[XFS] Undo bit ops cleanup mod due to regression on 32-bit powermac
platform.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30559a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index ca83ddf..47082c0 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -73,6 +73,18 @@
  */
 
 /*
+ * xfs_lowbit32: get low bit set out of 32-bit argument, -1 if none set.
+ */
+STATIC int
+xfs_lowbit32(
+	__uint32_t	v)
+{
+	if (v)
+		return ffs(v) - 1;
+	return -1;
+}
+
+/*
  * Allocate space to the bitmap or summary file, and zero it, for growfs.
  */
 STATIC int				/* error */
@@ -432,7 +444,6 @@
 	}
 	bbno = XFS_BITTOBLOCK(mp, bno);
 	i = 0;
-	ASSERT(minlen != 0);
 	log2len = xfs_highbit32(minlen);
 	/*
 	 * Loop over all bitmap blocks (bbno + i is current block).
@@ -601,8 +612,6 @@
 	xfs_suminfo_t	sum;		/* summary information for extents */
 
 	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
-	ASSERT(maxlen != 0);
-
 	/*
 	 * Loop over all the levels starting with maxlen.
 	 * At each level, look at all the bitmap blocks, to see if there
@@ -660,9 +669,6 @@
 		*rtblock = NULLRTBLOCK;
 		return 0;
 	}
-	ASSERT(minlen != 0);
-	ASSERT(maxlen != 0);
-
 	/*
 	 * Loop over sizes, from maxlen down to minlen.
 	 * This time, when we do the allocations, allow smaller ones
@@ -1948,7 +1954,6 @@
 				  nsbp->sb_blocksize * nsbp->sb_rextsize);
 		nsbp->sb_rextents = nsbp->sb_rblocks;
 		do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
-		ASSERT(nsbp->sb_rextents != 0);
 		nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
 		nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
 		nrsumsize =