Since the days of architectures where page size is smaller than

9660 block size are long gone and we can't use cluster_read on modern
machines, improve the dumb read-ahead.

Doesn't change much on macppc and sparc64, but gives a nice speed boost on
i386 (noone knows why). espie can watch his DVDs again.

espie@ ok (noone else complained)

1 files changed, 19 insertions, 8 deletions

diff --git a/sys/isofs/cd9660/cd9660_vnops.c b/sys/isofs/cd9660/cd9660_vnops.c
index 86e5c2d0483..317b47885e8 100644
--- a/sys/isofs/cd9660/cd9660_vnops.c
+++ b/sys/isofs/cd9660/cd9660_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cd9660_vnops.c,v 1.21 2002/03/14 01:27:03 millert Exp $	*/
+/*	$OpenBSD: cd9660_vnops.c,v 1.22 2002/05/23 14:35:20 art Exp $	*/
 /*	$NetBSD: cd9660_vnops.c,v 1.42 1997/10/16 23:56:57 christos Exp $	*/
 
 /*-
@@ -320,7 +320,7 @@ cd9660_read(v)
 	struct buf *bp;
 	daddr_t lbn, rablock;
 	off_t diff;
-	int rasize, error = 0;
+	int error = 0;
 	long size, n, on;
 
 	if (uio->uio_resid == 0)
@@ -330,6 +330,8 @@ cd9660_read(v)
 	ip->i_flag |= IN_ACCESS;
 	imp = ip->i_mnt;
 	do {
+		struct cluster_info *ci = &ip->i_ci;
+
 		lbn = lblkno(imp, uio->uio_offset);
 		on = blkoff(imp, uio->uio_offset);
 		n = min((u_int)(imp->logical_block_size - on),
@@ -348,15 +350,24 @@ cd9660_read(v)
 			else
 				error = bread(vp, lbn, size, NOCRED, &bp);
 		} else {
-			if (ip->i_ci.ci_lastr + 1 == lbn &&
-			    lblktosize(imp, rablock) < ip->i_size) {
-				rasize = blksize(imp, ip, rablock);
-				error = breadn(vp, lbn, size, &rablock,
-					       &rasize, 1, NOCRED, &bp);
+#define MAX_RA 32
+			if (ci->ci_lastr + 1 == lbn) {
+				daddr_t rablks[MAX_RA];
+				int rasizes[MAX_RA];
+				int i;
+
+				for (i = 0; i < MAX_RA &&
+				    lblktosize(imp, (rablock + i)) < ip->i_size;
+				    i++) {
+					rablks[i] = rablock + i;
+					rasizes[i] = blksize(imp, ip, rablock + i);
+				}
+				error = breadn(vp, lbn, size, rablks,
+				    rasizes, i, NOCRED, &bp);
 			} else
 				error = bread(vp, lbn, size, NOCRED, &bp);
 		}
-		ip->i_ci.ci_lastr = lbn;
+		ci->ci_lastr = lbn;
 		n = min(n, size - bp->b_resid);
 		if (error) {
 			brelse(bp);