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-rw-r--r--libblkid/src/superblocks/bcache.c79
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 }
+ }
+};
+