1 files changed, 136 insertions, 0 deletions

diff --git a/libblkid/src/superblocks/bcache.c b/libblkid/src/superblocks/bcache.c
new file mode 100644
index 000000000..b3e397ba1
--- /dev/null
+++ b/libblkid/src/superblocks/bcache.c
@@ -0,0 +1,136 @@
+/*
+ * 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"
+#include "crc64.h"
+
+#define SB_LABEL_SIZE      32
+#define SB_JOURNAL_BUCKETS 256U
+
+#define node(i, j)         ((i)->d + (j))
+#define end(i)             node(i, (i)->keys)
+
+static const char bcache_magic[] = {
+	0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
+	0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81
+};
+
+struct bcache_super_block {
+	uint64_t		csum;
+	uint64_t		offset;	/* sector where this sb was written */
+	uint64_t		version;
+
+	uint8_t			magic[16];
+
+	uint8_t			uuid[16];
+	union {
+		uint8_t		set_uuid[16];
+		uint64_t	set_magic;
+	};
+	uint8_t			label[SB_LABEL_SIZE];
+
+	uint64_t		flags;
+	uint64_t		seq;
+	uint64_t		pad[8];
+
+	union {
+	struct {
+		/* Cache devices */
+		uint64_t	nbuckets;	/* device size */
+
+		uint16_t	block_size;	/* sectors */
+		uint16_t	bucket_size;	/* sectors */
+
+		uint16_t	nr_in_set;
+		uint16_t	nr_this_dev;
+	};
+	struct {
+		/* Backing devices */
+		uint64_t	data_offset;
+
+		/*
+		 * block_size from the cache device section is still used by
+		 * backing devices, so don't add anything here until we fix
+		 * things to not need it for backing devices anymore
+		 */
+	};
+	};
+
+	uint32_t		last_mount;	/* time_t */
+
+	uint16_t		first_bucket;
+	union {
+		uint16_t	njournal_buckets;
+		uint16_t	keys;
+	};
+	uint64_t		d[SB_JOURNAL_BUCKETS];	/* journal buckets */
+};
+
+/* magic string */
+#define BCACHE_SB_MAGIC     bcache_magic
+/* magic string len */
+#define BCACHE_SB_MAGIC_LEN sizeof (bcache_magic)
+/* 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 uint64_t bcache_crc64(struct bcache_super_block *bcs)
+{
+	unsigned char *data = (unsigned char *) bcs;
+	size_t sz;
+
+	data += 8;		/* skip csum field */
+	sz = (unsigned char *) end(bcs) - data;
+
+	return crc64(0xFFFFFFFFFFFFFFFFULL, data, sz) ^ 0xFFFFFFFFFFFFFFFFULL;
+}
+
+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_verify_csum(pr, bcache_crc64(bcs), le64_to_cpu(bcs->csum)))
+		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 }
+	}
+};
+