First commit of the GEOM subsystem to make it easier for people to

test and play with this.

This is not yet production quality and should be run only on dedicated
test boxes.

For people who want to develop transformations for GEOM there exist a
set of shims to run geom in userland (ask phk@freebsd.org).

Reports of all kinds to: phk@freebsd.org
Please include in report:
        dmesg
        sysctl debug.geomdot
        sysctl debug.geomconf

Known significant limitations:
        no kernel dump facility.
        ioctls severely restricted.

Sponsored by:   DARPA, NAI Labs

1 files changed, 639 insertions, 0 deletions

diff --git a/sys/geom/geom_subr.c b/sys/geom/geom_subr.c
new file mode 100644
index 0000000..a458550
--- /dev/null
+++ b/sys/geom/geom_subr.c
@@ -0,0 +1,639 @@
+/*-
+ * Copyright (c) 2002 Poul-Henning Kamp
+ * Copyright (c) 2002 Networks Associates Technology, Inc.
+ * All rights reserved.
+ *
+ * This software was developed for the FreeBSD Project by Poul-Henning Kamp
+ * and NAI Labs, the Security Research Division of Network Associates, Inc.
+ * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
+ * DARPA CHATS research program.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+
+#include <sys/param.h>
+#ifndef _KERNEL
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <err.h>
+#else
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/bio.h>
+#include <sys/sysctl.h>
+#include <sys/proc.h>
+#include <sys/kthread.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#endif
+#include <sys/errno.h>
+#include <sys/sbuf.h>
+#include <geom/geom.h>
+#include <machine/stdarg.h>
+
+struct method_list_head g_methods = LIST_HEAD_INITIALIZER(g_methods);
+static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
+static int g_nproviders;
+char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
+
+static int g_ignition;
+
+void
+g_add_method(struct g_method *mp)
+{
+
+	if (!g_ignition) {
+		g_ignition++;
+		g_init();
+	}
+	g_topology_lock();
+	g_trace(G_T_TOPOLOGY, "g_add_method(%s)", mp->name);
+	LIST_INIT(&mp->geom);
+	LIST_INSERT_HEAD(&g_methods, mp, method);
+	if (g_nproviders > 0)
+		g_post_event(EV_NEW_METHOD, mp, NULL, NULL, NULL);
+	g_topology_unlock();
+}
+
+struct g_geom *
+g_new_geomf(struct g_method *mp, char *fmt, ...)
+{
+	struct g_geom *gp;
+	va_list ap;
+	struct sbuf *sb;
+
+	g_topology_assert();
+	va_start(ap, fmt);
+	mtx_lock(&Giant);
+	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
+	sbuf_vprintf(sb, fmt, ap);
+	sbuf_finish(sb);
+	mtx_unlock(&Giant);
+	gp = g_malloc(sizeof *gp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
+	gp->name = (char *)(gp + 1);
+	gp->method = mp;
+	gp->rank = 1;
+	LIST_INIT(&gp->consumer);
+	LIST_INIT(&gp->provider);
+	LIST_INSERT_HEAD(&mp->geom, gp, geom);
+	TAILQ_INSERT_HEAD(&geoms, gp, geoms);
+	strcpy(gp->name, sbuf_data(sb));
+	sbuf_delete(sb);
+	return (gp);
+}
+
+void
+g_destroy_geom(struct g_geom *gp)
+{
+
+	g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
+	g_topology_assert();
+	KASSERT(gp->event == NULL, ("g_destroy_geom() with event"));
+	KASSERT(LIST_EMPTY(&gp->consumer),
+	    ("g_destroy_geom(%s) with consumer(s) [%p]",
+	    gp->name, LIST_FIRST(&gp->consumer)));
+	KASSERT(LIST_EMPTY(&gp->provider),
+	    ("g_destroy_geom(%s) with provider(s) [%p]",
+	    gp->name, LIST_FIRST(&gp->consumer)));
+	LIST_REMOVE(gp, geom);
+	TAILQ_REMOVE(&geoms, gp, geoms);
+	g_free(gp);
+}
+
+struct g_consumer *
+g_new_consumer(struct g_geom *gp)
+{
+	struct g_consumer *cp;
+
+	g_topology_assert();
+	KASSERT(gp->method->orphan != NULL,
+	    ("g_new_consumer on method(%s) without orphan", gp->method->name));
+
+	cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
+	cp->geom = gp;
+	LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
+	return(cp);
+}
+
+void
+g_destroy_consumer(struct g_consumer *cp)
+{
+
+	g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
+	g_topology_assert();
+	KASSERT(cp->event == NULL, ("g_destroy_consumer() with event"));
+	KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
+	KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
+	KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
+	KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
+	LIST_REMOVE(cp, consumer);
+	g_free(cp);
+}
+
+struct g_provider *
+g_new_providerf(struct g_geom *gp, char *fmt, ...)
