xfs: add frextents to the lazysbcounters when rtgroups enabled

Make the free rt extent count a part of the lazy sb counters when the
realtime groups feature is enabled.  This is possible because the patch
to recompute frextents from the rtbitmap during log recovery predates
the code adding rtgroup support, hence we know that the value will
always be correct during runtime.

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

1 files changed, 19 insertions, 14 deletions

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 118d31e11127..01b5f5b32af4 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -421,6 +421,8 @@ xfs_trans_mod_sb(
 			ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
 		}
 		tp->t_frextents_delta += delta;
+		if (xfs_has_rtgroups(mp))
+			flags &= ~XFS_TRANS_SB_DIRTY;
 		break;
 	case XFS_TRANS_SB_RES_FREXTENTS:
 		/*
@@ -430,6 +432,8 @@ xfs_trans_mod_sb(
 		 */
 		ASSERT(delta < 0);
 		tp->t_res_frextents_delta += delta;
+		if (xfs_has_rtgroups(mp))
+			flags &= ~XFS_TRANS_SB_DIRTY;
 		break;
 	case XFS_TRANS_SB_DBLOCKS:
 		tp->t_dblocks_delta += delta;
@@ -498,20 +502,22 @@ xfs_trans_apply_sb_deltas(
 	}
 
 	/*
-	 * Updating frextents requires careful handling because it does not
-	 * behave like the lazysb counters because we cannot rely on log
-	 * recovery in older kenels to recompute the value from the rtbitmap.
-	 * This means that the ondisk frextents must be consistent with the
-	 * rtbitmap.
+	 * sb_frextents was added to the lazy sb counters when the rt groups
+	 * feature was introduced.  This is possible because we know that all
+	 * kernels supporting rtgroups will also recompute frextents from the
+	 * realtime bitmap.
+	 *
+	 * For older file systems, updating frextents requires careful handling
+	 * because we cannot rely on log recovery in older kernels to recompute
+	 * the value from the rtbitmap.  This means that the ondisk frextents
+	 * must be consistent with the rtbitmap.
 	 *
 	 * Therefore, log the frextents change to the ondisk superblock and
 	 * update the incore superblock so that future calls to xfs_log_sb
 	 * write the correct value ondisk.
-	 *
-	 * Don't touch m_frextents because it includes incore reservations,
-	 * and those are handled by the unreserve function.
 	 */
-	if (tp->t_frextents_delta || tp->t_res_frextents_delta) {
+	if ((tp->t_frextents_delta || tp->t_res_frextents_delta) &&
+	    !xfs_has_rtgroups(tp->t_mountp)) {
 		struct xfs_mount	*mp = tp->t_mountp;
 		int64_t			rtxdelta;
 
@@ -619,7 +625,7 @@ xfs_trans_unreserve_and_mod_sb(
 	}
 
 	ASSERT(tp->t_rtx_res || tp->t_frextents_delta >= 0);
-	if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
+	if (xfs_has_rtgroups(mp) || (tp->t_flags & XFS_TRANS_SB_DIRTY)) {
 		rtxdelta += tp->t_frextents_delta;
 		ASSERT(rtxdelta >= 0);
 	}
@@ -652,10 +658,9 @@ xfs_trans_unreserve_and_mod_sb(
 	mp->m_sb.sb_icount += idelta;
 	mp->m_sb.sb_ifree += ifreedelta;
 	/*
-	 * Do not touch sb_frextents here because we are dealing with incore
-	 * reservation.  sb_frextents is not part of the lazy sb counters so it
-	 * must be consistent with the ondisk rtbitmap and must never include
-	 * incore reservations.
+	 * Do not touch sb_frextents here because it is handled in
+	 * xfs_trans_apply_sb_deltas for file systems where it isn't a lazy
+	 * counter anyway.
 	 */
 	mp->m_sb.sb_dblocks += tp->t_dblocks_delta;
 	mp->m_sb.sb_agcount += tp->t_agcount_delta;