From 2873bdf0957ae50352c21407c20b7d51e6c2f1d3 Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Wed, 10 Aug 2016 11:29:36 +1000 Subject: [PATCH] xfs: remove the magic numbers in xfs_btree_block-related len macros Source kernel commit: ad70328a503fae813a563dbe97dd3466ac079e8e replace the magic numbers by offsetof(...) and sizeof(...), and add two extra checks on xfs_check_ondisk_structs() [dchinner: renamed header structures to be more descriptive] Signed-off-by: Hou Tao Reviewed-by: Carlos Maiolino Signed-off-by: Dave Chinner --- libxfs/xfs_format.h | 66 ++++++++++++++++++++++++++++----------------- 1 file changed, 41 insertions(+), 25 deletions(-) diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h index f89b6e0fc..a7c23a647 100644 --- a/libxfs/xfs_format.h +++ b/libxfs/xfs_format.h @@ -1435,41 +1435,57 @@ typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t; * with the crc feature bit, and all accesses to them must be conditional on * that flag. */ +/* short form block header */ +struct xfs_btree_block_shdr { + __be32 bb_leftsib; + __be32 bb_rightsib; + + __be64 bb_blkno; + __be64 bb_lsn; + uuid_t bb_uuid; + __be32 bb_owner; + __le32 bb_crc; +}; + +/* long form block header */ +struct xfs_btree_block_lhdr { + __be64 bb_leftsib; + __be64 bb_rightsib; + + __be64 bb_blkno; + __be64 bb_lsn; + uuid_t bb_uuid; + __be64 bb_owner; + __le32 bb_crc; + __be32 bb_pad; /* padding for alignment */ +}; + struct xfs_btree_block { __be32 bb_magic; /* magic number for block type */ __be16 bb_level; /* 0 is a leaf */ __be16 bb_numrecs; /* current # of data records */ union { - struct { - __be32 bb_leftsib; - __be32 bb_rightsib; - - __be64 bb_blkno; - __be64 bb_lsn; - uuid_t bb_uuid; - __be32 bb_owner; - __le32 bb_crc; - } s; /* short form pointers */ - struct { - __be64 bb_leftsib; - __be64 bb_rightsib; - - __be64 bb_blkno; - __be64 bb_lsn; - uuid_t bb_uuid; - __be64 bb_owner; - __le32 bb_crc; - __be32 bb_pad; /* padding for alignment */ - } l; /* long form pointers */ + struct xfs_btree_block_shdr s; + struct xfs_btree_block_lhdr l; } bb_u; /* rest */ }; -#define XFS_BTREE_SBLOCK_LEN 16 /* size of a short form block */ -#define XFS_BTREE_LBLOCK_LEN 24 /* size of a long form block */ +/* size of a short form block */ +#define XFS_BTREE_SBLOCK_LEN \ + (offsetof(struct xfs_btree_block, bb_u) + \ + offsetof(struct xfs_btree_block_shdr, bb_blkno)) +/* size of a long form block */ +#define XFS_BTREE_LBLOCK_LEN \ + (offsetof(struct xfs_btree_block, bb_u) + \ + offsetof(struct xfs_btree_block_lhdr, bb_blkno)) /* sizes of CRC enabled btree blocks */ -#define XFS_BTREE_SBLOCK_CRC_LEN (XFS_BTREE_SBLOCK_LEN + 40) -#define XFS_BTREE_LBLOCK_CRC_LEN (XFS_BTREE_LBLOCK_LEN + 48) +#define XFS_BTREE_SBLOCK_CRC_LEN \ + (offsetof(struct xfs_btree_block, bb_u) + \ + sizeof(struct xfs_btree_block_shdr)) +#define XFS_BTREE_LBLOCK_CRC_LEN \ + (offsetof(struct xfs_btree_block, bb_u) + \ + sizeof(struct xfs_btree_block_lhdr)) #define XFS_BTREE_SBLOCK_CRC_OFF \ offsetof(struct xfs_btree_block, bb_u.s.bb_crc) -- 2.50.1