see if we can still only reach
that number.

If so, we need extra info on the 64K sector size btrfs.


And if possible, is there anyway to config the kernel on ppc64 to use 4K page
size and re-test?

Thanks,
Qu