xfs: move RT bitmap and summary information to the rtgroup

Move the pointers to the RT bitmap and summary inodes as well as the
summary cache to the rtgroups structure to prepare for having a
separate bitmap and summary inodes for each rtgroup.

Code using the inodes now needs to operate on a rtgroup.  Where easily
possible such code is converted to iterate over all rtgroups, else
rtgroup 0 (the only one that can currently exist) is hardcoded.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>

1 files changed, 13 insertions, 1 deletions

diff --git a/fs/xfs/libxfs/xfs_rtgroup.h b/fs/xfs/libxfs/xfs_rtgroup.h
index 2c894df723a7..3732f65ba8a1 100644
--- a/fs/xfs/libxfs/xfs_rtgroup.h
+++ b/fs/xfs/libxfs/xfs_rtgroup.h
@@ -12,6 +12,9 @@ struct xfs_mount;
 struct xfs_trans;
 
 enum xfs_rtg_inodes {
+	XFS_RTGI_BITMAP,	/* allocation bitmap */
+	XFS_RTGI_SUMMARY,	/* allocation summary */
+
 	XFS_RTGI_MAX,
 };
 
@@ -26,10 +29,19 @@ struct xfs_rtgroup {
 	struct xfs_group	rtg_group;
 
 	/* per-rtgroup metadata inodes */
-	struct xfs_inode	*rtg_inodes[1 /* hack */];
+	struct xfs_inode	*rtg_inodes[XFS_RTGI_MAX];
 
 	/* Number of blocks in this group */
 	xfs_rtxnum_t		rtg_extents;
+
+	/*
+	 * Cache of rt summary level per bitmap block with the invariant that
+	 * rtg_rsum_cache[bbno] > the maximum i for which rsum[i][bbno] != 0,
+	 * or 0 if rsum[i][bbno] == 0 for all i.
+	 *
+	 * Reads and writes are serialized by the rsumip inode lock.
+	 */
+	uint8_t			*rtg_rsum_cache;
 };
 
 static inline struct xfs_rtgroup *to_rtg(struct xfs_group *xg)