[XFS] Cleanup maxrecs calculation.

Clean up the way the maximum and minimum records for the btree blocks are
calculated. For the alloc and inobt btrees all the values are
pre-calculated in xfs_mount_common, and we switch the current loop around
the ugly generic macros that use cpp token pasting to generate type names
to two small helpers in normal C code. For the bmbt and bmdr trees these
helpers also exist, but can be called during runtime, too. Here we also
kill various macros dealing with them and inline the logic into the
get_minrecs / get_maxrecs / get_dmaxrecs methods in xfs_bmap_btree.c.

Note that all these new helpers take an xfs_mount * argument which will be
needed to determine the size of a btree block once we add support for
extended btree blocks with CRCs and other RAS information.

SGI-PV: 988146

SGI-Modid: xfs-linux-melb:xfs-kern:32292a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 66 insertions, 8 deletions

diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index c5eeb3241e2..853828c6b45 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -66,6 +66,7 @@ xfs_extent_state(
  */
 void
 xfs_bmdr_to_bmbt(
+	struct xfs_mount	*mp,
 	xfs_bmdr_block_t	*dblock,
 	int			dblocklen,
 	xfs_bmbt_block_t	*rblock,
@@ -83,11 +84,11 @@ xfs_bmdr_to_bmbt(
 	rblock->bb_numrecs = dblock->bb_numrecs;
 	rblock->bb_leftsib = cpu_to_be64(NULLDFSBNO);
 	rblock->bb_rightsib = cpu_to_be64(NULLDFSBNO);
-	dmxr = (int)XFS_BTREE_BLOCK_MAXRECS(dblocklen, xfs_bmdr, 0);
+	dmxr = xfs_bmdr_maxrecs(mp, dblocklen, 0);
 	fkp = XFS_BTREE_KEY_ADDR(xfs_bmdr, dblock, 1);
 	tkp = XFS_BMAP_BROOT_KEY_ADDR(rblock, 1, rblocklen);
 	fpp = XFS_BTREE_PTR_ADDR(xfs_bmdr, dblock, 1, dmxr);
-	tpp = XFS_BMAP_BROOT_PTR_ADDR(rblock, 1, rblocklen);
+	tpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
 	dmxr = be16_to_cpu(dblock->bb_numrecs);
 	memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
 	memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
@@ -428,6 +429,7 @@ xfs_bmbt_set_state(
  */
 void
 xfs_bmbt_to_bmdr(
+	struct xfs_mount	*mp,
 	xfs_bmbt_block_t	*rblock,
 	int			rblocklen,
 	xfs_bmdr_block_t	*dblock,
@@ -445,10 +447,10 @@ xfs_bmbt_to_bmdr(
 	ASSERT(be16_to_cpu(rblock->bb_level) > 0);
 	dblock->bb_level = rblock->bb_level;
 	dblock->bb_numrecs = rblock->bb_numrecs;
-	dmxr = (int)XFS_BTREE_BLOCK_MAXRECS(dblocklen, xfs_bmdr, 0);
+	dmxr = xfs_bmdr_maxrecs(mp, dblocklen, 0);
 	fkp = XFS_BMAP_BROOT_KEY_ADDR(rblock, 1, rblocklen);
 	tkp = XFS_BTREE_KEY_ADDR(xfs_bmdr, dblock, 1);
-	fpp = XFS_BMAP_BROOT_PTR_ADDR(rblock, 1, rblocklen);
+	fpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
 	tpp = XFS_BTREE_PTR_ADDR(xfs_bmdr, dblock, 1, dmxr);
 	dmxr = be16_to_cpu(dblock->bb_numrecs);
 	memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
@@ -626,15 +628,36 @@ xfs_bmbt_get_minrecs(
 	struct xfs_btree_cur	*cur,
 	int			level)
 {
-	return XFS_BMAP_BLOCK_IMINRECS(level, cur);
+	if (level == cur->bc_nlevels - 1) {
+		struct xfs_ifork	*ifp;
+
+		ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
+				    cur->bc_private.b.whichfork);
+
+		return xfs_bmbt_maxrecs(cur->bc_mp,
+					ifp->if_broot_bytes, level == 0) / 2;
+	}
+
+	return cur->bc_mp->m_bmap_dmnr[level != 0];
 }
 
-STATIC int
+int
 xfs_bmbt_get_maxrecs(
 	struct xfs_btree_cur	*cur,
 	int			level)
 {
-	return XFS_BMAP_BLOCK_IMAXRECS(level, cur);
+	if (level == cur->bc_nlevels - 1) {
+		struct xfs_ifork	*ifp;
+
+		ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
+				    cur->bc_private.b.whichfork);
+
+		return xfs_bmbt_maxrecs(cur->bc_mp,
+					ifp->if_broot_bytes, level == 0);
+	}
+
+	return cur->bc_mp->m_bmap_dmxr[level != 0];
+
 }
 
 /*
@@ -651,7 +674,10 @@ xfs_bmbt_get_dmaxrecs(
 	struct xfs_btree_cur	*cur,
 	int			level)
 {
-	return XFS_BMAP_BLOCK_DMAXRECS(level, cur);
+	if (level != cur->bc_nlevels - 1)
+		return cur->bc_mp->m_bmap_dmxr[level != 0];
+	return xfs_bmdr_maxrecs(cur->bc_mp, cur->bc_private.b.forksize,
+				level == 0);
 }
 
 STATIC void
@@ -871,3 +897,35 @@ xfs_bmbt_init_cursor(
 
 	return cur;
 }
+
+/*
+ * Calculate number of records in a bmap btree block.
+ */
+int
+xfs_bmbt_maxrecs(
+	struct xfs_mount	*mp,
+	int			blocklen,
+	int			leaf)
+{
+	blocklen -= sizeof(struct xfs_btree_lblock);
+
+	if (leaf)
+		return blocklen / sizeof(xfs_bmbt_rec_t);
+	return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t));
+}
+
+/*
+ * Calculate number of records in a bmap btree inode root.
+ */
+int
+xfs_bmdr_maxrecs(
+	struct xfs_mount	*mp,
+	int			blocklen,
+	int			leaf)
+{
+	blocklen -= sizeof(xfs_bmdr_block_t);
+
+	if (leaf)
+		return blocklen / sizeof(xfs_bmdr_rec_t);
+	return blocklen / (sizeof(xfs_bmdr_key_t) + sizeof(xfs_bmdr_ptr_t));
+}