xfs: enable metadata directory feature

Enable the metadata directory feature.  With this feature, all metadata
inodes are placed in the metadata directory, and the only inumbers in
the superblock are the roots of the two directory trees.

The RT device is now sharded into a number of rtgroups, where 0 rtgroups
mean that no RT extents are supported, and the traditional XFS stub RT
bitmap and summary inodes don't exist.  A single rtgroup gives roughly
identical behavior to the traditional RT setup, but now with checksummed
and self identifying free space metadata.

For quota, the quota options are read from the superblock unless
explicitly overridden via mount options.

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

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index ac1fbc6ca28870ffc8764e6aae8770d3bf89607f..e75545f9161d618c2a5ec06649f82776c528db53 100644 (file)
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -414,7 +414,8 @@ xfs_sb_has_ro_compat_feature(
                 XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR | \
                 XFS_SB_FEAT_INCOMPAT_NREXT64 | \
                 XFS_SB_FEAT_INCOMPAT_EXCHRANGE | \
-                XFS_SB_FEAT_INCOMPAT_PARENT)
+                XFS_SB_FEAT_INCOMPAT_PARENT | \
+                XFS_SB_FEAT_INCOMPAT_METADIR)
 
 #define XFS_SB_FEAT_INCOMPAT_UNKNOWN   ~XFS_SB_FEAT_INCOMPAT_ALL
 static inline bool