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, 375 insertions, 0 deletions

diff --git a/sys/geom/geom_io.c b/sys/geom/geom_io.c
new file mode 100644
index 0000000..c43e568
--- /dev/null
+++ b/sys/geom/geom_io.c
@@ -0,0 +1,375 @@
+/*-
+ * 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 <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <err.h>
+#include <sched.h>
+#else
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/bio.h>
+#endif
+
+#include <sys/errno.h>
+#include <geom/geom.h>
+
+static struct g_bioq g_bio_run_down;
+static struct g_bioq g_bio_run_up;
+static struct g_bioq g_bio_idle;
+
+#include <machine/atomic.h>
+
+static void
+g_bioq_lock(struct g_bioq *bq)
+{
+
+	mtx_lock(&bq->bio_queue_lock);
+}
+
+static void
+g_bioq_unlock(struct g_bioq *bq)
+{
+
+	mtx_unlock(&bq->bio_queue_lock);
+}
+
+#if 0
+static void
+g_bioq_destroy(struct g_bioq *bq)
+{
+
+	mtx_destroy(&bq->bio_queue_lock);
+}
+#endif
+
+static void
+g_bioq_init(struct g_bioq *bq)
+{
+
+	TAILQ_INIT(&bq->bio_queue);
+	mtx_init(&bq->bio_queue_lock, "bio queue", MTX_DEF);
+}
+
+static struct bio *
+g_bioq_first(struct g_bioq *bq)
+{
+	struct bio *bp;
+
+	g_bioq_lock(bq);
+	bp = TAILQ_FIRST(&bq->bio_queue);
+	if (bp != NULL) {
+		TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
+		bq->bio_queue_length--;
+	}
+	g_bioq_unlock(bq);
+	return (bp);
+}
+
+static void
+g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
+{
+
+	g_bioq_lock(rq);
+	TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
+	rq->bio_queue_length++;
+	g_bioq_unlock(rq);
+}
+
+struct bio *
+g_new_bio(void)
+{
+	struct bio *bp;
+
+	bp = g_bioq_first(&g_bio_idle);
+	if (bp == NULL)
+		bp = g_malloc(sizeof *bp, M_WAITOK | M_ZERO);
+	g_trace(G_T_BIO, "g_new_bio() = %p", bp);
+	return (bp);
+}
+
+void
+g_destroy_bio(struct bio *bp)
+{
+
+	g_trace(G_T_BIO, "g_destroy_bio(%p)", bp);
+	bzero(bp, sizeof *bp);
+	g_bioq_enqueue_tail(bp, &g_bio_idle);
+}
+
+struct bio *
+g_clone_bio(struct bio *bp)
+{
+	struct bio *bp2;
+
+	bp2 = g_new_bio();
+	bp2->bio_linkage = bp;
+	bp2->bio_cmd = bp->bio_cmd;
+	bp2->bio_length = bp->bio_length;
+	bp2->bio_offset = bp->bio_offset;
+	bp2->bio_data = bp->bio_data;
+	bp2->bio_attribute = bp->bio_attribute;
+	g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2);
+	return(bp2);
+}
+
+void
+g_io_init()
+{
+
+	g_bioq_init(&g_bio_run_down);
+	g_bioq_init(&g_bio_run_up);
+	g_bioq_init(&g_bio_idle);
+}
+
+int
+g_io_setattr(char *attr, struct g_consumer *cp, int len, void *ptr, struct thread *tp __unused)
+{
+	struct bio *bp;
+	int error;
+
+	g_trace(G_T_BIO, "bio_setattr(%s)", attr);
+	do {
+		bp = g_new_bio();
+		bp->bio_cmd = BIO_SETATTR;
+		bp->bio_done = NULL;
+		bp->bio_attribute = attr;
+		bp->bio_length = len;
+		bp->bio_data = ptr;
+		g_io_request(bp, cp);
+		while ((bp->bio_flags & BIO_DONE) == 0) {
+			mtx_lock(&Giant);
+			tsleep(bp, 0, "setattr", hz / 10);
+			mtx_unlock(&Giant);
+		}
+		error = bp->bio_error;
+		g_destroy_bio(bp);
+		if (error == EBUSY)
+			tsleep(&error, 0, "setattr_busy", hz);
+	} while(error == EBUSY);
+	return (error);
+}
+
+
+int
+g_io_getattr(char *attr, struct g_consumer *cp, int *len, void *ptr, struct thread *tp __unused)
+{
+	struct bio *bp;
+	int error;
+
+	g_trace(G_T_BIO, "bio_getattr(%s)", attr);
+	do {
+		bp = g_new_bio();
+		bp->bio_cmd = BIO_GETATTR;
+		bp->bio_done = NULL;
+		bp->bio_attribute = attr;
+		bp->bio_length = *len;
+		bp->bio_data = ptr;
+		g_io_request(bp, cp);
+		while ((bp->bio_flags & BIO_DONE) == 0) {
