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, 76 insertions, 139 deletions

diff --git a/sys/geom/geom_bsd.c b/sys/geom/geom_bsd.c
index 4f4d565..1a309eb 100644
--- a/sys/geom/geom_bsd.c
+++ b/sys/geom/geom_bsd.c
@@ -267,98 +267,6 @@ g_bsd_writelabel(struct g_geom *gp, u_char *bootcode)
 	return(error);
 }
 
-
-/*
- * Implement certain ioctls to modify disklabels with.  This function
- * is called by the event handler thread with topology locked as result
- * of the g_post_event() in g_bsd_start().  It is not necessary to keep
- * topology locked all the time but make sure to return with topology
- * locked as well.
- */
-
-static void
-g_bsd_ioctl(void *arg, int flag)
-{
-	struct bio *bp;
-	struct g_geom *gp;
-	struct g_ioctl *gio;
-	u_char *label;
-	int error;
-
-	g_topology_assert();
-	bp = arg;
-	if (flag == EV_CANCEL) {
-		g_io_deliver(bp, ENXIO);
-		return;
-	}
-
-	gp = bp->bio_to->geom;
-	gio = (struct g_ioctl *)bp->bio_data;
-
-	label = g_malloc(LABELSIZE, M_WAITOK);
-
-	/* The disklabel to set is the ioctl argument. */
-	bsd_disklabel_le_enc(label, gio->data);
-
-	/* Validate and modify our slice instance to match. */
-	error = g_bsd_modify(gp, label);	/* Picks up topology lock on success. */
-	g_free(label);
-	if (error || gio->cmd == DIOCSDINFO) {
-		g_io_deliver(bp, error);
-		return;
-	}
-	
-	KASSERT(gio->cmd == DIOCWDINFO, ("Unknown ioctl in g_bsd_ioctl"));
-	g_io_deliver(bp, g_bsd_writelabel(gp, NULL));
-}
-
-/*
- * Rewrite the bootblock, which is BBSIZE bytes from the start of the disk.
- * We punch down the disklabel where we expect it to be before writing.
- */
-static int
-g_bsd_diocbsdbb(dev_t dev, u_long cmd __unused, caddr_t data, int fflag __unused, struct thread *td __unused)
-{
-	struct g_geom *gp;
-	struct g_slicer *gsp;
-	struct g_bsd_softc *ms;
-	struct g_consumer *cp;
-	u_char *buf;
-	void *p;
-	int error, i;
-	uint64_t sum;
-
-	/* Get hold of the interesting bits from the bio. */
-	gp = (void *)dev;
-	gsp = gp->softc;
-	ms = gsp->softc;
-
-	/* The disklabel to set is the ioctl argument. */
-	buf = g_malloc(BBSIZE, M_WAITOK);
-	p = *(void **)data;
-	error = copyin(p, buf, BBSIZE);
-	if (!error) {
-		DROP_GIANT();
-		g_topology_lock();
-		/* Validate and modify our slice instance to match. */
-		error = g_bsd_modify(gp, buf + ms->labeloffset);
-		if (!error) {
-			cp = LIST_FIRST(&gp->consumer);
-			if (ms->labeloffset == ALPHA_LABEL_OFFSET) {
-				sum = 0;
-				for (i = 0; i < 63; i++)
-					sum += le64dec(buf + i * 8);
-				le64enc(buf + 504, sum);
-			}
-			error = g_write_data(cp, 0, buf, BBSIZE);
-		}
-		g_topology_unlock();
-		PICKUP_GIANT();
-	}
-	g_free(buf);
-	return (error);
-}
-
 /*
  * If the user tries to overwrite our disklabel through an open partition
  * or via a magicwrite config call, we end up here and try to prevent
@@ -406,70 +314,98 @@ g_bsd_hotwrite(void *arg, int flag)
  *    * Don't grab the topology lock.
  *    * Don't call biowait, g_getattr(), g_setattr() or g_read_data()
  */
-
 static int
-g_bsd_start(struct bio *bp)
+g_bsd_ioctl(struct g_provider *pp, u_long cmd, void * data, struct thread *td)
 {
 	struct g_geom *gp;
 	struct g_bsd_softc *ms;
 	struct g_slicer *gsp;
-	struct g_ioctl *gio;
+	u_char *label;
 	int error;
 
