xfs: reflect sb features in xfs_mount

Currently on-disk feature checks require decoding the superblock
fileds and so can be non-trivial. We have almost 400 hundred
individual feature checks in the XFS code, so this is a significant
amount of code. To reduce runtime check overhead, pre-process all
the version flags into a features field in the xfs_mount at mount
time so we can convert all the feature checks to a simple flag
check.

There is also a need to convert the dynamic feature flags to update
the m_features field. This is required for attr, attr2 and quota
features. New xfs_mount based wrappers are added for this.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 699066fb9052..f3eb4bf06423 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1131,6 +1131,9 @@ error_cancel:
 		error = xfs_trans_commit(tp);
 		if (error)
 			break;
+
+		/* Ensure the mount RT feature flag is now set. */
+		mp->m_features |= XFS_FEAT_REALTIME;
 	}
 	if (error)
 		goto out_free;