Add support for runtime log compression

If log_compression=64M is specified, fio will "bite" off chunks of
the IO logs and runtime compress them with zlib. This can greatly
reduce the amount of memory required to do iops/bw/lat logging of
a run, at the cost of using some background CPU for the compression.

Signed-off-by: Jens Axboe <axboe@fb.com>
Pass O_DIRECT/O_SYNC to glfs_open if requested.

GlusterFS supports O_DIRECT and O_SYNC.

Signed-off-by: Jens Axboe <axboe@fb.com>
tp: remove debug start/shutdown printfs

Signed-off-by: Jens Axboe <axboe@fb.com>
Bail out if glfs_creat failed

Otherwise we will get segfaults from gfapi when it tries to access the
invalid fd.

Signed-off-by: Jens Axboe <axboe@fb.com>
fio.1 - escape the escape character so it shows up

Hi, Jens,

In the filename= text, the escape character gets eaten.  This fixes it
for me.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>