From: "Darrick J. Wong" <djwong@kernel.org>

Source kernel commit: a9642049d91105c676526817b527a1a62940888f

Log incompat feature flags in the superblock exist for one purpose: to
protect the contents of a dirty log from replay on a kernel that isn't
prepared to handle those dirty contents.  This means that they can be
cleared if (a) we know the log is clean and (b) we know that there
aren't any other threads in the system that might be setting or relying
upon a log incompat flag.

Therefore, clear the log incompat flags when we've finished recovering
the log, when we're unmounting cleanly, remounting read-only, or
freezing; and provide a function so that subsequent patches can start
using this.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <redacted>
Signed-off-by: Allison Henderson <redacted>
---
 libxfs/xfs_format.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index 37570cf..5d8a129 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h

@@ -495,6 +495,21 @@ xfs_sb_has_incompat_log_feature(
 	return (sbp->sb_features_log_incompat & feature) != 0;
 }
 
+static inline void
+xfs_sb_remove_incompat_log_features(
+	struct xfs_sb	*sbp)
+{
+	sbp->sb_features_log_incompat &= ~XFS_SB_FEAT_INCOMPAT_LOG_ALL;
+}
+
+static inline void
+xfs_sb_add_incompat_log_features(
+	struct xfs_sb	*sbp,
+	unsigned int	features)
+{
+	sbp->sb_features_log_incompat |= features;
+}
+
 /*
  * V5 superblock specific feature checks
  */

-- 
2.7.4