-	gp = bp->bio_to->geom;
+	gp = pp->geom;
 	gsp = gp->softc;
 	ms = gsp->softc;
-	switch(bp->bio_cmd) {
-	case BIO_GETATTR:
-		if (g_handleattr(bp, "BSD::labelsum", ms->labelsum,
-		    sizeof(ms->labelsum)))
-			return (1);
-		break;
-	default:
-		KASSERT(0 == 1, ("Unknown bio_cmd in g_bsd_start (%d)",
-		    bp->bio_cmd));
-	}
-
-	/* 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) {
+	switch(cmd) {
 	case DIOCGDINFO:
 		/* Return a copy of the disklabel to userland. */
-		bsd_disklabel_le_dec(ms->label, gio->data, MAXPARTITIONS);
-		g_io_deliver(bp, 0);
-		return (1);
-	case DIOCBSDBB:
-		gio->func = g_bsd_diocbsdbb;
-		gio->dev = (void *)gp;
-		g_io_deliver(bp, EDIRIOCTL);
-		return (1);
+		bsd_disklabel_le_dec(ms->label, data, MAXPARTITIONS);
+		return(0);
+	case DIOCBSDBB: {
+		struct g_consumer *cp;
+		u_char *buf;
+		void *p;
+		int error, i;
+		uint64_t sum;
+
+		/* The disklabel to set is the ioctl argument. */
+		buf = g_malloc(BBSIZE, M_WAITOK);
+		p = *(void **)data;
+		error = copyin(p, buf, BBSIZE);
+		if (!error) {
+			/* XXX: Rude, but supposedly safe */
+			DROP_GIANT();
+			g_topology_lock();
+			/* Validate and modify our slice instance to match. */
+			error = g_bsd_modify(gp, buf + ms->labeloffset);
+			if (!error) {
+				cp = LIST_FIRST(&gp->consumer);
+				if (ms->labeloffset == ALPHA_LABEL_OFFSET) {
+					sum = 0;
+					for (i = 0; i < 63; i++)
+						sum += le64dec(buf + i * 8);
+					le64enc(buf + 504, sum);
+				}
+				error = g_write_data(cp, 0, buf, BBSIZE);
+			}
+			g_topology_unlock();
+			PICKUP_GIANT();
+		}
+		g_free(buf);
+		return (error);
+	}
 	case DIOCSDINFO:
-	case DIOCWDINFO:
-		/*
-		 * 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_bsd_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);
+	case DIOCWDINFO: {
+		label = g_malloc(LABELSIZE, M_WAITOK);
+
+		/* The disklabel to set is the ioctl argument. */
+		bsd_disklabel_le_enc(label, data);
+
+		DROP_GIANT();
+		g_topology_lock();
+		/* Validate and modify our slice instance to match. */
+		error = g_bsd_modify(gp, label);
+		if (error == 0 && cmd == DIOCWDINFO)
+			error = g_bsd_writelabel(gp, NULL);
+		g_topology_unlock();
+		PICKUP_GIANT();
+		g_free(label);
+		return(error);
+	}
 	default:
-		return (0);
+		return (ENOIOCTL);
 	}
 }
 
+static int
+g_bsd_start(struct bio *bp)
+{
+	struct g_geom *gp;
+	struct g_bsd_softc *ms;
+	struct g_slicer *gsp;
+
+	gp = bp->bio_to->geom;
+	gsp = gp->softc;
+	ms = gsp->softc;
+	if (bp->bio_cmd == BIO_GETATTR) {
+		if (g_handleattr(bp, "BSD::labelsum", ms->labelsum,
+		    sizeof(ms->labelsum)))
+			return (1);
+	}
+	return (0);
+}
+
 /*
  * Dump configuration information in XML format.
  * Notice that the function is called once for the geom and once for each
@@ -559,6 +495,7 @@ g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags)
 	 * routine which the "slice" code should call at the right time
 	 */
 	gp->dumpconf = g_bsd_dumpconf;
+	gp->ioctl = g_bsd_ioctl;
 
 	/* Get the geom_slicer softc from the geom. */
 	gsp = gp->softc;