Introduce NOP GEOM class. This is totally transparent GEOM class, but

it is very useful for tests. One is able to destroy its provider
forcibly if wants to test how other class handle such events.
One is also able to specify failure probability to check how other
classes handle I/O errors.

Supported by:	Wheel - Open Technologies - http://www.wheel.pl

2 files changed, 478 insertions, 0 deletions

diff --git a/sys/geom/nop/g_nop.c b/sys/geom/nop/g_nop.c
new file mode 100644
index 0000000..63e04c8
--- /dev/null
+++ b/sys/geom/nop/g_nop.c
@@ -0,0 +1,420 @@
+/*-
+ * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/bio.h>
+#include <sys/sysctl.h>
+#include <sys/malloc.h>
+#include <geom/geom.h>
+#include <geom/nop/g_nop.h>
+
+
+SYSCTL_DECL(_kern_geom);
+SYSCTL_NODE(_kern_geom, OID_AUTO, nop, CTLFLAG_RW, 0, "GEOM_NOP stuff");
+static u_int g_nop_debug = 0;
+SYSCTL_UINT(_kern_geom_nop, OID_AUTO, debug, CTLFLAG_RW, &g_nop_debug, 0,
+    "Debug level");
+
+static int g_nop_destroy(struct g_geom *gp, boolean_t force);
+static int g_nop_destroy_geom(struct gctl_req *req, struct g_class *mp,
+    struct g_geom *gp);
+static void g_nop_config(struct gctl_req *req, struct g_class *mp,
+    const char *verb);
+static void g_nop_dumpconf(struct sbuf *sb, const char *indent,
+    struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
+
+struct g_class g_nop_class = {
+	.name = G_NOP_CLASS_NAME,
+	.ctlreq = g_nop_config,
+	.destroy_geom = g_nop_destroy_geom
+};
+
+
+static void
+g_nop_orphan(struct g_consumer *cp)
+{
+
+	g_topology_assert();
+	g_nop_destroy(cp->geom, 1);
+}
+
+static void
+g_nop_start(struct bio *bp)
+{
+	struct g_geom *gp;
+	struct g_provider *pp;
+	struct bio *cbp;
+
+	gp = bp->bio_to->geom;
+	G_NOP_LOGREQ(bp, "Request received.");
+	cbp = g_clone_bio(bp);
+	if (cbp == NULL) {
+		g_io_deliver(bp, ENOMEM);
+		return;
+	}
+	pp = LIST_FIRST(&gp->provider);
+	KASSERT(pp != NULL, ("NULL pp"));
+	if (pp->index > 0) {
+		u_int rval;
+
+		rval = arc4random() % 100;
+		if (rval < pp->index) {
+			g_io_deliver(bp, EIO);
+			return;
+		}
+	}
+	cbp->bio_done = g_std_done;
+	cbp->bio_offset = bp->bio_offset;
+	cbp->bio_data = bp->bio_data;
+	cbp->bio_length = bp->bio_length;
+	cbp->bio_to = LIST_FIRST(&gp->provider);
+	G_NOP_LOGREQ(cbp, "Sending request.");
+	g_io_request(cbp, LIST_FIRST(&gp->consumer));
+}
+
+static int
+g_nop_access(struct g_provider *pp, int dr, int dw, int de)
+{
+	struct g_geom *gp;
+	struct g_consumer *cp;
+	int error;
+
+	gp = pp->geom;
+	cp = LIST_FIRST(&gp->consumer);
+	error = g_access(cp, dr, dw, de);
+
+	return (error);
+}
+
+static int
+g_nop_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
+    u_int failprob)
+{
+	struct g_geom *gp;
+	struct g_provider *newpp;
+	struct g_consumer *cp;
+	int error;
+
+	g_topology_assert();
+
+	gp = NULL;
+	newpp = NULL;
+	cp = NULL;
+
+	gp = g_new_geomf(mp, "%s%s", pp->name, G_NOP_SUFFIX);
+	if (gp == NULL) {
+		gctl_error(req, "Cannot create geom %s%s.", pp->name,
+		    G_NOP_SUFFIX);
+		return (ENOMEM);
+	}
+	gp->softc = NULL;
+	gp->start = g_nop_start;
+	gp->spoiled = g_nop_orphan;
+	gp->orphan = g_nop_orphan;
+	gp->access = g_nop_access;
+	gp->dumpconf = g_nop_dumpconf;
+
+	newpp = g_new_providerf(gp, gp->name);
+	if (newpp == NULL) {
+		gctl_error(req, "Cannot create provider %s%s.", pp->name,
+		    G_NOP_SUFFIX);
+		error = ENOMEM;
+		goto fail;
+	}
+	newpp->mediasize = pp->mediasize;
+	newpp->sectorsize = pp->sectorsize;
+	newpp->index = failprob;
+
+	cp = g_new_consumer(gp);
+	if (cp == NULL) {