+{
+	struct g_provider *pp;
+	struct sbuf *sb;
+	va_list ap;
+
+	g_topology_assert();
+	va_start(ap, fmt);
+	mtx_lock(&Giant);
+	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
+	sbuf_vprintf(sb, fmt, ap);
+	sbuf_finish(sb);
+	mtx_unlock(&Giant);
+	pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
+	pp->name = (char *)(pp + 1);
+	strcpy(pp->name, sbuf_data(sb));
+	sbuf_delete(sb);
+	LIST_INIT(&pp->consumers);
+	pp->error = ENXIO;
+	pp->geom = gp;
+	LIST_INSERT_HEAD(&gp->provider, pp, provider);
+	g_nproviders++;
+	g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
+	return (pp);
+}
+
+void
+g_error_provider(struct g_provider *pp, int error)
+{
+
+	pp->error = error;
+}
+
+
+void
+g_destroy_provider(struct g_provider *pp)
+{
+	struct g_geom *gp;
+	struct g_consumer *cp;
+
+	g_topology_assert();
+	KASSERT(pp->event == NULL, ("g_destroy_provider() with event"));
+	KASSERT(LIST_EMPTY(&pp->consumers),
+	    ("g_destroy_provider but attached"));
+	KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
+	KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
+	KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
+	g_nproviders--;
+	LIST_REMOVE(pp, provider);
+	gp = pp->geom;
+	g_free(pp);
+	if (!(gp->flags & G_GEOM_WITHER))
+		return;
+	if (!LIST_EMPTY(&gp->provider))
+		return;
+	for (;;) {
+		cp = LIST_FIRST(&gp->consumer);
+		if (cp == NULL)
+			break;
+		g_dettach(cp);
+		g_destroy_consumer(cp);
+	}
+	g_destroy_geom(gp);
+}
+
+/*
+ * We keep the "geoms" list sorted by topological order (== increasing
+ * numerical rank) at all times.
+ * When an attach is done, the attaching geoms rank is invalidated
+ * and it is moved to the tail of the list.
+ * All geoms later in the sequence has their ranks reevaluated in
+ * sequence.  If we cannot assign rank to a geom because it's
+ * prerequisites do not have rank, we move that element to the tail
+ * of the sequence with invalid rank as well.
+ * At some point we encounter our original geom and if we stil fail
+ * to assign it a rank, there must be a loop and we fail back to
+ * g_attach() which dettach again and calls redo_rank again
+ * to fix up the damage.
+ * It would be much simpler code wise to do it recursively, but we
+ * can't risk that on the kernel stack.
