xfs: fold xfs_bmbt_init_common into xfs_bmbt_init_cursor

Make the levels initialization in xfs_bmbt_init_cursor conditional
and merge the two helpers.

This requires the fakeroot case to now pass a -1 whichfork directly
into xfs_bmbt_init_cursor, and some special casing for that, but
at least this scheme to deal with the fake btree root is handled and
documented in once place now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: tidy up a multline ternary]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 7381e507b32ba03449c4728b3c11cc8d7e538460..c338c5be4c67a3e660035db5871476ad0aa094d5 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -544,27 +544,10 @@ const struct xfs_btree_ops xfs_bmbt_ops = {
        .keys_contiguous        = xfs_bmbt_keys_contiguous,
 };
 
-static struct xfs_btree_cur *
-xfs_bmbt_init_common(
-       struct xfs_mount        *mp,
-       struct xfs_trans        *tp,
-       struct xfs_inode        *ip,
-       int                     whichfork)
-{
-       struct xfs_btree_cur    *cur;
-
-       ASSERT(whichfork != XFS_COW_FORK);
-
-       cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_BMAP, &xfs_bmbt_ops,
-                       mp->m_bm_maxlevels[whichfork], xfs_bmbt_cur_cache);
-
-       cur->bc_ino.ip = ip;
-       cur->bc_bmap.allocated = 0;
-       return cur;
-}
-
 /*
- * Allocate a new bmap btree cursor.
+ * Create a new bmap btree cursor.
+ *
+ * For staging cursors -1 in passed in whichfork.
  */
 struct xfs_btree_cur *
 xfs_bmbt_init_cursor(
@@ -573,15 +556,34 @@ xfs_bmbt_init_cursor(
        struct xfs_inode        *ip,
        int                     whichfork)
 {
-       struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
        struct xfs_btree_cur    *cur;
+       unsigned int            maxlevels;
 
-       cur = xfs_bmbt_init_common(mp, tp, ip, whichfork);
+       ASSERT(whichfork != XFS_COW_FORK);
 
-       cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
-       cur->bc_ino.forksize = xfs_inode_fork_size(ip, whichfork);
+       /*
+        * The Data fork always has larger maxlevel, so use that for staging
+        * cursors.
+        */
+       switch (whichfork) {
+       case XFS_STAGING_FORK:
+               maxlevels = mp->m_bm_maxlevels[XFS_DATA_FORK];
+               break;
+       default:
+               maxlevels = mp->m_bm_maxlevels[whichfork];
+               break;
+       }
+       cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_BMAP, &xfs_bmbt_ops,
+                       maxlevels, xfs_bmbt_cur_cache);
+       cur->bc_ino.ip = ip;
        cur->bc_ino.whichfork = whichfork;
+       cur->bc_bmap.allocated = 0;
+       if (whichfork != XFS_STAGING_FORK) {
+               struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
 
+               cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
+               cur->bc_ino.forksize = xfs_inode_fork_size(ip, whichfork);
+       }
        return cur;
 }
 
@@ -610,11 +612,7 @@ xfs_bmbt_stage_cursor(
 {
        struct xfs_btree_cur    *cur;
 
-       /* data fork always has larger maxheight */
-       cur = xfs_bmbt_init_common(mp, NULL, ip, XFS_DATA_FORK);
-
-       /* Don't let anyone think we're attached to the real fork yet. */
-       cur->bc_ino.whichfork = XFS_STAGING_FORK;
+       cur = xfs_bmbt_init_cursor(mp, NULL, ip, XFS_STAGING_FORK);
        xfs_btree_stage_ifakeroot(cur, ifake);
        return cur;
 }