+		gctl_error(req, "Cannot create consumer for %s.", gp->name);
+		error = ENOMEM;
+		goto fail;
+	}
+	error = g_attach(cp, pp);
+	if (error != 0) {
+		gctl_error(req, "Cannot attach to provider %s.", pp->name);
+		goto fail;
+	}
+
+	g_error_provider(newpp, 0);
+	G_NOP_DEBUG(0, "Device %s created.", gp->name);
+	return (0);
+fail:
+	if (cp != NULL) {
+		if (cp->provider != NULL)
+			g_detach(cp);
+		g_destroy_consumer(cp);
+	}
+	if (newpp != NULL)
+		g_destroy_provider(pp);
+	if (gp != NULL)
+		g_destroy_geom(gp);
+	return (error);
+}
+
+static int
+g_nop_destroy(struct g_geom *gp, boolean_t force)
+{
+	struct g_provider *pp;
+
+	g_topology_assert();
+	pp = LIST_FIRST(&gp->provider);
+	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
+		if (force) {
+			G_NOP_DEBUG(0, "Device %s is still open, so it "
+			    "can't be definitely removed.", pp->name);
+		} else {
+			G_NOP_DEBUG(1, "Device %s is still open (r%dw%de%d).",
+			    pp->name, pp->acr, pp->acw, pp->ace);
+			return (EBUSY);
+		}
+	} else {
+		G_NOP_DEBUG(0, "Device %s removed.", gp->name);
+	}
+	g_wither_geom(gp, ENXIO);
+
+	return (0);
+}
+
+static int
+g_nop_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
+{
+
+	return (g_nop_destroy(gp, 0));
+}
+
+static void
+g_nop_ctl_create(struct gctl_req *req, struct g_class *mp)
+{
+	struct g_provider *pp;
+	intmax_t *failprob;
+	const char *name;
+	char param[16];
+	int i, *nargs;
+
+	g_topology_assert();
+
+	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
+	if (nargs == NULL) {
+		gctl_error(req, "No '%s' argument", "nargs");
+		return;
+	}
+	if (*nargs <= 0) {
+		gctl_error(req, "Missing device(s).");
+		return;
+	}
+	failprob = gctl_get_paraml(req, "failprob", sizeof(*failprob));
+	if (failprob == NULL) {
+		gctl_error(req, "No '%s' argument", "failprob");
+		return;
+	}
+	if (*failprob < 0 || *failprob > 100) {
+		gctl_error(req, "Invalid '%s' argument", "failprob");
+		return;
+	}
+
+	for (i = 0; i < *nargs; i++) {
+		snprintf(param, sizeof(param), "arg%d", i);
+		name = gctl_get_asciiparam(req, param); 
+		if (name == NULL) {
+			gctl_error(req, "No 'arg%d' argument", i);
+			return;
+		}
+		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
+			name += strlen("/dev/");
+		pp = g_provider_by_name(name);
+		if (pp == NULL) {
+			G_NOP_DEBUG(1, "Provider %s is invalid.", name);
+			gctl_error(req, "Provider %s is invalid.", name);
+			return; 
+		}
+		if (g_nop_create(req, mp, pp, (u_int)*failprob) != 0)
+			return;
+	}
+}
+
+static void
+g_nop_ctl_config(struct gctl_req *req, struct g_class *mp)
+{
+	struct g_provider *pp;
+	intmax_t *failprob;
+	const char *name;
+	char param[16];
+	int i, *nargs;
+
+	g_topology_assert();
+
+	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
+	if (nargs == NULL) {
+		gctl_error(req, "No '%s' argument", "nargs");
+		return;
+	}
+	if (*nargs <= 0) {
+		gctl_error(req, "Missing device(s).");
+		return;
+	}
+	failprob = gctl_get_paraml(req, "failprob", sizeof(*failprob));
+	if (failprob == NULL) {
+		gctl_error(req, "No '%s' argument", "failprob");
+		return;
+	}
+	if (*failprob < 0 || *failprob > 100) {
+		gctl_error(req, "Invalid '%s' argument", "failprob");
+		return;
+	}
+
+	for (i = 0; i < *nargs; i++) {
+		snprintf(param, sizeof(param), "arg%d", i);
+		name = gctl_get_asciiparam(req, param); 
+		if (name == NULL) {
+			gctl_error(req, "No 'arg%d' argument", i);
+			return;
+		}
+		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
+			name += strlen("/dev/");
+		pp = g_provider_by_name(name);
