From a6fff888c3f02f1aa918730d800d6d559dcdb7fe Mon Sep 17 00:00:00 2001
From: Gordon Tetlow <gordon@FreeBSD.org>
Date: Mon, 3 Feb 2003 17:14:29 +0000
Subject: Add the GEOM module that makes volume labels useful. A kernel
 compiled with this will cause volume labels to be exposed in
 /dev/vol/<volname>. Currently, there is no conflict resolution if more than
 one FS has the same volume name.

Reviewed by:	phk
---
 sys/geom/geom_vol_ffs.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 sys/geom/geom_vol_ffs.c

diff --git a/sys/geom/geom_vol_ffs.c b/sys/geom/geom_vol_ffs.c
new file mode 100644
index 000000000000..7c9a114358ef
--- /dev/null
+++ b/sys/geom/geom_vol_ffs.c
@@ -0,0 +1,146 @@
+/*-
+ * Copyright (c) 2002, 2003 Gordon Tetlow
+ * 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 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>
+#include <sys/errno.h>
+#ifndef _KERNEL
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/param.h>
+#include <stdlib.h>
+#include <err.h>
+#else
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/bio.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#endif
+
+#include <ufs/ufs/dinode.h>
+#include <ufs/ffs/fs.h>
+
+#include <geom/geom.h>
+#include <geom/geom_slice.h>
+
+#define VOL_FFS_CLASS_NAME "VOL_FFS"
+
+static int superblocks[] = SBLOCKSEARCH;
+
+struct g_vol_ffs_softc {
+	char *	vol;
+};
+
+static int
+g_vol_ffs_start(struct bio *bp __unused)
+{
+	return(0);
+}
+
+static struct g_geom *
+g_vol_ffs_taste(struct g_class *mp, struct g_provider *pp, int flags)
+{
+	struct g_geom *gp;
+	struct g_consumer *cp;
+	struct g_vol_ffs_softc *ms;
+	int error, sb, superblock;
+	struct fs *fs;
+
+	g_trace(G_T_TOPOLOGY, "vol_taste(%s,%s)", mp->name, pp->name);
+	g_topology_assert();
+
+	if (flags == G_TF_NORMAL &&
+	    !strcmp(pp->geom->class->name, VOL_FFS_CLASS_NAME))
+		return (NULL);
+
+	gp = g_slice_new(mp, 1, pp, &cp, &ms, sizeof(*ms), g_vol_ffs_start);
+	if (gp == NULL)
+		return (NULL);
+	g_topology_unlock();
+	/*
+	 * Walk through the standard places that superblocks hide and look
+	 * for UFS magic. If we find magic, then check that the size in the
+	 * superblock corresponds to the size of the underlying provider.
+	 * Finally, look for a volume label and create an appropriate /dev
+	 * entry based on that.
+	 */
+	for (sb=0; (superblock = superblocks[sb]) != -1; sb++) {
+		fs = (struct fs *) g_read_data(cp, superblock,
+			SBLOCKSIZE, &error);
+		if (fs == NULL || error != 0)
+			continue;
+		/* Check for magic and make sure things are the right size */
+		if (fs->fs_magic == FS_UFS1_MAGIC) {
+			if (fs->fs_old_size * fs->fs_fsize !=
+			    (int32_t) pp->mediasize) {
+				g_free(fs);
+				continue;
+			}
+		} else if (fs->fs_magic == FS_UFS2_MAGIC) {
+			if (fs->fs_size * fs->fs_fsize !=
+			    (int64_t) pp->mediasize) {
+				g_free(fs);
+				continue;
+			}
+		} else {
+			g_free(fs);
+			continue;
+		}
+		/* Check for volume label */
+		if (fs->fs_volname[0] == '\0') {
+			g_free(fs);
+			continue;
+		}
+		g_topology_lock();
+		/* Alright, we have a label and a volume name, reconfig. */
+		g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t) 0,
+		    pp->mediasize, pp->sectorsize, "vol/%s",
+		    fs->fs_volname);
+		g_free(fs);
+		g_topology_unlock();
+		break;
+	}
+	g_topology_lock();
+	g_access_rel(cp, -1, 0, 0);
+	if (LIST_EMPTY(&gp->provider)) {
+		g_std_spoiled(cp);
+		return (NULL);
+	}
+	return (gp);
+}
+
+static struct g_class g_vol_ffs_class	= {
+	VOL_FFS_CLASS_NAME,
+	g_vol_ffs_taste,
+	NULL,
+	G_CLASS_INITIALIZER
+};
+
+DECLARE_GEOM_CLASS(g_vol_ffs_class, g_vol_ffs);
-- 
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