[PATCH 04/16] xfs: dynamic speculative EOF preallocation

[Christoph Hellwig]

> For default settings, ???e size and the initial extents is determined

weird character.

> The allocsize mount option still controls the minimum preallocation size, so
> the smallest extent size can stil be bound in situations where this behaviour
> is not sufficient.

Do we also need a way to keep an upper boundary?  Think lots of slowly
growing log files on a filesystem not having tons of free space.