+ */
+
+static int
+redo_rank(struct g_geom *gp)
+{
+	struct g_consumer *cp;
+	struct g_geom *gp1, *gp2;
+	int n, m;
+
+	g_topology_assert();
+
+	/* Invalidate this geoms rank and move it to the tail */
+	gp1 = TAILQ_NEXT(gp, geoms);
+	if (gp1 != NULL) {
+		gp->rank = 0;
+		TAILQ_REMOVE(&geoms, gp, geoms);
+		TAILQ_INSERT_TAIL(&geoms, gp, geoms);
+	} else {
+		gp1 = gp;
+	}
+
+	/* re-rank the rest of the sequence */
+	for (; gp1 != NULL; gp1 = gp2) {
+		gp1->rank = 0;
+		m = 1;
+		LIST_FOREACH(cp, &gp1->consumer, consumer) {
+			if (cp->provider == NULL)
+				continue;
+			n = cp->provider->geom->rank;
+			if (n == 0) {
+				m = 0;
+				break;
+			} else if (n >= m)
+				m = n + 1;
+		}
+		gp1->rank = m;
+		gp2 = TAILQ_NEXT(gp1, geoms);
+
+		/* got a rank, moving on */
+		if (m != 0)
+			continue;
+
+		/* no rank to original geom means loop */
+		if (gp == gp1) {
+			return (ELOOP);
+
+		/* no rank, put it at the end move on */
+		TAILQ_REMOVE(&geoms, gp1, geoms);
+		TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
+		}
+	}
+	return (0);
+}
+
+int
+g_attach(struct g_consumer *cp, struct g_provider *pp)
+{
+	int error;
+
+	g_topology_assert();
+	KASSERT(cp->provider == NULL, ("attach but attached"));
+	cp->provider = pp;
+	LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
+	error = redo_rank(cp->geom);
+	if (error) {
+		LIST_REMOVE(cp, consumers);
+		cp->provider = NULL;
+		redo_rank(cp->geom);
+	}
+	return (error);
+}
+
+void
+g_dettach(struct g_consumer *cp)
+{
+	struct g_provider *pp;
+
+	g_trace(G_T_TOPOLOGY, "g_dettach(%p)", cp);
+	KASSERT(cp != (void*)0xd0d0d0d0, ("ARGH!"));
+	g_topology_assert();
+	KASSERT(cp->provider != NULL, ("dettach but not attached"));
+	KASSERT(cp->acr == 0, ("dettach but nonzero acr"));
+	KASSERT(cp->acw == 0, ("dettach but nonzero acw"));
+	KASSERT(cp->ace == 0, ("dettach but nonzero ace"));
+	KASSERT(cp->biocount == 0, ("dettach but nonzero biocount"));
+	pp = cp->provider;
+	LIST_REMOVE(cp, consumers);
+	cp->provider = NULL;
+	if (LIST_EMPTY(&pp->consumers)) {
+		if (pp->geom->flags & G_GEOM_WITHER)
+			g_destroy_provider(pp);
+	}
+	redo_rank(cp->geom);
+}
+
+
+/*
+ * g_access_abs()
+ *
+ * Access-check with absolute new values:  Just fall through
+ * and use the relative version.
+ */
+int
+g_access_abs(struct g_consumer *cp, int acr, int acw, int ace)
+{
+
+	g_topology_assert();
+	return(g_access_rel(cp,
+		acr - cp->acr,
+		acw - cp->acw,
+		ace - cp->ace));
+}
+
+/*
+ * g_access_rel()
+ *
+ * Access-check with delta values.  The question asked is "can provider
+ * "cp" change the access counters by the relative amounts dc[rwe] ?"
+ */
+
+int
+g_access_rel(struct g_consumer *cp, int dcr, int dcw, int dce)
+{
+	struct g_provider *pp;
+	int pr,pw,pe;
+	int error;
+
+	pp = cp->provider;
+
+	g_trace(G_T_ACCESS, "g_access_rel(%p(%s), %d, %d, %d)",
+	    cp, pp->name, dcr, dcw, dce);
+
+	g_topology_assert();
+	KASSERT(cp->provider != NULL, ("access but not attached"));
+	KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
+	KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
+	KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
+	KASSERT(pp->geom->method->access != NULL, ("NULL method->access"));
+
+	/*
+	 * If our method cares about being spoiled, and we have been, we
+	 * are probably just ahead of the event telling us that.  Fail
+	 * now rather than having to unravel this later.
