xfs: make xfs_rtblock_t a segmented address like xfs_fsblock_t

Now that we've finished adding allocation groups to the realtime volume,
let's make the file block mapping address (xfs_rtblock_t) a segmented
value just like we do on the data device.  This means that group number
and block number conversions can be done with shifting and masking
instead of integer division.

While in theory we could continue caching the rgno shift value in
m_rgblklog, the fact that we now always use the shift value means that
we have an opportunity to increase the redundancy of the rt geometry by
storing it in the ondisk superblock and adding more sb verifier code.
Extend the sueprblock to store the rgblklog value.

Now that we have segmented addresses, set the correct values in
m_groups[XG_TYPE_RTG] so that the xfs_group helpers work correctly.

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

1 files changed, 16 insertions, 5 deletions

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index a29a181e6840..4db022c189e1 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -26,6 +26,7 @@
 #include "xfs_icache.h"
 #include "xfs_rtbitmap.h"
 #include "xfs_rtgroup.h"
+#include "xfs_sb.h"
 
 struct kmem_cache	*xfs_trans_cache;
 
@@ -547,6 +548,18 @@ xfs_trans_apply_sb_deltas(
 	}
 	if (tp->t_rextsize_delta) {
 		be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
+
+		/*
+		 * Because the ondisk sb records rtgroup size in units of rt
+		 * extents, any time we update the rt extent size we have to
+		 * recompute the ondisk rtgroup block log.  The incore values
+		 * will be recomputed in xfs_trans_unreserve_and_mod_sb.
+		 */
+		if (xfs_has_rtgroups(tp->t_mountp)) {
+			sbp->sb_rgblklog = xfs_compute_rgblklog(
+						be32_to_cpu(sbp->sb_rgextents),
+						be32_to_cpu(sbp->sb_rextsize));
+		}
 		whole = 1;
 	}
 	if (tp->t_rbmblocks_delta) {
@@ -673,11 +686,9 @@ xfs_trans_unreserve_and_mod_sb(
 	mp->m_sb.sb_dblocks += tp->t_dblocks_delta;
 	mp->m_sb.sb_agcount += tp->t_agcount_delta;
 	mp->m_sb.sb_imax_pct += tp->t_imaxpct_delta;
-	mp->m_sb.sb_rextsize += tp->t_rextsize_delta;
-	if (tp->t_rextsize_delta) {
-		mp->m_rtxblklog = log2_if_power2(mp->m_sb.sb_rextsize);
-		mp->m_rtxblkmask = mask64_if_power2(mp->m_sb.sb_rextsize);
-	}
+	if (tp->t_rextsize_delta)
+		xfs_mount_sb_set_rextsize(mp, &mp->m_sb,
+				mp->m_sb.sb_rextsize + tp->t_rextsize_delta);
 	mp->m_sb.sb_rbmblocks += tp->t_rbmblocks_delta;
 	mp->m_sb.sb_rblocks += tp->t_rblocks_delta;
 	mp->m_sb.sb_rextents += tp->t_rextents_delta;