+		if (pp == NULL || pp->geom->class != mp) {
+			G_NOP_DEBUG(1, "Provider %s is invalid.", name);
+			gctl_error(req, "Provider %s is invalid.", name);
+			return; 
+		}
+		pp->index = (u_int)*failprob;
+	}
+}
+
+static struct g_geom *
+g_nop_find_geom(struct g_class *mp, const char *name)
+{
+	struct g_geom *gp;
+
+	LIST_FOREACH(gp, &mp->geom, geom) {
+		if (strcmp(gp->name, name) == 0)
+			return (gp);
+	}
+	return (NULL);
+}
+
+static void
+g_nop_ctl_destroy(struct gctl_req *req, struct g_class *mp)
+{
+	int *nargs, *force, error, i;
+	struct g_geom *gp;
+	const char *name;
+	char param[16];
+
+	g_topology_assert();
+
+	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
+	if (nargs == NULL) {
+		gctl_error(req, "No '%s' argument", "nargs");
+		return;
+	}
+	if (*nargs <= 0) {
+		gctl_error(req, "Missing device(s).");
+		return;
+	}
+	force = gctl_get_paraml(req, "force", sizeof(*force));
+	if (force == NULL) {
+		gctl_error(req, "No 'force' argument");
+		return;
+	}
+
+	for (i = 0; i < *nargs; i++) {
+		snprintf(param, sizeof(param), "arg%d", i);
+		name = gctl_get_asciiparam(req, param); 
+		if (name == NULL) {
+			gctl_error(req, "No 'arg%d' argument", i);
+			return;
+		}
+		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
+			name += strlen("/dev/");
+		gp = g_nop_find_geom(mp, name);
+		if (gp == NULL) {
+			G_NOP_DEBUG(1, "Device %s is invalid.", name);
+			gctl_error(req, "Device %s is invalid.", name);
+			return; 
+		}
+		error = g_nop_destroy(gp, *force);
+		if (error != 0) {
+			gctl_error(req, "Cannot destroy device %s (error=%d).",
+			    gp->name, error);
+			return;
+		}
+	}
+}
+
+static void
+g_nop_config(struct gctl_req *req, struct g_class *mp, const char *verb)
+{
+	uint32_t *version;
+
+	g_topology_assert();
+
+	version = gctl_get_paraml(req, "version", sizeof(*version));
+	if (version == NULL) {
+		gctl_error(req, "No '%s' argument.", "version");
+		return;
+	}
+	if (*version != G_NOP_VERSION) {
+		gctl_error(req, "Userland and kernel parts are out of sync.");
+		return;
+	}
+
+	if (strcmp(verb, "create") == 0) {
+		g_nop_ctl_create(req, mp);
+		return;
+	} else if (strcmp(verb, "config") == 0) {
+		g_nop_ctl_config(req, mp);
+		return;
+	} else if (strcmp(verb, "destroy") == 0) {
+		g_nop_ctl_destroy(req, mp);
+		return;
+	}
+
+	gctl_error(req, "Unknown verb.");
+}
+
+static void
+g_nop_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
+    struct g_consumer *cp, struct g_provider *pp)
+{
+
+	if (pp != NULL) {
+		sbuf_printf(sb, "%s<failprob>%u</failprob>\n", indent,
+		    pp->index);
+	}
+}
+
+DECLARE_GEOM_CLASS(g_nop_class, g_nop);
diff --git a/sys/geom/nop/g_nop.h b/sys/geom/nop/g_nop.h
new file mode 100644
index 0000000..59dbdde
--- /dev/null
+++ b/sys/geom/nop/g_nop.h
@@ -0,0 +1,58 @@
+/*-
+ * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_G_NOP_H_
+#define	_G_NOP_H_
+
+#define	G_NOP_CLASS_NAME	"NOP"
+#define	G_NOP_VERSION		0
+#define	G_NOP_SUFFIX		".nop"
+
+#ifdef _KERNEL
+#define	G_NOP_DEBUG(lvl, ...)	do {					\
+	if (g_nop_debug >= (lvl)) {					\
+		printf("GEOM_NOP");					\
+		if (g_nop_debug > 0)					\
+			printf("[%u]", lvl);				\
+		printf(": ");						\
+		printf(__VA_ARGS__);					\
+		printf("\n");						\
+	}								\
+} while (0)
+#define	G_NOP_LOGREQ(bp, ...)	do {					\
+	if (g_nop_debug >= 2) {						\
+		printf("GEOM_NOP[2]: ");				\
+		printf(__VA_ARGS__);					\
+		printf(" ");						\
+		g_print_bio(bp);					\
+		printf("\n");						\
+	}								\
+} while (0)
+#endif	/* _KERNEL */
+
+#endif	/* _G_NOP_H_ */