xfs: simplify xfs_rtallocate_extent

We can deduce the allocation type from the bno argument, and do the
return without prod much simpler internally.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix the macro for the non-rt build]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 802bcc3..c57aa7f 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1093,7 +1093,6 @@ xfs_rtallocate_extent(
 	xfs_extlen_t	minlen,		/* minimum length to allocate */
 	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 	xfs_extlen_t	*len,		/* out: actual length allocated */
-	xfs_alloctype_t	type,		/* allocation type XFS_ALLOCTYPE... */
 	int		wasdel,		/* was a delayed allocation extent */
 	xfs_extlen_t	prod,		/* extent product factor */
 	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
@@ -1123,27 +1122,16 @@ xfs_rtallocate_extent(
 		}
 	}
 
+retry:
 	sumbp = NULL;
-	/*
-	 * Allocate by size, or near another block, or exactly at some block.
-	 */
-	switch (type) {
-	case XFS_ALLOCTYPE_ANY_AG:
+	if (bno == 0) {
 		error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
 				&sumbp,	&sb, prod, &r);
-		break;
-	case XFS_ALLOCTYPE_NEAR_BNO:
+	} else {
 		error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
 				len, &sumbp, &sb, prod, &r);
-		break;
-	case XFS_ALLOCTYPE_THIS_BNO:
-		error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen,
-				len, &sumbp, &sb, prod, &r);
-		break;
-	default:
-		error = -EIO;
-		ASSERT(0);
 	}
+
 	if (error)
 		return error;
 
@@ -1158,7 +1146,11 @@ xfs_rtallocate_extent(
 			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
 		else
 			xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
+	} else if (prod > 1) {
+		prod = 1;
+		goto retry;
 	}
+
 	*rtblock = r;
 	return 0;
 }