geom/sched/g_sched.c

30  * $FreeBSD: releng/10.2/sys/geom/sched/g_sched.c 243333 2012-11-20 12:32:18Z jh $
32  * Main control module for geom-based disk schedulers ('sched').
36  * an existing provider pp and its original geom gp
40  * using the command "geom sched insert <provider>" and
45  * Deletion "geom sched destroy <provider>.sched." restores the
46  * original chain. The normal "geom sched create <provide>"
52  *   geom{}         g_sched_softc{}      g_gsched{}
67  * A g_sched_softc{} is created with a "geom sched insert" call.
98  * removed with "geom sched destroy", we need to remove all references
118 #include <geom/geom.h>
120 #include "g_sched.h"		/* geom hooks */
123  * Size of the per-geom hash table storing traffic classes.
372  * a geom and a bio and returns the private descriptor
537 	 * destruction can take place due to the geom topology lock; no
539 	 * geom as being flushed.
663 	LIST_FOREACH_SAFE(gp, &g_sched_class.geom, geom, gp_tmp) {
727 	 * If the module is loaded at boot, the geom thread that calls
795  * g_sched_done() and g_sched_start() dispatch the geom requests to
824 	struct g_geom *gp = bp->bio_to->geom;
887  * The next few functions are the geom glue.
894 	g_sched_destroy(cp->geom, 1);
904 	gp = pp->geom;
945 	saved_start = pp->geom->start;
958 	/* link pp to this geom */
960 	pp->geom = gp;
981  * Create a geom node for the device passed as *pp.
998 	LIST_FOREACH(gp, &mp->geom, geom) {
1007 	dstgp = proxy ? pp->geom : gp; /* where do we link the provider */
1092 	gp = pp->geom;
1156 		pp->geom->start = g_sched_temporary_start;
1182 	pp->geom = gp;
1189 	struct g_geom *gp = oldpp->geom;
1191 	g_reparent_provider(oldpp, newpp->geom, newpp);
1203  * original geom, and destroying the proxy provider.  Also take care
1220 		/* Relink the provider to its original geom. */
1230 		g_sched_flush_pending(oldpp->geom->start);
1315 				    " destroying geom, some memory leaked.");
1336 				    "destroying a proxy geom, leaking some "
1366  * as the bio is posted to the geom queue (and not later, because
1458 	/sys/geom/geom_io.c::g_io_request(), and remove this line.
1589 	cp = LIST_FIRST(&pp->geom->consumer);
1592 	gp = cp->provider->geom;
1639  * this geom is created. Right now this is under control of a kenv
1661 		if (pp->geom->class == mp)
1664 		taste_names = getenv("geom.sched.taste");
1682 		s = getenv("geom.sched.algo");
1777 		if (pp == NULL || pp->geom->class != mp) {
1794 	LIST_FOREACH(gp, &mp->geom, geom) {