xfs: add support for large btree blocks

Add support for larger btree blocks that contains a CRC32C checksum,
a filesystem uuid and block number for detecting filesystem
consistency and out of place writes.

[dchinner@redhat.com] Also include an owner field to allow reverse
mappings to be implemented for improved repairability and a LSN
field to so that log recovery can easily determine the last
modification that made it to disk for each buffer.

[dchinner@redhat.com] Add buffer log format flags to indicate the
type of buffer to recovery so that we don't have to do blind magic
number tests to determine what the buffer is.

[dchinner@redhat.com] Modified to fit into the verifier structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/fs/xfs/xfs_alloc_btree.h b/fs/xfs/xfs_alloc_btree.h
index 7e89a2b429dd..e3a3f7424192 100644
--- a/fs/xfs/xfs_alloc_btree.h
+++ b/fs/xfs/xfs_alloc_btree.h
@@ -31,8 +31,10 @@ struct xfs_mount;
  * by blockcount and blockno.  All blocks look the same to make the code
  * simpler; if we have time later, we'll make the optimizations.
  */
-#define XFS_ABTB_MAGIC  0x41425442      /* 'ABTB' for bno tree */
-#define XFS_ABTC_MAGIC  0x41425443      /* 'ABTC' for cnt tree */
+#define XFS_ABTB_MAGIC          0x41425442      /* 'ABTB' for bno tree */
+#define XFS_ABTB_CRC_MAGIC      0x41423342      /* 'AB3B' */
+#define XFS_ABTC_MAGIC          0x41425443      /* 'ABTC' for cnt tree */
+#define XFS_ABTC_CRC_MAGIC      0x41423343      /* 'AB3C' */
 
 /*
  * Data record/key structure
@@ -59,10 +61,10 @@ typedef __be32 xfs_alloc_ptr_t;
 
 /*
  * Btree block header size depends on a superblock flag.
- *
- * (not quite yet, but soon)
  */
-#define XFS_ALLOC_BLOCK_LEN(mp) XFS_BTREE_SBLOCK_LEN
+#define XFS_ALLOC_BLOCK_LEN(mp) \
+        (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+                XFS_BTREE_SBLOCK_CRC_LEN : XFS_BTREE_SBLOCK_LEN)
 
 /*
  * Record, key, and pointer address macros for btree blocks.