The corresponding metadump file's disk layout is as shown below,
|------------------------------|
| struct xfs_metadump_header |
|------------------------------|
| struct xfs_meta_extent 0 |
| Extent 0's data |
| struct xfs_meta_extent 1 |
| Extent 1's data |
| ... |
| struct xfs_meta_extent (n-1) |
| Extent (n-1)'s data |
|------------------------------|
The "struct xfs_metadump_header" is followed by alternating series of "struct
xfs_meta_extent" and the extent itself.
Signed-off-by: Chandan Babu R <chandan.babu@xxxxxxxxxx>
---
include/xfs_metadump.h | 58 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
diff --git a/include/xfs_metadump.h b/include/xfs_metadump.h
index a4dca25c..518cb302 100644
--- a/include/xfs_metadump.h
+++ b/include/xfs_metadump.h
@@ -8,7 +8,9 @@
#define _XFS_METADUMP_H_
#define XFS_MD_MAGIC_V1 0x5846534d /* 'XFSM' */
+#define XFS_MD_MAGIC_V2 0x584D4432 /* 'XMD2' */
+/* Metadump v1 */
typedef struct xfs_metablock {
__be32 mb_magic;
__be16 mb_count;
@@ -23,4 +25,60 @@ typedef struct xfs_metablock {
#define XFS_METADUMP_FULLBLOCKS (1 << 2)
#define XFS_METADUMP_DIRTYLOG (1 << 3)
+/*
+ * Metadump v2
+ *
+ * The following diagram depicts the ondisk layout of the metadump v2 format.
+ *
+ * |------------------------------|
+ * | struct xfs_metadump_header |
+ * |------------------------------|
+ * | struct xfs_meta_extent 0 |
+ * | Extent 0's data |
+ * | struct xfs_meta_extent 1 |
+ * | Extent 1's data |
+ * | ... |
+ * | struct xfs_meta_extent (n-1) |
+ * | Extent (n-1)'s data |
+ * |------------------------------|
+ *
+ * The "struct xfs_metadump_header" is followed by alternating series of "struct
+ * xfs_meta_extent" and the extent itself.
+ */
+struct xfs_metadump_header {
+ __be32 xmh_magic;
+ __be32 xmh_version;
+ __be32 xmh_compat_flags;
+ __be32 xmh_incompat_flags;
+ __be64 xmh_reserved;
+} __packed;
+
+#define XFS_MD2_INCOMPAT_OBFUSCATED (1 << 0)
+#define XFS_MD2_INCOMPAT_FULLBLOCKS (1 << 1)
+#define XFS_MD2_INCOMPAT_DIRTYLOG (1 << 2)
+#define XFS_MD2_INCOMPAT_EXTERNALLOG (1 << 3)
+
+struct xfs_meta_extent {
+ /*
+ * Lowest 54 bits are used to store 512 byte addresses.
+ * Next 2 bits is used for indicating the device.
+ * 00 - Data device
+ * 01 - External log
+ */
+ __be64 xme_addr;
+ /* In units of 512 byte blocks */
+ __be32 xme_len;
+} __packed;
+
+#define XME_ADDR_DEVICE_SHIFT 54
+
+#define XME_ADDR_DADDR_MASK ((1ULL << XME_ADDR_DEVICE_SHIFT) - 1)
+
+/* Extent was copied from the data device */
+#define XME_ADDR_DATA_DEVICE (0ULL << XME_ADDR_DEVICE_SHIFT)
+/* Extent was copied from the log device */
+#define XME_ADDR_LOG_DEVICE (1ULL << XME_ADDR_DEVICE_SHIFT)
+
+#define XME_ADDR_DEVICE_MASK (3ULL << XME_ADDR_DEVICE_SHIFT)
+
#endif /* _XFS_METADUMP_H_ */
--
2.39.1
