xfs: create incore realtime group structures

Create an incore object that will contain information about a realtime
allocation group.  This will eventually enable us to shard the realtime
section in a similar manner to how we shard the data section, but for
now just a single object for the entire RT subvolume is created.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 616f81045921..867060d60e85 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -176,6 +176,9 @@ typedef struct xfs_sb {
 
 	xfs_ino_t	sb_metadirino;	/* metadata directory tree root */
 
+	xfs_rgnumber_t	sb_rgcount;	/* number of realtime groups */
+	xfs_rtxlen_t	sb_rgextents;	/* size of a realtime group in rtx */
+
 	/* must be padded to 64 bit alignment */
 } xfs_sb_t;