xfs: refactor creation of bmap btree roots

Now that we've created inode fork helpers to allocate and free btree
roots, create a new bmap btree helper to create a new bmbt root, and
refactor the extents <-> btree conversion functions to use our new
helpers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

3 files changed, 22 insertions, 16 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 9dd1322511d3..6974819f46a7 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -639,7 +639,7 @@ xfs_bmap_btree_to_extents(
 	xfs_trans_binval(tp, cbp);
 	if (cur->bc_bufs[0] == cbp)
 		cur->bc_bufs[0] = NULL;
-	xfs_iroot_realloc(ip, -1, whichfork);
+	xfs_iroot_free(ip, whichfork);
 	ASSERT(ifp->if_broot == NULL);
 	ASSERT((ifp->if_flags & XFS_IFBROOT) == 0);
 	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
@@ -681,22 +681,9 @@ xfs_bmap_extents_to_btree(
 	ASSERT(ifp->if_format == XFS_DINODE_FMT_EXTENTS);
 
 	/*
-	 * Make space in the inode incore. This needs to be undone if we fail
-	 * to expand the root.
-	 */
-	xfs_iroot_realloc(ip, 1, whichfork);
-	ifp->if_flags |= XFS_IFBROOT;
-
-	/*
-	 * Fill in the root.
-	 */
-	block = ifp->if_broot;
-	xfs_btree_init_block_int(mp, block, XFS_BUF_DADDR_NULL,
-				 XFS_BTNUM_BMAP, 1, 1, ip->i_ino,
-				 XFS_BTREE_LONG_PTRS);
-	/*
 	 * Need a cursor.  Can't allocate until bb_level is filled in.
 	 */
+	xfs_bmbt_iroot_alloc(ip, whichfork);
 	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 	cur->bc_ino.flags = wasdel ? XFS_BTCUR_BMBT_WASDEL : 0;
 	/*
@@ -766,6 +753,7 @@ xfs_bmap_extents_to_btree(
 	/*
 	 * Fill in the root key and pointer.
 	 */
+	block = ifp->if_broot;
 	kp = xfs_bmbt_key_addr(mp, block, 1);
 	arp = xfs_bmbt_rec_addr(mp, ablock, 1);
 	kp->br_startoff = cpu_to_be64(xfs_bmbt_disk_get_startoff(arp));
@@ -787,7 +775,7 @@ xfs_bmap_extents_to_btree(
 out_unreserve_dquot:
 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
 out_root_realloc:
-	xfs_iroot_realloc(ip, -1, whichfork);
+	xfs_iroot_free(ip, whichfork);
 	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
 	ASSERT(ifp->if_broot == NULL);
 	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index ae2ea83f5caf..2b0bfcf759a5 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -737,3 +737,20 @@ xfs_bmbt_calc_size(
 {
 	return xfs_btree_calc_size(mp->m_bmap_dmnr, len);
 }
+
+/* Create an incore bmbt btree root block. */
+void
+xfs_bmbt_iroot_alloc(
+	struct xfs_inode	*ip,
+	int			whichfork)
+{
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+
+	xfs_iroot_alloc(ip, whichfork,
+			xfs_bmap_broot_space_calc(ip->i_mount, 1));
+
+	/* Fill in the root. */
+	xfs_btree_init_block_int(ip->i_mount, ifp->if_broot,
+			XFS_BUF_DADDR_NULL, XFS_BTNUM_BMAP, 1, 1, ip->i_ino,
+			XFS_BTREE_LONG_PTRS);
+}
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.h b/fs/xfs/libxfs/xfs_bmap_btree.h
index f1c7928bbc00..59b8620bc61b 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.h
+++ b/fs/xfs/libxfs/xfs_bmap_btree.h
@@ -191,5 +191,6 @@ xfs_bmap_bmdr_space(struct xfs_btree_block *bb)
 	return xfs_bmdr_space_calc(be16_to_cpu(bb->bb_numrecs));
 }
 
+void xfs_bmbt_iroot_alloc(struct xfs_inode *ip, int whichfork);
 
 #endif	/* __XFS_BMAP_BTREE_H__ */