mkfs: allow sizing allocation groups for concurrency

Add a -d concurrency= option to mkfs so that sysadmins can configure the
filesystem so that there are enough allocation groups that the specified
number of threads can (in theory) can find an uncontended group to
allocate space from.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
2 files changed