block/gluster: add support for selecting debug logging level
This adds commandline support for the logging level of the
gluster protocol driver, output to stdout. The option is 'debug',
e.g.:
-drive filename=gluster://192.168.15.180/gv2/test.qcow2,debug=9
Debug levels are 0-9, with 9 being the most verbose, and 0 representing
no debugging output. The default is the same as it was before, which
is a level of 4. The current logging levels defined in the gluster
source are:
0 - None
1 - Emergency
2 - Alert
3 - Critical
4 - Error
5 - Warning
6 - Notice
7 - Info
8 - Debug
9 - Trace
(From: glusterfs/logging.h)
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>