David Chinner wrote:
Let me say that I have noticed that using ALLOCSP seems to create less extents
than posix_fallocate/manual zeroing.
yeah... ISTR that the arguments are funky. I can't remember if it's a
bug or not. :) FWIW, allocsp just writes zeros to the file, so you
could do it just as well from userspace w/ no fancy ioctls... ALLOCSP
is a bit pointless if you ask me... though maybe someone knows why it's
Yes, that's likely ;)
There's work currently active to make posix_fallocate() do the same thing
as ALLOCSP (i.e. call into the filesystem and let it do smart stuff), but
that's a ways off yet...
Dave, doesn't ALLOCSP actually create actual zeroed space though?
Pretty much as posix_fallocate from userspace does today, maybe with
better allocation... And "smart stuff" would be *not* needing to write
zeros.... i.e. what RESVSP does.