Rework CTL frontend & backend options to use nv(3), allow creating multiple

ioctl frontend ports.

This revision introduces two changes to CTL:
- Changes the way options are passed to CTL_LUN_REQ and CTL_PORT_REQ ioctls.
  Removes ctl_be_arg structure and associated logic and replaces it with
  nv(3)-based logic for passing in and out arguments.
- Allows creating multiple ioctl frontend ports using either ctladm(8) or
  ctld(8).
  New frontend ports are represented by /dev/cam/ctl<pp>.<vp> nodes, eg /dev/cam/ctl5.3.
  Those device nodes respond only to CTL_IO ioctl.

New command-line options for ctladm:
# creates new ioctl frontend port with using free pp and vp=0
ctladm port -c
# creates new ioctl frontend port with pp=10 and vp=0
ctladm port -c -O pp=10
# creates new ioctl frontend port with pp=11 and vp=12
ctladm port -c -O pp=11 -O vp=12
# removes port with number 4 (it's a "targ_port" number, not pp number)
ctladm port -r -p 4

New syntax for ctl.conf:
target ... {
    port ioctl/<pp>
    ...
}

target ... {
    port ioctl/<pp>/<vp>
    ...

Note: Most of this work was made by jceel@, thank you.

Submitted by:	jceel
Reworked by:	myself
Reviewed by:	mav (earlier versions and recently during the rework)
Obtained from:  FreeNAS and TrueOS
Relnotes:	Yes
Sponsored by:	iXsystems Inc.
Differential Revision:	https://reviews.freebsd.org/D9299

1 files changed, 6 insertions, 4 deletions

diff --git a/sys/cam/ctl/ctl_frontend.c b/sys/cam/ctl/ctl_frontend.c
index 9a206d0c1423..d481c1b8f003 100644
--- a/sys/cam/ctl/ctl_frontend.c
+++ b/sys/cam/ctl/ctl_frontend.c
@@ -52,6 +52,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/endian.h>
 #include <sys/queue.h>
 #include <sys/sysctl.h>
+#include <sys/nv.h>
+#include <sys/dnv.h>
 
 #include <cam/scsi/scsi_all.h>
 #include <cam/scsi/scsi_da.h>
@@ -200,8 +202,8 @@ error:
 	}
 	port->targ_port = port_num;
 	port->ctl_pool_ref = pool;
-	if (port->options.stqh_first == NULL)
-		STAILQ_INIT(&port->options);
+	if (port->options == NULL)
+		port->options = nvlist_create(0);
 	port->stats.item = port_num;
 	mtx_init(&port->port_lock, "CTL port", NULL, MTX_DEF);
 
@@ -240,7 +242,7 @@ ctl_port_deregister(struct ctl_port *port)
 	mtx_unlock(&softc->ctl_lock);
 
 	ctl_pool_free(pool);
-	ctl_free_opts(&port->options);
+	nvlist_destroy(port->options);
 
 	ctl_lun_map_deinit(port);
 	free(port->port_devid, M_CTL);
@@ -333,7 +335,7 @@ ctl_port_online(struct ctl_port *port)
 		port->port_online(port->onoff_arg);
 	mtx_lock(&softc->ctl_lock);
 	if (softc->is_single == 0) {
-		value = ctl_get_opt(&port->options, "ha_shared");
+		value = dnvlist_get_string(port->options, "ha_shared", NULL);
 		if (value != NULL && strcmp(value, "on") == 0)
 			port->status |= CTL_PORT_STATUS_HA_SHARED;
 		else