+	 */
+	if (cp->geom->spoiled != NULL && cp->spoiled) {
+		KASSERT(dcr >= 0, ("spoiled but dcr = %d", dcr));
+		KASSERT(dcw >= 0, ("spoiled but dce = %d", dcw));
+		KASSERT(dce >= 0, ("spoiled but dcw = %d", dce));
+		KASSERT(cp->acr == 0, ("spoiled but cp->acr = %d", cp->acr));
+		KASSERT(cp->acw == 0, ("spoiled but cp->acw = %d", cp->acw));
+		KASSERT(cp->ace == 0, ("spoiled but cp->ace = %d", cp->ace));
+		return(ENXIO);
+	}
+
+	/*
+	 * Figure out what counts the provider would have had, if this
+	 * consumer had (r0w0e0) at this time.
+	 */
+	pr = pp->acr - cp->acr;
+	pw = pp->acw - cp->acw;
+	pe = pp->ace - cp->ace;
+
+	g_trace(G_T_ACCESS,
+    "open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
+	    dcr, dcw, dce,
+	    cp->acr, cp->acw, cp->ace,
+	    pp->acr, pp->acw, pp->ace,
+	    pp, pp->name);
+
+	/* If we try exclusive but already write: fail */
+	if (dce > 0 && pw > 0)
+		return (EPERM);
+	/* If we try write but already exclusive: fail */
+	if (dcw > 0 && pe > 0)
+		return (EPERM);
+	/* If we try to open more but provider is error'ed: fail */
+	if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
+		return (pp->error);
+
+	/* Ok then... */
+
+	/*
+	 * If we open first write, spoil any partner consumers.
+	 * If we close last write, trigger re-taste.
+	 */
+	if (pp->acw == 0 && dcw != 0)
+		g_spoil(pp, cp);
+	else if (pp->acw != 0 && pp->acw == -dcw && !(pp->geom->flags & G_GEOM_WITHER))
+		g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
+
+	error = pp->geom->method->access(pp, dcr, dcw, dce);
+	if (!error) {
+		pp->acr += dcr;
+		pp->acw += dcw;
+		pp->ace += dce;
+		cp->acr += dcr;
+		cp->acw += dcw;
+		cp->ace += dce;
+	}
+	return (error);
+}
+
+int
+g_haveattr_int(struct bio *bp, char *attribute, int val)
+{
+
+	return (g_haveattr(bp, attribute, &val, sizeof val));
+}
+
+int
+g_haveattr_off_t(struct bio *bp, char *attribute, off_t val)
+{
+
+	return (g_haveattr(bp, attribute, &val, sizeof val));
+}
+
+
+int
+g_haveattr(struct bio *bp, char *attribute, void *val, int len)
+{
+	int error;
+
+	if (strcmp(bp->bio_attribute, attribute))
+		return (0);
+	if (bp->bio_length != len) {
+		printf("bio_length %lld len %d -> EFAULT\n", bp->bio_length, len);
+		error = EFAULT;
+	} else {
+		error = 0;
+		bcopy(val, bp->bio_data, len);
+		bp->bio_completed = len;
+	}
+	bp->bio_error = error;
+	g_io_deliver(bp);
+	return (1);
+}
+
+int
+g_std_access(struct g_provider *pp __unused,
+	int dr __unused, int dw __unused, int de __unused)
+{
+
+        return (0);
+}
+
+void
+g_std_done(struct bio *bp)
+{
+	struct bio *bp2;
+
+	bp2 = bp->bio_linkage;
+	bp2->bio_error = bp->bio_error;
+	bp2->bio_completed = bp->bio_completed;
+	g_destroy_bio(bp);
+	g_io_deliver(bp2);
+}
+
+/* XXX: maybe this is only g_slice_spoiled */
+
+void
+g_std_spoiled(struct g_consumer *cp)
+{
+	struct g_geom *gp;
+	struct g_provider *pp;
+
+	g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
+	g_topology_assert();
+	g_dettach(cp);
+	gp = cp->geom;
+	LIST_FOREACH(pp, &gp->provider, provider)
+		g_orphan_provider(pp, ENXIO);
+	g_destroy_consumer(cp);
+	if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
+		g_destroy_geom(gp);
+	else
+		gp->flags |= G_GEOM_WITHER;
+}
+
+/*
+ * Spoiling happens when a provider is opened for writing, but consumers
+ * which are configured by in-band data are attached (slicers for instance).
