[PATCH 040/119] xfs: create helpers for mapping, unmapping, and converting file fork extents

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

Create two helper functions to assist with mapping, unmapping, and
converting flag status of extents in a file's data/attr forks.  For
non-shared files we can use the _alloc, _free, and _convert functions;
when reflink comes these functions will be augmented to deal with
shared extents.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_rmap.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)


diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
index f92eaa1..76fc5c2 100644
--- a/fs/xfs/libxfs/xfs_rmap.c
+++ b/fs/xfs/libxfs/xfs_rmap.c
@@ -1123,11 +1123,53 @@ done:
        return error;
 }
 
+/*
+ * Convert an unwritten extent to a real extent or vice versa.
+ */
+STATIC int
+xfs_rmap_convert(
+       struct xfs_btree_cur    *cur,
+       xfs_agblock_t           bno,
+       xfs_extlen_t            len,
+       bool                    unwritten,
+       struct xfs_owner_info   *oinfo)
+{
+       return __xfs_rmap_convert(cur, bno, len, unwritten, oinfo);
+}
+
 #undef NEW
 #undef LEFT
 #undef RIGHT
 #undef PREV
 
+/*
+ * Find an extent in the rmap btree and unmap it.
+ */
+STATIC int
+xfs_rmap_unmap(
+       struct xfs_btree_cur    *cur,
+       xfs_agblock_t           bno,
+       xfs_extlen_t            len,
+       bool                    unwritten,
+       struct xfs_owner_info   *oinfo)
+{
+       return __xfs_rmap_free(cur, bno, len, unwritten, oinfo);
+}
+
+/*
+ * Find an extent in the rmap btree and map it.
+ */
+STATIC int
+xfs_rmap_map(
+       struct xfs_btree_cur    *cur,
+       xfs_agblock_t           bno,
+       xfs_extlen_t            len,
+       bool                    unwritten,
+       struct xfs_owner_info   *oinfo)
+{
+       return __xfs_rmap_alloc(cur, bno, len, unwritten, oinfo);
+}
+
 struct xfs_rmapbt_query_range_info {
        xfs_rmapbt_query_range_fn       fn;
        void                            *priv;