+			mtx_lock(&Giant);
+			tsleep(bp, 0, "getattr", hz / 10);
+			mtx_unlock(&Giant);
+		}
+		*len = bp->bio_completed;
+		error = bp->bio_error;
+		g_destroy_bio(bp);
+		if (error == EBUSY)
+			tsleep(&error, 0, "getattr_busy", hz);
+
+	} while(error == EBUSY);
+	return (error);
+}
+
+void
+g_io_request(struct bio *bp, struct g_consumer *cp)
+{
+	int error;
+
+	KASSERT(cp != NULL, ("bio_request on thin air"));
+	error = 0;
+	bp->bio_from = cp;
+	bp->bio_to = cp->provider;
+
+	/* begin_stats(&bp->stats); */
+
+	atomic_add_int(&cp->biocount, 1);
+	if (bp->bio_to == NULL)
+		error = ENXIO;
+	if (!error) {
+		switch(bp->bio_cmd) {
+		case BIO_READ:
+		case BIO_GETATTR:
+			if (cp->acr == 0)
+				error = EPERM;
+			break;
+		case BIO_WRITE:
+			if (cp->acw == 0)
+				error = EPERM;
+			break;
+		case BIO_SETATTR:
+		case BIO_DELETE:
+		case BIO_FORMAT:
+			if ((cp->acw == 0) || (cp->ace == 0))
+				error = EPERM;
+			break;
+		default:
+			error = EPERM;
+			break;
+		}
+	}
+	/* if provider is marked for error, don't disturb */
+	if (!error)
+		error = bp->bio_to->error;
+	if (error) {
+		bp->bio_error = error;
+		/* finish_stats(&bp->stats); */
+
+		g_trace(G_T_BIO,
+		    "bio_request(%p) from %p(%s) to %p(%s) cmd %d error %d\n",
+		    bp, bp->bio_from, bp->bio_from->geom->name,
+		    bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error);
+		g_bioq_enqueue_tail(bp, &g_bio_run_up);
+		mtx_lock(&Giant);
+		wakeup(&g_wait_up);
+		mtx_unlock(&Giant);
+	} else {
+		g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
+		    bp, bp->bio_from, bp->bio_from->geom->name,
+		    bp->bio_to, bp->bio_to->name, bp->bio_cmd);
+		g_bioq_enqueue_tail(bp, &g_bio_run_down);
+		mtx_lock(&Giant);
+		wakeup(&g_wait_down);
+		mtx_unlock(&Giant);
+	}
+}
+
+void
+g_io_deliver(struct bio *bp)
+{
+
+	g_trace(G_T_BIO,
+	    "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d",
+	    bp, bp->bio_from, bp->bio_from->geom->name,
+	    bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error);
+	/* finish_stats(&bp->stats); */
+
+	g_bioq_enqueue_tail(bp, &g_bio_run_up);
+
+	mtx_lock(&Giant);
+	wakeup(&g_wait_up);
+	mtx_unlock(&Giant);
+}
+
+void
+g_io_schedule_down(struct thread *tp __unused)
+{
+	struct bio *bp;
+
+	for(;;) {
+		bp = g_bioq_first(&g_bio_run_down);
+		if (bp == NULL)
+			break;
+		bp->bio_to->geom->start(bp);
+	}
+}
+
+void
+g_io_schedule_up(struct thread *tp __unused)
+{
+	struct bio *bp;
+	struct g_consumer *cp;
+
+	for(;;) {
+		bp = g_bioq_first(&g_bio_run_up);
+		if (bp == NULL)
+			break;
+
+		cp = bp->bio_from;
+
+		bp->bio_flags |= BIO_DONE;
+		atomic_add_int(&cp->biocount, -1);
+		if (bp->bio_done != NULL) {
+			bp->bio_done(bp);
+		} else {
+			mtx_lock(&Giant);
+			wakeup(bp);
+			mtx_unlock(&Giant);
+		}
+	}
+}
+
+void *
+g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
+{
+	struct bio *bp;
+	void *ptr;
+	int errorc;
+
+        do {
+		bp = g_new_bio();
+		bp->bio_cmd = BIO_READ;
+		bp->bio_done = NULL;
+		bp->bio_offset = offset;
+		bp->bio_length = length;
+		ptr = g_malloc(length, M_WAITOK);
+		bp->bio_data = ptr;
+		g_io_request(bp, cp);
+		while ((bp->bio_flags & BIO_DONE) == 0) {
+			mtx_lock(&Giant);
+			tsleep(bp, 0, "g_read_data", hz / 10);
+			mtx_unlock(&Giant);
+		}
+		errorc = bp->bio_error;
+		if (error != NULL)
+			*error = errorc;
+		g_destroy_bio(bp);
+		if (errorc) {
+			g_free(ptr);
+			ptr = NULL;
+		}
+		if (errorc == EBUSY)
+			tsleep(&errorc, 0, "g_read_data_busy", hz);
+        } while (errorc == EBUSY);
+	return (ptr);
+}