[XFS] make btree root in inode support generic

The bmap btree is rooted in the inode and not in a disk block. Make the
support for this feature more generic by adding a btree flag to for this
feature instead of relying on the XFS_BTNUM_BMAP btnum check.

Also clean up xfs_btree_get_block where this new flag is used.

Based upon a patch from Dave Chinner.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32180a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index 428e81f0e27e..fefbc69e500e 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -170,6 +170,7 @@ typedef struct xfs_btree_cur
         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
         struct xfs_mount        *bc_mp; /* file system mount struct */
         const struct xfs_btree_ops *bc_ops;
+        uint                    bc_flags; /* btree features - below */
         union {
                 xfs_alloc_rec_incore_t  a;
                 xfs_bmbt_irec_t         b;
@@ -201,6 +202,10 @@ typedef struct xfs_btree_cur
         }               bc_private;     /* per-btree type data */
 } xfs_btree_cur_t;
 
+/* cursor flags */
+#define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
+
+
 #define XFS_BTREE_NOERROR       0
 #define XFS_BTREE_ERROR         1