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>

fs/xfs/xfs_bmap_util.c

@@ -88,7 +88,6 @@ int
 xfs_bmap_rtalloc(
 	struct xfs_bmalloca	*ap)	/* bmap alloc argument struct */
 {
-	xfs_alloctype_t	atype = 0;	/* type for allocation routines */
 	int		error;		/* error return value */
 	xfs_mount_t	*mp;		/* mount point structure */
 	xfs_extlen_t	prod = 0;	/* product factor for allocators */
@@ -155,18 +154,14 @@ xfs_bmap_rtalloc(
 	/*
 	 * Realtime allocation, done through xfs_rtallocate_extent.
 	 */
-	atype = ap->blkno == 0 ?  XFS_ALLOCTYPE_ANY_AG : XFS_ALLOCTYPE_NEAR_BNO;
 	do_div(ap->blkno, mp->m_sb.sb_rextsize);
 	rtb = ap->blkno;
 	ap->length = ralen;
-	if ((error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1, ap->length,
-				&ralen, atype, ap->wasdel, prod, &rtb)))
-		return error;
-	if (rtb == NULLFSBLOCK && prod > 1 &&
-	    (error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1,
-					   ap->length, &ralen, atype,
-					   ap->wasdel, 1, &rtb)))
+	error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1, ap->length,
+				&ralen, ap->wasdel, prod, &rtb);
+	if (error)
 		return error;
+
 	ap->blkno = rtb;
 	if (ap->blkno != NULLFSBLOCK) {
 		ap->blkno *= mp->m_sb.sb_rextsize;

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;
 }

fs/xfs/xfs_rtalloc.h

@@ -40,7 +40,6 @@ 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 */
@@ -122,7 +121,7 @@ int xfs_rtfree_range(struct xfs_mount *mp, struct xfs_trans *tp,
 
 
 #else
-# define xfs_rtallocate_extent(t,b,min,max,l,a,f,p,rb)  (ENOSYS)
+# define xfs_rtallocate_extent(t,b,min,max,l,f,p,rb)    (ENOSYS)
 # define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
 # define xfs_rtpick_extent(m,t,l,rb)                    (ENOSYS)
 # define xfs_growfs_rt(mp,in)                           (ENOSYS)