xfs: don't use the incore struct xfs_sb for offsets into struct xfs_dsb
Currently, the XFS_SB_CRC_OFF macro uses the incore superblock struct
(xfs_sb) to compute the address of sb_crc within the ondisk superblock
struct (xfs_dsb). This is a landmine if we ever change the layout of
the incore superblock (as we're about to do), so redefine the macro
to use xfs_dsb to compute the layout of xfs_dsb.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 61f51bec..e1bfee0 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -90,8 +90,7 @@ struct xfs_ifork;
#define XFSLABEL_MAX 12
/*
- * Superblock - in core version. Must match the ondisk version below.
- * Must be padded to 64 bit alignment.
+ * Superblock - in core version. Must be padded to 64 bit alignment.
*/
typedef struct xfs_sb {
uint32_t sb_magicnum; /* magic number == XFS_SB_MAGIC */
@@ -178,10 +177,8 @@ typedef struct xfs_sb {
/* must be padded to 64 bit alignment */
} xfs_sb_t;
-#define XFS_SB_CRC_OFF offsetof(struct xfs_sb, sb_crc)
-
/*
- * Superblock - on disk version. Must match the in core version above.
+ * Superblock - on disk version.
* Must be padded to 64 bit alignment.
*/
struct xfs_dsb {
@@ -265,6 +262,8 @@ struct xfs_dsb {
/* must be padded to 64 bit alignment */
};
+#define XFS_SB_CRC_OFF offsetof(struct xfs_dsb, sb_crc)
+
/*
* Misc. Flags - warning - these will be cleared by xfs_repair unless
* a feature bit is set when the flag is used.
diff --git a/fs/xfs/libxfs/xfs_ondisk.h b/fs/xfs/libxfs/xfs_ondisk.h
index e8cdd77..23c133f 100644
--- a/fs/xfs/libxfs/xfs_ondisk.h
+++ b/fs/xfs/libxfs/xfs_ondisk.h
@@ -85,6 +85,7 @@ xfs_check_ondisk_structs(void)
XFS_CHECK_STRUCT_SIZE(xfs_attr_leaf_name_remote_t, 12);
*/
+ XFS_CHECK_OFFSET(struct xfs_dsb, sb_crc, 224);
XFS_CHECK_OFFSET(xfs_attr_leaf_name_local_t, valuelen, 0);
XFS_CHECK_OFFSET(xfs_attr_leaf_name_local_t, namelen, 2);
XFS_CHECK_OFFSET(xfs_attr_leaf_name_local_t, nameval, 3);
