Simplify the ioctl handling in GEOM.

This replaces the current ioctl processing with a direct call path
from geom_dev() where the ioctl arrives (from SPECFS) to any directly
connected GEOM class.

The inverse of the above is no longer supported.  This is the
situation were you have one or more intervening GEOM classes, for
instance a BSDlabel on top of a MBR or PC98.  If you want to issue
MBR or PC98 specific ioctls, you will need to issue them on a MBR
or PC98 providers.

This paves the way for inviting CD's, FD's and other special cases
inside GEOM.

1 files changed, 21 insertions, 53 deletions

diff --git a/sys/geom/geom_mbr.c b/sys/geom/geom_mbr.c
index 7d5994a..877f090 100644
--- a/sys/geom/geom_mbr.c
+++ b/sys/geom/geom_mbr.c
@@ -152,42 +152,36 @@ g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0)
 	return (0);
 }
 
-static void
-g_mbr_ioctl(void *arg, int flag)
+static int
+g_mbr_ioctl(struct g_provider *pp, u_long cmd, void *data, struct thread *td)
 {
-	struct bio *bp;
 	struct g_geom *gp;
-	struct g_slicer *gsp;
 	struct g_mbr_softc *ms;
-	struct g_ioctl *gio;
+	struct g_slicer *gsp;
 	struct g_consumer *cp;
-	u_char *sec0;
 	int error;
 
-	bp = arg;
-	if (flag == EV_CANCEL) {
-		g_io_deliver(bp, ENXIO);
-		return;
-	}
-	gp = bp->bio_to->geom;
+	gp = pp->geom;
 	gsp = gp->softc;
 	ms = gsp->softc;
-	gio = (struct g_ioctl *)bp->bio_data;
 
-	/* The disklabel to set is the ioctl argument. */
-	sec0 = gio->data;
-
-	error = g_mbr_modify(gp, ms, sec0);
-	if (error) {
-		g_io_deliver(bp, error);
-		return;
+	switch(cmd) {
+	case DIOCSMBR: {
+		DROP_GIANT();
+		g_topology_lock();
+		/* Validate and modify our slicer instance to match. */
+		error = g_mbr_modify(gp, ms, data);
+		cp = LIST_FIRST(&gp->consumer);
+		error = g_write_data(cp, 0, data, 512);
+		g_topology_unlock();
+		PICKUP_GIANT();
+		return(error);
+	}
+	default:
+		return (ENOIOCTL);
 	}
-	cp = LIST_FIRST(&gp->consumer);
-	error = g_write_data(cp, 0, sec0, 512);
-	g_io_deliver(bp, error);
 }
 
-
 static int
 g_mbr_start(struct bio *bp)
 {
@@ -195,8 +189,7 @@ g_mbr_start(struct bio *bp)
 	struct g_geom *gp;
 	struct g_mbr_softc *mp;
 	struct g_slicer *gsp;
-	struct g_ioctl *gio;
-	int idx, error;
+	int idx;
 
 	pp = bp->bio_to;
 	idx = pp->index;
@@ -211,33 +204,7 @@ g_mbr_start(struct bio *bp)
 			return (1);
 	}
 
-	/* We only handle ioctl(2) requests of the right format. */
-	if (strcmp(bp->bio_attribute, "GEOM::ioctl"))
-		return (0);
-	else if (bp->bio_length != sizeof(*gio))
-		return (0);
-
-	/* Get hold of the ioctl parameters. */
-	gio = (struct g_ioctl *)bp->bio_data;
-
-	switch (gio->cmd) {
-	case DIOCSMBR:
-		/*
-		 * These we cannot do without the topology lock and some
-		 * some I/O requests.  Ask the event-handler to schedule
-		 * us in a less restricted environment.
-		 */
-		error = g_post_event(g_mbr_ioctl, bp, M_NOWAIT, gp, NULL);
-		if (error)
-			g_io_deliver(bp, error);
-		/*
-		 * We must return non-zero to indicate that we will deal
-		 * with this bio, even though we have not done so yet.
-		 */
-		return (1);
-	default:
-		return (0);
-	}
+	return (0);
 }
 
 static void
@@ -275,6 +242,7 @@ g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
 		return (NULL);
 	g_topology_unlock();
 	gp->dumpconf = g_mbr_dumpconf;
+	gp->ioctl = g_mbr_ioctl;
 	do {
 		if (gp->rank != 2 && insist == 0)
 			break;