xfs: clean up xfs_rtallocate_extent_exact a bit

Before we start doing more surgery on the rt allocator, let's clean up
the exact allocator so that it doesn't change its arguments and uses the
helper introduced in the previous patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 21 insertions, 20 deletions

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 11c58f12bcb2..af357704895d 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -338,10 +338,10 @@ xfs_rtallocate_extent_exact(
 	xfs_rtxlen_t		prod,	/* extent product factor */
 	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 {
-	int			error;
-	xfs_rtxlen_t		i;	/* extent length trimmed due to prod */
-	int			isfree;	/* extent is free */
 	xfs_rtxnum_t		next;	/* next rtext to try (dummy) */
+	xfs_rtxlen_t		alloclen; /* candidate length */
+	int			isfree;	/* extent is free */
+	int			error;
 
 	ASSERT(minlen % prod == 0);
 	ASSERT(maxlen % prod == 0);
@@ -352,25 +352,26 @@ xfs_rtallocate_extent_exact(
 	if (error)
 		return error;
 
-	if (!isfree) {
-		/*
-		 * If not, allocate what there is, if it's at least minlen.
-		 */
-		maxlen = next - start;
-		if (maxlen < minlen)
-			return -ENOSPC;
-
-		/*
-		 * Trim off tail of extent, if prod is specified.
-		 */
-		if (prod > 1 && (i = maxlen % prod)) {
-			maxlen -= i;
-			if (maxlen < minlen)
-				return -ENOSPC;
-		}
+	if (isfree) {
+		/* start to maxlen is all free; allocate it. */
+		*len = maxlen;
+		*rtx = start;
+		return 0;
 	}
 
-	*len = maxlen;
+	/*
+	 * If not, allocate what there is, if it's at least minlen.
+	 */
+	alloclen = next - start;
+	if (alloclen < minlen)
+		return -ENOSPC;
+
+	/* Ensure alloclen is a multiple of prod. */
+	alloclen = xfs_rtalloc_align_len(alloclen, prod);
+	if (alloclen < minlen)
+		return -ENOSPC;
+
+	*len = alloclen;
 	*rtx = start;
 	return 0;
 }