[XFS] split up xfs_btree_init_cursor

xfs_btree_init_cursor contains close to little shared code for the
different btrees and will get even more non-common code in the future.
Split it up into one routine per btree type.

Because xfs_btree_dup_cursor needs to call the init routine for a generic
btree cursor add a new btree operation vector that contains a dup_cursor
method that initializes a new cursor based on an existing one.

The btree operations vector is based on an idea and code from Dave Chinner
and will grow more entries later during this series.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32176a

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_alloc_btree.h b/fs/xfs/xfs_alloc_btree.h
index 5bd1a2c8bd07..60735384a4ce 100644
--- a/fs/xfs/xfs_alloc_btree.h
+++ b/fs/xfs/xfs_alloc_btree.h
@@ -152,4 +152,9 @@ extern int xfs_alloc_lookup_le(struct xfs_btree_cur *cur, xfs_agblock_t bno,
 extern int xfs_alloc_update(struct xfs_btree_cur *cur, xfs_agblock_t bno,
                                 xfs_extlen_t len);
 
+
+extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
+                struct xfs_trans *, struct xfs_buf *,
+                xfs_agnumber_t, xfs_btnum_t);
+
 #endif  /* __XFS_ALLOC_BTREE_H__ */