Add code for Ext2FS and ReiserFS labels recognition.

Submitted by:	Stanislav Sedov <stas@310.ru>
PR:		kern/84638
MFC after:	1 week

1 files changed, 113 insertions, 0 deletions

diff --git a/sys/geom/label/g_label_reiserfs.c b/sys/geom/label/g_label_reiserfs.c
new file mode 100644
index 0000000..8ef1ec8
--- /dev/null
+++ b/sys/geom/label/g_label_reiserfs.c
@@ -0,0 +1,113 @@
+/*-
+ * Copyright (c) 2005 Stanislav Sedov
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+
+#include <geom/geom.h>
+#include <geom/label/g_label.h>
+
+#define REISERFS_NEW_DISK_OFFSET 64 * 1024
+#define REISERFS_OLD_DISK_OFFSET 8 * 1024
+#define REISERFS_SUPER_MAGIC	"ReIsEr"
+
+typedef struct resiserfs_sb {
+	uint8_t		fake1[52];
+	char		s_magic[10];
+	uint8_t		fake2[10];
+	uint16_t	s_version;
+	uint8_t		fake3[26];
+	char		s_volume_name[16];
+} reiserfs_sb_t;
+
+static reiserfs_sb_t *
+g_label_reiserfs_read_super(struct g_consumer *cp, off_t offset, off_t len) 
+{
+	reiserfs_sb_t *fs;
+
+	fs = (reiserfs_sb_t *)g_read_data(cp, offset, len, NULL);
+	if (fs == NULL)
+		return (NULL);
+
+	if (strncmp(fs->s_magic, REISERFS_SUPER_MAGIC,
+	    strlen(REISERFS_SUPER_MAGIC)) != 0) {
+		g_free(fs);
+		return (NULL);
+	}
+
+	return (fs);
+}
+
+static void
+g_label_reiserfs_taste(struct g_consumer *cp, char *label, size_t size)
+{
+	struct g_provider *pp;
+	reiserfs_sb_t *fs;
+
+	g_topology_assert_not();
+	pp = cp->provider;
+	label[0] = '\0';
+
+	/* Try old format */
+	fs = g_label_reiserfs_read_super(cp, REISERFS_OLD_DISK_OFFSET,
+	    pp->sectorsize);
+	if (fs == NULL) {
+		/* Try new format */
+		fs = g_label_reiserfs_read_super(cp, REISERFS_NEW_DISK_OFFSET,
+		    pp->sectorsize);
+	}
+	if (fs == NULL)
+		return;
+
+	/* Check version */
+	if (fs->s_version == 2) {
+		G_LABEL_DEBUG(1, "reiserfs file system detected on %s.",
+		    pp->name);
+	} else {
+		goto exit_free;
+	}
+
+	/* Check for volume label */
+	if (fs->s_volume_name[0] == '\0')
+		goto exit_free;
+
+	/* Terminate label */
+	fs->s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
+	strlcpy(label, fs->s_volume_name, size);
+
+exit_free:
+	g_free(fs);
+}
+
+const struct g_label_desc g_label_reiserfs = {
+	.ld_taste = g_label_reiserfs_taste,
+	.ld_dir = "reiserfs"
+};