1 files changed, 79 insertions, 0 deletions
diff --git a/libblkid/src/superblocks/bcache.c b/libblkid/src/superblocks/bcache.c
new file mode 100644
index 0000000..aa2dc04
--- /dev/null
+++ b/libblkid/src/superblocks/bcache.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2013 Rolf Fokkens <rolf@fokkens.nl>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ *
+ * Based on code fragments from bcache-tools by Kent Overstreet:
+ * http://evilpiepirate.org/git/bcache-tools.git
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+
+#include "superblocks.h"
+
+#define SB_LABEL_SIZE      32
+#define SB_JOURNAL_BUCKETS 256U
+
+#define node(i, j)         ((i)->d + (j))
+#define end(i)             node(i, le16_to_cpu((i)->keys))
+
+/*
+ * The bcache_super_block is heavily simplified version of struct cache_sb in kernel.
+ * https://github.com/torvalds/linux/blob/master/include/uapi/linux/bcache.h
+ */
+struct bcache_super_block {
+	uint64_t		csum;
+	uint64_t		offset;		/* where this super block was written */
+	uint64_t		version;
+	uint8_t			magic[16];	/* bcache file system identifier */
+	uint8_t			uuid[16];	/* device identifier */
+};
+
+/* magic string */
+#define BCACHE_SB_MAGIC     "\xc6\x85\x73\xf6\x4e\x1a\x45\xca\x82\x65\xf5\x7f\x48\xba\x6d\x81"
+/* magic string len */
+#define BCACHE_SB_MAGIC_LEN (sizeof(BCACHE_SB_MAGIC) - 1)
+/* super block offset */
+#define BCACHE_SB_OFF       0x1000
+/* supper block offset in kB */
+#define BCACHE_SB_KBOFF     (BCACHE_SB_OFF >> 10)
+/* magic string offset within super block */
+#define BCACHE_SB_MAGIC_OFF offsetof (struct bcache_super_block, magic)
+
+static int probe_bcache (blkid_probe pr, const struct blkid_idmag *mag)
+{
+	struct bcache_super_block *bcs;
+
+	bcs = blkid_probe_get_sb(pr, mag, struct bcache_super_block);
+	if (!bcs)
+		return errno ? -errno : BLKID_PROBE_NONE;
+
+	if (le64_to_cpu(bcs->offset) != BCACHE_SB_OFF / 512)
+		return BLKID_PROBE_NONE;
+
+	if (blkid_probe_set_uuid(pr, bcs->uuid) < 0)
+		return BLKID_PROBE_NONE;
+
+	return BLKID_PROBE_OK;
+}
+
+const struct blkid_idinfo bcache_idinfo =
+{
+	.name		= "bcache",
+	.usage		= BLKID_USAGE_OTHER,
+	.probefunc	= probe_bcache,
+	.minsz		= 8192,
+	.magics		=
+	{
+		{
+			.magic = BCACHE_SB_MAGIC,
+			.len   = BCACHE_SB_MAGIC_LEN,
+			.kboff = BCACHE_SB_KBOFF,
+			.sboff = BCACHE_SB_MAGIC_OFF
+		},
+		{ NULL }
+	}
+};
+