+ * Since the write might potentially change the in-band data, such consumers
+ * need to re-evaluate their existence after the writing session closes.
+ * We do this by (offering to) tear them down when the open for write happens
+ * in return for a re-taste when it closes again.
+ * Together with the fact that such consumers grab an 'e' bit whenever they
+ * are open, regardless of mode, this ends up DTRT.
+ */
+
+void
+g_spoil(struct g_provider *pp, struct g_consumer *cp)
+{
+	struct g_consumer *cp2;
+
+	g_topology_assert();
+
+	LIST_FOREACH(cp2, &pp->consumers, consumers) {
+		if (cp2 == cp)
+			continue;
+/*
+		KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
+		KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
+*/
+		KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
+		cp2->spoiled++;
+	}
+	g_post_event(EV_SPOILED, NULL, NULL, pp, cp);
+}
+
+static struct g_method *
+g_method_by_name(char *name)
+{
+	struct g_method *mp;
+
+	g_trace(G_T_TOPOLOGY, "g_method_by_name(%s)", name);
+	g_topology_assert();
+	LIST_FOREACH(mp, &g_methods, method)
+		if (!strcmp(mp->name, name))
+			return (mp);
+	return (NULL);
+}
+
+struct g_geom *
+g_create_geomf(char *method, struct g_provider *pp, char *fmt, ...)
+{
+	va_list ap;
+	struct sbuf *sb;
+	char *s;
+	struct g_method *mp;
+	struct g_geom *gp;
+
+	g_trace(G_T_TOPOLOGY, "g_create_geom(%s, %p(%s))", method,
+		pp, pp == NULL ? "" : pp->name);
+	g_topology_assert();
+	gp = NULL;
+	mp = g_method_by_name(method);
+	if (mp == NULL)
+		return (NULL);
+	if (fmt != NULL) {
+		va_start(ap, fmt);
+		mtx_lock(&Giant);
+		sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
+		sbuf_vprintf(sb, fmt, ap);
+		sbuf_finish(sb);
+		mtx_unlock(&Giant);
+		s = sbuf_data(sb);
+	} else {
+		s = NULL;
+	}
+	if (pp != NULL)
+		gp = mp->taste(mp, pp, NULL, G_TF_INSIST);
+	if (gp == NULL && mp->create_geom == NULL)
+		return (NULL);
+	if (gp == NULL)
+		gp = mp->create_geom(mp, pp, s);
+	/* XXX: delete sbuf  */
+	return (gp);
+}
+
+struct g_geom *
+g_insert_geom(char *method, struct g_consumer *cp)
+{
+	struct g_method *mp;
+	struct g_geom *gp;
+	struct g_provider *pp, *pp2;
+	struct g_consumer *cp2;
+	int error;
+
+	g_trace(G_T_TOPOLOGY, "g_insert_geomf(%s, %p)", method, cp);
+	g_topology_assert();
+	KASSERT(cp->provider != NULL, ("g_insert_geomf but not attached"));
+	/* XXX: check for events ?? */
+	mp = g_method_by_name(method);
+	if (mp == NULL)
+		return (NULL);
+	if (mp->create_geom == NULL)
+		return (NULL);
+	pp = cp->provider;
+	gp = mp->taste(mp, pp, NULL, G_TF_TRANSPARENT);
+	if (gp == NULL)
+		return (NULL);
+	pp2 = LIST_FIRST(&gp->provider);
+	cp2 = LIST_FIRST(&gp->consumer);
+	cp2->acr += pp->acr;
+	cp2->acw += pp->acw;
+	cp2->ace += pp->ace;
+	pp2->acr += pp->acr;
+	pp2->acw += pp->acw;
+	pp2->ace += pp->ace;
+	LIST_REMOVE(cp, consumers);
+	LIST_INSERT_HEAD(&pp2->consumers, cp, consumers);
+	cp->provider = pp2;
+	error = redo_rank(gp);
+	KASSERT(error == 0, ("redo_rank failed in g_insert_geom"));
+	return (gp);
+}
+